Human Factors and User Experience Issues with Ventricular Assist Device Wearable Components: A Systematic Review

Abstract

Ventricular Assist Devices (VADs) provide continuous mechanical circulatory support during in- and out-of-hospital care. However, limitations of the external wearable components influence patient quality of life. There is insufficient understanding of the issues with such components that combines a holistic viewpoint from both human factors and user (including patient and caregiver) experience perspectives. This paper comprehensively details the issues with VAD wearable systems and proposes a way for human-centered design to bridge the gap, addressing such issues synergistically. Through the review the authors investigated: the user issues caused by wearable components of VADs, and how human factors issues correlate to the VAD user experience. A Boolean search (“ventricular assist” AND “human factors” AND “experience”) for peer-reviewed studies published between 2008 and 2018 returned 338 titles, with 35 relevant studies selected using a PRISMA process for inclusion in cross-study analysis and synthesis. This paper provides design recommendations for the issues found in the literature. Four key focus areas to inform the future design of VAD wearable components were identified—‘Power Supply’, ‘Wearability and Travel Freedom’, ‘The Female Experience’ and ‘Intuitive Handling’. Using design to drive innovation could result in VAD wearable components which better meet or exceed users’ quality of life goals.

Appendices

Appendix A: Comprehensive list of human factors issues found in the literature arranged alphabetically by component including user experience (if present) pertaining to the wearable components of VADs, with corresponding human-centered design opportunities

VAD component	Human factors issue	User experience	Device	Sources	Human-centered design opportunity
Alarms	Acoustic alarming during routine battery exchange		Not specified	35	Buffer batteries; both within controller and implanted e.g. near skin on chest or abdomen area, with method to test working function of both
	Alarm failure (e.g. power supply disconnected from controller and no alarm sounded, or inappropriate alarming resulting in controller failure)		Jarvik 2000	54,90	Design for best practice alarm testing protocols
	Alarm signals too quiet to interrupt sleep		Not specified	35,82	Motion sensor, ramping up to much higher volumes, vibration with ramping up
	Alarms don’t meet the needs of users with physical, vision or hearing impairments		Not specified	83	Design for the ability to turn alarms up louder for hearing impaired users, or louder ramping if quieter alarms are not heard or actioned yet, design alarm with speech outputs and verbal prompts for vision impaired users83
	Audio alarms with speech output and verbal prompts desired		Not specified	34	Design alarms with speech outputs and verbal prompts
	Frequent alarms	Fear, Anxiety	Not specified	4	Design to avoid alarm fatigue
	Linguistic nuances in the translation of device alarm messaging can lead to misunderstandings with consequences for usability and safety		Not specified	83	Employ professional translators and conduct usability testing for understanding especially in languages other than English.83 The article “Importance of Linguistic Details in Alarm Messages of Ventricular Assist Devices” by Schima et al.81 addresses this important issue.81
	Noise and vibrations (Alarm ramping desired, with increase of frequency and volume over time rather than sudden onset)	Irritating, Frightening	Not specified	4,34,35,82,83	More ‘friendly’ alarm sound design e.g. ramping, that still conveys urgency
	Noise irritating, especially when trying to sleep	Mixed feelings, Irritation, Bothered, Upset	Not specified	71	Reduce unnecessary intrusive noise or sudden noise
	Patient is not able to recognize the meaning of the alarm from the acoustic signal, misinterpretation of alarms, unable to differentiate between routine and critical alarms	Confusing	Not specified, Thoratec	34,35,82,83,90	Involve a user experience designer from the early stages of VAD product development, spoken language alarms in combination with noises
	Training required: Ability to recognize and interpret alerts and alarm and take appropriate action e.g. knowing when to contact VAD coordinator		Not specified	49,19	Better UI/UX design of alarms, simplify training with digital learning or training app
	Troubleshooting and handling of alarms (need time to become proficient at handling alarm states)	Confronting, Worry	Not specified	21,60,62,79,82,91	Streamline alarm handling processes based on natural user behavior, make intuitive, better UI/UX of alarms
Batteries	Activities such as contact sports, water sports and swimming, immersion in water and taking a bath prohibited	Difficult to accept	Not specified, HeartMate III, Heartware HVAD	71,87,49,4,19,83	Adopt postauricular percutaneous power delivery technology that avoids abdominal area and allows whole body (not head) to be submerged, remove the percutaneous driveline entirely using TETS technology
	Alters patient balance (problematic when exercising)		Not specified	33	Design a weight-balancing carrying system that can be worn in different ways depending on type of exercise; reduce size and weight of batteries
	Batteries limit comfortable sleeping positions		Not specified	33	Adopt postauricular percutaneous power delivery technology that avoids abdominal area and removes obstruction to comfortable sleeping position
	Batteries worn in holster are hard enough to break a rib if patient falls onto them		Not specified	33	Soft or impact-protecting e.g. D3O padding or casing of hard parts
	Battery charger failure		Heartmate II, HVAD, not specified	54,82	Ensure protocol is implemented so that working charger replacement is available at all times
	Battery clips failure, requiring whole battery replacement		Heartmate II	54	Repairable or replaceable clips
	Battery packs very heavy, especially older models		Not specified	8,71	Modular design (i.e. at driveline) that allows for updating of external peripheral components with older implanted VADs
	Caregiver must handle battery issues and ensure backup batteries are charged		Not specified	79	Design an ambient battery status solution that’s as stress-free as using a watch or wall clock for checking the time—that can be hidden if necessary, e.g. at night
	Completely dependent on batteries, strict requirements for managing reserve power—patients test limits of equipment		Not specified	4,8,71	Buffer batteries; both within controller and implanted e.g. near skin on chest or abdomen area, with method to test working function of both
	Constantly checking battery status and function	Stressful, Fear, Worry	Not specified	64,79	Design an ambient battery status solution that’s as stress-free as using a watch or wall clock for checking the time—that can be made less prominent, e.g. at night
	Failure of battery connections requiring replacement		Heartmate II	54	More durable connections e.g. remove pins, magnetic assistance, connections may be cleaned
	Failure or defect, e.g. failure to recharge, requiring battery replacement		HVAD, not specified	54,82	Design for best practice battery testing protocols
	Forgetting to bring extra batteries, must carry a set of backup batteries as a failed battery can lead to death. Need for battery power during outings and must carry additional batteries and charger for travel and long trips, concern for battery life impacts sense of normalcy	Fear, Dissatisfaction, Restriction	Not specified	4,8,33,71	For day trips, a simple reminder solution for bringing extra components e.g. carry bag with recesses, special pockets or “shadow board” design to be filled by needed components daily; for travel, design a more portable charger solution and backup kit. Implantable backup battery and/or extra backup battery in the controller.
	Frequency of battery change		Not specified	71	Supply batteries that last longer (e.g. minimum 8 h)
	Gets in the way during sexual intimacy	Anxiety, Awkward, Self-conscious	Not specified	33,66	Design more ergonomic batteries with a suitable holding system for more vigorous physical activity, adopt postauricular percutaneous power delivery technology that avoids abdominal area
	Insufficient battery capacity (8 h capacity of HeartMate GoGear considered ideal)	Dissatisfaction	Not specified	35,82,83	Increase battery capacity
	Learning procedures for changing batteries and manipulating battery pack		Not specified	49,4	Design battery exchange procedure to be as seamless as changing the battery on a consumer product e.g. digital camera
	Learning procedures for estimating charge levels during battery operation		Not specified	49	Always show the state of batteries with an ambient battery status solution that’s as stress-free as using a watch or wall clock for checking the time—that can be hidden if necessary, e.g. at night
	Must be checked for damage, including Routine Outpatient Evaluation: Visual inspection of batteries for damage to casing and connectors, and tested for lifetime and charging cycles		Not specified	49,23	Simplify or standardise inspection protocol, simplify training with digital learning or training app
	Not all controllers contain buffer batteries (like the HeartMate III), putting patients at risk of pump support interruption if batteries are mishandled		HVAD	83	Controller should contain buffer battery, consider implanted buffer battery
	Patients with the HeartMate II must mark the batteries after every exchange, because the system does not show the state of the batteries		Heartmate II	68	Always show the state of batteries with an ambient battery status solution that’s as stress-free as using a watch or wall clock for checking the time—that can be hidden if necessary, e.g. at night
	Premature failure with more rapid recharge cycles needed, premature battery end of life (failure of the battery to perform to stated specifications of expected life)	Vexation	Not specified	54	Increase battery durability and cycle life
	Values trade-off between longer support duration with larger/heavier batteries or lighter/smaller batteries with shorter duration		Not specified	83	Offer both options if battery cannot be both small and offer a long (8 h+) duration
	Women specifically find batteries too large and heavy, desire a reduction in size and weight		Not specified	33,82,83	Reduce size, weight and bulk of batteries
Cables	Cable replacement due to e.g. broken connector, gradual degradation, or mistakes in use		Not specified	35,82,83,90	Increase durability, ensure protocol is implemented so that working cable replacement is available at all times
	Cord not long enough: Cord must be sufficiently long so that patient can get into the bathroom at night, otherwise they must e.g. disconnect from the machine and put the batteries back on, reconfigure bedroom layout so power cable can reach the bathroom at night without power interruption, or even remove walls in the house so power cable can reach the bathroom at night without power interruption		Not specified	21,90	Provide a longer cord option, retractable cable solution like a vacuum cleaner, make longer and shorter cables so that patients have options
	Gets in the way during sexual intimacy	Anxiety, Awkward, Encumbered, Deeper intimacy, Adjustment	Not specified	4,66	Cord and cable management solution, adopt postauricular percutaneous power delivery technology that avoids abdominal area and removes obstruction to sexual intimacy, remove the percutaneous driveline entirely using TETS technology
	Hooks in the bathroom ceiling for cable management		Not specified	71	Design a stand-alone caddy or specific cable management solution
	Insufficient cable‐strain relief e.g. cable caught on doorknobs or chair armrests causing sudden blockade, desire for more gradual strain-relief (such as helical, spring-like segment)		Not specified	35,82,83	Design a system with both controller and implanted buffer batteries so that power is not lost with cables that disconnect at a certain force and/or insert helical spring-like segments or retractable component in cable design
	Long cords		Not specified	8	Provide a range of longer and shorter cords, different lengths depending on user need, or retractable cable solution like a vacuum cleaner
	Making sure cords are untangled	Adjustment	Not specified	21,83,90	Cord and cable management solution
	Monitor cable failure		Heartmate II, HVAD	54	Increase durability, ensure protocol is implemented so that working cable replacement is available at all times
	Must be checked for damage		Not specified	49,19	Simplify or standardise inspection protocol, simplify training with digital learning or training app
	Patient cable failure (connecting power module to controller)		Heartmate II, not specified	54	Increase durability, ensure protocol is implemented so that working cable replacement is available at all times
	Sleep without plugging the device into the charging station at night to avoid contending with cords		Not specified	33	Adopt postauricular percutaneous power delivery technology that avoids abdominal area and removes obstruction to comfortable sleeping position, remove the percutaneous driveline entirely using TETS technology
Carry bag	Bag used to carry additional paraphernalia e.g. wallet, medical documents, cell phone, or glasses; additional pockets desired to carry extra belongings		Not specified	33,35,82	Design the bag for the way that it is used, not in opposition to it; provide pockets for extra belongings
	Discomfort		Not specified	82	Design investigation to determine cause of discomfort
	Dust or dirt getting into bag		Not specified	35	Design bag to be dust/dirt-resistant with integrated weatherproof cover e.g. like a high-end camera bag, design with easily washable materials
	Female patients regard the bag as too heavy		Not specified	82,83	Reduce overall weight of components, reduce weight of bag fabric
	Hard to wear an all-in-one bag plus a handbag/purse		Not specified	33	Inner-bag solution to be used with patient-preferred bag, provide feminine bag solution with multiple strap options, design a convertible shoulder-bag to backpack
	Hook for the equipment bag needed in bathroom		Not specified	71	Design a stand-alone equipment stand or caddy
	Identification of the VAD (on the bag exterior) desired		Not specified	34	Identification on bag interior e.g. with brightly colored lining, which can be opened and displayed when desired
	Large transportation bags impede life quality and increase the risk of dropping	Impedance	Not specified	82,83	Reduce size and bulk of bags, find solution to reduce accidental dropping
	No extra space provided to carry extra batteries or controllers despite this being recommended, patients using additional shoulder bags, backpacks or plastic bags to carry extra batteries or spare controllers		Not specified	29,35	Provide expandable compartments or two-piece bag system
	Nowhere to put bag when sitting in task chairs (e.g. office)		Not specified	33	Design bag to be comfortably worn while sitting
	Optional brace system desired		Not specified	35	Provide various strap/brace options
	Ordinary handbag/purse used in lieu of carry bag for social event; more inconspicuous than manufacturer-provided bag but need continually alternate sides worn due to weight		Not specified	33	Inner-bag solution to be used with patient-preferred bag, provide feminine bag solution with multiple strap options
	Overheating of the controller (partially due to the protective bag)		Not specified	35	Use heat dispersing materials and mesh sections that can be opened up optionally to disperse heat
	Problems with carabiner and ring strap attachment to the bag—carabiner opened or cables/other parts becoming tangled		Not specified	35	Design alternative attachment methods for carry strap that don’t interfere with VAD components
	Shoulder strap rubs on abdominal region skin when using bag belts		Not specified	35	Design well-fitting bag straps and configurations with non-abrasive materials
	Sleeping by hugging the bag all night		Not specified	33	Adopt postauricular percutaneous power delivery technology that avoids abdominal area and removes obstruction to comfortable sleeping position, pillow-like padded bag for sleeping with33 for batteries and controller connected to abdominal driveline
	Strap painful to carry/causing pain		Not specified	82	Padded strap design, balance weight with multiple straps, reduce overall weight of components
	Tab holding the ring confused with a short loop of cable coming out of the bag		Not specified	35	Design a textured tab or zipper pull that cannot be confused with other components
	Too large, females in particular desire a reduction in size		Not specified	35,82,83	Reduce size of all external components
	Unilateral strap does not allow weight balancing of components, need to alternate shoulders		Not specified	33,35	Design a backpack, or shoulder bag that converts into a backpack, or inner-bag solution to be used with patient-preferred bag
	Unintentionally dropped (causes sudden jerking on the driveline)		Not specified	33,35,82,83	More stable and secure luggage solution, design a system with both controller and implanted buffer batteries so that power is not lost with cables that disconnect at a certain force and/or insert helical spring-like segments or retractable component in driveline design
	Unintentionally dropped bag during changing clothes		Not specified	82	Adopt protocol for changing clothes using bed or chair to rest bag on, adopt postauricular percutaneous power delivery technology that avoids abdominal area and removes obstruction and complexity when changing clothes
	Unsafe or unstable		Not specified	35	Design investigation to determine cause of instability or insecurity
	Using alternative bags other than that provided by the manufacturer		Not specified	35,71,83	Design a light inner-bag solution that can be placed inside a bag of patient’s preference
	Water getting into bag		Not specified	35	Design bag to be weather-resistant with integrated waterproof cover e.g. like a high-end camera bag
Connectors	Afraid of device becoming unplugged if cables are pulled on public transport	Afraid	Not specified	71	Connector system with guard or two-step disconnection process to reduce accidental disconnection by force only (with consideration for override option in case of emergency)
	Color‐coded connection system desired, standardisation of color-coding of connectors between different VAD manufacturers desired		Not specified	34,83,90	Implement color-coding and shape-coding (for color-blind users) of connection system, investigate feasibility of standardized color-coding between manufacturers or common replacement parts
	Connectors become less firm		Not specified	54	Increase durability, ensure protocol is implemented so that working cable replacement is available at all times
	Connectors difficult to reconnect		Thoratec, Heartware	34	Improve usability and human factors, ensure guides slide smoothly with adequate tolerances, magnetic assistance
	Degradation of connector housings and connection mechanisms		Not specified	35	Increase durability
	Dropping the controller can cause pins to recess out of the connector block, which can cause pump to stop		Heartware	90	Design for connection without pins, or more robust connection with larger prongs, implant a buffer battery so that patient has time to replace controller
	Exposure to water or other fluids		Not specified	54	Connectors must be splash proof with waterproof seal
	Failure due to inappropriate connection while connector pins are in a misaligned position		Not specified	54	Design for connection without pins, or more robust connection with larger prongs, use guides with longer lead-in, shaped connectors (not round) and/or magnetic assistance
	Failure of the protective O-ring at the power port or the monitor port of the controller due to repeated stress		Not specified	54	Increase durability and O-ring lifetime
	Faulty connectors (including the connectors for the driveline), may result in controller failure		Not specified	54	Increase durability, ensure protocol is implemented so that working cable replacement is available at all times
	Jamming during plug insertion		Not specified	35	Ensure guides slide smoothly with adequate tolerances, magnetic assistance, remove pins
	Lock and release-style significantly reduces unintentional disconnection of driveline but could cause exit site injury (e.g. if the carry bag is dropped) vs. unlocked driveline connectors that decouple at a certain force reduce exit site trauma/infection but also causes pump to immediately stop upon unintentional disconnection		Heartmate II	82,83	Use a Design Innovation approach to determine user preferences from the following: (1) Design a system with both controller and implanted buffer batteries so that power is not lost with cables that disconnect at a certain force and/or (2) insert helical spring-like segments83 or retractable component in driveline design and/or (3) provide a connector system with guard or two-step disconnection process to reduce accidental disconnection by force only
	Making sure the connections are right; Clear “snap-in” connector feature desired by patients	Adjustment	Not specified	21,35	Obvious, audible & tactile “click-in” feature, snap-in feature, with magnetic assistance
	Matching arrows that line up at the respective end of the cable and its connector pair desired		Not specified	34	Implement matching arrows, along with guides, color-coding and matching shapes for connection system—so there is no way to get it wrong
	Must be checked for damage, including Routine Outpatient Evaluation: Visual inspection of connectors as they are fragile and easily damaged, visible wear can indicate future problems		Not specified	49,19,23	Simplify or standardize inspection protocol, simplify training with digital learning or training app
	Unintentional disconnection of either the VAD, cables, or both power supplies e.g. during changing clothes, in the bathroom, or during driving; may lead to pump stop	Feeling unsafe, Fear	Not specified, Heartware HVAD, HeartMate II, DuraHeart	8,35,38,82,83	Use a Design Innovation approach to determine user preferences from the following: (1) Design a system with both controller and implanted buffer batteries so that power is not lost with cables that disconnect at a certain force and/or (2) insert helical spring-like segments83 or retractable component in driveline design and/or (3) provide a connector system with guard or two-step disconnection process to reduce accidental disconnection by force only
Controller	Cell battery in the controller failure		Heartmate II	54	Ensure protocol is implemented so that working cell battery replacement is available at all times
	Controller limits comfortable sleeping positions		Not specified	33	Adopt postauricular percutaneous power delivery technology that avoids abdominal area and removes obstruction to comfortable sleeping position, pillow-like padded bag for sleeping with33 for batteries and controller connected to abdominal driveline
	Difficult to find comfortable clothing that conceals the controller		Not specified	21	Design wearable options for patients who wish to wear system both underneath clothing e.g. in a vest, t-shirt, or wrap, or discreet carry system on top of clothing e.g. in a bag or belt
	Dropping controller causing damage (e.g. dropping on the floor can cause electrical fault in pump or implanted driveline, requiring pump replacement		Heartware	54,90	Design controller with impact-resistant drop-proof housing, or soft impact-protecting material e.g. D3O padding or additional casing of hard parts
	Exposure to water or biological fluids		Not specified	54	Make resistant to water and biological fluids
	Faults, defects and failure, requiring controller replacement		Not specified	54,82	Increase reliability,
	Heat discharge problematic as controllers are made from synthetic materials with poor thermal conductivity, overheating of the controller (partially due to the protective bag)		Not specified	35,83	Use newer heat dispersing materials for controller housing, ensure adequate ventilation around controller, or return to using superior magnesium housing material83
	Monitoring, maintaining and managing device function	Confronting, Anxiety, Fear, Stress	Not specified	21,62,49,4,19,23,79	Friendly user interface with intuitive processes, digital training program or virtual assistant
	More control elements and other forms of displaying an error desired		Thoratec, Heartware	34,90	Allow for different layers of information to be displayed at different times i.e. essential device and peripherals information for displaying ambient status or critical emergency instructions, more detailed information upon request for specific diagnostics (e.g. pump parameters), make simplified clinical menu available via controller
	Must be checked for damage, including Routine Outpatient Evaluation: Visual inspection of controller for physical damage (e.g. broken housing)		Not specified	49,23	Simplify or standardize inspection protocol, simplify training with digital learning or training app
	Patients with the HeartMate II only have access to view parameters including speed, flow, wattage, and alarms data when the system display and power base unit are connected		Heartmate II	68	Make speed, flow, wattage, and alarms data visible on controller when requested, show the state of device with an ambient display solution that’s as stress-free as using a watch or wall clock for checking the time—that can be hidden if necessary, e.g. at night
	Pressing a wrong button on the controller	Fear	Not specified	13,21	Friendly user interface with intuitive processes, training program, or AI virtual assistant
	Software issue or abnormality		Not specified	54	Increase software reliability
	Users with limited manual dexterity due to e.g. osteoarthritis, may find controller changes challenging	Adaptation	Not specified	60,83	Implement usability and human-factors to design simpler, easier controller exchange procedure
	Women desire a reduction of size and weight of controllers, too large and heavy for women		Not specified	33,82,83	Reduce size and weight of controller
Driveline	Afraid that the driveline would be pulled out from abdomen during sexual intimacy, causing injury	Fear, Concern, Vigilance, Worry	Not specified	66,49,19	Immobilize the driveline to prevent trauma & injury, with a suitable driveline management system for more vigorous physical activity, adopt postauricular percutaneous power delivery technology, remove the percutaneous driveline entirely using TETS technology
	Anchor or fixing system required: Driveline must be secured, immobilized and protected from trauma, because movement will disrupt the delicate tissue in-growth in the velour lining of the driveline, resulting in much higher infection risk		Not specified	87,95,49,7,19,29	Adopt postauricular percutaneous power delivery technology which removes need for driveline anchor
	Avoid kinking, bending, twisting or tugging driveline when putting on heavy clothing, coats or jackets		Not specified	49	Adopt postauricular percutaneous power delivery technology that avoids abdominal area and removes interference with clothing, ensure sufficient strain-relief, increase flexibility and robustness including kink-resistance for example with a protective coil within the outer sheath, implantable buffer battery in patient to give time in case of driveline damage
	Cleaning around the driveline	Care-dependency	Not specified	49,8	Adopt postauricular percutaneous power delivery technology, remove the percutaneous driveline entirely using TETS technology, improve infection control procedures and self-care adherence that may be performed by patient themselves if preferred
	Damage to the driveline bend relief (located at the controller end)		Thoratec	83	Modular cable connection near the driveline exit site (as with HeartMate III and Jarvik 2000 postauricular cables)
	Difficult to find comfortable clothing that conceals the driveline		Not specified	21	Driveline cover, design a method for patients to modify their choice of clothing to accommodate and conceal abdominal driveline, adopt postauricular percutaneous power delivery technology that avoids abdominal area and removes interference with clothing
	Difficulties finding comfortable clothes for special occasions, that concealed the external components of the VAD system		Not specified	63	Design a method for patients to modify their choice of clothing to accommodate and conceal abdominal driveline, adopt postauricular percutaneous power delivery technology that avoids abdominal area and removes interference with clothing
	Difficulties finding practical, comfortable and natural-looking clothing (that accommodates rather than accentuates the VAD equipment)	Coping	Not specified	63	Adopt postauricular percutaneous power delivery technology, more ergonomic and discreet VAD equipment and carrying system that fits seamlessly with natural-looking clothing. Design clothing patterns for VAD patients
	Difficulties selecting and wearing clothes to protect the integrity of the VAD system and the patient’s perceived body image		Not specified	63	Adopt postauricular percutaneous power delivery technology paired with smaller, lighter external components
	Discomfort associated with the exit site of the driveline		Not specified	21,49	Adopt postauricular percutaneous power delivery technology, remove the percutaneous driveline entirely using TETS technology
	Driveline as a tube with 4 small wires inside looks fragile—damage may require major operation and implant replacement	Concern, Scary, Uncertainty	Not specified	8	Design the driveline to be robust without compromising flexibility and function, reduce number or diameter of wires required within the driveline to power device, design for driveline replacement without device replacement, modular driveline
	Driveline exposed if external components are carried in a conventional backpack, increasing risk of infections		Not specified	71	Design a washable driveline cover
	Driveline forms a highway between outside world and bloodstream		Not specified	88	Postauricular percutaneous power delivery technology has a lower rate of infection due to better tissue integration,84,96 remove the percutaneous driveline entirely using TETS technology
	Driveline fracture, damage, or breakage causing life-threatening pump failure, requiring pump replacement or urgent heart transplantation, or death		Heartmate II, HVAD, not specified	9,54,83,85	Separate cable reliability from pump reliability with a sealed modular system (as with HeartMate III), adopt postauricular percutaneous power delivery technology
	Driveline limits comfortable sleeping positions, disturbed sleep due to new sleeping position on the opposite site to equipment, and underlying discomfort from the driveline, inability to lie on the side of driveline exit site, preferred sleeping positions include lying on the side (propped with a pillow) opposite to the driveline and lying on the back, inability to lie on the side of driveline exit site		Not specified	21,33,49,83	Adopt postauricular percutaneous power delivery technology that avoids abdominal area and removes obstruction to comfortable sleeping position
	Driveline limits movement, due to pulling		Not specified	33	Ensure sufficient strain relief
	Driveline rubbing against parts of the body		Not specified	83	Adopt postauricular percutaneous power delivery technology that avoids abdominal area and eliminates irritation to the skin
	Electrical failure		Not specified	54	Increase durability and reliability
	Females can’t wear one-piece dresses, driveline comes out from left lower quadrant of the abdomen to external equipment		Not specified	21	Design a dress with a feature that allows patient to easily pass driveline and other components through, design a method for patients to modify their choice of clothing to accommodate abdominal driveline, adopt postauricular percutaneous power delivery technology that avoids abdominal area and removes obstruction to clothing
	Finding a high-rise toilet seat to promote comfort and keep the driveline stable	Adjustment, Unexpected, Stressful	Not specified	62	Adopt postauricular percutaneous power delivery technology, improve stability and immobilize the driveline to prevent trauma & injury
	Gets in the way during sexual intimacy, position of the driveline during intercourse	Self-conscious, Concern, Encumbered, Deeper intimacy, Adjustment	Not specified	33,60,66,49,4,19	Adopt postauricular percutaneous power delivery technology, design a suitable driveline management system for more vigorous physical activity
	Having a driveline exit through the skin causing change in self-image	Adaptation	Not specified	19	Acceptance therapy delivered via digital wellbeing tool/app, remove the percutaneous driveline entirely using TETS technology
	Holes in external sheath/insulation of driveline caused by constant mechanical stress or rubbing on clothes—able to be fixed with tape or self-fusing tape		Not specified	71,83	Increase abrasion resistance and durability, modular driveline so that worn segments can be replaced
	Infection: exit site infection and device-related infection (relating to the percutaneous lead), which often leads to increased readmission rates, prolonged hospital stays, increased healthcare costs, pump infection, increased risk of thrombosis or sepsis and consequently may result in removal from the transplant active waiting list, VAD removal, and death	Fear, Distrust, Worry, Caution, Helplessness, Irony, Distress, Difficulty coping, Exposed, Vulnerable, Unsafe, Concern	Not specified	57,71,85,95,49,4,7,8,83,91,94	Adopt postauricular percutaneous power delivery technology, remove the percutaneous driveline entirely using TETS technology, improve and simplify infection control procedures and self-care adherence, chemical or physical infection barriers, accelerated skin healing, coatings or covers, immobilize the driveline to prevent trauma & injury
	LVAD partners expressed fear of making driveline-related mistakes	Fear	Not specified	13	Improve and simplify infection control procedures and self-care adherence, training program or virtual assistant
	Must be visually inspected daily		Not specified	49	Simplify or standardize inspection protocol, simplify training with digital learning or training app
	Need to avoid contact sports or strenuous activities that could damage the driveline site		Not specified	49,19,83	Acceptance therapy delivered via digital wellbeing app (Removing or moving driveline will not resolve this as implanted components could also be damaged by these activities)
	Need to integrate the VAD so that it feels like a natural part of body and body image		Not specified	91	Prioritize good industrial design to integrate VAD in a more “natural”, seamless way with the body
	Pants need to have a waistband lower than the natural waistline and not tight fitting to accommodate driveline		Not specified	63	Adopt postauricular percutaneous power delivery technology that avoids abdominal area and allows patient to wear normal clothes
	Physical limitations		Not specified	21,87	Adopt postauricular percutaneous power delivery technology, remove the percutaneous driveline entirely using TETS technology
	Preferred sleeping positions include lying on the side (propped with a pillow) opposite to the driveline and lying on the back, inability to lie on the side of driveline exit site		Not specified	21,49	Adopt postauricular percutaneous power delivery technology that avoids abdominal area and removes obstruction to comfortable sleeping position
	Rare intentional cutting or disconnection of driveline to discontinue VAD support		Not specified	19,54	Mental health support for at-risk patients, digital wellbeing tool/app
	Rare reports exist of patients cutting the integral pump driveline with successful repair		Not specified	54	Modular driveline to aid replacement of damaged segment
	Routine Outpatient Evaluation involves visual and tactile driveline inspection for breaches in the silicone sleeve or insulation, plus x-ray (if needed to see internal wires)		Not specified	23	Simplify or standardize inspection protocol, simplify training with digital learning or training app
	Skin irritation resulting from friction from the abdominal binder used to immobilize the driveline and to promote wound healing (wearing a camisole under abdominal binder may prevent driveline from rubbing)		Not specified	63	Use softer, more skin-friendly materials for VAD wearable components and accessories, adopt postauricular percutaneous power delivery technology to prevent interference with clothing and sensitive skin
	Skin irritation resulting from friction from the driveline		Not specified	63	Adopt postauricular percutaneous power delivery technology that avoids abdominal area and thus eliminates irritation
	Stretching, bending or twisting beyond the limits of robustness causing damage to internal ground shielding and inner power and controller leads, failure because of fracture of the internal ground shielding in the integral pump driveline resulting in pump stoppage and/or device replacement—“Short to shield”		Heartmate II	54	Increase flexibility and robustness including kink-resistance for example with a protective coil within the outer sheath, implant buffer battery in patient to give time in case of driveline failure
	Tape used to repair driveline not designed for direct skin contact, could cause irritation		Not specified	83	Modular cable connection near the driveline exit site (as with HeartMate III and Jarvik 2000 postauricular cables)
	Unintentional damage e.g. during household/environmental accidents, or by coming in contact with sharp object		Not specified	54	Increase robustness and durability, including crush resistance by using e.g. Kevlar thread
Driveline dressing	Caregivers must have materials ready for dressing changes		Not specified	79	Digital training tool/app to promote habit forming around driveline hygiene, subscription and delivery service for dressing materials
	Changing the dressing, afraid of breaking sterile technique with dressing change	Flustered, Nervous, Nerve-wracking, Care-dependency, Maintaining independence, Sick, Disabled, Fear	Not specified	4,7,8,13,21,62,64,71,75,86,95	Improve and simplify infection control procedures and self-care adherence, training program or virtual assistant, adopt postauricular percutaneous power delivery technology to remove need for dressing
	Dressing rubbing against parts of the body		Not specified	83	Adopt postauricular percutaneous power delivery technology to prevent interference between dressing and sensitive skin
	Exit site wound management, according to protocol, gentle to avoid tissue trauma		Not specified	49,19,23	Postauricular percutaneous power delivery technology has better tissue integration,84,96 thus once wound is healed, no longer needs dressing48
	Increased frequency of dressing changes and more stringent immobilization during infection episodes		Not specified	49	Ensure best practice hygiene protocol is implemented, digital training tool/app to promote habit forming around driveline hygiene
	Learning methods for dressing, nursing staff require training for changing the dressing		Not specified	4,19	Ensure best practice hygiene protocol is implemented, digital training tool/app to promote habit forming around driveline hygiene
	Regular hand-washing for those who handle the dressing		Not specified	49,19	Ensure best practice hygiene protocol is implemented, digital training tool/app to promote habit forming around driveline hygiene and hand washing
	Sterile dressing procedure still required even after wound has healed, to protect against infection and minor injury		Not specified	29	Postauricular percutaneous power delivery technology has better tissue integration,84,96 thus once wound is healed, no longer needs dressing48
Holster/Vest/Harness	Batteries swing in the holsters on either side of torso		Not specified	33	Make holsters adjustable or multi-size
	Excess webbing strap dangles out		Not specified	33	Add simple elastic loop to hold excess webbing, design for closed adjustment with no excess strap
	Extra spandex layers needed to keep holster from bouncing when running for exercise		Not specified	33	Design an exercise-specific carry solution
	Hip-based design an improvement		Not specified	33	Distribute weight onto hips
	Ill-fitting on women as designed to fit the male torso	Frustration	Not specified	33	Design a holster/vest to fit women’s bodies
	Need to alternate between holster vest and modular belt to alleviate skin irritation from driveline and abdominal binder		Not specified	63	Adopt postauricular percutaneous power delivery technology that avoids abdominal area and eliminates abdominal binder, thus allowing more freedom to wear holster or vest over or under clothing as preferred
	No chest strap to secure		Not specified	33	Add securing strap if needed or other securing solution
	Patients make modifications as provided holster/vest doesn’t meet needs		Not specified	33	Research patient modifications and determine if patient hacks can be incorporated into a design that fits the needs of various users
	Pressure and soreness		Not specified	21	Determine location and cause of pressure and soreness
	Tightening webbing strap does not stabilize batteries		Not specified	33	Provide adequate stabilizing solution
	Unclear how it should be worn		Not specified	33	Make putting on and taking off as intuitive as possible, with e.g. textured tabs, logical design
	Vest provides little cushioning from the batteries especially for thin patients		Not specified	63	Incorporate padded sections e.g. foam or spacer fabric, design components with soft padded shell or gel exterior on patient-facing surfaces and edges
	Vests to hold batteries provided by the manufacturer make the neck/shoulders sore		Not specified	63	Reduce weight of batteries and redesign vest for optimal weight distribution
	Weight of heavy equipment causes digging into shoulders		Not specified	33	Reduce weight of all components, add padding or shaping to optimize weight distribution
	Weight of the batteries located at the bottom of the vest pull down on neck		Not specified	63	Redesign vest for optimal weight distribution
Modular Belt/Waist Bag	Directly in the way of food or drink spillage		Not specified	33	Make washable or wipe-clean surface
	Hard to access controller to disable alarm		Not specified	33	Redesign for quick access and troubleshooting
	Interacts with the abdominal binder and irritates the skin requiring wearing a camisole or longer shirt in between		Not specified	63	Use softer, more skin-friendly materials for VAD wearable components and accessories, adopt postauricular percutaneous power delivery technology to prevent interaction with clothing and sensitive skin
	Need to alternate between modular belt and holster vest to alleviate skin irritation from driveline and abdominal binder		Not specified	63	Adopt postauricular percutaneous power delivery technology that avoids abdominal area and eliminates abdominal binder, thus allowing more freedom to wear holster or vest over or under clothing as preferred
	Pants need to have a loose-fitting elasticated waistband lower than the natural waistline so that they can be easily pulled on and off to use the toilet		Not specified	63	Adopt postauricular percutaneous power delivery technology that avoids abdominal area and removes interference with clothing, allowing patient to wear normal clothing of their own preference
	Straps dig into back and cause shirt to ride up	Embarrassment	Not specified	33	Redesign waist bag to prevent clothing from riding up
	Velcro difficult to open quickly		Not specified	33	Add a tab loop or quick-release feature
Power supply	Being plugged into the wall	Freaked out	Not specified	8	Hide the standard electrical power cable behind the power base unit, with a smaller cord to the controller, optimize battery capacity so being plugged into the wall is for emergencies only, explore alternative renewable power options
	Daily morning routine of disconnecting from a 15-foot power cord to connect to a 12-hour battery pack, using proper procedures	Awkward, Dependency, Vulnerability	Not specified	95,49,8	Simplify procedure for switching from battery to mains and vice-versa, make intuitive and seamless
	Defective		Not specified	82	Increase reliability
	Device may fail acutely due to electrical or power issues		Not specified	88	Implanted buffer battery with sufficient charge to allow patient to access nearest hospital
	If a family with financial issues was unable to pay their electric bill and the electricity was cut off, the patient would be unable to plug in the device and charge batteries, with dire consequence		Not specified	75	Determine financial and environmental factors as part of a social support plan as this can impact treatment
	Maintaining adequate constant power supply via batteries or being in close proximity to a mains electricity, otherwise pump may stop with serious consequences	Boundedness, Being stuck, Dependence	Not specified	49,19,86	Increase battery capacity and durability, explore alternative renewable power options, implanted back-up buffer battery and controller buffer battery to give patient extra time if a power mistake is made
	Major changes to bedtime routine to accommodate safety procedures—including switching from battery to tethered mains power via the PBU, ensure adequate charge of battery backup, and that an emergency power pack is charged and available in case of power failure		Not specified	21,49	Simplify bedtime routine and procedure for switching from battery to mains and vice-versa, make intuitive and seamless, make power supply backup habits stick by training with user-friendly checklist on digital app
	Managing power supply by either changing from mains power to batteries or vice versa according to preference, prior to sexual intimacy (generally, men preferred the flexibility of batteries, women felt more comfortable on mains power)	Anxiety, Awkward, Encumbered, Deeper intimacy, Adjustment	Not specified	4,66	Simplify procedure for switching from battery to mains and vice-versa, make intuitive and seamless
	Need for an extracorporeal energy supply		Not specified	49	Design a backup battery procedure that’s easy to make habitual, explore alternative renewable power options
	Power configurations have the ability to tolerate just one single fault in power handling—not more		Heartware HVAD, HeartMate II and HeartMate III	83	Design for two faults in power handling—discharge batteries consecutively not in parallel, ensure controller has a buffer battery and power base unit for AC operation has a backup battery, consider implanted buffer battery
	Power outage	Fear	Not specified	8	Design a backup battery procedure that’s easy to make habitual, explore alternative renewable power options
	To prepare for prolonged power disruption, patients must always keep the backup controller, charged spare batteries, battery clips with cables, and emergency ID card with them constantly		Not specified	49	Ensure protocol is implemented so that working component back-ups and replacements are available and ready at all times, implanted buffer battery with sufficient charge to allow patient to access nearest hospital
Shower bag	Elastic and Velcro arrangement for securing the controller and batteries difficult to work out		Not specified	33	Make intuitive e.g. with colored grab-tags
	Feels like showering with a briefcase that can’t be put down		Not specified	33	Simplify bathing procedure through user-centered design of procedure and accessories that may allow a patient to shower independently, adopt postauricular percutaneous power delivery technology that enables showering
	Hard to dry oneself, must hold equipment while holding towel with one hand		Not specified	33	Simplify bathing procedure through user-centered design of procedure and accessories that may allow a patient to shower independently, adopt postauricular percutaneous power delivery technology that enables showering
	Hard to tell if water is entering bag or device through hole for driveline		Not specified	33	Provide clear window to bag interior
	Manufacturer-provided waterproof shower bag cumbersome, too large and not practical		Not specified	33	Reduce size and bulk of bag
	Required a lot of force to push batteries into elastic bands		Not specified	33	Reduce elastic tightness
	Unclear which order to place components		Not specified	33	Printed diagram on bag interior with placement order 1,2,3 etc
	Velcro hard to pull undone		Not specified	33	Reduce Velcro force
Visual interface	A separate ‘disconnected’ symbol and a respective ‘reconnected’ light that would indicate a successful reconnection immediately after a previous driveline disconnect desired		Not specified	34	Design and test with users to ensure usability is improved
	Alphanumeric displays are preferred and provide more/better information than indicator lights alone		Not specified	34	Improve graphical user interface (GUI) by involving user interface/user experience (UI/UX) designer and considering product semiotics and semantics
	Backlight insufficiently bright		Not specified	82,83	Allow the ability to increase and decrease screen brightness
	Difficulties reading messages or codes easily, for example regarding battery status		Not specified	35,82	Use bigger screen and larger font
	Display reading “not connected” when one of 2 cables is disconnected from controller, causing confusion, pump stoppage, and inability to resolve error without emergency services		HeartMate II	90	Use clear language, unambiguous information specific to individual parts e.g. “cable connector to battery 1” and prioritize user interface design to reduce risk of misinterpretation and carefully consider product semiotics and semantics
	For devices with text displays, font size too small and text not clearly visible, especially for older persons		Not specified	35,82,83	Use bigger screen and larger font
	Information structured as advice (e.g. “reconnect the blue cable with the blue connector”) may be more easily understood than status information (e.g. “error: driveline disconnect”), unless there are multiple possible reasons for an error to occur		Not specified	34	Design and test with users to ensure usability and understanding is effective with linguistic and semantic improvements
	Large display preferred, while still achieving small and lightweight peripherals		Not specified	83	Specify bigger screen/large display
	Misinterpreting LVAD parameters or messages, confusing display	Fear	Not specified	13,21,35,90	Prioritize user interface design to reduce risk of misinterpretation and carefully consider product semiotics and semantics. The article “Importance of Linguistic Details in Alarm Messages of Ventricular Assist Devices” by Schima et al.81 addresses this important issue.81
	Monitor/display handling issues		Not specified	82	Improve usability by involving user interface/user experience (UI/UX) designer
	Need for different layers of information to be displayed at different times i.e. essential device and peripherals information for displaying ambient status or critical emergency instructions, more detailed information upon request for specific diagnostics (e.g. pump parameters)		Not specified	83	Allow for different layers of information to be displayed at different times i.e. essential device and peripherals information for displaying ambient status or critical emergency instructions, more detailed information upon request for specific diagnostics (e.g. pump parameters)
	Older patients had more problems with visual controller interface		Not specified	83	Use bigger screen, larger font and ability to increase screen brightness, plus optional audible cues
	Pictograms (HMII) and text displays (HVAD) are preferable to the display of alarm codes (Incor)		Incor	82	Improve usability by involving user interface/user experience (UI/UX) designer and considering product semiotics and semantics
	Poor design can cause unintended errors, difficulty in learning and using	Dissatisfaction	Not specified	83	Prioritize user interface design to reduce risk of misinterpretation and carefully consider product semiotics and semantics
	Screen too bright at night		Not specified	35	Allow ability to turn down or turn off screen at night
	User must be able to recognize the signs of pump malfunction by interpreting information on the controller screen (e.g. low flow, high power)		Not specified	49	Prioritize user interface design to reduce risk of misinterpretation and carefully consider product semiotics and semantics
Whole system / Not Specified	Ability to execute skills required to maintain the functionality of the device and troubleshoot the system when technical problems occur	Doubt, Distress, Anxiety, Fear, Stress	Not specified	21,49,91	Design for intuitive, confident use of the system, training program or virtual assistant
	Alteration of body image; change in self-image due to carrying external components; Physical appearance of the machine causing change in self-image	Distress, Adaptation, Insecurity, Concern, Fear of rejection	Not specified	4,19,29,66	Digital learning tool or training app to help with acceptance therapy, holistic wellbeing; Improved industrial design of VAD for discreet wear—less like a serious medical device and more like a friendly wearable fitness device, design the VAD like it is an integral part of the human body, as opposed to a machine adhered to the edges of it
	Aspects of device use may be inconsistent with the user’s expectations or intuition		Not specified	54	Design the user experience to harmonize with the user’s expectations or intuition
	Avoid exposure to electrostatic discharge e.g. from computer or TV monitors		Not specified	83	Computers, TVs and mobile devices are ingrained in daily life—design of VAD system must be compatible with common consumer products in everyday living
	Avoid prolonged exposure to cold or heat		Not specified	49	Design device to be compatible with extreme environments found in warmer or colder climates e.g. Australia or Canada
	Being away from clinicians and caregivers	Fear	Not specified	8	Better connectivity with both clinicians and caregivers
	Caregiving role and routine (including bathing, help with getting dressed and bedtime routine, sterile dressing changes, monitoring device function, managing equipment, day-to-day care, handle battery issues and docking system, ensuring adequate constant power supply, 24-hour supervision), and family support	Time, Discomfort, Overwhelmed, Adjustment, Adaptation, Care dependency	Not specified	60,62,49,8,19,79	Simplify bathing procedure through user-centered design of procedure and accessories that may allow a patient to shower independently, adopt postauricular percutaneous power delivery technology that enables showering, design an ambient solution for monitoring device function, respite care for caregivers
	Careless or clumsy use of system components		Not specified	35,90	Make the use of the system and procedures intuitive and seamless especially in times of urgency
	Certainty of death (whether by interrupted power supply, driveline infection, mechanical malfunction, or turning the device off, etc.)	Concern	Not specified	8,83	Better human factors and usability to reduce risk of death, digital training tool or app to help with acceptance therapy, preparedness planning and holistic wellbeing
	Complications	Worry	Not specified	29	Improve device usability and reliability
	Components are conspicuous to the general public during daily life		Not specified	83	Design for discretion of wearability
	Confidence in safe use of the system decreased significantly with age, from 80% at age 20–30 years to 33% at 70–80 years	Lack of confidence	Not specified	82,83	Design for the optimum safe usability for a person aged 70-80, not a 20-30 year old. Different wearable equipment models to suit different users
	Confusing labels, better, clearer component labelling desired		Not specified	34,83,90	Standardize nomenclature of labels, make clearer
	Constantly checking that the VAD system is always working	Stressful, Fear, Worry	Not specified	64	Design an ambient device status solution that’s as stress-free as using a watch or wall clock for checking the time
	Cumbersome, bulky equipment (both internal and external components)		Not specified	33,83,86	Make components smaller, lighter, slimmer or flexible
	Currently no VAD components made that take the curvature of the female body or optimal distribution of weight for females into account		Not specified	33	Design components with 3-dimensional curvature (not just curvature on a single plane) to take into account female ergonomics, create flexible components or components with a soft foam or gel backing that conform to individual body curvature, design components for optimal weight distribution
	Demands associated with use of the device exceed the user’s capabilities		Not specified	54	Design for users with an assumption that they are tired, overwhelmed, with physical and mental impairment, which will improve usability for all
	Device helps patients survive, but is also unpredictable and not truly their own	Foreign object, Dependence	Not specified	49	Improve usability, durability and reliability, digital training tool or app to help with acceptance therapy, preparedness planning and holistic wellbeing
	Difficulty readjusting the VAD components in public places: a chair is necessary for readjusting the cables, driveline, controller, and batteries after using restaurant or public toilet restrooms		Not specified	63	Design a carry system that can be worn multiple ways or adjusted easily over clothes, adopt postauricular percutaneous power delivery technology that avoids abdominal area and removes obstruction to clothing
	Driving: Some patients restricted in their agility to drive by device equipment, some patients instructed not to drive by clinician		Not specified	4,38	Design for components to be placed comfortably and appropriately when either travelling in a car or driving
	Emergency: Caregiver must prepare for emergency situations, responding to emergency situations, error-prone emergency procedures, emergency card too complex, needs clear labelling of instructions for VAD emergency procedures		Not specified, HeartMate II	34,62,49,4,64,79,83,90	Reduce complexity of emergency procedures, simplify training for emergency scenarios with digital learning or training app, user-friendly emergency scenario preparedness checklist and periodic scenario-based skills-test
	Emergency: Standardisation of emergency protocols between different VAD manufacturers desired		Not specified	34,83	Investigate feasibility of standardized best-practice emergency protocols
	Equipment difficult to hide		Not specified	71	Reduces size and profile of all components
	Exercising: Inconvenient when exercising, accessories not designed to match activity level and limit movement as well as cause stability issues, conventional backpack worn on front at the gym, so patient could do sit-ups		Not specified	33	Design an exercise-specific carrying solution, reduce size and weight of components, design a carrying solution specific for more rigorous activity levels
	External equipment must be placed to prevent damage during mobility		Not specified	95	Design a carrying system that reduces susceptibility to damage
	Forgetting extra batteries or other necessary accessories	Fear	Not specified	8	Simple reminder solution for bringing extra components e.g. carry bag with recesses, special pockets or “shadow board” design to be filled by needed components daily
	Gender differences between male and female bodies not taken into consideration		Not specified	33	Design for female users—the benefit will be seen by all patients
	General confusion in how to handle the system		Not specified	83,90	Involve user experience designer from the early end of VAD product development process
	Get in the way of activities such as golf, exercise and being intimate		Not specified	33	Investigate different configurations of components and wearables for various activities, adopt postauricular percutaneous power delivery technology
	Getting used to the physical properties of the VAD	Adjustment	Not specified	21	Design the VAD like it is an integral part of the human body, as opposed to a machine adhered to the edges of it
	Heavy, weight of the complete system too high		Not specified	33,82,83	Prioritize weight reduction of system
	Joining of the body to a mechanical object—a machine becomes a part of the body	Foreign object	Not specified	8,29,86	Design the VAD like it is an integral part of the human body, as opposed to a machine adhered to the edges of it
	Lack of a heart rhythm	Distressing	Not specified	29	Introduce pulsatility (like HeartMate 3) with a natural rhythm to continuous flow devices, lighting on controller that gently pulses or fades in and out (rather than flashing) to indicate function, like an Apple computer on-light that appears to ‘breathe’
	Lack of robustness in normal patient lifestyle conditions, use environment may be harmful to the device		Not specified	54	Increase component and system robustness for actual, everyday use
	Learning complex device management and maintenance	Overwhelming, Concern, Scary, Anxiety, Fear, Stress	Not specified	49,4,64	Simplify training with digital learning tool or training app
	Learning to use supportive gear for wearing the device		Not specified	4	Make carry system intuitive
	Life-saving comes with trade-offs	Loss of autonomy, Powerlessness, Lack of freedom, Adjustment	Not specified	8	Design the VAD like it is an integral part of the human body, as opposed to a machine adhered to the edges of it
	Limitation: physical and structural, having a VAD prevents patient from doing certain things	Upset, Adaption, Annoyance, Awkward, Acceptance	Not specified	8,66,71,87	Design the VAD like it is an integral part of the human body, as opposed to a machine adhered to the edges of it, adopt postauricular percutaneous power delivery technology that enables swimming and showering, accessory designs that allow for certain currently-forbidden activities, e.g. waterproof suit and device cover for swimming, leakproof/waterproof immersion cover for taking baths or boating, external component padding to protect hard components or body from impact
	Living with a VAD	Difficulty coping, Exposed, Vulnerable	Not specified	4	Digital learning tool or training app to help with acceptance therapy, holistic wellbeing
	Male patients may show keen interest in the technical aspects of their device		Not specified	29	Make non-clinical technical aspects of the device available to those who wish to know or learn about it
	Malfunction	Worry, Difficulty coping, Exposed, Vulnerable, Unsafe	Not specified	4,83,91	Improve device usability and reliability
	Monitoring device during sex, watching the flow and rate of the VAD, afraid of too much exertion	Afraid	Not specified	79	Show the flow and speed of VAD with an ambient status solution that’s as stress-free as using a watch or wall clock for checking the time
	More difficult than caring for a transplant		Not specified	75	Design for intuitive use and seamless integration into normal daily activities, like a consumer product
	Morning-time routine, getting up with the equipment	Time-burden, Patience, Living, Being alive	Not specified	4,21	Simplify morning procedure through user-centered design
	Necessity of complying to a complex technical regimen—responding under pressure to warning signals by changing batteries or transition from battery to power base unit mode	Psychological distress	Not specified	57	Improve and simplify device procedures, design a power management procedure that’s easy to make habitual, training program or virtual assistant
	Need for a more formal solution to wearing a VAD in a corporate environment (for a businessman)		Not specified	33	Design an inner-bag to be carried with patient-preferred bag, or a system to carry components more discretely against body
	Need for a solution to allow women to dress up in eveningwear		Not specified	33	Adopt postauricular percutaneous power delivery technology so that abdomen area is not inconvenienced and so that driveline does not obstruct clothing, design a method for patients to modify their choice of clothing to accommodate abdominal driveline
	Need for a solution to allow women to wear form-fitting clothing		Not specified	33	Adopt postauricular percutaneous power delivery technology so that abdomen area is not inconvenienced and so that driveline does not obstruct clothing, design a method for patients to modify their choice of clothing to accommodate abdominal driveline
	Need to carry 2 controllers and 2 batteries (for backup)		Not specified	71	Expandable carry bag section for spare components, or 2-bag system; for day trips, a simple reminder solution for bringing extra components e.g. carry bag with recesses, special pockets or “shadow board” design to be filled by needed components daily
	Night-time routine, going to bed with the equipment	Time-burden, Adjustment, Struggle, Patience, Living, Being alive	Not specified	4,21,62	Simplify bedtime procedure through user-centered design of procedure and sleep accessories
	Nursing staff require training for handling VAD systems/components and identifying malfunctioning or complications		Not specified	19	Simplify training with digital learning or training app
	Out in public, the VAD attracts attention, people often stare and ask questions	Embarrassed	Not specified	4	Design for discretion of wearability
	Overcoming fear and anxiety to master self-care and safety behavior	Fear, Anxiety, Acceptance, Self-confidence	Not specified	21	Design a self-care procedure that’s easy to make habitual, improve and simplify self-care procedures to improve adherence, training program or virtual assistant
	Pain		Not specified	82	Research causes of pain in order to address specific issues
	Parts that rub on the body		Not specified	35,82,83,90	Design wearables so that interaction of parts with body does not cause rubbing
	Patients have holders for equipment custom-made to suit them		Not specified	33	Conduct design research to catalogue custom solutions and determine whether the ideas can be implemented in a manufacturer-supplied mass-produced holder
	Patients ignore advice to avoid activities such as boating		Not specified	4	Add a patient values assessment to tools that determine patient quality of life—as (especially for destination therapy patients) there may exist a risk vs. values trade-off where physical restrictions are deemed to make life not worth living
	Patients seeing own reflection in the mirror	Awe, Dismay, Mixed feelings, Overwhelmed, Doubtful, Amazed, Foreign object, Being alive	Not specified	21	Improved industrial design of VAD—less like a serious medical device and more like a friendly wearable fitness device
	Patients wish to discreetly carry the VAD accessories		Not specified	33	Design a discreet carry solution
	Physical activities forbidden that may result in damage to the device e.g. go-karting, paintballing, rugby, American football, rough play with children	Unfamiliar, Unhomelike, Nervous, Compromised, “New normal”, Loss	Not specified	86,87	Soft-shell or flexible components, or sufficient protective armor/padding for the device to be used in certain circumstances
	Physicality of the device and necessity of protecting it	Limited, Vulnerable, Dependence	Not specified	86,87	Soft-shell or flexible components, or sufficient protective armor/padding for the device to be used in certain circumstances
	Poor usability	Unsafe, Dissatisfaction	Not specified	90	Involve user experience designer from the early end of VAD product development process
	Problems with component contamination		Not specified	82	Make components easy to clean with no dust/dirt traps
	Regular hand-washing for those who handle the equipment		Not specified	49	Ensure best practice hygiene protocol is implemented, digital training tool/app to promote habit forming around hand washing and cleanliness
Routine Outpatient Evaluation involves a technical check, review of device function, and comprehensive visual inspection to exclude damage		Not specified	23	Simplify or standardize inspection protocol, simplify training with digital learning or training app
Securing and protecting the external components of the VAD (i.e. driveline and controller) for sexual intimacy (e.g. by using abdominal binders to prevent driveline pulling and trauma to the driveline)	Caution, Uncertainty, Careful, Adjustment, Concern, Vigilance, Awkward, Encumbered, Deeper intimacy, Adjustment	Not specified	4,66	Design a more ergonomic system and suitable driveline management solution with sufficient stabilizing for more vigorous physical activity, cord and cable management solution
Seeing, hearing and feeling the device for the first time	Shock		29	Industrial design with a friendly and simple aesthetic similar to a consumer product
Showering and hygiene: Cannot get wet—getting ready to shower can take 45 min, learning methods for bathing, change of bathing ritual—wearing a waterproof bag around neck, wrapping device with cling wrap, or taking sponge baths. Taking a shower with the external VAD components, with specific steps, precautions, and rituals to keep the dressing, batteries and controller dry	Procrastination, Lament, Confronting, Challenging, Frightening, Care-dependency	Not specified	21,33,63,49,4	Adopt postauricular percutaneous power delivery technology that enables uncomplicated showering, simplify bathing procedure through user-centered design of procedure and bathing accessories, simplify bathing procedure through user-centered design of procedure and bathing accessories
Some manufacturers advise to keep cell phones a minimum of 0.5 m (20 in.) away from the controller		Heartware HVAD	83	Computers, TVs and mobile devices are ingrained in daily life—design of VAD system must be compatible with common consumer products in everyday living
Starting intimate relationships with a new partner	Insecurity, Fear of rejection, Unattractive “turn off”	Not specified	66	Improved industrial design of VAD—less like a serious medical device and more like a friendly wearable fitness device
Taking more time to load and unload the VAD equipment and the patient in and out of cars	Unexpected, Adjustment, Stressful, Time-burden, Struggle	Not specified	62	Packing and travel solution for VAD equipment
Travel: A lot of hardware, so much ‘stuff’ to take when travelling, almost not worth it		Not specified	8	Smaller, lighter components with logical packing solution, design a more portable charger/power base unit solution and backup kit
Travel: Healthcare practitioner should be made aware of any travel via train, ship or airplane, additional security procedures when travelling		Not specified	49	App-based travel notification tool with database of VAD-aware hospitals and practitioners worldwide for shared care, design a more portable charger/power base unit solution and backup kit, smaller, lighter components with logical packing solution, packing and travel solution for VAD equipment
Use of fishing vests and waist bags instead of manufacturer-provided bag		Not specified	33	Design carrying solutions to suit lifestyle and comfort, more like a consumer product rather than a medical product
Used in inappropriate but foreseeable ways, without adequate controls on such actions		Not specified	54	Design affordances and controls into the user experience to discourage using the system in ways other than the intended use
Used in unexpected ways		Not specified	54	Design affordances and controls into the user experience to discourage using the system in ways other than the intended use
Using a conventional backpack to carry components, weight of equipment in backpack caused backache		Not specified	71	Reduce weight of all components, design inner-bag insert that balances weight
Vacuum equipment to remove dust		Not specified	49	Ensure cleaning protocol is explained in training, design for ease of cleaning and maintenance to avoid dust and dirt traps
VAD partners afraid of making device-related mistakes	Fear	Not specified	13	Improve and simplify device procedures, training program or virtual assistant
Vital component of a patient’s body and life, “part of you”	Acceptance, Adjustment	Not specified	21,66	Design the VAD like it is an integral part of the human body, as opposed to a machine adhered to the edges of it
Women may seek emotional acceptance by giving their device a personal nickname		Not specified	29	Industrial design of device to be like a friendly companion, not a hard machine
Women opt to carry equipment in their handbag or purse; uneven distribution of weight may cause discomfort or injury		Not specified	33	Design a more feminine carry solution rather than a “unisex” (i.e. casual masculine) aesthetic, design a shoulder bag that converts into a backpack

Appendix B: Quantitative studies

Year	Title	Authors	Location	No. Participants	Research Method/s	Key findings on VAD wearables
2009	Advanced Heart Failure Treated with Continuous-Flow Left Ventricular Assist Device	Slaughter et al.85	38 centers, USA	200 patients—134 continuous-flow devices (108 male, 26 female) and 66 pulsatile-flow devices (61 male, 5 female)	Randomized clinical trial—patients followed for 2 years or until death, transplantation or device explantation	10 of 13 pump replacements in a cohort of 133 patients was a result of breakage of the percutaneous lead, with one additional patient requiring device explantation for the same reason. Redesigning the modular components as well as the driveline may reduce this need for replacement
2010	Patient Satisfaction with the External Equipment of Implantable Left Ventricular Assist Devices	Meyer et al.68	Hannover, Germany	27 patients—HVAD (10 male), Heartmate II (14 male, 3 female)	9-question questionnaire for patient satisfaction of external components of VAD, and SF-36 for health-related QoL assessment	HVAD patients were dissatisfied with the length of the driveline (62 cm), but this was upgraded in 2010. Heartmate patients were dissatisfied with the volume of the battery charger/power base unit which caused limitations. HVAD patients were able to view pump parameters including speed, flow, wattage and alarms on the controller display at any time, but Heartmate II patients could only access this data when the system display, and power base unit were connected. Heartmate II patients also had to mark batteries after every exchange, whereas the HVAD shows the charge level of a battery at all times, hindering the possibility of exchanging a full battery with an empty one
2012	A multi-modal intervention in management of left ventricular assist device outpatients: dietary counselling, controlled exercise and psychosocial support	Kugler et al.57	Hannover, Germany	70 patients—34 intervention group (85.4% male), 36 control group (87.5% male)	Non-randomized intervention study, tested at 6 weeks (baseline), and at 6, 12 and 18 months while being on VAD support	According to Raymond et al.77 there is an association between driveline exit site infections and obesity. When compared to those without driveline exit site infections, VAD recipients who developed infections had a significantly higher BMI. Complying to a complex technical regime including responding to alarm signals by transitioning from battery to powerbase unit or changing batteries may contribute to psychological distress.77
2014	Usability of ventricular assist devices in daily experience: a multicenter study	Schima et al.82	4 centers (Bad Oeynhausen, Berlin, and Hannover, Germany; Vienna, Austria)	279 patients, then 73 patients for follow-up study	352 questionnaires (279 first inquiries + 73 s inquiries, recorded 6 months later), with Kansas City Cardiomyopathy Questionnaire (KCCQ) and WHO State of Health Index	Problems include unintentional dropping of the transportation bag, unintentional disconnection of cables to either the VAD or power supply sometimes resulting in pump stop (this was higher in the older cohort and female patients), disconnection during a change of clothes, wear discomfort of the bag (especially painful shoulder strap), heavy weight of the system, defective external components e.g. controller faults, handling of alarms, and having a confident fail-safe action in emergency situations. Elderly participants had more problems with the visual controller interface, including readability and backlighting. Heartmate II—GoGear has a 5 h mean battery discharge time (this, or more, was considered ideal)
2015	A comparison of the health status and psychological distress of partners of patients with a left ventricular assist device vs. an implantable cardioverter defibrillator: A preliminary study	Brouwers et al.13	Utrecht and Rotterdam, the Netherlands; Vancouver, Canada	33 LVAD partners (27% male) compared with 414 ICD partners (22% male)	Multi-center prospective observational study—standardized and validated set of questionnaires at baseline (when VAD patients were given training just prior to hospital discharge), and at 3- and 6-months follow-up	Caregivers of VAD patients are responsible for sterile dressing changes, monitoring device function, troubleshooting alarms and responding to emergencies. Caregivers fear making mistakes with the driveline or device (e.g. misinterpreting VAD parameters, pressing a wrong controller button, or breaking sterile technique while changing the exit site dressing)
2017	Left Ventricular Assist Device Malfunctions: It Is More Than Just the Pump	Kormos et al.54	Pittsburgh, PA, USA	213 patients—108 HM II axial flow device (16 female) and 105 HVAD centrifugal flow device (21 female)	Prospectively collected registry data for all LVAD device malfunctions (DMs) of all components, occurring in rotary LVADs implanted at a single center	Only 13% of device malfunctions were because of the pump itself, with controller failure (30%), battery failure (19%), patient cable failure (14%) or miscellaneous peripheral component failure (24%) much more common. Controllers are prone to faulty connections made by patients or caregivers, damage from dropping, and exposure to water or biological fluids. Device malfunctions and failure of the driveline were more common in the Heartmate II. General patient compliance did not appear to affect the rate or incidence of device component failure
2018	Driving After Left Ventricular Assist Device Implantation	Hanke et al.38	Worldwide, multi-center study	390 patients	16-question survey, with multi-method design including online, face-to-face and phone-based	Device-related alarms did occur in six cases (2.1%) of VAD patients driving. The majority being low battery alarms (5 of 6). One patient disconnected a battery cable by mistake (0.35%)

Appendix C: Qualitative studies

Year	Title	Authors	Location	No. participants	Research method/s	Key findings on VAD wearables
2011	From insiders’ perspectives: adjusting to caregiving for patients with left ventricular assist devices	Marcuccilli and Casida62	Detroit, Michigan, USA	5 caregivers (all female)	Semi-structured interviews, hermeneutic phenomenology (van Manen, 1990)	Caregiver tasks are initially overwhelming and stressful, with the task regime including changing sterile dressings, monitoring VAD function, troubleshooting alarms, and responding to emergency situations. Extra time and attention were needed to complete everyday tasks, for example bathing, dressing changes, night time routine, and loading and unloading the car (patient plus VAD equipment e.g. backup components/external power charging units)
2011	Lifestyle adjustments of adults with long-term implantable left ventricular assist devices: a phenomenologic inquiry	Casida et al.21	Detroit, Michigan, USA	9 patients (7 male, 2 female)	Semi-structured interviews, hermeneutic phenomenology (van Manen, 1990)	Patients felt a combination of awe and dismay when they looked at themselves in the mirror supported by a foreign object. Typically, a patient was connected to batteries during the day, and the power base unit at bedtime. Preparing for bed required major changes to routine due to management of the VAD external components, which also caused discomfort during sleep. Taking a shower was challenging and frightening and successful completion of this routine task required caregiver assistance for 3-6 months and took up to 1 h to complete. Finding clothing that both provided comfort and concealed the driveline and controller, yet fitted with a patient’s sense of style, was challenging, and resolved through trial and error. Female patients could not wear dresses. Patients eventually adjusted to a new normal, as they integrated VAD maintenance routines into their lifestyle and adjusted to living with the constant presence of equipment
2011	Sex and Intimacy Among Patients With Implantable Left-Ventricular Assist Devices	Marcuccilli et al.66	Detroit, Michigan, USA	9 patients (7 male, 2 female)	Semi-structured interviews, hermeneutic phenomenology (van Manen, 1990)	Patients demonstrated their own preferences for either hooking up to the batteries or the power base unit during sex. Some felt that the batteries got in the way, preferring the power cable, conversely others thought the opposite. The driveline was of particular concern. Abdominal binders were used to protect the external components such as the driveline and controller from becoming damaged or disconnected. Some single patients had insecurities about how a new partner would be turned off by the VAD, and a fear of rejection. However, these feelings were overcome by acceptance of the VAD by the patient’s partner
2012	Overcoming alterations in body image imposed by the left ventricular assist device: a case report	Marcuccilli and Casida63	Detroit, Michigan, USA	1 patient	Case report	A female VAD patient experienced difficulties finding practical and comfortable clothing to accommodate the VAD wearable external components. A waist-worn bag and belt with battery holsters was found to be most comfortable for this patient but was switched out occasionally with a vest due to skin irritation and rubbing from the driveline and abdominal binder. However, the company-provided vest design caused shoulder and neck pain. Challenges were experienced seasonally with winter coats, and difficulties were experienced readjusting the VAD wearables with clothing, especially after using the toilet outside the home. Women are unable to wear one-piece dresses. Apparel needs to be practical, comfortable, natural i.e. it must not accentuate the presence of the device and equipment
2012	Life in transition: a qualitative study of the illness experience and vocational adjustment of patients with left ventricular assist device	Overgaard et al.71	Copenhagen, Denmark	10 patients (6 male, 4 female)	Semi-structured interviews	In the 14-24 years age bracket, wearing the equipment in a conventional backpack left the driveline exposed and at increased risk of infection and driveline damage (fixed with tape), as well as backache. Patients could not easily hide their equipment, nor go swimming or do water sports. Some patients pushed the device to the very limits of battery power. In the 25-44 years age bracket, one patient’s husband put up hooks in the bathroom ceiling for wires, and a hook for the equipment bag. She wanted to toss the device away due to annoyance from the noises it made, but of course it was a part of her. A patient in middle to late adulthood didn’t like to take public transportation in rush hour due to being afraid of somebody disconnecting the driveline
2014	Family caregivers’ inside perspectives: caring for an adult with a left ventricular assist device as a destination therapy	Marcuccilli et al.64	Indianapolis, Indiana, USA	7 caregivers (1 male, 6 female)	Semi-structured interviews, hermeneutic phenomenology (van Manen, 1990)	Caregivers assist with daily dressing changes, device maintenance and respond to emergencies. For family caregivers, learning how to maintain the device is overwhelming and scary, but eventually becomes routine. Constant vigilance to ensure the VAD is always working and monitoring battery status creates pervasive stress for caregivers. However, the condition of worry and stress is perceived as an inevitable consequence of VAD patient care, and life in general
2017	‘Being’ a ventricular assist device recipient: a liminal existence	Standing et al.86	Newcastle Upon Tyne, UK	20 patients, 11 partners	Semi-structured interviews, interpretive phenomenological approach (Heidegger, 1962 and van Manen, 1984)	VAD implantation is a major disruption to the body, and day-to-day care involves maintaining a constant power supply, and cleaning/dressing the driveline exit wound. The physicality of the VAD and the need to protect it serves as a reminder of a patient’s vulnerability. One patient had to adapt to watching contact sports rather than playing, as he could no longer participate. Another could no longer rough-play with their young child. The need to maintain a constant power supply via battery or mains may contribute to a sense of ‘boundedness’
2017	LVAD-DT: Culture of Rescue and Liminal Experience in the Treatment of Heart Failure	Barg et al.8	New Haven, CT; Philadelphia, PA (3 sites); Oak Lawn, IL; Cleveland, OH, USA	39 patients (32 male, 7 female), 42 caregivers	Multi-site (six hospitals), semi-structured interviews,	Patients have high expectations of VADs when given the ultimatum of “LVAD or death”. However, expectations don’t meet reality with frequent driveline infections, multiple rehospitalizations, an uphill battle to recovery, heavy battery packs, long cords, fear of power outages, and coming to terms with a machine as a part of one’s body. A transplant is seen as preferable to rid oneself of the hardware and batteries. Travel is almost not worth the bother, with the amount of extra gear to take, fear of forgetting batteries or other components. The 15-foot power cord used at night initially creates terror about being plugged into the wall, but also perceived as a lifeline. The driveline, containing 4 cables, is seen is fragile, which creates a feeling of vulnerability. VAD is viewed as an ‘ironic’ technology, since it solves one problem, but creates a host of others. For patients who have no reserves in their heart, an accidental disconnection leads to immediate collapse and puts the patient in grave danger

Appendix D: Mixed and other method studies

Year	Title	Authors	Location	No. participants	Research method/s	Key findings on VAD wearables
2009	Usability and safety of ventricular assist devices: Human factors and design aspects	Geidl et al.35	Vienna, Austria	16 patients (14 male, 2 female)	Mixed: Qualitative interviews, standardized self-assessment questionnaire, manual skill test, and pilot study	38% of patients unintentionally disconnected parts of their system at least once with all of them blaming their own carelessness. Other usability problems included—cable damage requiring replacement (38%), rubbing of the parts on the body (38%), using another bag or carry system apart from the provided one (63%), overall noise emission too loud from pump, ventilators and alarms (56%), however, alarm too quiet to awaken from sleep (32%). Features desired included additional cable strain relief, a clear “snap-in” connector characteristic, and improved options and designs for carry solutions. The study found there was no correlation between the skill of the user and adverse events, despite users’ perception of their own fault. There is much potential for improvement in VAD usability since a considerable percentage of patients experienced potentially hazardous incidents that could be easily resolved by design
2011	Toward Total Implantability Using Free-Range Resonant Electrical Energy Delivery System: Achieving Untethered Ventricular Assist Device Operation Over Large Distances	Waters et al.94	Seattle, Washington, USA	n/a	Other: Literature review and VAD power system engineering experiment report	Infections continue to occur despite improved technology development of smaller, more durable implanted pumps; full advantage of such design improvements has not been achieved because external VAD peripherals remain essentially unchanged, including the driveline for data retrieval and power supply. There’s a relationship between exit site infections occurring as often as 70% after one year, repeat infections, and subsequent internal infection and sepsis. Exit site infections are the main cause of first hospital readmissions, and patients who developed exit site infections had 10 times as many readmissions as well as reduced survival compared to those who didn’t
2011	Intuitive use and usability of ventricular assist device peripheral components in simulated emergency conditions	Geidl et al.34	Vienna, Austria	96 paramedics (92 male, 4 female)	Other: Human Factors Engineering test, dummy test scenario, post-test evaluation questionnaire, video recording and analysis	71% of participants solved the staged emergency scenario, most by using the provided emergency card. Only 4% of participants could solve the test without the card. Participants recommended better, self-explanatory, unambiguous component labelling (e.g. displays, control elements, connectors) and a color-coded connection system. Intuitive operation and ease-of-use of the system for both basic handling and emergency procedures is crucial for all users, both trained and untrained
2014	TO VAD OR NOT TO VAD: That is the question. Improving the experience of receiving a Ventricular Assist Device (VAD)	Friedman and McMahon33	Rochester, Minnesota, USA	13 patients, 11 caregivers	Mixed: Observations (shadowing patients), stakeholder interviews, designer immersion	There remains much to improve on the user experience of the wearable component of VADs, including the need to consider body differences due to patient gender; the size, weight distribution, obtrusiveness and inconvenience of the VAD accessories especially during exercise or intimacy, the need for discretion and adaptability to personal style especially for work, the inability to get the batteries and controller wet during showering requiring a time-consuming routine, waterproof bag too big and cumbersome to be functional, limited sleeping positions due to external components and cord management, uncomfortable battery holster, dropping the all-in-one bag, Patient hacks included a modified carrying vest, carrying the VAD in a handbag purse, and wrapping the device in plastic cling wrap for showering, taking sponge baths
2015	A Simple Education Tool for Ventricular Assist Device Patients and Their Caregivers	Barber and Leslie7	Perth, WA, Australia	10 patients, 7 caregivers	Mixed: Literature review, development of booklet with key recommendations of driveline care, design development including peer and internal review, patient and caregiver evaluation, limited publication run	The importance of preventing trauma to the driveline site by immobilizing the line is an important finding in reducing infection in long-term VAD patients, the most common complication in this patient group. Early identification and reporting of driveline exit site infection have been shown to reduce morbidity and mortality

Appendix E: Review and overview studies

Year	Title	Authors	Location	Research method/s	Key findings on VAD wearables
2010	Improved Quantity and Quality of Life: A Winning Combination to Treat Advanced Heart Failure*	Starling87	Cleveland, Ohio, USA	Overview (Editorial comment)	Due to the percutaneous driveline and external power supplies of current devices, swimming and taking baths is prohibited and physical activities are restricted. Infection and malfunctions can be devastating. Design refinements will improve patient acceptance and quality of life
2011	The Future of Adult Cardiac Assist Devices: Novel Systems and Mechanical Circulatory Support Strategies	Bartoli and Dowling9	Louisville, KY, USA	Review: Technology review of novel left VAD, right VAD, biventricular VAD and TAH (total artificial heart) systems available, under trial or under development by various manufacturers	In the case of driveline failure, the cable of the HeartMate III can be replaced without having to replace the entire implanted pump itself due to a new modular design. This feature could also allow VAD upgrade to a TET power source if a totally implantable device is released
2012	Quality of Life and Left Ventricular Assist Device Support	MacIver and Ross60	Toronto, Ontario, Canada	Review: How QoL, physical function, and emotional health for VAD patients is measured, followed by an in-depth review of QoL results in VAD patients	Lower rates of device failure, driveline infection, and fewer complications requiring hospital readmission improves QoL levels. Managing day-to-day care and handling alarm states takes time to develop proficiency. Older patients also learn to adapt over time despite manual dexterity challenges. The position of the driveline was of concern to patients during sexual intimacy
2013	Physical Therapist Management of Patients with Ventricular Assist Devices: Key Considerations for the Acute Care Physical Therapist	Wells95	Baltimore, MD, USA	Overview (Book chapter)	Driveline infection rates are high; infections may lead to removal from the transplant waiting list, device explantation, plus carry a high risk of mortality. Education is key to ensure protocol is maintained for securing and protecting the driveline and dressing changes. A physical therapist secures the driveline and shows a patient how to modify physical movement and where to place external equipment to prevent damage during mobility
2014	Learning self-care after left ventricular assist device implantation	Kato et al.49	Sweden, Tokyo, Japan, Israel	Review: Current summary of self-care in VAD patients and caregivers, including VAD maintenance, lifestyle, monitoring, coping, adjustment and education	The need for a power supply external to the body is one of the main drawbacks of VADs. System maintenance, secure constant power supply, driveline care and preventing infection, driveline immobilization and daily inspection, maintaining hygiene and personal care, exit site wound management, restriction from certain activities, dealing with equipment during sexual intimacy, getting sufficient rest and sleep, handling alarms, responding to emergency situations, modification of self-concept and self-image, and dealing with stressors such as anxiety and fear of the complexity of device maintenance, are all themes surrounding the self-care practices of VAD patients and their caregivers
2014	Preparedness planning before mechanical circulatory support: a “how-to” guide for palliative medicine clinicians	Swetz et al.88	Rochester, MN, USA	Review: Exploring the role of a palliative medicine approach to help VAD patients plan to live as well as they can, for as long as they can, while still accomplishing their overall goals of care during both use and approaching end-of-life	To considerately prepare a patient for possible death while being treated on VAD, a palliative medicine approach would ask whether: (1) In the event of power issues or device failure, the patient would want heroic measures to save their life, or just to be kept comfortable and let things go; and (2) In the event of severe infection and where antibiotic treatment impacts quality of life, they wish for such treatment to be limited
2015	Psychosocial issues in ventricular assist device implantation and management	Petty and Bauman75	Minneapolis, Minnesota, USA	Review: Elements of the psychosocial assessment for prospective VAD patients, including the accepted model for evaluation, discharge planning strategies, post-discharge support to patients and their caregivers, and strategies for when the post-discharge period doesn’t go as planned	Caring for a VAD is more difficult than caring for a transplant due to not being completely implantable, the need for constant electrical power supply, and frequent dressing changes. Financial strain can lead to death, if a family can’t afford to pay their electricity bill and their power is cut off
2016	Beyond the VAD: Human Factors Engineering for Mechanically Assisted Circulation in the 21st Century	Throckmorton et al.90	Philadelphia, PA and McLean, VA, USA	Review: Relevant literature on Ovid MEDLINE and PubMed regarding human factors and VADs; findings include usability studies, clinical decision support tools, patient-centered therapy including QoL and satisfaction studies, human-device interaction and knowledge gaps	There is a need for more attention to user-centered design approaches that include both qualitative and quantitative assessments of human-device interactions to mitigate risk and failure. There are many cases where a combination of machine failure and human error has resulted in death. Issues include self-reported careless usage of auxiliary components, general confusion in how to handle the system, and a need to design clear emergency cards for use in emergency scenarios, as well as quality of life impact from wearable components
2016	What the psychiatrist needs to know about ventricular assist devices: a comprehensive review	Caro et al.19	Cleveland, Ohio, USA	Review: Literature review to identify key issues relevant to the practice of consultation-liaison psychiatrists	VAD recipients and their caregivers must adapt to many changes in their lifestyle, body image, and sexual life. Small studies have described changes in self-image after VAD implantation due to the driveline exiting through the skin and having to carry the external components of the VAD. Patients are able to adapt to changes in self- and body- image by accepting the fact that the VAD allows them to continue to be alive. Large studies assessing psychologic adaptations to these changes are lacking, and current literature limits the ability of these results to be generalized
2016	Adaptation and coping in patients living with an LVAD: A metasynthesis	Abshire et al.4	Baltimore, MD, USA and Sydney, Australia	Review: Qualitative meta-synthesis of 7 studies using Lazarus and Folkmans’ Transactional Model of stress and coping, to enhance understanding of living with a VAD, for the purpose of designing and delivering services to support VAD patients	Stressful aspects of living with a VAD include alteration of patient body image, managing the device, limitation of activities such as bathing and swimming, driving restrictions, issues for intimacy, and difficulty in adjustment. Some patients can’t accept limitations e.g. ignoring advice and going boating. Patients cope by developing routines and systems to manage the device e.g. for showering and carrying the device comfortably and safely. Coping is difficult when, despite best efforts, driveline infection or VAD malfunction occurs anyway. Concern for battery life impacts patients’ sense of return to normalcy and life satisfaction
2017	The Patient’s Informal Caregiver	Saunders79	Detroit, Michigan, USA	Overview (Book chapter)	Caregivers assist with getting dressed, bathing, bedtime routine, perform sterile dressing changes, handle battery issues and the docking system, monitor VAD function and alarms, prepare back up batteries charged and dressing materials, prepare for emergencies. They adapt over time but feel overwhelmed. Caregiver spouses watch the flow and rate of the VAD during sex
2017	Outpatient Management: The Role of the VAD Coordinator and Remote Monitoring	Christensen et al.23	USA, Canada, Austria, Germany, Norway	Overview (Book chapter)	Ongoing care of VAD outpatients includes maintaining the driveline exit site and dressing. Routine Outpatient Evaluation includes technical check and comprehensive visual inspection of external components to rule out physical damage, visual and tactile (and X-ray if needed) driveline check, review of device function and preventative maintenance
2018	Wearable systems	Schlöglhofer and Schima83	Vienna, Austria	Overview (Book chapter)	Technical complications such as driveline damage and safety flaws in power supply systems or connector designs still occur. Eliminating the driveline for external power supply could eliminate adverse events related to this component including infection and reduce the number of daily-life restrictions on patients. Until such TETS technology is available, battery technology improvement will enable smaller, lighter, and more durable batteries with larger capacities. A user-centered design approach, where human factors engineering and human behavior are considered, could potentially help improve Quality of Life for VAD patients, decrease limitations on certain activities, minimize caregiver burden and reduce emotional distress
2018	Left Ventricular Assist Devices–A State of the Art Review	Feldmann et al.29	Hannover, Germany	Review: Current implantable left ventricular assist devices, different design concepts and implantation techniques	VAD driveline may exit on either upper right or left quadrant of abdomen. Advancements in batteries and microprocessors have made VAD systems smaller and lighter. One VAD manufacturer provides an additional remote monitoring system. Male patients often show great interest in the technical aspects of their device, and women more typically seek other paths to emotional acceptance, for example, giving their device a personal nickname
2018	Mental health interventions during ventricular assist device therapy: a scoping review	Tigges-Limmer et al.91	Bad Oeynhausen and Göttingen, Germany	Review: Scoping review (Levac et al. 2010) regarding what is known about mental health intervention carried out in VAD teams as patients progress through VAD treatment stages. Recommendations for conducting interventions are synthesized from reports of single-center experiences	Daily, patients need to integrate the device so that it feels like a natural part of their body and body image. Worry over alarms and malfunction may be correlated with sleep disruption, lower quality of life, and mental health issues