Keywords

1 Introduction

Pressure ulcers is local injury that occur to the skin and internal tissues of bony protrusions due to excessive pressure and shear force [1]. It requires lots of cost and time for treatment and negatively affects a wide range of areas such as functional activities, psychosocial factors, participation, and quality of life of people with spinal cord injuries [2, 3].

The wheelchair cushion is representative intervention for preventing pressure ulcers in people with spinal cord injuries. The wheelchair cushion can prevent skin damage by dispersing pressure of buttocks in sitting position [4]. It is largely divided into traditional technologies in the form of air, gel, and foam, and new technologies that combined various materials and off-loading technologies [5].

People with spinal cord injuries are restricted from sensory function below the damaged neurologic segment [6, 7]. So, even though the wheelchair cushion is used, excessive pressure and shear force in the buttocks caused by using powered seating functions and outdoor activities are not recognized by themselves. Due to this, people with spinal cord disabilities are exposed risk of secondary pressure ulcers.

Therefore, this study aims to develop an ICT-based system that can monitor pressure distribution and posture changes in real-time when people with spinal cord disabilities use wheelchairs, and to investigate their satisfaction and psychosocial effects.

2 Method

2.1 Participants

The participants of this study were three people with spinal cord injuries living in the community. All of the participants were male, and the average age was 43.7 years. They are complete cervical level injuries (C3,4 and 6) and the average duration of the onset is 15.3 years. Two participants use power wheelchairs and the other uses manual wheelchair. Their average daily use of wheelchairs is 8.3 h (Table 1).

Table 1. Characteristics of participants
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2.2 ICT-Based Customized Off-Loading Cushion

2.2.1 Customized Off-Loading Cushion

The off-loading cushion is a wheelchair cushion with off-loading technology to prevent pressure ulcers. Off-loading technology is distributing the pressure by removing the seat surface and adjusting the height in contact with the main bony protrusion of the buttocks (Ischial Tuberosity, Coccyx and Greater Trochanter) in a sitting position [8]. It is contoured to fit the shape of the buttocks, so it is possible to maintain stability when seated in a wheelchair and minimize shear force (Fig. 1).

Fig. 1.
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Off-loading cushion

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The off-loading cushion was customized through clinical and manufacturing phase. In clinical phase, occupational therapist evaluates the clinical feature and the wheelchair being used. After the evaluation, we captured and scanned a sitting posture using a vacuum bag and 3D scanner. Next, we performed 3D modeling through CAD (Computer Aided Design) programs to fit each user’s buttocks. And we adjusted the seat surface to minimize the pressure of the buttocks based on the result of clinical evaluation. In manufacturing phase, we performed a simulation process using the CAM (Computer Aided Manufacturing) software. After that, EVA (Ethylene-Vinyl Acetate) foam was processed into a cushion using a CNC (Computer Numerical Control) machine (Fig. 2).

Fig. 2.
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Manufacturing process of customized off-loading cushion

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2.2.2 Pressure Distribution and Posture Change Monitoring System

Monitoring system is divided into hardware and software. The hardware of system consists of sensors, BLE (Bluetooth Low Energy), and a multiplexer. A total of 10 sensors were attached based on the coccyx, greater trochanter, and ischial tuberosity, which are the most common areas for pressure ulcers in sitting position (Fig. 3).

Fig. 3.
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The hardware of monitoring system

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Three sensors were attached 2–3 cm below the coccyx and four on the slope between the ischial tuberosity and the thigh, and one on the ischial tuberosity area to detect the pelvis forward sliding. In addition, two sensors were attached to the greater trochanter to detect the sideways sliding of the pelvis. The hardware was placed on the bottom of the off-loading cushion using the case.

The data input through the sensor is transmitted to the monitoring application, which is the software of the system. The application can be linked with the user’s tablet or smartphone. Users can intuitively check the pressure distribution and the alignment of pelvis through changes in pressure values and colors. The degree of abnormal posture can be known through the icons. It also provides immediate feedback on posture status to users by providing notifications through banners on their smartphones or tablets when abnormal posture is detected (Fig. 4).

Fig. 4.
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The software of monitoring system (monitoring app.)

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2.3 Study Protocol

Participants performed activities of daily living and community activities for a week with ICT-base customized off-loading cushions. After that, we were measured satisfaction and psychosocial effect on ICT-based customized off-loading cushions.

2.3.1 Satisfaction

Satisfaction on ICT-based customized off-loading cushions was measured through K-QUEST 2.0 (Korea-Quebec User Evaluation of Satisfaction Assistive Technology 2.0). This is a 12-item related to the satisfaction on assistive technology device (8 items) and assistive technology service (4 items). Each item is scored on a 5-point Likert scale ranging from 0 to 5, and a higher score means higher satisfaction [9].

2.3.2 Psychosocial Impact

The psychosocial impact of ICT-based customized off-loading cushions was measured using K-PIADS (Korea-Psychosocial Impact of Assistive Devices Scales). This is a 26-item, self-report questionnaire and consist of three sub-scale: Competence (12 items), Adaptability (6 items), and Self-esteem (8 items). Each item is scored on a 7-point Likert scale ranging from −3 to 3. A positive score mean that assistive technology device has a positive psychosocial impact on user [10].

3 Result

3.1 Satisfaction

The average for the mean score of the assistive technology device was 4.6. The mean score of comfort and effectiveness was the highest, and the mean score of weight and durability was the lowest (Table 2).

Table 2. The result of satisfaction on assistive technology device
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The average for the mean score of the assistive technology service was 4.5. The mean score of service delivery and professional service was the highest, and the mean score of repair and follow-up service was the lowest (Table 3).

Table 3. The result of satisfaction on assistive technology service
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3.2 Psychosocial Impact

The mean scores for competence, adaptability, and self-esteem were 2.39, 2.61, and 2.42, respectively. it means that the ICT-based customized off-loading cushion had a positive to very positive impact on the participants. (Table 4).

Table 4. The result of psychosocial impact
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4 Conclusion

People with spinal cord injuries suffer from permanent physical and sensory dysfunction due to trauma or disease. Therefore, intervention strategies should focus on participation and improvement of quality of life rather than functional recovery. For a healthy life for people with spinal cord disabilities, it is necessary to actively cope with complications such as pressure ulcers that reduce the quality of life. A wheelchair cushion is a technical intervention to prevent pressure ulcers. In this study, we developed a wheelchair cushion applying customized off-loading technology and ICT technology that can monitor body pressure distribution and posture change. As a result of applying it to three people with spinal cord disabilities living in the local community for a week, satisfaction with the ICT-based off-loading cushion was appropriate, and it had a positive psychosocial effect. Through this pilot study, we derived the need for a covering to protect hardware from urinary incontinence and improvement in applications such as colors that can intuitively recognize pressure distribution during outdoor activities. Currently, we are supplementing software and hardware based on the results derived. In the future, we intend to investigate the effects of ICT-based off-loading cushions on the clinical effectiveness, quality of life and participation through a randomized controlled trial study for people with spinal cord disabilities living in local communities. This study has a limitation in that it was conducted with only three male subjects. Therefore, we intend to include balanced gender subjects with an appropriate number of sampling to test for statistical significance in future study. We expect this to be useful in improving the quality of life for people with spinal cord injuries as a health care system.