Keywords

1 Introduction

The classification and terminology of assistive products are addressed explicitly in the ISO 9999 standard [1]. The standard defines an assistive product as “optimizing a person’s functioning and reducing disability.” In other words, an assistive product can optimize a person’s functioning or reduce disability. With the recent development of robotics, many assistive devices are incorporating robotics to improve their functionality. The terms robot and robotics are well-defined in ISO 8373:2021 [2].

A robot is defined as a “programmed actuated mechanism with a degree of autonomy to perform locomotion, manipulation or positioning,” and robotic technology is defined as “practical application knowledge commonly used in the design of robots or their control systems, especially to raise their degree of autonomy” [2]. Since IEC/TR 60601-4-1 defines a medical robot as a “robot intended to be used as medical electrical equipment or system,” an assistive robot can be defined as a “robot intended to be used as an assistive product” [3]. Similarly, a care robot is a “robot intended to be used for caring persons with disability or elderly persons.”

These care robots are intended to support the care, nursing, and physical activities of the care recipient, easing the burden of caregiving and improving the quality of life of the elderly or disabled and their families. Care robot products are developed around basic activities such as Feeding, Personal toileting, Hoist, and Posture-changeable. However, there are still no clear definitions, item classifications, and safety standards for care robots, so their dissemination has many difficulties.

In this study, a care robot is defined as a “robot that assists the daily life of the disabled or the elderly who have difficulties in daily life.” However, although care robots can be physically burdensome by reducing human intervention, they can also be dangerous depending on their ability to recognize situations. Therefore, we propose a standard that defines safety requirements specific to care robots and includes an evaluation method to test safety based on these requirements. As an example of applying this standard, we show a standard for Feeding robots’ safety and performance methods.

As for standards related to care robots, ISO 21856, the common standard for assistive devices, was recently published [4]. It consists of 29 clauses, with general requirements in clause four and individual requirements in clauses 5 through 26. The international standard for medical rehabilitation robots is IEC 80601-2-78 [5]. This standard adds mechanical hazards defined by robots to the mechanical hazards in IEC 60601-1, a common standard for medical devices. It is necessary to refer to it in the care robot standard because it considers the characteristics of robots. IEC 60601-1, a common safety standard for all medical devices, states that the primary user may be a patient rather than a clinical professional. Therefore, for medical robots with a degree of autonomy (DOA), the user’s situational awareness can be an essential safety factor [6]. Since the primary users of care robots are non-expert care receivers, and caregivers, the risk of losing situational awareness should also be considered. Methods for evaluating this risk include usability engineering in the field of medical devices [7] and usability evaluation in the field of assistive devices.

Medical devices, assistive devices, and children’s products that have been used for a long time have well-documented safety requirements. However, the field of care robots, which has a short history, still lacks safety standards. This study proposes standards for safety and verification methods suitable for care robots by referring to existing standards.

2 Safety Standard for Care Robots

2.1 Definition of Care Robot

Care or care service is defined as “the act of providing physical Care or care service as “the act of providing physical or mental assistance to the elderly or disabled who have difficulty maintaining daily activities on their own.”

Thus, a care robot can be defined as “a robot that assists the daily life of the disabled or the elderly who have difficulties in daily life.”

2.2 Types of Care Robots

Care robots include Feeding robots, Hoist robots, Personal toileting robots, posture-changeable robots, and Rollator robots to reduce the burden on caregivers and improve the quality of life of care recipients (Fig. 1) [9].

Fig. 1.
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Types of care robots [9]

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2.3 Structure of Care Robot Safety Standard

The safety standards for care robots are divided into common safety standards, individual safety standards, care data standards, and care robot degrees of autonomy (Fig. 2).

Fig. 2.
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Hierarchy of care robot standards

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The common safety standard for care robots covers general safety requirements that should be applied to care robots. In contrast, the individual care robot standard covers requirements that are difficult to apply in general in consideration of the characteristics of individual care robots and must be considered for each item. Therefore, the Care Data Standard and the Care Robot Degree of Autonomy Standard are different standards that can be referenced for care robots.

2.4 General Requirements

For risk analysis and management of care robots, the procedures of ISO 14971 or ISO 12100 are applied [10, 11]. In addition, for care robots classified as medical devices, IEC 62366-1 is used to identify hazardous situations [7], and for care robots with embedded programs, IEC 62304 is used [12]. In particular, for care robots with autonomy, the loss of the user’s situational awareness is considered a hazard [13].

Multifunctional care robots with two or more functions must meet the safety and performance requirements in individual standards according to the primary function proposed by the manufacturer. Functions other than the primary function shall be classified as minor and meet common safety requirements.

If the care robot supports wired and wireless communication (Wi-Fi, Bluetooth, USB, RS-232, LAN, etc.) capabilities, it must be designed for availability, confidentiality, and integrity within the risk management process.

2.5 Safety Requirements for Care Robots

Safety requirements are categorized into electrical safety, mechanical safety, cleaning and disinfection, environmental factors, and hazardous materials.

Electrical safety is required to comply with national safety certification requirements. If there are no national safety certification requirements, at least meet the requirements for leakage current, withstand voltage, and over temperature. In addition, built-in batteries, emergency stop, protective stop, and electronics compatibility are required (Table 1). Finally, mechanical safety requirements are provided for the structure, pinching, squeezing, and restraint to ensure that the user of the care robot is not at risk of mechanical harm.

Requirements for hazardous substances are provided for parts of the robot that come into contact with the human body. The allowable values of hazardous substances are based on the Korean certification (KC) standard for children’s products [8].

To prevent harm from noise, the standard requires a maximum noise level of no more than 50 dB in sleeping environments, 65 dB indoors, and 85 dB outdoors. In addition, the standard requires classification for water resistance according to IEC 60529 [13].

Table 1. Electrical Safety Requirements for care robots
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2.6 Example of Feeding Robot

This section introduces the individual requirements of a feeding robot. The shape of a feeding robot is shown in Fig. 3. The safety of the feeding robot is further tested for impact energy, static load, and repetitive durability (Table 2). The performance of the feeding robot is further evaluated through pose accuracy (ISO 9283) [14], continuous use time, and feeding assistance success rate (Table 3).

Fig. 3.
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Feeding Robot

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Table 2. Additional Safety Requirements for Feeding robot
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Table 3. Performance Requirements for Feeding robot
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3 Conclusion

Recently, various research projects on care robots have been started and are in progress. However, due to the lack of relevant standards, there may be problems with the steps for licensing or certification for future productization. Therefore, we developed a standard for safety requirements for care robots in this study.

The requirements for electrical safety and mechanical safety, which are safety requirements for medical devices, were investigated and applied [6]. The mechanical risk factors defined by robots were additionally reflected by referring to ISO 13482 [16]. In addition, since care robots use robotics and the primary users are non-experts, the risk of situational awareness loss was considered by referring to IEC 80601-2-78, an international standard for rehabilitation robots [5], and cybersecurity was also added. Performance issues will be addressed in individual standards for care robots to be developed in the future.

In a situation where standardization of safety evaluation of care robots is actively needed, it is expected that securing product safety and consumer trust through normal development will be very important for the successful settlement and expansion of the care robot industry. Furthermore, the developed standards can be used for licensing and establishing policies for care robots, and manufacturers will be able to ensure safety in the development stage of care robots.

The addition of robot and robot technology definitions, automatic toileting systems, power assist units for assistive products for walking, and feeding robots to ISO 9999 has paved the way for developing and institutionalizing international standards for care robots [1]. Therefore, it can be promoted as an international standard based on the current standards. In addition, we will also develop standards for individual care robot items so that care robots currently under development can be released to the market with guaranteed safety and performance.