As the average life expectancy is increased due to improved dietary life and high-quality medical service, the world is rapidly aging and the demand for healthcare services for the elderly is increasing. Besides, a pandemic such as Coronavirus disease 2019 (COVID-19) can make numerous severely ill patients, that results in the demand for healthcare services for both patients and medical staffs. To cope with these demands, nursing robots (or care-robots) are being developed that can help improve the quality of the care service by reducing the intensity of caregivers’ labor and raising the independence of care receivers.
The main focus in developing nursing robots is usability from the perspective of both service provider and receiver. Novel technologies including passive mechanism and soft robotics have a potential to enhance the usability by making the robot lighter, smaller, and realizing safe and convenient to interact with users.
Center for Medical Robotics (CMR) has been developing several nursing robots such as transfer assist robots and sit-to-stand assist robots for the elderly and the disabled. In addition, the wearable robot for the caregivers or laborers has been developed to augment their physical capability and to prevent the musculoskeletal disease induced by handling heavy loads or continuing a repetitive movement.
Sit-to-stand and walking assistance device
Most elderly people complain about the discomfort of movements such as a sit-to-stand (STS) motion through losing their muscular strength of lower extremity over aging. A novel passive sit-to-stand and walking (STSW) assistance device is developed to aid in physical support for indoor daily life of the elderly.
The STSW assistance device is actuated by a pneumatic cylinder and a gas spring. The standing motion is driven by extension of actuators and the sitting motion is driven naturally with gravitational force of user’s weight that reloads actuators. According to the experiment result, the reduction rate of average maximal voluntary isometric contraction with assistance by the STSW device is about 51.2%. This means that users with the assistive device can stand up by using only about half of muscular activation in the case of natural standing up.
Reference: S.-W. Kim et al., “Design and experiment of a passive sit-to-stand and walking (STSW) assistance device for the elderly,” IEEE/EMBS 2018 EMBC, pp. 1781-1784
Co-care modular robot
A power-assist-modular (PAM) mobile robots can move easily at a confined area of the hospital by using omni-directional dual-offset caster and assist three major physical works of nurses: moving a heavy nursing cart, aiding sit-to-stand motion of patients and elders, and lifting patient from bed to bed or wheelchair. This robot system was demonstrated at Seoul National University Hospital Medical Device Usability Testing Center and prove its effect of reducing intensity of physical nursing labor.
PAM + Nursing cart
PAM + PAR1
(STS assistive device)
Glowing Sling for patient transfer
Most of the transfer assist devices utilize a sling to transfer the care receiver. A sling is a fabric sheet that can enclose the care receiver’s body to support weight and is attached to devices by fastening them to device supports or cables. Before the transfer process, the sling needs to be placed underneath the patient’s body by manual operations done by the caregiver. This includes lifting the patient, spreading the sling under the patient’s body, and connecting the sling to the transfer assist device, which is the most laborious task while using the transfer assist device.
We propose a Growing Sling to increase the usability of the transfer assist device while maintaining the safety and comfort of the patient. The new sling design can be automatically and smoothly inserted underneath a patient by adopting the growing mechanism powered by air pressure or tension of the cable. Thanks to the characteristics of the growth mechanism that easily enters even a narrow gap and does not move in relative motion with the surrounding environment, there is a great usability improvement effect, by using Glowing sling, in the process of sling preparation or removal.
Suit type wearable robot for assisting care givers
Patient transfer is a necessary procedure for providing basic care to bedridden patients and the elderly. The process consists of lifting patients who are lying down on a bed and transferring them to required places, such as another bed, a chair, or a wheelchair. In Korea, many caregivers currently perform the patient transfer manually, both at healthcare facilities and in homes, by pulling the patient against friction or by lifting them. It can take a substantial amount of labor intensity and even causes muscular-skeletal disorders in caregivers.
The purpose of this research is to bring a novel suit type wearable robot to the caregivers. In the case of the conventional power assistant suits, a large and heavy actuator was required to obtain the required power. Therefore, there was a problem that the weight of the actuator itself had to be overcome, and the size of the system is inappropriate to be used in the care field. In the developing wearable robot, a novel passive brake mechanism based on a tendon clamping is used to minimize the size of the actuator. The developed wearable robot can be fundamentally excluded from the motion disturbance caused by the tendon structure by releasing the brakes and loosening the tendons when muscular assistance is not needed.