Hand assistive device “GRIPIT” for people with SCI

Goal

To develop a compact, light, and wearable assistive device that enables people with hand paralysis to attain one type of grasp via single operation.

 

Approach

Compactness and weight is one of the most important factor in hand exoskeletons, or wearable robots for the hand. However, there are limitations cause from various transmission and actuation methods for high degree of freedom. We focused on developing a soft wearable device named GRIPIT that enables people with hand paralysis to attain only one type of grasp via single operation. We selected a tripod grasp as the posture that GRIPIT will assist because this grasp is frequently used in school and offices for such activities as writing and grasping small objects. We focused on building an assist device for use in a school or office environment because a peak age range for SCI is 15 to 29 years old, a time of life when many people are in school or building a career. Hand paralysis for people in this age range means an unavoidable change of occupation or serious problems with finishing one`s education.

 

Current Status

Three fingers should be gathered into a single point, and the forces applied to an object should be well distributed for a stable grasp. The grasp can fail when the three fingers fail to gather or when one finger applies higher contact force to the object than the others. Precise force and position control of dozens of DOFs are required for GRIPIT to gather three fingers into a single point with equal force. The underactuation mechanism, which is widely used in robotic hands and wearable hand robots to increase adaptability, is applied to the tendon-driven mechanism to gather the fingers into a single point and to distribute contact forces adaptably without complicated controlling of numerous DOFs. We are going to extend grasp type for various situation. Moreover, we are trying to develop our device that the users can wear extremely easier. Final goal of our project is modularization of the device: User can bring several devices for each grasp type and switch the device in various situation.

Related papers and patents

B. Kim, H. In, D. Lee, and K.-J. Cho, “Development and assessment of a hand assist device: GRIPIT,” Journal of Neuro engineering and Rehabilitation, 2017. [PDF]

B. C. Kim, K. J. Cho, “Development of tendon maintain system for tendon driven wearable device”, Korean Society Of Precision Engineering Conference, Spring, 2015.
Byungchul Kim, Hyunki In, and Kyu-Jin Cho, “strap driven system for hand soft exoskeleton,” International Biomedical Engineering Conference(IBEC), 2014,
Byungchul Kim, Daeyoung Lee, Ji-suk Kim, Hyunki In, Kyu-jin Cho, “Design and evaluation of glove type penholder”, Rehabilitation Engineering and Assistive Technology Society of Korea (RESKO), 2012
Jiyoung Park, MyungJoon Lim, Kuem Ju Lee, Hyosun Kweon, Byungchul Kim, Kyujin Cho, Hyun Choi, “Usability Assessment of a Glove Type Writing Assistive Device for People with Spinal Cord Injury”, 9th i-CREATe (international Combetion on Rehabilitation Engineering & Assistive Technology
MyungJoon Lim, Jiyoung Park, Kuem Ju Lee, Hyosun Kweon, Byungchul Kim, Kyujin Cho, Hyun Choi, “Usability of a New Writing Assistive Device for Persons with Cervical Spinal Cord Injury”, 13th AAATE (Association for the Advancement of Assistive Technology)

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· E-mail : kbc1990 at snu.ac.kr
· Research Topic : Soft wearable robots & Clinical trials

Ph.D. Candidate

Byung-Chul Kim

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· E-mail : songjl2000@gmail.com
· Research Topic : Bionic hands & Wearable robots

Designer

Jeong-Ryul Song