500 Section - Development and Functional Evaluation of a Novel Electric Prosthetic Hand Controlled by Wearable Wireless Sensors in a Transhumeral Amputee: Comparison with a Multi-Articulating Myoelectric Hand

Tuesday, May 19, 2026

6:00 PM - 7:30 PM PT

Presenting Author/Autor expositor(s)

KY

Kenichi Yoshikawa, PhD

Chief physical therapist
Ibaraki Prefectural University of Health Sciences Hospital
Inashiki-gun, Ibaraki, Japan

Corresponding Author/Autor a quien dirigir la corr(s)

Yukiyo Shimizu, MD, PhD (she/her/hers)

Associate Professor
University Of Tsukuba
Tsukuba, Ibaraki, Japan

Co-Author/Coautor(s)

TM

Takahiko Mori, PhD

Associate Professor
Department of Electrical and Electronic Engineering, Shonan Institute of Technology
Fujisawa-shi, Kanagawa, Japan
DK

Daisuke Katane, BOT

RPT
Ibaraki Prefectural University of Health Sciences Hospital
Inashiki-gun, Ibaraki, Japan
KK

Kazunori Koseki, MPT

RPT
Ibaraki Prefectural University of Health Sciences Hospital
Ami-machi, Ibaraki, Japan
HT

Hiroyuki Torishima, RPO

RPO
Saitama Prosthetics and Orthotics Manufacturing Service Co., Ltd.
Saitama-shi, Saitama, Japan
SK

Shigeki Kubota, OTR, PhD

Professor
Ibaraki Prefectural University of Health Sciences
Ami-machi, Ibaraki, Japan
HM

Hirotaka Mutsuzaki, MD, PhD

Professor
Department of Orthopaedic Surgery, Ibaraki Prefectural University of Health Sciences
Ami-machi, Ibaraki, Japan

Objectives : We developed a novel electric prosthetic hand triggered by body movements using wearable wireless sensors. This study reports its first clinical application in a regular myoelectric prosthesis user, comparing the functional performance of both hands.

Design: The participant was a male in his 50s with a left transhumeral amputation (7 years post-injury) who has been using an i-Limb Quantum (i-Limb) for one year. The novel hand is a lightweight, 3D-printed model. It features four-finger opening/closing controlled by a wireless sensor detecting foot plantarflexion/dorsiflexion, and thumb opposition/flexion/extension via manual operation. Evaluation metrics included the Simple Test for Evaluating Hand Function (STEF; evaluated by average time per completed item), the Action Research Arm Test (ARAT), and the Box and Block Test (BBT). Less than 20 minutes of operational training with the novel hand was permitted prior to measurement.

Results: ARAT scores were 34 for the i-Limb and 35 for the novel hand. Gross movement and grasping were favorable for both, but fine pinching tasks were difficult for both hands to execute. In the STEF, the novel hand (9.7 s) was faster than the i-Limb (15.3 s) in the 1.5 cm cube task, and only the novel hand was able to perform the pin insertion task. The BBT score was 11 blocks for the i-Limb and 6 blocks for the novel hand.

Conclusion: In the ARAT, the novel hand achieved a score equivalent to the proficiently used i-Limb despite only a short training period. This is attributed to the intuitive operation and ease of learning provided by the wireless control of the novel hand. Although challenges remain regarding fine motor control and speed adjustment, the results suggest its usefulness as a new option for electric prosthetic hands.