Developing a Novel Prosthetic Hand with Wireless Wearable Sensor Technology Based on User Perspectives: A Pilot Study.

Myoelectric hands are beneficial tools in the daily activities of people with upper-limb deficiencies. Because traditional myoelectric hands rely on detecting muscle activity in residual limbs, they are not suitable for individuals with short stumps or paralyzed limbs. Therefore, we developed a novel electric prosthetic hand that functions without myoelectricity, utilizing wearable wireless sensor technology for control. As a preliminary evaluation, our prototype hand with wireless button sensors was compared with a conventional myoelectric hand (Ottobock). Ten healthy therapists were enrolled in this study. The hands were fixed to their forearms, myoelectric hand muscle activity sensors were attached to the wrist extensor and flexor muscles, and wireless button sensors for the prostheses were attached to each user's trunk. Clinical evaluations were performed using the Simple Test for Evaluating Hand Function and the Action Research Arm Test. The fatigue degree was evaluated using the modified Borg scale before and after the tests. While no statistically significant differences were observed between the two hands across the tests, the change in the Borg scale was notably smaller for our prosthetic hand (p = 0.045). Compared with the Ottobock hand, the proposed hand prosthesis has potential for widespread applications in people with upper-limb deficiencies.

Spiral sockets for various types of stumps in transhumeral amputees: a case series.

BACKGROUND: Fitting a stump prosthesis is difficult in transhumeral amputees because of the stump's conical form. Shoulder harnesses for suspension can cause neck and shoulder pain. We developed a novel spiral socket transhumeral prosthesis to overcome these difficulties. We investigated its safety and effects in transhumeral amputees. CASE REPORT: Five transhumeral amputees with a mean age of 50.8±23.8 (range, 19-75 years) were fitted with the spiral socket between April 2013 and February 2017. Spiral sockets can adapt to changes in the shape of the stump, even in early stages when stump shape can change. It can also adapt to an hourglass-shaped stump. CLINICAL REHABILITATION IMPACT: The novel spiral socket transhumeral prosthesis might be useful for socket-stump adaptation at various stages after amputation. It may also be used for irregularly shaped stumps and can possibly prevent secondary complications, including neck and shoulder pain and skin disorders.

Proposal of bioinstrumentation using flex sensor for amputated upper limb.

We previously proposed a new bioinstrumentation using the shape deformation of the amputated upper limbs without using the myoelectricity generated on the skin of the upper limbs. However many electronic parts were required owing to a bridge circuit and multi-amplifier circuits so as to amplify a tiny voltage of strain gages. Moreover, the surplus heat might occur by the overcurrent owing to low resistance value of strain gages. Therefore, in this study, we apply a flex sensor to this system instead of strain gages to solve the above problems.

Proposal of bioinstrumentation using shape deformation of amputated upper limb.

Some upper limb amputees have been annually supplied with myoelectric prostheses by social rehabilitation promotion services. However, the persons supplied with the prostheses have been limited because a supply system has not been established yet. Accordingly, we propose a new bioinstrumentation using the shape deformation of the amputated upper limbs without using the myoelectricity generated on the skin of the upper limbs. The repeatability is superior to the myoelectricity because the shape deformation is directly measured by strain gages and also the cost is much superior to the myoelectricity.