sEMG Sensor Using Polypyrrole-Coated Nonwoven Fabric Sheet for Practical Control of Prosthetic Hand

One of the greatest challenges of using a myoelectric prosthetic hand in daily life is to conveniently measure stable myoelectric signals. This study proposes a novel surface electromyography (sEMG) sensor using polypyrrole-coated nonwoven fabric sheet as electrodes (PPy electrodes) to allow people with disabilities to control prosthetic limbs. The PPy electrodes are sewn on an elastic band to guarantee close contact with the skin and thus reduce the contact electrical impedance between the electrodes and the skin. The sensor is highly customizable to fit the size and the shape of the stump so that people with disabilities can attach the sensor by themselves. The performance of the proposed sensor was investigated experimentally by comparing measurements of Ag/AgCl electrodes with electrolytic gel and the sEMG from the same muscle fibers. The high correlation coefficient (0.87) between the two types of sensors suggests the effectiveness of the proposed sensor. Another experiment of sEMG pattern recognition to control myoelectric prosthetic hands showed that the PPy electrodes are as effective as Ag/AgCl electrodes for measuring sEMG signals for practical myoelectric control. We also investigated the relation between the myoelectric signals\u27 signal-to-noise ratio and the source impedances by simultaneously measuring the source impedances and the myoelectric signals with a switching circuit. The results showed that differences in both the norm and the phase of the source impedance greatly affect the common mode noise in the signal

Cost-Effective Prosthetic Hand Controlled by EMG

A cost-effective five-finger prosthetic hand is designed from aluminum, modeled and controlled using surface Electromyography (EMG) signals, which are obtained from the human body. Force sensors are used to control required forces needed to grasp and pick objects. A prototype hand is developed and it is experimentally tested to reproduce a wide spectrum of human hand motions. The size of the five-finger hand is similar to an adult male human hand, and it is capable of reproducing most of movements. Each finger has the same number of links as the real/human hand. Each finger also has a force sensor used to sense applied forces to the fingertip, subsequently dictating to the amputee to take specific actions. By using a vibration motor, the amputee knows if any ‘object’ is in touch with the prosthetic hand. Compared to other existing (and more expensive hands that include biotic sensors and smart motors), it is shown and it is experimentally validated that this cost-effective prosthetic five-finger hand is durable, strong, and capable of reproducing hand motions

小児用筋電義手のための倍力機構に関する研究

　筋電義手は，人間の筋肉から生じた微弱な電気信号を筋電センサーにより検知し,それをコントローラの入力信号として利用することで,人間が直感的にコントロールできる電動義手である.昨今,筋電義手の開発が盛んに行われており,高性能な筋電義手が既に市販されている.しかし,一般市場に流通している筋電義手の大半は，成人上肢切断者向けに開発されているものである.　しかしながら,上肢切断者の中には,先天的あるいは後天的に手を失った小児も存在している.小児上肢切断者の日常生活に役立つ筋電義手のハードウェアに関する設計要件としては軽量・小型・高出力を兼ね備えることである.ABS樹脂と小型のアクチュエータを使用することによる軽量な筋電義手はすでに存在している.また,3Dスキャナーを利用して小児の手の形取りを行い,自然な手の外観を再現する小型の筋電義手も実現されている.しかし,重量と空間に対する厳しい制限により,出力が弱い問題がある.　本研究の目的は,軽量・小型を兼ね備えるとともに,小児用筋電義手に実装可能な力増大機構（倍力機構）を開発することである.そこで筋電義手の重量と空間に対する制約条件を考慮したボールチェーン牽引倍力機構を開発した.従来のダイレクト駆動式筋電義手では5Nのピンチ力であったのに対し,この倍力機構が搭載された小児用筋電義手のピンチ力は14Nに達した.倍力機構の力学適応性を向上させるために,腱鞘機構を開発した.腱鞘機構を倍力機構と組み合わせることで,筋電義手の力学適応性が著しく向上した.最後に,筋電義手の四本指のMP関節の可動範囲を拡大して把持性能を向上させるために,アクチュエータを改良し,無限回転型ボールチェーン牽引腱鞘倍力機構を開発した.この機構は高出力,高い力学適応性を有した上で開き幅が拡大されたので,大きい物体を把持する際に良いパフォーマンスが期待される.　開発した三種類の倍力機構が搭載された筋電義手と従来のダイレクト駆動式筋電義手の性能を比較するために,3人の被験者でPick and Place実験を行った.開発された倍力機構を搭載することにより,従来のダイレクト駆動式筋電義手より高い把持性能を得たことを実験結果から証明できた.電気通信大学201

Biomechatronics: Harmonizing Mechatronic Systems with Human Beings

This eBook provides a comprehensive treatise on modern biomechatronic systems centred around human applications. A particular emphasis is given to exoskeleton designs for assistance and training with advanced interfaces in human-machine interaction. Some of these designs are validated with experimental results which the reader will find very informative as building-blocks for designing such systems. This eBook will be ideally suited to those researching in biomechatronic area with bio-feedback applications or those who are involved in high-end research on manmachine interfaces. This may also serve as a textbook for biomechatronic design at post-graduate level