Advantages of externally powered prosthesis with feedback system using pseudo-cineplasty.

Externally powered upper-limb prostheses are difficult to use because of the lack of sensory feedback. Neuroprostheses have recently been developed for people with upper-limb amputation but are complicated, expensive, and still developing. We therefore designed a simple system by combining pseudo-cineplasty with extended physiological proprioception to provide sensory feedback to the body. We penetrated the palmaris longus tendon percutaneously with a metal ring, similar to that used in body piercing, in a nondisabled subject as a pseudo-cineplasty. The tendon and ring were connected to the system, and a sensory feedback experiment was performed. We investigated the ability of the user to determine the size of an object grasped by the prosthetic hand without visual information. The subject could distinguish between large and small objects with 100% accuracy and between small, medium, and large objects with 80% accuracy. In pseudo-cineplasty, control and sensory feedback are natural because the prosthetic hand is controlled by muscle contraction. Tension transmitted from the prosthetic hand is sensed via muscle spindles and skin sensors. This technique allows only partial sensory feedback but appears to offer several advantages over other human-machine interfaces.

Development of a triage engine enabling behavior recognition and lethal arrhythmia detection for remote health care system.

For ubiquitous health care systems which continuously monitor a person's vital signs such as electrocardiogram (ECG), body surface temperature and three-dimensional (3D) acceleration by wireless, it is important to accurately detect the occurrence of an abnormal event in the data and immediately inform a medical doctor of its detail. In this paper, we introduce a remote health care system, which is composed of a wireless vital sensor, multiple receivers and a triage engine installed in a desktop personal computer (PC). The middleware installed in the receiver, which was developed in C++, supports reliable data handling of vital data to the ethernet port. On the other hand, the human interface of the triage engine, which was developed in JAVA, shows graphics on his/her ECG data, 3D acceleration data, body surface temperature data and behavior status in the display of the desktop PC and sends an urgent e-mail containing the display data to a pre-registered medical doctor when it detects the occurrence of an abnormal event. In the triage engine, the lethal arrhythmia detection algorithm based on short time Fourier transform (STFT) analysis can achieve 100 % sensitivity and 99.99 % specificity, and the behavior recognition algorithm based on the combination of the nearest neighbor method and the Naive Bayes method can achieve more than 71 % classification accuracy.

Clinical tests and evaluations of a wireless ECG sensor for realization of ubiquitous health care systems.

This paper introduces the concept of an online medical diagnosis system for ubiquitous health care using a wireless ECG sensor. To confirm the feasibility ofthe system, we conducted clinical tests by 67 subjects with a wireless ECG sensor and a Holter ECG monitor simultaneously for comparison purpose. We made five types of evaluations such as analyses on data loss rate, burst data loss length, ECG waveforms comparison, normalized cross-correlation and heart rate variability (HRV) by RR50. The results show that, as long as the sensed data are successfully received at a receiver, the wireless ECG sensor has a comparable performance with the Holter ECG monitor.

A receiver diversity technique for ensuring high reliability of wireless vital data gathering in hospital rooms.

Sensing and wireless technologies have made remarkable advance recently, so wireless vital sensors for medical use, which are light-weight but accurate, have been commercially available. However, because of the low reliability of the wireless data transmission, sensed vital data are often lost in the wireless channel and this is a fatal drawback of the devices for continuous monitoring of patients in hospitals. This paper investigates the effect of using multiple receivers (receiver diversity technique) on the improvement of data loss rate for wireless vital data gathering. Experiments with a wireless vital sensor in hospital rooms reveal that putting receivers to higher positions such as ceiling is advantageous and the use of three receivers can sufficiently improve the data loss rate as compared with the use of a single receiver.