Showing papers by "Takashi Yamane published in 2003"

Axial type self-bearing motor for axial flow blood pump

Abstract: An axial self-bearing motor is proposed which can drive an axial blood pump without physical contact. It is a functional combination of the bi-directional disc motor and the axial active magnetic bearing, where it actively controls single degree-of-freedom motion, while other motions such as lateral vibration are passively stable. For application to a blood pump, the proposed self-bearing motor has the advantages of simple structure and small size. Through the finite element method (FEM) analysis and the experimental test, its good feasibility is verified. Finally, the axial flow pump is fabricated using the developed magnetically suspended motor. The pump test is carried out and the results are discussed in detail.

Development of built-in type and noninvasive sensor systems for smart artificial heart.

Abstract: It is very important to grasp the artificial heart condition and the physiologic conditions for the implantable artificial heart. In our laboratory, a smart artificial heart (SAH) has been proposed and developed. An SAH is an artificial heart with a noninvasive sensor; it is a sensorized and intelligent artificial heart for safe and effective treatment. In this study, the following sensor systems for SAH are described: noninvasive blood temperature sensor system, noninvasive blood pressure sensor system, and noninvasive small blood flow sensor system. These noninvasive sensor systems are integrated and included around the artificial heart to evaluate these sensor systems for SAH by the mockup experiments and the animal experiments. The blood temperature could be measured stably by the temperature sensor system. Aortic pressure was estimated, and sucking condition was detected by the pressure sensor system. The blood flow was measured by the flow meter system within 10% error. As a result of these experiments, we confirmed the effectiveness of the sensor systems for SAH.

Tsukuba Remote Monitoring System for Continuous‐Flow Artificial Heart

Abstract: In order to make long-term medical treatment with the use of an artificial heart effective, we developed the Tsukuba remote monitoring system, which enables medical staff to manage the physiological condition of patients and the driving condition of the artificial heart at anytime from a remote place. This remote monitoring system has three functions: first, a remote monitoring function, which enables medical staff to monitor measured data from a remote place anytime by using not only a personal computer but also a cellular phone; second, an analyzing function, which estimates the unmeasured physiological behavior in the body based on a mathematical physiological model; and third, a warning function, which detects physiological problems and malfunction of the artificial heart by applying the if-then rule and sends a warning message to the medical staff. As a result of applying this system to animal experiments, we have confirmed the effectiveness of the proposed system.

Improvement of anti-wear function of pivot bearing for a centrifugal blood pump. (Part 1): Wear mechanisms in spinning motion

Abstract: How the contact areas of the plates of ultra-high-molecular weight polyethylene (UHMWPE) and the same material but cast in advance with γ-ray on which an alumina ceramic hemisphere, 3 mm diameter, is pressed at a load of 10 N, change their profiles with load time, are studied experimentally in creep tests and spinning contact wear tests. The spinning contact wear tests are carried out on condition that the alumina ceramic hemisphere revolves at 2,000 rpm. It is found that the profile of the contact area of UHMWPE, unilaterally deformed and brought into a hemisphere concave according to the shape of the hard male pivot during load test, turns out to be a pattern of letter W when the elastic recovery completes after load is removed.