Tomoyuki Yambe

Experimental and clinical evaluation of a sack-type ventricular assist device and drive system

A newly designed ventricular assist device and driving system, including an automatic control system, is presented. The blood-contacting surfaces of the blood pump are coated with either Cardiothane or Cardiomat. The system was tested in experiments on goats, whereby only one of fifteen animals showed sudden thrombus formation after 34 pumping days. The system was also applied in three clinical cases for durations of 18 h, 2 days, and 5 days. In two of the cases, weaning could not be performed because of continued bleeding, and the other patient is still alive. No gross findings of thrombus formation were observed in any of the cases, except for a thin circular thrombus at the junction of the connectors and the sack of the blood pump.

High-Tech Equipment for Moxibustion in Modern Medicine

Japan is a super-aging society; year after year, the number of persons older than 65 years of age increases. Because they are frail, elderly persons require treatment methods that best suit their condition. Traditional medicine, which has been handed down and culled throughout history, is one such candidate treatment. Until recently in Japan, moxibustion therapy was provided in most households (Yamaoka, 2001). In recent years, hyperthermia treatment has spread widely in the field of orthopaedics, rehabilitation, and cancer treatment. Typically, medical sites require safe, sanitary treatment methods.

BIOLOGICAL EFFECTS OF THE ARTIFICIAL ANAL SPHINCTER IN THE GOAT MODEL

Artificial anal sphincters could provide an alternative solution for severe anal incontinence when conventional surgical methods are not possible. We have created an artificial anal sphincter using a shape memory alloy (SMA) and evaluated its validity. The aim of this study was to determine the biological effects and safety after implantation of the SMA artificial anal sphincter in an animal model. The artificial anal sphincter consists of two all-round SMA plates as the main functional parts which perform two basic functions: occlusion at normal body temperature and release upon heating. The SMA artificial anal sphincter was implanted into three female goats under anesthesia. Blood was collected postoperatively from the jugular vein on days 1 and 4, at week 1, and months 1, 2, and 3, and biochemical parameters were examined. Biochemical test results were within normal limits during the 3-month study period. All biochemical measurements of organ function remained within normal range. The results demonstrated that the SMA artificial anal sphincter caused no significant failure of liver, renal, autonomic or digestive functions or damage to smooth muscle. This long-term animal experiment supported the concept and design of implantation with an SMA artificial anal sphincter, and the results demonstrate very good biocompatibility and effective system performance.