Japan Association for the Advancement of Medical Equipment

Cellular Therapy Products, Gene Therapy Products, and Cosmetics . Points of the amendment are to Revise medical device regulations based

Background: Thirst is a common and troublesome symptom for patients with congestive heart failure (CHF). The determinants of thirst have important implications for guiding clinical management. Orthostatic stress (OS) is unavoidable for CHF patients. We hypothesized that OS may be one of the crucial factors to cause thirst in CHF. This study investigated thirst responses to OS in sham and CHF rats. Methods: Coronary artery occlusion in 8 weeks old rats were raised for 12 weeks to cause CHF. Ether sham or CHF rats were moved from standard cage to a high roof cage (H=33cm) where rats had to stand up to get food or water (defined as OS). A real‐time monitoring system was used to record water consumption (implied as thirst) of individual animals. Results: In the standard cage, there was no significant difference of daily water consumption between sham and CHF rats (73±12 vs.66±5.9 g/Kg/day, p>0.05). But CHF rats prolonged drinking interval (1.0±0.21 vs. 1.5 ±0.22 hr, p<0.05). Response to OS, sham rats decreased daily water intake by 17.5% (p<0.01); CHF rats significantly increased by 13.3% (p<0.05). Conclusion: The results suggested that response to osmotic changes in CHF rats were attenuated. In response to OS, sham rats may decrease the water excretion by nurohumoral mechanisms to compensate circulatory volume; however, CHF rats increase water ingestion due to great thirst.

We have developed the magnetically suspended artificial hearts with a diagonal-flow pump. The magnetic bearing for this pump has consists of four stators, for permanent magnets and a rotor. In this study, optimal design method of the magnetic bearing for diagonal-flow blood pump has been developed. This method includes the genetic algorithm(GA), which based on the evolution of living organisms. In this paper, three types of magnetic bearing that have different target attractive force is designed with the proposed method. Size of the designed magnetic bearing were 48×60[mm], 60×69[mm], 77×76[mm], respectively. Optimal design solutions that minimize the power consumption could be obtained. As a next step, the suitable model will be defined by using the finite element method