|Budget Amount *help
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1994 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1993 : ¥1,600,000 (Direct Cost : ¥1,600,000)
The aim of this research is to develop a new intelligent system for the Percutaneous Transluminal Coronary angioplasty (PTCA). The following is the basic concept. The system is controlled by a microcomputer which determines the amount of water to be infused into the balloon and orders the infusing unit to do so. At the same time, the computer surveys the pressure in the dilating balloon and calculates the viscoelastic parameters of the arterial wall around the balloon. The dilatation is continued until those parameters reach the level at which the dilatation is successfully and safely completed. As soon as those parameters come near the level at which the dilatation is dangerous, the procedure is immediately abandoned.
A new computerized control system that infuses water into the dilating balloon, measures pressures and calculates the viscoelastic parameters of the arterial wall was assembled. The infusing system has a long narrow tubing, which makes the viscotic resistance of the whole
system very big. Therefore, there is an intricate time difference between pressures measured in the infusing unit and the dilating balloon. To calculate the exact pressure using the pressure values in the infusing unit on a realtime basis, a linear electric circuit model with an observer system was introduced. A theoretical analysis on this model was meticulously performed. The predicted pressure values in the balloon by the observer were confirmed to be well consistent with the real data. Using this model and the observer, the theoretical calculation on how much the equilibrium pressure in the balloon would be when some amount of water was infused, was studied. Three methods were developed. Each of those predicted the final pressure values, all of which were confirmed to be consistent with the previously obtained data. However, there remained a few problems to be solved to bring those methods immediately clinically applicable.
This study has paved a way to establish a physical analysis of the PTCA procedure, which will make this procedure far effective and safe.