| 摘要 |
<p>PURPOSE:To estimate the presence and position of the lesion region in the cranium based on abnormal blood flow noise with high accuracy, by analyzing the difference data calculated by subtracting the data at the time of a low blood flow speed from the data at the time of the high blood flow speed detected from a blood flow noise detection means. CONSTITUTION:Vortex flow sound and turblent flow sound are hard to generate in the vicinity of the point A of time when the blood flow speed V in the cranium is slow but easy generate in the vicinity of the point B of time when the blood flow speed V is high and the power of abnormal blood flow noise increases. However, unnecessary noise other than blood flow noise is uniformly generated at a certain level regardless of the point A of time when the blood flow speed V is low and the point B of time when the blood flow speed V is high and penetrates in a blood flow noise detection means 6. Herein, by subtracting the unnecessary noise containing much abnormal blood flow noise in the vicinity of the point B of time when the blood flow speed V in the cranium is high from the unnecessary noise in the vicinity of the point A of time when the blood flow speed V is slow, the abnormal blood flow noise due to the vortex flow and the turblent flow is extracted. When this noise is analyzed, the presence of a cerebral aneurysm can be easily detected. Since the sound generated from blood vessel lesion such as the cerebral aneurysm can be easily discriminated from unnecessary noises, the accuracy and reliability of diagnosis are enhanced.</p> |
