光トランスデューサを用いた胸壁面振動検出システムの開発

抄録

As a new diagnostic technique for heart diseases, a two-dimensional mapping system of body surface microvibration due to cardiac cycle has been designed and built as a trial. The system is composed of an optical fiber transducer and a microprocessor-equipped display system.
The optical fiber transducer is composed of three parts : (1) He-Ne laser light source, (2) phototransistor sensor and (3) optical fibers which guide the light from source to object and from object to detector. On the tip of the transducer, optical fibers are arranged in a honeycomb lattice shape with proper separations so that the intensity of the reflected light will be proportional to the displacement of the object, and the surface angle to the light axis can be compensated. In addition, the difference of surface reflectivity is also compensated using the light intensity, detected by another optical fiber arranged at a relatively far distance.
The data processing unit of body surface cardiac potential mapping is used for A/D conversion, storage and display of the data.
The preliminary experiments on five healthy male subjects suggested that the normal precordial vibration pattern accompanied a large retraction during systolic period at the right parasternal area.