A photoelectric diameter gauge utilizing the image sensor

We have designed and constructed a blood vessel diameter gauge, utilizing a high resolving power and stability of the image sensor which has become of major interest lately as a new photoelectric transducer. The distinct feature of the gauge is summarized as follows. (1) Contact-free measurements of blood vessel diameter (1–14 mm) are possible. (2) The cuff-type probe is small in size and easy to put to use. (3) The lightguide consisting of optical fibers makes incident light cold. (4) The resolving power of the gauge is 28 m in principle. (5) The frequency response of the gauge is flat up to 100 Hz. A few results of its preliminary application to in vitro and in vivo experiments are also demonstrated.