頭の電気容量脈波及びインピーダンス脈波について

CRANIAL CAPACITO-SPHYGMOGRAPHY AND IMPEDANCE PLETEYSMOGRAPHY

緒言

　脳の血液循環の状態を知る方法は，古来多くの学者により研究され種々の方法が考案されている。即ち，Forbes^1）（1928）により始められた頭窓法，脳血管灌流法（Dixon and Halliburton^2）1910,Brown^3）1916,etc）或は熱液流計（Rein^4）1928），電磁流速計（Kolin^5）1936），熱電対（Gi-bbs^6）1933）等を使用する方法，髄液圧の変動を見る方法（原田^7）1937）等があり，又近くは，Kety and Schmidt^8）により始められたN₂0法（1942），Davies and Brink^9）により始められたPolarography （1942），David H．Ingvarによつて始められた所謂Ingvar's method^10）（1956）がある。殊にN₂O法は広く行われ，わが国でも相沢^11）を初め各所で行われており，脳循環の研究に寄与している所は大きい。

　以上のように多数の方法があるが，正確であり，且つ臨床的にも応用できるものは，N₂O法のみと考えてよかろう。しかし，この方法の操作はかなり面倒であり，又短時間内の脳循環の変動を知る目的には不適である。

Various methods to establish the cerebral circulation have been made by many investi-gators, but the plethysmographical method has been rarely made and not yet clearly es-tablished.

This investigation was carried out for the purpose of detecting the applicability of ca-pacito-sphygmography and impedance plethy-smography on the study of cerebral circulati-on.

(1) Capacito-sphygmography A very sensitive capacito-sphygmograph was designed for my purpose. But it showed that when the electrodes were placed,directly upon the skull bone, no intra-cranial pulsati-on could be detected. Therefore, I concluded that, this device was not suitable for the estimation of cerebral circulation.

(2) Impedance Plethysmography An Impedance Plethysmograph, utilizing a 20 K. C., A. C., bridge, was designed and pro-ved, in experimental dogs, to be able to pick up the intra-cranial pulsation by either a bo-ne-lead or an intra-cranial lead.Then the effects of some vaso-dilatory agents and cer-vical sympathetic stimulation upon the con-tinuously recorded intra-cranial pulse-wave were detected.

Results of this experiment showed that, this method would be applicable for my pur-pose.