Blood circulation monitoring under anaesthesia using oral photodetector - recommences measurement cycle whenever pulsation volume of tongue , deduced by reflectometry, departs significantly from initial value.

摘要

The sensor (1) inserted under the tongue (Z) contains a diode (3) emitting pref. in the 805 nm wavelength region, and a photodiode (4), both in close proximity to windows (5,6) in the uppermost wall (7) of its housing (2). Light is reflected from the tongue (Z) while the latter is compressed by a pneumatic or hydraulic cushion (9) linked to a pump (10) and sphygmomanometer (11). A pulse ratemeter (12) giving audible and visual indications is used with an oscilloscope (13). ADVANTAGE - Errors due to blood-vessel vol. and body temp. regulatory mechanism, variable tissue O2 saturation, and interference from ambient light are avoided.