Thermal protective circuit for a hyperemia-inducing physiological sensor

US4334541A · kind A · utility

Assignee

• Hellige GmbH · DE

Inventors

• Helmut Leist · Freiburg im Breisgau, DE
• Georg J. Ullrich · Freiburg im Breisgau, DE

Key dates

• Filing date: Mar 17, 1980
• Grant date: Jun 15, 1982
• Expiry date: Mar 17, 2000

Classification

• Technology area (CPC G): Physics
• CPC primary: G12B7/00
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A sensor for transcutaneous measurement of physiological phenomena of living tissues is provided with a thermostatically-controlled electric heater. The purpose of the heater is to induce local hyperemia to enable operation of the sensor. The heater is thermostatically controlled. An independent temperature sensor is provided to disable the heater in the event of catastrophic failure of the thermostat circuit.