Patent ID: 6025782
Filing Date: 2000-02-15
Classification: A61B,G08B

Abstract:
An apparatus for monitoring the presence of a person within a predefined space comprising:a. a flexible capacitance sensor, said sensor comprising a flexible substrate and a plurality of coplanar conductive elements, said conductive elements adhesively positioned in a spaced relationship on said flexible substrate;b. an electronic driver circuit, said driver circuit establishing a nominal voltage between said conductive elements of said capacitance sensor; andc. an electronic sensor circuit, said sensor circuit detecting capacitance changes within said capacitance sensor and generating an output signal having frequency variations corresponding to said capacitance changes, said sensor circuit positioned physically adjacent to said conductive elements of said capacitance sensor to minimize interfering effects from external electromagnetic fields, said capacitance changes serving to indicate the presence or absence of said person within said predefined space.