Patent ID: 6011477
Filing Date: 2000-01-04
Classification: A61B

Abstract:
An apparatus for monitoring respiration and movements of an infant positioned adjacent to a supporting platform, comprising:a first sensor positioned between the infant and the support platform, the first sensor not having a physical attachment to the infant and including a distributed inductance and distributed capacitance device formed as a radially wound spiral flat conductor strip that produces a uniform electric field for sensing the respiration and movements of the infant the first sensor further having an impedance that is a function of a frequency, the impedance having a maximum value when the frequency equals a resonant frequency of the first sensor, the resonant frequency varying as a function of the respiration and movements of the infant;an oscillator generating a signal having an operating frequency that substantially equals or is close to the resonant frequency of the first sensor;a high-impedance element coupling the signal from the oscillator to the first sensor, the high-impedance element and the first sensor forming a voltage divider that produces from the signal a sensor voltage that is proportional to the impedance of the first sensor and is, therefore, responsive to the respiration and movements of the infant;a detector extracting from the sensor voltage a first signal representative of the respiration and movements of the infant;a controller receiving the first signal and including a band-pass filtering function to extract from the first signal a respiration-related signal and a band-stop filtering function to extract from the first signal a movement-related signal; anda signal processor processing at least one of the respiration-related signal and the movement-related signal to generate an alarm signal.