US 3,937,214 AGranted

Electromedical patient monitoring system

OwnerThomas B. Hutchins, IVinventor

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Abstract

An electromedical patient monitoring system having a minimum likelihood of electrical injury to a patient is provided. Signals from a body-contacting sensor are amplified and processed by self-contained, battery powered apparatus for display by an electrical monitor, such as a recorder. In a preferred embodiment, the apparatus includes an input circuit operatively connected to the sensor and including an AC amplifier. The output of the amplifier is inductively coupled to a synchronous detector, part of an output circuit operatively connected to the monitor. Operating power for both the amplifier and detector is derived from a battery-powered audio oscillator to which the input and output circuits are inductively coupled. Thus, the apparatus provides DC isolation of the sensor from both the monitor and from the power source for the apparatus. In addition, the apparatus includes provision for inductively coupling a portion of the oscillator output to an excitor circuit for a sensor of a type requiring excitation by electrical oscillations.

Claims2

Dependent claims

In a system comprising a body-contacting-type electromedical sensor for providing body-condition-related information, said sensor having power input means requiring AC excitation, and an electrical monitor for displaying or recording the information, improved apparatus for transmitting said information unidirectionally between said sensor and said monitor, comprising

a battery powerable oscillator,
excitor circuit means inductively coupled to said oscillator for supplying electrical AC excitation to said sensor's power input means,
an amplifier operatively connected to said sensor for receiving information therefrom and for unidirectionally transmitting such information,
powering circuit means inductively coupled to said oscillator for supplying operating power to said amplifier,
a synchronous detector inductively coupled to said amplifier for processing information received from said amplifier, and for supplying it to said monitor,
detector energizing means inductively coupled to said oscillator for energizing said detector in synchronization with the AC excitation supplied to said sensor,
first inductive coupling means inductively coupling said excitor circuit means, powering circuit means, and detector energizing means with said oscillator, and
second inductive coupling means coupling said amplifier with said synchronous detector,
said first and second inductive coupling means providing the sole electrical couplings between said oscillator, amplifier, and synchronous detector.

6 more elements

Dependencies are inferred from the claim text.