EXTERNAL TEMPERATURE AND PULSE RATE SENSING AND TRANSMITTING DEVICE

• US 3,851,320 A
• Filed: 11/08/1973
• Issued: 11/26/1974
• Est. Priority Date: 11/08/1973
• Status: Expired due to Term

• Current Assignee: Joseph D. Dahl
• Original Assignee: Joseph D. Dahl
• Inventors: Dahl, Joseph D.
• Primary Examiner(s): Habecker, Thomas B.
• Application Number:
  US05/413,891
• Time in Patent Office: 383 Days
• Field of Search: 340/189M,208,195 331/65,66,117 336/134,83,30
• US Class Current: 340/870.17
• CPC Class Codes: A61B 5/0008 Temperature signals
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: G01K 1/024 for remote indication
• CPC Class Codes: Y10S 128/903 Radio telemetry

Abstract

A temperature and pulse rate sensing and transmitting device mounted onto the chest wall of a patient encapsulating a circuit comprising a blocking oscillator adapted to determine a specific R.F. transmission of a carrier frequency and embodying a thermal element having a linear variation as a function of temperature change to shift the blocking rate of said frequency to provide temperature readings and embodying an element to vary the inductance of the coil of said circuit as a function of the pulse rate of the patient to shift the internal blocking frequency with respect to a calibrated frequency to provide pulse rate readings, both readings to be received by a receiver embodying standard techniques such as to provide a digital readout.

Claims

1. A temperature and pulse rate sensing and transmitting device having in combination a housing of small thickness for attachment at one side thereof to the chest wall of a patient, a transistorized R.F. transmission circuit encapsulated within said housing, said circuit comprising a blocking oscillator circuit including an inductance coil and a variable capacitor, said coil and said capacitor being calibrated to transmit a specific carrier frequency to indicate a normal pulse rate, a metal plate member carried at the inner side of said one side of said housing in close proximity to said coil and vibrating in response to the pressure of the heartbeat of said patient varying the inductance of said coil responsive to changes in the rate of said heartbeat shifting said carrier frequency accordingly, said circuit including a blocking capacitor and a variable resistor, said capacitor and resistor being calibrated to have said circuit transmit a specific blocking rate to indicate a normal body temperature, a thermal resistance element in circuit with said variable resistor and blocking capacitor shifting said blocking rate in accordance with and in response to changes in body temperature, whereby shifts in said carrier frequency and in said blocking rate of the signals transmitted by said circuit indicate changes of pulse rate and body temperature.

2. The structure set forth in claim 1, wherein said one side of said housing and same metal plate member form a diaphragm sufficiently sensitive to vibrate in response to the vibration of the heartbeat of the patient.

3. The structure set forth in claim 1, wherein said housing comprises a chamber, a battery in said chamber energizing said circuit, said coil being disposed about said battery within said chamber, and said metal plate member vibrates freely within said chamber in close proximity to said coil.

4. The structure set forth in claim 1, including a resistor in circuit with said thermal resistor and emitter of the transistor of said circuit to prevent emitter degeneration to stabilize the same against temperature change.