AMBIENT COMPENSATED TEMPERATURE RESPONSIVE DEVICE

• US 3,781,837 A
• Filed: 07/08/1971
• Issued: 12/25/1973
• Est. Priority Date: 07/08/1971
• Status: Expired due to Term

• Current Assignee: Robert L. Caroon, Thomas W. Anderson
• Original Assignee: Robert L. Caroon, Thomas W. Anderson
• Inventors: Anderson, Thomas W., Caroon, Robert L.
• Primary Examiner(s): Caldwell, John W.
• Assistant Examiner(s): Partridge, Scott P.
• Application Number:
  US05/160,612
• Time in Patent Office: 901 Days
• Field of Search: 340/227,228,233 128/2H,399
• US Class Current: 600/549
• CPC Class Codes: A01K 29/005 Monitoring or measuring activity, e.g. detecting heat or mating
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61D 17/00 Devices for indicating trouble during labour of animals ; Methods or instruments for detecting pregnancy-related states of animals monitoring or measuring activity of animals A01K29/005
• CPC Class Codes: G01K 1/024 for remote indication

Abstract

A temperature responsive device is provided for use with cattle, and similar livestock, to furnish signals when the measured body temperature of the animal exceeds predetermined limits which are indicative of infection or disease within the animal. A small electronic package is conveniently fastened about the animal'"'"''"'"'s neck and is connected to a thermistor sensing element implanted in one of the outer ear canals of the animal. The electronic package is provided with a temperature compensated amplifier and includes means compensating for changes in body temperature due to changes in ambient temperature, such that false signals will not be generated by the device. When the amplifier output reaches a predetermined threshold level, a signal device, such as an audio alarm, is energized to indicate that the animal should receive immediate diagnosis or treatment.

Claims

1. A device for indicating abnormal health conditions in a living body as a function of body temperature where the temperature of the living body in a healthy condition is a known function of ambient temperature over a teMperature range to which the living body is exposed, said device comprising first circuit means for producing output signals representative of said abnormal health conditions, second circuit means including first and second temperature sensing means for comparing the temperature of the living body with the temperature of the ambient surrounding the living body to enable said first circuit means to produce said output signals when said sensed body temperature differs from said known function by predetermined temperature values, said first temperature sensing means being in close heat transfer relationship to the living body for sensing the temperature thereof, said second temperature sensing means sensing the ambient temperatures surrounding the living body.

2. The device set forth in claim 1 wherein said first temperature sensing means includes a first temperature sensitive thermistor fitted closely to the living body.

3. The device set forth in claim 2 wherein said second temperature sensing means includes a second temperature sensitive thermistor exposed to the ambient temperature.

4. The device set forth in claim 1 wherein said first and second temperature sensing means include first and second temperature variable resistance means fitted closely to the living body and exposed to the ambient respectively, the value of said resistance means varying substantially with changes in temperature.

5. The device set forth in claim 4 wherein said second circuit means comprises a bridge circuit connected across a source of voltage, said first and second temperature variable resistance means being in different legs of said bridge circuit, said first circuit means including first amplifier means connected across the nodes of said bridge circuit for producing said output signals when the bridge is in an unbalanced condition.

6. The device set forth in claim 5 wherein said first and second temperature variable resistance means include first and second temperature sensitive thermistors.

7. The device set forth in claim 5 wherein said second circuit means includes means for inserting said second temperature variable resistance means into said second leg of said bridge circuit only when said ambient temperature is greater than a predetermined reference temperature.

8. The device set forth in claim 7 wherein said amplifier means connected to said bridge circuit provides said output signals in response to imbalance of the bridge circuit.

9. The device set forth in claim 8 wherein said amplifier means includes a differential amplifier connected across the nodes of said bridge circuit.

10. The device set forth in claim 7 wherein said means for inserting said second variable resistance means includes diode means which is reverse biased unless said ambient temperature is greater than said predetermined reference temperature.