Implantable inductively programmed temperature sensing transponder

• US 20050169345A1
• Filed: 03/18/2005
• Published: 08/04/2005
• Est. Priority Date: 02/11/2000
• Status: Active Grant

• Current Assignee: David Ellwood, Donald J. Urbas, Eric B. Weddington
• Original Assignee: David Ellwood, Donald J. Urbas, Eric B. Weddington
• Inventors: Weddington, Eric B., Ellwood, David, Urbas, Donald J.
• Granted Patent: US 7,052,178 B2
• Time in Patent Office: Days
• US Class Current: 374/100
• CPC Class Codes: A01K 11/006 Automatic identification systems for animals, e.g. electronic devices, transponders for animals identification systems for access to feeding pens A01K1/0209; ear tags with electronic identification means A01K11/004
• CPC Class Codes: A61B 5/0008 Temperature signals
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: G01K 1/024 for remote indication
• CPC Class Codes: G01K 13/20 Clinical contact thermometers for use with humans or animals
• CPC Class Codes: G06K 19/0717 the sensor being capable of sensing environmental conditions such as temperature history or pressure
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs

Abstract

A method for determining temperature from a transponder utilizing a thermistor and a running counter comprises providing a running count which varies as a function of temperature; latching the count at predetermined time intervals; determining the difference between the values of successive latched counts; aggregating the differences; determining the total elapsed time between a first latched count and a last latched count; dividing the aggregate by the total time to obtain a frequency; and converting the frequency to a temperature based upon the temperature frequency characteristics of the thermistor.

Claims

1. A method for determining temperature from a transponder utilizing a thermistor and a running counter comprising the steps of:

providing a running count which varies as a function of temperature;

latching the count at predetermined time intervals;

determining the difference between the values of successive latched counts;

aggregating the differences;

determining the total elapsed time between a first latched count and a last latched count;

dividing the aggregate by the total time to obtain a frequency; and

converting the frequency to a temperature based upon the temperature frequency characteristics of the thermistor.

2. The method of claim 1, comprising the step of determining the difference between the smallest difference obtained and the largest difference obtained and determining whether or not the second difference falls within a range;

beginning the process over if the difference does not fall within the range.

3. The method of claim 2, further comprising repeating the steps to obtain a second temperature value;

comparing a first temperature value to the second temperature value; and

outputting the temperature as a temperature value if the first temperature value is equal to the second temperature value.