Apparatus for remote temperature reading

• US 4,399,441 A
• Filed: 01/19/1981
• Issued: 08/16/1983
• Est. Priority Date: 01/25/1980
• Status: Expired due to Fees

• Current Assignee: Unisearch Limited 221-227 Anzac Parade Kensington New South Wales Australia A Company Limited By Guarantee of New South Wales
• Original Assignee: Unisearch Limited (University Of New South Wales)
• Inventors: Vaughan, Richard, Cole, Peter H.
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US06/226,518
• Time in Patent Office: 939 Days
• Field of Search: 343/6.5 SS, 128/736
• US Class Current: 342/50
• CPC Class Codes: A61K 38/00 Medicinal preparations containing peptides peptides containing beta-lactam rings A61K31/00; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, A61K31/00; ergot alkaloids of the cyclic peptide type A61K31/48; containing macromolecular compounds having statistically distributed amino acid units A61K31/74; medicinal preparations containing antigens or antibodies A61K39/00; medicinal preparations characterised by the non-active ingredients, e.g. peptides as drug carriers, A61K47/00
• CPC Class Codes: B61L 25/045 using reradiating tags
• CPC Class Codes: G01K 1/024 for remote indication
• CPC Class Codes: G01K 11/24 of the velocity of propagation of sound
• CPC Class Codes: G01S 13/765 with exchange of information between interrogator and responder
• CPC Class Codes: G06K 19/0675 the resonating marks being of the surface acoustic wave [SAW] kind SAW devices per se H03H9/64

Abstract

An apparatus for remote temperature reading particularly for the reading of the temperature of an article or animal at a distance by means of an electromagnetically interrogatable label attached to or implanted in the article or animal the label being constructed to be capable of receiving an electromagnetic signal from a transmitter, converting the signal to a surface acoustic wave, passing the wave over a path on the label, reconverting the surface acoustic wave to an electromagnetic signal and retransmitting it to a receiver. The path of the surface acoustic wave is of a material such that the time of travel of the surface acoustic wave over the path is a function of the temperature of the path and thus of the label. The receiver is constructed to measure the time interval between electromagnetic signals produced by the passage of the surface acoustic wave past a transducer or transducers in the path and thereby provide an output indicative of the temperature of the environment of the label. It is preferred that the label includes a plurality of transducers at coded locations along the path arranged for retransmitting to the receiver a coded sequence of electromagnetic signals indicative of an article or animal to which the label is affixed or in which it is implanted in the manner described in U.S. Pat. No. 3,706,094.

Claims

1. Apparatus for remote temperature reading comprising transmitter means for transmitting electro-magnetic signals, label means adapted for attachment to or implantation in an article or animal for receiving a signal transmitted from said transmitter means and for retransmitting a reply, and receiver means for receiving and processing the reply;

said label means including antenna means for receiving said transmitted signal, transducer means for converting said electromagnetic signal to a surface acoustic wave, a path on said label over which said surface acoustic wave travels, the time of travel of said surface acoustic wave over said path being a function of the temperature of the path, the same or further transducer means being arranged to convert said surface acoustic wave to a first electromagnetic signal after it has travelled over a first part of said path and to feed said signal to said antenna means for retransmission to said receiver means and thereafter to convert said surface acoustic wave to a second electromagnetic signal after it has travelled over a second part of said path and to feed said second electromagnetic signal to said antenna means for retransmission to said receiver means, said receiver means including circuitry for measuring the time interval between said first and second electromagnetic signals resulting from the passage of said surface acoustic wave over said path and for providing from said measured time interval an output indicative of the temperature of the environment of the label means.

2. Apparatus as claimed in claim 1 wherein said label means includes a plurality of transducer means at coded locations along said path arranged for retransmitting to said receiver means a coded sequence of electromagnetic signals indicative of an article or an animal to which said label is affixed or in which it is implanted.

3. Apparatus as claimed in claim 1 or 2 wherein the transmitter means is constructed and arranged to transmit electromagnetic signals in the form of pulses of radio frequency energy and the receiver is constructed and arranged to receive reply signals in this form and to measure the time interval between said first and second electromagnetic signals by measurement of the change in phase between said signals resulting from the passage of said surface acoustic wave over said path.

4. Apparatus as claimed in claim 1 wherein the said path is closed on itself and a single transducer means is included in said path.

5. Apparatus as claimed in claim 1 wherein a single transducer means is provided in said path having reflector means provided on each side of it, said reflector means being at different distances from the transducer means, said path extending between said reflector means.