US3872728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic temperature measuring instrument
Assignee: Individual
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Filing: 1972-10-10
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Granted: 1975-03-25
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Expires: 1992-10-10
Abstract
Abstract A clinical thermometer which includes a temperature detecting probe for insertion into the body of the patient, and a display unit for indicating the temperature being measured, preferably housed in a single, self-contained, battery-powered unit. The unit includes novel circuitry whereby calibration and readiness for use may be indicated, and whereby the temperature may be displayed only upon achievement of the maximum temperature detected in the patient, whereupon such maximum reading will remain on display until intentionally removed. In its batterypowered form, complete portability of the unit can be achieved and a great number of determinations can be made without sacrifice of accuracy before battery replacement is indicated. To accomplish the foregoing purposes, a nematic or liquid crystal display is used for minimum current consumption and high resistance circuit components are carefully selected for this purpose. A rate of temperature increase or differentiator circuit is provided and a feedback circuit is provided to insure that power supply voltage variations do not affect the accuracy of temperature determinations. Preferably, an oscillator having a frequency determined by the temperature of the patient emits pulses at a rate proportional to the temperature, the number of these pulses occurring during elapse of an accurately predetermined, constant time is counted, and the number of pulses occurring in this time is digitally displayed as the temperature. The unit also preferably includes a novel dispenser containing a number of novel probe sheaths which are made by a method described herein.
Inventors
- 👤 Michael F Joyce
- 👤 George M Balmes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:04
CPC Classifications
G; G01; G01K; G01K7/00; G01K7/16; G01K7/18; G01K7/20; G01K7/203; G01K13/00; G01K13/20
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
242 words
A portable, battery-powered clinical thermometer apparatus adapted for repeated measurement and display of the temperature of a patient, said apparatus comprising, in combination, temperature detecting means including a resistor having substantialy the same change of resistance for each unit of temperature change, control signal generating means for generating a control signal having a magnitude which is a function of the resistance of said temperature detecting means, pulse generating means for generating a plurality of discrete electrical pulses at a rate proportional to the magnitude of said control signal, means for counting the number of said pulses occurring within a predetermined time, display means for displaying the number of said pulses counted during said predetermined time, rate detecting means coupled to said control signal generating means and independent of said pulse generating means and said counting means for detecting the instantaneous rate at which the temperature measured by said temperature detecting means is changIng in response only to said control signal generating means, and display control means coupled between said rate detecting means and said display means for rendering said display means operative in response to said rate detecting means only when said instantaneous rate of temperature change reaches a predetermined value, whereby the number of pulses occurring and being counted during said predetermined time bears a proportional and substantially linear relation to the resistance of said temperature response means and the number of pulses displayed indicates the true temperature of the patient.
Claim 2
Dependent Claim
242 words
A portable, battery-powered clinical thermometer apparatus adapted for repeated measurement and display of the temperature of a patient, said apparatus comprising, in combination, temperature detecting means including a resistor having substantialy the same change of resistance for each unit of temperature change, control signal generating means for generating a control signal having a magnitude which is a function of the resistance of said temperature detecting means, pulse generating means for generating a plurality of discrete electrical pulses at a rate proportional to the magnitude of said control signal, means for counting the number of said pulses occurring within a predetermined time, display means for displaying the number of said pulses counted during said predetermined time, rate detecting means coupled to said control signal generating means and independent of said pulse generating means and said counting means for detecting the instantaneous rate at which the temperature measured by said temperature detecting means is changIng in response only to said control signal generating means, and display control means coupled between said rate detecting means and said display means for rendering said display means operative in response to said rate detecting means only when said instantaneous rate of temperature change reaches a predetermined value, whereby the number of pulses occurring and being counted during said predetermined time bears a proportional and substantially linear relation to the resistance of said temperature response means and the number of pulses displayed indicates the true temperature of the patient.
Claim 3
Dependent Claim
64 words
An apparatus as defined in claim 1 wherein said means for generating said discrete pulses includes an oscillator having a frequency which is variable in proportion to the magnitude of said control signal, said oscillator having in the frequency-determining portion thereof a capacitor and variable resistance means in the form of a transistor having a conductivity controlled as a function of said control signal.
Claim 4
Dependent Claim
23 words
An apparatus as defined in claim 1 which additionally includes means in the form of a free-running multivibrator for establishing said predetermined time.
Claim 5
Dependent Claim
55 words
An apparatus as defined in claim 1 which additionally includes means for repeatedly establishing a constant time period, means for enabling said counting means repeatedly to initiate counting with the beginning of each of said constant time periods, whereby each pulse count accurately reflects the count of all pulses occurring during said entire time period.
Claim 6
Dependent Claim
86 words
An apparatus as defined in claim 4 wherein said means for establishing said predetermined constant time period is a multivibrator, and which further comprises a JK flip-flop coupled to said multivibrator, and wherein said rate change detecting means is coupled to the K terminal of said flip-flop, whereby, upon detection of said predetermined value of said rate of change, said flip-flop will be preconditioned to remain in one state upon occurrence of the next succeeding signal edge and whereby said count may be ''''locked'''' for display.
Claim 7
Dependent Claim
24 words
An apparatus as defined in claim 5 wherein means are provided for preventing further counting or resetting of counters when said display is enabled.
Claim 8
Dependent Claim
46 words
An apparatus as defined in claim 1 wherein said means for displaying the number of pulses counted during said predetermined time is in the form of nematic crystal display, whereby said instrument may display a reading without the energy consumption necessary to illuminate a display area.
Claim 9
Dependent Claim
51 words
An apparatus according to claim 1 wherein said temperature responsive means is in the form of a probe and wherein said resistor is disposed in intimate heat-exchange relation with the walls of said probe and arranged within said probe so as to lie along both substantial axial and circumferential portions thereof.
Claim 10
Dependent Claim
38 words
An apparatus as defined in claim 1 wherein said temperature responsive means is in the form of a probe including a semi-conductor element and characterized by a linear relation between the detected temperature change and the resistance change.
Claim 11
Dependent Claim
49 words
An apparatus as defined in claim 1 wherein there are provided, in association with said means for counting said number of pulses occurring within said predetermined time, means for resetting said counting means to zero coincidentally with the initiation of the counting operation carried on by said counting means.
Claim 12
Dependent Claim
60 words
An apparatus as defined in claim 10 wherein said means for resetting said counting means to zero includes means for feeding a reset pulse to said counter, said reset pulse being of short duration with respect to the duration of any of said pulses being counted, whereby said reset pulse does not mask any of the pulses to be counted.
Claim 13
Dependent Claim
275 words
A portable, battery-voltage supplied clinical thermometer apparatus adapted for repeated measurement and display of the temperature of a patient, said apparatus comprising, in combination, temperature detecting means including a resistor having substantially the same change of resistance for each unit of temperature change, control signal means for generating a control signal having a magnitude which is a function of the resistance of said temperature detecting means and inversely related to supply voltage by a given factor, pulse generating means responsive in frequency to a frequency control signal for generating a purality of discrete electrical pulses, said frequency control signal being a function of both supply voltage and the resistance of said temperature detecting means, means for developing a first signal having a magnitude directly proportional to said supply voltage by said given factor and said pulse frequency, means for comparing said first signal to said control signal and for providing said frequency control signal in response to the relation between said first signal and said control signal, said comparing means being arranged so that a decrease in the magnitude of said first signal causes a corresponding increase in the magnitude of said frequency control signal when that part of the magnitude of the control signal related to the temperature detecting means resistance remains constant, means for counting the number of said pulses occurring within a predetermined time, and means for displaying the number of said pulses counted during said predetermined time period, whereby the number of pulses occurring and being counted during said predetermined time period bears a proportional and substantially linear relation to the resistance of said temperature detecting means notwithstanding supply voltage variations.
Claim 14
Dependent Claim
275 words
A portable, battery-voltage supplied clinical thermometer apparatus adapted for repeated measurement and display of the temperature of a patient, said apparatus comprising, in combination, temperature detecting means including a resistor having substantially the same change of resistance for each unit of temperature change, control signal means for generating a control signal having a magnitude which is a function of the resistance of said temperature detecting means and inversely related to supply voltage by a given factor, pulse generating means responsive in frequency to a frequency control signal for generating a purality of discrete electrical pulses, said frequency control signal being a function of both supply voltage and the resistance of said temperature detecting means, means for developing a first signal having a magnitude directly proportional to said supply voltage by said given factor and said pulse frequency, means for comparing said first signal to said control signal and for providing said frequency control signal in response to the relation between said first signal and said control signal, said comparing means being arranged so that a decrease in the magnitude of said first signal causes a corresponding increase in the magnitude of said frequency control signal when that part of the magnitude of the control signal related to the temperature detecting means resistance remains constant, means for counting the number of said pulses occurring within a predetermined time, and means for displaying the number of said pulses counted during said predetermined time period, whereby the number of pulses occurring and being counted during said predetermined time period bears a proportional and substantially linear relation to the resistance of said temperature detecting means notwithstanding supply voltage variations.
Claim 15
Dependent Claim
52 words
An apparatus as defined in claim 12 which further comprises an integrating circuit coupled to the output of said pulse generating means, and wherein said first signal is formed by said integrating circiut for converting said discrete electrical pulses to a direct current signal for use in developing sid frequency control signal.
Claim 16
Dependent Claim
17 words
An apparatus as defined in claim 12 wherein said pulse generating means is a variable frequency oscillator.
Claim 17
Dependent Claim
52 words
An apparatus as defined in claim 14 wherein said oscillator includes a frequency control comprising a transistor and capacitor forming a part of the oscillator time constant circiut, said transistor being arranged as an impedance, and said impedance being controlled by a feedback relation between the oscillator output and the transistor base.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |