Electronic thermometer with probe isolation chamber

[54] ELECTRONIC THERMOMETER WITH PROBE ISOLATION CHAMBER

[75] Inventors: Laurie J. Burger, North Branford;

Joel N. Heifer, Cheshire; Donald E.
Protzmann, Litchfield; Robert F.
Uhl, Cheshire, all of Conn.

[73] Assignee: Chesebrough-Pond's, Inc.,
Greenwich, Conn.

[21] Appl. No.: 681,308

[22] Filed: Dec. 13,1984

[51] Int. CI." A61B 5/00

[52] U.S. CI 128/736; 374/170;

200/153 T

[58] Field of Search 128/736; 374/169, 170;

324/79 D; 200/153 T, 302.1, 61.58, 52 R, 81 H

[56] References Cited

U.S. PATENT DOCUMENTS

2,824,183 2/1958 Marasco et al 200/302.1

3,785,207 1/1974 Brzezinski 374/169

3,822,598 7/1974 Brothers et al 374/169

3,834,238 9/1974 Mueller et al 374/170

3,895,198 7/1975 Piber 200/153 T

3,903,744 9/1975 Cone 374/170

4,007,832 2/1977 Paull et al 374/170

4,121,574 10/1978 Lester 128/736

4,455,096 6/1984 Brandstedt 374/170

4,487,208 12/1984 Kamers 374/170

Primary Examiner—Edward M. Coven
Assistant Examiner—Max F. Hindenburg
Attorney, Agent, or Firm—Brumbaugh, Graves,
Donohue & Raymond

[57] ABSTRACT

An electronic thermometer includes a color coded probe permanently fastened by an electrical cable to a color coded isolation chamber to prevent inadvertent use of a rectal probe with an oral isolation chamber. Red and blue isolation chambers used for oral and rectal temperatures, respectively, can readily be used with one thermometer housing. A connector between the isolation chamber and the housing automatically connects and disconnects the probe and the thermometer circuits when the isolation chamber is inserted into or removed from the housing. Moreover, insertion of the probe into the isolation chamber automatically actuates a switch in the electronic thermometer housing to deactivate the electric circuits. Withdrawal of the probe from the chamber automatically supplies power to the thermometer circuits to ready the thermometer for operation.

6 Claims, 4 Drawing Figures

ELECTRONIC THERMOMETER WITH PROBE ISOLATION CHAMBER

BACKGROUND OF THE INVENTION

In recent years electronic thermometers, which provide rapid and accurate readings of body temperature, have supplanted mercury thermometers in hospitals and the like. Such electronic thermometers ordinarily use a probe at the end of which is located a temperature-sensitive element, for example a thermistor. After a sterile disposable plastic cover is placed on the probe, it may be inserted into a body orifice.

In presently used instruments, the probe is detachably coupled to an isolation chamber by a cable and connector. With this arrangement, an operator can readily disconnect a probe from one chamber and connect it to another isolation chamber, thereby increasing the possibility that a rectal probe may be inserted into an oral isolation chamber, or vice versa, an undesired procedure. Because it is necessary to use two different electronic thermometers for taking oral and rectal temperatures, the inappropriate practice of switching probes and using an oral probe with a rectal isolation chamber was inadvertently encouraged.

Moreover, some prior thermometers used an external switch on the isolation chamber or housing, a distraction and a disadvantageous arrangement since the units often are left energized resulting in unnecessary battery use.

SUMMARY OF THE INVENTION

The present invention provides an electronic thermometer usable with oral and rectal probes permanently attached to oral and rectal isolation chambers, thus precluding inadvertent use of a probe with the wrong isolation chamber, an unsanitary procedure.

More particularly, in the inventive electronic thermometer, a color coded probe is permanently fastened by an electrical cable to a color coded isolation chamber. Red and blue isolation chambers are used for oral and rectal temperatures, respectively, universal hospital color codes. If it becomes necessary to take an oral temperature and the nurse finds the only convenient electronic thermometer has a blue isolation chamber and probe, and there is not another entire unit available, it is only necessary to substitute a red isolation chamber and attached probe. A connector between the isolation chamber and the housing automatically connects and disconnects the probe and the thermometer circuits when the isolation chamber is inserted into or removed from the housing.

Another feature of the invention includes the elimination of an external switch. More particularly, insertion of the probe into the isolation chamber actuates a switch in the electronic thermometer housing to deactivate the circuits. Upon withdrawal of the probe from the isolation chamber, the switch is closed automatically to supply power to the circuits and ready the thermometer for operation.

These and further features and advantages of the invention will be more readily understood when the following description is read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view in perspective of the inventive electronic thermometer with a probe out of an isolation 5 chamber;

FIG. 2 is a perspective of the isolation chamber removed from the thermometer housing with the probe in the chamber;

FIG. 3 is a cross-section of the isolation chamber with 10 the probe in stored position showing a switch actuating device operated by insertion of the probe into the chamber; and

FIG. 4 is a view of the housing of the electronic thermometer, partially broken away, showing a switch 15 operated by insertion of the probe into the isolation chamber, and the electrical connection of the probe to the thermometer circuits in the housing.

DESCRIPTION OF EXEMPLARY 20 EMBODIMENTS

Referring to the drawings with particular reference to FIG. 1, a housing 10 containing the electrical components of the electronic thermometer is provided at its upper end with a display panel 11 to read out body

25 temperature. A color coded isolation chamber 12 (FIG. 2) fits into a compartment 10a (FIG. 4) at one side of the housing 10. A coiled cable 18, also color coded, extends from a reinforcing bushing 18a fastened in the isolation chamber 12 to a color coded probe 19 and

30 connects via conductors 20 to receptacle contacts 21 (FIG. 3).

When the probe 19 is withdrawn from the isolation chamber 12, its tip is inserted into an elongated cover 19a held in a box located in the housing 10. For hygienic 35 purposes, the probe 19 with the cover 19a is of too great a diameter to be inserted fully into the isolation chamber 12.

The isolation chamber 12 is shown in FIGS. 2 and 4 with the probe 19 fully inserted and in its normal inoper

40 ative position. The connector receptacles 21 are adapted to receive pins 22 (FIG. 4) to connect the probe 19 electrically to conductors 23 leading to circuits in the electronic thermometer. More particularly, a temperature sensitive element, for example a thermistor, in the

45 tip of the probe 19, is connected electrically to conductors 23 by the cable 18 and the receptacles 21 and pins 22.

A switch 24 in the housing 10, for example a microswitch as shown in FIG. 4, includes an operating arm

50 25. When in its operated position, as shown in solid line in FIG. 4, the switch interrupts the circuits in the electronic thermometer to render it inoperative. When the arm 25 is in its broken line position, the switch 24 is closed to energize the electronic thermometer.

55 Included in the isolation chamber 12 is a tube 13, forming an elongated chamber for the probe 19. A cylindrical opening 14 provided in the tube 13 is formed with an annular shoulder 14a at its inner edge. A ball 15 is retained in the opening 14 by an elastic sleeve 16

60 stretched around a reduced diameter section 17 of the tube 13. Note that both the external and internal diameters of the section 17 are reduced. External shoulders 17a hold the sleeve in place and internal tapered shoulders 176 guide the tip of the probe 19 through the sec

65 tion 17. With the probe 19 fitting closely within the cylindrical opening in the section 17, insertion of the probe forces the ball 15 outwardly against the elastic sleeve, as shown in FIG. 3.