Endotracheal tube/stethoscope/thermistor combination

United States Patent m

Bell et al.

[54] ENDOTRACHEAL

TUBE/STETHOSCOPE/THERMISTOR
COMBINATION

[75] Inventors: Floyd R. Bell, Portsmouth, Ohio;

Thomas H. McKay, Versailles, Ky.

[73] Assignee: Medi-Tube Corporation, Lexington, Ky.

[21] Appl. No.: 811,531
[22] Filed: Dec. 20, 1991

[51] Int. C1.5 A61B 5/02

[52] U.S. Q 128/715; 128/736

[58] Field of Search 128/715, 773, 736

[56] References Cited

U.S. PATENT DOCUMENTS

Re. 31,377 9/1983 Mylrea et al 128/642

3,734,094 5/1973 Calinog 128/642

4,263,921 4/1981 Trugillo 128/736

4,304,239 12/1981 Perlin 128/642

4,383,534 5/1983 Peters 128/671

4,917,107 4/1990 Bell et al 128/715

4,967,759 11/1990 Teves 128/715

5,029,591 7/1991 Teves 128/715

Primary Examiner—William E. Kamm Assistant Examiner— Scott M. Getzow Attorney, Agent, or Firm—King and Schickli

IIIIIIIUIIIIIIIIIIIIII

US005295489A

[ii] Patent Number: 5,295,489 [45] Date of Patent: Mar. 22,1994

[57] ABSTRACT

An endotracheal tube, stethoscope, and thermistor combination is provided to allow simultaneous patient ventilation, vital sounds monitoring, and body core temperature monitoring by a single instrument. The tube includes an inflation cuff adjacent the distal end and a longitudinal pressure conduit to inflate the cuff to seal against the trachea wall. An audio cuff extends at least partially coextensive and concentrically with the inflation cuff and has sufficient resiliency to vibrate in response to the patient's vital sounds. Audio ports face toward the left side, and thus the heart of the patient to receive heart sounds most directly. A thermistor extends longitudinally along the posterior wall of the preferably bowed tube for contact of the transducer with the patient's mucous membrane for accurately monitoring of the body core temperature. The inflation cuff comprises a highly flexible bulb in direct contact with the trachea wall and the audio cuff is a sleeve inside the bulb and spaced peripherally from the tube to allow vibration. The sleeve has integral ribs so as to be sufficiently stable to maintain the desired spacing and thus assure maximum sound pick-up. A pressure conduit and audio conduit extend along the side wall and open into the inflation and audio cuffs, respectively.

15 Claims, 2 Drawing Sheets

ENDOTRACHEAL
TUBE/STETHOSCOPE/THERMISTOR
COMBINATION

5

BACKGROUND OF THE INVENTION

The present invention relates to the construction of an endotracheal tube for applying anesthetic gases and/ot supplying oxygen to a patient, and more particularly to an endotracheal tube combined with an integral 10 stethoscope and thermistor to allow more efficient monitoring of the patient's vital sounds and body core temperature during an operation.

BACKGROUND ART 15

During surgical operations, a preferred method of ventilating a patient, including applying an anesthetic to the patient, involves the use of a tube extending into the trachea of the patient. The tube is inserted through the throat of the patient to a location in the trachea just 20 below the vocal cords. At this location, an inflation cuff is pressurized in order to seal against the walls of the trachea. When this sealing is accomplished, the desired intrapulmonary pressure can be established by the introduction of the appropriate gases. These gases are admin- 25 istered through a ventilator machine attached to the proximal end of the tube.

In prior U.S. Pat. Nos. 4,607,643 and 4,917,107, an endotracheal tube/stethoscope combination is disclosed to allow simultaneous patient ventilation and monitor- 30 ing of vital sounds by a single instrument so as to minimize the number of invasive instruments in the body during an operation. The endotracheal tube, disclosed therein, includes a cuff adjacent the distal end and at least one longitudinal conduit to inflate the cuff to seal 35 and/or pick up sounds. A preferred embodiment includes an audio cuff extending at least partially coextensive and concentrically with a separate inflation cuff and is designed to vibrate in response to the patient's vital sounds. The inflation cuff comprises a highly flexi- 40 ble bulb in direct contact with the trachea wall and the audio cuff is a sleeve inside the bulb and spaced peripherally from the tube to allow sound-induced vibration. The sleeve may be foam-filled to maintain the even spacing with respect to the tube upon inflation of the 45 bulb. The pressure conduit of the preferred embodiment extends longitudinally along the tube and opens into communication with the inflation cuff. An audio conduit extends along the side wall and opens through a plurality of ports forming an audio manifold into the 50 audio cuff.

The endotracheal tube/stethoscope combination of the aforementioned patents, however, suffers from several disadvantages. Chief among these disadvantages is the inability to accurately and consistently position the 55 audio ports, contained within the audio cuff, to receive the patient's vital sounds. In this regard, it has been discovered that to be most efficient the ports should face toward the left side of the patient toward the heart. This is shown to improve the reception of the heart 60 sounds by providing for a more direct, unobstructed path for the sound to travel. An additional disadvantage is the susceptibility of an audio cuff, positioned within an inflation cuff, to partially collapse upon pressurization of the inflation cuff so that its reception of the 65 patient's vital sounds is impaired. While the aforementioned patents suggest filling the sleeve with foam to maintain its spacing, such foam-filling may increase the

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expense of manufacturing. Under some conditions, the foam may actually damp the transmission of the patient's vital sounds.

Furthermore, with the endotracheal tube/stethoscope combination, the anesthetist must not only operate and monitor the endotracheal tube/stethoscope combination, but also monitor a separate thermometer to determine the patient's body core temperature during the operation. In addition to monitoring the two separate instruments, the anesthetist must ensure that they are maintained in their proper location. With multiple instruments, there is a greater likelihood of the thermometer or other vital instrument being disturbed by the others, such as the doctor performing the operation, or the unexpected movement of the patient's body.

DISCLOSURE OF THE INVENTION

Thus, with the above needs for improvement in focus, it is a primary object of the present invention to provide a simplified, combined endotracheal tube, stethoscope, and temperature transducer to allow more efficient introduction of anesthetics or the like to a patient and simultaneous monitoring of the vital sounds and the core body temperature of the patient.

It is another object of the present invention to provide an endotracheal tube/stethoscope/thermistor combination providing greatly increased ease of handling and use by the anesthetist.

It is still another object of the present invention to provide an instrument for administering anesthetics and simultaneously monitoring vital sounds and core body temperature that is immediately ready to use after intubation and easier to properly insert and to maintain in the proper position throughout the operation, and to allow for a more direct path for the transmission of the patient's vital sounds.

It is another object of the present invention to provide a combined tracheal tube, stethoscope, and thermistor that can be inexpensively manufactured and reduce the overall expense involved in instruments and related apparatus needed by an anesthetist.

It is still another object of the present invention to provide an endotracheal tube with an inflation cuff for sealing the trachea, a reinforced audio cuff forming a stethoscope transducer within the inflation cuff, and a thermistor forming a temperature transducer positioned along the posterior face of the tube.

Additional objects, advantages and other novel features of the invention will be set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned with the practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

To achieve the foregoing and other objects, and in accordance with the purposes of the present invention as described herein, an improved assembly for use by an anesthetist during an operation for providing endotracheal ventilation, monitoring vital sounds by stethoscope, and monitoring core body temperature by thermistor is provided. The assembly includes a trachea tube, an inflation cuff located at the distal end surrounding the tube, means for pressurizing the cuff to seal against the trachea wall, an audio cuff having sufficient resiliency to vibrate to monitor patient vital sounds, and a