Endotracheal tube and mass spectrometer

• US 4,966,141 A
• Filed: 06/12/1989
• Issued: 10/30/1990
• Est. Priority Date: 06/13/1988
• Status: Expired due to Term

• Current Assignee: John H. Broadhurst, Marvin B. Bacaner
• Original Assignee: John H. Broadhurst, Marvin B. Bacaner
• Inventors: Bacaner, Marvin B., Broadhurst, John H.
• Primary Examiner(s): Burr, Edgar S.
• Assistant Examiner(s): Lewis, Aaron J.
• Application Number:
  US07/364,109
• Time in Patent Office: 505 Days
• Field of Search: 128/716, 128/719, 128/632, 128/635, 128/207.14, 128/207.15, 128/206.29, 604/45
• US Class Current: 128/207.14
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/029 Measuring or recording blood output from the heart, e.g. minute volume A61B8/065 takes precedence
• CPC Class Codes: A61M 16/0459 one cuff behind another
• CPC Class Codes: A61M 16/0493 with means for protecting the tube from damage caused by the patient's teeth, e.g. bite block
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/0413 with detectors of CO2 in exhaled gases
• CPC Class Codes: A61M 2230/432 partial CO2 pressure (P-CO2)
• CPC Class Codes: A61M 2230/435 partial O2 pressure (P-O2)

Abstract

A non-invasive apparatus for continuously measuring the cardiac output and cardio-respiratory function includes a gas sampling device which is inserted into the mouth of a human subject. The gas sampling device may be a disposable endotracheal tube or a smaller disposable mouthpiece or facial mask. Each of these gas sampling devices is provided with a plurality of passages for sampling the lung gases and for continuously sampling the gas pressure on opposite sides of a capillary restriction member. A miniature motor pump mass spectrometer module is mounted on the upper end of the endotracheal tube or mouthpiece. Electronic circuitry connected to the mass spectrometer permits constant visual monitoring of the cardiac output and cardio-respiratory function.

Claims

1. A disposable tissue gas sampling mouthpiece device for use in obtaining tissue and respiratory gases for analysis from a human subject, comprising:

an elongate flexible tube for insertion into the mouth of a human subject, including a cylindrical tubular wall defining a central passage therethrough and having upper and lower ends, said lower end positioned with the oral cavity of a human subject and said upper end extending exteriorly of a human subject adapted to be connected to a miniature motor pump and mass spectrometer module, the motor pump and mass spectrometer module being connected to a vacuum source,

an elongate axially extending tissue gas sample passage and an elongate axially extending tissue gas return passage in the wall of said tube, each passage having an upper and lower end, the upper end of each passage adapted to be connected in communicating relation with the motor pump and mass spectrometer module, the lower end of said tissue gas return passage communicating with said central passage, and

a hollow tissue sampling member secured to said tube and extending outwardly therefrom and adapted to be positioned between the teeth and lips of a human subject, said tissue sampling member having one surface thereof disposed in conforming relation to mouth and lip tissue of a human subject, the lower end of said tissue sampling passage communicating with the interior of said hollow tissue sampling member, said one surface of the tissue sampling member having openings therein communicating with the interior thereof, whereby, when said tissue gas sample passage is subjected to a vacuum by the vacuum source connected to the miniature motor pump and mass spectrometer module, the lip and mouth tissues of a human subject will be drawn into intimate contact with said one surface of said gas sampling member to cause outgassing of tissue gases from the mouth and lip tissues through the openings in said gas sampling member through the tissue gas sample passage and into a pump motor and mass spectrometer module for analysis of the tissue gases.

2. The mouthpiece device as defined in claim 1 and a capillary restriction member positioned within said tube and having a plurality of axially extending capillary passages therein for restricting the axial flow of lung gases through the central passage thereof, and

first and second axially extending pressure sensing passages in the wall of said tube and each having an upper end and a lower end, a first pressure sensing opening in said tube intercommunicating the central passage with one of said pressure sensing passages, a second pressure sensing opening intercommunicating the central passage of said tube with said other pressure sensing passage, one of said pressure sensing openings being located downstream of said capillary restricting member, and the other of said pressure sensing openings being located upstream of said capillary restriction member whereby, when said pressure sensitive passages are connected in communicating relation to a differential pressure transducer, the respiratory flow rate of a human subject can be determined.

3. The mouthpiece device as defined in claim 1 and an elongate axially extending lung gas sample passage and an elongate axially extending lung gas return passage in the wall of said tube, each of said lung gas passages having an upper end and a lower end, a first lung gas sample opening in the tube interconnecting the lower end of said lung gas sample passage with said central passage, a second lung gas sample opening in said tube interconnecting the lower end of said lung gas return passage with said central passage, the respective upper ends of said lung gas passages being adapted to be connected to the motor pump and mass spectrometer module whereby the lung gases from a human subject may be circulated through the mass spectrometer and analyzed.

4. The mouthpiece device as defined in claim 1 wherein said one surface of the tissue sampling member comprises the front surface.

5. The mouthpiece device as defined in claim 1 and an exterior face-engaging element secured to said tube and extending outwardly therefrom and having a concave rear surface engaging the face of a human subject.

6. The mouthpiece device as defined in claim 1 and an exterior element secured to said tube defining a mask for engaging the face of a human subject.

7. The mouthpiece device as defined in claim 1 and means for sensing the respiratory flow rate of a human subject through said central passage.

8. The mouthpiece device as defined in claim 7 wherein said means comprises a thermistor flow meter.

9. The mouthpiece device as defined in claim 7 wherein said means comprises a respiratory spirometer.

10. A disposable tissue gas sampling mouthpiece device for use in obtaining tissue and respiratory gases for analysis from a human subject, comprising:

a mouthpiece device including an elongate flexible tube for insertion into the mouth of a human subject, including a cylindrical tubular wall defining a central passage therethrough and having upper and lower ends, said lower end positioned within the oral cavity of a human subject and said upper end extending exteriorly of a human subject,

a miniature motor pump and mass spectrometer module, means connecting the motor pump mass spectrometer module to a vacuum source, means connecting the motor pump mass spectrometer module with the upper end of said flexible tube to intercommunicate the central passage thereof with the motor pump mass spectrometer module,

an elongate axially extending tissue gas sample passage and an elongate axially extending tissue gas return passage in the wall of said elongate flexible tube, each passage having an upper and lower end, the upper end of each passage communicating with said motor pump and mass spectrometer module, the lower end of said tissue gas return passage communicating with said central passage, and

a hollow tissue sampling member secured to said tube and extending outwardly therefrom and adapted to be positioned between the teeth and lips of a human subject, said tissue sampling member having one surface thereof disposed in conforming relation to mouth and lip tissue of a human subject, the lower end of said tissue sampling passage communicating with the interior of said hollow tissue sampling member, said one surface of the tissue sampling member having openings therein communicating with the interior thereof, whereby, when said tissue gas sample passage is subjected to a vacuum by the vacuum source connected to the miniature motor pump and mass spectrometer module, the lip and mouth tissues of a human subject will be drawn into intimate contact with said one surface of said gas sampling member to cause outgassing of tissue gases from the mouth and lip tissues through the openings in said gas sampling member through the tissue gas sample passage and into the pump motor and mass spectrometer module for analysis of the tissue gases.