Vital signs monitor

• US 5,355,893 A
• Filed: 09/13/1993
• Issued: 10/18/1994
• Est. Priority Date: 04/06/1992
• Status: Expired due to Fees

• Current Assignee: Donald C. Beck, Peter R. Mick
• Original Assignee: Donald C. Beck, Peter R. Mick
• Inventors: Mick, Peter R., Beck, Donald C.
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): GILBERT, SAMUEL G
• Application Number:
  US08/120,183
• Time in Patent Office: 400 Days
• Field of Search: 128/633, 128/634, 128/637, 128/664, 128/665, 128/670, 128/671, 128/689, 128/691, 128/713, 128/716, 128/718, 128/719, 128/725, 128/736, 128/204.21, 128/724
• US Class Current: 600/532
• CPC Class Codes: A61B 5/083 Measuring rate of metabolism by using breath test, e.g. measuring rate of oxygen consumption
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/091 Measuring volume of inspired or expired gases, e.g. to determine lung capacity
• 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 16/0666 Nasal cannulas or tubing devices for improving normal breathing through the nose A61F5/08; nose filters A62B23/06; outside holding devices A61M25/02
• CPC Class Codes: A61M 2016/0413 with detectors of CO2 in exhaled gases

Abstract

A vital signs monitor comprising a first device capable of being disposed at a selected location on a patient to pass at least exhaled gases therethrough; a second device coupled to the first device to perform a plurality of resistive measurements of certain predetermined parameters of the exhaled gases and a plurality of optical absorption measurements of other predetermined parameters of the exhaled gases; and a third device coupled to the second device responsive to the plurality of resistive measurements and the plurality of optical absorption measurements to provide individual read outs of at least a value of carbon dioxide in the exhaled gases, a value of tidal volume of the exhaled gases and a value of a respiration rate of the patient.

Claims

1. A vital signs monitor comprising:

first means adopted to be disposed at a selected location on a patient to pass at least exhaled gases therethrough;

second means coupled to said first means to perform a plurality of resistive measurements of certain predetermined parameters of said exhaled gases and a plurality of optical absorption measurements of other predetermined parameters of said exhaled gases; and

third means coupled to said second means responsive to said plurality of resistive measurements and said plurality of optical absorption measurements to provide individual read outs of at least a value of carbon dioxide in said exhaled gases, a value of tidal volume of said exhaled gases and a value of a respiration rate of said patient.

2. A monitor according to claim 1, wherein said first means includes

fourth means to measure changes in mass flow of blood associated with systolic and diastolic portions of said patient'"'"'s heart beat,

said fourth means being coupled to said third means to enable said third means to provide a read out of a heart rate of said patient.

3. A monitor according to claim 2, wherein said third means includes

a computer to process said plurality of resistive measurements, said plurality of optical absorption measurements and said changes in mass flow of blood associated with said systolic and said diastolic portions of said patient'"'"'s heart beat in accordance with a predetermined program to provide said read outs.

4. A monitor according to claim 3, wherein said second means includes at least

a housing having a passageway therein to enable a flow of oxygen from an oxygen inlet to said patient and a flow of a combination of said oxygen and said exhaled gases from said patient and a venturi tube coupled to said passageway to predeterminedly control said flow of said combination of said oxygen and said exhaled gases in said passageway,

a first temperature sensitive resistance means disposed in said passageway adjacent said inlet to measure a temperature of said oxygen at said inlet,

a second temperature sensitive resistance means disposed in said passageway responsive to said combination of said oxygen and said exhaled gases to measure a temperature of said combination of said oxygen and said exhaled gases, and

a third temperature sensitive resistance means disposed in said venturi tube to measure at least a flow rate of said combination of said oxygen and said exhaled gases in said housing,

said first, second and third temperature sensitive resistance means performing said plurality of resistive measurements.

5. A monitor according to claim 4, wherein said second means further includes

a first optical absorption detection means disposed in an operative relationship with said flow of said combination of said oxygen and said exhaled gases to measure a value of humidity present therein, and

a second optical absorption detection means disposed in an operative relationship with said flow of said combination of said oxygen and said exhaled gases to measure a value of carbon dioxide present therein,

said first and second optical absorption detection means performing said plurality of optical absorption measurements.

6. A monitor according to claim 5, wherein said second means further includes

an electronic circuit means coupled to said third resistance means to raise a resistance value and, hence, a temperature value thereof above a temperature of said flow of said combination of said oxygen and said exhaled gases so that said resistance value is lowered in proportion to a cooling effect of said flow of said combination of said oxygen and said exhaled gases to enable detection of said flow rate.

7. A monitor according to claim 6, wherein said third means further includes

fifth means for providing first alarms when predetermined threshold levels of said plurality of resistive measurements, said plurality of optical absorption measurements and said changes in mass flow of blood associated with said systolic and said diastolic portions of said patient'"'"'s heart beat are exceeded and a second alarm when said predetermined threshold levels are not exceeded but a combination of said plurality of resistive measurements, said plurality of optical absorption measurements and changes in mass flow of blood associated with said systolic and said diastolic portions of said patient'"'"'s heart beat exceed other predetermined criteria.

8. A monitor according to claim 3, wherein said second means includes at least

a housing having a passageway therein to enable a flow of oxygen from an oxygen inlet to said patient and a flow of a combination of said oxygen and said exhaled gases from said patient,

a first optical absorption detection means disposed in an operative relationship with said flow of said combination of said oxygen and said exhaled gases to measure a value of humidity present therein, and

a second optical absorption detection means disposed in an operative relationship with said flow of said combination of said oxygen and said exhaled gases to measure a value of carbon dioxide present therein,

said first and second optical absorption detection means performing said plurality of optical absorption measurements.

9. A monitor according to claim 8, wherein said third means further includes

fifth means for providing first alarms when predetermined threshold levels of said plurality of resistive measurements, said plurality of optical absorption measurements and said changes in mass flow of blood associated with said systolic and said diastolic portions of said patient'"'"'s heart beat are exceeded and a second alarm when said predetermined threshold levels are not exceeded but a combination of said plurality of resistive measurements, said plurality of optical absorption measurements and said changes in mass flow of blood associated with said systolic and said diastolic portions of said patient'"'"'s heart beat exceed other predetermined criteria.

10. A monitor according to claim 1, wherein said first means includes

a selected one of a face mask, an endotracheal tube and a nasal-oral ventilation adaptor.

11. A monitor according to claim 10, wherein said nasal-oral ventilation adapter includes

an optical arrangement coupled to said third means and disposed in at least one nasal portion of said nasal-oral adapter, said optical arrangement including fourth means to transmit light through blood perfused tissue of a nasal passage containing said one nasal portion and fifth means to detect changes in said light transmitted through said blood perfused tissue to thereby detect a change in mass flow of blood associated with systolic and diastolic portions of said patient'"'"'s heart rate which is displayed as a read out on said third means.

12. A monitor according to claim 11, wherein said third means includes

a computer having sixth means to process said plurality of resistive measurement, said plurality of optical absorption measurements and said change in mass flow of blood associated with said portions of said patient'"'"'s heart beat in accordance with a predetermined program to provide said read outs.

13. A monitor according to claim 12, wherein said computer further includes seventh

means to provide first alarms when predetermined threshold levels of said plurality of resistive measurements, said plurality of optical absorption measurements and said change in mass flow of blood associated with said portions of said patient'"'"'s heart beat are exceeded and a second alarm when said predetermined threshold levels are not exceeded but a combination of said plurality of resistive measurements, said plurality of optical absorption measurements and said change in mass flow of blood associated with said portions of said patient'"'"'s heart beat exceed other predetermined criteria.

14. A monitor according to claim 10, further including

a source of a selected one of dry air, moist air, oxygen and oxygen plus nitrogen;

said selected one of a face mask, an endotracheal tube and a nasal-oral ventilation adapter coupled to said source to enable administration of said selected one of dry air, moist air, oxygen and oxygen plus nitrogen to said patient;

said second means measuring a value of an unbreathed portion of said selected one of dry air, moist air, oxygen and oxygen plus nitrogen in said exhaled gases; and

said third means providing a read out of said value of said unbreathed portion of said selected one of dry air, moist air, oxygen and oxygen plus nitrogen in said exhaled gases.

15. A monitor according to claim 1, wherein said second means includes at least

a housing having a passageway therein to enable a flow of oxygen from an oxygen inlet to said patient and a flow of a combination of said oxygen and said exhaled gases from said patient and a venturi tube coupled to said passageway to predeterminedly control said flow of said combination of said oxygen and said exhaled gases in said passageway,

a first temperature sensitive resistance means disposed in said passageway adjacent said inlet to measure a temperature of said oxygen at said inlet,

a second temperature sensitive resistance means disposed in said passageway responsive to said combination of said oxygen and said exhaled gases to measure a temperature of said combination of said oxygen and said exhaled gases, and

a third temperature sensitive resistance means disposed in said venturi tube to measure at least a flow rate of said combination of said oxygen and said exhaled gases in said housing,

said first, second and third temperature sensitive resistance means performing said plurality of resistance measurements.

16. A monitor according to claim 15, wherein said second means further includes

a first optical absorption detection means disposed in an operative relationship with said flow of said combination of said oxygen and said exhaled gases to measure a value of humidity present therein, and

a second optical absorption detection means disposed in an operative relationship with said flow of said combination of said oxygen and said exhaled gases to measure a value of carbon dioxide present therein,

said first and second optical absorption detection means performing said plurality of optical absorption measurements.

17. A monitor according to claim 16, wherein said second means further includes

an electronic circuit means coupled to said third resistance means to raise a resistance value and, hence, a temperature value thereof above a temperature of said flow of said combination of said oxygen and said exhaled gases so that said resistance value is lowered in proportion to a cooling effect of said flow of said combination of said oxygen and said exhaled gases to enable detection of said flow rate.

18. A monitor according to claim 17, wherein said third means further includes

fourth means for providing first alarms when predetermined threshold levels of said plurality of resistive measurements and said plurality of optical absorption measurements are exceeded and a second alarm when said predetermined threshold levels are not exceeded but a combination of said plurality of resistive measurements and said plurality of said optical absorption measurements exceed other predetermined criteria.

19. A monitor according to claim 1, wherein said second means includes at least

a housing having a passageway therein to enable a flow of oxygen from an oxygen inlet to said patient and a flow of a combination of said oxygen and said exhaled gases from said patient,

a first optical absorption detection means disposed in an operative relationship with said flow of said combination of said oxygen and said exhaled gases to measure a value of humidity present therein, and

a second optical absorption detection means disposed in an operative relationship with said flow of said combination of said oxygen and said exhaled gases to measure a value of carbon dioxide present therein,

said first and second optical absorption detection means performing said plurality of optical absorption measurements.

20. A monitor according to claim 1, wherein said third means further includes

fourth means for providing first alarms when predetermined threshold levels of said plurality of resistive measurements and said plurality of optical absorption measurements are exceeded and a second alarm when said predetermined threshold levels are not exceeded but a combination of said plurality of resistive measurements and said plurality of optical absorption measurements exceed other predetermined criteria.

21. A monitor according to claim 1, wherein said third means further includes

fourth means responsive to given ones of said value of carbon dioxide, said value of tidal volume and said value of respiration rate to calculate at least cardiac output of said patient.

22. A monitor according to claim 1, wherein said third means further includes

fourth means for enabling playing back historical values of at least said carbon dioxide, said tidal volume, said respiration rate and other predetermined data obtained previously from said patient.

23. A monitor according to claim 1, further including predetermined critical care monitor means, coupled to said third means, for delivering data to said third means, said critical care monitor means including selected ones of tymphanic monitors, infra red thermometers, oximeters, sphignomanometers, electro cardiographs, cardiac output monitors, and left ventricular injection volume monitors.