DEVICE AND METHOD FOR DETECTING HEART BEATS USING AIRWAY PRESSURE

• US 20100036266A1
• Filed: 07/31/2009
• Published: 02/11/2010
• Est. Priority Date: 07/31/2008
• Status: Abandoned Application

• Current Assignee: Laerdal Medical AS (Laerdal Medical Corporation)
• Original Assignee: Laerdal Medical AS (Laerdal Medical Corporation)
• Inventors: Nysaether, Jon, Eilevstjonn, Joar, Myklebust, Helge
• Application Number:
  US12/533,784
• Publication Number:
  US 20100036266A1
• Time in Patent Office: Days
• US Class Current: 600/500
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 5/02444 Details of sensor A61B5/02427 takes precedence
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/412 Detecting or monitoring sepsis
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives
• CPC Class Codes: A61H 2201/5071 Pressure sensors
• CPC Class Codes: A61H 2230/06 Heartbeat rate
• CPC Class Codes: A61H 31/00 Artificial respiration or heart stimulation, e.g. heart massage artificial respiration by treatment with gas or air, e.g. mouth-to-mouth respiration A61M16/00; applying electric currents by contact electrodes for stimulation, e.g. heart pace-makers A61N1/36 ; teaching or training models, demonstration models for medical purposes G09B23/288
• CPC Class Codes: A61M 16/0078 Breathing bags
• CPC Class Codes: A61M 16/0084 self-reinflatable by elasticity, e.g. resuscitation squeeze bags
• CPC Class Codes: A61M 16/0858 Pressure sampling ports
• CPC Class Codes: A61M 16/0866 Passive resistors therefor
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2205/581 by audible feedback
• CPC Class Codes: A61M 2205/583 by visual feedback

Abstract

Embodiments are directed to a device and method for detecting heart beats and/or monitoring ventilation and/or respiration of a patient using air pressure. In one embodiment, a monitoring device comprises a gas duct and at least one pressure sensor configured to measure pressure in the duct. The duct may be in fluid communication with a patients airways. Based on the sensed pressure, a heart beat of the patient may be detected. In another embodiment, a flow rate of the air expired from the patient may be calculated based on the pressure and a known flow resistance.

Claims

1. A device for obtaining heart beat information of a patient, comprising:

a duct configured to allow a gas to pass therethrough;

at least one pressure sensor connected to the duct and configured to measure the pressure in the duct; and

a processing unit connected to the pressure sensor and operable to generate heart beat information from the pressure signal.

2. The device according to claim 1, wherein the duct is connected to a respiration device.

3. The device according to claim 1, wherein the duct is integrated in a respiration device.

4. The device according to claim 1, further comprising a restriction arranged in the duct, and wherein the pressure sensor is configured to measure a pressure drop across the restriction as a pressure difference between a location in the duct at a first side of the restriction and a known, substantially constant pressure, arranged at a second side of the restriction.

5. The device according to claim 1 further comprising a one-way valve with known flow resistance connected to the duct.

6. The device according to claim 2 wherein the respiration device comprises a respiratory mask or a tracheal tube.

7. The device according to claim 3, wherein the respiration device comprises a bellow.

8. The device according to claim 4, wherein the pressure drop is measured by a single pressure sensor.

9. The device according claim 1, further comprising a restriction arranged in the duct and wherein the pressure sensor is arranged to measure pressure at a location at a first side of the restriction.

10. The device according to claim 1, further comprising a restriction having a first and second side arranged in the duct and wherein the restriction is shaped to ensure that a flow velocity is substantially equal on the first and second sides of the restriction.

11. The device according to claim 1, wherein the pressure sensor is an absolute pressure sensor.

12. The device according to claim 1, wherein the pressure sensor is a differential pressure sensor.

13. The device according to claim 4, wherein the known, substantially constant pressure, is ambient pressure.

14. The device according to claim 1, wherein the processing unit is adapted to calculate flow values from a linear relationship between pressure drop and flow.

15. The device according to claim 1, wherein the processing unit is adapted to calculate respired volume.

16. A method for obtaining heart beat information of a patient, comprising:

measuring pressure in a gas duct connected to a patient'"'"'s airways; and

deriving patient heart beat information based on the measured pressure.

17. The method according to claim 16, further comprising providing an elevated pressure in the lungs of the patient.

18. The method according to claim 16, further comprising connecting the duct to a respiration device.

19. The method according to claim 16, wherein the step of measuring pressure in a gas duct comprises measuring a pressure drop across a restriction as the difference between a pressure measured at a location in the duct at a first side of the restriction and a known, substantially constant pressure, arranged at a second side of the restriction.

20. The method according to claim 19, wherein measuring the pressure drop is by a single pressure sensor.

21. The method according to claim 19, wherein the pressure sensor is arranged at the first side of the restriction.

22. The method according to claim 19, wherein the flow velocity is substantially equal on both sides of the restriction.

23. The method according to claim 17, further comprising calculating flow values from a linear relationship between pressure drop and flow.