Gas sampling system

• US 20040060443A1
• Filed: 09/27/2002
• Published: 04/01/2004
• Est. Priority Date: 09/27/2002
• Status: Active Grant

• Current Assignee: Welch Allyn Protocol Incorporated (Welch Allyn Incorporated)
• Original Assignee: Welch Allyn Protocol Incorporated (Welch Allyn Incorporated)
• Inventors: Richardson, Peter
• Granted Patent: US 6,783,573 B2
• Time in Patent Office: Days
• US Class Current: 96/108
• CPC Class Codes: A61B 5/097 Devices for facilitating collection of breath or for directing breath into or through measuring devices
• 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 16/0808 Condensation traps
• CPC Class Codes: A61M 16/0816 Joints or connectors
• CPC Class Codes: A61M 16/085 Gas sampling
• CPC Class Codes: A61M 2202/0208 Oxygen
• CPC Class Codes: A61M 2205/7536 allowing gas passage, but preventing liquid passage, e.g. liquophobic, hydrophobic, water-repellent membranes
• CPC Class Codes: A61M 2230/432 partial CO2 pressure (P-CO2)
• CPC Class Codes: B01D 53/02 by adsorption, e.g. preparative gas chromatography solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01
• CPC Class Codes: Y10S 55/35 Respirators and register filters

Abstract

The present invention is directed to a gas sampling system for conducting respiratory gases from a patient respiratory gas output mechanism to a respiratory gas monitoring device. The respiratory gas monitoring device is equipped with a monitor input connector. The gas sampling system includes an input connector configured to couple the gas sampling system to the patient respiratory gas output mechanism. A gas sampling tube is coupled to the input connector. The gas sampling tube is configured to conduct the respiratory gases from the patient to the gas monitoring device. An output connector couples the gas sampling tube to the monitor input connector. An output dryer tube is coupled between the gas sampling tube and the output connector. The output dryer tube is characterized by a tube length and a relative moisture removal efficiency. The relative moisture removal efficiency is dependent on the tube length. The tube length is selected to limit the moisture content of the respiratory gasses being directed into the respiratory gas monitor to a predetermined level.

Claims

1. A gas sampling system for conducting respiratory gases from a patient respiratory gas output mechanism to a respiratory gas monitor, the gas sampling system comprising:

an input connector configured to couple the gas sampling system to the patient respiratory gas output mechanism;

a gas sampling tube coupled to the input connector, the gas sampling tube being configured to conduct the respiratory gases from the patient to the gas monitoring device;

an output connector coupling the gas sampling tube to the respiratory gas monitor; and

an output dryer tube coupled between the gas sampling tube and the output connector, the output dryer tube being characterized by a tube length and a relative moisture removal efficiency, the relative moisture removal efficiency being dependent on the tube length, the tube length being selected to limit the moisture content of the respiratory gasses being directed into the respiratory gas monitor to a substantially predetermined level.

2. The system of claim 1, further comprising an input dryer tube coupled between the input connector and the gas sampling tube, the input dryer tube being characterized by a tube length and a relative moisture removal efficiency, the relative moisture removal efficiency being dependent on the tube length.

3. The system of claim 1, wherein the output connector includes a valve mechanism that closes in response to exposure to a predetermined amount of moisture.

4. The system of claim 3, wherein the tube length is selected to ensure that the valve mechanism is exposed to an amount of moisture below the predetermined amount.

5. The system of claim 3, wherein an effective operational life-span of the gas sampling system ends upon closure of the valve mechanism.

6. The system of claim 5, wherein the tube length is selected to extend the effective operational life-span of the gas sampling system to at least 100 hours.

7. The system of claim 5, wherein the tube length is selected to extend the effective operational life-span of the gas sampling system to greater than 100 hours.

8. The system of claim 3, wherein the valve mechanism includes a shut-off pellet, the shut-off pellet substantially restricting respiratory gas flow upon exposure to the predetermined amount of moisture.

9. The system of claim 8, wherein the shut-off pellet is a hydrophilic pellet.

10. The system of claim 8, wherein the shut-off pellet is a hydrophobic pellet.

11. The system of claim 1, wherein the output dryer tube is comprised of an ionic pore tube dryer.

12. The system of claim 11, wherein the ionic tube dryer includes a Nafionâ

tube dryer.

13. The system of claim 1, wherein the output dryer tube is comprised of a micro-porous tube dryer.

14. The system of claim 1, wherein the output dryer tube is comprised of a molecular sieve dryer.

15. The system of claim 1, wherein the patient respiratory gas output mechanism includes an endotracheal tube.

16. The system of claim 1, wherein the patient respiratory gas output mechanism includes a cannula.

17. The system of claim 16, wherein the cannula is configured to sample CO2.

18. The system of claim 16, wherein the cannula is configured to both sample CO2 and deliver oxygen to a patient.

19. The system of claim 1, wherein the patient respiratory gas output mechanism includes a mask device.

20. The system of claim 1, wherein the patient respiratory gas output mechanism includes a tracheostomy tube.

21. The system of claim 1, wherein the gas sampling tube is comprised of a plastic material.

22. The system of claim 1, wherein the gas sampling tube is comprised of a PVC material.