Method for measuring the anesthetic agent consumption in a ventilation system

• US 20080029092A1
• Filed: 05/31/2007
• Published: 02/07/2008
• Est. Priority Date: 06/10/2006
• Status: Active Grant

• Current Assignee: Dragerwerk AG & Company KGaA (FPS Vermögensverwaltung GmbH)
• Original Assignee: Drager Medical AG & Co KG (Dragerwerk AG)
• Inventors: Heesch, Ralf
• Granted Patent: US 9,770,569 B2
• Time in Patent Office: Days
• US Class Current: 128/203.14
• CPC Class Codes: A61M 16/0063 Compressors
• CPC Class Codes: A61M 16/0072 Tidal volume piston pumps
• CPC Class Codes: A61M 16/01 specially adapted for anaesthetising A61M16/104, A61M16/18 take precedence
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/10 Preparation of respiratory gases or vapours
• CPC Class Codes: A61M 16/104 specially adapted for anaesthetics A61M16/18 takes precedence
• CPC Class Codes: A61M 16/12 by mixing different gases
• CPC Class Codes: A61M 16/18 Vaporising devices for anaesthetic preparations
• CPC Class Codes: A61M 16/22 Carbon dioxide-absorbing devices ; Other means for removing carbon dioxidecartridges with absorbing substances for respiratory apparatus A62B19/00
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2016/0042 in the expiratory circuit
• CPC Class Codes: A61M 2016/102 Measuring a parameter of the content of the delivered gas
• CPC Class Codes: A61M 2016/1025 the O2 concentration
• CPC Class Codes: A61M 2016/103 the CO2 concentration
• CPC Class Codes: A61M 2016/1035 the anaesthetic agent concentration

Abstract

A method for measuring the anesthetic agent consumption in a ventilation system has a breathing circuit which contains a gas mixer (1) and an anesthetic agent metering device (2). The anesthetic agent quantity, which is consumed over a pregiven time interval in the ventilation system, is determined from the sum of the determined anesthetic gas volume flows in the ventilation system which are integrated over the pregiven time interval.

Claims

1. A method for measuring consumption of an anesthetic agent in a ventilation system having a breathing circuit containing a gas mixer and an anesthetic agent metering device, the method comprising the method steps of:

determining anesthetic gas volume flows in said ventilation system and integrating said gas volume flows over a pregiven time interval; and

,

determining a quantity of said anesthetic agent consumed over said pregiven time interval from the sum of said anesthetic gas volume flows in said ventilation system.

2. The method of claim 1, wherein the anesthetic gas volume flows in said ventilation system are measured.

3. The method of claim 1, comprising the further step of determining at least one of the anesthetic gas volume flows from the measured volume flow multiplied by the anesthetic gas concentration corresponding to said volume flow.

4. The method of claim 3, wherein said anesthetic gas concentration is either the absolute measured value or the difference value of the anesthetic gas concentration in said volume flow, which is supplied to a component, less the anesthetic gas concentration which is drawn away from said component.

5. The method of claim 1, wherein the quantity of said anesthetic agent is determined from the anesthetic gas volumes determined by integration utilizing anesthetic agent specific characteristic data dependent upon pressure and temperature with said data being stored in a control and computer unit.

6. The method of claim 4, wherein the difference of inspiratory and expiratory breathing volume flows, which are measured at the patient, is used as a component part for the measurement of the anesthetic agent consumption so that an anesthetic agent uptake of the patient is determined hereby.

7. The method of claim 1, wherein the differences of the anesthetic gas volume flows are measured upstream and downstream of the anesthetic gas losses in the ventilation system.

8. The method of claim 7, wherein the anesthetic gas losses are local anesthetic agent consumers in the ventilation system.

9. The method of claim 8, wherein said consumers include all elements in said ventilation system whereat anesthesia gas is consumed.

10. The method of claim 9, wherein said elements include the patient, leaks in the system and gas volumes leaving the system including via an anesthetic gas conducting line valve.

11. The method of claim 6, wherein the correlation between the surplus consumed anesthetic gas volume flow and the anesthetic agent metering adjusted at the anesthetic agent metering device is displayed graphically.

12. The method of claim 11, wherein the surplus consumed volume flow is conducted away by the anesthetic gas conducting line.