Anesthetic filter arrangement with variable retention of gas by the filter

• US 20020104542A1
• Filed: 12/10/2001
• Published: 08/08/2002
• Est. Priority Date: 01/10/2001
• Status: Active Grant

• Current Assignee: Maquet Critical Care AB (Getinge AB)
• Original Assignee: Siemens Elema AB
• Inventors: Castor, Rolf, Videbrink, Petter
• Granted Patent: US 6,745,771 B2
• Time in Patent Office: Days
• US Class Current: 128/205.27
• CPC Class Codes: A61M 16/009 Removing used or expired gases or anaesthetic vapours filtering, sterilising or disinfecting the exhaust air in drainage systems A61M1/784; bacterial filters in the expiratory path A61M16/1065
• CPC Class Codes: A61M 16/0093 by adsorption, absorption or filtration
• CPC Class Codes: A61M 16/104 specially adapted for anaesthetics A61M16/18 takes precedence
• CPC Class Codes: A61M 16/1065 in the expiratory path
• CPC Class Codes: A61M 16/107 in the inspiratory path
• CPC Class Codes: A61M 16/109 the humidifying liquid or the beneficial agent
• CPC Class Codes: A61M 16/18 Vaporising devices for anaesthetic preparations
• CPC Class Codes: A61M 2016/0036 in the breathing tube and used in both inspiratory and expiratory phase
• CPC Class Codes: A61M 2016/1035 the anaesthetic agent concentration

Abstract

An anesthetic filter arrangement has a filter housing with openings disposed to delimit a gas flow path inside the housing for gas passing to and from a patient, and having disposed within the gas flow path a filter element formed of an adsorption material for the alternate adsorption and desorption of gaseous anesthetic from and into gas passing along the gas flow path respectively from and to the patient. An energy source is provided to supply thermal and/or vibrational energy at the filter element to vary retention of the gaseous anesthetic by the filter element.

Claims

1. An anesthetic filter arrangement comprising:

a filter housing having openings therein disposed to delimit a gas flow path in an interior of the housing adapted to receive gas, including a gaseous anesthetic, passing to and from a patient in said gas flow path;

a filter element disposed in said gas flow path in said housing, said filter element being comprised of an adsorption material for alternatingly adsorbing said gaseous anesthetic from said gas in said gas flow path and desorbing said gaseous anesthetic into said gas in said gas flow path; and

an energy source in energy transferring communication with said filter element for supplying energy to said filter element to vary retention of said gaseous anesthetic by said filter element.

2. A filter arrangement as claimed in claim 1 wherein said energy source supplies energy to said filter element to vary a temperature of said filter element to vary said retention of the gaseous anesthetic by the filter element.

3. A filter arrangement as claimed in claim 2 wherein said energy source comprises an electrical resistive heater disposed in thermal contact with said filter element.

4. A filter arrangement as claimed in claim 2 wherein said adsorption material is electrically conductive, and wherein said energy source comprises an electric power supply which supplies electric power to said adsorption material.

5. A filter arrangement as claimed in claim 1 wherein said energy source supplies vibrational energy to said filter element to vary said retention of the gaseous anesthetic by the filter element.

6. A filter arrangement as claimed in claim 5 wherein said energy source is an ultrasound emitter which directs ultrasonic vibrational energy toward said filter element.

7. A filter arrangement as claimed in claim 1 wherein said gas in said gas flow path has a variable gas flow, and wherein said energy source supplies energy to said filter element to synchronize said retention of said gaseous anesthetic by said filter element with said variable gas flow.

8. A filter arrangement as claimed in claim 7 further comprising a flow meter disposed in said gas flow path for monitoring said gas flow, said flow meter being operably connected to said energy source and supplying an output signal to said energy source indicative of said gas flow, and wherein said energy source varies the supply of energy to said filter element dependent on said output from said flow meter.

9. A filter arrangement as claimed in claim 7 wherein said gas flow includes a phase wherein gas is adapted to flow in said gas flow path in a direction toward a patient, and wherein said energy source supplies energy to said filter material during said phase to promote desorption of previously adsorbed anesthetic gas from said filter element into the gas in the gas flow path.

10. A filter arrangement as claimed in claim 9 wherein said energy source is controlled to supply energy to said filter element at a commencement of said phase of said gas flow.

11. A filter arrangement as claimed in claim 7 wherein said gas flow includes a phase wherein gas is adapted to flow in said gas flow path in a direction away from a patient, and wherein said energy source is controlled to supply energy to said filter element to inhibit absorption of said anesthetic gas by said filter element during said phase.

12. An inhalation anesthesia system comprising:

a mechanical breathing aid for supplying a breathing gas, including an anesthetic gas, adapted to ventilate a patient in an inspiration phase and an expiration phase;

a gas circuit connected to the breathing aid and adapted for connection to a patient for conducting said breathing gas to a patient during said inspiration phase and for conducting exhaled gas from a patient during said expiration phase;

a filter housing connected in said gas circuit, said filter housing having openings therein which delimit a gas flow path through said housing for said breathing gas;

a filter element disposed in said gas flow path in said housing, said filter element being comprised of absorption material; and

an energy source in energy transferring communication with said filter element for causing said adsorption material to alternatingly adsorb said gaseous anesthetic in said gas flow path from said breathing gas in said expiration phase and desorb said gaseous anesthetic into said breathing gas in said gas flow path during said inspiration phase.