Anesthetic apparatus

• US 4,538,605 A
• Filed: 03/08/1983
• Issued: 09/03/1985
• Est. Priority Date: 03/18/1982
• Status: Expired due to Fees

• Current Assignee: Gambro Engstrom AB (Baxter International Inc.)
• Original Assignee: Gambro Engstrom AB (Baxter International Inc.)
• Inventors: Odselius, Leif, Gedeon, Andras
• Primary Examiner(s): Recla, Henry J.
• Application Number:
  US06/473,315
• Time in Patent Office: 910 Days
• Field of Search: 128/205.19, 128/205.24, 128/204.26, 128/204.21, 128/204.23, 128/203.29, 128/206.26, 128/910, 128/205.25, 128/205.15, 128/205.16 , 128/205.12
• US Class Current: 128/205.24
• 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 16/22 Carbon dioxide-absorbing devices ; Other means for removing carbon dioxidecartridges with absorbing substances for respiratory apparatus A62B19/00
• CPC Class Codes: Y10S 128/91 Anesthesia gas scavenging system

Abstract

An anesthetic apparatus for administering a gaseous anesthetic comprises a breathing mask which is connected to the inspiration pipe and the expiration pipe of the apparatus and used for connecting the apparatus to the airways of a patient. To prevent harmful gaseous anesthetic from being released to the surroundings when the mask is temporarily lifted from the patient'"'"'s face during anesthesia in order to check the condition of the patient, the apparatus is provided with a gas suction device which can be connected to the mask through a controllable valve. The gas suction device may be continuously operated or may be started automatically when the valve is opened. A signal emitter for generating control signals and applying these to the valve is arranged on, or in the vicinity of the mask in a manner such that it can either be activated manually by the anesthetist, or is activated automatically when the mask is lifted from the patient'"'"'s face, at which time it generates a control signal for opening the valve. In this way, the suction device is connected with both the inspiration pipe of the anesthetic apparatus and with the mask, whereby all gaseous anesthetic supplied through the inspiration pipe is removed by suction, and also at least the major part of the gas exhaled by the patient is caught and removed by suction through the mask. The suction device has a capacity which at least corresponds to, and preferably exceeds, the maximum flow of gaseous anesthetic capable of being delivered by the anesthetic apparatus any one moment in time.

Claims

1. An anesthetic apparatus comprising an inspiration line and an expiration line, a breathing mask connected to one end of said inspiration line and said expiration line respectively, and adapted for placement over the face of a patient for connecting the airways of the patient to said inspiration and expiration lines, a ventilator unit connected to the opposite ends of said inspiration and expiration lines for supplying gaseous anesthetics to said inspiration line and for receiving gas exhaled by the patient from said expiration line, an inspiration valve in said inspiration line permitting a gas flow only in a direction towards said breathing mask, an expiration valve in said expiration line permitting a gas flow only in a direction away from said breathing mask, a gas suction device having a capacity at least corresponding to the greatest flow of gas which said ventilator unit can supply to said inspiration line at any given time, said gas suction device including a suction side through which suction may be applied, valve means connecting the suction side of said gas suction device to one of said expiration and inspiration lines at a point closer to said breathing mask than said expiration valve and inspiration valve respectively, control means for operating said valve means between a closed state and an open state in response to the position of said breathing mask relative to the face of the patient so that said valve means is in said closed state when the breathing mask is pressed against the face of the patient and is in said open state when said breathing mask is lifted from the face of the patient.

2. An apparatus as claimed in claim 1, wherein said control means for said valve means include pneumatic means responsive to a pneumatic control pressure so as to hold said valve means in said closed state when said pneumatic control pressure exceeds a predetermined value and to release said valve means to said open state when said pneumatic control pressure is lower than said predetermined value.

3. An apparatus as claimed in claim 2, wherein said breathing mask is provided with a hollow, air-filled sealing bead along the edge of the mask intended to abut the face of the patient, a pneumatic line being connected between said sealing bead and said pneumatic control means for conveying the air pressure within said sealing bead as said pneumatic control pressure to said pneumatic control means.

4. An apparatus as claimed in claim 1, comprising an under-pressure valve connected to the suction side of said suction device between said valve means and said suction device for connecting the suction side of the suction device to the ambient atmosphere, if the pressure on the suction side of the suction device falls below a predetermined minimum value.