Abstract:
A method for absorbing an anesthetic, heat and moisture in an anesthesia system is disclosed herein. The method includes providing a first material configured to absorb an anesthetic transferred from a patient. The method also includes providing a second material configured to absorb heat and moisture transferred from the patient. The method also includes combining the first material with the second material in order to produce a single composite material adapted to generally simultaneously absorb the anesthetic, heat and moisture.

Description:
FIELD OF THE INVENTION 
       [0001]    This disclosure relates generally to a method and system for conserving anesthesia, heat and moisture. 
       BACKGROUND OF THE INVENTION 
       [0002]    Anesthesia may be administered to a patient in the form of a gas for purposes such as blocking the conscious perception of pain, producing unconsciousness, preventing memory formation, and/or preventing unwanted movement. The administered anesthetic agent is inhaled into the patient&#39;s lungs. Thereafter, the patient absorbs a fraction of the administered anesthetic agent and exhales the remainder. One problem is that the anesthetic agent is expensive and it is therefore costly to waste the exhaled anesthetic agent. Additionally, the exhaled anesthetic agent can pose a health risk to nearby personnel and may be environmentally unsafe. 
         [0003]    In addition to exhaling anesthetic agent, the patent also expels heat and moisture. This loss of heat and moisture can lower the patient&#39;s body temperature and can dry out the patient&#39;s respiratory tract. These effects can cause discomfort and can increase the potential for complications or other health concerns. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0004]    The above-mentioned shortcomings, disadvantages and problems are addressed herein which will be understood by reading and understanding the following specification. 
         [0005]    In an embodiment, a method for conserving anesthetic, heat and moisture in an anesthesia system includes providing a first material configured to absorb an anesthetic transferred from a patient. The method also includes providing a second material configured to absorb heat and moisture transferred from the patient. The method also includes combining the first material with the second material in order to produce a single composite material adapted to generally simultaneously absorb the anesthetic, heat and moisture. 
         [0006]    In another embodiment, an absorber for an anesthesia system includes a first material configured to absorb an anesthetic transferred from a patient. The absorber also includes a second material engaged with the first material. The second material is configured to absorb heat and moisture transferred from the patient. The first material and the second material are combined in a manner configured to provide generally simultaneous absorption of the anesthetic, heat and moisture. 
         [0007]    In another embodiment, an anesthesia system includes a vaporizer configured to convert a liquid anesthetic agent into a gaseous anesthetic agent, and a breathing tube in communication with the vaporizer. The breathing tube is configured to transfer the gaseous anesthetic agent to a patient. The anesthesia system also includes an absorber in communication with the patient. The absorber is disposed remotely relative to the vaporizer. The absorber includes a first material comprising carbon. The first material is configured to absorb the gaseous anesthetic agent transferred from the patient. The absorber also includes a second material engaged with said first material. The second material is configured to absorb heat and moisture transferred from the patient. The first material and the second material are combined in a manner configured to provide generally simultaneous absorption of the anesthetic, heat and moisture. 
         [0008]    Various other features, objects, and advantages of the invention will be made apparent to those skilled in the art from the accompanying drawings and detailed description thereof. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a schematic diagram illustrating a anesthesia system including an absorber in accordance with an embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0010]    In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments that may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments, and it is to be understood that other embodiments may be utilized and that logical, mechanical, electrical and other changes may be made without departing from the scope of the embodiments. The following detailed description is, therefore, not to be taken as limiting the scope of the invention. 
         [0011]    Referring to  FIG. 1 , an anesthesia system  8  is schematically depicted in accordance with one embodiment. The anesthesia system  8  includes an anesthesia machine  10 , a plurality of gas storage devices  12   a ,  12   b  and  12   c , an absorber  26 , a vaporizer  28 , and a scavenger system  38 . The anesthesia machine  10  is shown for illustrative purposes and it should be appreciated that other types of anesthesia machines may alternately be implemented. In a typical hospital environment, the gas storage devices  12   a ,  12   b  and  12   c  are centrally located storage tanks configured to supply medical gas to multiple anesthesia machines and multiple hospital rooms. The storage tanks are generally pressurized to facilitate the transfer of the medical gas to the anesthesia machine  10 . 
         [0012]    The gas storage devices  12   a ,  12   b  and  12   c  will hereinafter be described as including an air tank  12   a , an oxygen (O 2 ) tank  12   b , and a nitrous oxide (N 2 O) tank  12   c , respectively, however it should be appreciated that other storage devices and other types of gas may alternatively be implemented. The gas storage tanks  12   a ,  12   b  and  12   c  are each connected to one of the gas selector valves  14   a ,  14   b , and  14   c , respectively. The gas selector valves  14   a ,  14   b  and  14   c  may be implemented to shut off the flow of medical gas from the storage tanks  12   a ,  12   b  and  12   c  when the anesthesia machine  10  is not operational. When one of the gas selector valves  14   a ,  14   b  and  14   c  is opened, gas from a respective storage tank  12   a ,  12   b  and  12   c  is transferred under pressure to the anesthesia machine  10 . 
         [0013]    The anesthesia machine  10  includes a gas mixer  16  adapted to receive medical gas from the storage tanks  12   a ,  12   b  and  12   c . The gas mixer  16  includes a plurality of control valves  18   a ,  18   b  and  18   c  that are respectively connected to one of the gas selector valves  14   a ,  14   b  and  14   c . The gas mixer  16  also includes a plurality of flow sensors  20   a ,  20   b  and  20   c  that are each disposed downstream from a respective control valve  18   a ,  18   b , and  18   c . After passing through one of the control valves  18   a ,  18   b  and  18   c , and passing by one of the flow sensors  20   a ,  20   b  and  20   c , the individual gasses (i.e., air, O 2  and N 2 O) are combined to form a mixed gas at the mixed gas outlet  22 . 
         [0014]    The control valves  18   a ,  18   b  and  18   c  and the flow sensors  20   a ,  20   b  and  20   c  are each connected to a controller  24 . The controller  24  is configured to operate the control valves  18   a ,  18   b  and  18   c  in a response to gas flow rate feedback from the sensors  20   a ,  20   b  and  20   c . Accordingly, the controller  24  can be implemented to maintain a selectable flow rate for each gas (i.e., air, O 2  and N 2 O) such that the mixed gas at the mixed gas outlet  22  comprises a selectable ratio of air, O 2  and N 2 O. The mixed gas flows through an absorber  26  to a vaporizer  28  where an anesthetic agent  30  is vaporized and added to the mixed gas from the mixed gas outlet  22 . The anesthetic agent  30  and mixed gas combination passes through a breathing tube  32  and is delivered to the patient  34 . Although the vaporizer  28  and anesthetic agent  30  are schematically depicted as being separate components of the anesthesia system  8 , it should be appreciated that one or both of these components may alternatively be incorporated into the design of the anesthesia machine  10 . 
         [0015]    A fraction of the anesthetic agent  30  administered to the patient  34  is absorbed into the patient&#39;s blood stream, and the remainder is expelled as the patient  34  exhales. The exhaled anesthetic agent  30  is transferred via the breathing tube  32  back to the absorber  26 . A portion of the exhaled anesthetic agent  30  can be collected by the absorber  26  and re-directed back to the patient  34  during a subsequent inhalation. The absorber  26  is similarly configured to collect and re-direct exhaled heat and moisture as will be described in detail hereinafter. Advantageously, the absorber  26  configured in the manner described recycles anesthetic agent  30  as a cost savings measure, and also limits the patient&#39;s loss of heat and moisture in order to maintain patient comfort and to minimize the risk of complications. The uncollected exhaled anesthetic agent  28  is transferred through the scavenger tube  36 , into the scavenger system  38  and is released into the atmosphere where it becomes diluted with outside air to the extent that it is no longer dangerous. 
         [0016]    According to one embodiment, the absorber  26  comprises activated carbon  26   a  combined with a fibrous material  26   b . The activated carbon  26   a  is adapted to absorb anesthetic agent  30  exhaled from the patient  34 . The fibrous material  26   b  is adapted to absorb moisture exhaled from the patient  34 . The process of absorbing moisture also absorbs heat from the patient  34 . Accordingly, the absorber  26  provides a single composite material configured to generally simultaneously absorb anesthetic agent  30 , heat and moisture exhaled by the patient  34 . The following describes several exemplary absorber  26  compositions and methods of manufacture in detail. 
         [0017]    According to one exemplary embodiment, the absorber  26  includes an activated carbon  26   a  that is comprised of an activated carbon powder, and a fibrous material  26   b  that is comprised of cellulose paper. The cellulose paper is saturated with water, and the activated carbon powder is applied to the cellulose paper while the cellulose paper is still wet. The moisture causes the activated carbon powder to adhere to the saturated cellulose paper. Thereafter, the absorber  26  of the present exemplary embodiment is allowed to dry such that at least a portion of the activated carbon powder remains in contact with the cellulose paper. 
         [0018]    According to another exemplary embodiment, the absorber  26  includes an activated carbon  26   a  that is comprised of activated carbon fibers, and a fibrous material  26   b  that may, for example, comprise cellulose. The activated carbon fibers may then be interwoven with the fibrous material  26 . 
         [0019]    According to yet another exemplary embodiment, the absorber  26  includes an activated carbon  26   a  that is initially comprised of regular non-activated carbon fibers, and a fibrous material  26   b  that may, for example, comprise cellulose. The non-activated carbon fibers are interwoven with the fibrous material  26  and are thereafter activated according to a known industrial process. The industrial process by which the non-activated carbon fiber is activated is well known to those skilled in the art and will therefore not be described in detail. 
         [0020]    According to still another exemplary embodiment, the absorber  26  includes an activated carbon  26   a  that is comprised of activated carbon fibers, and a fibrous material  26   b  that is comprised of a polymer. The activated carbon fibers can be woven together and applied to the polymer such as with adhesive thereby creating a fibrous network of both activated carbon and polymer. 
         [0021]    While the invention has been described with reference to preferred embodiments, those skilled in the art will appreciate that certain substitutions, alterations and omissions may be made to the embodiments without departing from the spirit of the invention. Accordingly, the foregoing description is meant to be exemplary only, and should not limit the scope of the invention as set forth in the following claims.