Surgery – Respiratory method or device – Means for mixing treating agent with respiratory gas
Patent
1998-10-01
2000-12-05
Lewis, Aaron J.
Surgery
Respiratory method or device
Means for mixing treating agent with respiratory gas
12820312, A61M 1500
Patent
active
061552550
DESCRIPTION:
BRIEF SUMMARY
FIELD OF INVENTION
According to a first aspect, the present invention relates to a vaporizer of the kind defined in the preamble of Claim 1. According to a second aspect, the invention relates to the particular use of such a vaporizer, and in accordance with a third aspect the invention relates to a liquid vaporizing method of the kind defined in the preamble of Claim 14.
Although the invention can be applied in several different ways, it finds particular use in the anaesthesia of patients, in which case the inventive vaporizer is adapted for connection to a system of hoses and apparatus that deliver breathing gas to a patient and that supply vaporized anaesthetic to respective patients.
DESCRIPTION OF THE BACKGROUND ART
Anaesthetic vaporizers are well known in the art and a large number of different methods of application are described in the literature. For a better understanding of the known and used vaporizers, reference is made to Anaesthetic Equipment, C. S. Ward, publisher Bailliere Tindall, 2nd edition, 1987, pp. 78-103, and to Anesthesia Vaporizers by J. B. Eisenkraft in Anesthesia Equipment, principles and applications, authors Jan Ehrenwerth, James B. Eisenkraft, publisher Mosby 1993, pp. 57-58.
The earlier described vaporizers are based on the principle of storing the liquid anaesthetic in a container. A breathing gas is introduced into this container and caused to pass over the surface of the liquid or to percolate therethrough.
Some of the anaesthetic is vaporized during passage of the breathing gas and therewith delivered to the patient together with the gas. This method, however, is encumbered with a large number of problems. liquid, therewith cooling the gas. This cooling of the gas can result in a change in the vapor pressure across the liquid, and therewith in changes in the amount of anaesthetic that is entrained with the breathing gas. number of constructions or, in the case of temperature-sensitive systems, the amount of breathing gas that passes across the liquid surface is varied and different gas flows are then combined so as to obtain a constant anaesthetic concentration in the breathing gas. breathing gas. It has been endeavored to compensate for this dependency, by including different intricate flow-dependent valves and gas mixing systems in the vaporizer. This flow dependency can cause problems, particularly in the case of low fresh-gas inlet flows used in so-called low flow systems. must be applied in given concentrations for optimal anaesthesia. Attempts have been made to compensate for this, by designing individual vaporizers for solely one anaesthetic. One serious drawback in this regard is that erroneous filling of a given vaporizer with an anaesthetic for which the vaporizer is not intended can have catastrophic effects. The requirement of several different vaporizers mounted together on an anaesthesia machine also introduces the risk of all vaporizers being in operation simultaneously, with the danger of overdosing the anaesthetic. mixtures. This can result in administering to the patient an anaesthetic concentration that is different to the concentration for which the vaporizer is set, due to the composition of the gas mixture. the anaesthetic. The anaesthetic is sucked up by the wick and vaporized on its surface. One drawback with this system, however, is that the suction rate is dependent on the height and temperature of the liquid surface, whereby the vaporizer must include a compensating system.
DE-A 4 105 163 teaches an anaesthetic vaporizing system in which a porous body is saturated with anaesthetic and through which the anaesthetizing gases pass.
One drawback with this system is that the total quantity of anaesthetic to be used is limited to the absorbency of the porous body. Another drawback is that evaporation of the anaesthetic in the by-passing gas will vary with time, due to lowering of the temperature of the body among other things (this lowering of temperature being caused by gas evaporation). The system must therefore include a separate temperature c
REFERENCES:
patent: 3540445 (1970-11-01), Moyat
patent: 4015599 (1977-04-01), Peterson
patent: 4059657 (1977-11-01), Hay
patent: 4454879 (1984-06-01), Peterson
patent: 5293865 (1994-03-01), Altner et al.
patent: 5337738 (1994-08-01), Heinonen
patent: 5490500 (1996-02-01), Reichert et al.
patent: 5664561 (1997-09-01), Kersey
patent: 5730119 (1998-03-01), Lekholm
Lewis Aaron J.
Louis Gibeck AB
Mitchell Teena
LandOfFree
Vaporizer, use of such vaporizer and a method for vaporizing a l does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Vaporizer, use of such vaporizer and a method for vaporizing a l, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vaporizer, use of such vaporizer and a method for vaporizing a l will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-951799