Flexible heat exchanger

Abstract

The present invention relates to a heat exchanger which comprises a flexible sheet consisting of a porous material, such as polyvinyl alcohol, sandwiched between two liquid impermeable layers, the liquid impermeable layers defining between them and between fluid-tight edges, a liquid transfer space within said sheet and at least one liquid inlet and at least one liquid outlet for respective connection to a source and a drain of a heat transfer liquid, with a flow path defined between the liquid inlet and liquid outlet within said liquid transfer space. According to one embodiment, the heat exchanger is comprised of an internal PVA sheet sandwiched between two layers of adherent, film forming material. According to one preferred embodiment, the film forming material is silicon. The heat exchanger of the present invention is preferably formed into a garment for overlaying a substantial portion of a subject's body, for controlling its body temperature.

Description

[0001] The present invention relates to a heat exchanger.BACKGROUND OF THE INVENTION AND PRIOR ART[0002] Most heat exchangers hitherto known are used for controlling the temperature of a variety of elements found in manufacturing industry, the process industry, buildings, vehicles, agriculture, medical equipment etc. Heat exchangers are found in many different configurations, however, most are characterized by rigid constructions, typically metal made and having simple geometric shapes.[0003] One application of heat exchangers is during medical procedures, where a subject's body temperature has to be controlled. For example, during open heart surgery, the body temperature has to be controllably reduced to about 35.degree. C. and then at the end of the operation increased back to normal body temperature. Furthermore, under general anesthesia, the natural physiological mechanisms which operate to maintain a body temperature may fail, and the problem becomes particularly acute in cases...

AI Technical Summary

Benefits of technology

[0016] This new design of a heat exchanger has certain new features which give rise to new potential uses in the different areas hitherto known to make use of heat exchangers. These features include, inter alia, flexibility and elasticity, hence the ability to conform to irregular shapes; low cost, therefore disposable, high corrosion resistance and capable of being produced in large area formats and in any shape.

[0018] The impermeable layer should be formed such that it will not impair the porous sheet's flexibility and elasticity, among other of its features.

[0020] The porosity of the liquid transfer space causes the liquid to assume a tortuous path within the pores of the porous sheet, which causes the liquid to essentially evenly distribute within the liquid transfer space. However, in accordance with one preferred embodiment, in order to ensure a more homogenous flow of liquid throughout the space, several liquid inlets may be provided at different locations to define together a moving liquid front (such a front consisting of liquid exiting from the openings at about the same time). In accordance with another preferred embodiment, said at least one liquid inlet and said at least one liquid outlet comprise a respective feed and drain manifold. The feed and drain manifolds are another measure to improve distribution of the liquid within the liquid transfer space.

Problems solved by technology

Furthermore, under general anesthesia, the natural physiological mechanisms which operate to maintain a body temperature may fail, and the problem becomes particularly acute in cases where exposed internal body organs come into contact with the ambient air which results in excessive heat loss.

This problem is further aggravated by the fact that operating rooms are very often heavily cooled.

Similarly to human subjects, the problem of controlling body temperature is also experienced during surgical procedures performed on animals.

Overall, controlling the body temperature is one of the serious problems facing the medical staff when performing operations.

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