Fluid warmer and method of operating a fluid warmer
First Claim
1. A fluid warmer for temperature control of a medical fluid guided in a fluid tube, the warmer comprising:
- a resistance heating element for alternating voltage, said resistance heating element having a first and a second electrical supply connection conductor, wherein said first electrical supply connection conductor has a first switch and said second electrical supply connection conductor has a second switch;
a heat transfer element which is thermally coupled to said resistance heating element;
a functional grounding conductor, which is electrically conductively connected to said heat transfer element, said functional grounding conductor having a third switch;
a sensor for determining a present magnitude of a leakage current via said functional grounding conductor; and
a control device, said control device being structured to simultaneously switch said first, said second and said third switches into an open switching state within a defined time interval on occurrence of a leakage current that is greater than or equal to a defined maximum threshold current magnitude.
2 Assignments
0 Petitions
Accused Products
Abstract
A fluid warmer (10) for temperature control of a medical fluid (14) guided in a fluid tube (12) and a method for operation thereof have a sensor (38), which determines a leakage current (40) via a functional grounding conductor (FE). Two supply connection conductors (22a; 22b) for a resistance heating element (18) as well as the functional grounding conductor (FE) are each equipped with a switch (30a; 30b; 30c) which can be controlled by a control device (32). The switches (30a; 30b; 30c) can be put into their open switching state jointly within a defined time interval by means of a control device (32) on occurrence of a leakage current (40) that is greater than or equal to a defined maximum threshold current magnitude (ITon, IToff).
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Citations
19 Claims
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1. A fluid warmer for temperature control of a medical fluid guided in a fluid tube, the warmer comprising:
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a resistance heating element for alternating voltage, said resistance heating element having a first and a second electrical supply connection conductor, wherein said first electrical supply connection conductor has a first switch and said second electrical supply connection conductor has a second switch; a heat transfer element which is thermally coupled to said resistance heating element; a functional grounding conductor, which is electrically conductively connected to said heat transfer element, said functional grounding conductor having a third switch; a sensor for determining a present magnitude of a leakage current via said functional grounding conductor; and a control device, said control device being structured to simultaneously switch said first, said second and said third switches into an open switching state within a defined time interval on occurrence of a leakage current that is greater than or equal to a defined maximum threshold current magnitude. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method for operating a fluid warmer for temperature control of a fluid flowing in a fluid tube, the fluid warmer comprising:
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a resistance heating element having a first and a second electrical supply connection conductor for connecting the resistance heating element to an alternating voltage source, the first electrical supply connection conductor having a first switch and the second electrical supply connection conductor having a second switch; a heat transfer element, which is thermally coupled to the resistance heating element for transferring heat to the fluid flowing in a vessel of the fluid tube; a functional grounding conductor connected to the heat transfer element for functional grounding of the heat transfer element, the functional grounding conductor having a third switch; a sensor for sensing a leakage current via the functional grounding conductor; and a control device for controlling the first, second and third switches; the method comprising the steps of; a) defining a maximum threshold current magnitude for a leakage current via the functional grounding conductor; b) comparing a leakage current measured with the sensor with the defined maximum threshold current magnitude; and c) putting the first, second and third switches into open switching states thereof within a defined time interval on occurrence of a leakage current, which is greater than or equal to the defined maximum threshold current magnitude. - View Dependent Claims (19)
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Specification