APPARATUS FOR HEATING BLOOD OR ANOTHER PHYSIOLOGICAL FLUID

Abstract: The invention relates to an apparatus for warming blood or other physiological fluids, comprising a conduit through which the fluid can be conducted, and heating means for warming the fluid flowing through the conduit, the heating means comprising at least one source of infrared radiation, and the conduit being at least partly transparent to the radiation emitted by the infrared source during operation.

Description: > > to D H l-> LΠ o σι o CJ1 O cπ tion. This allows the blood or the fluid to be warmed safely and simply. The efficiency and controllability is aided in particular by the fact that the conduit extends substan- tially in the form of a spiral and that its side facing away from the infrared source is provided with an infrared radiation-reflective coating or film. Such an embodiment of the apparatus according to the invention can, moreover, be produced at relatively low costs. It is desirable that the infrared source be adjustable and connected to a control member, and that the conduit, at its discharge, be provided with a temperature sensor that is coupled to, and feeds the control member. It is further advantageous for the apparatus to be equipped with a flowmeter connected with the control member, in order to be able to accurately adjust the widely varying currents of blood or other physiological fluid that flows through the apparatus . A first embodiment with which this may be real- ized is characterized in that the flowmeter comprises a heat source, and at least one temperatures sensor. A second preferred embodiment is characterized in that the flowmeter comprises two temperature sensors and a heat source positioned between said temperature sensors or near the temperature sensors positioned at the discharge side. The invention will now be further elucidated with reference to the drawings, which in Figure 1, schematically show a longitudinal section of a first preferred embodiment of the apparatus according to the invention; and in Figure 2 , show a top view of the conduit that may be used in a second preferred embodiment of the apparatus according to the invention. The general workings of the apparatus according to the invention will now first be elucidated with reference to Figure 1. The apparatus 1 according to the invention for warming blood or other physiological fluids comprises a conduit 2 , wherein the entrance is indicated by arrow A and the exit by arrow B. Through this conduit 2 the blood or the physiological fluid to be warmed is conducted by means of propulsion, which in itself is known to a person skilled in the art, and which requires no further elucidation at this point. The Figure shows that the conduit 2 is formed like a spiral, and that in the interior of the spiral shape an infrared source is provided, for example, an infrared lamp 3, which serves to warm the blood or another physiological fluid flowing through the conduit 2. For this purpose the conduit 2 is transparent to infrared radiation, at least at the side facing the infrared lamp 3. It is preferred, however, for the side of the conduit 2 facing away from the infrared lamp 3 to be transparent also, and for this latter side to be provided with a heat- reflective coating or film 4. The infrared lamp 3 is preferably adjustable, being connected to a control member 5. Also connected with the control member 5 is a temperature sensor 6, positioned at the discharge side of the conduit 2. In this way the power supply of the adjustable infrared lamp 3 is rendered dependent on the temperature values of the blood or another physiological fluid that leaves the conduit at the discharge side near arrow B. Conveniently there is also a flowmeter 7, 8, 9 connected to the control member 5, to allow the control member 5 to adjust the power supply of the infrared lamp 3 subject to the amount of blood or other physiological fluid being conducted through the conduit 2. A possible embodiment of the flowmeter 7, 8, 9 is one in which a heat source 7 is used, to- gether with one single temperature sensor 8. The flow rate of the blood or fluid can be determined by, with the aid of the heat source 7, supplying the blood or the other physiological fluid entering the conduit 2 near arrow A with heat pulses at a predetermined known frequency, and by measuring these with the aid of the temperature sensor. The Figure shows another embodiment wherein the flowmeter 7, 8, 9 comprises two temperature sensors 8 and 9, and wherein the heat source 7 is positioned between the temperature sensors 8 and 9. The measured temperature differ- ence between the temperature sensors 8 and 9, together with the amount of heat introduced by the heat source 7, determine the flow rate of the blood or the fluid entering the conduit 2 near the arrow A. It should be noted that the heat source 7 may also be positioned near (opposite to) the temperature sensor 8 near the discharge side. The foregoing description is to be understood as being a non-limiting exemplary embodiment of the apparatus according to the invention without limiting the protection merited by the appended claims. The example given merely serves to elucidate said claims. It is, for example, also possible not to embody the conduit 2 as a cylindrical spiral defining a space for housing the infrared lamp 3 but to embody the spiral of the conduit 2 in a plane. A top view of this spiral form of the conduit is shown in Figure 2. Blood or another physiological fluid to be warmed is introduced into the conduit 2 at the entry indicated with arrow A, and leaves the conduit 2 at the exit marked with arrow B. In this em- bodiment the infrared lamp or lamps are positioned next to the conduit 2 in a manner that is completely obvious to the person skilled in the art, and' requires no further elucidation. In correspondence to the afore-described first preferred embodiment, the conduit 2 is, at least at the side of the lamp 3 or lamps, transparent to infrared radiation, and at the side facing away from the infrared lamp or lamps a heat-reflective coating or film may be provided. The infrared lamp or lamps are adjusted in accordance with the manner described for the first preferred embodiment shown in Figure 1. In practice, said second preferred embodiment, in which the conduit 2 is arranged in a plane is for production technical reasons preferred. The blood or the other physiological fluid conducted through said conduit can be warmed safely and the thus embodied apparatus is mechanically simple to realize.

Claims: CLAIMS 1. An apparatus (1) for warming blood or other physiological fluids, comprising a conduit (2) through which the fluid can be conducted, and heating means (3) for warming the fluid flowing through the conduit (2) , characterized in that the heating means comprise at least one source (3) of infrared radiation, and in that the conduit (2) is at least partly transparent to the radiation emitted by the infrared source (3) during operation. 2. An apparatus according to claim 1 characterized in that the conduit defines a space wherein the infrared source is placed, and in that the conduit, at least at the side facing the infrared source, is transparent to infrared radiation. 3. An apparatus according to claim 1, characterized in that the conduit (2) extends substantially in a plane, in that the infrared source (3) is situated next to the conduit (2) , and in that the conduit (2) , at least at the side of the source (3), is transparent. 4. An apparatus according to one of the claims 1-3, characterized in that the conduit (2) extends substantially in the form of a spiral and that its side facing away from the infrared source is provided with an infrared radiation-reflective coating or film (4) . 5. An apparatus according to one of the preceding claims, characterized in that the infrared source (3) is adjustable and connected to a control member (5) , and that the conduit (2) , at its discharge, is provided with a temperature sensor (6) that is coupled to, and feeds the control member (5) . 6. An apparatus according to claim 5, characterized in that the same is equipped with a flowmeter (7, 8, 9) connected with the control member (5) . 7. An apparatus according to claim 6, characterized in that the flowmeter (7, 8, 9) comprises a heat source (7) and at least one temperature sensor (8) . 8. An apparatus according to claim 6 or 7, characterized in that the flowmeter (7, 8, 9) comprises two temperature sensors (8, 9) and a heat source (7) positioned between said temperature sensors (8, 9) or near the tem- perature sensor (8) positioned at the discharge side.

Inventors: BOUHUIJS MENNO CORNELIS, RUTGERS PETRUS THEODORUS, BOUHUIJS, MENNO, CORNELIS, RUTGERS, PETRUS, THEODORUS
Applicants: A J VAN LIEBERGEN HOLDING B V, BOUHUIJS MENNO CORNELIS, RUTGERS PETRUS THEODORUS, A.J. VAN LIEBERGEN HOLDING B.V., BOUHUIJS, MENNO, CORNELIS, RUTGERS, PETRUS, THEODORUS
Application year: 2001
Main classification: A61M5
IPC codes: A61M5