Method for controlling a disinfection status of a temperature control device and temperature control device for human body temperature control during extracorporeal circulation

Abstract

The present application relates to a method for controlling a disinfection status of a heater and/or cooler for human body temperature control during extracorporeal circulation. The temperature control is conducted by use of a heat exchanger and a temperature control liquid circulating through the heat exchanger and the heater and/or cooler. The inventive method comprises using a long term disinfectant in the temperature control liquid, measuring and preferably recording the concentration of the disinfectant in the temperature control liquid and deducing a disinfectant status of the temperature control liquid from the measured concentration of the disinfectant in the temperature control liquid.

Claims

.[.1. A method for controlling a disinfection status of a temperature control device for human body temperature control during extracorporeal circulation, wherein temperature control is achieved by use of the temperature control device that circulates the temperature control liquid through a heat exchanger, the method comprising: measuring a concentration of a disinfectant in the temperature control liquid continuously during the extracorporeal circulation; generating by a computer a disinfection status of the disinfectant from the measured concentration to be one of sufficiently disinfected, minor contamination, and change temperature control liquid; and generating by the computer an adjustment recommendation in response to the disinfection status during the extracorporeal circulation..].

.[.2. The method of claim 1, wherein measuring a concentration comprises measuring the concentration of the disinfectant in the temperature control liquid via a disinfectant sensor..].

.[.3. The method of claim 2, wherein the disinfectant sensor is situated in the temperature control device..].

.[.4. The method of claim 2, wherein the disinfectant sensor provides an electric signal in accordance with the concentration of the disinfectant..].

.[.5. The method of claim 1, wherein generating the disinfection status comprises: assigning the disinfection status to sufficiently disinfected if the concentration of the disinfectant is at least a first concentration; assigning the disinfection status to minor contamination if the concentration of the disinfectant is between the first concentration and a second concentration; and assigning the disinfection status to change temperature control liquid if the concentration of the disinfectant is less than or equal to the second concentration..].

.[.6. The method of claim 1, further comprising: recording the concentration of the disinfectant and determining a rate of reduction of the concentration of the disinfectant in the temperature control liquid..].

.[.7. The method of claim 1, wherein the disinfectant comprises at least one of hydrogen peroxide, sodium hypochlorite and citric acid..].

.[.8. The method of claim 1, wherein the temperature control liquid includes water..].

.[.9. The method of claim 1, wherein generating the adjustment recommendation if the disinfection status is minor contamination comprises indicating adding disinfectant to the temperature control liquid to increase the concentration of the disinfectant in the temperature control liquid to at least the first concentration..].

.[.10. The method of claim 1, wherein generating the adjustment recommendation if the disinfection status is change temperature control liquid comprises indicating changing the temperature control liquid and disinfecting the temperature control device with disinfectant having a third concentration that is greater than the first concentration..].

.[.11. The method of claim 1, wherein the temperature control liquid is provided from and returned to a reservoir..].

.[.12. The method of claim 1, further comprising: indicating the concentration of the disinfectant on a first display connected to the temperature control device..].

.[.13. The method of claim 1, further comprising: indicating the disinfectant status on a second display connected to the temperature control device..].

.[.14. A method for controlling a disinfection status of a temperature control device for human body temperature control during extracorporeal circulation, wherein temperature control is achieved by use of the temperature control device that circulates a temperature control liquid through a heat exchanger, the method comprising: measuring and recording a concentration of a disinfectant in the temperature control liquid continuously during the extracorporeal circulation; calculating by a computer a rate of reduction of the concentration of the disinfectant in the temperature control liquid during the extracorporeal circulation; and determining a level of contamination based on the rate of reduction of the concentration..].

.[.15. The method of claim 14, comprising: determining a disinfection status of the temperature control liquid from the concentration of the disinfectant in the temperature control liquid..].

.[.16. The method of claim 14, wherein measuring the concentration includes use of a disinfectant sensor..].

.[.17. The method of claim 14, further comprising: generating a disinfection status of the disinfectant from the measured concentration to be one of sufficiently disinfected, minor contamination, and change temperature control liquid..].

.[.18. The method of claim 17, further comprising: generating an adjustment recommendation in response to the disinfection status during the extracorporeal circulation..].

.[.19. A system including a temperature control device for human body temperature control during extracorporeal circulation, which can be connected to a heat exchanger and is configured for heating and/or cooling a temperature control liquid to be circulated through the heat exchanger for achieving the human body temperature control, the system comprising: a disinfectant sensor configured to measure a concentration of a disinfectant in the temperature control liquid during the extracorporeal circulation; a computer configured to receive the measured concentration, generate a disinfection status of the temperature control liquid, the disinfection status being from a group including a first status, a second status, and a third status, and generate an adjustment recommendation in response to the disinfection status during the extracorporeal circulation; and at least one display controlled by the computer to indicate the disinfection status and the adjustment recommendation..].

.[.20. The system of claim 19, wherein the disinfectant sensor is situated in the temperature control device..].

.[.21. The system of claim 19, wherein the heat exchanger comprises a blood side circulating blood and a liquid side circulating the temperature control liquid separate from each other and configured to exchange only heat..].

.Iadd.22. A method for inhibiting microbial growth in a human body temperature control system used during extracorporeal circulation, wherein temperature control is achieved by use of a circulating temperature control liquid, the method comprising: connecting a single-use heat exchanger to a circuit of temperature control liquid connected to a temperature control device including a disinfectant sensor, wherein the temperature control liquid is provided from and returned to an open air reservoir; circulating the temperature control liquid through the heat exchanger and the temperature control device, each of the heat exchanger and the temperature control liquid disposed at separate locations, wherein the temperature control liquid includes a disinfectant to inhibit microbial growth in the temperature control system; generating a disinfection status of the disinfectant from a concentration of disinfectant measured by the sensor to be one of sufficiently disinfected, minor contamination, and change temperature control liquid; circulating blood from the human body through the heat exchanger, such that the blood enters the heat exchanger through a blood inlet disposed substantially perpendicular to a flow of the temperature control liquid; and disconnecting and disposing the heat exchanger..Iaddend.

.Iadd.23. The method of claim 22, wherein the disinfectant is one or more of the group including hydrogen peroxide, sodium hypochlorite and citric acid..Iaddend.

.Iadd.24. The method of claim 22, wherein the temperature control liquid includes the disinfectant and water..Iaddend.

.Iadd.25. The method of claim 22, wherein the temperature control liquid includes the disinfectant in a concentration of from 200 to 300 mg/I..Iaddend.

.Iadd.26. The method of claim 22, wherein generating the disinfection status comprises: assigning the disinfection status to sufficiently disinfected if the concentration of the disinfectant is at least a first concentration; assigning the disinfection status to minor contamination if the concentration of the disinfectant is between the first concentration and a second concentration; and assigning the disinfection status to change temperature control liquid if the concentration of the disinfectant is less than or equal to the second concentration..Iaddend.

.Iadd.27. The method of claim 22, further comprising recording the concentration of the disinfectant and determining a rate of reduction of the concentration of the disinfectant in the temperature control liquid..Iaddend.

.Iadd.28. A human body temperature control system for heating and/or cooling blood from a human body during extracorporeal circulation, the system comprising: a temperature control device for heating and/or cooling a temperature control liquid; a single-use heat exchanger separate from and connectable to the temperature control device and disposed at a location separate from the temperature control device, the heat exchanger adapted for exchanging heat between the blood and the temperature control liquid, wherein the heat exchanger includes a blood inlet disposed substantially perpendicular to a flow of the temperature control liquid; and a disinfectant sensor; wherein the temperature control liquid is provided from and returned to an open air reservoir; wherein the heat exchanger includes a liquid side configured for circulating the temperature control liquid through the heat exchanger and the temperature control device; wherein the heat exchanger includes a blood side for circulating the blood from the human body through the heat exchanger, wherein the liquid side and the blood side are separate from one another; wherein the temperature control liquid includes a disinfectant to inhibit microbial growth in the temperature control system; wherein the disinfectant sensor is configured to measure a concentration of the disinfectant in the temperature control liquid during the extracorporeal circulation..Iaddend.

.Iadd.29. The system of claim 28, wherein the disinfectant sensor is situated in the temperature control device..Iaddend.

.Iadd.30. The system of claim 28, wherein the disinfectant sensor provides an electric signal in accordance with the concentration of the disinfectant..Iaddend.

.Iadd.31. The system of claim 28, wherein the heat exchanger comprises a blood side circulating blood and a liquid side circulating the temperature control liquid separate from each other and configured to exchange only heat..Iaddend.

.Iadd.32. The system of claim 28, wherein the disinfectant is one or more of the group including hydrogen peroxide, sodium hypochlorite and citric acid..Iaddend.

.Iadd.33. The system of claim 32, wherein the temperature control liquid includes the disinfectant and water..Iaddend.

.Iadd.34. The system of claim 32, wherein the temperature control liquid includes the disinfectant in a concentration of from 200 to 300 mg/I..Iaddend.

.Iadd.35. The system of claim 28, further comprising a computer for generating a disinfection status of the disinfectant from the measured concentration to be one of sufficiently disinfected, minor contamination, and change temperature control liquid..Iaddend.

.Iadd.36. The system of claim 35, further comprising a display controlled by the computer to indicate the disinfection status and generate an adjustment recommendation in response to the disinfection status..Iaddend.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a schematic diagram illustrating a temperature control device in a heat exchanging system according to a preferred embodiment.

(2) FIG. 2 shows a diagram illustrating a preferred method for controlling the disinfection status of a temperature control device.

DETAILED DESCRIPTION

(3) FIG. 1 shows a schematic diagram of a heat exchanger 10 for human body temperature control during extracorporeal circulation. The heat exchanger 10 comprises a blood side 12 and a temperature control liquid side 14 in which blood and a temperature control liquid are respectively circulated.

(4) The temperature of the temperature control liquid used in the heat exchanger 10 is controlled by a heater and/or cooler 24, i.e. a temperature control device. The heater and/or cooler 24 is a device which is capable of heating or cooling or heating and cooling the temperature control liquid. Preferably, the heater or cooler is capable of both heating and cooling the temperature control liquid so that a defined temperature of the temperature control liquid can be maintained. The heater and/or cooler 24 is part of a temperature control liquid side circuit 26 in which the temperature control liquid is circulated for operating the heat exchanger 10 in controlling the temperature of the human body of a patient.

(5) The heater and/or cooler 24 is provided with a disinfectant sensor 16 configured for measuring a concentration of a disinfectant in the temperature control liquid in the heater and/or cooler 24. The result of the measurement of the sensor 16 is transmitted to a computer 18 which controls a first display 20 indicating the measured concentration of disinfectant in the temperature control liquid and a second display 22 indicating the consequence of the measured concentration. In particular, the second display 22 indicates whether the disinfection status of the temperature control liquid is satisfactory, whether further disinfectant is to be added or whether the temperature control liquid is to be exchanged.

(6) FIG. 2 shows a diagram illustrating a preferred method. In a first step S1, disinfectant is added to the temperature control liquid in the heater and/or cooler. An example for the disinfectant is hydrogen peroxide. As a second step S2, the concentration C of the disinfectant is measured, for example by a specific sensor for the respective disinfectant.

(7) The measuring of the disinfectant concentration C may result in C being at least 200 mg/l. This result means that the concentration C is within an acceptable range and the disinfectant concentration C is further continuously measured.

(8) Another result from the measurement of the disinfectant concentration can be that C is between 100 and 200 mg/l. In this case, the disinfectant concentration C is below the acceptable level but still within a range of minor contamination so that further disinfectant is provided to the temperature control liquid in step S1. The disinfectant concentration C is further continuously measured and the disinfectant is added to the temperature control liquid until the disinfectant concentration is at least 200 mg/l, preferable between 200 and 300 mg/l.

(9) A third measurement result of step S2 can be that the concentration C is below 100 mg/l. In this situation, the temperature control liquid is changed in step S3 and the heater and/or cooler is thoroughly disinfected using disinfectant of a concentration of at least 1000 mg/l or using another disinfectant such as a sodium hypochlorite solution.