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.

The invention claimed is: 
     
       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. 
     
     
       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.   
     
     
       23. The method of claim 22, wherein the disinfectant is one or more of the group including hydrogen peroxide, sodium hypochlorite and citric acid. 
     
     
       24. The method of claim 22, wherein the temperature control liquid includes the disinfectant and water. 
     
     
       25. The method of claim 22, wherein the temperature control liquid includes the disinfectant in a concentration of from 200 to 300 mg/I. 
     
     
       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.   
     
     
       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. 
     
     
       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.   
     
     
       29. The system of claim 28, wherein the disinfectant sensor is situated in the temperature control device. 
     
     
       30. The system of claim 28, wherein the disinfectant sensor provides an electric signal in accordance with the concentration of the disinfectant. 
     
     
       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. 
     
     
       32. The system of claim 28, wherein the disinfectant is one or more of the group including hydrogen peroxide, sodium hypochlorite and citric acid. 
     
     
       33. The system of claim 32, wherein the temperature control liquid includes the disinfectant and water. 
     
     
       34. The system of claim 32, wherein the temperature control liquid includes the disinfectant in a concentration of from 200 to 300 mg/I. 
     
     
       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. 
     
     
       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.