Method for disinfecting a medical device, and medical device

Abstract

The disclosure relates to a method for disinfecting a medical device (2; 102), in which a temperature- and time-dependent first lethality of microbes potentially present in at least one temperature measurement section is calculated on the basis of a temperature (T7; T1, T3, T6.2) measured in the at least one temperature measurement section, at least one temperature- and time-dependent second lethality of microbes potentially present in at least one predetermined volume is calculated on the basis of a temperature (T2, T3, T4, T5, T6, T8, T9, T10; T2, T4, T5, T6.1-T10.1, T7.2-T10.2) assigned to the at least one predetermined volume, and a disinfection is terminated when the first lethality reaches or exceeds a first threshold value and / or the at least one second lethality reaches or exceeds a second threshold value and / or an average, calculated by the control device (8; 108), of the first and the at least one second lethality reaches or exceeds a predetermined third threshold value established by the control device (8; 108). The disclosure also relates to a corresponding medical device (2; 102).

Description

[0001] Method for disinfecting a medical device and medical device

[0002] Description

[0003] Technical area

[0004] The present disclosure relates to a method for disinfecting a medical device, preferably a dialysis machine, in which a disinfectant fluid is heated, introduced into a fluid line system of the medical device, and discharged from the fluid line system, wherein at least one temperature is measured in at least one temperature-measuring section within the fluid line system, based on which temperature- and time-dependent lethality of germs potentially present in the at least one temperature-measuring section is calculated, and it is determined when the lethality reaches or exceeds a threshold value. The disclosure further relates to a medical device configured to carry out a method according to the disclosure.

[0005] State of the art

[0006] A generic method is disclosed, for example, in WO 2022 / 008889 A1. A dialysis machine according to this document comprises a main body, a water purification system separate from the main body, and a liquid disinfection device arranged in the main body. A heating element and a temperature sensor are provided in the liquid disinfection device. The dialysis machine is disinfected by heating a volume of liquid by the heating element until a threshold value is exceeded, and the volume of heated liquid is passed through a first liquid circuit comprising the main body and the liquid disinfection device, and through a second liquid circuit comprising the water purification system. During disinfection, the temperature of the heated liquid is monitored by the temperature sensor and maintained above the threshold value by the heating element.In order to determine the completion of disinfection, lethality values ​​for germs potentially present in the fluid circuits are calculated for the first and second fluid circuits based on the measured temperature.

[0007] The problem with conventional disinfection methods is that the calculation of lethality values ​​is inaccurate, so that the duration of disinfection must be set longer than necessary to meet the required minimum safety level.

[0008] Summary of Revelation

[0009] The object of the present disclosure is therefore to provide a method or a medical device which enables a time-efficient implementation of a disinfection of the medical device.

[0010] This object is achieved with regard to the method by features of claim 1 and with regard to the device by features of claim 8. Advantageous further developments are the subject of the dependent claims.

[0011] A method for disinfecting a medical device according to the disclosure is particularly suitable for disinfecting a blood treatment device, preferably a dialysis machine, and comprises the following steps:

[0012] - Heating a disinfectant fluid,

[0013] - Introducing the disinfectant fluid into a fluid line system of the medical device,

[0014] - Draining the disinfectant fluid from the fluid line system,

[0015] - measuring at least one temperature in at least one temperature measuring section within the fluid line system, - calculating a temperature- and time-dependent first lethality of germs potentially present in the at least one temperature measuring section based on the temperature measured in the at least one temperature measuring section,

[0016] - Establish a first threshold for first lethality and

[0017] - Determine when the first lethality reaches or exceeds the first threshold.

[0018] The disinfectant fluid can in particular be water with added citric or hydroxyacetic acid.

[0019] The fluid line system can in particular comprise at least parts of a dialysis fluid circuit, a blood circuit and / or a water purification circuit or consist of at least one of these circuits.

[0020] The disclosed method further comprises the following steps:

[0021] - Calculating a location-dependent temperature profile for the fluid line system, by means of which a calculated temperature can be assigned to at least one predetermined volume within the fluid line system,

[0022] - Calculating at least one temperature- and time-dependent second lethality of germs potentially present in the at least one predetermined volume based on the temperature assigned to the at least one predetermined volume,

[0023] - setting a second threshold for at least one second lethality,

[0024] - Determine if the at least one second lethality reaches or exceeds the second threshold, and

[0025] - Terminating a disinfection when the first lethality reaches or exceeds the first threshold value and / or the at least one second lethality reaches or exceeds the second threshold value and / or an average value of the first and the at least one second lethality calculated by the control device (8) reaches or exceeds a third threshold value determined by the control device (8).

[0026] The location-dependent temperature profile can be calculated, in particular, by extrapolation based on the measured temperature. In particular, temperatures can be measured at multiple locations in the fluid line system, and a temperature profile for the fluid system can be calculated by interpolation and / or extrapolation based on the multiple measured temperatures. The temperature profile can, in particular, be location- and time-dependent.

[0027] In particular, the second lethality may be calculated on the basis of the same calculation method or the same parameter as was used to calculate the first lethality.

[0028] The temperature can be measured in particular at an inlet, an outlet, a heating element and / or a heat exchanger of the fluid line system.

[0029] The threshold for the first lethality may, in particular, differ from the threshold for the second lethality. Preferably, the threshold for the first lethality may be higher than the threshold for the second lethality, so that higher requirements are placed on the first lethality than on the second lethality. The third threshold may, in particular, be determined with regard to preferably motile germs.

[0030] The threshold values ​​can be set, in particular, depending on a histone of the device. For example, if the device was used to treat a person with chronic hepatitis, higher threshold values ​​can be set for the (first and / or second and / or average) lethality. If a temperature profile is used for disinfection, it is advantageously possible to calculate more precise lethality values ​​at points in the fluid line system where temperature measurement is not possible or only possible under difficult conditions.

[0031] According to one aspect of the disclosure, at least one predetermined volume may be defined, which corresponds to a temperature sensor-free section that is stationary with respect to the fluid line system.

[0032] If the at least one predetermined volume is stationary relative to the fluid line system, disinfection can advantageously be monitored with regard to locally growing microorganisms at locations where no temperature sensor is arranged.

[0033] According to one aspect of the disclosure, at least one predetermined volume can be defined which is movable with respect to the fluid conduit system.

[0034] If at least one predetermined volume is provided that is movable relative to the fluid line system, disinfection can advantageously be monitored with regard to microorganisms that are movable or circulating in the fluid line system.

[0035] According to one aspect of the disclosure, time-dependent changes in the temperature measured in the temperature-measuring section can be taken into account when calculating the first lethality. If temperatures are measured at multiple locations (of one temperature-measuring section or multiple temperature-measuring sections), time-dependent changes in the multiple measured temperatures can be taken into account when calculating the first lethality. In other words, when calculating the first lethality for a specific time interval, temperature changes within the specific time interval can be taken into account. According to one aspect of the disclosure, time-dependent changes in the temperature measured in the temperature-measuring section can be taken into account when calculating the location-dependent temperature profile, so that the temperature profile on which the calculation of the at least one second lethality is based is location- and time-dependent.If temperatures are measured at multiple locations (a temperature measurement section or multiple temperature measurement sections), time-dependent changes in the multiple measured temperatures can be taken into account when calculating the location-dependent temperature profile. In other words, when calculating the location-dependent temperature profile for a specific time interval, temperature changes within the specific time interval can be taken into account.

[0036] If changes in the measured temperature(s) are taken into account when calculating the first lethality and / or the location-dependent temperature profile, the time resolution of disinfection monitoring can be improved.

[0037] According to one aspect of the disclosure, the AO value according to ISO 15883 may be used to calculate the (first and / or second and / or average) lethality.

[0038] If the AO value according to ISO 15883 is used, the monitoring of the disinfection of the fluid line system can advantageously draw on knowledge gained from the disinfection of surgical instruments.

[0039] According to one aspect of the disclosure, a linear progression can be specified for the temperature profile, at least in sections. Preferably, the entire temperature profile can have a linear progression.

[0040] If a linear progression is specified, the monitoring of the

[0041] Disinfection can be simplified. A medical device according to the disclosure is particularly suitable for treating blood and is preferably designed as a dialysis machine. The medical device has a fluid line system, a disinfection device, and a control device. The disinfection device is designed to be able to heat a disinfectant fluid for disinfecting the fluid line system, to introduce it into the fluid line system, and to discharge it from the fluid system. The fluid line system has at least one temperature measuring section with a temperature sensor that is designed to measure a temperature in the temperature measuring section. The control device is designed to be able to carry out a method according to the disclosure.

[0042] According to one aspect of the disclosure, the medical device may have a graphical user interface configured to allow selection of different boundary conditions and / or configurations of the medical device, and the control device may be configured to adapt the course of the temperature profile depending on a selection of at least one boundary condition and / or configuration.

[0043] The user interface can be designed, in particular, such that a specific air temperature or a specific air temperature range, a specific air pressure or a specific air pressure range, and / or a specific air humidity or a specific air humidity range of the environment of the medical device can be entered or selected as boundary conditions. Alternatively or additionally, the user interface can be designed, in particular, such that states of the medical device in which different components are installed on the device can be selected as configurations of the medical device.For example, the user interface can be designed such that a configuration of a dialysis machine can be selected in which a set for a first therapy, for example, hemodialysis, is installed on the dialysis machine, and otherwise a configuration of the dialysis machine can be selected in which a set for a second therapy, for example, hemodiafiltration, is installed on the dialysis machine. For different configurations of the device or for different therapies of the dialysis machine, corresponding temperature profiles can be stored in a database of the device or the control device. The user interface can, in particular, be a touch-sensitive screen.

[0044] If the device is designed in such a way that the temperature profile can be adapted to different boundary conditions and / or configurations by means of a user interface, the monitoring of disinfection can be improved.

[0045] According to one aspect of the disclosure, the medical device can have at least one heating device controllable by the control device, preferably in the disinfection device, and the control device can be designed to adapt the course of the temperature profile depending on the operation of the heating device. In other words, the control device can be designed such that it adapts the course of the temperature profile based on commands to the heating device. The adaptation carried out using the commands can then be checked based on the subsequently measured temperature. In particular, a database can be stored in the device or the control device, in which database corresponding temperature profiles are stored for different commands to the heating device.

[0046] Brief description of the drawings

[0047] The present invention will be described in more detail below using preferred embodiments with reference to the accompanying drawings. Figure 1 shows a schematic view of a medical device in the form of a dialysis machine according to a first embodiment in a state in which dialysis can be performed;

[0048] Fig. 2 is a schematic view of the dialysis machine shown in Fig. 1 in a state in which disinfection can be carried out;

[0049] Fig. 3 is a schematic detailed view of a line section marked in Fig. 2; and

[0050] Fig. 4 is a diagram of a temperature profile along the line section shown in Fig. 3.

[0051] Fig. 5 is a schematic view of a medical device in the form of a dialysis machine according to a second embodiment in a state in which dialysis can be performed;

[0052] Fig. 6 is a schematic view of the dialysis machine shown in Fig. 5 in a state in which disinfection of a dialysis fluid circuit can be carried out;

[0053] Fig. 7 is a schematic view of the dialysis machine shown in Fig. 5 in a state in which disinfection of the blood circuit can be carried out;

[0054] Fig. 8 is a view corresponding to Fig. 6 with a marked line section of the dialysis fluid circuit;

[0055] Fig. 9 shows a view corresponding to Fig. 7 with marked line sections in the dialysis fluid circuit and the blood circuit; and Fig. 10 shows a diagram with a temperature profile along the line section marked in Fig. 8 and with a temperature profile along the line sections marked in Fig. 9 in the dialysis machine according to the second embodiment.

[0056] Detailed description of preferred embodiments

[0057] Fig. 1 shows a medical device 2 in the form of a dialysis machine, which has a fluid line system 4 in the form of a blood circuit, a disinfection device 6 and a control device 8.

[0058] The fluid line system 4 or the blood circuit has a fluid inlet 10 into which fluid or blood can be introduced during a therapy.

[0059] Downstream of the fluid inlet 10, a first bubble chamber 12 is arranged in the fluid line system 4, which is provided with a first pressure sensor 14 in order to be able to measure a pressure of a fluid located in the first bubble chamber 12.

[0060] Downstream of the first bubble chamber 12, a fluid pump 16 is arranged in the fluid line system 4 in order to be able to convey fluid in the fluid line system 4.

[0061] Downstream of the fluid pump 16, a fluid supply line 18 is arranged in the fluid line system 4. During therapy, an anticoagulant such as heparin can be added to the pumped fluid or blood via the fluid supply line 18.

[0062] Downstream of the fluid supply line 18, a second bubble chamber 20 is arranged in the fluid line system 4 and is provided with a second pressure sensor 22 in order to be able to measure the pressure of a fluid located in the second bubble chamber 20. Downstream of the second bubble chamber 20, a fluid filter 24 is arranged in the fluid line system 4. The fluid filter 24 has a fluid inlet 26, a fluid outlet 28, a dialysis fluid inlet 30, and a dialysate outlet 32. The fluid inlet 26 and the fluid outlet 28 are connected to a fluid chamber (not shown). The dialysis fluid inlet 30 and the dialysate outlet 32 ​​are connected to a dialysis fluid chamber (not shown). The fluid chamber and the dialysis fluid chamber are connected to one another via a semipermeable membrane (not shown). During therapy, pressure can be applied to the fluid orComponents such as toxins are removed from the blood via the semipermeable membrane by diffusion and / or convection. The removed components enter a dialysis fluid, which is conveyed from a dialysis fluid container 34 by means of a dialysis fluid pump 36 via the dialysis fluid inlet 30 into the dialysis fluid chamber, mixes in the dialysis fluid chamber with the components removed from the fluid or blood, and is conveyed together with the components removed from the fluid or blood as dialysate from the dialysate outlet 32 ​​by means of a dialysate pump 38 into the dialysate container 40.

[0063] Downstream of the fluid outlet 28 of the fluid filter 24, a temperature sensor 42 is arranged in the fluid line system 4, by means of which a temperature of the fluid conveyed in the fluid line system 4 can be measured.

[0064] Downstream of the temperature sensor 42, a third bubble chamber 44 is arranged in the fluid line system 4, which is provided with a third pressure sensor 46 in order to be able to measure a pressure of a fluid located in the third bubble chamber 44.

[0065] Downstream of the third bubble chamber 44, an air detector 48 is arranged in the fluid line system 4, by means of which air can be detected in the fluid conveyed in the fluid line system 4. Downstream of the air detector 48, a fluid outlet 50 of the fluid line system 4 is arranged, from which fluid or blood treated during therapy can be discharged from the fluid line system 4.

[0066] The disinfection device 6 has a tank 52 connected to an inlet line 54, via which a disinfectant fluid can be introduced into the tank 52 by means of an inlet pump 56 arranged in or on the inlet line 54. The tank 52 is further connected to an outlet line 58, via which a disinfectant fluid can be discharged from the tank 52 by means of an outlet pump 60 arranged in or on the outlet line 58. Downstream of the outlet pump 60, a temperature sensor 62 is further arranged in or on the outlet line 58. A heating device 64 is provided in or on the tank 52, by means of which the disinfectant fluid in the tank 52 can be heated or warmed.

[0067] During a therapy, the inlet line 54 and the outlet line 58 of the disinfection device 6 are not connected to the fluid line system 4.

[0068] Fig. 2 shows the device according to the disclosure in a state in which the fluid line system 4 can be disinfected by means of the disinfection device 6.

[0069] In order to be able to disinfect the fluid line system 4 prior to therapy, the outlet line 58 of the disinfection device 6 is connected to the fluid inlet 10 of the fluid line system 4 by means of a first flushing bridge 66, the inlet line 54 of the disinfection device 6 is connected to the fluid outlet 50 of the fluid line system 4 by means of a second flushing bridge 68, and the dialysis fluid inlet 30 of the fluid filter 24 is connected to the dialysate outlet 32 ​​of the fluid filter 24 by means of a third flushing bridge 70. The flushing bridges 66, 68, and 70 can be implemented as separate hoses or lines or line sections that can be manually attached to the corresponding connections of the fluid line system 4 or the disinfection device 6. Alternatively or additionally, the device can have multi-way valves at the connections 10, 30, 32, and 50 of the fluid line system 4.

[0070] The multi-way valves at the connections 10 and 50 can be designed such that, on the one hand, in a therapy position, they connect the fluid inlet 10 of the fluid line system 4 with a blood outlet of a person to be treated and the fluid outlet 50 of the fluid line system 4 with a blood inlet of the person to be treated, and, on the other hand, in a disinfection position, they connect the fluid inlet 10 of the fluid line system 4 with the outlet line 58 of the disinfection device 6 and the fluid outlet 50 of the fluid line system 4 with the inlet line 54 of the disinfection device 6.

[0071] The multi-way valves at the connections 30 and 32 can be designed such that, on the one hand, in a therapy position, they connect the dialysis fluid inlet 30 of the fluid filter 24 to the dialysis fluid container 24 and the dialysate outlet 32 ​​of the fluid filter 24 to the dialysate container 40, and, on the other hand, in a disinfection position, they connect the dialysis fluid inlet 30 of the fluid filter 24 to the dialysate outlet 32 ​​of the fluid filter 24.

[0072] If multi-way valves are provided, switching of the device from a therapy state, in which therapy or dialysis can be carried out, to a disinfection state, in which disinfection can be carried out, can be designed in such a way that no manual conversion is necessary.

[0073] During disinfection, disinfectant fluid in tank 52 is heated by heating device 64 and pumped into fluid line system 4 by outlet pump 60 via flushing bridge 66. In fluid line system 4, the heated disinfectant fluid flows through first bubble chamber 12 before being pumped into fluid filter 24 via second bubble chamber 20 by fluid pump 16. Flushing bridge 70 ensures that the disinfectant fluid leaves fluid filter 24 only via fluid outlet 28. From fluid outlet 28, the disinfectant fluid flows back into tank 52 via temperature sensor 42, third bubble chamber 44, and flushing bridge 68, with inlet pump 56 pumping the disinfectant fluid into tank 52. The heat introduced into fluid line system 4 by the disinfectant fluid kills any germs potentially present in fluid line system 4.

[0074] In order to be able to evaluate the disinfection of the device 2 according to the disclosure, the lethality of germs potentially present in a relevant line section of the device 2 is calculated using the AO value concept according to ISO 15883.

[0075] Fig.3 shows a schematic detailed view of the line section marked with dots in Fig. 2, which extends in the disinfection state of the device 2 from the temperature sensor 62 of the disinfection device 6 to the fluid outlet 50 of the fluid line system 4.

[0076] The A0 value is a measure of lethality and is calculated according to ISO 15883 using the following formula:

[0077] "z" is the z-value, which can be defined, for example, in ISO 11139. For the A0 value, "z = 10°C" applies.

[0078] "T(t)" is the temperature of the disinfectant fluid in °C as a function of time "t." "At" is the selected time interval in seconds.

[0079] To enable time-efficient disinfection, the AO value of the entire line section is not calculated based solely on the two temperatures measured by temperature sensors 42 and 62. Rather, according to the disclosure, the line section or the fluid line system 4 or the relevant part of the fluid line system 4 is first divided into k subsections. For example, the line section is divided into k=10 subsections, as shown in Fig. 4.

[0080] Those subsections of the line section or fluid line system 4 that extend past temperature sensors 42 and 62 are temperature measuring sections according to the disclosure. To calculate the A0 values ​​of the temperature measuring sections, the temperature T7 measured by temperature sensor 42 and the temperature T1 measured by temperature sensor 62 can be used directly. The A0 values ​​of the temperature measuring sections each correspond to a first lethality according to the disclosure.

[0081] In order to calculate AO values ​​in the line section away from temperature sensors 62 and 42, a temperature profile is calculated based on the measured temperatures T1 and T7. For example, as shown in Fig. 4, a linear temperature profile is assumed. Depending on a position x in the line section and time t, the temperature can be calculated using the following formula:

[0082] Based on the temperatures T2 to T6 and T8 to T10 calculated using this formula, corresponding AO values ​​can be calculated for the sections away from the temperature measurement sections. These AO values ​​away from the temperature measurement sections specified by temperature sensors 42 and 62 each correspond to a second lethality according to the disclosure. The volumes in the sections away from the temperature measurement sections correspond to predetermined volumes according to the disclosure.

[0083] To obtain an AO value for the entire line section shown in Fig. 3, an averaged AO value can be calculated from the calculated temperature profile using the following formula:

[0084] For the example shown in Fig. 4, “k = 10” applies.

[0085] The AO values ​​for the temperature measuring sections, the sections of the line section shown in Fig. 3 away from the temperature measuring sections and the averaged AO value are calculated by the control device 8, which is signal-connected to the actuators (fluid pump 16, dialysis fluid pump 36, dialysate pump 38, inlet pump 56, outlet pump 60 and heating device 64) and the sensors (pressure sensors 14, 22 and 46, temperature sensors 42 and 62 and air detector 48) of the device 2.

[0086] In order to be able to set threshold values ​​for the AO values, the device 2 has a touch-sensitive screen 72 which is signal-connected to the control device 8.

[0087] At least one threshold value for the AO values ​​of the temperature measuring sections, at least one threshold value for the subsections outside the temperature measuring sections, and at least one threshold value for the averaged AO value of the line section can be entered on the screen 72. Depending on the input on the screen 72, the control unit 8 sets the corresponding threshold values. During disinfection, the control unit 8 continuously compares the calculated AO values ​​for the temperature measuring sections and for the subsections outside the temperature measuring sections, as well as the calculated averaged AO value, with the corresponding previously defined threshold values.As soon as the calculated AO values ​​for the temperature measuring sections and for the subsections away from the temperature measuring sections as well as the calculated average A0 value reach or exceed the corresponding threshold values, the control device 8 terminates the disinfection by stopping the pumps 60, 16 and 56.

[0088] Fig. 5 shows a medical device 102 in the form of a dialysis machine, which has a fluid line system 104 in the form of a blood circuit, a fluid line system 105 in the form of a dialysis fluid circuit, a disinfection device 106 and a control device 108, as used during a therapy.

[0089] The fluid line system 104 or the blood circuit can be part of the dialysis machine or a reusable and separately mountable set consisting of blood tubing and dialyzer.

[0090] The fluid line system 104 or the blood circuit has a fluid inlet 110 into which fluid or blood can be introduced during a therapy.

[0091] Downstream of the fluid inlet 110, various functional components are arranged in the fluid line system 104, which are not of primary importance for this disclosure. These are summarized as components 111.

[0092] Downstream of 111 is a pump 116, which pumps the fluid in the fluid line system 104. Downstream of the pump 116, a fluid filter 124 is arranged in the fluid line system 104. The fluid filter 124 has four connections for fluid. Two are responsible for the inlet (126) and outlet (128) of the blood circuit and two for the inlet (130) and outlet (132) of the dialysis fluid circuit. The circuits for blood and dialysis fluid are connected to each other via a semipermeable membrane (not shown). During therapy, components such as toxins can be removed from the fluid or blood via the semipermeable membrane by diffusion and / or convection. The removed components pass from the blood circuit into the dialysis fluid.

[0093] Downstream of the fluid outlet 128 of the fluid filter 124, a temperature sensor 142 is arranged in the fluid line system 104, by means of which a temperature of the fluid conveyed in the fluid line system 104 can be measured.

[0094] Downstream of the temperature sensor 142, various functional components are arranged in the fluid line system 104, which are not of primary importance for the present disclosure. These are summarized as components 143.

[0095] Downstream of the components 143, a fluid outlet 150 of the fluid line system 104 is arranged, from which fluid or blood treated during a therapy can be discharged from the fluid line system 104.

[0096] The fluid line system 105 or the dialysis fluid circuit has a fluid inlet 174 into which water can be introduced.

[0097] Downstream of the fluid inlet 174, a fluid tank 152 is arranged, in which fluid, or dialysis fluid in therapy, is collected. A pump 176 can withdraw fluid from the fluid tank 152 and convey it in a heating circuit to a heater 178. The heater 178 is used to heat the fluid and transports it back to the fluid tank 152 via a line 180.

[0098] The line 180, which can be designed, for example, as a hose element W6, contains a temperature sensor 182 which determines the temperature of the liquid in the dialysis fluid circuit 105 after initial heating.

[0099] A pump 184 can withdraw fluid from the fluid tank 152 and pump it toward the bloodstream 104. Various functional components of the dialysis fluid circuit are arranged downstream of the pump 184. These components, with the exception of a temperature sensor 188, are not of primary importance for the present disclosure. These components are summarized by 186 and 190. The temperature sensor 188 is used to determine the temperature of the fluid being pumped toward the bloodstream 104.

[0100] Downstream of the components 190, the fluid is conveyed to the fluid filter 124 via a line 192, which may be configured as a hose. The line 192 may be connected to the fluid connection 130 on the fluid filter 124 via a coupling.

[0101] Downstream of the fluid filter 124, the liquid can be directed away from the fluid filter 124 via a line 196, which can be configured as a hose. The line 194 can be connected to the fluid filter 124 via a coupling.

[0102] Downstream of line 194, the fluid is passed through various components that are not of primary importance for the present disclosure. These components are summarized as 196. Downstream of components 196, a pump 198 is arranged, which pumps the fluid back into the fluid tank 152. The fluid tank 152 is designed such that the discharged fluid does not need to come into contact with the incoming fluid.

[0103] A valve 200 is arranged downstream of the pump 198. During therapy operation, the valve 200 directs the fluid toward an outlet 202.

[0104] The disinfection device 106 has an inlet 204 through which disinfectant can be introduced. The disinfection device 106 is not necessarily connected during therapy operation.

[0105] Fig. 6 shows the medical device 102 during disinfection of the dialysis fluid circuit 105.

[0106] For disinfection, a distinction must be made between different phases.

[0107] The first phase of disinfection involves the introduction of the disinfectant.

[0108] For disinfection, a disinfectant is introduced via inlet 204. For this purpose, lines 192 and 194 are connected to the disinfection device 106 with their couplings. A three-way valve 206 of the disinfection device 106 can be operated in various configurations. During the introduction of the disinfectant, it connects the inlet 204 to line 194. The pump 198 can thus introduce the disinfectant into the circuit 105. Downstream of the pump 198, the valve 200 is set so that the disinfectant reaches the fluid tank 152. There it is mixed with water from the fluid inlet 174. This mixture is referred to below as the disinfectant liquid. In the second phase of disinfection, the disinfectant liquid is heated. For this purpose, the liquid is pumped from the fluid tank 152 by the pump 176 via a heating element of the heater 178.The temperature of the disinfectant liquid is continuously determined via the temperature sensor 182.

[0109] The liquid can be circulated continuously and repeatedly over the heating element of the heater 178 in order to reach the required temperature.

[0110] In the third phase of disinfection, the heated disinfectant fluid is circulated in the dialysis fluid circuit 105. This is where the actual disinfection of the dialysis fluid circuit 105 takes place.

[0111] For this purpose, the same actuators as in the therapy phase can be used to distribute the fluid in the dialysis fluid circuit 105. The pump 184 pumps the disinfectant fluid from the fluid tank 152 via the component(s) 186, the temperature sensor 188, and the component(s) 190. The temperature sensor 188 allows the temperature of the disinfectant fluid to be measured. This measured value is used to extrapolate the temperature in other areas of the dialysis fluid circuit 105.

[0112] Downstream of component(s) 190, the fluid is passed to the disinfection device 106. During this phase, the three-way valve 206 is set to direct the fluid further into line 194. The fluid is returned to the fluid tank 152 via component(s) 196, pump 198, and valve 200.

[0113] The temperature of the disinfectant fluid continuously decreases along the flow path, so that the disinfectant effect is increasingly reduced. The heating circuit with elements 176 to 182 remains active during this phase to maintain the temperature in the fluid tank 152. During this phase, the disinfectant fluid can be circulated through the fluid system until the desired lethality values ​​are achieved at each location.

[0114] Fig. 7 shows the medical device 102 during disinfection of the bloodstream 104.

[0115] In the (optional) fourth phase of disinfection, the blood circuit 104 can be disinfected in addition to the dialysis fluid side. The circulation of the disinfectant fluid from phase 3 of disinfection continues. However, during this phase, the couplings of lines 192 and 194 are reconnected to the fluid filter 124.

[0116] This flushes the fluid filter 124 with the heated disinfectant fluid. The disinfectant can also penetrate the bloodstream 104 through the semipermeable membrane.

[0117] In this phase, the fluid inlet 110 and the fluid outlet 150 of the blood circuit 104 are connected to each other by means of a coupling 208.

[0118] During this phase, the pump 116 is used to circulate the fluid in the bloodstream 104. The temperature in the bloodstream 104 is continuously increased through the exchange of matter and heat in the fluid filter 124. The temperature sensor 142 measures the temperature in the bloodstream 104 and can be used to extrapolate the temperature in other areas of the bloodstream 104.

[0119] In order to evaluate disinfection of the disclosed device 102, the lethality of germs potentially present in a relevant line section of the device 102 is calculated using the AO value concept according to ISO 15883. Fig. 8 shows a view corresponding to Fig. 6 with a marked line section of the dialysis fluid circuit 105 during disinfection of the dialysis fluid circuit 105. Fig. 9 shows a view corresponding to Fig. 7 with marked line sections in the dialysis fluid circuit 105 and the blood circuit 104 during additional disinfection of the blood circuit 104.

[0120] Fig. 10 shows a schematic detailed view of the temperature profile in the line sections of the dialysis fluid circuit 105 and the blood circuit 104 marked in Figures 8 and 9. The temperature profile of the line section in the dialysis fluid circuit 105 is shown with a solid line, and the temperature profile of the line section in the blood circuit 104 is shown with a dashed line. The highest temperature is reached in the heating element of the heater 178 and continues to decrease from there along the fluid path x. The temperature at the positions of the temperature sensors 182 and 188 is known by measurement. Using these measured values, the temperature in other areas of the dialysis fluid circuit 105 can be extrapolated.

[0121] The temperature profile in the blood circuit 104 results from the temperature profile in the dialysis fluid circuit. In the area of ​​the fluid filter 124, the temperatures in the dialysis fluid circuit 105 and in the blood circuit 104 are almost identical, since the fluid filter 124 is a very effective heat exchanger due to its semipermeable membrane. In the blood circuit 104, the temperature is also known for the position or section of the temperature sensor 142. The temperature in the remaining areas of the blood circuit 104 can be extrapolated from these two points (i.e., fluid filter 124 and temperature sensor 142).

[0122] As in the first embodiment, the AO value is used as a measure of lethality and is calculated according to ISO 15883 using the following formula:

[0123] "z" is the z-value, which can be defined, for example, in ISO 11139. For the AO value, "z = 10°C" applies.

[0124] “T(t)” is the temperature of the disinfectant fluid in °C as a function of time “t”.

[0125] “At” is the selected time interval in seconds.

[0126] To enable time-efficient disinfection, the AO value of the entire line section is not calculated based solely on the temperatures T1, T3, and T6.2 measured by the temperature sensors 182, 188, and 142. Rather, according to the disclosure, the line section of the dialysis fluid circuit 105 to be disinfected (see Fig. 8 and the solid line in Fig. 10) is first divided into k subsections. For example, the line section is divided into k=10 subsections, as shown in Fig. 10. If the blood circuit is disinfected, the line section of the dialysis fluid circuit 105 and then the line section of the blood circuit 104 are considered together, starting from the temperature sensor 182 to the fluid filter 124, and are then divided into k subsections (see Fig. 9 and in Fig. 10 the solid line up to x(124) and the dashed line from x(124)).

[0127] Those subsections of the line section or fluid line systems 104 and 105 that extend past the temperature sensors 142, 182, and 188 are temperature measuring sections according to the disclosure. To calculate the A0 values ​​of the temperature measuring sections, the temperatures measured by the temperature sensors 142, 182, and 188 (e.g., T1=T(182), T3=T(188), and T6.2=T(142)) can be used directly. The A0 values ​​of the temperature measuring sections each correspond to a first lethality according to the disclosure. In order to be able to calculate AO values ​​in the line section away from the temperature sensors 142, 182, and 188, a temperature profile for the dialysis fluid circuit 105 and the blood circuit 104 is calculated based on the measured temperatures T1 = T(182), T3 = T(188), and T6.2 = T(142). For example, a linear temperature profile is assumed, as shown in Fig. 10.Depending on a position x in the pipe section and the time t, the temperature can be calculated using the following formula:.

[0128] Based on the temperatures T2, T4, T5, and T6.1 to T10.1, or T2, T4, T5, and T6.2 to T10.2 calculated using this formula, corresponding AO values ​​can be calculated for the sections outside the temperature measurement sections. These AO values ​​outside the temperature measurement sections specified by temperature sensors 142, 182, and 188 each correspond to a second lethality according to the disclosure. The volumes in the sections outside the temperature measurement sections correspond to predetermined volumes according to the disclosure.

[0129] To obtain an AO value for the entire line section shown in Fig. 8 or Fig. 9, an averaged AO value can be calculated from the calculated temperature profile using the following formula:

[0130] For the examples shown in Fig. 10, “k = 10” applies.

[0131] The AO values ​​for the temperature measuring sections, the sections of the line sections shown in Fig. 8 and Fig. 9 away from the temperature measuring sections and the averaged AO value are calculated by the control device 108, which is signal-connected to the actuators (e.g. pumps 176, 184, 198 and 116) and the sensors (e.g. temperature sensors 142, 182 and 188) of the device 102.

[0132] In order to be able to set threshold values ​​for the A0 values, the device 102 has a touch-sensitive screen 172 that is signal-connected to the control device 108.

[0133] At least one threshold value for the A0 values ​​of the temperature measurement sections, at least one threshold value for the subsections outside the temperature measurement sections, and at least one threshold value for the average A0 value of the line section can be entered on screen 172. Depending on the input on screen 172, the control device 108 sets the corresponding threshold values.

[0134] During disinfection, the control unit 108 continuously compares the calculated A0 values ​​for the temperature measurement sections and for the subsections outside the temperature measurement sections, as well as the calculated average AO value, with the corresponding previously defined threshold values. As soon as the calculated A0 values ​​for the temperature measurement sections and for the subsections outside the temperature measurement sections, as well as the calculated average AO value, reach or exceed the corresponding threshold values, the control unit 108 terminates the disinfection by beginning to flush out the disinfectant (e.g., by means of the pumps 176, 184, 198, and 116) and switching off the heater 178. List of Reference Symbols

[0135] 2; 102 device

[0136] 4; 104, 105 fluid line system

[0137] 6; 106 Disinfection facility

[0138] 8; 108 control device

[0139] 10; 110 Fluid inlet of the fluid line system

[0140] 12 first bubble chamber

[0141] 14 first pressure sensor

[0142] 16; 116 Fluid pump

[0143] 18 Fluid supply line

[0144] 20 second bubble chamber

[0145] 22 second pressure sensor

[0146] 24; 124 fluid filters

[0147] 26; 126 fluid inlet of the fluid filter

[0148] 28; 128 fluid outlet of the fluid filter

[0149] 30; 130 Dialysis fluid inlet

[0150] 32; 132 dialysate outlet

[0151] 34 dialysis fluid containers

[0152] 36 Dialysis fluid pump

[0153] 38 Dialysate pump

[0154] 40 dialysate containers

[0155] 42; 124 Temperature sensor in the fluid line system

[0156] 44 third bladder chamber

[0157] 46 third pressure sensor

[0158] 48 Air detector

[0159] 50; 150 Fluid outlet of the fluid line system

[0160] 52; 152 tanks

[0161] 54 Inlet line

[0162] 56 Inlet pump

[0163] 58 Outlet line

[0164] 60 discharge pump

[0165] 62 Temperature sensor in the disinfection device 64 Heating device

[0166] 66 first flushing bridge

[0167] 68 second flushing bridge

[0168] 70 third flushing bridge

[0169] 72; 172 touch-sensitive screen

[0170] 111 Component

[0171] 143 Component

[0172] 174 Fluid inlet

[0173] 176 Pump

[0174] 178 Heating

[0175] 180 line

[0176] 182 Temperature sensor

[0177] 184 Pump

[0178] 186; 190 component

[0179] 188 Temperature sensor

[0180] 192, 194 management

[0181] 196 Component

[0182] 198 Pump

[0183] 200 valve

[0184] 202 Drain

[0185] 204 Entrance

[0186] 206 three-way valve

[0187] 208 Clutch

Claims

Claims 1. A method for disinfecting a medical device (2; 102), in particular a blood treatment device, preferably a dialysis machine, comprising the steps - Heating a disinfectant fluid, - introducing the disinfectant fluid into a fluid line system (4; 104, 105) of the medical device (2; 102), - discharging the disinfectant fluid from the fluid line system (4; 104, 105), - measuring at least one temperature (T7; T1, T3, T6.2) in at least one temperature measuring section within the fluid line system (4; 104, 105), - Calculating a temperature- and time-dependent first lethality of germs potentially present in the at least one temperature measuring section based on the temperature measured in the at least one temperature measuring section (T7; T1, T3, T6.2), - Establish a first threshold for first lethality and - Determine when the first lethality reaches or exceeds the first threshold, characterized by the steps - Calculating a location-dependent temperature profile for the fluid line system (4; 104, 105), by means of which a calculated temperature (T2, T3, T4, T5, T6, T8, T9, T10; T2, T4, T5, T6.1 -T10.1, T7.2-T10.2) can be assigned to at least one predetermined volume within the fluid line system (4; 104, 105), - Calculating at least one temperature- and time-dependent second lethality of germs potentially present in the at least one predetermined volume based on the temperature assigned to the at least one predetermined volume (T2, T3, T4, T5, T6, T8, T9, T10; T2, T4, T5, T6.1 -T10.1, T7.2-T10.2), - setting a second threshold for at least one second lethality, - Determine if the at least one second lethality reaches or exceeds the second threshold, and - Terminate disinfection if the first lethality exceeds the first threshold and / or the at least one second lethality exceeds the second Threshold value and / or an average value of the first and the at least one second lethality calculated by the control device (8; 108) reaches or exceeds a third threshold value determined by the control device (8; 108).

2. Method according to claim 1, wherein at least one predetermined volume is defined which corresponds to a temperature sensor-free section which is stationary with respect to the fluid line system (4; 104, 105).

3. The method according to claim 1 or 2, wherein at least one predetermined volume is defined which is movable with respect to the fluid conduit system.

4. Method according to one of claims 1 to 3, wherein time-dependent changes in the temperature (T7; T1, T3, T6.2) measured in the temperature measuring section are taken into account when calculating the first lethality.

5. Method according to one of claims 1 to 4, wherein, when calculating the location-dependent temperature profile, time-dependent changes in the temperature measured in the temperature measuring section (T7; T1, T3, T6.2) are taken into account, so that the temperature profile on which the calculation of the at least one second lethality is based is location- and time-dependent.

6. Method according to one of claims 1 to 5, wherein the AO value according to ISO 15883 is used to calculate the lethality.

7. Method according to one of claims 1 to 6, wherein a linear course is specified for the temperature profile at least in sections.

8. Medical device (2; 102), in particular for treating blood, preferably designed as a dialysis machine, with a fluid line system (4; 104, 105), a disinfection device (6; 106) which is designed to be able to heat a disinfection fluid for disinfection of the fluid line system (4; 104, 105), to be able to introduce it into the fluid line system (4; 104, 105) and to discharge it from the fluid line system (4; 104, 105), and a control device (8; 108), wherein the fluid line system (4; 104, 105) has at least one temperature measuring section with a temperature sensor (42; 142, 182, 188) which is designed to be able to measure a temperature (T7; T1, T3, T6.2) in the temperature measuring section, and the control device (8; 108) is designed to be able to carry out a method according to one of claims 1 to 7.

9. Medical device (2; 102) according to claim 8, wherein the medical device (2; 102) has a graphical user interface (72; 172) which is designed to allow different boundary conditions and / or configurations of the medical device (2; 102) to be selected, and the control device (8; 108) is designed to be able to adapt the course of the temperature profile depending on a selection of at least one boundary condition and / or configuration.

10. Medical device (2; 102) according to claim 8 or 9, wherein the medical device (2; 102) has at least one heating device (64; 178) controllable by the control device (8; 108) and the control device (8; 108) is designed to be able to adapt the course of the temperature profile depending on an operation of the heating device (64; 178).

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