Device for setting up a dilution measurement site

Abstract

The device according to the invention serves to set up a dilution measurement site on a hemodialyzer. Using such a measurement site, it is possible to determine the filling status of a dialysis patient during dialysis treatment, by means of dilution measurements. Checking the fluid balance by means of weighing the dialysis patient, which is subject to error, can be eliminated. The arterial connection piece is connected with an arterial fistula needle, and the venous connection piece is connected with a venous fistula needle as the blood vessel access. The venous connection piece has an injection channel through which a bolus required to perform a dilution measurement can be injected into the blood, which flows through the venous connection piece coming from the hemodialyzer, in the direction of the venous blood vessel access. The arterial connection piece has a temperature sensor by means of which the temperature of the blood, which flows through the venous connection piece coming from the arterial blood vessel access, in the direction of the hemodialyzer, can be measured. The system response to the disruption caused in the bloodstream of the dialysis patient by means of the bolus injection can be determined by way of this temperature measurement, and the bloodstream filling status can be determined from this.

Description

Elements that correspond to one another in the individual figures are provided with the same reference symbol, to the extent that this makes sense.

FIG. 1 shows a sectional view of a device according to the invention, in which the arterial and the venous connection piece are configured separately and already connected with a fistula needle as the blood vessel access point, in each instance.

FIG. 2 shows a sectional view of a device according to the invention, in which the arterial and the venous connection piece are integrated into a common functional unit.

FIG. 3 shows a system according to the invention, having the device from FIG. 2, shown only in stylized form, a hemodialyzer, and an evaluation unit, whereby the device is connected to the bloodstream of a dialysis patient by way of two fistula needles.

FIG. 4 a shows a device according to the invention similar to FIG. 2, whereby, however, a catheter is provided for the arterial blood vessel connection, and the temperature sensor has been moved into the catheter. The catheter is shown in interrupted and non-sectioned form.

FIG. 4 b-c illustrate two different variants of the temperature sensor arrangement, using a sectional representation of the distal end of the catheter that is enlarged as compared with FIG. 4a.

Claims

1. Device for setting up a dilution measurement site on a hemodialyzer, which has the following: an arterial connection piece, having a hemodialyzer input connector,at least one of a sensor for measuring the temperature of blood to be dialyzed and a sensor for measuring an indicator concentration in blood to be dialyzed, as well asa venous connection piece, having a hemodialyzer output connector and an injection channel for injecting a bolus into dialyzed blood that flows through the venous connection piece.

2. Device according to claim 1, wherein the arterial connection piece has connection means for connecting to an arterial blood vessel access and the venous connection piece has connection means for connecting to a venous blood vessel access.

3. Device according to claim 2, wherein the arterial blood vessel access is connected with the arterial connection piece by way of the connection means of the arterial connection piece, and the venous blood vessel access is connected with the venous connection piece by way of the connection means of the venous connection piece.

4. Device according to claim 2, wherein the venous blood vessel access has a fistula needle.

5. Device according to claim 2, wherein the arterial blood vessel access has a fistula needle.

6. Device according to claim 2, wherein the arterial blood vessel access and the venous blood vessel access are integrated into a shunt.

7. Device according to claim 3, wherein the arterial blood vessel access has a catheter.

8. Device according to claim 7, wherein the catheter functions as a carrier of at least one of the sensor for measuring the temperature of the blood to be dialyzed and the sensor for measuring an indicator concentration in the blood to be dialyzed.

9. Device according to claim 8, wherein at least one of the sensor for measuring the temperature of the blood to be dialyzed and the sensor for measuring an indicator concentration in the blood to be dialyzed is integrated into the catheter.

10. Device according to claim 8, wherein at least one of the sensor for measuring the temperature of the blood to be dialyzed and the sensor for measuring an indicator concentration in the blood to be dialyzed is integrated into a probe that is pushed into the lumen of the catheter.

11. Device according to claim 8, wherein the sensor is designed for measuring at least one of the temperature of blood flowing through the catheter and an indicator concentration in blood flowing through the catheter.

12. Device according to claim 8, wherein the sensor is designed for at least one of measuring the temperature of the free blood flow in the vicinity of the distal catheter end and measuring an indicator concentration in the free blood flow in the vicinity of the distal catheter end.

13. Device according to claim 1, wherein the sensor is designed for measuring at least one of the temperature of blood flowing through the arterial connection piece and an indicator concentration in blood flowing through the arterial connection piece.

14. Device according to claim 1, wherein the arterial connection piece and the venous connection piece are integrated into a common functional unit.

15. Device according to claim 1, wherein the injection channel (16) has a temperature sensor for measuring the temperature in the interior of the injection channel.

16. Device according to claim 1, wherein the injection channel has a pressure switch having switching characteristics that bring about one of switch opening and switch closing once a pressure threshold value has been reached in the injection channel.

17. Device according to claim 1, wherein the injection channel has a flow switch having switching characteristics that bring about one of switch opening and switch closing once a fluid flow threshold value has been reached in the injection channel.

18. Device according to claim 1, wherein the injection channel has a valve.

19. Device according to claim 1, wherein the hemodialyzer output connector of the venous connection piece is equipped with a valve for avoiding a bolus flow in the direction of the hemodialyzer.

20. Device according to claim 1, wherein the arterial connection piece and the venous connection piece are packaged in sterile packaging.

21. Device according to claim 20, wherein the arterial connection piece and the venous connection piece are packaged in a common sterile packaging.

22. Hemodialyzer, having a hemodialyzer input for blood flowing to the hemodialyzer, which input is connected with the hemodialyzer input connector of the arterial connection piece of a device according to claim 1, as well asa hemodialyzer output for blood flowing away from the hemodialyzer, which output is connected with the hemodialyzer output connector of the venous connection piece of said device.

23. System for carrying out dilution measurements on the cardiovascular system of a dialysis patient, having a device according to claim 1, as well as an evaluation unit, which has an input channel for reading in at least one of a measurement signal of the sensor for measuring the temperature of blood to be dialyzed and of the sensor for measuring an indicator concentration in blood to be dialyzed, as well asat least one of another input channel for reading in and an input unit for inputting at least one characteristic variable characterizing a bolus injection,

24. System according to claim 23, wherein the program technology design of the evaluation unit includes a function for determining the filling status of the dialysis patient.

25. System according to claim 24, wherein the evaluation unit furthermore has a control channel for controlling a hemodialyzer, and the program technology design of the evaluation unit has a control function for influencing the fluid balance of blood flowing through the hemodialyzer, as a function of the filling status.

26. System according to claim 23, which has a hemodialyzer.

27. Method of setting up a dilution measurement site on a hemodialyzer, said method including the steps of connecting an arterial connection piece to a hemodialyzer input,connecting said arterial connection piece to an arterial blood vessel access,installing at least one of a sensor for measuring the temperature of blood to be dialyzed and a sensor for measuring an indicator concentration in blood to be dialyzed,connecting a venous connection piece, having an injection channel for injecting a bolus into dialyzed blood that flows through the venous connection piece, to a hemodialyzer output, andconnecting said venous connection piece to a venous blood vessel access.

28. Method according to claim 27, wherein, for said arterial connection piece, an arterial connection piece is used into which at least one of said sensor for measuring the temperature of blood to be dialyzed and said sensor for measuring an indicator concentration in blood to be dialyzed is integrated.

29. Method of carrying out thermodilution measurements on the cardiovascular system of a dialysis patient, said method including the steps of setting up a dilution measurement site on a hemodialyzer by connecting an arterial connection piece to a hemodialyzer input, connecting said arterial connection piece to an arterial blood vessel access, installing a sensor for measuring the temperature of blood to be dialyzed, connecting a venous connection piece, having an injection channel for injecting a bolus into dialyzed blood that flows through the venous connection piece, to a hemodialyzer output, and connecting said venous connection piece to a venous blood vessel access,injecting said bolus into said dialyzed blood through said injection channel, wherein said bolus has a temperature different from said dialyzed blood,acquiring at least one variable characterizing said bolus injection, said at least one variable including at least one of temperature of said bolus injected,amount of said bolus injected and duration of said injection of said bolus,measuring, using said sensor, the temperature of the blood to be dialyzed over time,evaluating a transpulmonary diffusion measurement, in that at least one hemodynamic parameter is determined proceeding from the measured temperature of the blood to be dialyzed over time and the at least one variable characterizing said bolus injection.

30. Method according to claim 29, wherein, for said arterial connection piece, an arterial connection piece is used into which said sensor for measuring the temperature of the blood to be dialyzed is integrated.