Method for determining the distribution volume of a blood component during an extracorporeal blood treatment and device for carrying out the method
First Claim
1. A method for determining the distribution volume of a blood component in the body of an organism during an extracorporeal blood treatment, in which the blood to be treated flows in an extracorporeal circuit through the blood chamber of a dialyzer subdivided by a semipermeable membrane into the blood chamber and a dialyzing-fluid chamber, and dialyzing fluid flows in a dialyzing-fluid path through the dialyzing-fluid chamber of the dialyzer, comprising the following method steps:
- bringing about a change in the concentration of the blood component in the blood upstream of the dialyzer by a change in the concentration of the blood component in the dialyzing fluid upstream of the dialyzer; and
measuring the change in the concentration of the blood component in the dialyzing fluid downstream of the dialyzer which can be attributed to the change in the concentration of the blood component in the blood as a result of the change in the concentration of the blood component in the dialyzing fluid upstream of the dialyzer; and
determining the distribution volume V of the blood component from the change in the concentration of the blood component in the dialyzing fluid upstream and downstream of the dialyzer.
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Accused Products
Abstract
The invention relates to a method for determining the volume of distribution of a blood component in the body of a living organism, especially the volume of distribution of urea, during an extracorporeal blood treatment. According to this method, the blood to be treated flows through the blood chamber (3) of a dialysis machine (1) in an extracorporeal circuit, said dialysis machine being divided into said blood chamber and a dialysing liquid chamber (4) by a semipermeable membrane (2). Dialysing liquid flows through the dialysing liquid chamber of the dialysis machine in a dialysing liquid channel. The method is based on the determination of the temporal change in the concentration of the blood component in the blood upstream of the dialysis machine using the temporal variation in a physical or chemical characteristic of the dialysing liquid upstream and downstream of the dialysis machine and the determination of the volume of distribution of the substance in the body of a living organism using the temporal variation in the concentration of the blood component in the blood. The invention also relates to a device for the extracorporeal blood treatment, comprising a device for determining the volume of distribution of a blood component in the body of a living organism.
108 Citations
25 Claims
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1. A method for determining the distribution volume of a blood component in the body of an organism during an extracorporeal blood treatment, in which the blood to be treated flows in an extracorporeal circuit through the blood chamber of a dialyzer subdivided by a semipermeable membrane into the blood chamber and a dialyzing-fluid chamber, and dialyzing fluid flows in a dialyzing-fluid path through the dialyzing-fluid chamber of the dialyzer, comprising the following method steps:
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bringing about a change in the concentration of the blood component in the blood upstream of the dialyzer by a change in the concentration of the blood component in the dialyzing fluid upstream of the dialyzer; and measuring the change in the concentration of the blood component in the dialyzing fluid downstream of the dialyzer which can be attributed to the change in the concentration of the blood component in the blood as a result of the change in the concentration of the blood component in the dialyzing fluid upstream of the dialyzer; and determining the distribution volume V of the blood component from the change in the concentration of the blood component in the dialyzing fluid upstream and downstream of the dialyzer. - View Dependent Claims (2, 3, 4, 5)
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6. A method for determining the distribution volume of a blood component in the body of an organism during an extracorporeal blood treatment, in which the blood to be treated flows in an extracorporeal circuit through the blood chamber of a dialyzer subdivided by a semipermeable membrane into the blood chamber and a dialyzing-fluid chamber, and dialyzing fluid flows in a dialyzing-fluid path through the dialyzing-fluid chamber of the dialyzer, comprising the following method steps:
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the concentration of the blood component in the dialyzing fluid is altered in the dialyzing-fluid path upstream of the dialyzer and the concentration of the blood component in the dialyzing fluid is measured downstream of the dialyzer; the change as a function of time in the concentration of a blood component in the blood upstream of the dialyzer Δ
cbi as a result of the change in the concentration of the blood component in the dialyzing fluid upstream of the dialyzer is determined from the concentration of the blood component in the dialyzing fluid upstream and downstream of the dialyzer after the concentration of the blood component in the dialyzing fluid has been altered; andthe distribution volume V of the blood component is determined from the change as a function of time in the concentration of the blood component in the blood. - View Dependent Claims (7)
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8. A method for determining the distribution volume of a blood component in the body of an organism during an extracorporeal blood treatment, in which the blood to be treated flows in an extracorporeal circuit through the blood chamber of a dialyzer subdivided by a semipermeable membrane into the blood chamber and a dialyzing-fluid chamber, and dialyzing fluid flows in a dialyzing-fluid path through the dialyzing-fluid chamber of the dialyzer, comprising the following method steps:
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bringing about a change in the concentration of a blood component in the blood upstream of the dialyzer by a change in a physical or chemical characteristic in the dialyzing fluid upstream of the dialyzer; and measuring the change in the physical or chemical characteristic in the dialyzing fluid downstream of the dialyzer which can be attributed to the change in the concentration of the blood component in the blood; and determining the distribution volume V of the blood component from the change in the physical or chemical characteristic in the dialyzing fluid upstream and downstream of the dialyzer, wherein the physical or chemical characteristic of the dialyzing fluid in the dialyzing-fluid path is increased at a point of time t0 from a predetermined first value cdi0 to a predetermined second value cdi1, is reduced at a point of time t1>
t0 to a predetermined third value cdi2, and is increased at a point of time t2>
t1 to a predetermined fourth value cdi0 which is equal to the first value, the value by which the characteristic is increased being half as large as the value by which the characteristic is reduced.- View Dependent Claims (9, 10, 11)
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12. An apparatus for determining the distribution volume of a blood component in the body of an organism during an extracorporeal blood treatment in conjunction with an extracorporeal blood-treatment device, in which the blood to be treated flows in an extracorporeal circuit through the blood chamber of a dialyzer subdivided by a semipermeable membrane into the blood chamber and a dialyzing-fluid chamber, and dialyzing fluid flows in a dialyzing-fluid path through the dialyzing-fluid chamber of the dialyzer, having
a device configured to alter the concentration of the blood component in the dialyzing fluid in the dialyzing-fluid path upstream of the dialyzer, and a measuring device configured to determine the concentration of the blood component in the dialyzing fluid in the dialyzing-fluid path downstream of the dialyzer, wherein the apparatus comprises an arithmetic and evaluation configured in such a way that the distribution volume V of the blood component can be determined from a change in the concentration of the blood component in the dialyzing fluid downstream of the dialyzer which can be attributed to the change in the concentration of the blood component in the blood as a result of the change in the concentration of the blood component in the dialyzing fluid upstream of the dialyzer.
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19. An apparatus for determining the distribution volume of a blood component in the body of an organism during an extracorporeal blood treatment in conjunction with an extracorporeal blood-treatment device, in which the blood to be treated flows in an extracorporeal circuit through the blood chamber of a dialyzer subdivided by a semipermeable membrane into the blood chamber and a dialyzing-fluid chamber, and dialyzing fluid flows in a dialyzing-fluid path through the dialyzing-fluid chamber of the dialyzer, having
a device configured to alter the concentration of the blood component in the dialyzing fluid in the dialyzing-fluid path upstream of the dialyzer, and a measuring device configured to determine the concentration of the blood component in the dialyzing fluid in the dialyzing-fluid path downstream of the dialyzer, wherein the apparatus comprises an arithmetic and evaluation configured in such a way that the change as a function of time in the concentration of the blood component Δ - cbi in the blood upstream of the dialyzer as a result of the change in the concentration of the blood component in the dialyzing fluid upstream of the dialyzer can be determined from the concentration of the blood component in the dialyzing fluid upstream and downstream of the dialyzer after the concentration of the blood component in the dialyzing fluid has been altered, and the distribution volume V of the blood component can be determined from the change as a function of time in the concentration of the blood component upstream of the dialyzer.
- View Dependent Claims (20, 21, 22, 23)
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24. A method for determining the distribution volume of a blood component in the body of an organism during an extracorporeal blood treatment, in which the blood to be treated flows in an extracorporeal circuit through the blood chamber of a dialyzer subdivided by a semipermeable membrane into the blood chamber and a dialyzing-fluid chamber, and dialyzing fluid flows in a dialyzing-fluid path through the dialyzing-fluid chamber of the dialyzer, comprising the following method steps:
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a physical or chemical characteristic of the dialyzing fluid is altered in the dialyzing-fluid path upstream of the dialyzer, and the physical or chemical characteristic of the dialyzing fluid is measured downstream of the dialyzer; the change as a function of time in the concentration of a blood component in the blood upstream of the dialyzer Δ
cbi is determined from the physical or chemical characteristic of the dialyzing fluid upstream and downstream of the dialyzer; andthe distribution volume V of the blood component is determined from the change as a function of time in the concentration of a blood component in the blood, wherein the physical or chemical characteristic of the dialyzing fluid in the dialyzing-fluid path is increased at a point of time t0 from a predetermined first value cdi0 to a predetermined second value cdi1, is reduced at a point of time t1>
t0 to a predetermined third value cdi2, and is increased at a point of time t2>
t1 to a predetermined fourth value cdi0 which is equal to the first value, the value by which the characteristic is increased being half as large as the value by which the characteristic is reduced. - View Dependent Claims (25)
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Specification