Method for determining a treatment parameter on a haemofiltration device, and haemofiltration device for applying the method
First Claim
1. A method for determining a treatment parameter on a haemofiltration device having a blood cleansing element divided into first and second chambers by a semipermeable membrane, said first chamber forming part of an ultrafiltrate outlet system and said second chamber forming part of an extracorporeal blood circulation system, the device also having a substitution-fluid addition system with which substitution fluid can be added to the extracorporeal blood circulation system, the method comprising the steps of:
- determining a fluid flow Qo led away from the first chamber;
determining a first physical-chemical characteristic Cs1 in the substitution fluid and a corresponding first physical-chemical characteristic Cf1 in the fluid led away;
changing the physical-chemical characteristic Cs in the substitution fluid;
determining a second physical-chemical characteristic Cs2 in the substitution fluid and a second corresponding physical-chemical characteristic Cf2 in the fluid led away; and
determining a treatment parameter from the determined values of the fluid flow Qo led away, the physical-chemical characteristics Cs1 and Cs2 in the substitution fluid, and the physical-chemical characteristics Cf1 and Cf2 in the fluid led away.
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Accused Products
Abstract
A method for determining a treatment parameter on a haemofiltration device, as well as a haemofiltration device for applying the method, based on the recognition that a determination method known from haemodialysis can, with little modification, be transferred to haemofiltration. To this effect a physical-chemical characteristic of the substitution fluid and of the fluid which is removed from the haemofilter by way of an ultrafiltrate outlet pipe, is determined. Furthermore, this characteristic is acquired before, after or during a change of this characteristic in the substitution fluid, and is evaluated. As a result, the ion dialysance and thus the urea clearance of a haemofiltration device, which can also be operated as a haemodiafiltration device, can be determined.
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Citations
30 Claims
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1. A method for determining a treatment parameter on a haemofiltration device having a blood cleansing element divided into first and second chambers by a semipermeable membrane, said first chamber forming part of an ultrafiltrate outlet system and said second chamber forming part of an extracorporeal blood circulation system, the device also having a substitution-fluid addition system with which substitution fluid can be added to the extracorporeal blood circulation system, the method comprising the steps of:
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determining a fluid flow Qo led away from the first chamber;
determining a first physical-chemical characteristic Cs1 in the substitution fluid and a corresponding first physical-chemical characteristic Cf1 in the fluid led away;
changing the physical-chemical characteristic Cs in the substitution fluid;
determining a second physical-chemical characteristic Cs2 in the substitution fluid and a second corresponding physical-chemical characteristic Cf2 in the fluid led away; and
determining a treatment parameter from the determined values of the fluid flow Qo led away, the physical-chemical characteristics Cs1 and Cs2 in the substitution fluid, and the physical-chemical characteristics Cf1 and Cf2 in the fluid led away. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A haemofiltration device comprising:
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a blood cleansing element divided into two chambers by a semipermeable membrane, with a first chamber forming part of an ultrafiltrate outlet system and a second chamber forming part of an extracorporeal blood circulation system;
said extracorporeal blood circulation system including a blood inlet pipe which leads to the second chamber, and a blood outlet pipe which removes blood from the second chamber;
said ultrafiltrate outlet system including an ultrafiltrate outlet pipe which removes the fluid from the first chamber, and an ultrafiltrate conveyance device for targeted fluid removal from a removal flow Qo through the membrane via the ultrafiltrate outlet pipe;
a substitution fluid addition system having a substitution fluid pipe which leads from a source for the provision of substitution fluid to the extracorporeal blood circulation system, and a substitution conveyance device for conveying substitution fluid in the substitution fluid pipe;
a first sensor element arranged on the substitution fluid pipe for determining a physical-chemical characteristic Cs of the substitution fluid;
a second sensor element arranged on the ultrafiltrate outlet pipe for determining the corresponding physical-chemical characteristic Cf of the fluid led away;
a device for changing the physical-chemical property Cs of the substitution fluid; and
an evaluation and control unit which records first measured values Cs1 and Cf1 of the first and second sensor elements, respectively, and then controls said device for changing the physical-chemical characteristic of the substitution fluid so as to effect a change in said physical-chemical characteristic;
said evaluation and control unit recording second measured values Cs2 and Cf2 of the first and second sensor elements, respectively, said second values having changed from said first values because of the change in said physical-chemical characteristic; and
said evaluation and control unit determining a treatment parameter from the values Cs1, Cs2, Cf1, Cf2, and Qo. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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Specification