Dialyser with Measuring Devices for Monitoring the Blood Pressure, Method of Determining the Blood Pressure and a Storage Medium for use in a Dialyser

• US 20090050544A1
• Filed: 03/05/2007
• Published: 02/26/2009
• Est. Priority Date: 03/07/2006
• Status: Active Grant

• Current Assignee: Fresenius Medical Care Deutschland GmbH (Fresenius Medical Care AG)
• Original Assignee: Fresenius Medical Care Deutschland GmbH (Fresenius Medical Care AG)
• Inventors: Zhang, Wei
• Granted Patent: US 8,303,807 B2
• Time in Patent Office: Days
• US Class Current: 210/90
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02125 of pulse wave propagation time
• CPC Class Codes: A61M 1/3639 Blood pressure control, pressure transducers specially adapted therefor
• CPC Class Codes: A61M 2230/30 Blood pressure A61M2230/04 takes precedence

Abstract

The invention relates to a dialyser having a blood-pressure measuring unit assigned to the dialyser, a pulse-wave-transit-time measuring system assigned to the dialyser and an evaluation unit, the evaluation unit being configured such that a signal representing the blood pressure can be derived from this pulse wave transit time; the parameters describing the relationship between the pulse wave transit time and the blood pressure can be determined from a plurality of measurements made by the blood-pressure measuring unit and simultaneous measurements made by the pulse-wave-transit-time measuring system, it being possible to determine at least two of these pairs of measured values at times when the absolute and/or the relative pulse-wave-transit-time deviation is above a threshold value. The invention relates further to a method of determining the parameters describing the relationship between a pulse-wave-transit-time signal and a blood-pressure-measurement signal, a signal representing the blood pressure subsequently being derived from the pulse wave transit time; the parameters describing the relationship between the pulse wave transit time and the blood pressure are determined from blood-pressure-measurement-signal values and simultaneous pulse-wave-transit-time values, at least two of these pairs of measured values being obtained at points in time when the absolute and/or the relative deviation of the pulse wave transit time and/or of the blood pressure is above a threshold value.

Claims

1. :

Dialyser having a blood-pressure measuring unit assigned to said dialyser, a pulse-wave-transit-time measuring system assigned to said dialyser and an evaluation unit,

wherein the evaluation unit is configured such that the parameters (m, n) describing the relationship between the pulse wave transit time and the blood pressure can be determined (208, 308) from measurements made by the blood-pressure measuring unit and simultaneous measurements made by the pulse-wave-transit-time measuring system, it being possible to determine at least two of these pairs of measured values at times when the absolute and/or the relative deviation of the pulse wave transit time and/or of the blood pressure is above a threshold value.

2. :

Dialyser according to claim 1, wherein for parameter determination, the pairs of measured values can be weighted (310) according to the times at which the values were recorded, the weighting being weaker for pairs of measured values recorded further back in time.

3. :

Dialyser according to claim 1, wherein the maximum and minimum blood pressures measured, together with the corresponding measured pulse wave transit times, can be used to determine the parameters describing the relationship between the pulse wave transit time and the blood pressure (208, 308).

4. :

Dialyser according to claim 1, wherein only such pairs of measured values as are obtained within a given time window can be used to determine the parameters describing the relationship (309).

5. :

Dialyser according to claim 1, wherein a data input unit is assigned or assignable to the dialyser, said input unit serving to supply pairs of values obtained by the measuring unit and the measuring system during earlier therapy sessions with the same patient to the evaluation unit from a storage medium.

6. :

Dialyser according to claim 5,

wherein the data input unit is simultaneously a data output unit with which the pairs of measured values from the current therapy session are written onto the storage medium.

11. :

Storage medium for use in a dialyser according to claim 5.

12. :

Storage medium according to claim 11,

wherein the storage medium is magnetic, optical or electrical.

7. :

Method of determining the parameters describing the relationship between a pulse-wave-transit-time signal and a blood-pressure-measurement signal, wherein the parameters (m, n) describing the relationship between the pulse wave transit time and the blood pressure are determined (208, 308) from a plurality of blood-pressure-measurement-signal values and simultaneous pulse-wave-transit-time values, at least two of these pairs of measured values being obtained at points in time when the absolute and/or the relative deviation of the pulse-wave-transit-time and/or of the blood-pressure-measurement-signal is above a threshold value.

8. :

Method according to claim 7,

wherein for parameter determination, the pairs of measured values are weighted (310) according to the times at which the values were recorded, the weighting being weaker for pairs of measured values recorded further back in time.

9. :

Method according to claim 7, wherein the maximum and minimum blood pressures measured, together with the corresponding measured pulse wave transit times, are used to determine the parameters describing the relationship between the pulse wave transit time and the blood pressure (208, 308).

10. :

Method according to claim 7, wherein only such pairs of measured values as are obtained within a given time window are used to determine the parameters describing the relationship (309).