Apparatus for extracorporeal blood treatment

Patent metadata

Field	Value
Publication number	US-9533087-B2
Application number	US-201113876368-A
Country	US
Kind code	B2
Filing date	Sep 8, 2011
Priority date	Sep 30, 2010
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

An apparatus for extracorporeal blood treatment, comprising a treatment unit ( 2 ) having a first chamber ( 3 ) and a second chamber ( 4 ) separated from one another by a semipermeable membrane ( 5 ), a blood removal line ( 6 ) connected in inlet with the first chamber ( 3 ) and a blood return line ( 7 ) connected in outlet with the first chamber; an infusion line ( 9; 9 a, 9 b ) of a replacement fluid and a fluid evacuation line ( 10 ) connected in outlet from the second chamber. A regulating device ( 20 ) of a transmembrane pressure is active on at least one of the lines and a control unit ( 15 ) is configured to: command the regulating device ( 20 ) by setting a first increase (STMP 1 ), determine a value of a control parameter (φ 1 ) corresponding to the first increase, compare the value of the control parameter (φ 1 ) with a reference value (φ ref ) and, if the value of the control parameter is greater than the reference value, command the regulating device ( 20 ) by setting a second increase (STMP 2 ) which is greater than the first increase (STMP 1 ).

First claim

The invention claimed is:

1. An apparatus for extracorporeal blood treatment, comprising:
at least one treatment unit having at least one first chamber and at least one second chamber which are separated from one another by a semipermeable membrane;
at least one blood removal line connected with an inlet port of the first chamber and configured to remove blood from a patient;
at least one blood return line connected to an outlet port of the first chamber and configured to return treated blood to the patient;
at least one infusion line of a replacement fluid, the at least one infusion line connected to one of said blood removal line and blood return line;
at least one fluid evacuation line connected to an outlet port of the second chamber in order to receive at least one fluid that has been filtered across the semipermeable membrane;
a regulating device of a transmembrane pressure between the first chamber and the second chamber of the treatment unit, the regulating device being active on at least one of the lines; and
a control unit connected with the regulating device and configured such as to perform a setting sequence of the transmembrane pressure, the setting sequence comprising:
commanding the regulating device by setting a first increase (δTMP 1 ) at a first value of the transmembrane pressure (TMP 1 ) in order to reach a second transmembrane pressure (TMP 2 );
determining a value of a control parameter (φ 1 ) corresponding to the first increase in transmembrane pressure;
comparing the value of the control parameter (φ 1 ) with a reference value (φ ref ) and, if the value of the control parameter is greater than the reference value, commanding the regulating device by imposing a second increase (δTMP 2 ) on the transmembrane pressure which is greater than the first increase (δTMP 1 ) in order to reach a third value of the transmembrane pressure (TMP 3 );
wherein after reaching the third value of the transmembrane pressure (TMP 3 ), the setting sequence further comprises:
determining a value of a control parameter (φ n ) corresponding to an nth transmembrane pressure increase;
comparing the value of the control parameter (φ n ) with a reference value (φ ref(n) ) and, if the value of the control parameter (φ n ) is greater than the reference value (φ ref(n) ), determining an (n+1)th increase (δTMP n+1 ) of an entity which is greater than the entity of the nth increase (δTMP n ); and
commanding the regulating device to impose the (n+1)th increase (δTMP n+1 ) on the transmembrane pressure.

2. The apparatus of claim 1 , wherein the control parameter comprises a parameter selected from:
a variation between replacement flow in the infusion line at the first transmembrane pressure value (TMP 1 ) and the replacement flow in the infusion line at the second transmembrane pressure (TMP 2 );
variation between the ultrafiltration flow (Q UF ) across the membrane at the first transmembrane pressure value (TMP 1 ) and the ultrafiltration flow at the second transmembrane pressure value (TMP 2 );
replacement flow in the infusion line at the second transmembrane pressure value (TMP 2 );
ultrafiltration flow through the membrane at the second transmembrane pressure value (TMP 2 );
variation between replacement flow in the infusion line at the nth transmembrane pressure value (TMP n ) and the replacement flow in the infusion line at the (n+1)th transmembrane pressure value (TMP n+1 );
variation between ultrafiltration flow (Q UF ) across the membrane at the nth transmembrane pressure value (TMP n ) and the ultrafiltration flow at the (n+1)th transmembrane pressure (TMP n+1 );
replacement flow in the infusion line at the (n+1)th transmembrane pressure (TMP n+1 );
ultrafiltration flow through the membrane at the (n+1)th transmembrane pressure (TMP n+1 ).

3. The apparatus of claim 1 , wherein the setting sequence comprises terminating the setting sequence and imposing the second pressure value (TMP 2 ) as a setting value of the transmembrane pressure, if the value of the control parameter is less than the reference value.

4. The apparatus of claim 1 , wherein the control unit is configured to calculate the (n+1)th increase (δTMP n+1 ) as a function of the value of the control parameter corresponding to the nth transmembrane pressure increase (δTMP n ).

5. The apparatus of claim 1 , wherein the control unit is configured to calculate the (n+1)th increase (δTMP n+1 ) as a function of the control parameter value (φ n ) corresponding to the nth increase (δTMP n ) and the value of the nth transmembrane pressure increase (δTMP n ) using the formula:
δTMP n+1 =(φ n )·( K )

where:
K is the relation between the value of the nth transmembrane pressure increase (δTMP n ) and the value of a correcting factor (φ c );
δTMP n+1 is the (n+1)th transmembrane pressure increase;
and wherein the correcting factor value is selected from a group comprising:
a predetermined value,
a mathematical function of the reference value (φ ref ),
a mathematical function of a treatment mode to which the apparatus has been set,
a mathematical function of a treatment mode to which the apparatus has been set and the reference value (φ ref ).

6. The apparatus of claim 1 wherein the control parameter comprises a parameter selected from:
variation between replacement flow in the infusion line at the nth transmembrane pressure value (TMP n ) and the replacement flow in the infusion line at the (n+1)th transmembrane pressure value (TMP n+1 );
variation between ultrafiltration flow (Q UF ) across the membrane at the nth transmembrane pressure value (TMP n ) and the ultrafiltration flow at the (n+1)th transmembrane pressure (TMP n+1 );
wherein commanding the regulating device to impose a transmembrane pressure increase (δTMP 1 ; δTMP 2 ; δTMP n ), comprises varying a flow rate through the at least one infusion line in accordance with a predetermined control strategy;
and wherein n varies from 1 to the total number of pressure increases set during the sequence.

7. The apparatus of claim 1 , wherein the control unit is configured to verify that each increase in pressure is lower than a maximum safety value.

8. The apparatus of claim 1 , wherein the control unit is programmed such that during the setting sequence, following each command to increase the transmembrane pressure, a time transitory (T r ) is comprised before effecting a subsequent transmembrane pressure increase.

9. The apparatus of claim 8 , wherein the duration of time transitory (T r ) is not uniform, and is a function of the pressure increase between a transmembrane pressure value (TMP n ) and a next transmembrane pressure value (TMP n+1 ).

10. The apparatus of claim 8 , wherein the control unit is programmed such that each stage of comparing the value of a control parameter (φ 1 ; φ n ) with a respective reference value (φ ref ) is performed after the time transitory (T r ).

11. The apparatus of claim 1 , wherein the regulating device comprises at least one first pump located on the evacuation line, the control unit imposing the pressure increases by regulating a flow rate of the first pump.

12. The apparatus of claim 1 , wherein the regulating device comprises at least one second pump located on the infusion line, the control unit being configured to regulate the second pump at least according to:
a set value of treatment time, a set value of weight loss and the current value of the ultrafiltration flow across the membrane; or, alternatively,
a set value of the volume of total infusion to be attained at the end of treatment and a set value for weight loss to be attained at end of treatment.

1

Assignees

• Suffritti Mauro
• Carpani Michela
• Gambro Lundia Ab

Inventors

• Suffritti Mauro
• Carpani Michela

Classifications

• A61M1/1615

  using measurements made at different flow rates · CPC title

• A61M2205/502

  User interfaces, e.g. screens or keyboards · CPC title

• A61M1/3441 Primary

  Substitution rate control as a function of the ultrafiltration rate · CPC title

• A61M2205/52

  with memories providing a history of measured variating parameters of apparatus or patient · CPC title

• B01D61/22

  Controlling or regulating · CPC title