# US 2016/0354528 A1 · Apparatus for extracorporeal treatment of blood

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- Number: US 2016/0354528 A1
- Document ID: US20160354528A1
- Status: Published application
- Kind: A1
- Application number: 15/240,231
- Filed: 2016-08-18
- Published: 2016-12-08
- Earliest claimed: 2012-03-28
- Assignees: Gambro Lundia AB
- Applicants: Gambro Lundia AB
- Inventors: Dominique Pouchoulin
- Web page: https://patentgrep.com/patent/US20160354528A1

## CPC

- A61M 1/1647: {with flow rate measurement of the dialysis fluid, upstream and downstream of the dialyser}
- A61M 1/16: with membranes
- A61M 1/1605: {Physical characteristics of the dialysate fluid}
- A61M 1/1643: {with weighing of fresh and used dialysis fluid}
- A61M 1/34: Filtering material out of the blood by passing it through a membrane, i.e. hemofiltration or diafiltration
- A61M 1/3403: {Regulation parameters}
- A61M 1/341: {by measuring the filtrate rate or volume}
- A61M 1/3413: {Diafiltration}
- A61M 1/3434: {with pre-dilution and post-dilution}
- A61M 1/3441: {Substitution rate control as a function of the ultrafiltration rate}
- A61M 1/3451: {the difference in weight between both ultra-filtrate and substitution reservoir being used as control signal}
- A61M 1/361: {before treatment}
- A61M 1/3638: {with a vapour trap}
- A61M 2205/18: with alarm
- A61M 2205/3334: Measuring or controlling the flow rate
- A61M 2205/3393: by weighing the reservoir
- A61M 2205/502: User interfaces, e.g. screens or keyboards
- A61M 2205/505: Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches
- A61M 2205/52: with memories providing a history of measured variating parameters of apparatus or patient
- A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)}

## Abstract

An apparatus for extracorporeal treatment of blood (1) comprising a filtration unit (2), a blood withdrawal line (6), a blood return line (7), an effluent fluid line (13), a pre and/or post-dilution fluid line (15, 25) connected to the blood withdrawal line, and a dialysis fluid line. Pumps (17, 18, 21, 22, 27) act on the fluid lines for regulating the flow of fluid. A control unit (10) is configured to periodically calculate a new value for the patient fluid removal rate to be imposed on an ultrafiltration actuator in order to keep a predefined patient fluid removal rate across a reference time interval irrespective of machine down times.

## Claims

### Claim at position 1

1-26. (canceled)

### Claim 27

A process of controlling an apparatus for extracorporeal treatment of blood, the apparatus being of the type comprising: a filtration unit having a primary chamber and a secondary chamber separated by a semi-permeable membrane; a blood withdrawal line connected to an inlet of the primary chamber connected to an outlet of the primary chamber said blood lines being designed to be connected to a patient cardiovascular system; a blood pump for controlling the flow of blood through the blood lines; an effluent fluid line connected to an outlet of the secondary chamber; an ultrafiltration actuator connected to the effluent fluid line and configured to cause a transfer of fluid from the primary (3) to the secondary chamber, wherein the process comprises:
controlling the ultrafiltration actuator based on a set value for patient fluid removal rate, said set value being a desired value for the rate of fluid removal from the patient,
determining when the ultrafiltration actuator is operated and/or when the ultrafiltration actuator is not operated,
executing at check points during patient treatment a control procedure comprising:
receiving one check information selected in the group of:
an effective time portion, of said time period preceding a check point, during which said ultrafiltration actuator is operated, a down time portion, of said time period preceding a check point, during which said ultrafiltration actuator is not operated,
calculating an updated value for said fluid removal rate as a function of said set value for a fluid removal rate and of said check information.

### Claim 28 (depends on 27)

A process according to claim 27 wherein the control procedure further comprises, after calculating said updated value, controlling the ultrafiltration actuator after the check point as a function of said updated value for the fluid removal rate.

### Claim 29

(canceled)

### Claim 30 (depends on 27)

A process according to claim 27, wherein the process further comprises re-executing said control procedure at a plurality of check points during patient treatment, said plurality of check points comprising one or more in the group of:
check points at regular intervals,
periodic check points,
check points triggered by specific setting of a new set value for patient fluid removal rate,
check points triggered by a stop in the ultrafiltration actuator,
check points triggered by each time a flow rate setting is changed.

### Claim 31 (depends on 27)

A process according to claim 27, wherein the control procedure comprises:
determining a value of the fluid removed from the patient over a time period preceding a check point;
determining a value of fluid to be removed from the patient over a time period following the check point in order to achieve the set value for fluid removal rate over the sum of the time period preceding check point and of the time period following the check point;
calculating the updated value for said fluid removal rate based on said set value for a fluid removal rate, on said value of fluid to be removed from the patient over the time period following the check point and on the duration of the time period following the check point.

### Claim 32 (depends on 31)

A process according to claim 31 wherein the control procedure comprises calculating the updated value for said fluid removal rate at check point according to the formula:
Qpfr_new=[(Tretro+Tprosp)·Qpfr_set−Vpfr_removed]/Tprosp
where:
Qpfr_new is the calculated updated value for said fluid removal rate;
Qpfr_set is the set value for fluid removal rate;
Vpfr_removed is the value of the fluid removed from the patient over time period (Tretro) preceding a check point 40;
Tretro is a time period preceding check point;
Tprosp is a time period following the check point;
(Tretro+Tprosp) is the sum of the time period (Tretro) preceding the check point and of the time period (Tprosp) following the check point.

### Claim 33

(canceled)

### Claim 34 (depends on 27)

A process according to claim 27, the control procedure comprises calculating the updated value for said fluid removal rate at a selected check point between a start time and an end time according to the formula:
Qpfr_new=(ΔT·Qpfr_set−Vpfr(0))/[(T00+(k+1)·ΔT)−Ti]
or
Qpfr_new=(2·ΔT·Qpfr_set−Vpfr(0)−Vpfr(k-1))/[(T00+(k+1)·ΔT)−Ti]
where:
Qpfr_new is the updated value for fluid removal rate;
Qpfr_set is the set value for fluid removal rate;
(T00+k·ΔT) is the start time;
T00+(k+1)·ΔT is the end time;
Ti is the selected check point;
Vpfr(0) is the value of the fluid removed from the patient over a first time window running from the start time (T00+k·ΔT) to the selected check point;
Vpfr(k-1) is the value of the fluid removed from the patient over a second time window running from the start time (T00+(k−1)·ΔT) to the end time (T00+k·ΔT);
[(T00+(k+1)·ΔT)−Ti] is the duration of a time period following the selected check point;
ΔT is a reference time interval of prefixed duration.

### Claim 35 (depends on 31)

A process according to claim 31, wherein the control procedure comprises:
determining an effective portion of said time period following the check point, during which it is forecasted that the ultrafiltration actuator will be actually pulling fluid from the primary chamber into the secondary chamber;
calculating the updated value for said fluid removal rate using said effective portion in place of the duration of the time period following the check point.

### Claim 36 (depends on 35)

A process according to claim 35 wherein the effective portion is calculated by reducing the duration of the time period following the check point by a quantity linked to one or more of: the number of bag changes expected in the next time period, down times caused by alarm conditions, down times caused by alarm conditions if the duration of the time period following the check point is greater than a prefixed duration.

### Claim at position 12

37-41. (canceled)

### Claim 42 (depends on 27)

A process according to claim 27, wherein the control procedure comprises comparing the calculated updated value for said fluid removal rate against a maximum threshold value before using it for controlling the ultrafiltration actuator.

### Claim 43 (depends on 27)

A process according to claim 27, wherein the control procedure comprises executing one or more of the following safety checks:
comparing the ratio between the calculated updated value and the set value for the patient fluid removal rate with a first boundary condition,
comparing the absolute difference between the calculated updated value and the set value for the patient fluid removal rate with a second boundary condition,
comparing the absolute difference between the calculated updated value and the set value for the patient fluid removal rate as a function of patient body weight with a third boundary condition,
wherein the control procedure comprises verifying that a prefixed number of said safety checks is positively passed before using the updated value for controlling the ultrafiltration actuator.

### Claim at position 15

44-65. (canceled)

### Claim 67

A process of controlling an apparatus for extracorporeal treatment of blood, the apparatus being of the type comprising: a filtration unit having a primary chamber and a secondary chamber separated by a semi-permeable membrane; a blood withdrawal line connected to an inlet of the primary chamber, and a blood return line connected to an outlet of the primary chamber said blood lines being designed to be connected to a patient cardiovascular system; a blood pump for controlling the flow of blood through the blood lines; an effluent fluid line connected to an outlet of the secondary chamber; an ultrafiltration actuator connected to the effluent fluid line and configured to cause a transfer of fluid from the primary to the secondary chamber, wherein the process comprises:
controlling the ultrafiltration actuator based on a set value for patient fluid removal rate, said set value being a desired value for the rate of fluid removal from the patient,
executing at check points during patient treatment a control procedure comprising:
receiving one check information selected in the group of:
an effective time portion, of a time period preceding a check point, during which said ultrafiltration actuator is operated,
a down time portion, of a time period preceding a check point, during which said ultrafiltration actuator is not operated;
calculating an updated value for said fluid removal rate as a function of said set value for a fluid removal rate and of said check information;
after calculating said updated value, controlling the ultrafiltration actuator after the check point as a function of said updated value for the fluid removal rate.

### Claim 68 (depends on 67)

A process according to claim 67, wherein the process further comprises re-executing said control procedure at a plurality of check points during patient treatment, said plurality of check points comprising one or more in the group of:
check points at regular intervals,
periodic check points,
check points triggered by specific setting of a new set value for patient fluid removal rate,
check points triggered by a stop in the ultrafiltration actuator,
check points triggered by each time a flow rate setting is changed.

### Claim 69 (depends on 67)

A process according to claim 67, wherein the control procedure comprises:
determining a value of the fluid removed from the patient over a time period preceding a check point;
determining a value of fluid to be removed from the patient over a time period following the check point in order to achieve the set value for fluid removal rate over the sum of the time period receding check point and of the time period following the check point;
calculating the updated value for said fluid removal rate based on said set value for a fluid removal rate, on said value of fluid to be removed from the patient over the time period following the check point, and on the duration of the time period following the check point, wherein calculating the updated value for said fluid removal rate comprises using the formula:
Qpfr_new[(Tretro+Tprosp)·Qpfr_set−Vpfr_removed]/Tprosp
where:
Qpfr_new is the calculated updated value for said fluid removal rate;
Qpfr_set is the set value for fluid removal rate;
Vpfr_removed is the value of the fluid removed from the patient over time period Tretro preceding a check point;
Tretro is a time period preceding the check point;
Tprosp is a time period following the check point;
(Tretro+Tprosp) is the sum of the time period (Tretro) preceding the check point and of the time period (Tprosp) following the check point.

### Claim 70 (depends on 67)

A process according to claim 67, wherein the control procedure comprises calculating the updated value for said fluid removal rate at a selected check point between a start time and an end time according to the formula:
Qpfr_new(ΔT·Qpfr_set−Vpfr(0))/[(T00+(k+1)·ΔT)−Ti]
or
Qpfr_new=(2·ΔT·Qpfr_set−Vpfr(0)−Vpfr(k-1))/[(T00+(k+1)·ΔT)−Ti]
where:
Qpfr_new is the updated value for fluid removal rate;
Qpfr_set is the set value for fluid removal rate;
(T00+k·ΔT) is the start time;
T00+(k+1)·ΔT is the end time;
Ti is the selected check point;
Vpfr(0) is the value of the fluid removed from the patient over first time window running from the start time (T00+k·ΔT) to the selected check point (Ti);
Vpfr(k-1) is the value of the fluid removed from the patient over a second time window running from the start time (T00+(k−1)·ΔT) to the end time (T00+k·ΔT);
[(T00+(k+1)·ΔT)−Ti] is the duration of a time period following the selected check point (Ti);
ΔT is a reference time interval of prefixed duration.

### Claim 71

A process of controlling an apparatus for extracorporeal treatment of blood, the apparatus being of the type comprising: a filtration unit having a primary chamber and a secondary chamber separated by a semi-permeable membrane; a blood withdrawal line connected to an inlet of the primary chamber, and a blood return line connected to an outlet of the primary chamber said blood lines being designed to be connected to a patient cardiovascular system; a blood pump for controlling the flow of blood through the blood lines; an effluent fluid line connected to an outlet of the secondary chamber; an ultrafiltration actuator connected to the effluent fluid line and configured to cause a transfer of fluid from the primary to the secondary chamber, wherein the process comprises:
controlling the ultrafiltration actuator based on a set value for patient fluid removal rate, said set value being a desired value for the rate of fluid removal from the patient,
executing at check points during patient treatment a control procedure comprising:
receiving one check information selected in the group of:
a value of fluid removed from the patient over a time period preceding a check point,
an effective time portion, of a time period preceding a check point, during which said ultrafiltration actuator is operated,
a down time portion, of a time period preceding a check point, during which said ultrafiltration actuator is not operated;
determining an effective portion of a time period following the check point, during which it is forecasted that the ultrafiltration actuator will be actually pulling fluid from the primary chamber into the secondary chamber;
calculating an updated value for said fluid removal rate as a function of:
said set value for a fluid removal rate,
said effective portion of the time period following the check point, and
said check information;
after calculating said updated value, controlling the ultrafiltration actuator after the check point as a function of said updated value for the fluid removal rate.

### Claim 72 (depends on 71)

A process according to claim 71 wherein the effective portion is calculated by reducing the duration of the time period following check point by a quantity linked to one or more of:
number of bag changes expected in the next time period;
down times caused by alarm conditions;
down times caused by alarm conditions if the duration of the time period following the check point is greater than a prefixed duration.

### Claim 73 (depends on 71)

A process according to claim 71, wherein the control procedure comprises comparing the calculated updated value for said fluid removal rate against a maximum threshold value before using it for controlling the ultrafiltration actuator.

### Claim 74 (depends on 71)

A process according to claim 71, wherein the control procedure comprises executing one or more of the following safety checks:
comparing the ratio between the calculated updated value and the set value for the patient fluid removal rate with a first boundary condition,
comparing the absolute difference between the calculated updated value and the set value for the patient fluid removal rate with a second boundary condition,
comparing the absolute difference between the calculated updated value and the set value for the patient fluid removal rate as a function of patient body weight with a third boundary condition,
wherein the control procedure comprises verifying that a prefixed number of said safety checks is positively passed before using the updated value for controlling the ultrafiltration actuator.