Initialization of a dosing unit for drug infusion

Patent metadata

Field	Value
Publication number	US-10159784-B2
Application number	US-201515126628-A
Country	US
Kind code	B2
Filing date	Feb 18, 2015
Priority date	Mar 17, 2014
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

Disclosed is a method for initializing a dosing unit ( 20 ) of an ambulatory infusion system, the method including carrying out a first priming routine. The first priming routine includes: providing the dosing unit ( 20 ) with a dosing chamber ( 202 ) having a minimal dosing chamber volume, a draining valve ( 205 ) being closed and a filling valve ( 204 ) being open. The first priming routine further includes measuring an initial reservoir fluid pressure p 2 and computing, a first priming volume v 1 . The method further includes increasing the dosing chamber volume by the first priming volume v 1 , with the first priming volume v 1 being computed such that a reservoir coupling conduit is filled with liquid drug substantially completely at the end of the dosing chamber volume increasing. The first priming routine further includes closing the filling valve ( 204 ) and opening the draining valve ( 205 ) and emptying the dosing unit ( 20 ) by decreasing the dosing chamber volume to the minimal dosing chamber volume. Disclosed are further a control unit for controlling operation of a dosing unit as well as an ambulatory infusion device.

First claim

The invention claimed is:

1. Method for initializing a dosing unit of an ambulatory infusion system, the method including carrying out a first priming routine, the first priming routine including:
providing the dosing unit with a dosing chamber of the dosing unit having a minimal dosing chamber volume, a draining valve of the dosing unit being closed and a filling valve of the dosing unit being open;
measuring an initial reservoir fluid pressure p 2 and computing, based on the initial reservoir fluid pressure p 2 , a first priming volume v 1 , with a liquid drug reservoir being fluidically coupled with the dosing chamber via a reservoir coupling conduit and the opened filling valve;
increasing the dosing chamber volume by the first priming volume v 1 , with the first priming volume v 1 being computed such that the reservoir coupling conduit is filled with liquid drug substantially completely at the end of the dosing chamber volume increasing;
closing the filling valve and opening the draining valve;
emptying the dosing unit by decreasing the dosing chamber volume to the minimal dosing chamber volume.

2. Method according to claim 1 , wherein the method further includes, prior to carrying out the first priming routine, carrying out a sensor calibration routine, the sensor calibration routine including:
providing the dosing unit in an initial state with the dosing chamber being gas-filled and both of the filling valve and the draining valve being closed, resulting in the dosing chamber being fluidic isolated;
decreasing the dosing chamber volume, thereby compressing the gas inside the dosing unit to a compression factor c 1 ;
reading, at the compression factor c 1 , an output value p 1 * of a pressure sensor in fluidic coupling with the dosing chamber and computing, based on the output value p 1 * and the compression factor c, a pressure sensor calibration, and storing the computed calibration;
opening the draining valve with the filling valve staying closed; and
emptying the dosing unit by further decreasing the dosing chamber volume to the minimal dosing chamber volume.

3. Method according to claim 1 , wherein the method further includes, following carrying out the first priming routine, carrying out a second priming routine, the second priming routine including:
closing the draining valve and opening the filling valve;
increasing the dosing chamber volume by a second priming volume;
closing the filling valve with the draining valve staying closed, resulting in the dosing chamber being fluidic isolated;
varying the dosing chamber volume and monitoring, during the variation, a dosing chamber pressure p C , and stopping the variation upon the dosing chamber pressure p C equalling a reference pressure; and
computing, based on an amount of variation of the dosing chamber volume, an air volume V air of air inside the dosing chamber.

4. Method according to claim 3 , wherein the second priming routine includes: the comparing the air volume V air with a pre-set threshold air volume V air,threshold and providing an alert if the air volume V air exceeds the pre-set threshold air volume V air,threshold .

5. Method according to claim 3 , wherein the second priming routine includes: taking into account a mechanical compliance of limiting walls of the dosing chamber for computing the air volume V air .

6. Method according to claim 1 , wherein the minimal dosing chamber volume is negligible or zero.

7. Method according to claim 1 , wherein the first priming routine includes: computing the first priming volume v 1 as

v
1

=

V
0

·

p
ref

p
ref

+

p
2

+

V
S

,

with V 0 being the fluidic volume of the reservoir coupling conduit, P ref being a reference pressure, and V s being a safety margin volume.

8. Method according to claim 1 , wherein increasing of the dosing chamber volume is achieved by displacing a piston of the dosing unit into a distal direction, and wherein decreasing of the dosing chamber volume is achieved by displacing the piston into an opposite proximal direction, with the piston being received in a dosing cylinder of the dosing unit and the dosing cylinder extending along a piston displacement axis, thus forming a movable limiting wall of the dosing chamber.

9. Method according to claim 1 , wherein opening and closing of the filling valve and the draining valve between an open and a closed state includes rotating a common shutoff body of the dosing unit.

10. Control unit, the control unit being designed for controlling operation of a dosing unit of an ambulatory infusion system, the control unit including a dosing chamber volume controller, a valve controller and a pressure sensor interface, the control unit being further designed for controlling execution of an initialization routine, the initialization routine including a first priming routine, the first priming routine causes the control unit to:
provide a dosing chamber of the dosing unit with a minimal dosing chamber volume, a draining valve of the dosing unit and open a filling valve of the dosing unit;
measure an initial reservoir fluid pressure p 2 and compute, based on the initial reservoir fluid pressure p 2 , a first priming volume v 1 , with the liquid drug reservoir being fluidically coupled with the dosing chamber via a reservoir coupling conduit and the opened filling valve;
increase the dosing chamber volume by the first priming volume v 1 , with the first priming volume v 1 being computed such that the reservoir coupling conduit is filled with liquid drug substantially completely at the end of the increase in the dosing chamber volume;
close the filling valve and open the draining valve; and
empty the dosing unit by a decrease in the dosing chamber volume to the minimal dosing chamber volume.

11. Control unit according to claim 10 , the control unit being further designed for controlling, prior to controlling execution of the first priming routine, execution of a sensor calibration routine, the sensor calibration routine causes the control unit to:
close the filling valve and the draining valve, which results in the dosing chamber being fluidic isolated;
decrease the dosing chamber volume, thereby compressing gas inside the dosing unit to a compression factor c 1 ;
read, at the compression factor c 1 , an output value p 1 * of a pressure sensor in fluidic coupling with the dosing chamber and compute, based on the output value p 1 * and the compression factor c, a pressure sensor calibration, and store the computed calibration;
open the draining valve with the filling valve staying closed; and
empty the dosing unit by a further decrease in the dosing chamber volume to the minimal dosing chamber volume.

12. Control unit according to clai

Assignees

• Roche Diabetes Care Inc

Inventors

• Teutsch David
• Kettenmann Peter

Classifications

• A61M5/14216 Primary

  Reciprocating piston type · CPC title

• A61M5/36

  with means for eliminating or preventing injection or infusion of air into body (dialysis systems, blood oxygenators A61M1/14; haemofiltration equipment A61M1/34; {automatic tube cut-off A61M39/281}) · CPC title

• A61M2205/103

  rotating · CPC title

• A61M5/14244 Primary

  adapted to be carried by the patient, e.g. portable on the body · CPC title

• A61M2005/1402

  Priming · CPC title