Micropump for peristaltic pumping of a liquid medium

• US 20080038128A1
• Filed: 03/14/2007
• Published: 02/14/2008
• Est. Priority Date: 03/14/2006
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: Haar, Hans-Peter
• Granted Patent: US 7,985,057 B2
• Time in Patent Office: Days
• US Class Current: 417/474
• CPC Class Codes: A61M 2205/0294 Piezoelectric materials
• CPC Class Codes: A61M 2205/18 with alarm
• CPC Class Codes: A61M 2205/3306 Optical measuring means
• CPC Class Codes: A61M 2205/3313 used specific wavelengths
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/3375 Acoustical, e.g. ultrasonic, measuring means
• CPC Class Codes: A61M 5/14228 with linear peristaltic action, i.e. comprising at least three pressurising members or a helical member
• CPC Class Codes: A61M 5/14232 Roller pumps
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/16886 for measuring fluid flow rate, i.e. flowmeters
• CPC Class Codes: A61M 5/365 Air detectors A61M5/1684 takes precedence; in extracorporeal blood circuits A61M1/3626
• CPC Class Codes: F04B 43/082 the tubular flexible member being pressed against a wall by a number of elements, each having an alternating movement in a direction perpendicular to the axes of the tubular member and each having its own driving mechanism

Abstract

The invention relates to a micropump for peristaltic pumping of a liquid medium and to a device which contains a peristaltic micropump and which is for metered administration of a liquid drug.

Claims

1. A micropump for peristaltic pumping of a liquid medium, the micropump comprising:

at least one flow channel with a wall element, the flow channel having a cross-sectional area which, at least in subportions of the flow channel, can be altered by the exertion of a force on the wall element of the flow channel;

at least one actuator arranged in such a manner that it is able to exert a force on the wall element of the flow channel in a portion of the channel to reduce the cross-sectional area in the portion of the channel; and

at least one sensor arrangement for detecting a quantity of liquid medium in the portion of the channel, the sensor arrangement being located outside the flow channel.

2. The micropump according to claim 1, further comprising at least two actuators which are arranged in such a way that they are able to exert a force on the wall element of the flow channel in at least two portions of the channel, thereby temporarily closing the relevant portion of the channel and allowing a volume segment to be isolated in the flow channel, such that the sensor arrangement lying outside the flow channel can detect the quantity of liquid medium in the volume segment.

3. The micropump according to claim 2, further comprising at least two sensor arrangements for detecting the quantity of liquid medium in the at least two closable portions of the channel, the at least two sensor arrangements lying outside the flow channel.

4. The micropump according to claim 1, further comprising at least three pin-shaped actuators which are arranged next to each other outside the flow channel and which comprise at least two valve pins and at least one pump pin.

5. The micropump according to claim 1, wherein the micropump is a rotary pump with cylindrical actuators, the cylindrical actuators being arranged in a circle around a rotatable shaft, and the flow channel running in a curved course along an area adjacent to the cylindrical actuators.

6. The micropump according to claim 5, wherein the rotatable disc that rotates about an eccentric axis is employed as the actuator, the flow channel running in a near-circular course in an area adjacent to the rotatable disc or to a further disc that can be operated via the rotatable disc.

7. The micropump according to claim 1, wherein the sensor arrangement comprises an electromagnetic radiation-emitting element which is directed at an at least partially radiotransparent area of the wall element of the flow channel and in that the sensor arrangement comprises an electromagnetic radiation-detecting element which is likewise directed at an at least partially radiotransparent area of the wall element of the flow channel and which is arranged in such a way that it can detect electromagnetic radiation which has crossed the flow channel and which emerges from the area of the wall element.

8. The micropump according to claim 1, wherein the wall element has a wall area which is formed so as to be at least partially reflective and in that the electromagnetic radiation-detecting element is arranged in such a way that it can detect radiation which is emitted by the electromagnetic radiation-emitting element and reflected by the wall area.

9. The micropump according to claim 1, wherein the sensor arrangement comprises a capacitor which contains capacitor plates arranged on two sides of the portion of the flow channel, outside the wall element and in that the sensor arrangement comprises a measuring arrangement for measuring the capacitance of the capacitor.

10. The micropump according to claim 1, wherein the sensor arrangement comprises an ultrasound sensor containing an ultrasound emitter and an ultrasound receiver which are arranged on two sides of the portion of the flow channel, outside the wall element.

11. A device for metered administration of a liquid drug, comprising:

a micropump comprising;

at least one flow channel with a wall element, the flow channel having a cross-sectional area which, at least in subportions of the flow channel, can be altered by the exertion of a force on the wall element of the flow channel;

at least one actuator arranged in such a manner that it is able to exert a force on the wall element of the flow channel in a portion of the channel to reduce the cross-sectional area in the portion of the channel; and

at least one sensor arrangement for detecting a quantity of liquid medium in the portion of the channel, the sensor arrangement being located outside the flow channel;

a reservoir of the liquid drug, and

an infusion needle arrangement wherein the reservoir being connected to the infusion needle arrangement by means of the flow channel.

12. The device according to claim 11, wherein the wall element of the flow channel is detachably mounted in the micropump.

13. A method for monitoring a micropump for peristaltic pumping of a liquid medium, the micropump comprising:

at least one flow channel with a wall element, the flow channel having a cross-sectional area which, at least in subportions of the flow channel, can be altered by the exertion of a force on the wall element of the flow channel;

at least one actuator which is arranged in such a manner that it is able to exert a force on the wall element of the flow channel in a portion of the channel to reduce the cross-sectional area in the portion of the channel; and

at least one sensor arrangement located outside the flow channel detects a quantity of liquid medium in the portion of the channel.

14. The method according to claim 13, further comprising at least two actuators temporarily close two portions of the channel, thereby isolating, between the two closable portions of the channel, a volume segment, which may contain liquid medium that is to be pumped on further, and in that a sensor arrangement which lies outside the wall element of the flow channel detects the quantify of liquid medium in the volume segment.

15. The method according to claim 13, having two sensor arrangements lying outside the wall element of the flow channel detect the quantity of liquid medium in the two closable portions of the channel.

16. The method according to claim 13, wherein the at least one sensor arrangement measures absorption of electromagnetic radiation, fluorescence, or a change in capacitance in a portion of the channel.

17. The method according to claim 13, wherein the at least one sensor arrangement comprises an electromagnetic radiation-emitting element which emits electromagnetic radiation at a wavelength that is in the region of an absorption maximum of the liquid medium or at a fluorescence wavelength of the liquid medium.