METHOD AND DEVICE FOR IDENTIFYING A CHANGE IN PRESSURE IN THE LIQUID PATH OF A MICRODOSING DEVICE

• US 20090118667A1
• Filed: 08/12/2008
• Published: 05/07/2009
• Est. Priority Date: 02/13/2006
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics International AG (Roche Holding AG)
• Inventors: Bosshard, David, Haueter, Ueli, Heutschi, Ivan, Rufer, Thomas, Stoller, Hanspeter
• Granted Patent: US 8,081,069 B2
• Time in Patent Office: Days
• US Class Current: 604/67
• CPC Class Codes: A61M 2005/16868 Downstream occlusion sensors
• CPC Class Codes: A61M 2205/3306 Optical measuring means
• CPC Class Codes: A61M 2205/3355 Controlling downstream pump pressure
• CPC Class Codes: A61M 2205/3375 Acoustical, e.g. ultrasonic, measuring means
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/16854 by monitoring line pressure
• CPC Class Codes: G01L 9/0077 for measuring reflected light

Abstract

An insulin pump and an infusion set adapter having a membrane which can be acted upon by a liquid flow path associated with the pump, wherein the pump comprises a sensor by which a change in shape or location of at least a portion of the membrane caused by a change in the liquid pressure in the flow path can be detected in a contact-free manner to identify an occlusion in the flow path.

Claims

1. An insulin pump and an infusion set adapter having a membrane which can be acted upon by a liquid flow path associated with the pump, wherein the pump comprises a sensor by which a change in shape or location of at least a portion of the membrane caused by a change in the liquid pressure in the flow path can be detected in a contact-free manner to identify an occlusion in the flow path.

2. A method for identifying a change in pressure in a liquid in a liquid flow path associated with a microdosing device for delivering a liquid substance, the method comprising the steps of:

a) providing a structure configured and operatively connected to the liquid substance in the liquid flow path such that the structure changes shape when a pressure of the liquid changes, and

b) using a sensor to detect the change in shape without contacting the structure.

3. A method for identifying a change in pressure in the liquid path of a microdosing device for dosing liquid substances, the method comprising the following steps:

a) providing a physical entity which is configured and is operatively connected to the liquid guided in the liquid path in such a manner that it undergoes a change in form when the pressure of the liquid guided in the liquid path changes, and

b) detecting the change in form of the physical entity by using contact-free measuring means for the purpose of identifying the change in pressure.

4. The method according to claim 3, wherein the physical entity is changed at least once while the measuring means is retained.

5. The method according to claim 4, wherein, after each change of form of the physical entity, the form thereof is determined in one of an unpressurized operating state or an operating state free from negative pressure, and then the relative change in form in comparison to said determined form is detected to identify the change in pressure.

6. The method according to claim 3, wherein the physical entity is coupled to one of a bypass of the liquid path or a blind channel communicating with the liquid path for being operatively connected to the liquid in the liquid path.

7. The method according to claim 3, wherein the physical entity comprises one of an elastic tube section or an elastic bubble-like body, and an expansion or shrinkage the tube section or the bubble-like body is detected by the measuring means.

8. The method according to claim 3, wherein the physical entity comprises a membrane and an increasing or decreasing bulging of a surface of the membrane, acted upon on one side by the liquid, is detected by the measuring means.

9. The method according to claim 3, wherein the physical entity comprises a component acted on by the liquid, and one of a displacement, rotation or inclination of the component is detected by the measuring means.

10. The method according to claim 3, wherein, to detect the change in form, a distance or a change in a distance is measured by one of an optical, acoustic, inductive or capacitive distance-measuring means.

11. The method according to claim 3, wherein the physical entity comprises a surface for receiving and reflecting a light beam, and wherein, when the physical entity changes form the light beam shifts or is deformed, the reflected light beam being received by one of a spot-type, linear or X-Y photosensor.

12. The method according to claim 3, wherein, in order to detect the change in form, the physical entity has a contour that changes when there is a change in pressure, the contour providing a shadow thrown onto one of a spot-type, linear or X-Y photosensitive sensor.

13. The method according to claim 3, wherein the physical entity comprises elements arranged in one of a line pattern or lattice grid on a surface thereof, and wherein, to detect the change in form, the distance or change in distance between the elements is determined by a camera comprising an electronic evaluation system.

14. The method according to claim 3, wherein the detection of the change in form takes place continuously, at intervals or in an event-driven manner.

15. The method according to claim 3, wherein a detected change in form or a pressure value derived from said change in form is compared by an electronic evaluation system with at least one specified value and, when the specified value is exceeded or fallen short of, at least one of an acoustic, optical and tactile alarm is triggered.

16. The method according to claim 3, wherein a detected change in form or a pressure value derived therefrom is adjusted before being comparison with a specified value by using an adjustment algorithm to correct the effect of one or more of ambient air pressure, ambient temperature, vibration and mechanical deviations in position between the physical entity and the measuring means.

17. The method according to claim 3, said method being used to identify an occlusion in the liquid path of the microdosing device.

18. A device for identifying a change in pressure in a liquid in a liquid flow path associated with a microdosing device for delivering a liquid substance, the device comprising:

a) a structure comprising a liquid-tight interior space operably connected via at least one opening to the flow path, wherein at least a portion of the structure changes shape if the pressure of the liquid in the flow path changes during operation of the microdosing device, and

b) a sensor operably coupled to the structure such that a change in shape is detected in a contact-free manner.

19. A device for identifying a change in pressure in a liquid in a liquid flow path associated with a microdosing device for delivering a liquid substance, the device comprising:

a) a physical entity with a liquid-tight interior space which is connected or can be connected via at least one opening to the liquid path, wherein the physical entity is configured such that it undergoes a change in form when the pressure of the liquid in the liquid path changes during operational changes of the microdosing device, and

b) measuring means configured and coupled to the physical entity such that a change in form of the physical entity is detected in a contact-free manner.

20. The device according to claim 19, wherein the interior space forms one of a part of the liquid path, a bypass line coupled to the liquid path or at least part of a blind channel communicating with the liquid path.

21. The device according to claim 19, wherein the device is configured such that a tool-free changing of the physical entity is possible, said measuring means remaining on the device.

22. The device according to claim 19, wherein the physical entity comprises one of an elastic tube section or an elastic bubble-like body which undergoes an expansion or shrinkage when the pressure of the liquid located in the tube section or body changes.

23. The device according to claim 19, wherein the physical entity comprises a membrane which bulges to a greater or lesser extent when the pressure of the liquid changes.

24. The device according to claim 23, wherein the membrane either has a reflective region or supports a rigid reflector, the change in shape or position of which as a consequence of a change in pressure of the liquid can be detected by reflection of a light beam on the same by the measuring means.

25. The device according to claim 23, wherein the membrane is acted upon or can be acted upon on one of its two sides directly by the liquid.

26. The device according to claim 25, wherein the membrane comprises a contact surface for contacting the liquid, the contact surface comprising one of notches, ribs or a pyramid pattern.

27. The device according to claim 19, wherein the physical entity comprises a rigid component which is displaced, rotated or inclined with respect to another element of the physical entity when the pressure of the liquid located in its interior space changes.

28. The device according to claim 27, wherein the physical entity comprises a piston-cylinder arrangement comprising a spring-force-loaded piston which undergoes a displacement in the cylinder when the liquid pressure changes.

29. The device according to claim 27, wherein the physical entity comprises one of a piston- or plate-shaped element guided displaceably by a bead-shaped component and undergoing a displacement or inclination when the liquid pressure changes.

30. The device according claim 28, wherein the piston or the piston- or plate-shaped element is acted upon or can be acted upon on one side directly by the liquid.

31. The device according claim 29, wherein the piston or the piston- or plate-shaped element is acted upon or can be acted upon on one side directly by the liquid.

32. The device according to claim 19, wherein the measuring means is configured to detect a distance or change in distance between a surface of the physical entity, which surface changes when there is a change in pressure, in relation to a reference surface, and wherein said measuring means provides one of an optical, acoustic, inductive or capacitive distance measurement.

33. The device according to claim 19, wherein the measuring means is configured to detect a change in position or shape of a surface of the physical entity, which surface one of shifts and/or is deformed when there is a change in pressure, by reflection of a light beam on the shifting or deforming surface onto one of a photosensitive spot-type, linear or X-Y sensor.

34. The device according to claim 33, wherein the membrane has a reflective region or supports a rigid reflector, the change in shape or position of which as a consequence of a change in pressure of the liquid can be detected by the reflection of a light beam on said region or reflector by the measuring means.

35. The device according to claim 34, wherein the region of the membrane which surrounds the reflective region has a satin finish.

36. The device according to claim 34, wherein the physical entity and the membrane are made from a light-impermeable material.

38. The device according to claim 19, wherein the measuring means is configured to detect a projected surface of at least part of the physical entity or a change in the projected surface of at least part of the physical entity in a certain direction as a consequence of a change in pressure of the liquid by projection of a shadow image of at least part of the physical entity onto one of a photosensitive spot-type, linear or X-Y sensor by a light source.

39. The device according to claim 19, wherein the physical entity comprises a surface which expands or shrinks when there is a change in pressure of the liquid in the liquid path, a plurality of elements arranged one the surface and spaced apart from one another in one of a line pattern or lattice grid which expands or shrinks together with said surface, and wherein the measuring means is configured to detect the distance or the change in the distance between the elements and comprises a camera comprising an electronic evaluation system.

40. The device according to claim 19, wherein the measuring means is configured to detect the change in form continuously, at intervals or in an event-driven manner.

41. The device according to claim 19, wherein the device comprises an electronic evaluation system with which a detected change in form or a pressure value which can be derived from said change in form can be compared with at least one user-programmable specified value and, when the specified value is exceeded or fallen short of, at least one of an acoustical, optical or by tactile alarm is triggered.

42. The device according to claim 19, wherein the device comprises an electronic evaluation system with which a detected change in form or a pressure value derived therefrom can be corrected before the comparison with a specified value, by a correction algorithm to correct for the effect of certain disturbance variables, said variables including one of more of ambient air pressure, ambient temperature, vibration, and mechanical deviations in position between the physical entity and the measuring means.

43. The device according to claim 19, wherein the device is one of an independent functional unit or is integrated in the microdosing device.

44. The device according to claim 43, wherein the device is used in conjunction with dispensing one of liquid medicaments or insulin.

45. A microdosing device for the temporally controlled dispensing of liquid medicaments, the microdosing device comprising a component device for identifying a change in pressure in a liquid in a liquid flow path associated with the microdosing device, the component device comprising:

a) a physical entity with a liquid-tight interior space which is connected or can be connected via at least one opening to the liquid path, wherein the physical entity is configured such that it undergoes a change in form when the pressure of the liquid in the liquid path changes during operational changes of the microdosing device, and

b) measuring means configured and coupled to the physical entity such that a change in form of the physical entity can be detected in a contact-free manner, wherein

c) the physical entity is a changeable part which can be interchanged without using a tool and the measuring means is arranged on the microdosing device such that it cannot be removed without using a tool.

46. The microdosing device according to claim 45, wherein the measuring means is integrated in the pump housing for multiple use, and the physical entity, intended for a single use, is part of an infusion set adapter or an infusion set.