Measurement Device, Measurement Tube and the Use Thereof for Monitoring of Urine Flow

Abstract

A measurement device (11) is disclosed for measurement of a flow of urine (7) in a flexible tube (4), the device (11) comprising jaws (12, 13) arranged for receiving a section of the tube (4), the device (11) further comprises an arrangement (14, 15, 6) for directing light through the tube (4) in said first direction so as to perform said measurement. A measurement tube (20) is also disclosed having a measurement area (22) within substantially parallel inner walls (23) with a distance in the range of to 4 millimetres as well as the use of the measurement tube (20) with the device (11).

Claims

1. Measurement tube (20) for a urine catheter assembly (1) having an inner cross-sectional opening with a measurement area (22) having substantially parallel inner walls (23) and a height (H1) of the measurement area (22) being the distance between said walls (23) in the range of 1 to 4 millimetres, preferably in the range of 1.3 to 2.5 millimetres.

2. Measurement tube (20) according to claim 1, wherein said measurement area (22) has an extent parallel to the inner walls (23) in the range of 4 to 12 millimetres, preferably in the range of 6 to 10 millimetres.

3. Measurement tube (20) according to claim 1 or 2, wherein the tube is made in a flexible material.

4. Measurement tube (20) according to any of claims 1 to 3, which is made from polytetrafluoroethylene (PTFE).

5. Measurement tube (20) according to any of claims 1-3, wherein the inner cross-sectional opening further comprises a flow area (24), which preferably is a substantially circular area, of an extend preferably in the range of 10 to 40 square millimetres.

6. Measurement tube (20) according to claim 5, wherein the flow area (24) is separated from the measurement area (22) by an air drain channel (25) extending in the longitudinal direction of the tube and being provided with an opening or openings (26) towards the measurement area (22).

7. Measurement device (11) for measurement of a flow of urine (7) in a measurement tube (20) according to any of claims 1 to 6, the device (11) comprising two substantially parallel jaws (12, 13) forming there between a groove for receiving a part (27) of the measurement tube (20) comprising the measurement area (22), the device (11) further comprises in one of said jaws (12) an arrangement (14, 15, 16) for directing light through said tube part (27) in a first direction substantially perpendicularly to a longitudinal direction of the tube (20) so as to perform said measurement, the device further comprising a light detector (17) in the other of said jaws (13), arranged to receive light directed through said tube part (27) by means of said arrangement (14, 15, 16).

8. Measurement device (11) according to claim 7, further comprising an optical beam expander (16) arranged to expand said light prior to being directed through said tube part (27).

9. Measurement device according to claim 8, wherein the optical beam expander (16) is arranged to expand the incoming light to a beam diameter in the range of 2.5 to 8 millimetres, preferably to a diameter in the range of 3.5 to 6 millimetres.

10. Use of a measurement device (11) according to any of claims 7 to 9 with a urine catheter assembly (1) comprising a measurement tube (20) according to any of claims 1 to 6, wherein the tube part (27) comprising the measurement area (22) is inserted between the jaws (12, 13) of the measurement device (11)

11. Use according to claim 10, where the measurement tube (20) is a flexible tube and the tube part (27) inserted between the jaws (12, 13) of the measurement device (11) is compressed so that the height (H) of the inner measurement area (22) opening in the tube part (27) is in the range of 1 to 2.5 millimetres, preferably in the range of 1.3 to 2 millimetres.

12. Use according to claim 10 or 11, wherein the measurement tube (20) is arranged so that the tube part (27) inserted between the jaws (12, 13) of the measurement device (11) is continuously filled with urine (7).

13. Measurement device (11) for measurement of a flow of urine (7) in a flexible tube (4), the device (11) comprising mutually movable jaws (12, 13) arranged for receiving a section of the tube (4) and compressing the tube (4) in a first direction substantially perpendicularly to a longitudinal direction of the tube (4), so that the height (H) of the inner opening in the tube (4) is reduced in the first direction, the device (11) further comprises in one of said jaws (12) an arrangement (14, 15, 16) for directing light through the tube (4) in said first direction so as to perform said measurement, the device further comprising a light detector (17) arranged to receive light directed through the tube (4) by means of said arrangement (14, 15, 16), wherein the light detector (17) is arranged in one of said jaws (12, 13), preferably in the other of said jaws (13).

14. Measurement device (11) according to claim 13, further comprising an optical beam expander (16) arranged to expand light prior to being directed through the tube (4).

15. Measurement device according to claim 14, wherein the optical beam expander (16) is arranged to expand the incoming light to a beam diameter in the range of 2.5 to 8 millimetres, preferably to a diameter in the range of 3.5 to 6 millimetres.

16. Use of a measurement device (11) according to any of claims 13 to 15 with a urine catheter assembly (1) comprising a flexible tube (4), where the section of the tube (4) inserted into the measurement device (11) is compressed so that the height (H) of the inner opening in the tube (4) is in the range of 1 to 2.5 millimetres, preferably in the range of 1.3 to 2 millimetres.

17. Use according to claim 16, wherein the section of the flexible tube (4) inserted into the measurement device (11) is made from polytetrafluoroethylene (PTFE).

18. Use according to claim 16 or 17, wherein the flexible tube (4) is arranged so that the section of the tube (4) compressed by the measurement device (11) is continuously filled with urine (7).

19. Use according to claim 16 or 17, wherein the flexible tube (4) is arranged so that the urine (7) will pass the measurement device (11) drop wise (10).

20. Use according to claim 19, further comprising the calculation of an estimate of the flow rate of urine (7) based on the number of drops (10) of urine (7) passing per time unit.

21. Use according to any of claims 10 to 12 or any of claims 16 to 20, wherein the measurement includes use of Raman spectroscopy.

22. Use according to any of claims 10 to 12 or to any of claims 16 to 21, wherein the measurement includes use of Near-infrared (NIR) spectroscopy.

23. Use according to claim 22, wherein said Near-infrared (NIR) spectroscopy includes the use of three to eight substantially monochromatic light sources, in particular Laser Emitting Diodes (LED).

24. Use according to any of claims 10 to 12 or to any of claims 16 to 23, wherein the measurement includes use of Mid-infrared (MIR) spectroscopy.

25. Use according to claim 24, wherein said Mid-infrared (MIR) spectroscopy includes the use of three to eight substantially monochromatic light sources, in particular Laser Emitting Diodes (LED).

26. Measurement device (11) for measurement of a flow of urine (7) in a flexible tube (4), the device (11) comprising a measurement unit having two parallel transparent panels defining a cavity and connectors for connecting the measurement unit with the tube (4), so that the flow of urine (7) through the tube (4) will pass through the measurement unit, wherein the inner perpendicular distance between the panels is in the range of 1 to 2.5 millimetres, preferably in the range of 1.3 to 2 millimetres, the device (11) further comprises an arrangement (14, 15, 16) for directing light through the measurement unit in a direction perpendicular to the panels so as to perform said measurement.

27. Measurement device (11) according to claim 26, further comprising a light detector (17) arranged to receive light directed through the measurement unit by means of said arrangement (14, 15, 16).

28. Measurement device (11) according to claim 26 or 27, further comprising an optical beam expander (16) arranged to expand light prior to being directed through the measurement unit.

29. Measurement device according to claim 28, wherein the optical beam expander (16) is arranged to expand the incoming light to a beam diameter in the range of 2.5 to 8 millimetres, preferably to a diameter in the range of 3.5 to 6 millimetres.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Examples of the present invention is illustrated in the enclosed drawing of which

[0032] FIG. 1 shows a urinary catheter assembly with drainage bag and two areas of measurement indicated,

[0033] FIG. 2 shows a detail of the first area of measurement of FIG. 1,

[0034] FIG. 3 shows a detail of the second area of measurement of FIG. 1,

[0035] FIG. 4 shows a cross-section of a flexible tube of a urinary catheter assembly arranged in a measurement clamp according to the present invention, the cross-section being made in the cross-sectional direction of the tube,

[0036] FIG. 5 shows sketch of a measurement tube for a urine catheter assembly according to a second embodiment of the present invention,

[0037] FIG. 6 shows a cross-section of one embodiment of the measurement tube of FIG. 5,

[0038] FIG. 7 shows a cross-section of a second embodiment of the measurement tube of FIG. 5, and

[0039] FIG. 8 shows a cross-section of a measurement tube FIG. 6 of a urinary catheter assembly arranged in a measurement device according to an embodiment of the present invention, the cross-section being made in the cross-sectional direction of the tube.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0040] The urinary catheter assembly 1 of FIG. 1 comprises a catheter 2 and a urine drainage bag 3 connected by means of a flexible tube 4, typically of an outer diameter of about 8 millimetre. The tube 4 is in the figure arranged so that two different areas of measurement according to different aspects of the present invention are demonstrated: a first area 5 in a downwards bend 6 of the tube 4 where a portion of urine 7 will be present continuously and a second area 8 at a substantially vertical straight section 9 of the flexible tube 4 where the urine 9 will pass drop 10 by drop 10.

[0041] The first area 5 of measurement is shown in detail in FIG. 2, whereas the second area 8 of measurement is shown in detail in FIG. 3. In the first area 5, the urine 7 from the patient will arrive drop wise 10 into the bottom of the bend 6 of the tube 4, where an amount of urine 7 will be present continuously while the urine 6 is flowing through from the catheter 2 to the drainage bag 3. Hereby, a constant output from the measurement device 11 can be provided according to the characteristics of the urine 7 contained in the bend 6. In the second area 8, the urine 7 passes drop wise 10 from the catheter 2 to the drainage bag 3 and the measurement device 11 measures the characteristics of each drop 10 of urine and provide an output accordingly. Hereby, it is possible to count the number of drops 10 of urine 7 passing and providing an estimate of the flow rate of urine 7, based on empirical data for the type and inner diameter of the flexible tube 4.

[0042] The measurement device 11 shown in FIG. 4 comprises two jaw parts 12, 13 and a support part 18 carrying the two jaw parts 12, 13 in a manner that the jaw parts 12, 13 can be moved away from each other in order to receive a piece of the flexible tube 4 between the jaws 12, 13 and towards each other to a measurement position, where the tube 4 is clamped between the jaws 12, 13 and is compressed to a flattened cross-sectional shape as shown in FIG. 4, where the height H of the inner opening of the tube 4 is about 1.5 millimetres (typically between 1 and 2 millimetres). One jaw 12 includes a connector 14 for connecting an optical fibre cable 15 to the jaw 12 and an optical beam expander 16 arranged so that the light transmitted from the optical fibre cable 15 is expanded to have a diameter of 3 to 6 millimetres when passing the measurement area 5, 8 of the tube 4. On the opposite jaw 13 is a light detector 17 arranged for detection of light from the optical beam expander 16 transmitted through the measurement area 5, 8 of the tube 4.

[0043] By compressing the piece of flexible tube 4 between the jaws 12, 13 a sufficiently short optical pathway through the possible urine 7 inside the tube 4 for the light from the optical beam expander 16 and to the light detector 17 that an acceptable signal to noise ratio is obtained. The signal from the light detector 17 is transmitted to a signal processor (not shown) with a signal cable 19.

[0044] The optical fibre cable 15 is connected to a light source box (not shown) that contains the laser source for Raman spectroscopy of the urine 6 in the measurement area 5, 7 in a forward-scatter configuration as well as the monochromatic light emitters, in particular Light Emitting Diodes (LED) employed for spectroscopy in particular in the Near Infrared (NIR) area, defined as infrared light of wavelengths between 800 nm and 2,500 nm or the Mid Infrared (MIR) area, defined as infrared light of wavelengths between 2,500 nm and 20,000 nm. In a particular embodiment of the present invention, the Raman spectroscopy is arranged in a back-scattering arrangement, and a suitable detection system for the back-scatter is placed in the light source box. By combining the use of Raman spectroscopy and NIR or MIR spectroscopy, the error margin of the measurement device 11 can be substantially reduced.

[0045] Such an apparatus for the analysis of constituents in the urine makes possible a simple and cost-effective possibility of establishing a continuous monitoring of persons with a catheter connected to their bladders. By the analysis, the function of the kidneys may be examined, for example by measuring the content of carbamide, creatinine, sodium ions and/or potassium in urine. Similarly, examination may be of content of albumine, glucose, nitrogen and/or oxygen to investigate other functions of the body, or whether the urine contains myoglobin, blood or glucose, which may be indicative of various disease states. By this simple and inexpensive solution it is achieved that analysis of urine can be done to a greater extent where the patient is located, for example in his home, and a doctor, or other health professional staffing, can at once obtain a measurement result and initiate treatment or other measures as a result.

[0046] A measurement tube 20 according to the present invention is shown in FIGS. 5, 6 and 7, where FIG. 5 is a sketch of a side view of the measurement tube 20 connected to a flexible tube 4 at both ends by means of adapter tube pieces 21 that provides the transition between the substantially circular outer cross-sectional shape of the flexible tubes 4 and the outer keyhole-shape of the measurement tube 20. The cross-sectional shape of the inner opening 22, 24 is indicated on the measurement tube.

[0047] The cross-sectional shape of a first embodiment of the measurement tube 20 is shown in FIG. 6, having an inner measurement area opening 22 of a width H1 of about 2 millimetres between substantially parallel inner walls 23 and a flow area 24 of substantially circular cross-sectional shape. The tube part comprising the measurement area 22 is generally referred to with reference number 27. The measurement tube 20 is made in a flexible and transparent material, preferably in polytetrafluoroethylene. The flow area 24 is provided to ensure that the full flow of urine 7 from the patient will be able to pass through the measurement tube, whereas the measurement area opening 22 is provided for allowing optical measurement of the characteristics of the urine as discussed previously through the tube part 27 comprising the measurement area 22.

[0048] The cross-sectional shape of a second embodiment of the measurement tube 20 is shown in FIG. 7, which deviates from the first embodiment shown in FIG. 6 in that an air drain channel 25 is provided, which is connected to the measurement area opening 22 by means of one or more openings 26 provided there between. The opening or openings 26 may either be a continuous slit extending the full length of the measurement tube 20 or it may comprise a plurality of separate openings 26 with e.g. 10 to 15 millimetres separation in the longitudinal direction of the measurement tube 20. The air drain channel 25 is typically closed at the end of the measurement tube 20 connected to the catheter side of a catheter assembly and is open at the opposite end. The measurement area opening 22 as well as the flow area 24 are open at both ends of the measurement tube 20, thus allowing urine 7 to flow through both areas 22, 24. The air drain channel 25 ensures that air trapped inside the measurement area 22, in particular when the assembly is taken into use, will be drained out and allow a flow of urine 7 in the measurement area 22.

[0049] A modified version of the measurement device 11 of FIG. 4 designed to receive the measurement tube 20 of FIGS. 5 to 7 is shown in FIG. 8. The two jaws 12, 13 are of a cross-sectional shape and mutual distance to form a groove there between for receiving at least a part of the tube part 27 comprising the measurement area 22 so that light from the optical fibre cable 15 can be transmitted through the urine 7 in the measurement area 22 to the light detector 17. The jaws 12, 13 may either be of a fixed mutual distance, so that the tube part 27 may be manually pushed into the groove, or the distance between the jaws 12, 13 may be adjustable so that the tube part 27 is first inserted between the jaws 12, 13 and then compressed by moving the jaws 12, 13 towards each other. The device 11 is oriented so that the tube part 27 containing the measurement area 22 is downwards in order to ensure that it is filled with urine even in situations where the whole inner opening 22, 24 is not, as indicated in FIG. 8, where only the lower half of the circular flow area 24 is filled with urine.

REFERENCES

[0050] 1 Urine catheter assembly [0051] 2 Catheter [0052] 3 Urine drainage bag [0053] 4 Flexible tube [0054] 5 First measurement area [0055] 6 Downwards bend of the tube [0056] 7 Urine [0057] 8 Second measurement area [0058] 9 Straight section of the tube [0059] 10 Urine drop [0060] 11 Measurement device [0061] 12 First jaw of device [0062] 13 Second jaw of device [0063] 14 Connector [0064] 15 Optical fibre cable [0065] 16 Optical beam expander [0066] 17 Light detector [0067] 18 Support part [0068] 19 Signal cable [0069] 20 Flexible measurement tube [0070] 21 Adapter tube piece [0071] 22 Measurement area opening [0072] 23 Inner walls of measurement area [0073] 24 Circular flow area opening of measurement tube [0074] 25 Air drain channel [0075] 26 Opening between air drain channel and measurement area opening [0076] 27 Tube part comprising the measurement area [0077] H Inner height of cross-sectional opening in tube compressed in measurement device [0078] H1 Inner height of cross-sectional measurement area opening in measurement tube