WO2022009223A1

WO2022009223A1 - System and method for monitoring urine output

Info

Publication number: WO2022009223A1
Application number: PCT/IN2021/050655
Authority: WO
Inventors: Dilip SHANKAR; Shankar RAMAIAH
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-07-05
Filing date: 2021-07-05
Publication date: 2022-01-13
Anticipated expiration: 2023-01-05

Abstract

The invention relates to a system and method for accurately monitoring of urine output (UO) in a catheterized patient. The system comprises a human-machine interface (HMI) station that is provided with integration of modules such as diagnostics, visualization and alerting, and communication and control. The method comprises actively clearing a urine line system by use of a negative pressure in the catheter system facilitating removal of residual urine and enabling accurate measurement of UO. The method further comprises obtaining values of urine parameters to enable early diagnosis and staging of acute kidney injury (AKI).

Description

TITLE OF THE INVENTION: SYSTEM AND METHOD FOR

MONITORING URINE OUTPUT PREAMBLE OF THE DESCRIPTION: The following complete specification particularly describes the invention and the manner in which it is performed. FIELD OF INVENTION:

The present invention relates to the field of medical devices, in particular systems and methods for early detection of kidney dysfunction in patients based on real time monitoring and diagnostics of urinary parameters from a catheterized patient. BACKGROUND OF THE INVENTION

The kidney helps to eliminate liquid waste (urine) by storing urine in the bladder and the bladder eliminating the urine through the urethra. Patients with bladder management issues are typically provided with urinary catheters (such as a Foley Catheter) to manage bladder dysfunction. A typical urinary catheter can be inserted into the urethra and advanced into the bladder allowing for the continuous, passive drainage of urine from the bladder. The urine drained from the bladder flows through a flexible catheter tubing and is collected into a disposal urine bag. Many diagnostic of the kidney can be performed by measuring various urinary parameters as the urine passes along the flexible catheter tube and gets collected in the disposal bag. Such urinary parameters could comprise of the urine output, urine conductivity, urinary oxygen tension, and specific gravity.

The urine output is one of the key relevant biological markers for early diagnosis and staging of acute kidney injury (AKI). A widespread clinical practice for urine output (UO) measurement involves manually recording of UO parameters such as urine volume and flow rate in a pre-determined time period. Such traditional methods for measuring UO are often inaccurate owing to multiple reasons comprising the manual error in the task for recording urine volume over a period of time; errors in time period measurement associated with real-time minute-to- minute variability in urine output that tends to occur at irregular intervals.

In addition to such human errors, inaccuracies in the measurements of UO are also contributed by incomplete urinary drainage due to urinary retention in the bladder and the catheter tube. This is referred to herein as residual urine. Kinks or loops in the flexible catheter tubes can cause airlocks within the catheter tube at various locations in the catheter tube leading to impediments in the flow of urine causing urine retention within the bladder and/or the catheter tube. Use of excess drainage tubing in a urine drainage system (commonly referred to as dependent loops) is also known to trap or retain urine and contribute to the residual urine.

Any UO measurement performed under such conditions where the residual urine does not get accounted for will result in inaccurate data associated with UO monitoring. Consequences of such inaccurate UO measurements include reporting of false oliguria and false anuria in a urine monitoring period leading to inadvertent patient mismanagement.

Conventional method being widely used, have further complications and errors which rise due to human error while measuring. So, always manual urine flow measurements have been unreliable. Manual urine flow measurements are time taking which needs visual assessment during data recording onto log books. Manual recording also leads to cumulative errors during recording which may be due to poor quality of volume containers and markers on urine bags. There are several scenarios where patient develops conditions like oliguria and there is no standard procedure to detect it using manual methods. So, manual methods questions about reliability of urine bag reading, in terms of accuracy, regularity and frequency while recording.

The aforementioned process of UO measurement is thus subjective, time consuming and prone to error. Further, in some scenarios, the clinical practice personnel may lack the knowledge to process the UO parameters for taking necessary action against values of the UO parameters breaching an acceptable pre defined threshold. Hence, there is a need for a method and a system that can automatically and accurately extract the UO parameters by also accounting for the residual urine and generate alert signals against threshold breach of the UO parameters for actionable intervention. The present invention overcomes the problems of prior art by providing a device and means for actively clearing the urine line system by use of negative pressure in the catheter tube thereby facilitating removal of residual urine and enabling accurate measurement of UO. The UO measurements correlate with kidney function. The invention thus provides a real-time accurate measurement of oliguria and also enables early diagnosis and staging of acute kidney injury (AKI). The invention also provides a device and a method for integration of additional measurement devices that monitor different parameters and conditions such as density, hydration status, hypovolemia, and hypovolemic shock.

SUMMARY OF THE INVENTION In view of the foregoing a urine output monitoring apparatus (400) including a load cell (410), a microcontroller (413) and a processor (414). The load cell (410) further comprising a force transducer configured to convert the weight of a urine bag (416) into an electrical signal and the micro-controller (413) is configured to calculate the weight of a urine bag (416) upon receiving the electrical signal and the processor (414) is configured to analyze the measured weight of the urine bag (416) for indicating risk of at least a disease.

A vacuum box (310) configured to suck the urine sample from the urine catheter tube (110) and thereby accurately clearing the urine from the urine catheter tube (110). The apparatus (400) further comprises a tablet holder (402) configured to receive a display unit for displaying the monitored weight of the urine bag (416). The apparatus (400) is configured to share the analyzed weight of the urine bag (416) to hospital authorities. The apparatus (400) is configured to provide alerts such as tube placement alerts and tilt alerts. The apparatus (400) is configured to alert the hospital authorities when the analyzed weight of the urine bag (416) breaches the pre determined weight value. A base (408) of the apparatus (400) further comprising castor wheels to displace the apparatus (400) from one position to another. In an aspect a method for analyzing urine output by hanging a urine bag (416) to a hook of an apparatus (400) and converting the weight of the urine bag (416) into electrical signals by a transducer. The weight of the urine bag (416) is calculated by a micro-controller (413) and analyzing the weight of the urine bag (416) by a processor (414).

In the aspect, the apparatus (400) is configured to share the analyzed weight of the urine bag (416) to hospital authorities. The apparatus (400) further comprises a vacuum box (310) configured to suck the urine sample from the urine catheter tube (110) and thereby accurately clearing the urine from the urine catheter tube (110).

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be described in even greater detail below based on the exemplary figures. It is to be noted, however, that the exemplary figures illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope.

The figures are not drawn to scale and the proportions of certain parts have been exaggerated for convenience of illustration. Further, in the accompanying drawings and description that follow, like parts are indicated throughout the drawings and written description with the same reference numerals.

FIG. 1 is a simplified view of a typical catheter system in which various embodiments of the present invention can be practiced.

FIG. 2a shows a block diagram of a system for a human-machine interface (HMI) station and its communicatively coupled devices, according to an embodiment of the present invention.

Figs. 3 show an embodiment of the active drain line clearing mechanism adapted with the catheter system that uses a negative pressure induced by a vacuum box. Fig. 4a illustrates an isometric view of a urine output monitoring apparatus (400); and Fig. 4b illustrates an exploded view of a casing (404) of the urine monitoring apparatus (400).

DETAILED DESCRIPTION OF THE INVENTION The present invention overcomes the problems of prior art, as mentioned above, by providing a means for actively clearing the urine line system by use of negative pressure in the catheter tube thereby facilitating removal of residual urine and enabling accurate measurement of UO. The invention thus provides an accurate measurement of oliguria and also enables early diagnosis and staging of acute kidney injury (AKI).

The present invention is related with a device and a method to enable accurate monitoring of UO, visual display of the UO and few key measured urine parameters, and using an alerting system to alert clinical personnel on the parameters of the urine and / or condition of the patient. Various embodiments of the present invention can be practiced in an environment such as environment 100 shown in FIG. 1.

A typical catheter system is illustrated schematically in FIG. 1. The catheter system 100 is provided with a tip (also referred to as the catheter tip) 105 that may be inserted into a patient's bladder to facilitate drainage of urine collected in the bladder. A small retention balloon 105a is provided close to the catheter tip 105 wherein the retention balloon 105a can be inflated with a fluid (typically sterile water) to prevent the catheter from sliding out of the bladder. The retention balloon 105a can be deflated when the catheter needs to be removed. The urine collected by the catheter tip 105 flows down along a hollow, flexible catheter tube 110 to eventually be collected in a drainage urine bag 150. The catheter system

100 may be adapted to have two-lumens 115, 115a wherein one of the lumens 115a (also referred to as balloon inflation lumen) has a valve on the outside end and connects to the retention balloon 105a near the catheter tip 105. This balloon inflation lumen 115a is configured for inflating or deflating the retention balloon 105a. The other lumen 115 (also referred to as fluid drainage lumen) is open at both ends and allows for urine drainage from the urinary bladder by connection to a drainage urine bag 150 through further use of catheter tube 110 as may be necessary.

The catheter system 100 may include a human-machine interface (HMI) station 140 that is configured for data logging, display, and alert generation. The HMI station 140 could also be adapted to comprise diagnostic and control devices such vacuum pumps, urine sample analysis devices, and the like. Furthermore, the HMI station 140 is provided with storage, processing, and communication capabilities and is further elaborated upon in the discussion with reference to FIGs. 2a and 2b. FIG. 2 shows a block diagram of the HMI station system 200 for the HMI station 140 and its communicatively coupled devices, according to an embodiment of the present invention. The HMI station system 200 may also include a plurality of devices for monitoring of various urinary parameters such as specific gravity or density, conductance, flow rate, pH, temperature, etc. Based on such urinary parameters, the HMI station system 200 may also estimate and assess, using known methods, the condition of the patient wherein the condition assessment could comprise of hydration status, hypovolemia, hypovolemic shock, renal perfusion, AKI staging, and episodes of oliguria. The monitored urinary parameters and estimated patient condition could be displayed on a visualization window provided with the HMI station 140.

The mentioned plurality of devices for monitoring of various urinary parameters could include spectrophotometers 140c for urine composition analysis, non- invasive urine density measurement device, artificial intelligence (AI) camera modules for automated analysis and recording of urine dipstick test, optical drop detector system to measure urine flow rate and volume by counting the number of drops of urine produced by the patient, etc.

In an embodiment, the apparatus (400) measures urinary output by ultrasonic based density process.

In an embodiment, the volume of the urinary output is measured by dividing mass to the density of the urinary output. The volume of the apparatus (400) may also be measured by calculating the specified gravity of the urinary output and multiplying the same to the weight of the urinary output.

In a preferred embodiment of the invention, the traditional catheter system could be engineered to enable attaching a novel device 120 to the catheter for incorporating array of diagnostic and control tools that may not already be part of the traditional catheter system 100. The channel or port 120a on the novel device 120 could be adapted for including a fiber-optic probe 135 that supplements the spectrophotometer 140c. The other port 120b is open at both ends and allows for urine drainage from the urinary bladder by connection to a drainage urine bag 150 through further use of catheter tube 110 as may be necessary.

With further reference to FIG. 2, the HMI station 140 is provided with storage, processing, and communication capabilities to enable it to store the data corresponding to the urinary parameters measured by the array of diagnostic devices mentioned above. These diagnostics devices are communicatively connected with the HMI station 140 to enable such a data transfer from the diagnostic devices to the HMI station 140.

The HMI station 140 may be further configured to display a graphical and textual visualization of pre-defined urinary parameters such as pH, specific gravity, conductivity, etc. The HMI station 140 can also generate alarms through the provided alerting units 140a. The alarms could be audible and / or visual signal that draws the attention of clinical personnel towards one or more urinary parameters that may be breaching a clinically pre-defined acceptable range.

The HMI station 140 may also be configured to have an operator 220 such as a clinical personnel manually interface with the HMI station 140 for read, write and / or administrator related tasks. The administrator tasks could involve setting user privileges and authorizations for login and data access on the HMI station 140. The read task could involve the operator 220 or an authorized clinical personnel downloading data from the HMI station 140 to another external device that is capable of being interfaced with the HMI station 140. Such external device could be a local storage or computational device including a local server, data card, a local computer, etc. The write task could involve updating key information such as re-defining acceptable range for diagnostic parameters, adding physician notes on the device, editing the list of parameters for graphical visualization, etc.

The HMI station 140 may also be communicatively connected through a gateway 230 with an external server 240 such a cloud computing and storage server or / and an edge computing and storage server. The external server 240 may additionally be configured to have storage, computational processing, and visualization capabilities. The storage capability could be used for storing and archiving patient information in the form of electronic medical records (EMRs). All the communication interfaces 210a, 210b, 210c may be provided through wired or wireless communication technologies using different communication protocols (such as TCP/IP).

The external server could also host software tools for performing computational processing on the saved and archived data. The computational processing could comprise of time-series analysis and anomaly detection, implementing machine learning algorithms to extract trends in data that could help detection of patient conditions such as urinary tract infection (UTI), and urinary composition recognition using AI camera modules and other diagnostic data. The thus computationally processed data could also be visualized with the visualization features provided on the external server 240.

Additionally (not shown in the figure), the external server 240 may be communicatively connected with a plurality of authorized processing devices such as smartphones, laptops, etc., belonging to the patient or other clinical personnel, either through a web interface or through an application program (app). This allows patients and other clinical personnel to access the medical records with ease. This also allows the clinical personnel to collaborate across geographical regions for improved data assessment and clinical prognostics.

In an embodiment, the HMI station system 200 includes a number of control devices such as vacuum devices for urine line clearance system for removal of airlocks and other potentially retained residual urine in either the bladder or in the intervening catheter system components (such as the flexible tubes). Further details on the active drain line clearing system 285 are discussed with reference to FIG. 3. The active drain line clearing system 285 uses a vacuum pump or a suction motor (such as a peristaltic pump, a piston pump, a gear pump, or a diaphragm pump) to induce a negative pressure in the catheter system to enable draining residual urine. In a preferred embodiment of the invention, the HMI station 140 is provided with a microcontroller 245 that is central to communication between the HMI station 140 and the active drain line clearing system 285.

As was mentioned earlier, the traditional catheter system could be engineered to enable attaching a novel device 120 to the catheter for incorporating array of diagnostic and control tools that may not already be part of the traditional catheter system 100 - one of the control devices that may be provided to the catheter system 100 is a vacuum pump device. FIG. 3 show an embodiment of a vacuum based urine line clearance system 300 that uses a vacuum induced at the end of the drainage line to ensure any urine retained in the bladder or the catheter system gets drained and collected in the drainage urine bag 150. The vacuum is first induced into a vacuum box 310 provided with the vacuum based urine line clearance system 300. A means is also provided for initiating this vacuum through a vacuum pump or a suction motor 330. In a preferred embodiment of the invention, the suction motor 330 is electrically powered. In another embodiment of the invention, the suction motor could be mechanically powered.

The vacuum thus induced in the vacuum box 310 leads to building of negative pressure at the catheter tube 110 that inlets urine into the vaccum box 310 through a channel provided in the vacuum box. Such a negative pressure applied towards the end of the catheter drain line facilitates more complete drainage of the bladder and avoids the urine retention in the bladder. The vacuum based urine line clearance system 300 is also provided with pressure regulators (not shown) to regulate the magnitude of the vacuum pressure induced in the catheter system. In one embodiment of the invention, the vacuum based urine line clearance system 300 could be integrated with the HMI station 140 for a fully self-contained system for accurate draining and measurement of urinary output.

In another embodiment of the invention, the vacuum based urine line clearance system 300 could be externally interfaced with the HMI station 140 and different mechanism could be adopted for vacuum sources through means that are well known.

The suction motor 330 is attached to the vacuum box 310 through a leak proof connector 320 mechanism such as a luer lock. The negative pressure applied could either be intermittent such as being periodically applied or it could be constantly applied. Alternately, the applied negative pressure could be adaptive based on historical time-series data as analyzed for a given patient, and made available through data retrieved from HMI station 140 or / and the external server 240. Such application of negative pressure is well suited to facilitate drainage of any retained urine in the bladder or / and the traditional catheter system. This vacuum assisted urine drain passes through the vacuum box 310 and into a chamber 340 provided with the vacuum box 310. The chamber 340 has an outlet 360 that leads the drained urine into the drainage urine bag 150. The chamber 340 is provided with sensor devices 350 for accurately measuring the urinary output (UO). In one embodiment of the invention, the sensor device 350 may be a capacitive strip device that measures and reports the real-time level of the accumulated urine droplets. Data from the sensor device 350 may be logged into the storage modules of HMI station 140 through use of appropriate communication method and protocols. In another embodiment of the invention, the sensor devices 350 may be communicatively connected with the external server 240 to facilitate transfer of data from the sensor devices 350 to the external server 240 through the provided gateway 230. Thus a real-time monitoring and reporting of the accurate urinary output (UO) is accomplished and potential false oliguria and false anuria periods in the UO are eliminated by ensuring appropriate draining of any retained urine in the bladder or the catheter system. Fig. 4a illustrates a urine output monitoring apparatus (400) for urine measurement. The apparatus (400) enables electronically based measurements for urine output in real time. The apparatus (400) includes a tablet holder (402), a casing (404), a stand (406) and a base (408).

Fig. 4b illustrates an exploded view of the casing (404) of the output monitoring apparatus (400).

In an embodiment, the base (408) includes castor wheels to displace the apparatus (400) from one position to another. The casing (404) further includes a load cell (410), a processor (414) and a microcontroller (413).

The apparatus (400) is configured to measure the weight of a urine bag (416) that is hung on a hook of the apparatus (400). The apparatus (400) is configured to measure the weight of the urine bag (416) in real time. The load cell (410) of the apparatus includes a force transducer that is adapted to convert the mechanical tension applied on the hook of the apparatus into electronic signals. The electronic signal corresponds to the real time weight measurements of the urine bag (416). The microcontroller (413) is configured to receive the electronic signals converted by the force transducer of the load cell (410). The microcontroller (413) is configured to calculate the weight of the urine contained inside the urine bag (416) by keeping the weight of the urine bag (416) aside.

The calculation part of the weight of the urine bag (416) includes an algorithm. The algorithm is configured to calculate the weight of the empty urine bag (416). Upon receiving the urine sample inside the urine bag (416), the algorithm again configured to calculate the weight of the urine bag (416) that is at other duration of the time.

For instance, the microcontroller (414) calculates the weight U1 of the urine bag (416) at time Tl, that is the urine bag (416) is empty. The microcontroller (414) again calculates the weight U2 of the urine bag (416) at time T2 that is the urine bag (416) contains some amount of urine the weight of urine bag then, TTotal

U_Total — U₂ — Ui Where, T_Total is the time elapsed between two-time stamps.

U_Totai is the total Urine collected in the urine bag.

The calculation requires the amount of urine collected in the urine bag (416), on observing the change in volume after certain time interval. The change in total volume will be the change in urine volume collected. Here the working principle is to measure the volume of the urine collected and then representing it in the form of ml (liquid unit). The output of the microcontroller (413) is based on the considerations including the specific gravity and the accurate volume measured at the bag, therefore: enabling a unique allocation for the urine bag (416) to a particular patient. The microcontroller (416) of the apparatus (400) is configured to clear the unique ID’s and update the unique ID’s according to the requirements. The urine bag (416) is provided with unique identification card that sticked on to the tube of the urine bag (416). The apparatus (400) includes a reader that is configured to read the unique ID of the urine bag (416). This is executed to keep the record of total urine volume generated by patient, even if multiple urine bags have been changed.

The processor (414) is configured to process or analyze the weight calculated by the micro-controller (413). The output of processor (414) indicates the risk of cardio-vascular disease (CVD), kidney disease or any other disease based on the measured weight of the urine bag (416).

The tablet holder (402) is configured to receive a tablet or any other display device. The tablet is configured to display the output of the apparatus (400). The output can be accessed on a dedicated android display, where one can have the visual analysis of urine output of the patient on real time for a period of maximum 48 hours. The data can be further shared and deployed to hospitals EMR facility. This android application is having the features to validate the urine output on hourly, six-hour, twelve hour and twenty-four-hour bases, the differentiation here is the computation done with the software and the data received on real time. The algorithm is implemented to monitor the risk assessment which works under the KDIGO guidelines and will be shown along with the reports and time based analysis of urine output.

The vacuum box (310) therefore ensures nearly zero reluctance for the urine flow in the catheter tube (110) and thus eliminates the hampering in calculation of weight of the urine bag (416) by the apparatus (400). In an embodiment, the urine output monitoring apparatus (400) is configured to alert the hospital authorities when the analyzed weight of the urine bag (416) breaches the pre-determined weight value.

In an embodiment, the apparatus (400) is configured to monitor the plots and data from outside of the ICU. The apparatus (400) is adapted to deploy adjacent to a bed of the patient. The stand (406) is variable to adjust the height of the apparatus (400) to be in accordance with the table of the patient. After covid, it has become much more important to have the apparatus (400) to monitor the patient’s data without entering the ICU. The apparatus (400) include tilt alerts, tube placement alerts which enable the apparatus (400) to handle all kinds of real time behavior problems. Cost being the important factor for such technology, it becomes more evident to have cost effective monitoring system makes the apparatus to be within affordable costs.

In an aspect a method for analyzing urine output by hanging a urine bag (416) to a hook of an apparatus (400) and converting the weight of the urine bag (416) into electrical signals by a transducer. The weight of the urine bag (416) is calculated by a micro-controller (413) and analyzing the weight of the urine bag (416) by a processor (414).

In an embodiment, the apparatus (400) auto-extracts the urine sample from urine bag and point of care testing is done at beside. In an embodiment, the apparatus (400), the sensor devices (350) are used to measure the on spot diagnostics at beside and transmit data to service.

In a preferred embodiment, the removal and residual urine output is not limited to create suction. The apparatus (400) also pushes the positive airflow in the tubing which creates a positive air flow with feedback control. In a preferred embodiment, the manual linking, kinks, twists of the tubes of the apparatus (400) gets blocked and due to urine drain clearance, accurate output is being measured.

While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that variants of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems, applications or methods.

Claims

I/We Claim(s):

1. An urine output monitoring apparatus (400) comprising; a load cell (410), a microcontroller (413) and a processor (414); the load cell (410) further comprising a force transducer configured to convert the weight of a urine bag (416) into an electrical signal and the micro-controller (413) is configured to calculate the weight of a urine bag (416) upon receiving the electrical signal; wherein the processor (414) is configured to analyze the measured weight of the urine bag (416) for indicating risk of at least a disease.

2. The urine output monitoring apparatus (400) as claimed in claim 1, wherein a vacuum box (310) configured to suck the urine sample from the urine catheter tube (110) and thereby accurately clearing the urine from the urine catheter tube (110).

3. The urine output monitoring apparatus (400) as claimed in claim 1, wherein the apparatus (400) further comprises a tablet holder (402) configured to receive a display unit for displaying the monitored weight of the urine bag (416).

4. The urine output monitoring apparatus (400) as claimed in claim 1, wherein the apparatus (400) is configured to share the analyzed weight of the urine bag (416) to hospital authorities.

5. The urine output monitoring apparatus (400) as claimed in claim 1, wherein the apparatus (400) is configured to provide alerts such as tube placement alerts and tilt alerts.

6. The urine output monitoring apparatus (400) as claimed in claim 1, wherein the apparatus (400) is configured to alert the hospital authorities when the analyzed weight of the urine bag (416) breaches the pre determined weight value.

7. The urine output monitoring apparatus (400) as claimed in claim 1, wherein a base (408) of the apparatus (400) further comprising castor wheels to displace the apparatus (400) from one position to another.

8. The urine output monitoring apparatus (400) as claimed in claim 1, wherein the apparatus (400) auto-extracts the urine sample from urine bag and point of care testing is done at beside;

9. The urine output monitoring apparatus (400) as claimed in claim 1, wherein the sensor devices (350) are used to measure the on-spot diagnostics at beside and transmit data to service.

10. The urine output monitoring apparatus (400) as claimed in claim 1, the apparatus (400) further pushes the positive airflow in the tubing which creates a positive air flow with feedback control.

11. A method for analyzing urine output comprising; hanging a urine bag (416) to a hook of an apparatus (400); converting the weight of the urine bag (416) into electrical signals by a transducer; calculating the weight of the urine bag (416) by a micro-controller (413); and analyzing the weight of the urine bag (416) by a processor (414).

12. The method as claimed in claim 11, wherein the apparatus (400) is configured to share the analyzed weight of the urine bag (416) to hospital authorities.

13. The method as claimed in claim 11, wherein the apparatus (400) further comprises a vacuum box (310) configured to suck the urine sample from the urine catheter tube (110) and thereby accurately clearing the urine from the urine catheter tube (110).