Patent Publication Number: US-2022233120-A1

Title: Body fluid meter assembly, in particular for measuring diuresis

Description:
TECHNICAL FIELD 
     The present invention generally relates to a body fluid meter assembly, which invention is in particular intended to be applied for the purpose of measuring diuresis. The invention also relates to a body fluid collection container and a body fluid meter unit suitable for use as part of the body fluid meter assembly. 
     BACKGROUND OF THE INVENTION 
     Body fluid meter assemblies are known as such in the art, especially for measuring diuresis. 
     Collection of urine output is typically carried out by catheterizing the patient, namely by passing a urinary catheter through the urethra of the patient and connecting the other end of the urinary catheter to a container or drainage bag through a length of flexible tubing. Typically, the container or bag collecting urine is supported below the patient from the patient&#39;s bed or an associated support system, and urine drains by gravity from the patient through the flexible tubing and into the container or bag. 
     A widespread solution for measuring diuresis consists in making manual, visual readings directly on the container or bag collecting urine. Many of these systems use urine collection bags formed of a clear and flexible plastic material provided with indicia in the form of graduations that represents the volume of urine being collected in the bag. In other systems, the urine collection receptacle includes a rigid and clear plastic reservoir in fluid communication with an additional collection bag, the reservoir being likewise provided with indicia in the form of graduations that represents the volume of urine being collected in the reservoir. In this latter case, urine initially flows and is stored in the reservoir, which acts as a measurement chamber, prior to being emptied into the additional collection bag. A determination of the quantity of urine being collected is performed visually at periodic intervals by means of the relevant graduations, which allows to derive an indication of the flow rate of urine. This solution is not entirely satisfactory in that measurement readings on the graduations are inherently inaccurate and dependent upon the caregiver making the relevant measurement readings at precise time intervals. Furthermore, measurement readings are sometimes difficult to make depending on where the system is located. This solution moreover requires emptying the bag or reservoir at regular intervals so that it has room to be filled again. 
     U.S. Pat. No. 4,712,567 A, which is incorporated herein by reference in its entirety, discloses a body fluid meter assembly used for the purpose of measuring diuresis, i.e. monitoring and measuring the quantity of urine produced by a patient during urination. More precisely, the assembly comprises a drainage collection bag configured to collect urine, a measuring and processing unit comprising a load cell and a coupling mechanism configured to releasably couple the drainage collection bag to the load cell, and flexible tubing attached to an inlet port of the drainage collection bag and configured to be connected to a urinary catheter. The drainage collection bag is coupled mechanically to the load cell via a handle assembly that is secured to an upper portion of the bag, which handle assembly is supported onto a pair of arms secured to the load cell. The measuring and processing unit processes sensor data supplied by the load cell and derives a measurement of the amount of urine being collected. In effect, the measuring and processing unit measures urine amount with regard to its weight and converts weight to volume by accounting for urine volumetric mass density. The variation of urine volume over time provides a reliable indication of the urine flow rate, which can be used to monitor the evolution of the clinical condition of the patient. 
     The coupling mechanism disclosed in U.S. Pat. No. 4,712,567 A to couple the drainage collection bag to the load cell is not robust or reliable enough, especially in that the drainage collection bag can be inadvertently released, which is not desirable. Furthermore, movements or shocks can unsettle the drainage collection bag and cause erroneous sensor measurements. 
     Other similar solutions are known in the art, for instance from International (PCT) Publications Nos. WO 2006/031249 A2, WO 2014/036769 A1, WO 2017/149272 A1, US Patent Publication No. US 2010/0228148 A1 and US Patent Publication No. US 2017/0307423 A1. All of these solutions suffer from substantially the same drawbacks as the solution disclosed in U.S. Pat. No. 4,712,567 A, namely an unreliable and unstable connection between the measuring and processing unit and the collection bag. 
     There is therefore a need for a solution which prevents inadvertent release of the container used to collect the body fluid and ensures a more reliable and stable connection between the container and the associated measuring and processing unit, while not compromising handling operations. 
     US Patent Publication No. US 2018/0214297 A1 discloses a urine output collection and monitoring system that does not rely upon the use of a load cell to derive a measurement of a quantity and/or flow rate of urine accumulating in a urine collection container. Rather, such measurement is derived by optical means, namely using a light detector array detecting a fan beam signal emitted by a light source through a portion of the urine collection container where urine accumulates. 
     SUMMARY OF THE INVENTION 
     A general aim of the invention is to provide an improved body fluid meter assembly. 
     More precisely, an aim of the invention is to provide such a solution which prevents inadvertent release of the body fluid collection container from the coupling mechanism of the associated body fluid meter unit. 
     A further aim of the invention is to provide such a solution which ensures a reliable and stable connection between the body fluid collection container and the associated body fluid meter unit. 
     Yet another aim of the invention is to provide such a solution where assembly and disassembly of the body fluid collection container is easy to handle. 
     These aims are achieved thanks to the solutions defined in the claims. 
     In accordance with the invention, there is provided a body fluid meter assembly, in particular for measuring diuresis, as defined in claim  1 , namely a body fluid meter assembly comprising (i) a body fluid collection container configured to collect body fluid, such as urine, (ii) a body fluid meter unit comprising a load cell and a coupling mechanism configured to releasably couple the body fluid collection container to the load cell, which body fluid meter unit is configured to process sensor data supplied by the load cell and derive a measurement of a quantity and/or flow rate of the body fluid accumulating in the body fluid collection container as a function of load applied on the load cell, and (iii) tubing attached to an inlet port of the body fluid collection container and configured to be connected to a source of the body fluid. According to the invention, the body fluid collection container is a substantially rigid container and the coupling mechanism is a spring-loaded interlocking mechanism configured to cooperate with one or more interlocking members provided on the body fluid collection container and interlock with the body fluid collection container to form a stable connection between the body fluid meter unit and the body fluid collection container. 
     In accordance with a preferred embodiment, the spring-loaded interlocking mechanism comprises at least one spring-loaded release lever comprising a locking portion configured to cooperate with a locking section (preferably shaped as a locking indentation) provided on a corresponding one of the one or more interlocking members. In particular, each spring-loaded release lever may be supported so as to pivot between a first position in which the locking portion of the spring-loaded release lever engages with the locking section of the corresponding interlocking member and prevents disengagement of the body fluid collection container and a second position in which the locking portion of the spring-loaded release lever is disengaged from the locking section of the corresponding interlocking member and allows disengagement of the body fluid collection container. 
     In accordance with an embodiment of the invention, the body fluid collection container comprises at least one locking extension acting as interlocking member and projecting from the body fluid collection container, each locking extension being configured to mate with a corresponding locking aperture provided on the spring-loaded interlocking mechanism. More specifically, referring to the preferred embodiment discussed in the preceding paragraph, the body fluid collection container preferably comprises first and second locking extensions acting as interlocking members and projecting from the body fluid collection container, each locking extension being configured to mate with a corresponding locking aperture provided on the spring-loaded interlocking mechanism. In this latter preferred context, the spring-loaded interlocking mechanism comprises first and second spring-loaded release levers cooperating respectively with the first and second locking extensions. 
     Each of the aforementioned locking extensions may in particular project substantially horizontally from the body fluid collection container, preferably rearward from a front side of the body fluid collection container. 
     In accordance with a particularly preferred embodiment, the spring-loaded interlocking mechanism extends from a lower side of the body fluid meter unit and an upper portion of the body fluid collection container exhibits a recess configured to receive the spring-loaded interlocking mechanism, each interlocking member being located within the recess. This ensures reliable guidance of the body fluid collection container upon engaging or disengaging the body fluid collection container from the spring-loaded interlocking mechanism. 
     By way of preference, a portion of the tubing is secured to a lateral side of the body fluid meter unit. In particular, the tubing may advantageously include a drip chamber placed upstream of the inlet port of the body fluid collection container. In this latter context, the body fluid meter unit may further comprise a secondary spring-loaded interlocking mechanism provided on the lateral side of the body fluid meter unit, which secondary spring-loaded interlocking mechanism is configured to cooperate and interlock with one or more lateral interlocking members provided on an outer portion of the drip chamber. This ensures that any tension applied on the tubing will not cause inadvertent movement of the body fluid collection container that may otherwise interfere with the measurement process. The inlet port of the drip chamber is preferably provided with a venting air inlet including an antibacterial air filtration membrane, which ensures optimal flow of the body fluid at the inlet port and prevents bacterial contamination. 
     The aforementioned secondary spring-loaded interlocking mechanism may in particular comprise at least one secondary spring-loaded release lever comprising at least one locking portion configured to cooperate with a locking section (preferably shaped as a locking indentation) provided on a corresponding one of the one or more lateral interlocking members. Preferably, the secondary spring-loaded release lever is supported so as to pivot between a first position in which the locking portion of the secondary spring-loaded release lever engages with the locking section of the corresponding lateral interlocking member and prevents disengagement of the drip chamber and a second position in which the locking portion of the secondary spring-loaded release lever is disengaged from the locking section of the corresponding lateral interlocking member and allows disengagement of the drip chamber. 
     In accordance with a variant of the invention, the drip chamber comprises at least one lateral locking extension acting as lateral interlocking member and projecting outwardly from the drip chamber, each lateral locking extension being configured to mate with a corresponding locking aperture provided on the secondary spring-loaded interlocking mechanism. More specifically, referring to the embodiment discussed in the preceding paragraph, the drip chamber preferably comprises first and second lateral locking extensions acting as lateral interlocking members and projecting from the drip chamber, each lateral locking extension being configured to mate with a corresponding locking aperture provided on the secondary spring-loaded interlocking mechanism. In this latter preferred context, the secondary spring-loaded interlocking mechanism comprises only one said secondary spring-loaded release lever cooperating with both of the first and second lateral locking extensions. 
     By way of preference, the tubing further includes a flexible tubing portion interposed between an outlet port of the drip chamber and the inlet port of the body fluid collection container. This flexible tubing portion may in particular be configured as a coiled tubing portion. 
     In accordance with another aspect of the invention, the body fluid meter unit comprises a processing unit in operative communication with an analog-to-digital (A/D) converter coupled to the load cell to convert analog signals from the load cell into digital sensor data, the processing unit being configured to digitally process the sensor data supplied by the analog-to-digital (ND) converter to derive the measurement of the quantity and/or flow rate of the body fluid accumulating in the body fluid collection container. Preferably, the processing unit is in further operative communication with one or more of the following electronic components of the body fluid meter unit, namely:
         a wireless transceiver configured to establish a wireless communication with a remote receiver and communicate data wirelessly to the remote receiver;   a near-field communication (NFC) transceiver configured to establish a near-field communication link with an external NFC device;   a battery controller coupled to a battery, in particular a rechargeable battery, supplying power to the body fluid meter unit, which battery controller is configured to monitor a charge status of the battery; and   an accelerometer configured to detect and monitor movement of the body fluid meter unit.       

     Further claimed in independent claim  27  is a body fluid collection container configured to collect body fluid, such as urine, the body fluid collection container being suitable for use as part of the aforementioned body fluid meter assembly, which body fluid collection container is a substantially rigid container comprising one or more interlocking members configured to cooperate and interlock with the spring-loaded interlocking mechanism of the body fluid meter unit. This body fluid collection container is preferably further characterized by the relevant features of the body fluid collection container discussed hereabove in connection with the body fluid meter assembly of the invention, which preferred features are recited in dependent claims  28  to  34 . 
     Also claimed in independent claim  35  is a body fluid meter unit suitable for use as part of the aforementioned body fluid meter assembly, which body fluid meter unit comprises a load cell and a coupling mechanism configured to releasably couple the body fluid collection container of the body fluid meter assembly to the load cell, the body fluid meter unit being configured to process sensor data supplied by the load cell and derive a measurement of a quantity and/or flow rate of the body fluid accumulating in the body fluid collection container as a function of load applied on the load cell. The coupling mechanism is likewise a spring-loaded interlocking mechanism configured to cooperate and interlock with one or more interlocking members provided on the body fluid collection container. This body fluid meter unit is preferably further characterized by the relevant features of the body fluid meter unit discussed hereabove in connection with the body fluid meter assembly of the invention, which preferred features are recited in dependent claims  36  to  53 . 
     Further advantageous embodiments of the invention are discussed below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the present invention will appear more clearly from reading the following detailed description of embodiments of the invention which are presented solely by way of non-restrictive examples and illustrated by the attached drawings in which: 
         FIG. 1A  is a schematic perspective view of a body fluid meter assembly, as seen from a front side, in accordance with a preferred embodiment of the invention, which body fluid meter assembly includes a body fluid meter unit that is coupled to a body fluid collection container via a spring-loaded interlocking mechanism; 
         FIG. 1B  is a schematic perspective view of the body fluid meter assembly of  FIG. 1A , as seen from a rear side; 
         FIG. 1C  is an enlarged partial perspective view of a lateral side of the body fluid meter unit of  FIGS. 1A and 1B , where tubing is attached to an inlet port of the body fluid collection container; 
         FIG. 2A  is a schematic perspective view of the assembly of  FIGS. 1A to 1C , with the body fluid meter unit removed from the body fluid collection container and showing the body fluid collection container and associated tubing from a rear side; 
         FIG. 2B  is an enlarged partial perspective view of a portion of the tubing upstream of the inlet port of the body fluid collection container where a drip chamber is provided; 
         FIG. 3A  is a schematic perspective view, as seen from a rear side, of the body fluid collection container forming part of the assembly shown in  FIGS. 1A to 1C ; 
         FIG. 3B  is a rear view of the body fluid collection container of  FIG. 3A ; 
         FIG. 3C  is a top view of the body fluid collection container of  FIG. 3A ; 
         FIG. 3D  is an enlarged partial perspective view of an upper portion of the body fluid collection container of  FIG. 3A  showing a pair of interlocking members used to couple the body fluid collection container to the associated spring-loaded interlocking mechanism of the body fluid meter unit as shown for instance in  FIGS. 1A to 1C, 4A to 4E, 5 and 6 ; 
         FIG. 4A  is a front view of the body fluid meter unit forming part of the assembly shown in  FIGS. 1A to 1C ; 
         FIG. 4B  is a side view of the body fluid meter unit of  FIG. 4A ; 
         FIG. 4C  is a top view of the body fluid meter unit of  FIG. 4A ; 
         FIG. 4D  is a bottom view of the body fluid meter unit of  FIG. 4A ; 
         FIG. 4E  is an enlarged partial perspective view of the spring-loaded interlocking mechanism of the body fluid meter unit of  FIG. 4A ; 
         FIG. 5  is an enlarged partial perspective view of a part of the spring-loaded interlocking mechanism of  FIG. 4E  coupled to the pair of interlocking members of the body fluid collection container, with an upper housing part of the spring-loaded interlocking mechanism being omitted for the sake of illustration; 
         FIG. 6  is a partial perspective view of the spring-loaded interlocking mechanism of  FIG. 4E  secured to a load cell of the body fluid meter unit; 
         FIG. 7A  is an enlarged partial perspective view of a secondary spring-loaded interlocking mechanism provided on the lateral side of the body fluid meter unit for coupling to the drip chamber shown in  FIGS. 2A and 2B ; 
         FIG. 7B  is an enlarged partial perspective view of a part of the secondary spring-loaded interlocking mechanism of  FIG. 7A , with an outer cover part of the secondary spring-loaded interlocking mechanism being omitted for the sake of illustration; and 
         FIG. 8  is a functional block diagram illustrating functional electronic components of the body fluid meter unit according to a preferred embodiment. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     The present invention will be described in relation to various illustrative embodiments. It shall be understood that the scope of the invention encompasses all combinations and sub-combinations of the features of the embodiments disclosed herein. 
     As described herein, when two or more parts or components are described as being connected, secured, attached or coupled to one another, they can be so connected, secured, attached or coupled directly to each other or through one or more intermediary parts. 
     The invention will be described in relation to various embodiments of a body fluid meter assembly as shown in  FIGS. 1A-B  to  8 , which assembly is especially intended to measure diuresis. 
       FIGS. 1A to 1C  are illustrative of a particularly preferred embodiment of the body fluid meter assembly according to the invention, which assembly is generally designated by reference numeral  1 . The body fluid meter assembly  1  basically includes three main components, namely a body fluid meter unit  10 , a body fluid collection container  20  configured to collect body fluid (i.e. urine in the present example), and tubing  30  attached to an inlet port  20 A of the body fluid collection container  20  and configured to be connected to a source of the body fluid (namely a urinary catheter in the present instance, not shown) by means of tubing portion  31 . While not specifically shown, the inlet port  20 A may advantageously be provided with an anti-reflux valve to prevent retrograde flow of urine into the tubing  30 , thereby preventing retrograde migration of bacteria. 
     The body fluid meter unit  10  comprises a load cell (not shown in  FIGS. 1A to 1C , but visible in  FIG. 6 ) and a coupling mechanism configured to releasably couple the body fluid collection container to the load cell (see also the functional diagram of  FIG. 8 ). The body fluid meter unit  10  is in essence configured to process sensor data supplied by the load cell and derive a measurement of a quantity and/or flow rate of the urine accumulating in the body fluid collection container  20  as a function of load applied on the load cell. The basic measurement principle is known per se in the art, for instance from U.S. Pat. No. 4,712,567 A, the disclosure of which is incorporated herein by reference in its entirety. 
     In use, the body fluid meter unit  10  is attached to a bed frame, or to a separate, stable support structure, by means of a suitable attachment mechanism (not shown), such as fastening straps or clamps. A suitable attachment mechanism may in particular be provided on a rear side of the body fluid meter unit  10 . 
     Improvements are achieved in terms of measurement accuracy and reliability thanks to the invention. More specifically, in the context of the present invention, use is made of a substantially rigid container as the body fluid collection container  20 , which ensures that accumulation of urine in the container is made in a deterministic way and does not lead to uncontrolled deformation of the collection container, which could negatively impact measurement accuracy and reliability. In that regard, the body fluid collection container  20  can be made of any suitably rigid material, including plastic materials, such as polycarbonates. The material can be opaque or substantially transparent, in which case the container  20  could additionally be provided with graduations, as known in the art, to allow visual measurements of the diuresis. 
     As is conventional in the art, the container  20  may be provided with a drainage port  20 B to allow emptying of the container  20 . While not shown, a suitable, manually-actuatable rotary flush valve could be provided at the drainage port  20 B to facilitate the emptying operation. In that respect, an upper side  20 . 2  of the body fluid collection container  20  can additionally be provided with a venting air inlet  200  (with antibacterial air filtration membrane) which ensures optimal and quick emptying of the container  20 . 
     Furthermore, the coupling mechanism used to couple the container  20  to the meter unit  10  is specifically designed as a spring-loaded interlocking mechanism, designated by reference numeral  50 , that is configured to cooperate with one or more interlocking members (not visible in  FIGS. 1A to 1C ) provided on the container  20 . This is a fundamental difference compared to the known solutions that make use of rather rudimentary handle and hook arrangements. Thanks to the invention, a stable connection is formed between the body fluid meter unit  10  and the body fluid collection container  20 . Furthermore, inadvertent release of the container  20  from the meter unit  10  is prevented. While more robust and reliable, this solution does not negatively impact handling operations, as the container  20  can easily be coupled to or uncoupled from the meter unit  10  by simple engagement or disengagement of the interlocking mechanism  50  as this will be explained below. 
     In the illustrated example, a pair of interlocking members are provided for cooperation with the spring-loaded locking mechanism  50 , as shown for instance in  FIG. 2A  and  FIGS. 3A to 3D . More precisely, first and second locking extensions  250   a ,  250   b  acting as interlocking members are provided, which locking extensions  250   a ,  250   b  project from the body fluid collection container  20 . By way of preference, as shown, each locking extension  250   a ,  250   b  projects substantially horizontally from the body fluid collection container  20 , namely rearward from a front side  20 . 1  of the body fluid collection container  20 . In the illustrated example, the locking extensions are advantageously located within a recess  20   a  formed in an upper portion of the body fluid collection container  20 , the locking extensions  250   a ,  250   b  being supported by and projecting rearward from a wall section  25  extending partly in the recess  20   a , along the front side  20 . 1  of the container  20  (see especially  FIGS. 3A to 3D ). 
     The locking extensions  250   a ,  250   b  are configured to mate with corresponding locking apertures  50   a ,  50   b  provided on the spring-loaded interlocking mechanism  50 , as shown in particular in  FIGS. 4A, 4E and 6 . The overall shape of the locking extensions  250   a ,  250   b  and associated locking apertures  50   a ,  50   b  may vary, but are preferably chosen in such a way as to facilitate engagement and disengagement of the interlocking mechanism  50  with or from the locking extensions  250   a ,  250   b  and ensure a stable and reliable guidance and support of the container  20 . 
     In the illustrated example, one may appreciate that the spring-loaded interlocking mechanism  50  advantageously extends from a lower side  10 . 1  of the body fluid meter unit  10  and that the recess  20   a  formed in the upper portion of the body fluid collection container  20  is configured to entirely receive the spring-loaded interlocking mechanism  50 , which also favors and facilitates engagement and disengagement of the container  20 . The recess  20   a  in effect advantageously acts as a guide for engagement and disengagement of the container  20  with respect to the spring-loaded interlocking mechanism  50 . This also leads to an overall compact assembly as depicted in  FIGS. 1A and 1B . 
     As shown in greater detail in  FIG. 6 , the spring-loaded interlocking mechanism  50  is directly coupled to the associated load cell, designated by reference numeral  15 , of the body fluid meter unit  10 , which load cell  15  is housed within the unit  10 . To this end, an upper housing part  51  of the spring-loaded interlocking mechanism  50  is provided with an extension  51 A (also partly visible in  FIG. 4E ) projecting upward through a corresponding opening (not shown) formed in the lower side  10 . 1  of the body fluid meter unit  10 . This upper housing part  51  is secured to a lower housing part  52  to house the various mechanical components of the spring-loaded interlocking mechanism  50  which will be detailed hereafter. 
     As this is readily visible in  FIG. 6 , the load cell  15  is preferably an S-type load cell comprising an S-shaped block that is secured, at an upper end, to a suitable portion of the body fluid meter unit  10  and, at a lower end, to the spring-loaded interlocking mechanism  50  (and the associated container  20 , when engaged), thereby allowing a measurement of the load applied on the load cell  15 . S-type load cells (as well as other types of load cells) are commercially available on the market, for instance from company Mettler-Toledo (Schweiz) GmbH (www.mt.com), and are used for a large variety of applications. Load cells with increased resistance to traction (exceeding e.g. 100 kg of traction or more) are of particular interest with a view to prevent damage to the load cell, for instance as a result of the body fluid collection container  20  getting stuck during movement of the patient&#39;s bed or someone stepping up on the body fluid collection container  20 . 
     By way of preference, the spring-loaded interlocking mechanism  50  comprises at least one spring-loaded release lever cooperating with the aforementioned one or more interlocking members. More precisely, in the illustrated example, two such spring-loaded release levers  55   a ,  55   b  are provided, as shown in  FIGS. 1A, 4A to 4E, 5 and 6 , for cooperation with, respectively, the first and second locking extensions  250   a ,  250   b . Each of these spring-loaded release levers  55   a ,  55   b  comprises a locking portion  55 A, respectively  55 B, that is partly visible in  FIGS. 4A and 4E  and more fully in  FIG. 5 . Each locking portion  55 A,  55 B is configured to cooperate with a locking section  250 A, respectively  250 B, provided on the corresponding interlocking member  250   a ,  250   b . In the illustrated example, the locking sections  250 A,  250 B advantageously take the shape of locking indentations (see also  FIGS. 2A and 3A to 3D ) formed at a distal end of the locking extensions  250   a ,  250   b . As shown in greater detail in  FIG. 5  (where the upper housing part  51  of the spring-loaded interlocking mechanism  50  has been omitted for the purpose of illustration), each locking portion  55 A,  55 B engages with the associated locking indentation  250 A, respectively  250 B, upon full engagement of the container  20  with the spring-loaded interlocking mechanism  50 , thereby locking the container  20  in place. Conversely, disengagement of the locking portions  55 A,  55 B from the associated locking indentations  250 A,  250 B frees the locking extensions  250   a ,  250   b , thereby allowing disengagement of the container  20  from the interlocking mechanism  50 . 
     As this is more readily visible in  FIG. 5 , each release lever  55   a ,  55   b  is preferably supported (here between the upper and lower housing parts  51 ,  52  of the interlocking mechanism  50 ) so as to pivot about a pivot point  55 . 1 , respectively  55 . 2 , thereby allowing each release lever  55   a ,  55   b  to move between a first position (as depicted in  FIG. 5 ) in which the locking portion  55 A, respectively  55 B, engages with the locking section  250 A, respectively  250 B, (thereby preventing disengagement of the body fluid collection container  20 ) and a second position in which the locking portion  55 A, respectively  55 B, is disengaged from the locking section  250 A, respectively  250 B, (thereby allowing disengagement of the body fluid collection container  20 ). 
     By default, when no action is applied on the release levers  55   a ,  55   b , the release levers  55   a ,  55   b  are pushed to the aforementioned first position under the action of a spring element (not shown) located in a recess portion  56  (see  FIG. 5 ) between the two release levers  55   a ,  55   b.    
     The geometry and arrangement of the locking extensions  250   a ,  250   b  and of the release levers  55   a ,  55   b  (especially the shape of the leading, frontal face of the locking extensions  250   a ,  250   b  and the shape of the locking portions  55 A,  55 B) is chosen in such a way that insertion of the locking extensions  250   a ,  250   b  inside the associated locking apertures  50   a ,  50   b  causes the release levers  55   a ,  55   b  to be pivoted away from their first, engaging position, towards the second, disengaging position. Upon full and complete engagement of the container  20 , the release levers  55   a ,  55   b  are automatically pushed back to the first, engaging position under the action of the associated spring element, thereby locking the container  20  in place on the interlocking mechanism  50 . Disengagement of the container  20  is achieved by simply pressing the two levers  55   a ,  55   b  towards each other, against the action of the spring element. 
     A further advantageous aspect of the invention will now be discussed with reference to  FIGS. 1A to 1C, 2A, 2B, 4A to 4E, 7A and 7B , namely in relation to the tubing  30  that is attached to the inlet port  20 A of the body fluid collection container  20 . Considering that the tubing  30  is connected to the container  20 , which is suspended below the meter unit  10 , movement of the tubing  30 , such as caused by manipulation of the tubing portion  31 , may negatively impact the measurement accuracy. To prevent this from happening, a portion of the tubing  30  is preferably secured to a lateral side  10 . 2  of the body fluid meter unit  10 , which in effect isolates the body fluid collection container  20  from any perturbation caused by movement of the tubing  30 . 
     Even more preferably, the tubing  30  includes, as shown, a drip chamber (also referred to as Pasteur drip chamber)  32  placed upstream of the inlet port  20 A of the body fluid collection container  20 , which drip chamber  32  is secured to the lateral side  10 . 2  of the body fluid meter unit  10 . In the illustrated example, this is advantageously achieved by providing the meter unit  10  with a secondary spring-loaded interlocking mechanism  60 , secured to the lateral side  10 . 2  of the meter unit  10 , which secondary spring-loaded mechanism is configured to cooperate and interlock with one or more lateral interlocking members (not visible in  FIGS. 1A to 1C ) provided on an outer portion of the drip chamber  32 . 
     An inlet port  32 A of the drip chamber  32 , which is connected to the tubing portion  31 , is preferably provided with a venting air inlet  320  including an antibacterial air filtration membrane, which improves the flow of body fluid at the inlet port  20 A of the container  20 , while preventing bacterial contamination. 
     In the illustrated example, a pair of lateral interlocking members are provided for cooperation with the spring-loaded locking mechanism  60 , as shown in  FIGS. 2A and 2B . More precisely, the drip chamber  32  comprises first and second lateral locking extensions  360   a ,  360   b  acting as lateral interlocking members, which lateral locking extensions  360   a ,  360   b  project outwardly from the drip chamber  32 . Each lateral locking extension  360   a ,  360   b  is configured to mate with a corresponding locking aperture  60   a , respectively  60   b , provided on the secondary spring-loaded interlocking mechanism  60 , as depicted for instance in  FIGS. 4B and 7A . The overall shape of the lateral locking extensions  360   a ,  360   b  and associated locking apertures  60   a ,  60   b  may once again vary, but are preferably chosen in such a way as to facilitate engagement and disengagement of the secondary interlocking mechanism  60  with or from the lateral locking extensions  360   a ,  360   b  of the drip chamber  32 . 
     The secondary spring-loaded interlocking mechanism  60  is functionally similar to the spring-loaded interlocking mechanism  50  and ensures a stable and reliable connection between the drip chamber  32  and the body fluid meter unit  10 . In the illustrated example, the secondary spring-loaded interlocking mechanism  60  includes an outer cover part  61  and an inner cover part  62  secured to the lateral side  10 . 2  of the body fluid meter unit  10 , the outer cover part  61  and inner cover part  62  jointly housing the mechanical components of the secondary spring-loaded interlocking mechanism  60 . 
     By way of preference, the secondary spring-loaded interlocking mechanism  60  comprises at least one secondary spring-loaded release lever cooperating with the aforementioned one or more lateral interlocking members. More precisely, in the illustrated example, one such spring-loaded release lever  65  is provided, as shown in  FIGS. 1A, 1C, 4A to 4D, 7A and 7B , for cooperation with both the first and second locking extensions  360   a ,  360   b . In the illustrated example, the spring-loaded release lever  65  comprises first and second locking portions  65 A,  65 B that are partly visible in  FIGS. 4B and 7A  and more fully in  FIG. 7B . Each locking portion  65 A,  65 B is configured to cooperate with a locking section  360 A, respectively  360 B, provided on the corresponding lateral interlocking member  360   a ,  360   b . In the illustrated example, the locking sections  360 A,  360 B advantageously take the shape of locking indentations (see in particular  FIG. 2B ) formed at a distal end of the locking extensions  360   a ,  360   b . As this may be appreciated from looking at  FIG. 7A  and  FIG. 7B  (where the outer cover part  61  of the secondary spring-loaded interlocking mechanism  60  has been omitted for the purpose of illustration), each locking portion  65 A,  65 B is positioned in such a way as to engage with the associated locking indentation  360 A, respectively  360 B, upon full engagement of the drip chamber  32  with the secondary spring-loaded interlocking mechanism  60 , thereby locking the drip chamber  32  in place. Conversely, disengagement of the locking portions  65 A,  65 B from the associated locking indentations  360 A,  360 B frees the lateral locking extensions  360   a ,  360   b , thereby allowing disengagement of the drip chamber  32  from the secondary interlocking mechanism  60 . 
     As this is more readily visible in  FIG. 7B , the secondary release lever  65  is preferably supported (here between the outer cover part  61  and the inner cover part  62  of the secondary interlocking mechanism  60 ) so as to pivot about a pivot point  65 . 1 , thereby allowing the release lever  65  to move between a first (lowered) position (as depicted in the illustrations) in which the locking portions  65 A,  65 B engage with the locking sections  360 A,  360 B (thereby preventing disengagement of the drip chamber  32 ) and a second (raised) position in which the locking portions  65 A,  65 B are disengaged from the locking section  360 A,  360 B (thereby allowing disengagement of the drip chamber  32 ). 
     By default, when no action is applied on the release lever  65 , the release lever  65  is pushed to the aforementioned first, lowered position under the action of a spring element (not shown) located in a blind recess portion  66  (see  FIG. 7B ) formed in cover parts  61 ,  62 , above the position of the lever  65 . 
     The geometry and arrangement of the locking extensions  360   a ,  360   b  and of the release lever  65  (especially the shape of the leading, frontal face of the locking extensions  360   a ,  360   b  and the shape of the locking portions  65 A,  65 B) is chosen in such a way that insertion of the locking extensions  360   a ,  360   b  inside the associated locking apertures  60   a ,  60   b  causes the release lever  65  to be pivoted away from its first, engaging position, towards the second, disengaging position. Upon full and complete engagement of the drip chamber  32 , the release lever  65  is automatically pushed back to the first, engaging position under the action of the associated spring element, thereby locking the drip chamber  32  in place on the secondary interlocking mechanism  60 . Disengagement of the drip chamber  32  is achieved by simply pushing the lever  65  upward, in the illustrated example, against the action of the spring element. 
     As this can be appreciated from looking at the illustrations of  FIGS. 2A, 2B, 4B, 7A and 7B , the drip chamber  32  is advantageously further provided with a guide member  360   c  formed as a further lateral extension projecting outwardly from the drip chamber  32 , which guide member  360   c  is configured to mate with a corresponding guiding aperture  60   c  provided on the secondary spring-loaded interlocking mechanism  60  to ensure a stable connection between the drip chamber  32  and the meter unit  10 . 
     In addition to the aforementioned drip chamber  32 , the tubing  30  preferably further comprises a flexible tubing portion  33  interposed between an outlet port  32 B of the drip chamber  32  and the inlet port  20 A of the body fluid collection container  20  as shown in  FIGS. 1A to 1C, 2A and 2B . As illustrated, this flexible tubing portion  33  may advantageously be configured as a coiled tubing portion, which adequately copes with the fact that the container  20  is suspended under the meter unit  10  and prevents any interference with the measurement process. 
       FIG. 8  is a functional block diagram illustrating functional electronic components of the body fluid meter unit  10  in accordance with a preferred embodiment. In the illustrated embodiment, the body fluid meter unit  10  is preferably battery-operated and includes a battery  18  providing power to the body fluid meter unit  10 . Also schematically depicted in  FIG. 8  is the load cell  15  coupled to the body fluid collection container  20  via the spring-loaded interlocking mechanism  50 . 
     The illustrated meter unit  10  further includes a printed circuit board  100  carrying electronic components necessary to condition and process the sensor signals produced by the load cell  15 , including an analog-to-digital (ND) converter  115  coupled to the load cell  15  and designed to convert analog signals from the load cell  15  into processable digital sensor data. The A/D converter  115  is in operative communication with a processing unit  101  (such as a suitable CPU or microcontroller) that is programmed to digitally process the sensor data supplied by the A/D converter to derive the measurement of the quantity and/or flow rate of the body fluid accumulating in the container  20 . 
     The processing unit  101  is preferably in further operative communication with additional electronic components of the body fluid meter unit  10  that are likewise provided on the PCB  100 , namely:
         a wireless transceiver  105  configured to establish a wireless communication with a remote receiver and communicate data wirelessly to the remote receiver;   a near-field communication (NFC) transceiver  106  configured to establish a near-field communication link with an external NFC device;   a battery controller  118  coupled to the battery  18 , which battery controller  118 ) is configured to monitor a charge status of the battery  18 ; and   an accelerometer  120  configured to detect and monitor movement of the body fluid meter unit  10 .       

     The wireless transceiver  105  is in particular of use to wirelessly communicate data representative of the measured quantity and/or flow rate of body fluid to a remote device such as a computer, tablet or the like. Additional software could be implemented on said computer or tablet to provide high-level information to the end-user, such as an indication of the actual flow rate of body fluid being recorded, as well as statistics illustrative of the evolution of the body fluid output and other information relating to the clinical condition of the patient. 
     The NFC transceiver  106  may especially be of interest to establish a secure communication link between the body fluid meter unit  10  and a configurator device for the purpose e.g. of configurating and setting up the body fluid meter unit  10 . This NFC transceiver  106  may in particular be of use for authentication purposes to ensure that only authorized personnel can have administrative access to functionalities and configuration options of the body fluid meter unit  10 . 
     With regard to the battery controller  118 , the battery  18  may especially be a rechargeable battery, such as a lithium-ion battery, in which case a suitable monitoring and control of the battery charge status and charge cycle needs to be ensured. Reference numeral  10 A in  FIG. 8  designates a suitable connector for connection to an external battery charger, which connector  10 A is also visible in  FIGS. 4A, 4B and 4D , here provided on the lower side  10 . 1  of the meter unit  10 . Reference numeral  10 B in  FIGS. 4A, 4B and 4D  designates a status LED (not shown in  FIG. 8 ) which can be used to provide a visual indication of the power status of the body fluid meter unit  10  and of the charge status of the battery  18 . 
     The accelerometer  120  is of particular interest to detect and monitor movements of the body fluid meter unit  10  that could interfere with or otherwise affect the measurement accuracy. In that respect, movements that could cause spurious sensor signals from the load cell  15  can be detected by the accelerometer and the relevant spurious data be discarded or filtered out. The accelerometer  120  may in particular be a triaxial (or three-dimensional) accelerometer  120  configured to detect movements in all directions. 
     Further electronic components or functionalities could be contemplated. In particular, the processing unit  101  can be configured to monitor the quantity and/or flow rate of body fluid and allow setting up of corresponding detection thresholds to trigger alarms, such as in case the detected quantity or flow rate of body fluid exceeds or falls under a predetermined detection threshold. An alarm may for instance be set up to be triggered when the body fluid collection container  20  needs to be emptied. In that context, the body fluid meter unit  10  could additionally be provided with an integrated sound-generating device and/or visual indicator to generate an audible and/or visual alarm. 
     Various modifications and/or improvements may be made to the above-described embodiments without departing from the scope of the invention as defined by the appended claims. 
     For instance, while the illustrated embodiments show a spring-loaded interlocking mechanism comprising at least one spring-loaded release lever, this preferred feature is optional, and one may alternatively contemplate to design the spring-loaded interlocking mechanism in such a way that release of the interlocking members is caused by insertion of an adequate tool or dedicated release element. The use of one or more spring-loaded release levers is nevertheless preferred in that this greatly facilitates handling operations. 
     In addition, the spring-loaded interlocking mechanism could alternatively make use of so-called snap-fit interlocking elements that integrate the spring components, namely elements exhibiting elastic interlocking portions or sections. The illustrated embodiment nevertheless remains a preferred solution in that all movable components of the spring-loaded interlocking mechanism are an integral part of the body fluid meter unit, which does not negatively impact the complexity of the associated body fluid collection container. The production costs of the body fluid collection container per se are therefore comparable to those of conventional body fluid collection containers or bags. 
     LIST OF REFERENCE NUMERALS AND SIGNS USED THEREIN 
     
         
           1  body fluid meter assembly (e.g. diuresis meter assembly) 
           10  body fluid meter unit of body fluid meter assembly  1  (e.g. diuresis meter unit) 
           10 A battery charger connector 
           10 B status LED 
           10 . 1  lower side of body fluid meter unit  10   
           10 . 2  lateral side of body fluid meter unit  10   
           15  load cell (e.g. S-beam type load cell) 
           18  (rechargeable) battery 
           20  body fluid collection container of body fluid meter assembly  1  configured to collect body fluid (e.g. urine) 
           20   a  recess formed in upper portion of body fluid collection container  20  and configured to receive spring-loaded interlocking mechanism  50   
           20 A inlet port of body fluid collection container  20   
           20 B drainage port of body fluid collection container  20   
           20 . 1  front side of body fluid collection container  20   
           20 . 2  upper side of body fluid collection container  20   
           25  wall section extending in recess  20   a , along front side  20 . 1  of body fluid collection container  20  and supporting interlocking members  250   a ,  250   b    
           30  tubing of body fluid meter assembly  1   
           31  tubing portion connected to source of body fluid (e.g. urinary catheter) 
           32  drip chamber 
           32 A inlet port of drip chamber  32   
           32 B outlet port of drip chamber  32   
           33  flexible tubing portion (e.g. coiled tubing portion) interposed between outlet port  32 B of drip chamber  32  and inlet port  20 A of body fluid collection container  20   
           50  spring-loaded interlocking mechanism (coupling mechanism) configured to releasably couple the body fluid collection container  20  to the load cell  15   
           50   a  (first) locking aperture of spring-loaded interlocking mechanism  50  configured to receive interlocking member  250   a    
           50   b  (second) locking aperture of spring-loaded interlocking mechanism  50  configured to receive interlocking member  250   b    
           51  upper housing part of spring-loaded interlocking mechanism  50   
           51 A extension of upper housing part  51  secured to load cell  15   
           52  lower housing part of spring-loaded interlocking mechanism  50   
           55   a  (first) spring-loaded release lever configured to cooperate with interlocking member  250   a    
           55 A locking portion of spring-loaded release lever  55   a  configured to cooperate with locking section  250 A provided on interlocking member  250   a    
           55 . 1  pivot point of spring-loaded release lever  55   a    
           55   b  (second) spring-loaded release lever configured to cooperate with interlocking member  250   b    
           55 B locking portion of spring-loaded release lever  55   b  configured to cooperate with locking section  250 B provided on interlocking member  250   b    
           55 . 2  pivot point of spring-loaded release lever  55   b    
           56  recess portion configured to receive spring element acting on release levers  55   a ,  55   b    
           60  secondary spring-loaded interlocking mechanism 
           60   a  (first) locking aperture of secondary spring-loaded interlocking mechanism  60  configured to receive interlocking member  360   a    
           60   b  (second) locking aperture of secondary spring-loaded interlocking mechanism  60  configured to receive interlocking member  360   b    
           60   c  guiding aperture of secondary spring-loaded interlocking mechanism  60  configured to receive guide member  360   c    
           61  outer cover part of secondary spring-loaded interlocking mechanism  60   
           62  inner cover part of secondary spring-loaded interlocking mechanism  60  (secured to lateral side  10 . 2  of body fluid meter unit  10 ) 
           65  secondary spring-loaded release lever configured to cooperate with interlocking members  360   a  and  360   b    
           65 A (first) locking portion of secondary spring-loaded release lever  65  configured to cooperate with locking section  360 A provided on interlocking member  360   a    
           65 B (second) locking portion of secondary spring-loaded release lever  65  configured to cooperate with locking section  360 B provided on interlocking member  360   b    
           65 . 1  pivot point of secondary spring-loaded release lever  65   
           66  recess portion configured to receive spring element acting on release lever  65   
           100  printed circuit board (PCB) 
           101  processing unit (e.g. CPU) 
           105  wireless transceiver 
           106  near-field communication (NFC) transceiver 
           115  analog-to-digital (ND) converter 
           118  battery controller 
           120  accelerometer 
           200  venting air inlet (with antibacterial air filtration membrane) provided on upper side  20 . 2  of body fluid collection container  20   
           250   a  (first) interlocking member (e.g. first locking extension) provided on body fluid collection container  20  and configured to cooperate with spring-loaded interlocking mechanism  50   
           250 A locking section (e.g. locking indentation) of interlocking member  250   a  configured to engage with (e.g. receive) locking portion  55 A of spring-loaded release lever  55   a    
           250   b  (second) interlocking member (e.g. second locking extension) provided on body fluid collection container  20  and configured to cooperate with spring-loaded interlocking mechanism  50   
           250 B locking section (e.g. locking indentation) of interlocking member  250   b  configured to engage with (e.g. receive) locking portion  55 B of spring-loaded release lever  55   b    
           320  venting air inlet (with antibacterial air filtration membrane) provided at inlet port  32 A of drip chamber  32   
           360   a  (first) lateral interlocking member (e.g. first lateral locking extension) provided on outer portion of drip chamber  32  and configured to cooperate with secondary spring-loaded interlocking mechanism  60   
           360 A locking section (e.g. locking indentation) of lateral interlocking member  360   a  configured to engage with (e.g. receive) locking portion  65 A of secondary spring-loaded release lever  65   
           360   b  (second) lateral interlocking member (e.g. second lateral locking extension) provided on outer portion of drip chamber  32  and configured to cooperate with secondary spring-loaded interlocking mechanism  60   
           360 B locking section (e.g. locking indentation) of lateral interlocking member  360   b  configured to engage with (e.g. receive) locking portion  65 B of secondary spring-loaded release lever  65   
           360   c  guide member provided on outer portion of drip chamber  32  and configured to cooperate with secondary spring-loaded interlocking mechanism  60