HK1215661B - Handheld medical instrument and system for analyzing a body fluid - Google Patents

Description

Handheld medical instruments and systems for analyzing body fluids

Technical Field

The present invention relates to a handheld medical instrument for analyzing body fluids, particularly for blood glucose testing, comprising a housing and a transport mechanism, the housing having a cartridge compartment configured to receive a replaceable tape cartridge, and the transport mechanism including a manually operated manual actuator operable by a user to rotate a tape spool of the tape cartridge, causing a test strip in the tape cartridge to be wound forwardly onto the spool and providing functional elements stored on the test strip for continued use. The present invention also relates to a system comprising such an instrument and a disposable tape cartridge, and a method of operating the same.

Background Art

In practice, similar motorized devices are used as blood glucose meters for the self-diagnosis of diabetes. A plurality of test zones are provided on the test strip that can be wound on a bobbin in a tape cassette. After the application of a small amount of blood sample, the reaction test zone is checked photometrically in order to determine the glucose content as accurately and reliably as possible. This type of tape cassette is intended to be inserted into a compact handheld device housing with a disposable component in order to allow the necessary analytical steps to be automatically and quickly implemented. For simplified system design, it has been proposed in EP-A 1 702 565 to use a tape cassette that can be manually operated by means of a rod arranged outside the device housing.

Summary of the Invention

On this basis, the object of the present invention is to further improve the known test instruments and systems and methods of operation and to achieve reliable functionality with a simplified and cost-effective design.

This object is achieved by the combination of features stated in claim 1. Advantageous embodiments and further developments of the invention are revealed in the dependent claims.

The present invention is based on the concept of using an automatic device to secure the proper tape position. Therefore, the present invention provides a stop device acting on the conveyor mechanism and designed to stop the test tape in the functional position of the functional element. The stop device is configured to interrupt the instrument unit's tape transport as needed. This keeps operation simple for the user, allowing them to focus on the drive. Furthermore, the exact functional position can be determined, ensuring reliable measurements and tape transport distance during consecutive tests, even with varying functional positions. The user does not have to forgo the improved convenience offered by the large number of tests that can be stored on the tape and the ease of disposing of used material on discarded tape spools. Compared to automated drive devices, the manufacture of this instrument can be simplified, and the risk of motor stalling is avoided. Overall, the device's power consumption can be minimized, and a high-power internal supply is unnecessary.

In a preferred embodiment, the stop device includes a position detection unit, preferably comprising a contactless scanning sensor, adapted to detect the functional position of the functional element on the test strip. This allows for targeted stopping even in the event of strip slippage or tolerances in the distances between the functional elements of the strip. Contactless scanning also allows for accurate positioning without the need for complex strip designs or mechanical engagement. The position detection unit can detect the functional element in a given position directly or indirectly. In the latter case, the stop device can include an optional sensor adapted to detect position markings on the test strip and provide a trigger signal to stop the test strip.

Another particularly advantageous embodiment provides that the locking device has a locking unit that can be actuated for mechanical blocking of the conveying mechanism. This provides a secure locking by simple measures.

To further allow precise actuation, it is advantageous for the detent device to have a solenoid-operated locking actuator and a return spring to provide a locking force against rotation of the spool when the actuator is released.

It is also advantageous if the stop device has a control member which is linked to the manual drive to prevent blocking of the conveying mechanism in the initial conveying phase. Thus, it is also possible to avoid excessive power consumption.

In order to avoid excessive forces on the test strip, it is advantageous if the transport mechanism can be switched into an idle state by means of a stop device when it reaches the functional position.

In order to further reduce the construction effort, it is also conceivable that the stop device has a position indication unit for providing the user with a perceptible visual, acoustic or tactile indication to stop the actuation of the manual drive, thereby allowing the user to act on the conveying mechanism in a very simple manner.

A further improvement in safe and reliable manual operation can be achieved when the manual drive comprises a rotationally mounted or linearly guided push rod and a pinion, wherein the push rod can be operated by the user, and the pinion engages teeth on the push rod and converts the movement of the push rod into rotational movement to rotate the belt shaft.

A further improvement in this respect is based on a transmission mechanism having a freewheel assembly which allows the transfer of rotational movement to the belt shaft in only one direction, while preventing movement in the opposite direction.

For reliable torque transmission, it is advantageous if the transmission mechanism has a gear which can be rotated by means of a manual drive and which can be blocked by a stop and wherein the gear is directly coupled to the belt shaft via a connecting journal when the belt cassette is inserted in the cassette compartment.

In order to avoid excessive loads, it is advantageous if the transmission mechanism has a speed indication unit for providing a user with a perceptible visual, acoustic or tactile signal indicating the rotation speed of the belt shaft.

It is also conceivable that the transmission mechanism comprises an electrical energy generator and an electric motor, the generator being operable by a manual drive and the electric motor being supplied with energy from the generator, preferably via a supercapacitor serving as storage device.

For further automation of the positioning, it can be advantageous for the conveying mechanism to comprise a reserve device for storing mechanical energy, preferably a spring which can be loaded by a manual drive, in order to automatically rotate the belt shaft during the conveying cycle.

To obtain reliable measurements, the test strip can have a series of strip sections, each of which includes a functional element configured as a test zone for application of a body fluid and at least one additional functional element, specifically a calibration zone. Generally, the term "functional element" as used herein refers to a distinct element or zone on a test strip that can be positioned by strip transport to assume a functional position in which an instrument operation (specifically, a measurement mode) is supported or triggered.

The invention also relates to a medical system for analyzing body fluids, in particular for blood glucose testing, comprising a cassette comprising a test strip and a handheld instrument comprising:

a housing having a cassette compartment configured to receive a tape cassette,

a transport mechanism including a manual drive actuable by a user to rotate the tape spool of the tape cassette so that the test strip is wound forward and the plurality of functional elements stored thereon are provided for sequential use,

A stop device acts on the transport mechanism and is designed to stop the test strip in the functional position of a functional element provided on the test strip.

With regard to the advantageous effects of such a system, reference is made to the previous statements.

Procedurally, a method for operating a handheld medical instrument for analyzing body fluids is provided, the method comprising the following steps:

- inserting a replaceable cassette containing the test strips into a cassette compartment provided in the housing of the instrument,

- actuating a manual drive of the transport mechanism in order to rotate the tape spool of the tape cassette so that the test strip is wound forward and the plurality of functional elements stored thereon are made available for successive use,

The test strip is stopped in the functional position of the functional element by means of an automatic locking device acting on the transport mechanism.

Again, reference is made to the previous explanations regarding the advantageous effects of such a method.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is further explained below with reference to examples of embodiment schematically shown in the accompanying drawings, in which:

FIG1 is a top view of a cartridge-type blood glucose meter with a test strip transport mechanism including a manually operated actuator;

FIG2 is a block diagram of a blood glucose meter;

Figure 3 is a schematic diagram of a stopping device acting on the belt conveyor mechanism;

FIG4 is a more detailed top view of the belt transport mechanism cooperating with the stop device in the initial position;

FIG5 is an expanded view of FIG4;

Figures 6 to 8 show successive positions following the initial position shown in Figure 4;

9 is a top view of a section of a test strip.

DETAILED DESCRIPTION

The accompanying drawings show a medical instrument configured as a portable blood glucose meter 10, which is used for self-monitoring of blood glucose and includes a housing 12 and a conveying mechanism 18, wherein the housing 12 has a cartridge compartment 14 defining a space for inserting a disposable tape cartridge 16, and the conveying mechanism 18 is used to rotate the tape shaft 20 of the tape cartridge 16 so that the analytical test tape 22 of the cartridge can be wound forward and the functional elements 24 stored thereon can be sequentially provided for use, in particular for application and research of blood samples.

As shown in Figure 1, the transport mechanism 18 includes a manual drive 26, as depicted by the double arrow 28, which can be manually operated by the user in a bidirectional motion. The system including the tape cassette 16 can also be equipped with a lancing aid 30, allowing the user to draw fresh whole blood on the spot and apply the sample to the application tip of the cassette 16. The on-board photometric detection of the analyte (glucose) is known in the art and does not require further detailed explanation. The test results can be quickly provided on the display 32. The tape spool 20 is intended for removing or rolling up the used section of the test strip 22, while the reservoir 32 preferably protects the unused strip on the unrolled spool. Therefore, the flexible test strip 22 is transported only by the rotation of the spool 20, making it possible to avoid transport holes in the thin tape foil.

2 further illustrates the instrument 10, which includes a stop device 34 that acts on the transport mechanism 18 to achieve a targeted stop of the test strip 22 in a functional position, for example, when a functional element 24 in the form of a reactive test zone is placed on the tip of the cassette 16. The stop device 34 includes a position detection unit 36, which scans the test strip 22 during transport, and a locking unit 38, which can be actuated by a trigger signal 40 of the position detection unit 36 for mechanical blocking of the transport mechanism 18. For this purpose, the transport mechanism 18 includes a rotation unit 42, for example a gear, which is directly coupled to the tape shaft 20 via a connecting journal 44 when the tape cassette 20 is inserted into the housing 12.

In a practical embodiment, as explained in more detail further below, the position detection unit 36 has an optical sensor 46 to detect the position markings on the test strip 22. In addition, the position detection unit 36 can be connected to the display 32 to give the user position feedback. In a very simple arrangement, such feedback can be intended to cause the user to stop operating the manual drive 26, thereby causing the user to act on the transport mechanism 18.

FIG3 illustrates the function of the locking unit 38 of the stopper 34. The gear 42 directly drives the spool 20 of the tape cassette 16. The locking unit 38 includes a solenoid-operated actuator 48 and a return spring 50 to provide a locking force via a latch 52, which engages the teeth 54 of the gear 42. In the unlocked state, the solenoid coil 56 is energized and the solenoid core 58 is retracted (to the left in FIG3). At the same time, the return spring 50 is biased or extended, and the latch 52 is no longer engaged, thereby allowing the gear 42 to rotate. Upon receiving the trigger signal 40, the coil 56 is de-energized and the core 58 is pulled out (to the right in FIG3) under the action of the restoring force of the retracted return spring 50. When the rod 60 is connected to the actuator 48 and the spring 50 is tilted, the latch 52 locks against the teeth 52 and prevents further movement of the gear 42.

It is desirable to allow the user to feel the appropriate rotational speed when operating the manual actuator. In a very simple embodiment, the gear 42 shown in FIG3 can form a dial for direct manual rotation. Then, a marking spring 62 on the gear 42 can provide the user with a tactile signal or feedback indicating the current number of revolutions or rotational speed.

4 shows a manual drive 26 comprising a push rod 64 which is rotatably mounted on a rotary bearing 66 and can be manually operated by means of a handle 68. The push rod 64 has an arcuate toothed section 70 and a toothless cover section 72 towards its free end.

As can be seen from FIG5 , a rotatable pinion 74 is mounted in the movement path of the push rod 64 so that it can be rotated by the toothed section 70. The pinion 74 is connected to a freewheel assembly 76 in a rotationally fixed manner. The freewheel assembly 76 has a polygonal freewheel body 78, which has two rotatably mounted pawls 80 at opposite ends. The pawls are spring-loaded against the inner asymmetrical sawtooth profile of the gear 42, which can be connected to the belt shaft 20 as explained above.

During manual operation, when handle 68 is pushed inwardly toward housing 12, pinion 74 eventually engages toothed section 70 and translates the movement of push rod 64 into a counterclockwise rotation of body 78. Pawl 80 will then catch the steeply inclined first inner edge 80 of gear 42, thereby locking it for cooperative movement with freewheel body 78. However, when push rod 64 is pivoted in the opposite direction (outwardly), freewheel body 78 rotates in a clockwise direction and pawl 80 can easily slide upwardly over slightly inclined chamfer 84 of gear 42, thereby allowing free rotation of assembly 76 without actuation of gear 42.

Now referring back to FIG. 4 , the locking unit 38 of the locking device 34 is shown with a similar arrangement to that already explained above. The solenoid-operated actuator 48 is connected at its core 58 to a return spring 50, which is extended in its initial state. The latch 52 is formed as a two-armed lever, which is rotatably mounted on a rotary bearing 86. In the initial state, the latch 52 does not engage the teeth 54 of the gear 42.

In order to secure this initial state independently of the current supply state of the solenoid coil 56, the latch 52 is connected to the push rod 68 of the manual actuator 26 by means of an L-shaped control arm 88. This arm 88 is supported at its shorter bracket by means of a support pin 90 protruding from the side of the push rod 64. As a result, the restoring force of the return spring 50 can be maintained solely by mechanical means without current consumption in the coil 56.

As is apparent from FIG6 , during the initial phase of manual operation of the push rod 64, the toothless cover section 72 moves past the pinion 74 without engaging it, allowing the control arm 88 to be cleared from the support pin 90. At this stage, the solenoid-operated actuator 48 should already be energized to prevent undesired blocking of the gear 42. Current supply can be achieved via a switch (not shown) actuated by the push rod 64. Upon further movement of the push rod 64, the gear 42 is rotated via the toothed section 70, and the test strip is advanced via the strip shaft 20.

7 shows the blocking state, in which the locking unit 38 has received the trigger signal and closed the solenoid-operated actuator 48. The return spring 50 then contracts, thereby pulling the core 58 out of the coil 56 and the latch 52 pivoting into the blocking state, where it engages the teeth 54 of the gear 42. The test strip 22 is thus stopped in the functional position.

FIG8 shows the return position, in which push rod 64 has been rotated back (outward from housing 12) under the influence of a torsion spring, which may be arranged in bearing 66. When the user releases handle 68, this movement occurs automatically, but only to a certain angular distance at which support pin 90 catches control arm 90 in the center of the short bracket. Then, to reach the initial position shown in FIG4, the user must actively rotate handle 68 outward, thereby deploying return spring 50, core 58 moving back, and latch 52 being secured by control arm 88 supported on pin 90.

Figure 9 illustrates a test strip 22 having a series of segments 92 (e.g., 50 segments 92 in total), each of which is used for a single measurement. Bodily fluid is supplied to an analytical test zone 94 and analyzed using an optical measuring unit 95 of the instrument 10 in its predetermined functional (measuring) position. Furthermore, a calibration zone 96 is provided in each segment 92, which, when properly aligned, can be used to calibrate the measuring unit 95. To ensure targeted positioning of the test strip 22, each segment 92 includes a position marking 98 that can be detected by the optical sensor 46 of the position detection unit 36. Obviously, the tape travel distance varies to facilitate access to the different functional positions of the functional element 24, namely, the test zone 94 and the calibration zone 96. Furthermore, the diameter of the tape wound on the tape spool 20 increases with increasing test usage. These difficulties can be overcome through the coordinated action of the stop device 34 and the manual actuator 26.

Claims (36)

1. A handheld medical device for analyzing body fluids, comprising: a) Housing (12) having a compartment (14) constructed to receive a replaceable box (16). b) A conveying mechanism (18) comprising a manually operated manual drive that can be actuated by a user to rotate the belt shaft (20) of the tape cassette (16), wherein the test tape (22) of the tape cassette (16) is wound forward and provides functional elements (24) stored thereon for continuous use. Its features are, c) A stop device (34) acting on the conveying mechanism (18) and designed to stop the test strip (22) in the functional position of the functional element (24), wherein the stop device (34) has a locking unit (38) actuated to mechanically block the conveying mechanism (18). The conveying mechanism (18) has a gear (42) that can be rotated by the manual drive and can be blocked by the stop device (34), and wherein when the belt cassette (16) is inserted into the cassette compartment (14), the gear (42) is directly connected to the belt shaft (20) via the connecting journal (44). 2. The medical instrument according to claim 1, wherein the stop device (34) has a position detection unit (36). 3. The medical instrument according to claim 2, wherein the position detection unit (36) includes a non-contact scanning sensor (46) adapted to detect the functional position of a functional element (24) disposed on the test strip (22). 4. The medical instrument according to claim 1, wherein the stop device (34) has an optical sensor (46) adapted to detect a position mark (98) on the test band (22) and to provide a trigger signal to stop the test band (22). 5. The medical device according to claim 1, wherein the stop device (34) has a solenoid-operated locking actuator (48) and a return spring (50) to provide a locking force against rotation of the shaft (20) when the locking actuator (48) is released. 6. The medical device according to claim 1, wherein the stop device (34) has a control arm (88) connected to the manual actuator to prevent obstruction of the transmission mechanism (18) during the initial transmission phase. 7. The medical instrument according to claim 1, wherein when the transmission mechanism (18) reaches the functional position, it can be switched to an idle state by means of the stop device (34). 8. The medical device according to claim 1, wherein the stop device (34) has a position indicator unit (32) for providing a perceptible visual, auditory or tactile indication to the user to stop the actuation of the manual actuator. 9. The medical device according to claim 1, wherein the manual actuator comprises a rotary-mounted or linearly guided push rod (64) and a pinion (74), the push rod (64) being operable by a user, and the pinion (74) engaging teeth (70) on the push rod (64) and converting the motion of the push rod (64) into rotational motion to rotate the belt shaft (20). 10. The medical device according to claim 1, wherein the transmission mechanism (18) has a freewheel assembly (76) that allows rotational motion to be transferred to the belt shaft (20) in only one direction while preventing motion in the opposite direction. 11. The medical device according to claim 1, wherein the transmission mechanism (18) has a speed indication unit (62) for providing the user with a perceptible visual, auditory or tactile signal to indicate the rotational speed of the belt shaft (20). 12. The medical instrument according to claim 1, wherein the transmission mechanism (18) comprises an electric generator and an electric motor, the electric generator being operable by the manual drive. 13. The medical device of claim 12, wherein the electric motor is supplied with energy from a generator via a supercapacitor serving as a storage device. 14. The medical device according to claim 1, wherein the transmission mechanism (18) includes a storage device for storing mechanical energy. 15. The medical instrument according to claim 14, wherein the storage device for storing mechanical energy is a spring capable of being loaded by the manual actuator to automatically rotate the belt shaft (20) in a transmission cycle. 16. The medical device according to claim 1, wherein it is used for blood glucose testing. 17. The medical device according to any one of claims 1 to 16, wherein the test band (22) has continuous band segments (92), each of which includes a functional element shaped as a test area (94) for application of body fluids and at least one additional functional element (96), specifically the at least one additional functional element (96) being a calibration area, and wherein different band delivery distances are required to reach the respective functional positions of the functional elements (24) in each band segment (92). 18. A handheld medical device for analyzing body fluids, comprising: a) Housing (12) having a compartment (14) constructed to receive a replaceable box (16). b) A conveying mechanism (18) comprising a manually operated manual drive that can be actuated by a user to rotate the belt shaft (20) of the tape cassette (16), wherein the test tape (22) of the tape cassette (16) is wound forward and provides functional elements (24) stored thereon for continuous use. Its features are, c) A stop device (34) acting on the conveying mechanism (18) and designed to stop the test strip (22) in the functional position of the functional element (24), wherein the stop device (34) has a locking unit (38) actuated to mechanically block the conveying mechanism (18). The stop device (34) has a control arm (88) connected to the manual drive to prevent obstruction of the transmission mechanism (18) during the initial transmission phase. 19. The medical device according to claim 18, wherein the stop device (34) has a position detection unit (36). 20. The medical instrument according to claim 19, wherein the position detection unit (36) includes a non-contact scanning sensor (46) adapted to detect the functional position of a functional element (24) disposed on the test strip (22). 21. The medical instrument according to claim 18, wherein the stop device (34) has an optical sensor (46) adapted to detect a position mark (98) on the test band (22) and to provide a trigger signal to stop the test band (22). 22. The medical device according to claim 18, wherein the stop device (34) has a solenoid-operated locking actuator (48) and a return spring (50) to provide a locking force against rotation of the shaft (20) when the locking actuator (48) is released. 23. The medical device according to claim 18, wherein when the transmission mechanism (18) reaches the functional position, it can be switched to an idle state by means of the stop device (34). 24. The medical device according to claim 18, wherein the stop device (34) has a position indicator unit (32) for providing a perceptible visual, auditory or tactile indication to the user to stop the actuation of the manual actuator. 25. The medical device of claim 18, wherein the manual actuator comprises a rotary-mounted or linearly guided push rod (64) and a pinion (74), the push rod (64) being operable by a user, and the pinion (74) engaging teeth (70) on the push rod (64) and converting the motion of the push rod (64) into rotational motion to rotate the belt shaft (20). 26. The medical device according to claim 18, wherein the transmission mechanism (18) has a freewheel assembly (76) that allows rotational motion to be transferred to the belt shaft (20) in only one direction while preventing motion in the opposite direction. 27. The medical device according to claim 18, wherein the transmission mechanism (18) has a speed indication unit (62) for providing the user with a perceptible visual, auditory or tactile signal to indicate the rotational speed of the belt shaft (20). 28. The medical instrument according to claim 18, wherein the transmission mechanism (18) comprises an electric generator and an electric motor, the electric generator being operable by the manual drive. 29. The medical device of claim 28, wherein the electric motor is supplied with energy from a generator via a supercapacitor serving as a storage device. 30. The medical device according to claim 18, wherein the transmission mechanism (18) includes a storage device for storing mechanical energy. 31. The medical instrument according to claim 30, wherein the storage device for storing mechanical energy is a spring that can be loaded by the manual drive to automatically rotate the belt shaft (20) in the transmission cycle. 32. The medical device according to claim 18, wherein it is used for blood glucose testing. 33. The medical device according to any one of claims 18 to 32, wherein the test band (22) has continuous band segments (92), each of which includes a functional element shaped as a test area (94) for the application of body fluids and at least one additional functional element (96), specifically the at least one additional functional element (96) being a calibration area, and wherein different band delivery distances are required to reach the respective functional positions of the functional elements (24) in each band segment (92). 34. A medical system for analyzing bodily fluids, comprising a cartridge (16) including a test strip (22) and a handheld medical instrument according to any one of claims 1 to 33, the instrument comprising: a) A housing (12) having a compartment (14) configured to receive the box (16). b) A conveying mechanism (18) comprising a manual drive that can be actuated by a user to rotate the belt shaft (20) of the tape cassette (16), causing the test tape (22) to wind forward and providing functional elements (24) stored thereon for continuous use. Its features are, c) A stop device (34) that acts on the conveying mechanism (18) and is designed to stop the test strip (22) in the functional position of the functional element (24) provided on the test strip (22). 35. The medical system of claim 34, wherein it is used for blood glucose testing. 36. A method for operating a medical instrument according to any one of claims 1 to 33, comprising the following steps: a) Insert the replaceable tape cassette (16) including the test tape (22) into the compartment (14) located in the housing (12) of the instrument. b) A manual drive for actuating the conveyor mechanism (18) to rotate the belt shaft (20) of the tape cassette (16) so that the test tape (22) is wound forward and provides the functional elements stored thereon for continuous use. Its features are, c) The test belt (22) is stopped in the functional position of the functional element (24) by means of an automatic stop device (34) acting on the conveying mechanism (18).