US20060240403A1 - Tape magazine for a hand-held device - Google Patents

Abstract

The present invention concerns a tape magazine especially for a hand-held device for analysing a body fluid with a test tape that can be unwound from a storage unit and wound onto a waste unit where the waste unit can be driven in order to wind forward the test tape. The invention provides that a lock which keeps the test tape under tension is integrated in the tape magazine at least on the storage unit. The present invention also concerns a hand-held device with such a tape magazine. The present invention also concerns a hand-held device with a mechanical drive for the test tape and a disposable hand-held device with polymer-based electronic components.

Description

REFERENCE TO RELATED APPLICATIONS
• The present application claims priority toGerman Patent Application 10 2005 013 685.0 which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
• The invention The invention concerns a tape magazine for a hand-held device for examining a body fluid comprising a test tape, a storage unit for unused test tape and a waste unit for used test tape where the waste unit is driven in order to wind forward the test tape.
BACKGROUND
• In such tape magazines an unused section of test tape is pulled from a supply reel and guided over a receiving device where it takes up a sample of body fluid. Afterwards the section of test tape which is now used is wound onto a waste reel. A detection device which measures the sample and transfers the result of the measurement to an evaluation device is attached to the receiving unit.
• Such tape magazines are preferably used in blood sugar measuring instruments for diabetics who depend on a continuous monitoring of their blood sugar values. The test tape allows a blood sugar test to be carried out inside the instrument after applying capillary blood for example from a finger pad. For this purpose a plurality of test sections or test fields are arranged consecutively on the test tape. An unused section of tape is moved into an active position by advancing the tape. Then the capillary blood is applied and analysed. In order to simply dose very small amounts of blood and to position the test tape as exactly as possible relative to the detection device, the test tape is guided over a deflecting head inside the instrument. In this process there is a risk of erroneous measurements if the test tape slips off the deflecting head. For a successful measurement the test tape must remain at a well-defined position and rest against it evenly while maintaining a predetermined distance to the detection unit. This is necessary for at least as long as it takes to complete the measurement. Another challenge is that the test tape is very sensitive to contamination. Hence the unused area of the test tape should be spatially separated from the used area and also be screened from external influences which could impair the function of the test tape. Hence a direct drive coupling between the storage unit and the waste unit is very difficult.
• Furthermore the hand-held devices of the prior art are designed for continuous use whereas the tape magazine is replaced. The hand-held devices are therefore relatively large and quite laborious to manufacture not least due to the complicated instrument technology.
SUMMARY
• Hence an embodiment of the present invention is formed to provide a tape magazine which prevents malfunctioning due to slack tape.
• An embodiment of the present invention is further is formed to provide a hand-held device which is compact and has a favourable design for manufacturing.
• The combination of features stated in each of the independent patent claims is proposed. Embodiments and further developments of the invention are derived from the dependent claims.
• The present invention provides a tape magazine apparatus for a hand-held device for analysing a body fluid. The apparatus comprises a test tape, a storage unit formed for unused test tape, a waste unit formed for used test tape and to be driven in order to move forward the test tape from the storage unit, and an integrated brake that is formed to hold the test tape under tension between the storage and waste units.
• The present invention provides a tape magazine apparatus for analysing a body fluid comprising. The apparatus comprises a test tape, a reel body for unused test tape and a reel body for used test tape, at least one reel body being driven in order to forward the test tape, and a hand-operated transport mechanism provided as a tape drive.
• The present invention further provides a hand-held device for analysing a body fluid. The device comprises a tape magazine, an analytical test tape located in the tape magazine, and device electronics based upon integrated polymer circuits.
• Further, the present invention provides a method of dispensing a test tape for an analysis of body fluid. The method comprises providing a test magazine including a test tape, a storage unit formed for unused test tape, a waste unit formed for used test tape and to be driven in order to move forward the test tape from the storage unit, and an integrated brake, applying a brake force with the integrated brake to hold the test tape under tension between the storage and waste units, and actuating the test tape with a tensile force sufficient to move the test tape from the storage unit toward the waste unit.
• Accordingly it is proposed that a brake that holds the test tape under tension is integrated into the tape magazine. This enables the required minimum tape tension to be maintained since the waste unit drive transports the test tape against this tension so that it is not pulled too far away from the storage unit or unintentionally wound off. This allows the test tape to be deflected at a well-defined position relative to the detection unit. In this process the minimum tape tension also prevents unintentional lateral displacement. The tape drive force should in any case be of a sufficient magnitude to overcome the effect of the braking means.
• In particular, a braking force is applied to the storage unit which keeps the test tape under tension. This in particular prevents used test tape from being unintentionally wound off towards the application site. It also prevents areas of the test tape that have already been contaminated with blood from being pulled out of the tape magazine again which is an important hygienic advantage.
• The braking means can exert a braking force directly on the test tape. Alternatively the braking means can act on a reel body for the test tape such that the test tape is indirectly braked. In the latter case no allowance has to be made for changes in the diameter of the tape spool. Furthermore, this does not apply additional mechanical stress to the test tape.
• A simple embodiment provides that the braking means exert a constant braking force on the storage unit. This can be achieved by designing the braking means as a frictional element which in particular have a leaf spring as a frictional element. The braking means are formed by a seal which seals the storage unit at an opening for the test tape.
• In a somewhat more elaborate embodiment the braking means act on the storage unit with a variable braking force. This enables the force required to pull out the test tape to increase to a lesser extent as the diameter of the supply spool decreases compared to the simple embodiment described above. In this connection it should be taken into consideration that the supply spool has a certain bearing friction which has to be overcome by the drive. Accordingly it is necessary to apply a torque which results from the momentary radius of the waste spool and the applied force to reel off the tape from the supply spool. Thus when the radius of the supply spool decreases with time, this force must increase. If the braking force decreases as a function of the tape tension, the overall increase in force can be kept lower.
• An embodiment provides that the braking means have a deflector lever which is loaded with a braking force via a spring where the deflector lever deflects the test tape over a roller. As the tape tensile force decreases the deflector lever is unloaded. The deflector lever can for example be loaded with a leaf spring or pressure spring to exert the braking force and acts as a brake on a spool housing for the test tape.
• Another improvement envisages that the braking force is not only modulated by the tape tension but also by the current spool diameter with the aid of a compensation mechanism so that the tape tension remains almost constant.
• This object can be achieved with a compensation mechanism which has a spring-loaded rocker arm which probes the circumference of the tape spool wherein the spring loading decreases as the diameter of the tape spool decreases and the braking force is correspondingly reduced. Hence the tape tensile force remains constant.
• In another embodiment a recoil locking device or recoil brake which acts in a form-fitting or frictional manner can be provided on the waste unit. If a recoil locking device is used as a locking mechanism, the drive for forwarding the test tape only has to overcome the friction of the storage unit which in particular spares the battery of the drive. This recoil safeguard should not act on the tape drive so that it is also effective when the tape magazine is removed from the hand-held device and prevents used tape from being unintentionally reeled out. The recoil locking device can be designed in a known manner as a safety catch which engages in gear teeth for example in the spool housing of the waste unit in such a manner that a form fit in the reverse direction prevents the waste unit from turning back. The waste unit is then restricted to the “wind on” direction of rotation. However, a frictional locking mechanism can also be provided. Various mechanisms are conceivable for this for example a wrap spring lock or a clamp roller free-wheel.
• The tape magazine has a housing which encloses the test tape, the storage unit and the waste unit. The storage unit should be accommodated in a storage space that is screened from influences that could impair the test tape. This can for example be achieved by a wall of the storage space forming an overlapping area with a wall of the housing with an opening for the test tape being formed along the overlapping area. This opening should be provided with at least one sealing agent or with one sealing means in order to protect the test tape from external influences.
• The present invention also concerns a tape magazine for a test tape in which a hand-operated transport mechanism is provided as a tape drive. An actuating lever is provided for this which engages in an advancing element (e.g. capstan or index wheel) via a feed member, in particular a pawl, in such a manner that the test tape can be moved mechanically. A battery power supply is thus unnecessary. The energy required for the actual measuring process can be generated by the manual actuation and especially by means of an inductive generator or piezoelectrically and for example stored temporarily in a capacitor or high-performance capacitor (supercap). The tape magazine also forms a hand-held device intended as a single-use article, a so-called disposable, which can be discarded after the test tape has been used due to the cost-effective construction.
• The feed mechanism can for example be formed by a ratchet which engages in steps formed in the storage unit and/or waste unit. Such a construction is robust and simple to operate.
• The test tape feed is synchronized by a perforation in such a manner that a test element is ready for a measurement when the lever is actuated at least once so that the measurement can be carried out particularly reliably and with great accuracy. Reference fields can be provided on the tape to further improve the feed accuracy.
• Finally the present invention concerns a hand-held device which is directly formed by a tape mechanism and has instrument electronics, in particular a sensor unit, an evaluation unit and a display unit based on polymer electronics. Such a hand-held device can be constructed to be small and light, can be manufactured cost-effectively and can be used as a disposable unit.
• In particular all disclosed embodiments of tape magazines and hand-held devices can be combined with one another. This applies especially to a hand-held device with electronic components based on polymer electronics combined with a mechanical drive for the test tape.
• The invention is elucidated in more detail in the following on the basis of the embodiment examples shown in a schematic manner in the drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 shows a first embodiment example of a tape magazine according to the invention in cross-section.
• FIG. 2 shows a second embodiment example of a tape magazine according to the invention in a side-view in a partial cross-section.
• FIG. 3 shows a third embodiment example of a tape magazine according to the invention in a side-view in a partial cross-section.
• FIG. 4 shows an embodiment example of a mechanically operated tape device in a perspective view with a partially opened housing.
• FIG. 5 shows the device according toFIG. 4 with a closed housing.
DETAILED DESCRIPTION
• FIGS.1 to3 show various embodiment examples of a tape magazine according to the invention in which the test tape is held under tensile strain.FIG. 1 shows atape magazine10 with ahousing11. Thehousing11 is divided into afirst holder12 for astorage unit20 and asecond holder13 for awaste unit24. Theholders12,13 are separated from one another by a dividingwall14 so that thestorage unit20 is separated from thewaste unit24. Oneside wall12a,13aof each of theholders12,13 overlaps in thearea19 to form anopening16 which is provided with aseal17. Theseal17 can act as a brake, sealing thestorage unit20 at theopening16 for thetest tape30. Anotheropening15 is provided in theholder13 for thewaste unit24. Adeflector head18 for thetest tape30 is integrated into thehousing10.
• Thestorage unit20 has a spool or reelhousing21 which holds anunused test tape30 which is wound around aspool22 to form asupply spool23. Thewaste unit24 is similarly equipped with aspool housing25 which holds the used test tape wound onto aspool26 to form awaste spool27. Thespool26 is driven by a drive (not shown). Thetest tape30 is divided into consecutive test areas. If the drive is actuated, thefresh test tape30 is wound off thesupply spool23 and guided from theholder12 through theopening16 to thedeflector head18 where a single test area comes to rest exposed to the outside and can take up a test liquid such as a drop of blood. The test liquid is measured by a detection unit (not shown). When the drive is actuated again thetest tape30 is transported further. The usedtest tape30 passes through theopening15 into theholder13 and is wound onto thewaste spool27.
• An integrated brake is formed to hold thetest tape30 under tension between the storage andwaste units20,24. It is within the scope of the present invention that the brake be formed to apply a force to thestorage unit20, to exert a direct braking force on thetest tape30; to act on areel body21 for thetest tape30 such that the test tape is indirectly braked, or to exert a constant braking force on thestorage unit20. It is further appreciated that it is within the scope of the present invention that the brake is designed as a frictional element.
• It is further appreciated that the brake may be formed to act on the storage unit with a variable braking force in accordance with this disclosure. In such an instance, the variable braking force may depend on the diameter of a tape spool of thestorage unit20. Alternatively, the variable braking force may depend on the tape tensile force upon movement of thetest tape30.
• In an embodiment shown inFIG. 1, the brake is aleaf spring28 as a frictional element which acts upon thecontact point29 of thespool housing21. Thespring28 is provided on an inner wall of theholder12 for thestorage unit20. Theleaf spring28 is pretensioned with a constant spring force F_spring. Therefore, thetest tape30 has to be reeled off against the corresponding brake torque at a certain tape tensile force F_tape. This tape tensile force increases as the radius of thesupply spool23 decreases.
• FIGS. 2 and 3 show two further embodiment examples of atape magazine40,50 according to the invention which only differ from theaforementioned tape magazine10 with regard to the design of the brake. Hence identical components are labelled with the same reference numerals.
• Thetape magazine40 shown inFIG. 2 also has aleaf spring41 on an inner wall of theholder12 below the dividingwall14 which is pretensioned with a constant spring force F_spring. In addition a rockinglever43 is hinged around oneaxis44 on the inner wall of theholder12. The free end of the rockinglever43 is provided with a rotating deflector roller over which thetest tape30 is guided. The rockinglever43 is arranged between theleaf spring41 and thespool housing21 and extends tangentially to thespool housing21. The rockinglever43 touches theleaf spring41 at acontact point42 and thespool housing21 at acontact point45. A constant spring force F_springis applied to the rockinglever43 by theleaf spring41. Consequently a corresponding force is also applied to thespool housing21 by the rockinglever43.
• When the drive for thetest tape30 is actuated, it has to be reeled off at a certain tape tensile force F_tapeagainst the brake torque acting on thespool housing21. The tape tensile force acts upon the long lever arm of the rockinglever43 via thedeflector roller46 and relieves thecontact point45 depending on the tape tensile force. Hence a lower tape tensile force has to be applied to reel off the test tape than in the case of the embodiment example shown inFIG. 1 as the diameter of thesupply spool23 decreases.
• The embodiment example shown inFIG. 3 of atape magazine50 is formed to include a compensation mechanism that is loaded with a force that changes depending on the diameter of a tape spool of the storage unit.Tape magazine50 has a rockinglever51 on the inner wall of theholder12 below the dividingwall14 which is hinged on the inner wall around anaxis52. The free end of the rockinglever43 is also provided with a rotating deflector roller53 over which thetest tape30 is guided. The rockinglever51 also extends tangentially to thespool housing21 and touches thespool housing21 at a contact point that is not visible in the figure.
• The compensation mechanism is formed by a rocker arm54 that can rotate around anaxis55 is pivoted on the rockinglever51. The free end of the rocker arm54 is provided with a follower roller56 which rests on the circumference of thesupply spool23 at a contact point58. Apressure spring57 which is pretensioned with a certain spring force F_springis braced against the dividingwall14 and the rocker arm54 such that this spring force is applied to the rocker arm54.
• When the drive for thetest tape30 is actuated, it has to be reeled off with a certain tape tensile force F_tapeagainst the brake torque acting on thespool housing21. This tape tensile force acts upon the long lever arm of the rockinglever43 and relieves the contact point between the rockinglever51 and thespool housing21 depending on the tape tensile force. At the same time the follower roller56 of the rocker arm54 runs on the circumference of thesupply spool23. As the radius of thesupply spool23 decreases, the follower roller56 travels towards thespool22 so that thepressure spring57 relaxes as the radius of thesupply spool23 decreases. Thus the contact point between the rockinglever51 and thespool housing21 is relieved as a function of the radius of thesupply spool23. As a result the tape tensile force F_tapethat has to be applied by the drive remains constant as the radius of thesupply spool23 decreases.
• FIGS. 4 and 5 show a combination of a hand-held device with polymer-based electronic components and a mechanical drive for the test tape.
• The hand-helddevice100 is a single-use device, a so-called disposable. It has ahousing101 made of plastic in which tworeel bodies102,103 are located. Atest tape104 with consecutive test fields is wound onto thereel bodies102,103. In an embodiment, device electronics are provided that are based upon integrated polymer circuits (IPC). A non-limiting example of which includes a photo-optic sensor105 provided in thehousing101 in spatial vicinity to ameasuring site106. At the measuringsite106 thetest tape104 is accessible from outside in order to take up a sample liquid such as blood for a blood sugar determination. The area between the emitter and receiver of the sensor and the test tape can be bridged by an optical path or light guide. The measured value recorded by thesensor105 is transferred to anevaluation unit109. Here a display value such as the blood sugar content is calculated.
• The photo-optical sensor consists of at least one light-emitting diode (LED) of a suitable wavelength, particularly an organic light-emitting diode (OLED), combined with one or more organic photodiodes (multi-photometer principle). LEDs of multiple wavelengths are also conceivable. It is further conceivable that the device may include an electrochemical detection system. In an embodiment, it is appreciated that the electrochemical sensor components are mounted on thetest tape104 and are connected to the device electronics at a measuring position.
• Theevaluation unit109 comprises for example an amplifier, analog/digital (AD) converter, calculator, control mechanism, data store, energy supply and interfaces, and is connected to adisplay unit110 which shows the determined display value on a display. The display unit can be designed in a known manner such that a display can be maintained until the next measuring process even without an energy supply for example by using so-called “electronic inks”.
• The data store in the evaluation unit can consist of a read-only memory (ROM) or electrically erasable programmable read-only memory (EEPROM). It is mainly required to store batch-specific data which are determined during the manufacture of the disposables and are deposited thereon. Data transfer occurs by means of contact interfaces or radio-frequency identification (RF-ID) transponders. An electronic test field counter can also be realized using an EEPROM.
• The electronic components of this hand-held instrument are known polymer-electronic components. Such components are described in for example in CA 2516490 A1 2004/05/27 the contents thereof being herewith incorporated into the disclosure of the present patent application. The use of such components enables all necessary electronic components to be integrated into a magazine housing so that the resulting tape magazine also constitutes a fully functional and very convenient single-use hand-held device. Such a single-use hand-held device is small and light, cost-effective and easy to operate. It is not necessary to change the tape magazine. It leaves room for further miniaturization of portable hand-held devices. It also obviates the necessity for a complicated construction of interfaces between the tape magazine and hand-held device.
• All polymer-based electronic components can be printed in a known manner onto suitable mouldings of thehousing101 of the hand-heldinstrument100.
• The energy is supplied by high-performance capacitors (supercap) for example combined with solar cells/photovoltaic cells. Due to the low-energy density that can be achieved it is recommended to manually drive thespool bodies102,103 of the described disposable hand-held device.
• A transport mechanism is provided as a tape drive. For this purpose thereel bodies102,103 have teeth or steps. Afeed pawl107 which is only indicated here engages in these teeth or steps. Thefeed pawl107 is connected to alever108 provided on the outside of the housing. Thetest tape104 is fed by operating the lever. This moves thereel bodies102,103 exactly so far that a fresh test field of thetest tape104 is accessible from outside at the measuringsite106. In order to synchronize the movement of thereel bodies102,103 andtest tape104, the latter is perforated such that teeth arranged on thereel bodies102,103 (not shown) engage in the perforation. The test fields can also be spaced on the test tape in such a manner that a first operation of thelever108 makes a fresh test field accessible at the measuringsite106. A second operation of thelever108 moves the test field which is now used away from the measuringsite106 without a new test field immediately appearing. This only occurs when thelever108 is operated again.
• The operation of thelever108 can also generate in a known manner the energy of a few milliwatts required for the measurement which can for example be temporarily stored in a capacitor or supercap. A temporary mechanical store in the form of a spring can be provided to obtain energy by a generator or piezoelectrically which allows an adaptation to the various time constants.
• A particularly environmentally friendly design of the device can be achieved by refraining from an electrochemical energy store.

Claims (45)

1: Tape magazine apparatus for a hand-held device for analysing a body fluid, the apparatus comprising:

a test tape,

a storage unit formed for unused test tape,

a waste unit formed for used test tape and to be driven in order to move forward the test tape from the storage unit, and

an integrated brake that is formed to hold the test tape under tension between the storage and waste units.

2: The apparatus ofclaim 1 wherein the brake is formed to apply a force to the storage unit.

3: The apparatus ofclaim 1 wherein the brake is formed to exert a direct braking force on the test tape.

4: The apparatus ofclaim 1 wherein the brake is formed to act on a reel body for the test tape.

5: The apparatus ofclaim 1 wherein the brake is formed to exert a constant braking force on the storage unit.

6: The apparatus ofclaim 1 wherein the brake is formed as a frictional element.

7: The apparatus ofclaim 1 wherein the brake comprises a leaf spring.

8: The apparatus ofclaim 1 wherein the brake is formed by a seal at an opening of the storage unit for the test tape.

9: The apparatus ofclaim 1 wherein the brake is formed to act on the storage unit with a variable braking force.

10: The apparatus ofclaim 9 wherein variable braking force depends on the diameter of a tape spool of the storage unit.

11: The apparatus ofclaim 9 wherein the variable braking force depends on the tape tensile force upon movement of the test tape.

12: The apparatus ofclaim 9 wherein the brake has a lever loaded with a braking force via a spring.

13: The apparatus ofclaim 12 wherein the lever has a roller at one end and the test tape is deflected over the roller.

14: The apparatus ofclaim 9 wherein the brake has a compensation mechanism that is loaded with a force that changes depending on the diameter of a supply spool of the storage unit.

15: The apparatus ofclaim 14 wherein the compensation mechanism is formed by a spring-loaded rocker arm which touches the circumference of the supply spool.

16: The apparatus ofclaim 1 wherein the storage unit has a first housing wall and the waste unit has a second housing wall that forms an overlapping area with the first wall, the overlapping area defining an opening formed to carry through the test tape.

17: The apparatus ofclaim 16 wherein the integrated brake includes a seal positioned in the opening.

18: A hand-held device for analysing a body fluid with a replaceable tape magazine according toclaim 1.

19: A tape magazine apparatus for analysing a body fluid comprising:

a test tape,

a reel body for unused test tape and a reel body for used test tape, at least one reel body being driven in order to forward the test tape, and

a hand-operated transport mechanism provided as a tape drive.

20: The apparatus ofclaim 19, wherein the transport mechanism has a lever for the hand operation that is coupled to at least one reel body.

21: The apparatus ofclaim 19, wherein the transport mechanism has a ratchet that engages in steps or teeth formed in at least one reel body.

22: The apparatus ofclaim 19, wherein a test tape feed is synchronized by a perforation.

23: The apparatus ofclaim 19, wherein the transport mechanism is formed to convert mechanical into electrical energy in order to supply energy to a device electronics.

24: The apparatus ofclaim 19, wherein the magazine forms a hand-held single-use article.

25: A hand-held device for analysing a body fluid comprising

a tape magazine,

an analytical test tape located in the tape magazine, and

device electronics based upon integrated polymer circuits.

26: Hand-held device according toclaim 25, wherein the device electronics comprise a sensor unit, an evaluation unit and a display unit.

27: Hand-held device according toclaim 25, wherein the device electronics have a photo-optic detection system.

28: Hand-held device according toclaim 35, wherein the device electronics includes LEDs or an electrochemical detection system.

29: Hand-held device according toclaim 25, wherein the tape magazine includes a housing and at least a portion of the device electronics is applied to the housing.

30: Hand-held device according toclaim 29, wherein at least a portion of the device electronics is printed onto the housing.

31: Hand-held device according toclaim 25, wherein the device electronics comprise at least one storage capacitor.

32: Hand-held device according toclaim 25, wherein the device electronics comprise at least one storage element.

33: Hand-held device according toclaim 25, wherein the device electronics comprise photovoltaic cells.

34: Hand-held device according toclaim 25, wherein electrochemical sensor components are mounted on the test tape and are connected to the device electronics at a measuring position.

35: Hand-held device according toclaim 25, wherein the tape magazine together with the device electronics forms a disposable unit.

36: A method of dispensing a test tape for an analysis of body fluid, the method comprising:

providing a test magazine including a test tape, a storage unit formed for unused test tape, a waste unit formed for used test tape and to be driven in order to move forward the test tape from the storage unit, and an integrated brake,

applying a brake force with the integrated brake to hold the test tape under tension between the storage and waste units,

actuating the test tape with a tensile force sufficient to move the test tape from the storage unit toward the waste unit.

37: The method ofclaim 36 wherein the brake force is modulating so that the test tape tension remains generally constant during use of the test tape.

38: The method ofclaim 36 wherein the brake force is applied to the storage unit.

39: The method ofclaim 36 wherein brake force is applied directly on the test tape.

40: The method ofclaim 36 wherein the brake force acts on a reel body for the test tape.

41: The method ofclaim 36 wherein the brake is formed as a frictional element.

42: The method ofclaim 36 wherein the brake is a leaf spring.

43: The method ofclaim 36 wherein the brake is formed by a seal at an opening for the test tape.

44: The method ofclaim 36 wherein the brake force is variable and acts on the storage unit.

45: The method ofclaim 44 wherein the brake force depends on the diameter of a tape spool of the storage unit.

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