(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2010/0145377 A1
`LAI et al.
`(43) Pub. Date:
`Jun. 10, 2010
`
`US 20100145377A1
`
`(54) LANCING DEVICE FOR MINIMIZING PAIN
`
`Publication Classification
`
`(75) Inventors:
`
`(73) Assignee:
`
`Venture Corporation Limited
`Sin
`s
`gapore (SG)
`
`(51) Int. Cl.
`(2006.01)
`A6B 17/34
`Siew Kong LAI, Skudai (MY);
`(52) U.S. Cl. ......................................... 606/182: 606/181
`Chow Kian Yeo, Singapore (SG)
`(57)
`ABSTRACT
`Correspondence Address:
`The present invention provides a lancing device designed for
`LAWRENCE Y.D. HO & ASSOCATES PTE LTD
`30 BIDEFORD ROAD, #02-02, THONGSIA minimizing pain to the user, comprising a probe with cam
`BUILDING
`profile responsible for controlling the lancet speed such that
`SINGAPORE 22.9922 (SG)
`the lancet enters the skin relatively fast, decelerates smoothly
`and gradually to Zero Velocity at maximum depth of penetra
`tion and retracts slowly and controllably. The housing of the
`lancet comprises of leaf springs and set of guides for mini
`-
`0
`-
`mizing or eliminating pitching or vibration of the lancet dur
`ing lancing, hence reducing the pain experienced by the user.
`The lancing device is further equipped with a gear-damper
`system for minimizing or eliminating noise produced during
`lancing process.
`
`(21) Appl. No.:
`
`12/327,817
`
`(22) Filed:
`
`Dec. 4, 2008
`
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`LANCING DEVICE FOR MINIMIZING PAN
`
`FIELD OF THE INVENTION
`0001. The present invention generally relates to a lancing
`device, and in particular to a lancing device for minimizing
`pain to the user while withdrawing sample fluid.
`
`BACKGROUND OF THE INVENTION
`0002 Lancing device, or also called a lancet device, is
`typically used in the medical field to lance or break the surface
`of the skin of one's finger, in order to extract a small blood
`sample for self diagnostic purposes.
`0003 Good diabetes management requires frequent self
`monitoring of blood glucose level through self-testing. Lanc
`ing device is a critical tool for obtaining blood samples for
`glucose measurement. Self-testing of blood glucose is impor
`tant, as it enables people with diabetes to know their blood
`glucose level at any time, hence allowing them to exercise
`tighter blood glucose control. This will help to prevent any
`potentially serious consequences of very high or very low
`blood glucose level. It is especially crucial for people who
`take insulin, as self-testing will allow more accurate dosage
`adjustment.
`0004. The primary mechanism of most lancing devices
`currently existing in the market, both for repeated use and
`disposable lancet types, involved the priming of a spring
`based system, followed by a release of a trigger to launch the
`lancet or needle into the finger of the user. In this way, the
`lancet or needle is made to puncture a tiny hole on the finger
`of the user, for a blood sample to be extracted for diagnostic
`purposes.
`0005 Such lancing devices generally convert the potential
`energy from the primed spring into the kinetic energy of a
`moving lancet and its holder at the same time. This kinetic
`energy is then dissipated through the impact of the lancet and
`its holder against a rigid stop, which is also often used as a
`way of defining the depth of penetration of the needle into the
`user's finger. In most cases, the residual kinetic energy is
`used, to reverse the motion of the lancet, and hence extracting
`it from the finger after puncturing a hole in it.
`0006. It is quite typical to hear complaints from users of
`the lancing devices with design described above, in relation to
`pain during lancing process. This could be attributed to some
`of the following reasons. The lancing mechanism hitting at a
`hard stop at maximum velocity would cause excessive impact
`vibration, which will then be transmitted to the lancet. The
`excessive relative vibration and movement between needle
`and finger is likely the cause of the pain experienced by user.
`0007 Another cause of pain during lancing is an uncon
`trolled lancing motion of the lancet, which will result in an
`unpredictable trajectory of the needle during lancing process.
`This uncontrolled motion refers to the ability of the lancet and
`its holder to move within the sliding clearance offered by its
`guides, which are often plastic molded features. In addition to
`that, impact noise is perceived as pain most of the time, since
`it forms part of the overall user experience. Devices with such
`lancing mechanism, which relies on impact to define the
`lancet's penetration depth and to reverse its motion, are often
`perceived by the user as being noisy and painful.
`0008 Examples of lancet device with a design intended to
`allow less painful blood withdrawal, may be seen in the
`following U.S. Patents. U.S. Pat. No. 4.924,879 discloses a
`bloodlancet device, which convert the relaxation movement
`
`of the drive spring by means of a rotatable drive rotor into the
`prick movement, hence allowing blood withdrawal with little
`or no pain. The vibration caused by the impact of the lancet
`holder onto a hard stop can then be avoided. The rotor is
`driven by a coaxial coil spring and the rotation movement of
`the rotor is converted to the linear movement of the lancet by
`means of a push rod system.
`0009 U.S. Pat. No. 5,318,584 discloses a lancing device
`with the drive rotor having a rotation axis parallel to the prick
`direction and is also driven by a coaxial coil spring. The
`conversion of the rotational movement into the necessary
`linear movement of the lancet holder is performed by a rotary
`drive. The design allows a very good pricking behavior with
`low vibrations and a reproducible pricking depth, hence
`resulting in less pain. U.S. Pat. No. 4,203,446 discloses a
`spring lancet holder with improved accuracy and reproduc
`ibility of puncture wounds in the skins by minimizing the
`recoil transmitted to the lancet holder by actuation of the drive
`mechanism, which pushes the lancet into the skin.
`0010. However, these prior arts only reduced the extent of
`the above mentioned problem, as the basic working principle
`and mechanism of the lancing device remain unchanged, by
`making use of hard stop to stop an advancing lancetto achieve
`depth of penetration, resulting in kinetic energy being dissi
`pated through impact.
`
`SUMMARY OF THE INVENTION
`
`(0011. The following presents a simplified summary to
`provide a basic understanding of the present invention. This
`Summary is not an extensive overview of the invention and is
`not intended to identify key features of the invention. Rather,
`it is to present Some of the inventive concepts of this invention
`in a generalized form as a prelude to the detailed description
`that is to follow.
`0012. The present invention provides a lancing device for
`minimizing pain to the user while withdrawing sample fluid.
`According to one aspect of the invention, there is provided a
`lancing device comprises of a lancet, a housing comprising
`leaf springs and guides for minimizing or eliminating pitch
`ing or vibration of the lancet during lancing, a probe with cam
`profile responsible for controlling the lancet speed such that
`the lancet enters the skin relatively fast, decelerates smoothly
`and gradually to Zero Velocity at maximum depth of penetra
`tion and retracts slowly and controllably, a gear-damper sys
`tem for minimizing or eliminating noise produced during
`lancing process, and a priming System.
`0013. In one embodiment of the present invention, the
`guides comprise of v-shaped guides and profile guides, which
`are used together with the leaf springs for minimizing or
`eliminating probe movement in X- and y-axis during lancing
`process.
`0014. In another embodiment of the present invention, the
`probe with cam profile comprises of profile slides having its
`rotation centre coinciding with the lancet's rotation centre.
`0015. In yet another embodiment of the present invention,
`the probe with cam profile comprises of slotted guides for
`limiting rotational movement of the probe during lancing
`process.
`0016. In another embodiment of the present invention, the
`priming system comprises of a torsion spring, a probe actua
`tor, a priming gear, a rack, a priming button, a compression
`spring and a fire button.
`
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`US 2010/0145377 A1
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`Jun. 10, 2010
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`0017. In yet another embodiment of the present invention,
`the probe actuator comprises of an integrated damper and a
`cam follower.
`0018. The objectives and advantages of the present inven
`tion will become apparent from the following detailed
`description of embodiments thereof in connection with the
`accompanying drawings.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`0019 Preferred embodiments according to the present
`invention will now be described with reference to the figures
`accompanied herein, in which like reference numerals denote
`like elements.
`0020 FIG. 1 is a perspective view of a lancing device
`according to one embodiment of the present invention;
`0021
`FIG. 2 is a top perspective view of a top case of the
`lancing device in accordance with one embodiment of the
`present invention;
`0022 FIG.3 is an exploded bottom view of the top case of
`the lancing device in accordance with one embodiment of the
`present invention;
`0023 FIG. 4 is an exploded view of a bottom case of the
`lancing device in accordance with one embodiment of the
`present invention;
`0024 FIG. 5 is a top perspective view of a probe with cam
`profile of the lancing device in accordance with one embodi
`ment of the present invention;
`0025 FIG. 6 is a bottom perspective view of the probe
`with cam profile of the lancing device in accordance with one
`embodiment of the present invention;
`0026 FIGS. 7 a-b show lancet displacement profiles in Z-X
`and Z-y axes of the lancing device in accordance with one
`embodiment of the present invention and its competitor,
`0027 FIG. 8 is a top perspective view of a probe actuator
`of the lancing device in accordance with one embodiment of
`the present invention;
`0028 FIG. 9 is a bottom perspective view of the probe
`actuator of the lancing device in accordance with one embodi
`ment of the present invention;
`0029 FIG. 10 is a cross sectional view of a connection
`between the probe actuator and a bottom case of the lancing
`device in accordance with one embodiment of the present
`invention;
`0030 FIG. 11 is a top perspective view of a final assembly
`of the lancing device in accordance with one embodiment of
`the present invention.
`
`DETAILED DESCRIPTION OF THE INVENTION
`0031
`Description of certain embodiments of the present
`invention shall now be explained in detail, with reference to
`the attached drawings. It is to be understood that no limitation
`of the scope of the invention is thereby intended, such alter
`ations and further modifications in the illustrated device, and
`Such further applications of the principles of the invention as
`illustrated therein being contemplated as would normally
`occur to one skilled in the art to which the invention relates.
`0032 FIG. 1 shows a perspective view of a lancing device
`according to one embodiment of the present invention. In this
`embodiment of the present invention, a housing 2 of the lancet
`device 1 comprises of top case 3 and bottom case 4. Screws
`are used to hold the top case 3 and bottom case 4 together. In
`another embodiment of the present invention, the top case 3
`and bottom case 4 are joined together by ultrasonic welding.
`
`A cap 5 is disposed at the frontend of the housing 2, which has
`an opening 6 for exit and reentry of the lancet 7. The top 3 and
`bottom case 4 follows an oval shape for easy holding.
`0033 FIG. 2 shows a top perspective view of the layout of
`the top case assembly of the lancet device according to one
`embodiment of the present invention. A priming system
`employed in this embodiment comprises of a priming gear 11,
`a compression spring 12, a priming button 13, a rack 14, a
`probe actuator 15, a torsion spring 16 and a fire button 17.
`Details of the configuration of the priming system are further
`illustrated in FIG.4, which shows an exploded bottom view of
`the top case of the lancing device according to one embodi
`ment of the present invention. A case top cover 18 is needed
`to connect the priming gear 11 and the fire button 17 to the top
`case 3 via screws connection. The priming gear 11 is coupled
`to the rack 14 in such a way that the teeth 19 of the priming
`gear engage the teeth 20 of the rack.
`0034. The priming button 13 is connected to the rack 14
`via screws connection, as illustrated in FIG. 3. When the
`lancet user pulls the priming button 13 downward, the rack 14
`is then driven down to a stop position, thereby causing the
`priming gear 11 to rotate in counter-clockwise direction. The
`priming gear 11 is coupled to the probe actuator, such that the
`rotational motion applied to the priming gear 11 will then be
`used to prime the probe actuator 15. The probe actuator 15,
`together with the torsion spring 16 where the potential energy
`is stored, are then locked in the primed position and will only
`be released once the fire button 17 is pressed. Once the fire
`button 17 is pressed, the stored potential energy from the
`torsion spring 16 will then be imparted to the probe actuator
`15, resulting in the forward sliding of the probe 10 together
`with the lancet 7 towards the skin of the user. The compres
`sion spring 12 serves the function for returning the priming
`button 13 to the original position.
`0035) Details of the layout of the bottom case assembly of
`the lancet device according to one embodiment of the inven
`tion are illustrated in FIG. 4. The bottom case 4 also has a
`guide pin 21 projected out from the middle of the case. The
`guide pin 21 has a frame slot 22 for receiving and coupling
`with the probe actuator 15. Two V-shaped profile guides 23
`and 24 are disposed on the front and rear part of the bottom
`case 4 for locating a probe with cam profile 10. There are also
`two pin connections 25 located on one longer side surface 8 of
`the bottom case, for attachment of two leaf springs 26. The
`leaf springs 26 are used for Suspending the probe with cam
`profile 10 in the lancing device 1, such that the movement of
`the probe 10 in Z-axis is eliminated during sliding of the lancet
`7. In other words, the leaf springs 26 are used to ensure that
`the probe with cam profile 10 will always be in contact with
`the V-shaped profile guides 23 and 24 of the bottom case 4.
`This is done to minimize pitching of the lancet 7 during
`lancing, hence reducing the pain.
`0036 FIG.5 illustrates a perspective top view of the probe
`with cam profile 10 according to one embodiment of the
`present invention. There is an integrated lancet collar 27
`disposed at the front part of the probe 10. The lancet collar 27
`has a cutaway 28 for providing a gripping force to the lancet
`7. The cutaway 28 offers the flexibility to open up the lancet
`collar 27 after the lancet 7 is inserted. Hence, the lancet 7 can
`be easily removed and replaced accordingly. The probe 10 has
`an embedded cam profile 29 and a slotted opening 30 in the
`middle part for receiving the probe actuator 15there through.
`Two raised pads 31 for contacting leaf springs 26 are posi
`tioned before and after the slotted opening 30 respectively.
`
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`Jun. 10, 2010
`
`The probe 10 is further equipped with front 32 and rear 33
`profile slides. The contact surfaces of profile slides 32 and 33
`have circular profiles whose center axes coincide with that of
`the lancet center. This will limit the probe movement, if any,
`to a slight minimum rotation of the lancet, instead of lateral
`movement of the lancet, thus reducing any pain experienced
`by the user to a minimum. The front profile slides 23 are
`slightly larger than the rear profile slides 24. FIG. 6 shows a
`perspective bottom view of the probe with cam profile 10
`according to one embodiment of the present invention. There
`are slotted guides 34 in the front and rear part of the probe 10
`for limiting the rotational movement of the probe during
`lancing process.
`0037 Referring to FIG. 4 and FIG. 5, the cam profile 29 is
`molded into the probe 10 and is responsible for regulating the
`speed of the lancet 7. The velocity profile of the lancet 7 is
`controlled by the cam system. In other words, contouring the
`cam profile 29 would allow the related lancet displacement
`and Velocity profile to be optimized for minimum pain and
`enhanced user compliance. The lancet 7 penetrates the skin
`relatively fast but decelerates smoothly and gradually to Zero
`Velocity at the maximum depth of penetration into the target
`area, where the nerve endings are abundant. The Smooth
`transition to Zero velocity and absence of vibration reduces
`pain to the user. Slow and controlled retraction of the lancet
`will prevent the wound channel to collapse and allow the
`blood to flow directly to the surface. This feature encourages
`rapid healing of the puncture wound and offers less painful
`lancing experience to the user at the same time.
`0038 FIGS. 7 a-b show the comparison of the lancet dis
`placement in Z-X and Z-y axes during the lancing process,
`between the lancet device of the present invention (FIG. 7a)
`and a leading lancet product (FIG. 7b). The displacement
`profiles clearly show that there is minimum or no lateral
`movement of the lancet device of the present invention during
`the lancing process. The lancet of the present invention
`enhances controlled motion of the lancet for its entry and
`withdrawal from the skin of the user during the lancing pro
`cess, as shown by an almost straight line in its displacement
`profiles indicating little or no lateral movement of the lancet
`during its entire lancing trajectory. This feature allows the
`pain experienced by the user during lancing process to be
`reduced to the minimum level and serves as a significant
`improvement to the competitor's product.
`0039 FIG. 8 and FIG. 9 illustrate a perspective top and
`bottom view of the probe actuator of the lancing device
`respectively, according to one embodiment of the present
`invention. The probe actuator 15 is equipped with an inte
`grated damper 35 positioned in the middle part, such that the
`damper 35 can be coupled to both the priming gear 11 and the
`probe actuator 15 at the same time. The probe actuator 15 is
`further equipped with a cam follower36, which drags over the
`cam profile surface 29, accurately tracing the surface of the
`cam. A frame slot 37 is located in the middle of the probe
`actuator 15 and comprises of two different parts; an outer
`circular ring 38 for capping over the guide pin 21 of the
`bottom case 4 and a small protrusion 39 from the damper 35,
`located inside the circular ring 38 to be inserted to the frame
`slot 22 of the guide pin 21 of the bottom case 4.
`0040. The connection between the damper 35, the probe
`actuator 15, torsion spring 16 and guide pin 21 of the bottom
`case 4 is further illustrated in FIG. 10. The inner surface of the
`guide pin 21 interacts with the damper 35, whereas the outer
`surface of the guide pin 21 interfaces with the circular ring 38
`
`of the probe actuator 15, providing guidance for the probe 10.
`The torsion spring 16 is positioned to be resting on outer
`surface of the probe actuator 15. Hence, the kinetic energy of
`the propelling lancet of the present invention is not dissipated
`through impact but rather through a gear-damper system. The
`gear-damper configuration will minimize or even eliminate
`the noise produced during the lancing process and will
`enhance the user's compliance significantly.
`0041
`Lancing device 1 according to the preferred
`embodiment in the present invention is designed such that any
`horizontal or vertical translation movement is minimized and
`the only freedom of movement allowed is rotation of the
`probe 10. The clearance between the slotted guides 34 and the
`guide pin 21 is the one determine the extent of the rotation.
`The profile slides 32 and 33 sit on the V-shaped profile guides
`23 and 24, rotating with the same center of rotation as that of
`the lancet 7, while the probe 10 sliding forward and backward
`during lancing process. The V-shaped profile guides 23 and 24
`are meant to eliminate movement of the probe 10 in y-axis
`during sliding of the lancet 7. The design of the lancet device
`1, is intended to minimize or eliminate the pitching and vibra
`tion of the lancet 7 and its holder, during lancing. This means
`that the lancet 7 is always guided, without any sliding clear
`ance for freedom of motion in horizontal or vertical direction,
`during its entire lancing trajectory. The only allowed freedom
`of motion for the lancet 7 during sliding is rotation, while
`horizontal or vertical translation is minimized or eliminated.
`The coincidence of the rotation centre of the lancet 7 and the
`profile slides 32 and 33, will ensure minimum or no lateral
`and only limited rotational movement of the lancet 7 during
`lancing process, and hence minimizing wound trauma and
`prevent the collapse of the wound channel, which will sig
`nificantly reduce the pain experienced by the user during
`lancing.
`0042. Besides cam profile 29, the ratio of the damper 35
`and the stiffness of the torsion spring 16 are other factors that
`determine the velocity profile of the lancet 7 It is preferred if
`the torsion spring 16 is not too stiff, as it will require more
`efforts from the user to prime it. The use of less stiffspring is
`compensated by proportionally reducing the damping. The
`damping effect can be appropriately adjusted by using differ
`ent size of damper. Lastly, the cam profile 29 will determine
`how much of the potential energy from the torsion spring 16
`is converted to the kinetic energy of the lancet 7. In Summary,
`the combination of the effect of different cam profile 29,
`different stiffness of the torsion spring 16 and different ratio
`of the damper 35 can be optimized for achieving desired
`velocity profile of the lancet 7.
`0043. After the lancing process, the lancet is then retracted
`from the skin of the user and the probe 10 will slide backward
`as the cam follower 36 of the probe actuator 15 moves along
`the cam profile 29 embedded in the probe 10. A top perspec
`tive view of the final assembly of the lancet device according
`to one embodiment of the present invention is shown in FIG.
`12.
`
`1. A lancing device, comprising:
`a lancet:
`a housing comprising guides for minimizing pitching of
`the lancet during lancing;
`a probe with cam profile for controlling the speed of the
`lancet such that the lancet enters the skin quickly, decel
`erates at Standstill at maximum depth of penetration and
`retracts controllably:
`
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`US 2010/0145377 A1
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`Jun. 10, 2010
`
`a gear-damper system for minimizing noise produced dur-
`ing lancing process; and
`a priming System.
`2. The lancing device as claimed in claim 1, wherein said
`guides comprise of V-shaped guides and profile guides, said
`V-shaped guides and profile guides are used together with leaf
`springs for minimizing or eliminating probe movement in X
`and y-axis during lancing process.
`3. The lancing device as claimed in claim 1, wherein said
`probe with cam profile comprises of profile slides having its
`rotation centre coinciding with the lancet's rotation centre.
`
`4. The lancing device as claimed in claim 1, wherein said
`probe with cam profile comprises of slotted guides for limit
`ing rotational movement of the probe during lancing process.
`5. The lancing device as claimed in claim 1, wherein said
`priming system comprises of a torsion spring, a probe actua
`tor, a priming gear, a rack, a priming button, a compression
`spring and a fire button.
`6. The lancing device as claimed in claim 5, wherein said
`probe actuator comprises of an integrated damper and a cam
`follower.
`
`ck
`
`Page 15 of 15
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