United States Patent
`
`[19]
`
`[11] Patent Number:
`
`4,990,154
`
`Feb. 5, 1991
`{45] Date of Patent:
`,
`Brown et al.
`
`
`[54] LANCET ASSEMBLY
`
`[75]
`
`Inventors:
`
`Iviichael K. Brown; Mohammad
`Kheiri, both of Elkhart, Ind.; D.
`Glenn Purcell, Edwardsburg, Mich.;
`William Taylor, Goshen; Robert
`Whitson, Osceola, both of Ind.
`
`Assignee: Miles Inc., Elkhart, Ind.
`
`Appl. No.: 367,862
`
`Filed:
`
`Jun. 19, 1989
`
`Int. Cl.5 .............................................. A61B 17/32
`U.S. Cl. ..................................... 606/182; 606/167
`Field of Search ................ 606/181, 182, 183, 167
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`6/1983 Burns .......................... 606/182
`4,388,925
`4,462,405 7/1984 Ehrlich .......
`4,637,403
`1/1987 Garcia et al.
`4,677,979
`
`Primary Examiner—Robert A. Hafer
`Assistant Examiner--Lynda M. Cofsky
`Attorney, Agent, or Firm—Roger N. Coe
`
`ABSTRACI‘
`[57]
`A lancet assembly includes a reusable base unit that
`defines a handle for a lancet assembly and houses a
`biasing mechanism for driving a lancet into the finger of
`a user. The base unit includes a spring biased hammer
`thatonce cocked, can be released to drive a lancet. A
`lancet is included in a disposable end cap that may be
`releasible attached to one end of the base unit. The end
`cap includes integral resilience spring fingers that main-
`tain the lancet completely within the end cap before and
`after use, and functions to return the lancet after en-
`gagement of the lancet and hammer. The end cap can be
`rotated to orient the end cap relative to a user’s finger to
`control the depth of penetration of the lancet into the
`user’s finger.
`
`10 Claims, 1 Drawing Sheet
`
`ACTA EX. 1020-001
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`ACTA Ex. 1020-001
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`

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`U.S. Patent
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`Feb. 5, 1991
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`Sheet 1 of 1
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`“Z?
`. ..‘‘‘‘\wn.\\\\\\\\\\\\\\\'
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`AW‘ /,
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`ACTA EX. 1020-002
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`ACTA Ex. 1020-002
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`

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`1
`
`LANCET ASSEMBLY
`
`4,990,154
`
`BACKGROUND OF THE INVENTION
`A. Field of the Invention
`The device of the present invention generally relates
`to a new and improved lancet assembly for puncturing
`the skin of a user to obtain a blood sample; and, more
`particularly, to a new and improved lancet assembly
`including a disposable end cap containing a one piece
`lancet.
`B. Description of the Prior Art
`Sharp pointed lancets are employed to make a punc-
`ture or penetration of a patient’s skin in order to provide
`a small outflow of blood. Various tests may be em-
`ployed with only small amounts of blood so that blood
`flowing from a finger prick is normally sufficient for
`these tests. Tests on the blood sample often include
`contacting a paper strip or reagent pad on a strip carry-
`ing chemistry with blood from the wound or puncture.
`Lancet assemblies now available include a driving
`member that grips a lancet. Loading and removing a
`lancet from the driving member of the assembly re-
`quires extra care by the user to avoid being punctured.
`The lancet must be carefully gripped to avoid contact
`with the sharp end of the lancet. Present day concerns
`about communicable diseases transmitted through body
`fluids such as blood increases the risks of handling these
`lancets.
`Current devices require the user to remove a protec-
`tive cover from the sharp end of a lancet, and load the
`exposed lancet into a lancet assembly. After use of the
`assembly, the point of the lancet is exposed. Users of
`these devices, such as nurses, are repeatedly handling
`these used, exposed lancets and have a high risk of 35
`puncture by a used lancet and resultant exposure to
`contamination through the blood on the lancet.
`Some designs of lancets include a end cap with the
`sharp end of the lancet contained within the end cap
`after use, and the opposite end of the lancet sticking out 40
`of the end cap. Upon removal of the end cap after use,
`it is possible for the user to be stuck with an infected
`lancet simply by pressing on the exposed end of the
`lancet thereby moving the sharp end of the lancet out of
`the end cap. This risk is especially high for professional 45
`users such as nurses who place used lancets in their
`pockets. At the end of the day the nurses reach into
`their pockets and pull out used items including lancets.
`Upon reaching into his or her pocket, the nurse can
`press the back end of a lancet thereby exposing the
`contaminated sharp point.
`One example of a known lancet is illustrated in U.S.
`Pat. No. 3,030,959. The lancet of this patent includes a
`spindle designed for housing a replaceable magazine
`containing a stock of needles. A feeding device for
`feeding a needle to be used is also disclosed. After a
`needle is used, it is maintained in the lancet until another
`needle from the magazine is loaded. As the new needle
`is advanced, the needle preceding it is ejected from the
`lancet. The lancet assembly of U.S. Pat. No. 3,030,959
`ejects an unprotected, exposed and contaminated needle
`which increases the risk of puncture by the user of the
`lancet assembly.
`A disposable needle probe package is disclosed in
`U.S. Pat. No. 4,637,403. The needle package is friction-
`ally held in the medical testing system by snapping,
`threading or similar procedures, and it is releasable by
`pushing the probe package out of the medical monitor-
`
`2
`ing system. Once the probe package is released from the
`monitoring system, however, the needle is exposed and
`handling can result in puncturing the skin of the user
`thereby exposing the user to contaminated blood.
`A lancet assembly intended to be disposable with no
`part of the assembly reused is disclosed in U.S. Pat. No.
`4,375,815. Examples of other lancet assemblies intended
`to be totally disposable, as opposed to disposing only
`the lancet, are disclosed in U.S. Pat. Nos. 4,388,925;
`4,553,541; 4,449,529 and 4,535,769.
`A disposable lancet defined by a plunger is disclosed
`in U.S. Pat. Nos. 4,712,548 and 4,738,261. After this
`device has been used, the lancet is exposed with the risk
`that someone handling the used device could be punc-
`tured by the contaminated lancet.
`Lancet assemblies in which used, exposed lancets
`must be removed with the risk of puncture are disclosed
`in U.S. Pat. Nos. 4,416,279; 4,462,405; 4,442,836 and
`4,469,110.
`U.S. Pat. No. 4,545,376 discloses a one piece, plastic
`lancet consisting of a handle and a tip. Once a protec-
`tive yoke is removed, the lancet tip is completely ex-
`posed and can accidentally puncture a user.
`Lancet assemblies that are totally disposable with no
`reusable components are disclosed in U.S. Pat. Nos.
`4,624,253; 4,616,649 and 4,539,988.
`A lancet assembly with a lancet exposed after use is
`disclosed in U.S. Pat. No. 4,452,243.
`Some lancet assemblies provide for the depth of pene-
`tration of the lancet into the skin of a user or patient to
`be adjustable. Adjustability has been accomplished in
`some prior art lancet assemblies by using removable end
`caps. Typically, prior art lancet assemblies can be used
`with one of two end caps each having different size
`holes allowing different amounts of the skin of the fin-
`ger to be contacted. With a greater amount of skin
`fitting into the hole, the lancet can pierce deeper into
`the skin of the finger. With a lesser amount of skin
`fitting into the end cap through the hole, a shallower
`piercing will occur.
`There is a need for a lancet assembly in which the
`lancet is completely contained within a portion of the
`lancet assembly both before and after use such that the
`user can dispose of the lancet without risk of puncture.
`There also is a need for a lancet assembly that is easily
`and quickly adjustable to control the depth of penetra-
`tion of the lancet into the finger of a user or patient. In
`addition, there is a need for a lancet which is as painless
`as possible.
`
`SUMMARY OF THE INVENTION
`
`An object of the present invention is to provide a new
`and improved lancet assembly for piercing the skin of a
`user to extract blood for testing purposes.
`Another object of the present invention is to provide
`a new and improvement lancet assembly that can be
`easily adjusted to control the depth of penetration into
`the skin of the user.
`-
`A further object of the present invention is to provide
`a new and improved lancet assembly that includes a
`disposable, easily detachable end cap in which is totally
`contained a lancet that is not exposed before or after
`use.
`
`A still further object of the present invention is to
`provide a new and improved lancet assembly that in-
`cludes a molded, one piece lancet that can be fixedly
`
`ACTA EX. 1020-003
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`ACTA Ex. 1020-003
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`

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`3
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`4,990,154
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`secured in an end cap, separate from a driving member
`of the lancet assembly.
`A yet further object of the present invention is to
`provide a new and improved lancet assembly for pierc-
`ing the skin of a user as painlessly as possible in order to
`obtain blood for diagnostic test purposes.
`Briefly, the present invention is directed to a new and
`improved device commonly referred to as a lancet as-
`sembly used for puncturing the skin of a user or patient
`to allow blood from the puncture to be tested. The
`lancet assembly includes a base unit that defines a han-
`dle and houses a spring driven hammer. The hammer
`extends outward from one end of the base unit and is
`cocked by merely pushing the hammer into the base
`unit. This action compresses a spring and latches the
`hammer within the base unit.
`The lancet assembly also includes a disposable end
`cap that can be detachably secured to the base unit. The
`end cap includes an elongated slot through which a
`lancet extends when struck by the hammer. By rotating
`the end cap relative to the base unit, the slot is rotated
`relative to the finger of a user or a patient. In a first
`position of the end cap the lancet will penetrate deep
`into the skin of the user or patient. In a second position
`of the end cap the lancet will penetrate a shallower
`depth into the skin of the patient or user.
`The end cap includes integral resilient spring fingers
`formed on the inside of the end cap. A molded one piece
`lancet is positioned within the end cap against the spring
`fingers. When the end cap is attached to the base unit
`and the hammer released, the hammer strikes the lancet
`driving it through the slot in the end of the end cap. The
`resilient spring fingers then act to return the lancet to a
`position totally within the end cap.
`The lancet of the present invention includes a collar
`member with indexing structure. The indexing structure
`interfaces with complimentary structure on the inner
`peripheral surface of the end cap to lock the lancet
`relative to the end cap such that the lancet will move
`with the end cap when the end cap is rotated to orien-
`tate the elongated slot. The lancet also includes a pierc-
`ing end that is driven into the skin of the user or patient,
`and an anvil end that is struck by the hammer. After the
`lancet has been used, the end cap can be easily removed
`or snapped off of the base unit and no portion of the
`lancet is exposed outside of the end cap. In this condi-
`tion, the end cap can be carried or handled without risk
`of puncturing the hand of the user and exposing the user
`to contaminated blood.
`
`55
`
`BRIEF DESCRIPTION OF THE DRACWINGS
`
`The above and other objects and advantages and
`novel features of the present invention will become
`apparent upon reading the following detailed descrip-
`tion of a preferred embodiment of the invention illus-
`trated in the accompanying drawings wherein:
`FIG. I is an exploded, enlarged, perspective view of
`a lancet assembly constructed in accordance with the
`objectives of the present invention;
`FIG. 2 is a vertical cross sectional View of the end cap
`of the lancet assembly taken along line 2-2. in FIG. 11;
`FIG. 3 is a vertical cross sectional view of the end cap
`taken along line 3—3 in FIG. ll;
`FIG. 4 is an enlarged, partially cross sectioned view
`of a lancet used in the lancet assembly illustrated in
`FIG. 11;
`FIG. 5 is an enlarged View similar to FIG. 2 with a
`lancet mounted within the end cap; and
`
`4
`FIG. 6 is an end view of the end cap with a lancet
`mounted therein.
`_
`While the invention is susceptible to various modifi-
`cations and alternative forms, specific embodiments
`thereof have been shown by way of example in the
`drawings and will be described in detail herein.
`It
`should be understood, however, that it is not intended
`to limit the invention to the particular forms disclosed,
`but on the contrary, the intention is to cover all modifi-
`cations, equivalents, and alternatives falling within the
`spirit and scope of the invention as defined by the ap-
`pended claims.
`
`DESCRIPTION OF THE PREFERRED
`EMBODIMENT
`
`Referring initially to the drawings and specifically to
`FIG. ll; there is illustrated a lancet assembly generally
`designated by the reference numeral 110. The lancet
`assembly 110 prevents accidental puncturing of the skin
`of a professional user of the assembly 10 such as a nurse
`or other health care professional. The lancet assembly
`110 includes two separate components, a reusable base
`unit generally designated by the reference numeral I2,
`and disposable end cap generally designated by the
`reference numeral 14». The combination of a reusable
`base unit 312 with a disposable end cap 14 significantly
`reduces the cost of the lancet assembly 110 and increases
`the safety to the user.
`The end cap I4 is designed to house a lancet generally
`designated by the reference numeral 16. The base unit
`12 houses a hammer 118 that engages or strikes the lancet
`116 and drives the lancet 116 into the skin of a patient or
`user. The hammer 18 differs from the typical driving
`member in prior art lancet assemblies. The hammer 18
`functions as a striking element, striking the lancet 16 as
`opposed to gripping the lancet and carrying the lancet
`with the hammer. Instead of a gripping structure, the
`hammer 18 includes a flat striking face 26. By using a
`hammer 18 instead of a driving member that grips the
`lancet 16, the lancet 116 does not need to extend out of
`the end cap ‘I4 to be attached to the hammer 18. Rather,
`the lancet 116 is located totally within the end cap 114.
`This increases the safety of the lancet assembly 10 since
`once the lancet 16 has been used and it is contaminated
`with blood or other body fluids, the end cap M» can be
`disposed of without the danger of the contaminated
`lancet 116 contacting the finger of the user.
`The hammer 18 should be of considerably more mass
`than the lancet 16. Due to the greater mass, as the ham-
`mer I8 is accelerated towards the lancet 116 under the
`influence of a compressed spring 20 in the base unit 12,
`the transference of linear momentum from the impact of
`the hammer 18 gives the lancet 116 a high velocity in a
`direction outward of the end cap 14». The lancet 16 is
`then returned to a position completely within the end
`cap 114 by spring fingers 22, molded on the inside of the
`end cap 114.
`The base unit 112 is similar to prior art lancet assem-
`blies. By pushing the hammer I8 inwardly into the base
`unit 112, the spring 20 is compressed and stores energy.
`As the hammer 118 is moved into the base unit 12, the
`hammer 318 is latched in position and held within the
`base unit 312 until a button 24!» is pushed by a user. Push-
`ing the button 24 releases the hammer 18. The hammer
`11815 then driven outwardly of the base unit 12 under the
`biasing force of the spring 20.
`The disposable end cap 114 includes an open end 28
`which snaps over a hammer end 30 of the base unit 3122.
`
`ACTA EX. 1020-004
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`ACTA Ex. 1020-004
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`

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`4,990,154
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`10
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`55
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`65
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`20
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`5
`'
`A snap or friction fit is provided by an inner peripheral
`rim 32 on the end cap 14. The engagement of the rim 32
`with the outer peripheral surface of the base unit 12
`holds the end cap 14 onto the base unit 12 with the
`hammer 18 aligned to extend into the open end 28 of the
`disposable end cap 14. To allow easy removal of the end
`cap 14 for disposal, a flange 34 is formed on the outer
`periphery of the disposable end cap 14 adjacent
`the
`open end 28. After blood has been drawn, the user of
`the lancet assembly 10 may remove the disposable end
`cap 14 merely by pushing against the flange 34 to move
`the end cap 14 off the end 30 of the base unit 12.
`The disposable end cap 14 includes a closed end 36
`with an elongated slot 38 formed in the closed end 36.
`The slot 38 is of a length that is greater than its width.
`This slot 38 controls the depth of penetration of the
`lancet 16 into the skin of a patient. More specifically, by
`aligning the length of the slot 38 with the length of a
`patent’s finger, more of the patient’s skin is moved into
`the slot 38 allowing deeper penetration of the lancet 16
`into the patient’s finger. By rotating the end cap 14 such
`that the length of the slot 38 extends across the finger of
`the patient, less skin enters into the slot 38 and shal-
`lower penetration of the lancet 16 into the skin results.
`Consequently, the user of the lancet assembly 10 can
`control the depth of penetration of the lancet 16 into the
`skin of a patient by rotating the disposable end cap 14
`relative to the base unit 12.
`The user of the lancet assembly 10 can ascertain the
`orientation of the slot 38 by viewing the location of a
`pair of ribs 40 formed on opposite sides of the disposable
`end cap 14. The ribs 40 are aligned with the ends of the
`longitudinal slot 38. By determining the location of the
`ribs 40 relative to the finger of a patient, a user can
`determine whether the lancet assembly 10 is aligned for
`deep or shallow penetration.
`The end cap 14 is designed to contain the lancet 16
`entirely within it before and after use of a lancet assem-
`bly 10. The lancet 16 is maintained within the end cap
`14 before use and returned to a position within the end
`cap 14 after use by the resilient spring fingers 22 inte-
`grally molded on the inside of the end cap 14. Prefera-
`bly, the end cap 14 is molded of polyethylene which is
`a flexible material allowing the spring fingers 22 to be
`molded as a single piece with the end cap 14. Polyethyl-
`ene provides sufficient resilience to return the lancet 16
`to a position within the end cap after the lancet 16 has
`been struck by the hammer 18.
`The movement of the lancet 16 is guided by ribs 42
`molded on the interior of the end cap 14. The ribs 42
`also function to index a fluted collar 44 on the lancet 16.
`The fluted collar 44 includes arms or flutes 46 that
`function as indexing structures by engaging the ribs 42
`of the end cap 14. This engagement of the ribs 42 and
`arms 46 aligns the lancet 16 within the end cap 14. The
`lancet 16 includes an anvil end 48 that is engaged by the
`hammer 18 to drive the lancet 16 through the slot 38 of
`the end cap 14. As this occurs, the ribs 42 engage the
`arms 46 guiding the movement of the lancet 16 as driven
`by the hammer 18 and as returned to its original position 60
`by the spring fingers 22. In addition, the engagement of
`the indexing structure as defined by the ribs 42 and arms
`46 allows the lancet 16 to rotate with the end cap 14 as
`the end cap 14 is rotated relative to the base unit 12 to
`align the slot 38 with the length or width of a finger of
`a patient.
`In one embodiment of the present invention, a user
`purchases the base unit 12 and can use the base unit
`
`6
`many times before replacement is necessary. The dis-
`posable end caps 14 are purchased in quantity. The end
`caps 14 include the lancet 16 already assembled within
`the end cap 14. The lancet 16 is located within the end
`cap 14 with the arms 46 engaging the ribs 42. A flange
`50 on the fluted collar 44 is snapped behind snaps 52
`(FIG. 3) formed on the inner peripheral surface of the
`end cap 14. The snaps 52 hold the lancet 16 within the
`end cap 14 and prevent it from falling out the open end
`28 prior to attaching the end cap 14 to the base unit 12.
`The lancet 16 includes a needle or other sharp object
`54 that pierces the skin of a patient. Prior to actual use,
`the needle 54 is covered by a needle plug 56. The needle
`plug 56 is made of a soft material into which the needle
`54 extends. The needle plug 56 includes a flat griping
`surface 58 that extends through the slot 38 when the
`lancet 16 is mounted or assembled within the end cap
`14. To use the lancet assembly 10, a user snaps a dispos-
`able end cap 14 onto the base unit 12. The user then
`grips the gripping surface 58 of the needle plug 56, and
`with slight pulling pressure removes the needle plug 56
`from the needle 54. The spring fingers 22 then move the
`lancet 16 inside the end cap 14 such that the needle 54 is
`safely within the end cap 14. The lancet 16 is also held
`into position within the end cap 14 by the snaps 52 such
`that the anvil end 48 of the lancet 16 does not extend
`through the open end 28 of the end cap 14. Thus, while
`the end cap 14 is attached to the base unit 12, no portion
`of the lancet 16 is exposed outside the end cap 14.
`Once the end cap 14 has been snapped onto the base
`unit 12 and the needle plug 56 removed from the needle
`54, the user may push the button 24 to release the ham-
`mer 18 under the influence of the spring 20. The ham-
`mer 18 strikes the anvil end 48 of the lancet 16 driving
`the lancet 16 against the spring fingers 22. The needle 54
`moves through the slot 38 and into the skin of a patient.
`Once the momentum of the hammer 18 has been ex-
`hausted, the spring fingers 22 quickly return the needle
`54 to the position illustrated in FIG. 5. In this position,
`the needle 54 is completely within the end cap 14. After
`a sample of blood has been drawn, the user may snap off
`the disposable end cap 14 merely by engaging the flange
`34 with a thumb and popping or snapping the end cap
`14 off the base unit 12. The spring fingers 22 and the
`snaps 52 hold the lancet 16 entirely within the end cap
`14. Since the hammer 18 strikes the lancet 16 rather than
`gripping it, the anvil end 48 of the lancet 16 does not
`extend outside of the end cap 14. The contaminated
`disposable end cap 14 can then be handled by the user
`without the danger of engaging the contaminated nee-
`dle 54, or hitting the anvil end 48 and pushing the needle
`54 outside the end cap 14 where it can puncture the skin
`of the person handling the end cap 14.
`Another advantage of the spring fingers 22 is that
`they cause the needle 54 to be quickly retracted from
`the skin of a patient and this results in less pain for the
`patient.
`The lancet assembly 10 of the present invention pro-
`vides increased safety for the user by totally containing
`the contaminated lancet 16 within the end cap 14. After
`the lancet 16 has been used and the end cap 14 removed
`from the base unit 14, there is no portion of the lancet 16
`outside the end cap 14 that can be engaged by the user
`during handling. Consequently, the contaminated nee-
`dle 54 cannot be contacted by the user and disposal of
`the end cap 14 can be accomplished safely.
`What is claimed and sought in United States Letters
`Patent is:
`
`ACTA EX. 1020-005
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`ACTA Ex. 1020-005
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`

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`4,990,154
`
`'7
`11. A lancet assembly comprising:
`a base unit providing a handle for said lancet assem-=
`bly,
`a disposable end cap releasably attachable to said base
`unit,
`a lancet mounted in and entirely contained within
`said end cap,
`a hammer member mounted in said base unit for en-
`gaging and driving said lancet in said end cap, and
`a lancet return member located within said end cap
`for moving the entire lancet totally within said end
`cap after said lancet is driven by said hammer.
`2.. The lancet assembly set forth in claim 11, wherein
`said base unit includes a first biasing member mounted
`in said base unit for engaging and driving said hammer
`into said lancet.
`3. The lancet assembly set forth in claim 1 wherein
`said end cap includes a closed end with an elongated
`slot through which said lancet extends upon engage-
`ment of said hammer member with said lancet, said end
`cap being rotatable mounted on said base unit to orient
`said elongated slot and control the engagement of said
`lancet with a finger of a user of said lancet assembly.
`4. The lancet assembly set forth in claim 11 wherein
`said lancet return member comprises a second biasing
`member for biasing said lancet inside said end cap such
`that said lancet is completely contained in said end cap
`prior to, during and after attachment to said base unit.
`5. The lancet assembly set forth in claim it further
`comprising a flange on the exterior of said end cap for
`engagement by a user of said lancet assembly to remove
`said end cap from said base unit.
`6. The lancet assembly set forth in claim it wherein
`said lancet includes a collar, and indexing structure on
`
`83
`said collar and a corresponding structure in said end cap
`wherein the interaction of said indexing structure and
`said corresponding structure allows said lancet to move
`with said end cap upon rotation of said end cap relative
`to said base unit.
`7. The lancet assembly set forth in claim it wherein
`said base unit and said end cap are fabricated of polyeth-=
`ylene.
`8. An assembly for piercing skin to obtain a blood
`specimen, comprising:
`a reusable base member housing a driving member.
`said driving member being a hammer,
`a disposable end cap, said end cap including a ‘first
`end adapted for releasable attachment to said base
`member,
`a lancet mounted in said end cap for engagement by
`said driving member after attachment of said end
`_g cap to said base member, and
`a resilient element in said end cap for biasing said
`lancet completely within said end cap when said
`lancet is not engaged by said driving member.
`9. The assembly claimed in claim 8 wherein said end
`cap includes a second end, a diagonal slot in said second
`end, wherein the orientation of said slot on the skin of a
`user defines the depth of penetration of said lancet into
`the skin of a user.
`10. The assembly claimed in claim 8 wherein said
`lancet includes a skin piercing end, an anvil end for
`engagement by said hammer, and an orienting member
`for mating with the inside of said end cap to orient said
`lancet in said end cap and to prevent rotation of said
`lancet relative to said end cap.
`3
`$
`£1
`1)
`3
`
`ACTA EX. 1020-006
`
`ACTA Ex. 1020-006