LANCET APPARATUS AND METHODS

FIELD OF THE INVENTION

This invention relates generally to lancets and more particularly to novel, self-

contained, precocked and single-use lancets which, when activated, extend a tip of a

lancet blade outward from a lancet housing and back into the housing for safe

disposal. In a preferred embodiment, the housing is sealed to maintain sterility of the

blade before use. A portion of the housing is preferably frangible, and the portion is

franged to initiate a single lancing cycle and to subsequently make the lancet

unreusable.

BACKGROUND OF THE INVENTION

In particular, U.S. Patent Number 5,514,152 (Smith), issued May 7, 1996,

discloses a lancet having a cocked torsion spring wound about a centrally disposed

hub frangibly connected to a lancet housing. Generally, the housing is disclosed to be

a container for a plurality of lancets, each of which, after use, is frangibly separated

from the rest of the strip and individually discarded. The spring is directly

interconnected to a lancet blade in a cam/cam follower relationship. When the hub is

frangibly separated from the housing, the cocked spring is released to drive a lancet

blade tip linearly from the housing and then return it safely back into the housing.

Smith discloses frangible separation of the hub from the housing where a base

of the hub is annularly connected by sharp corners to the housing. It is taught that

stress placed upon the base causes the hub to frange from the housing, permitting the

lancing cycle to begin. Of course, before each lancing cycle is initiated, a housing

exit is exposed to provide an orifice through which the lancet blade tip travels. It is

only when the orifice is provided that the sterility of the package is compromised,

thereby making the blade and internal contents sterile until that time.

SUMMARY OF THE INVENTION

In brief summary, this novel invention alleviates all known major problems

related to providing a molded housing for both a lancet strip and single lancet device

and further combines a lancet carrier with a lancet housing into a unitary single lancet

device. One and two activation step embodiments of the single lancet devices are

disclosed, the one step embodiments being presently preferred. Generally, the one

step embodiments comprise a single action (step) by a user; however, two functions

(breaking of a sterile barrier and initiation of a lancet cycle) are combined in the single

step. Commonly, the two step embodiments require a first step to break a sterile

barrier and a second step to initiate a lancet cycle. While there are few other

advantages or disadvantages to one or two step operation, the first step of the two step

embodiment is often regarded as causing lost or wasted time by a user.

Similar to Smith (cited above), the invention comprises a rapid outwardly

driven and then inwardly retracted lancet blade in a cycle, which is initiated by

franging a hub, disposed within and securely affixed to a cocked spring, from an

integrally associated housing. This invention, however, embodies a novel molded

interconnection between the hub and housing to assure that the hub will be easily

franged from the housing and will rotate freely within the spring. Moreover, the

molded interconnection does not comprise extraneous fragments about the edges at

frange sites, which can catch upon other edges of the housing and inadvertently keep

the spring from unwinding and preventing the blade from completing a lancing cycle.

Accordingly, it is a primary object of the present invention to provide a one¬

time-use, self-driven lancet having a readily frangible, molded connection between a

hub and housing which permits the hub to separate from the housing without

extraneous fragments being disposed about the hub where the hub/housing frange is

disposed.

It is another primary object of the present invention to provide a single, one¬

time-use lancet embodiment in which a carrier and lancet housing are combined in a

single disposable unit.

It is an important object of the present invention to provide an embodiment of

the single, one-time-use lancet which operates in two steps, one of which is to break a

sterile barrier and the other of which is to initiate a lancet cycle.

It is a further object of the present invention to provide an embodiment of the

single, one time use lancet which operates in a single step, wherein the breaking of a

sterile barrier and initiating of a lancet cycle are performed in a single operating step.

It is another object of the present invention to provide an embodiment of the

single, one-time-use lancet which operates in the single step of squeezing two

displaced, but juxtaposed parts together to perform the two steps of breaking the

sterile barrier and initiating the lancet cycle.

It is yet another object of the present invention to provide a lancet blade which

is facilely used in automated assembly of a lancet.

It is an additional object of the present invention to provide a strip of

presterilized lancets from which a used lancet is frangibly separated without

disturbing the sterile condition of any other lancet in the strip.

It is a further object of the present invention to provide a lancet housing

having a molded hub which is freely, frangibly separated from the rest of the housing.

These and other objects and features of the present invention will be apparent

from the detailed description taken with reference to accompanying drawings which

follow, or may be learned by the practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a planar view showing the inner surface of a related art

representation of a lancet housing assembly member.

Figure 2 is an exploded perspective view of a related art lancet housing

assembly compartment of the lancet housing assembly member shown in Figure 1,

comprising a lancet blade and torsion spring in cocked orientation.

Figure 3 is a planar view of the inner surface of a related art representation of a

cover for the lancet housing assembly member shown in Figure 1.

Figure 4 is a planar view of the inner surface of the lancet housing assembly

member seen in Figure 1 with the torsion spring and lancet blade in place and

adhesive distributed on the higher surfaces.

Figure 5 is a top elevation of an assembled lancet housing assembly

compartment seen in Figure 1 without a cover.

Figure 6 is a top elevation of a lancet compartment depicted in Figure 5,

showing a fired lancet in mid-cycle wherein a tip of a lancet blade, which is a key part

of a lancet assembly, is protruding from the lancet compartment.

Figure 7 is similar to Figure 5, but showing a spent lancet with the lancet tip

retracted into the lancet compartment.

Figure 8 is a section taken along lines 8-8 in Figure 4; shown without a lancet

for clarity of presentation.

Figure 9 is a perspective drawing showing a related art representation of the

direction of insertion of a lancet housing into a housing carrier.

Figure 10 is a perspective drawing showing the initial position of the lancet

housing shown in Figure 9 and properly inserted into the housing carrier.

Figure 11 is a perspective drawing of the housing and carrier illustrated in

Figure 10, showing the distal end of a lancet compartment newly exposed by frangible

separation from a preceding compartment and revealing an exit aperture for a first to-

be-used lancet.

Figure 12 is a perspective drawing of the housing and carrier illustrated in

Figure 11 , showing a used lancet compartment frangibly separated from the remainder

of the housing and revealing an exit aperture for a next to-be-used lancet.

Figure 13 is a top elevation view of a lancet blade of the present invention.

Figure 14 is a perspective of a plurality of blades affixed to a blade magazine

for automatically loading blades into the lancet housings.

Figure 15 is a perspective of a strip of lancets comprising a blank section

disposed between each lancet.

Figure 16 is a perspective of the strip of lancets shown in Figure 16 with a

blank section frangibly separated from the rest of the strip to expose a shroud about an

exit and reentry slot for a lancet blade.

Figure 17 is an inverted section along lines 17-17 of Figure 15.

Figure 18 is a segment of a section along lines 18-18 of Figure 15.

Figure 19 is a perspective of an unused single lancet comprising a lancet

actuating arm prominently disposed on the outside of an outer lancet housing.

Figure 20 is a perspective of the lancet shown in Figure 19 after a completed

lancing cycle.

Figure 21 is a perspective of another unused single lancet housed in a self-

contained transport package.

Figure 22 is a perspective of the single lancet of Figure 22, after the lancet has

been used.

Figure 23 is a cross section along lines 23-23 of Figure 21, with some parts

removed for clarity of presentation.

Figure 24 is a perspective of an unused lancet disposed for protection in a

bubble pack to retain lancet sterility.

Figure 25 is a perspective of the unused lancet shown in Figure 19 and

removed from the bubble pack for use.

Figure 26 is a perspective of the lancet of Figure 25 after use.

Figure 27 is a top elevation of another single unused lancet with parts removed

for clarity of presentation.

Figure 28 is a top elevation of the lancet shown in Figure 27 after use.

DETAILED DESCRIPTION OF THE INVENTION

In this description, the term proximal is used to indicate the segment of a

device or other apparatus normally closer to a user when the device is properly used.

The term distal refers to a direction which is farther removed from the user than a

segment which is proximal. Reference is now made to the embodiments illustrated in

Figures 1-28 wherein like numerals are used to designate like parts throughout. In

order to properly reference novelty of the instant invention, a summary of a portion of

the disclosure found in Smith is provided and referenced as related art.

Reference is made to Figure 1 which shows the inner surface of a lancet

assembly member 10 of the preferred embodiment of Smith. Assembly member 10

comprises distal end 20, proximal end 30, and multiple empty housing compartments

40 separated by frangible segments 42 whereat the housing compartments can be

easily and manually separated without special tools. Assembly alignment pin holes

44 and 46 are also shown. Construction of each housing compartment 40, which is an

integral operating portion of each individual lancet 41, is substantially the same as

each of the others. As can be more easily seen in Figure 2, typically each housing

compartment 40 comprises a hub 50, a torsion spring anchor slot 62 which is an

integral part of hub 50, a lancet blade slide plane 70, guides 80 and 81, and at least

one frangible section 90, associated with frangible segment 42. Hub 50, placed

substantially in the center of compartment 40, is part of the lancet triggering

mechanism disclosed in detail hereafter. Groove 60 across the centerline of hub 50

provides a locking apparatus for that part of a torsion spring which will drive the

lancet when the spring is freed to unwind. The torsion spring anchor slot 62 holds a

lower end of the torsion spring immobile in compartment 40. Lancet slide plane 70 is

inset below an inner surface 92 to provide parallel lancet edge guides 80 and 81 which

provide a controlled line of travel on each side of a lancet blade. The lancet slide

plane 70, edge guides 80 and 81, and a travel limit edge 94 (described in detail

hereafter), each being an integral part of the lancet structure and function, are included

in the encapsulating housing structure in this embodiment.

A channel 96 which is an extension of slide plane 70 extends across a

frangible area 42 such that, when a top cover completes the housing and separation

occurs at frangible section 90, an egress/ingress port or aperture 98 is opened. The

line of separation is determined by a "V" groove having an apex at section 90 and

formed by compartment end apparatus comprising vertical end 102 and slanted end

104. The function of the frangible section and end apparatus is discussed in more

detail hereafter.

Other than a spring release associated with hub 50, the moving parts of a total

lancet assembly 100 (best seen in Figure 2) comprise torsion spring 110 and lancet

blade 120. A preferred embodiment of torsion spring 110 in Smith is shown in Figure

2. Spring 110 comprises spring wire wound into a torsion spring having a lower end

122 which extends horizontally outward from a central core 123 of spring 110. On

the other end, spring 110 is bent centrally such that it forms a straight horizontal

segment 124 which can be locked into groove 60 when the wound torsion spring 110

is press-fit over hub 50. To assemble a lancet according to Smith, a tightly wound

torsion spring 110 is pressed over hub 50 such that the lower spring end 122 is firmly

affixed into anchor slot 62 and the horizontal straight spring section 124 is firmly

pressed into groove 60. At the wire end of straight segment 124 the spring is bent

vertically upward forming crank arm 126, which is used to form an interlock between

torsion spring 110 and a coupling slot 130 of lancet blade 120. Thus, crank arm 126

comprises a cam and arcuate coupling slot 130 comprises a cam follower. The

cam/cam follower structure, sometimes referred to as a track structure, provides rotary

to linear motion translation.

In Smith, lancet assembly 100 comprises lancet blade 120 which is of unitary,

stainless steel construction comprising a very sharp lancet tip 140, torsion spring 110,

coupling slot 130, guide edges 132 and 133, and leading edge 134. To complete

assembly of lancet bottom housing 10 in a compartment 40, lancet blade slot 130 is

placed over the already positioned torsion spring crank arm 126 such that lancet blade

120 lies on slide plane 70 with lancet tip 140 in channel 96 and edges 132 and 133 in

line with edge guides 80 and 81.

A top elevation view of lancet bottom housing 10, having a plurality of lancet

blades 120 and springs 110 assembled therein, is shown in Figure 4. A housing cover,

which normally covers the lancet bottom housing 10, is not shown for clarity of

presentation but is described in detail hereafter. Torsion spring 110 is cocked and

held firmly in place by a slot 62 and a groove 60. Before lancet blade 120 can be

fired, the lancet tip 140 exit aperture 98 is opened by frangibly separating the lancet

bottom housing 10 within a frangible area 42.

The lancet is actuated by breaking the attachment of the hub 50 free from the

compartment 40. One mode of actuation is best seen in Figure 8, which is a section

along lines 8-8 of Figure 4, with lancet blade 120 removed for clarity of presentation.

Hub 50 is connected to compartment 40 by a frangible diaphragm 142 comprising

rounding annular corners 144 and sharp corners 146. Frangible diaphragm 142

comprises an annular actuator area 147 which first holds hub 50 from movement and,

upon frangible actuation, releases hub 50 to rotate as forced by the released biasing

memory of torsion spring 110. A recess 148 in diaphragm 142 causes actuator

diaphragm 142 to be attached to hub 50 with a reduced cross section at sharp corners

146 forming actuator area 147. To actuate the lancet, an external force is applied to

the recessed portion 148 of diaphragm 142, causing actuator diaphragm 142 and hub

50 to be deflected slightly. Note that the recess 148 makes inadvertent deflection

more unlikely. A deflection causes stresses to be generated at sharp corners 146 and

results in the fracture of hub 50 from actuator diaphragm 142 in the region of sharp

corners 146. When viewed from inner surface 92, (see Figure 2) the freed hub 50 is

released to spin in a counter clockwise direction as the biasing memory of the cocked

torsion spring 110 is freed to unwind.

As can best be seen in sequence in Figures 5, 6, and 7, crank arm 126 moves in

an approximately circular motion as hub 50 and spring 110 rotate, and crank arm 126

slides laterally in slot 130 as it drives the lancet tip 140 linearly outward through the

egress/ingress port 98 from the face of frangibly separated section 90. As shown in

Figure 6, lancet blade 120, guided by edges 80 and 81 and forced by crank arm 126,

moves lancet tip 140 outward until crank arm 126 begins drawing blade 120

proximally back into cavity 40, which retards the leading edge 134 of the lancet blade

120 from colliding with travel limit edge 94. Leading edge 94 provides a safety limit

for lancet blade tip 140 travel. In this manner, the depth of lancet tip 140 penetration

is precisely determined. The depth of puncture in the currently preferred embodiment

is 1.7 to 3.0 millimeters.

Further unwinding of torsion spring 110 continues to drive crank arm 126 in a

nearly circular counter clockwise direction causing lancet blade 120 to be retracted as

shown in Figure 7, thereby completing translation of torsion spring 110 rotary motion

to bi-directional linear travel of lancet blade 120. With a cover in place, lancet

compartment 40, now containing a totally retracted spent lancet 120, is a safe

disposable. There is no "bounce" or multiple excursion of lancet tip 140 from the

housing because the forcing direction of the biasing memory of the torsion spring

forces lancet blade 120 away from travel limit edge 94 and egress/ingress port 98.

An enveloping or encapsulating housing cover 150 is shown in Figure 3.

Cover 150 is inverted, disposed to cover a bottom 10 after assembly, and permanently

affixed thereto by either adhesion, ultrasonic bonding or another plastic adhesion

method, such as thermal bonding. Once a spring 110 and a blade 120 are mounted

into each lancet compartment 40, cover part 150 is accurately positioned relative to

bottom 10 through the use of alignment pins and holes or by ridges and grooves used

in ultrasonic bonding to cover every compartment 40. It is important that the strip

formed by joining bottom 10 and cover 150 form a hermetically sealed unit which

does not require further packaging for transport prior to use.

Smith discloses that both bottom 10 and cover 150 members may be molded

from synthetic resinous material such as, but not limited to, polymethylmethacrylate,

filled polypropylene, polystyrene, and acrylics. Depending upon the material used,

bonding may be accomplished by using methods comprising adhesives, and thermal

and ultrasound heating processes.

Either prior to or after encapsulation, all internal parts of the packets

comprising a fully assembled lancet housing 200 (see Figure 9) with precocked

lancets can be sterilized by radiation or like methods which are well known in the art,

thereby making internally disposed finger piercing elements aseptic. Each lancet

compartment is separately and hermetically sealed from all others such that

contamination of the parts of one compartment does not contaminate parts of any

other. Each encapsulated compartment 40 is its own hermetically sealed container

and retains an aseptic condition until egress/ingress port 98 is opened.

Reference is now made to Figures 9-12 wherein a lancet strip 200 and carrier

400 are seen. In use, carrier 400 holds lancet strip 200 which comprises a joined

bottom 10 and cover 150, for easier handling as strip 200 is serially shortened when

each spent lancet housed in a compartment 40 is frangibly separated and discarded

(see Figures 10-12). Carrier 400 also provides a special tool for triggering each

lancet. Except for blank sections on proximal and distal ends 152 and 154,

respectively, each individual lancet 41 is juxtaposed with and joined to an adjacent

individual lancet 41, such that separating and discarding a lancet in a previously used

individual lancet 41 generally results in exposing a lance blade exit orifice associated

with a channel 96. If the newly exposed orifice is not used immediately, there is a

significant likelihood that a portion of the lancet travel channel 96 will become

contaminated before ultimate use. As Smith teaches a slot which forms channel 96,

there is a greater likelihood that blood emitted from a lance site may contaminate an

area surrounding the carrier 400 or carrier 400 itself. It is one of the main objects of

this instant invention to prevent that event.

In the following detailed description of the instant invention, items which are

similar in form and function to those of the related art described in Smith are

commonly denoted by the same reference number primed. As an example, an

individual lancet which is similar in form and function, but not entirely identical, to

individual lancet 41 is denoted by 41' (see Figure 15).

Attention is drawn to Figure 13 wherein a lancet blade 500 of the instant

invention is seen. Blade 500 comprises a slot 130', which is similar in form and

function to slot 130, and a sharpened lancing tip 140'. However, blade 500 differs

markedly from blade 120 by proximally disposed protrusions 502 and 504 on blade

500. As best seen in Figure 13, blade 500 comprises an edge 506, transversely

disposed to the direction of the travel of lancet tip 140' and proximally disposed

relative to slot 130'. On one side, edge 506 curves arcuately away from slot 130' at a

rounded corner 508 to travel normal to the general direction of slot 130' and then

curves inward and then outward to form a bulbus inwardly protruding section 510.

Edge 506 then continues outward and forward (distal) to complete an outline of blade

500. On the other side, edge 506 curves similarly, but as a mirror image, arcuately

away from slot 130' at a rounded corner 512 to also travel normal to the general

direction of slot 130' and then curves inward and then outward to form a second

bulbus inwardly protruding section 514. From this point, edge 506 continues to

define the entire circumference of blade 500.

The useful function of bulbus sections 510 and 514 is best seen in Figure 14.

As shown in Figure 14, an I-beam section 515 having front and back plates 516 and

518 and separated by a pair of channels 520 and 522, which are proportioned to accept

insertion of bulbus section 510 and 514, respectively, when vertically disposed

provides nesting support for a plurality of blades 500. At the bottom of I-beam

section 515, a feeder system which is of a form for feeding small, flat pieces is

disposed to act as an automatic gravity feeder for an automatic assembly machine (not

shown). Such feeders and automatic assembly machines are well known in the

automated assembly equipment art. By trapping and nesting a plurality of blades in

such an I-beam 515, blades are captured at a manufacturing site and transported and

then individually fed for assembly into an individual lancet during an automatic

assembly process. The presently preferred mode of manufacture of blades 500 is

through a process of coining. A two step coining process produces a blade having

virtually no rough edges and a sufficiently sharpened blade for lancing.

Attention is now directed to Figure 15 , wherein a strip 600 of individual

lancets 41' generally interposed between blank parts 602 and 604 is shown. Strip 600

is comprised of a bottom part 10' and a cover part 150'. Parts 10' and 150' are similar

in form and function to parts 10 and 150, but have marked and novel differences as

disclosed hereafter. Each individual lancet 41' is frangibly separated from associated

blank parts 602 and 604. It is preferred that blank part 604 be physically recognizable

and separable from the other parts of strip 600 for ease of determining the direction of

entry into a carrier. (See, for example, Figure 9.) Frange segments are denoted by

segments alternately numbered 606 and 608 in Figures 15 and 16. Generally,

franging at segment 606 separates a blank part 604 or 602 from an individual lancet

41' to expose a surface 610 of the individual lancet 41' for a lancing operation (as seen

in Figure 16).

It is important to note that the exposed surface 610 resulting from separating a

blank part (in Figure 16 the blank part is blank part 604), further exposes a shroud 612

about a slot (not seen, but similar to the slot which forms channel 96, shown in

Figures 5-7 and 11 and 12). Shroud 612 is formed by an arcuate raised section 614 in

an inverted bottom 10' in combination with a planar raised section 616 in an attached

cover 150'. Note that the slopes on exposed face 620, formed in combination by parts

of bottom 10' and cover 150', effectively extend shroud distally outward from the rest

of strip 600 to aseptically isolate the skin contacting areas of shroud 612. In this

manner, blood and other material emitted from a lance site is either contained or

effectively isolated from the distal portions of a carrier or other portions of strip 600

to be used later. Note also that shroud 612 comprises a sterile interior face 622 when

separated from a blank part 604 or 602. Thus, each subsequent individual lancet 41'

presents a sterile, confined interface to its associated lance site.

Reference is now made to Figure 17, wherein a bottom section 630 of an

individual lancet 41' is seen. Section 630 comprises a hub 50', which is substantially

the same as hub 50 earlier described, and which comprises a groove 60 (substantially

the same in form and function to groove 60 earlier disclosed). Further, bottom section

630 comprises an actuator diaphragm 142', which, as is the case of actuator diaphragm

142, is frangibly broken under pressure normal to a surface 632, which is a portion of

diaphragm 142'.

However, there is a major and critical difference between the structures of

diaphragm 142 and hub 50 and of diaphragm 142' and hub 50'. Careful and detailed

analysis of the frange lines associated with the parts molded in a form as disclosed for

diaphragm 142 and hub 50 revealed that franging hub 50 from diaphragm 142 would

often result in the creation of large fragments jutting outward from hub 50 and

catching and impeding rotation of the hub and spring. This would cause the lancet

blade to misfire or to not completely exit and return to compartment 40. Continued

analysis showed an apparent characteristic flow path in molded parts which caused a

somewhat surprising direction of development of a flow path and, therefore, a frange

line. That path resulted in an annular frange path which was directed outward from a

pressure placed upon a surface, such as surface 632. For this reason, an optimum

frangible connection between a hub and an actuator diaphragm was determined to be

through two annular grooves disposed about the base of the hub.

Relative dispositions of such grooves (annular grooves 634 and 636) are

shown in Figure 17. Two frange lines 638 and 640 are shown as examples of the

effective area of franging where hub 50' separates from diaphragm 142'. Of course,

these are only examples, but it is important that grooves 634 and 636 be so positioned

and of a depth that they intersect such an annular frange as hub 50' separates from

diaphragm 142'. It is also important that grooves 634 and 636 be separated by

sufficient material to permit physical stability until pressure is applied to surface 632.

By experimentation, it has been shown that optimal pressure is in the range of 10 to

30 pounds, and the thinnest material disposed between grooves 634 and 636 should be

in the range of 0.010 inches (0.025 centimeters). Currently, the preferred material for

bottom 630 and an associated cover is polystyrene, thirty percent filled with a mineral

filler, such as wollastonite. In a currently preferred embodiment, bottom 630 is

ultrasonically bonded to a cover. For this purpose, pointed protrusions 642 are

molded into the upper segment of bottom 630. Otherwise, lancet cavity 40' is similar

in form and function to cavity 40 previously described.

Figure 18 shows a longitudinal section of a portion of a bottom 630

comprising a first disposed blank 604 and a first-to-be-used individual lancet 41'.

Dashed line 644 denotes a frange line between blank 604 and individual lancet 41'.

Franging along line 644 opens shroud 612, thereby providing an exit and reentry

portal for lancet blade 500, not seen in Figure 18 for clarity of presentation. In Figure

18, the disposition of annular groove 634 relative to annular groove 636 is also seen.

A next frange line 646, along which individual lancet 41' is broken away from the rest

of other unused lancets, is proximally disposed relative to dashed line 644.

Reference is now made to Figures 19 and 20, wherein a single lancet 700 (as

opposed to a strip of lancets), is shown. Lancet 700 comprises an outer housing 702

and an inner housing 704. Outer housing 702 is a permanent part of lancet 700 and

comprises a shroud portal 706 and an actuator button and lever 708. Further, the outer

housing comprises a box-like shape having a superior surface 710, an inferior surface

712, a portal side 714, a closed side 716 and a back side 718. Disposed for slidable

insertion of inner housing 704 into outer housing 702, outer housing 702 comprises a

fourth side 720 having an opening for slidable movement of inner housing 704.

Inner housing 704 comprises a cavity (not shown) which is referenced

hereafter as cavity 41' due to its closeness in form and function with cavity 41'

previously disclosed. However, rather than a direct and integral connection with a

shroud, inner housing 704 comprises a substantially flat exit and entry portal 722

through which a lancet blade tip 140' passes during a lancing cycle. Though not

necessary, it is presently preferable that portal 722 have a slightly raised surface 724

by which inner housing 704 is frangibly affixed to a juxtaposed surface of outer

housing 702 before use.

An unused lancet 700 is seen in Figure 19. To prepare lancet 700 for use,

inner housing 704 is translated laterally in the direction of arrow 725, perhaps by

squeezing between a thumb and forefinger, until blade exit and reentry portal 722 is

centrally disposed within shroud portal 706. Such a position is easily achieved as side

718 of outer housing 702 acts as a stop, thereby limiting travel of housing 704. In the

process of providing the force for laterally translating housing 704 relative to housing

702, any portion of housing 704 which is affixed to housing 702 is frangibly

separated. Thus, prior to exerting the lateral translation force, the parts involved in

frangibly affixing housing 702 to housing 704 are best used to serve as a sterile barrier

about portal 722.

Once lancet 700 is prepared for use, shroud 706 is disposed about a site to be

lanced and actuator button and lever 708 is depressed to frangibly separate a hub 50'

from an actuator diaphragm 142', as disclosed earlier. Separation of hub 50' releases a

spring 110 and thereby drives blade 500 and its associated blade tip 140' through a

lancing cycle, while leaving blade tip 140' safely confined in cavity 40' at the end of

the cycle. It is evident that the step of preparation followed by a spring and blade

actuation step inherently makes lancet 700 a two-step device.

Reference is now made to Figures 21-28 wherein the parts and perspectives of

one-step devices are seen. One step devices are defined as lancets which are prepared

for actuation and actuated in a single user movement. In Figures 21 and 22, a lancet

750 in an unused state (Figure 21) and in a spent state (Figure 22) is seen. Note that

lancet 750 is similar in form to lancet 700. Lancet 750 comprises an outer housing

752 and an inner housing 754. The major difference, apparent from exterior views of

lancets 700 and 750, is the lack of an actuator button and lever 708 on lancet 750.

Actuation of lancet 700 is caused by an internally disposed franging system

which fires lancet 750 as inner housing 754 is transposed into outer housing 752. The

mode of actuation of lancet 750 is clearly seen in Figure 23. As seen in Figure 23,

inner housing 754 comprises a cavity 40', a spring 110, a blade 500, an actuator

diaphragm 142" and a hub 50". The diaphragm 142" and hub 50" combination seen in

Figure 23 primarily differs from the diaphragm and hub combinations disclosed

previously by an outwardly protruding conical hump 756 having a common axis with

hub 50". Note that, in line with hump 756, the outer housing 752 comprises an open

channel 758. Channel 758 is closed by an inwardly sloping surface 760. Sloping

surface 760 is positioned to interact with hump 756 as inner housing 754 is translated

into outer housing 752 at the time when portal 722 is approximately medially

disposed within shroud portal 706. Inward movement of inner housing 754 ultimately

causes surface 760 to collide with hump 756, thereby placing an increasing pressure

upon diaphragm 142" until hub 50' is frangibly separated from the diaphragm 142".

Note that the slope of surface 760 determines the mechanical advantage and,

therefore, the rate of change of force which must be imposed upon inner housing 754

relative to outer housing 752 to actuate a lancing cycle. The currently preferred

material for lancets 700 and 750 are the same as the material specified for parts of

strip 600.

Note that the force to actuate lancet 750 is transverse to the direction of travel

of lancet tip 140'. Another embodiment of a one-step lancet, i.e., one-step lancet 800,

is seen in Figures 24-26. There are two major differences between lancet 800 and

lancet 750. The first difference is that lancet 750, like lancet 700, preferably

comprises a frangible self-contained sterile seal disposed between a blade exit and

reentry port (e.g. port 722) and an internal surface of a side of an outer housing (e.g.

side 714). In this manner, no additional packaging is required to prevent

contamination of a lancet blade before use. The second difference is the direction of

actuation. As earlier stated, the actuation of lancet 750 is in a direction transverse to

the motion of tip 140' during lancing, while the direction of applying a force for

actuating lancet 800 is parallel to the direction of movement of lancet tip 140'.

Since the actuation of lancet 800 and the direction of travel of lancet tip 140'

are disposed parallel one to the other, there is no opportunity for use of a frangible

part out of the line of travel of lancet tip 140'. For this reason, prior to use, lancet 800

is preferably packaged inside a sealed package 802, an example of which is seen in

Figure 24. Such packages are well known in the medical industry and are commonly

used to protect lancets in transport and prior to use.

Referring to Figure 25, lancet 800 comprises an outer housing 804 and an

inner housing 806. Inner housing 806 is made to slide within outer housing 804.

Inner housing 806 comprises a plunger or push end 808 and an end 810. End 810

comprises a lancet tip 140' exit and reentry port 812 and a raised shroud 814. In

combination, inner housing 806 and outer housing 804 comprise a lancet and lancet

activation mechanism similar in form and function to that comprising hump 756 and

sloped surface 760, except that the lancet activation mechanism is aligned to operate

as outer housing 804 and inner housing 806 are moved relative to each other, with the

outer housing 804 moving away from a lance site.

Outer housing 804 comprises a rim 816, which provides a housing 804

retarding part which permits outer housing 804 to be retracted from the lance site as

plunger 808 is moved relative to outer housing toward the lance site to actuate lancet

800. The state of lancet 800 following a lancing procedure is seen in Figure 26.

A lancet 900 comprising an additional mechanical advantage that provides an

additional force to frange a hub 50" is seen in Figures 27 and 28. Similar to lancets

750, 800 and 850, lancet 900 comprises an outer housing 902 and an inner housing

904 which act as inner housing 904 is moved relative to outer housing 902 to actuate

the lancet. The source of the mechanical advantage is a pivot pin 906 medially and

proximally disposed relative to a lancet blade 500', disposed within inner housing 902.

Outer housing 902 further comprises a curved surface and associated part 908

which is juxtaposed to a lance site during a lancing procedure. Part 908 comprises a

lancet tip exit and reentry portal 910, which also acts as a shroud. Outer housing 902

also comprises an opening 912, which permits a portion 914 of inner housing 904 to

be slidably translated during activation of lancet 900.

Inner housing 904 comprises a lancet compartment 40", which is similar to

cavity 40'. Inside compartment 40", inner housing 904 comprises a hub 50", a spring

110 and a lancet blade 500'. Lancet blade 500' comprises a medially disposed blade

stem 915 and a blade tip 140". Exterior to compartment 40", inner housing 904

comprises an aperture disposed about pivot pin 916, which provides a fulcrum and, in

combination with the effective lever arm provided by portion 914, increases the

mechanical advantage as portion 914 is translated inside outer housing 902 through

opening 912. Inner housing 904 further comprises blade guides 918, 920, 922 and

924. Note that guide 924 is separated into two parts, making way for an anchor slot

62 for lower spring end 122. Inner housing 904 also comprises a curved surface 926,

which is an arc of a circle drawn with pivot pin 906 at the center. Note that the

curvature of outer housing part 908 conforms with the curvature of surface 926.

Curved surface 926 comprises an exit and reentry port 928 for lancet tip 140".

Before activating lancet 900 by translating portion 914 into outer housing 902,

an outer periphery 930 is preferably sealed against an inner surface portion of part 908

to permit lancet 900 to be transported and stored without additional packaging. In a

manner similar to the frange mechanism provided by hump 756 and surface 760, outer

housing 902 and inner housing 904 act in concert to frange hub 50" free and to

activate lancet 900 as inside housing 904 rotates about pivot pin 906 to bring port 928

in alignment with portal 910 and to cause lancet tip 140" to traverse outward to the

lance site and then return to a secure rest state as seen in Figure 28.

Blade 500' differs from blade 500 in two significant ways. First tip 140"

comprises a wider, but shallower cutting edge. Such a blade is useful in longer but

more superficial cuts, such as cuts on an infant. Second stem 915 is medially

disposed upon blade 500'. The medial position is particularly important in a device

which rotates about a pivot pin as lancet 900 does.

It is currently preferred that materials used for lancets 700, 750, 800, and 900

are the same as those listed for lancet strip 600.

The invention my be embodied in other specific forms without departing from

the spirit or essential characteristics thereof. The present embodiments are therefore

to considered in all respects as illustrative and not restrictive, the scope of the

invention being indicated by the appended claims rather than by the foregoing

description, and all changes which come within the meaning and range of equivalency

of the claims are therefore intended to be embraced therein.

What is claimed is: