U.S. patent application number 17/331339 was filed with the patent office on 2022-02-10 for body fluid sampling device - sampling site interface.
The applicant listed for this patent is Intuity Medical, Inc.. Invention is credited to Jeffrey L. Emery, Raul Escutia, Jeffrey M. Jones, Kelley J. Lipman, Craig M. Litherland, Michael F. Tomasco.
Application Number | 20220039711 17/331339 |
Document ID | / |
Family ID | |
Filed Date | 2022-02-10 |
United States Patent
Application |
20220039711 |
Kind Code |
A1 |
Escutia; Raul ; et
al. |
February 10, 2022 |
BODY FLUID SAMPLING DEVICE - SAMPLING SITE INTERFACE
Abstract
An arrangement for producing a sample of body fluid from a wound
opening created in a skin surface at a sampling site includes: a
housing, the housing comprising a first opening; a skin interface
member disposed in the first opening, the skin interface member
comprising an inner member having a second opening, and an outer
member at least partially surrounding the inner member and attached
to the first opening; and at least one skin-penetration member
configured and arranged to project within the second opening.
Arrangements having alternatively constructed skin interface
members are also described.
Inventors: |
Escutia; Raul; (Sunnyvale,
CA) ; Litherland; Craig M.; (San Jose, CA) ;
Emery; Jeffrey L.; (Redwood City, CA) ; Jones;
Jeffrey M.; (Sunnyvale, CA) ; Tomasco; Michael
F.; (Morgan Hill, CA) ; Lipman; Kelley J.;
(Livermore, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Intuity Medical, Inc. |
Fremont |
CA |
US |
|
|
Appl. No.: |
17/331339 |
Filed: |
May 26, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15826418 |
Nov 29, 2017 |
11045125 |
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17331339 |
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12457085 |
Jun 1, 2009 |
9833183 |
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15826418 |
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61129025 |
May 30, 2008 |
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International
Class: |
A61B 5/15 20060101
A61B005/15; A61B 5/151 20060101 A61B005/151; A61B 5/157 20060101
A61B005/157 |
Claims
1-48. (canceled)
49. An arrangement to assist in obtaining a body fluid sample from
a sampling site of a user, the arrangement comprising: a housing;
and a plate releasably mountable to the housing, the plate
comprising a skin interface member attached thereto, the skin
interface member comprising an inner member having an opening
configured to receive the sampling site of a user, and an outer
member at least partially surrounding the inner member, wherein the
outer member is coplanar with the plate and is configured to flex
more than the inner member upon application of force to the skin
interface member.
50. The arrangement of claim 49, wherein the inner member has a
first hardness and the outer member has a second hardness that is
less than the first hardness.
51. The arrangement of claim 49, wherein the inner member and the
outer member are integral.
52. The arrangement of claim 49, wherein the outer member is formed
from an elastomer, a silicone rubber, or a soft plastic and the
inner member is formed from a metal, an elastomer, or a
ceramic.
53. The arrangement of claim 49, wherein the skin interface member
comprises a punching or cutting mechanism.
54. The arrangement of claim 53, wherein the punching or cutting
mechanism comprises a downwardly projecting member.
55. The arrangement of claim 49 further comprising a cartridge
configured to be received in the housing, wherein the cartridge
comprises at least one skin-penetration member.
56. The arrangement of claim 55, wherein the cartridge further
comprises at least one analyte quantification member.
57. The arrangement of claim 56, wherein the cartridge comprises a
plurality of skin-penetration members, a plurality of actuators,
and a plurality of analyte quantification members operatively
arranged such that multiple tests can be performed using the
arrangement without replacing the cartridge.
58. The arrangement of claim 55, wherein the cartridge comprises an
outer surface, and wherein the skin interface member is configured
to form a seal with the outer surface of the cartridge upon being
pressed against skin of the user.
59. An arrangement to assist in obtaining a body fluid sample from
a sampling site of a user, the arrangement comprising: a housing;
and a plate releasably mountable to the housing, the plate
comprising a skin interface member coupled thereto, the skin
interface member comprising an inner member having an opening, and
an outer member at least partially surrounding the inner member,
wherein a perimeter portion of the outer member is affixed to the
plate, the outer member is substantially flat, and the outer member
is configured to flex more than the inner member upon application
of force to the skin interface member.
60. The arrangement of claim 59, wherein the inner member has a
first hardness and the outer member has a second hardness that is
less than the first hardness.
61. The arrangement of claim 59, wherein the inner member and the
outer member are integral.
62. The arrangement of claim 59, wherein the outer member is formed
from an elastomer, a silicone rubber, or a soft plastic and the
inner member is formed from a metal, an elastomer, or a
ceramic.
63. The arrangement of claim 59, wherein the skin interface member
comprises a punching or cutting mechanism.
64. The arrangement of claim 63, wherein the punching or cutting
mechanism comprises a downwardly projecting member.
65. The arrangement of claim 59 further comprising a cartridge
configured to be received in the housing, wherein the cartridge
comprises at least one skin-penetration member.
66. The arrangement of claim 65, wherein the cartridge further
comprises at least one analyte quantification member.
67. The arrangement of claim 66, wherein the cartridge comprises a
plurality of skin-penetration members, a plurality of actuators,
and a plurality of analyte quantification members operatively
arranged such that multiple tests can be performed using the
arrangement without replacing the cartridge.
68. The arrangement of claim 65, wherein the cartridge comprises an
outer surface, and wherein the skin interface member is configured
to form a seal with the outer surface of the cartridge upon being
pressed against skin of the user.
69. An arrangement to assist in obtaining a body fluid sample from
a sampling site of a user, the arrangement comprising: a housing; a
plate releasably mountable thereto, wherein the plate is fixed
relative to the housing when mounted thereon; and a skin interface
member coupled to the plate, the skin interface member comprising
an inner member having an opening configured to receive the
sampling site, and an outer member at least partially surrounding
the inner member, wherein the outer member is configured to flex
more than the inner member upon application of force to the skin
interface member.
70. The arrangement of claim 69, wherein the inner member has a
first hardness and the outer member has a second hardness that is
less than the first hardness.
71. The arrangement of claim 69, wherein the inner member and the
outer member are integral.
72. The arrangement of claim 69, wherein the outer member is formed
from an elastomer, a silicone rubber, or a soft plastic and the
inner member is formed from a metal, an elastomer, or a
ceramic.
73. The arrangement of claim 69, wherein the skin interface member
comprises a punching or cutting mechanism.
74. The arrangement of claim 73, wherein the punching or cutting
mechanism comprises a downwardly projecting member.
75. The arrangement of claim 69 further comprising a cartridge
configured to be received in the housing, wherein the cartridge
comprises at least one skin-penetration member.
76. The arrangement of claim 75, wherein the cartridge further
comprises at least one analyte quantification member.
77. The arrangement of claim 76, wherein the cartridge comprises a
plurality of skin-penetration members, a plurality of actuators,
and a plurality of analyte quantification members operatively
arranged such that multiple tests can be performed using the
arrangement without replacing the cartridge.
78. The arrangement of claim 75, wherein the cartridge comprises an
outer surface, and wherein the skin interface member is configured
to form a seal with the outer surface of the cartridge upon being
pressed against skin of the user.
Description
FIELD
[0001] The present invention relates to devices, arrangements and
methods involving body fluid acquisition. In certain embodiments,
the present invention is directed to an interface member for
contacting the skin of the user of a body fluid sampling
device.
BACKGROUND
[0002] In this specification where a document, act or item of
knowledge is referred to or discussed, this reference or discussion
is not an admission that the document, act or item of knowledge or
any combination thereof was at the priority date, publicly
available, known to the public, part of common general knowledge,
or otherwise constitutes prior art under the applicable statutory
provisions; or is known to be relevant to an attempt to solve any
problem with which this specification is concerned.
[0003] According to the American Diabetes Association, diabetes is
the fifth-deadliest disease in the United States. Since 1987 the
death rate due to diabetes has increased by 45 percent. There are
an estimated 20.8 million children and adults in the United States,
or 7% of the population, who have diabetes. The total annual
economic cost of diabetes in 2007 was estimated to be $174 billion.
This is an increase of $42 billion since 2002. This 32% increase
means the dollar amount has risen over $8 billion each year.
[0004] A critical component in managing diabetes is frequent blood
glucose monitoring. Currently, a number of systems exist for
self-monitoring by the patient. Most fluid analysis systems, such
as systems for analyzing a sample of blood for glucose content,
comprise multiple separate components such as separate lancing,
transport, and quantification portions. These systems are bulky,
and often confusing and complicated for the user. The systems
require significant user intervention.
[0005] Technology in the field of self-monitoring of blood glucose
has placed the burden of acquiring sufficient blood for conducting
a test on the user of the technology. Earlier versions of
consumer-oriented self-monitoring products usually required many
microliters of blood.
[0006] Lancing devices and the lancets themselves have also evolved
somewhat over the past few decades. Some lancing mechanisms may
produce relatively less pain by either (1) projecting the lancet in
and out of the skin in a more straight path and thus reducing
stimulation of percutaneous nerves which provide the pain stimulus;
and (2) offering depth control in the lancing device so that the
user may balance the expression of sufficient blood against the
level of pain. Furthermore, lancet manufacturers offer a variety of
lancet sizes, lengths, and tip bevel patterns with some companies
claiming that their lancet is less painful than others.
[0007] What remains clear is that the most testers, when lancing at
the finger, often must put down the lancing device after creating a
wound and apply pressure near the finger tip in order to produce
sufficient blood for the test strip in the meter. Many instructions
for use of conventional meter systems specifically prescribe that
the user perform this "milking" process because without it, many
will not spontaneously produce the required volume. Applicants have
observed this phenomenon in the use of commonly available
commercial sampling and meter systems. In one study, when a trained
professional lanced the finger tips of 16 volunteer diabetic
subjects at the maximum depth setting on commercially available
device under controlled conditions, only 15% of lanced sites
spontaneously produced sufficient blood for the meter to accurately
measure glucose levels.
[0008] Conventional sampling devices and methods are overly reliant
upon user intervention, such as milking, in order to consistently
express a sufficient quantity of blood from the wound site. Thus,
it would be advantageous to provide constructions, arrangements and
techniques that improved the ability to consistently and
spontaneously obtain an adequate sample of body fluid from a
sampling site on the skin of the user.
SUMMARY OF THE INVENTION
[0009] According to the present invention, there are provided
constructions, arrangements and techniques that may address one or
more of the above-mentioned objectives. However, the present
invention is not limited to the context of blood sampling performed
for the purposes of monitoring glucose concentration. Numerous
alternative applications or uses for the concepts described herein
are contemplated.
[0010] According to certain aspects of the present invention, there
are provided constructions, arrangements and techniques that may
optionally provide one or more of the following benefits or
advantages: increase in the likelihood of a spontaneous production
of blood from a wound created by a skin-penetrating member;
providing the user with a tactile and visual aid for correctly
positioning the device or arrangement; creating a sufficient seal
between the skin at the sampling site and one or more components of
the arrangement; and reduction or mitigation of pain sensation.
[0011] As used herein "digital" means fingers or toes. "Digital
body fluid" means expression of body fluid from a wound created on
the fingers or toes, and encompasses lancing sites on the dorsal or
palm side of the distal finger tips.
[0012] As used herein, "body fluid" encompasses whole blood,
intestinal fluid, and mixtures thereof.
[0013] As used herein "integrated device" or "integrated meter"
means a device or meter that includes all components necessary to
perform sampling of body fluid, transport of body fluid,
quantification of an analyte, and display of the amount of analyte
contained in the sample of body fluid.
[0014] It is to be understood that reference herein to first,
second, third and fourth components (etc.) does not limit the
present invention to embodiments where each of these components is
physically separable from one another. For example, a single
physical element of the invention may perform the functions of more
than one of the claimed first, second, third or fourth components.
Conversely, a plurality of separate physical elements working
together may perform the functions of one of the claimed first,
second, third or fourth components. Similarly, reference to first,
second (etc.) method steps does not limit the invention to only
separate steps. According to the invention, a single method step
may satisfy multiple steps described herein. Conversely, a
plurality of method steps could, in combination, constitute a
single method step recited herein. In addition, the steps of the
method are not necessarily limited to the order in which they are
described or claimed herein.
[0015] According to one aspect, the present invention is directed
to an arrangement for producing a sample of body fluid from a wound
opening created in a skin surface at a sampling site, the
arrangement comprising: a housing, the housing comprising a first
opening; a skin interface member disposed in the first opening, the
skin interface member comprising an inner member having a second
opening, and an outer member at least partially surrounding the
inner member and attached to the first opening; and at least one
skin-penetration member configured and arranged to project within
the second opening.
[0016] According to another aspect, the present invention is
directed to an arrangement for producing a sample of body fluid
from a wound opening created in a skin surface at a sampling site,
the arrangement comprising: a housing, the housing comprising a
first opening; a skin interface member disposed in the first
opening, the skin interface member comprising an inner portion
having a second opening, the inner portion further comprising a
first projection along the second opening and a second projection
along the second opening, the first and second projections
extending in opposite directions, and the skin interface member
further comprising an outer portion at least partially surrounding
the inner portion and attached to the first opening; at least one
skin-penetration member configured and arranged to project within
the second opening; a cartridge disposed within the housing,
wherein the at least one skin-penetration member is disposed within
the cartridge.
[0017] According to a further aspect, the present invention
provides an arrangement for producing a sample of body fluid from a
wound opening created in a skin surface at a sampling site, the
arrangement comprising: a housing, the housing comprising a first
opening; a skin interface member disposed in the second opening,
the skin interface member comprising a longitudinally tapered
cylindrical member having a first opening constructed an arranged
to be contacted by the skin, the inner diameter of the cylinder
decreasing along the longitudinal direction away from the second
opening, the longitudinally tapered cylindrical member comprising a
plurality of longitudinal slits thereby forming a plurality of
longitudinal sections, the longitudinally tapered cylindrical
member constructed and arranged so as to be movable within the
first opening upon pressing against the surface of the skin at the
second opening thereby forcing the longitudinal sections radially
inward; and at least one skin-penetration member configured and
arranged to project within the second opening.
[0018] According to yet another aspect, the present invention
provides an arrangement for producing a sample of body fluid from a
wound opening created in a skin surface at a sampling site, the
arrangement comprising: a housing, the housing comprising a first
opening; a skin interface member disposed in the first opening, the
skin interface member comprising a plurality of concentric
telescoping sections, including an innermost section, the innermost
section having a second opening, the innermost member constructed
and arranged so as to be pressed against the surface of the skin at
the second opening; and at least one skin-penetration member
configured and arranged to project within the second opening.
[0019] According to an additional aspect, the present invention
provides an arrangement for producing a sample of body fluid from a
wound opening created in a skin surface at a sampling site, the
arrangement comprising: a housing, the housing comprising a first
opening; a skin interface member disposed in the first opening, the
skin interface member comprising a plurality of rotatable members
defining a gap therebetween, the plurality of rotatable members
constructed an arranged such that rotatable members are forced
toward one another upon being pressed against the skin thereby
decreasing the gap and pinching the skin; and at least one
skin-penetration member configured and arranged to project within
the gap.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0020] The following description of preferred embodiments can be
read in connection with the accompanying drawings in which like
numerals designate like elements and in which:
[0021] FIG. 1 is a cut away side view of an arrangement constructed
according to the present invention.
[0022] FIG. 2 is a partial bottom perspective view of the
arrangement of FIG. 1.
[0023] FIG. 3 is a partial sectional view of an alternative
arrangement formed according to the present invention.
[0024] FIG. 4 is a partial sectional view of the arrangement of
FIG. 3, shown in a first state.
[0025] FIG. 5 is a partial sectional view of the arrangement of
FIG. 3, shown in a second state.
[0026] FIG. 6 is a partial sectional view of another arrangement
formed according to an alternative embodiment of the present
invention.
[0027] FIG. 7 is a partial cut away view of an arrangement formed
according to a further alternative embodiment of the present
invention.
[0028] FIG. 8 is a partial cut away view of the arrangement of FIG.
7, after having been pressed against the skin of a user.
[0029] FIG. 9 is a partial perspective view of an alternative
arrangement of the present invention.
[0030] FIG. 10 is a partial side cut away view of the arrangement
of FIG. 9.
[0031] FIG. 11 is a partial side cut away view of the arrangement
of FIG. 9, after having been pressed against the skin of the
user.
[0032] FIG. 12 is a partial cut away view of an arrangement formed
according to yet another alternative embodiment of the present
invention.
[0033] FIG. 13 is a partial cut away view of the arrangement of
FIG. 12, after having been pressed against the skin of the user
[0034] FIG. 14 is a perspective view of an arrangement of a further
embodiment of the present invention.
[0035] FIG. 15 is a partial side view of the arrangement of FIG.
14.
[0036] FIG. 16 is a partial side view of the arrangement of FIG.
14, after having been pressed against the skin of the user.
[0037] FIG. 17 is a sectional view of an arrangement formed
according to another aspect of the present invention.
[0038] FIG. 18 is a sectional view of the arrangement of FIG. 17,
shown in a different state.
[0039] FIG. 19 is a partial perspective view of an arrangement
formed according to an additional embodiment of the present
invention, in a first state.
[0040] FIG. 20 is a partial perspective of the arrangement of FIG.
19, in a second state.
[0041] FIG. 21 is a partial perspective of the arrangement of FIG.
19, in a third state.
[0042] FIG. 22 is a partial perspective view of an arrangement
formed according to a further embodiment of the present invention,
in a first state.
[0043] FIG. 23 is a partial perspective of the arrangement of FIG.
22, in a second state.
[0044] FIG. 24 is a partial perspective view of an arrangement
formed according to an additional alternative aspect of the present
invention.
[0045] FIG. 25 is a perspective view of an arrangement formed
according to a further alternative embodiment of the present
invention.
[0046] FIG. 26 is a perspective view of a portion of the
arrangement of FIG. 25.
DETAILED DESCRIPTION
[0047] According to a first aspect of the present invention, there
are provided arrangements and techniques for reliably expressing
body fluid from a digit or from an alternate site such as the
forearm, thigh, etc. For example, according to the present
invention, arrangements and techniques are provided which
consistently and reliably express an amount of body fluid that is
sufficient to perform an analysis to quantify the amount of an
analyte (e.g., glucose, bilirubin, alcohol, controlled substances,
toxins, hormones, proteins, etc.) contained therein.
[0048] One embodiment of an arrangement 10 of the type described
above is illustrated in FIGS. 1-2. As illustrated therein, the
arrangement 10 may be in the form of an integrated meter 11. It
should be understood that any of the arrangements or embodiments
described herein may be used in connection with an integrated
meter, which may have one or more of the features of the integrated
meter 11 of the embodiment illustrated in FIG. 1. However, it
should be made clear that the present invention is not so limited.
The concepts and arrangements described herein are believed to be
applicable to a number of different devices and systems, such as
simple lancing devices, multiple component systems, and the
like.
[0049] The arrangements described herein may be used or applied to
a skin surface 12 at a suitable sampling site 14. One suitable
sampling site 14 is on a digit D. However, the arrangements
described herein may be used or applied to any skin surface at any
suitable sampling site which may include alternative sampling sites
such as the forearm, thigh, etc.
[0050] According to the illustrated embodiment, the arrangement 10
includes a housing 16. The housing 16 may have any suitable shape
or configuration, and is not limited to the shape and configuration
illustrated. According to one alternative construction, the housing
16 may comprise at least a portion of a removable cap (not shown).
The shape of the housing 16 may be contoured such that it is easily
grasped by the hand of the user. The housing 16 can be constructed
of any suitable material. For example, the housing 16 may be
constructed of a polymeric or metallic material. The housing may
comprise a first opening 18 disposed therein. A skin interface
member 20 constructed according to the principles of the present
invention may be disposed in the first opening 18 and provided with
an attachment 22 to the housing 16. According to one embodiment,
the attachment 22 is readily removable from the opening 18 in the
housing 16, thereby allowing the user to remove an existing skin
interface member 20 and insert a replacement or alternatively
constructed skin interface members 20.
[0051] As illustrated in FIG. 1, the thickness of the skin
interface member 20 defines a separation distance (e.g., SD, FIG.
3) between the housing 16 and the surface of the skin 12. Thus,
this separation distance can be changed by changing the thickness
of the skin interface member, which in turn will alter the depth of
penetration of a skin penetration member traveling from within the
housing and into the surface of the skin, as will be described in
greater detail below. Therefore, according to the principles of the
present invention, a number of different skin interface members 20
having different thicknesses can be provided to the user so that an
appropriate penetration depth of a skin penetration member can be
selected by substituting a skin interface member 20 having an
appropriate thickness.
[0052] The arrangements described herein may further optionally
include a catalyst to assist in the sample acquisition process by
enhancing or facilitating perfusion of body fluid at a sampling
site. At least one of several catalysts may be utilized or included
in the arrangement of the present invention. Possible catalysts
include, heat, pressure, vacuum, vibration, and topical drugs
(which induce vasodilatation and increases the blood or body fluid
available at the lancing site). These catalysts may be applied
before, during, after lancing, or in combination with some or all
three, to facilitate expression of sufficient quantity of body
fluid for determination of the concentration of an analyte
contained therein (e.g., glucose).
[0053] Skin interface member contact pressure is another catalyst
and can be varied by a number of possible techniques. One such
technique is to vary the size of an opening of the skin interface
member. Another form of pressure catalyst can take the form of a
squeezing or pinching member(s), as illustrated by examples which
will be described herein.
[0054] Heat is another optional catalyst. Applying heat, thereby
increasing the skin temperature at the wound site, increases blood
production. Possible implementations of heat include infrared (IR)
lights, or resistive elements to heat the skin.
[0055] Another catalyst is vacuum pressure. According to certain
embodiments, a light vacuum (e.g., 3-8 in. Hg) is applied to
surface of the skin 12 at the sampling site 14 before, during,
and/or after lancing. Several embodiments for applying vacuum to
the wound site are contemplated. One embodiment uses a motor driven
pump 23 (FIG. 1) to apply vacuum to the area of the skin 12 at the
sampling site 14. Alternative embodiments include using
individually packaged vacuum chambers to apply vacuum, or using a
rigid syringe like mechanism to apply vacuum.
[0056] According to the principles of the present invention, one or
more of the above-described catalysts can be used in combination
with each other, either concurrently or sequentially.
[0057] A skin interface member 20 may take any suitable form. For
example, according to the illustrated embodiment, the skin
interface member 20 comprises an outer member 24, which may include
the aforementioned attachment structure 22 that affixes the skin
interface member 20 to the housing, and an inner member 26. The
inner member 26 comprises a second opening 28. The second opening
28 can take any suitable size and/or geometry. For example, the
second opening 28 can be substantially circular or ovular, and have
a diameter of about 3 mm-8 mm. According to a further alternative
embodiment, the second opening 28 has a diameter of about 6 mm. The
outer member 24 at least partially surrounds the inner member 26
and is attached thereto. Any suitable form of attachment is
contemplated. For example, the outer member 24 and inner member 26
may be connected via an adhesive, or maybe integrated together via
a co-molding process or similar integration technique. According to
one embodiment, the inner member 26 has a first hardness, and the
outer member 24 has a second hardness, wherein the first hardness
is greater than the second hardness. The inner and outer members
26, 24 can be formed from any suitable materials. For example, the
outer member 24 can be formed from an elastomer, silicone rubber,
or soft plastic. The inner member 26 may be formed from a metal,
plastic, relatively hard elastomer or ceramic.
[0058] Applicants have discovered that by providing the skin
interface member 20 with a relatively harder inner member 26, a
number of advantages are obtained. For instance, it has been
observed that a skin interface member having a relatively harder
inner member forms a better more reliable seal with the surface of
the skin compared to a skin interface member formed entirely from a
relatively soft pliable material. It has also been observed that
many users prefer the tactile feel of the relatively hard inner
member 26 when applied to the surface of the skin. This improved
tactile feel also facilitates the correct positioning of the skin
interface member for body fluid sampling.
[0059] The arrangements described herein may have a number of
additional optional features. For example, at least one of the
outer or inner members 24, 26 may have a construction so as to emit
visible light thereby facilitating use of the arrangements in
low-light conditions. Alternatively, the housing 16 may be provided
with such a mechanism for emitting visible light. Optionally, the
area of the housing in proximity to skin interface member 20 may be
provided with the aforementioned light-emitting mechanism. Any
number of mechanisms that emit visible light can be provided. For
example, a potion of the housing 16 or at least one of the outer or
inner members 24, 26 may be formed from a fluorescent material.
Alternatively, one or more light emitting elements, such as light
emitting diodes, schematically illustrated as elements 30 and 30',
can be mounted within at least one of the housing 16 or outer and
inner members 24, 26.
[0060] One or more members for generating heat may be incorporated
into the skin interface member 20 of the present invention. Thus,
for example, resistive heating elements, also generically
illustrated as element 30, may be embedded within at least one of
the outer and inner members 24, 26.
[0061] At least one of the outer and inner members 24, 26 may be
provided with a textured surface for improving the tactile feel
when applied to the skin of the user.
[0062] At least one sensor, generically illustrated as element 31,
may also be provided for detecting contact with the skin of the
user, and/or the amount of pressure exerted between the skin and
the interface member 20 and/or the arrangement 10. Thus, for
example, based on information derived from the sensor 31, the
arrangement 10 can provide audible and/or visible feedback to the
user to indicate when a target or optimal pressure is being applied
to the skin 12 at the sampling site 14, and/or when the pressure
being applied by the user lies outside of the target pressure value
or range. Moreover, the arrangement 10 can be configured to use
information derived from the sensor 31 to initiate one or more
functions or operations. For example, an automated test sequence
can be initiated once a minimum amount of force is sensed between
the skin and the interface member 20, or if contact with the skin
is sensed for a predetermined period of time. According to a
further alternative embodiment, if no contact with the skin is
sensed, the arrangement may automatically initiate a stand-by or
shut down mode. Optionally, if no contact with the skin is sensed,
the arrangement may automatically cover or close the second opening
28, so as to shield the inside of the arrangement 10 from the
external environment and/or ambient light. The sensor can be
located in any suitable portion of the arrangement, such as in the
outer or inner member 24, 26, and/or the housing 16. The at least
one sensor 31 can comprise, for example, well-known pressure
transducer technology, capacitive touch sensing technology,
resistive touch sensing technology, simple dome switch, or other
micro switch, and the arrangement may further comprise additional
signal processing and control components that are conventional in
the art.
[0063] According to a further optional aspect, at least the inner
member 26 of the skin interface member 20 can be provided with a
hydrophobic property. This can be accomplished by forming the inner
member entirely of a hydrophobic material, or by providing a
hydrophobic coating onto one or more surfaces of the inner member
26. By providing the inner member 26 with a hydrophobic property,
any body fluid coming into contact with the hydrophobic material of
inner member skin interface member 20 will be repelled, preferably
in a direction that leads it toward the inside of the housing 16,
or it may be collected for performing an assay. According to a
further optional construction, the skin penetration member (e.g.,
34, FIG. 1) may be provided with a hydrophilic property, optionally
via a hydrophilic coating applied thereto, which would attract body
fluid in its vicinity. Providing the inner member with a
hydrophobic property may also act to repel body fluid in close
proximity thereto, thereby also having a possible effect of causing
the body fluid to pool or form a well-defined drop on the surface
of the skin. This effect, combined with the hydrophilic property of
the skin penetration member can also promote the likelihood of
efficient collection in transport of a sample of body fluid by the
skin penetration member.
[0064] An additional optional feature of the arrangement 10
includes a cartridge 32. The cartridge 32 may include one or more
components which are utilized to collect, transport, and perform an
assay on a sample of body fluid, as will be described in more
detail below. When the arrangement 10 includes such a cartridge 32,
the skin interface member 20 may be provided with at least one
contoured surface 33 which is intended to form a seal when pressed
against the cartridge 32. The seal formed by the surface 33 against
the cartridge 32 may optionally be substantially vacuum-tight.
Thus, when vacuum is utilized as an optional catalyst, the seal
formed by the surface 33 pressing against the cartridge 32 allows
for the creation of a vacuum in the area of the skin 12 at the
sampling site 14.
[0065] The arrangement 10 may further includes at least one skin
penetration member 34. The at least one skin penetration member 34
can take any suitable form. For example, the at least one skin
penetration member can comprise a solid lancet or a hollow needle.
Conventional arrangements often require separate mechanisms for
drawing a sample of blood to the surface of the skin and for
transporting the sample to a reaction chamber. The arrangements of
the present invention can optionally include a skin-piercing
element in the form of a hollow needle to both create a wound
opening and transport the sample, thereby greatly simplifying and
improving the effectiveness of the arrangement 10.
[0066] According to one optional embodiment, the skin-penetration
member(s) 34 can be in the form of a so-called "microneedle." As
the name implies, microneedles are characterizable by their
relatively small outer diameters. For example, a microneedle, as
the term is utilized herein, may encompass a skin-penetration
member having an outside diameter which is on the order of 40-200
.mu.m. When the microneedle is hollow and comprises an inner lumen,
the inside diameter can vary, for example, having an inside
diameter on the order of 25-160 .mu.m. Needles are also
characterizable in the art by reference to the "gage." By way of
illustration, and consistent with the above description,
microneedles having a gage ranging from 26-36 are clearly
comprehended by the present invention. Certain advantages may be
gleaned from the use of such microneedles as the skin-penetration
member. In particular, due to their small size, the size of the
wound left upon entry into the skin is relatively small, thereby
minimizing the pain associated with such needle insertions and
allowing for a quicker healing process. However, the present
invention is certainly not limited to the use of such microneedles.
Thus, for example, according to one possible alternative
embodiment, the skin penetration member(s) comprise hollow needles
having a gage of about 20-25, or comprising hollow needles having
an inner diameter of about 0.007 inches and an outer diameter of
about 0.020 inches.
[0067] The at least one skin-penetration member 34 can be formed of
any suitable material, such as metal, plastic, glass, etc.
Optionally, the at least one skin penetration member can be in
communication with an analyte quantification member 36. In further
alternative embodiments, the analyte quantification member 36 may
include an assay pad 38 comprising a reagent that changes color
upon reaction with a target analyte, as known per se to those
skilled in the art. The assay pad 38 is in fluid communication with
the sample of body fluid. The assay pad 38 can be analyzed by a
detector 42, such as an optical sensor, that forms part of the
arrangement 10. Alternatively, the assay pad 38 can be removed from
the arrangement 10 and inserted into a separate device, such as an
electrochemical or photometric meter.
[0068] The at least one skin penetration member 34, and/or the
analyte quantification member 36 may optionally be attached to an
actuation element 40. The actuation element 40 can take any
suitable form. For example, the actuation element 40 may comprise a
mechanical, electrical or pneumatic element. According to the
illustrated embodiment, the actuation element 40 is in the form of
a mechanical spring. The actuation element 40 drives the at least
one skin-penetration member 34 into the skin 12 at the sampling
site 14, as indicated by the broken line outline of the
skin-penetration member 34 as illustrated in FIG. 1.
[0069] As further illustrated in FIG. 1, the arrangement 10 can
comprise a plurality of skin penetration members 34, analyte
quantification members 36 and actuators 40 mounted within the
cartridge 32. Thus, the arrangement 10, particularly when in the
form of an integrated meter 11, is capable of performing a number
of assays on collected body fluid samples in a fully self-contained
a manner. After a number of assays have been performed which
correspond to the number of skin penetration members 34, analyte
quantification members 36 and actuators 40, the cartridge 32 can be
removed, discarded, and replaced with a new cartridge 32.
[0070] According to certain embodiments of the present invention,
the arrangement 10, or integrated meter 11, can operate in an
automatic or semi-automatic manner. For example, a user may place
the skin interface member 20 over the surface of the skin 12 and
when the user is ready to produce a sample of body fluid and/or
perform an assay, the user initiates the process by, for example,
pressing a button, touch screen, or other device interface (not
shown). This can initiate a programmed sequence of events in the
arrangement or integrated meter which may include one or more of
actuation of a catalyst, and driving the skin-penetration member 34
into the skin. At a predetermined time, the catalyst device 14 is
deactivated. This mode of operation can be characterized as
"semi-automatic" in that sequence of events is manually initiated
by the user.
[0071] According to one alternative, the mode of operation can be
fully automatic. For example, the user places the skin interface
member 20 over the skin 12 at a suitable sampling site. The
arrangement 10, or integrated meter 11, can be provided with one or
more sensors, such as sensors generically illustrated as element
31, that detect and verify that the skin interface member is
properly located and ready for the sampling procedure to begin.
Once this state has been sensed, the device automatically activates
a programmed sequence of events in the device which may include one
or more of activation of a catalyst, and driving the
skin-penetration member 34 into the skin. At a subsequent
predetermined time, the catalyst device 14 is deactivated. The
catalyst device can be deactivated before, during or after the
skin-piercing member is driven into the skin.
[0072] The skin interface member 20 may be provided with a suitable
construction so as to provide an adjustable mechanism for altering
the above-mentioned separation distance between the housing and the
surface of the skin. An illustrative example of one such
arrangement 10' is contained in FIGS. 3-5. The arrangement 10'
depicted in FIGS. 3-5 can be similar to the arrangement 10
previously described herein. According to the illustrative modified
arrangement 10', the position of the skin interface member 20'
relative to the housing 16' can be adjusted. Thus, for example, the
housing 16' can be provided with an upwardly projecting flange 17
having a threaded inner surface 17a. The modified skin interface
member 20' can be provided with an outer member 24' comprising an
attachment 22' which is relatively movable with respect to the
housing 16'. The modified skin interface member 20' may further
include a relatively hard inner member 26' which is attached to the
relatively softer outer member 24', and further includes a threaded
outer surface 26a which mates with the threaded surface 17a of the
housing 16'. Thus, by rotating the skin interface member 20' in a
particular direction, the inner member 26', as well as the attached
outer member 24' of the skin interface member 20' travels either up
or down, as indicated by arrows U, D. As further illustrated in
FIG. 4, travel in the direction of arrow U causes an increase in
the separation distance SD, thereby reducing the penetration depth
of a skin penetration member 34. Conversely, as illustrated in FIG.
5, travel in the direction of arrow D causes a reduction in the
separation distance SD, thereby increasing the penetration depth of
a skin penetration member 34. It should be understood that the
arrangement 10' may include any of the features described in
connection with any of the other embodiments described herein,
including the arrangement 10 of FIGS. 1-2.
[0073] According to a further alternative construction of the
present invention, a further modified arrangement 10'' can be
provided along the lines of the arrangement illustrated in FIG. 6.
As illustrated therein, the arrangement 10'' is constructed in a
manner which is somewhat similar to the previously described
arrangements 10, 10'. According to the arrangement 10'' illustrated
in FIG. 6, the skin interface member 20'' is provided with a shape
and/or configuration which buckles or provides a similar tactile
sensation to the user upon pressing the skin interface member 20''
in the direction of arrow D'. Thus, as illustrated, the skin
interface member 20'' can be provided with a relatively soft outer
portion 24'' that has a collapsible or flexible dome-like
configuration. Thus, when the relatively hard inner member 26'' is
pressed in the direction of arrow D' the attached outer portion
24'' flexes or deforms in the manner illustrated by the broken
lines appearing in FIG. 4. This flexing or deformation produces a
buckling sensation/sound, thereby providing tactile/audible
feedback to the user with respect to an appropriate amount of force
used to press on the relatively hard inner member 26''. Upon
removal of the downward force by the user, the skin interface
member 20'' has sufficient flexibility/resiliency to spring back to
its initial position. The arrangement 10'' may further comprise a
slightly modified housing 16'' and/or attachment 22'' construction.
Thus, the housing 16'' may be provided with a shoulder 17'' upon
which a portion of the outer member 24'' is seated, thereby forming
an attachment 22'' between the skin interface member 20'' and the
housing 16''. The attachment 22'' may be fixed or movable. It
should be understood that the arrangement 10' may include any of
the features described in connection with any of the other
embodiments described herein, including the arrangements 10, 10' of
FIGS. 1-5.
[0074] Additional alternative constructions for arrangements and/or
skin interface members will now be described. However, it should be
understood that any of the skin interface member embodiments
described below can be utilized in conjunction with an arrangement
including any combination of features of the arrangements described
herein. The same reference numerals used above will also be used to
describe corresponding features in the description of the following
embodiments.
[0075] An alternative arrangement 100 constructed according to the
principles of the present invention is illustrated in FIGS. 7-8. As
illustrated therein, the arrangement 100 includes a modified skin
interface member 120. The skin interface member 120 can be formed
from any suitable material, such as an elastomer, silicone rubber,
or plastic. The skin interface member 120 comprises a first
projection 144 and a second projection 146. The first projection
144 is constructed and arranged to contact, and preferably form a
seal against, the cartridge 32, as illustrated in FIG. 8. The seal
formed against the cartridge 32 may be substantially vacuum-tight.
The second projection 146 is constructed and arranged to contact
the skin 12 of the user at the sampling site 14. As further
illustrated in FIG. 8, the first and second projections 144, 146
are constructed and arranged such that upon being pressed against
the skin 12, and optionally against the cartridge 32, the skin in
the vicinity of the sampling site 14 is pinched due to a converging
movement of the second projection 146. This convergence, or
pinching movement, aids in the perfusion of body fluid at the
sampling site 14, thereby improving the spontaneous production of a
body fluid when the skin penetration member 34 is driven into the
skin 12. Additional benefits of this embodiment include the
potential for the above described pinching as creating a
distraction to the user prior to insertion of the skin penetrating
member into the skin, thereby diminishing the overall pain
sensation of the body fluid sampling procedure.
[0076] An arrangement 200 formed according to a further alternative
arrangement of the present invention is illustrated in FIGS. 9-11.
The arrangement 200 includes a modified skin interface member 220
which is generally in the form of a tapered cylindrical member
having an opening 222 constructed and arranged to be contacted by
the skin 12 of the user. The skin interface member 220 comprises a
plurality of longitudinal slits 230 thereby forming a plurality of
longitudinal sections 235 which are separated from one another by a
plurality of gaps 240. As illustrated, for example, in FIGS. 10-11,
upon being pressed against the skin of the user the tapered
cylindrical member 220 moves in a longitudinally downward direction
within the first opening 18 of the housing 16. This longitudinally
downward movement forces a plurality of longitudinal sections
together in a converging manner so as to pinch the skin 12 of the
user together at the sampling site 14. This convergence, or
pinching movement, aids in the perfusion of body fluid at the
sampling site 14, thereby improving the spontaneous production of a
body fluid when the skin penetration member 34 is driven into the
skin 12. Additional benefits of this construction include its
simplicity of design and ease of manufacture, and the potential for
the above described pinching as creating a distraction to the user
prior to insertion of the skin penetrating member into the skin,
thereby diminishing the overall pain sensation of the body fluid
sampling procedure.
[0077] FIGS. 12-13 illustrate yet another alternative arrangement
300 formed according to the principles of the present invention. As
illustrated therein, the arrangement 300 includes a modified skin
interface member 320. The skin interface member 320 comprises a
plurality of concentric telescoping sections 330, including an
innermost section 332 defining and opening 18 therein. Upon
extension of the concentric telescoping sections 330, the innermost
section 332 eventually engages the surface of the skin 12 of the
user at the sampling site 14 in a manner which pinches the skin 12
in the vicinity of the sampling site 14. This convergence, or
pinching movement, aids in the perfusion of body fluid at the
sampling site 14, thereby improving the spontaneous production of a
body fluid when the skin penetration member 34 is driven into the
skin 12. Additional benefits of this construction include the
ability to store the skin interface member 320 with a low profile
when not in use, and the potential for the above described pinching
as creating a distraction to the user prior to insertion of the
skin penetrating member into the skin, thereby diminishing the
overall pain sensation of the body fluid sampling procedure.
[0078] Yet another arrangement 400 formed according to the
principles of the present invention is illustrated in FIGS. 14-16.
The arrangement 400 includes a modified skin interface member 420
disposed within an opening 18 of the housing 16. As illustrated
therein, the skin interface member 420 comprises a plurality of
rolling members 430 connected to pivots or axles 440 disposed in at
least both longitudinal ends of each rolling member 430. The pivots
or axles 440 are mounted in corresponding bores 442. As illustrated
in FIGS. 15-16, upon pressing against the skin 12 of the user a gap
445 defined between the rolling members 430 is caused to converge.
This can be accomplished by a number of different mechanisms. For
example, as illustrated in FIG. 14, the pivots or axles 440 can be
mounted within bores 442 which are angled toward one another.
Alternatively, the bores 442 can be substantially circular, and the
pivots or axles 440 can be offset with respect to the longitudinal
center axis of the rolling elements (FIGS. 15-16) so as to produce
the desired convergence or closing of the gap 445. This convergence
of the rolling elements 430 pinches the skin 12 of the user in the
vicinity of sampling site 14. Additional and benefits of this
embodiment include its simplicity and ease of manufacture, and the
potential for the above described pinching as creating a
distraction to the user prior to insertion of the skin penetrating
member into the skin, thereby diminishing the overall pain
sensation of the body fluid sampling procedure.
[0079] FIGS. 17-18 illustrates arrangements formed according to
other alternative embodiments of the present invention. As
illustrated therein, the arrangement 500 may include a housing 516
constructed in a manner which is similar to that previously
described herein. A modified skin interface member 520 is connected
to the housing 516 via a suitable attachment 522. According to this
embodiment, the skin interface member 520 is provided with a
suitable punch or cutting mechanism. Thus, according to the
non-limiting illustrated example, the skin interface member 520 is
provided with a relatively hard inner member 526 and a downwardly
projecting member 527 which including a formation or shape for
facilitating a cutting or punching action, such as sharpened lower
corner. The inner member 525 and the downwardly projecting member
527 may be integral with or removably connected to a relatively
softer flexible outer member 524, as described at length herein.
The arrangement 500 is useful when used in connection with a
frangible component. Thus, for example, the arrangement 500 may
optionally include a cartridge 532, which may have one or more of
the features described in connection with the cartridge 32 of
previous embodiments. The cartridge 532 may include a frangible
component 533. The frangible component 533 may take the form of a
seal, such as a thin layer of foil or similar material which
provides a sealed protected environment inside of the cartridge
532. As previously explained herein, the cartridge 532 may include
one or more skin penetration member(s) 534. Prior to, or
concurrently with, actuation of the skin penetration member 534 to
pierce the skin, the skin interface member 520 may be urged in the
direction of arrow D' thereby creating an opening in the frangible
component 533, as illustrated in the broken line portion of FIG.
17. The skin penetration member 534 is now free to travel through
the opening created by the skin interface member 520 in the
frangible component 533, and eventually into the surface of the
skin at the sampling site. According to a further optional aspect,
the downwardly projecting member 527 may also serve as a stop to
limit the depth of penetration of the skin penetration member 534,
as illustrated in FIG. 18. As illustrated therein, the skin
penetration member 534 may be provided with a suitable stopping
mechanism, such as the illustrated shoulder or collar 545.
Regardless of the specific form of the stopping member, it shall be
provided with a construction such that the stopping member 545
passes through the opening in the cartridge 532, but does not pass
through the opening presented by the bottom of the downwardly
projecting member 527. It should be understood that the skin
interface member 520 may be provided with a number of alternative
constructions, not specifically illustrated, which may provide the
above described punching or cutting or punching action.
[0080] FIGS. 19-21 illustrate embodiments whereby the size of the
opening of the inner member of the skin interface member can be
changed. The ability to change the size of the opening can provide
certain benefits and advantages For example, varying the opening
size can act as a catalyst by producing a squeezing of pulsing
pressure on the skin at the sampling site, and/or by controlling
the distance that the skin can stretch into the opening of the
inner member, thereby providing a depth control mechanism. Also,
the ability to close, or substantially close, the opening in the
skin interface member can provide the ability to act as a shutter
to shut out or limit exposure to the external environment and/or
ambient light. An arrangement 600 is illustrated in FIGS. 19-21 is
a non-limiting example of a specific construction for achieving the
above-noted objectives. As illustrated therein, the arrangement 600
includes a skin interface member 620 connected to a housing 16 by
any suitable manner, such as those previously described herein. The
skin interface member comprises a relatively soft and flexible
outer member 624 attached to a relatively hard inner member 626.
The inner member 626 is provided with a nominal opening having a
first diameter D1, and any suitable mechanism or construction for
changing the diameter of the opening to a second smaller diameter
D2. According to one nonlimiting example, the inner member 626 can
be formed, at least in part, from a shape memory material. Thus,
upon application of an appropriate stimulus, the material changes
shape in a manner such that the diameter of the opening is reduced.
Any suitable shape memory material can be utilized for this
purpose. For example, the inner member 626 may be formed from a
shape memory metal, such as Nitinol.TM.. Exemplary stimuli include
heat or electrical current. This reduction in diameter of the
opening of the inner member 626 can be utilized to produce one or
more of the following effects: squeezing of the skin at the
sampling site which is present within the nominal opening diameter
D1, reducing the amount of skin which can protrude down into the
opening of the inner member 626, thereby reducing the depth of
penetration of a skin penetration member at the sampling site; and
act as a shutter to shut out or limit exposure to the external
environment and/or ambient light (FIG. 21).
[0081] The stimulus or mechanism for effecting the change in
diameter can be initiated manually by a user, or automatically by
an associated device. For example, a user can select an appropriate
interface mechanism to initiate a single reduction in diameter, or
to initiate a cycle of changes in diameter between a larger
diameter opening (D1) and a smaller diameter opening (D2).
Alternatively, the stimulus or mechanism for effecting change in
diameter can be automatically initiated by an associated device
such as an arrangement or integrated meter as described herein. For
example, the device may be provided with one or more sensors, such
as those previously described herein, which are capable of sensing
contact of the device with the surface of the skin of a user,
and/or a pressure associated therewith. According to one
alternative embodiment, if the device fails to detect contact with
the skin, an appropriate stimulus, such as an electrical current,
can be automatically generated by the device and applied to a shape
memory material forming the inner member 626 thereby causing an
appropriate reduction in diameter. Thus, the device may
automatically enter a shutdown or standby mode wherein the diameter
(D2) of the opening of the inner member 626 is reduced to such an
extent that it entirely closes, or substantially closes, the
opening in the inner member 626, thereby shielding the inside of
the device from the external environment and/or ambient light
(e.g., FIG. 21). According to a further alternative embodiment, the
size or diameter of the opening in the inner member 626 can be
changed automatically based on the results of previous sample
collection efforts. For example, an arrangement can be provided
with sensors that detect the presence of a body fluid, such as
blood, as it enters the device. Sensors can also be provided that
measure or estimate the volume of body fluid, e.g., blood.
Conventional sensors can be used for this purpose. If the
arrangement senses a lack of body fluid, or an inadequate volume of
body fluid, a signal or stimulus can be sent to the inner member to
increase the diameter of the opening in the inner member 626. This
larger opening permits a deeper projection of the skin surface into
the larger opening thereby allowing a deeper penetration by a skin
penetration member, leading to a greater probability of obtaining
adequate sample size. Of course, the arrangement can operate in the
opposite manner; namely, upon sensing an oversupply of body fluid a
signal or stimulus can be sent to trigger a reduction in the
diameter of the opening in the inner member 626, thereby having the
opposite effect on penetration depth as an increase in the diameter
thereof.
[0082] As noted above, a number of alternative mechanisms are
contemplated for providing the desired change in diameter of the
inner member of the skin interface member 620. One such alternative
is illustrated in FIGS. 22-23. As illustrated therein, the inner
member 627' is in the form of a collapsible annular member formed
from relatively movable segments 627'a. A suitable actuator 629,
such as a cam mechanism/lever can be utilized to cause movement of
the segments 627'a relative to one another thereby causing the
above described reduction in diameter from D1 (FIGS. 22) to D2
(FIG. 23) by movement of the actuator 629 initiated manually by the
user or automatically by an associated device.
[0083] Another alternative mechanism is illustrated in FIG. 24. As
illustrated therein, the inner member 627'' can be provided with a
keyhole-like configuration. The keyhole-like configuration is
composed of a first portion 631 having a relatively large diameter
opening D1 and a second portion 633 having a relatively small
diameter opening D2. Thus, the desired reduction in diameter effect
is realized by placing the skin over the first portion 631, then
moving the skin in the direction of the second portion 633, or in
the direction of arrow DR.
[0084] FIGS. 25-26 illustrates an additional alternative embodiment
according to the principles of the present invention. According to
this aspect of the present invention, the skin interface member 20
can be attached or otherwise associated with a plate-like member
55. The plate-like member 55 is in turn removably mounted to or
associated with a housing 16 of a device or arrangement 10. The
skin interface member 20 can either be permanently affixed or
associated with the plate-like member 55, or can be removably
mounted thereto. The plate-like member 55 can be associated with a
housing 16 by any suitable mechanism, such as frictional interface,
detents, snaps, fasteners, adhesives, and the like. Preferably, the
plate-like member 55 is removable from the remaining portion of the
housing 16, so that a new or different plate-like member 55
containing a new or different skin interface member 20 can be used
to replace an existing plate-like member 55/interface member 20.
This arrangement is beneficial in that, after a period of use, the
skin interface member 20 and/or the plate 55 may become
contaminated with body fluids, such as blood. Therefore, it is
desirable to be able to exchange this portion of an arrangement 10
with a fresh skin interface member 20/plate-like member 55 unit. In
addition, this type of arrangement also improves flexibility in
terms of providing a mechanism for introducing different types of
skin interface members 20. For example, if a user is having
difficulty obtaining an adequate sample of blood using a certain
skin interface member 20 configuration, the user can select a
different interface member 20 which may provide for better blood
acquisition. It should be understood that the arrangement 10 can
have any suitable configuration and/or combination of features,
such as those previously described herein. Similarly, the skin
interface member 20 can be configured in any suitable manner.
Therefore, the skin interface member 20 may have any of the
configurations and/or features of the previously described
embodiments. The plate-like member 55 can be formed from any
suitable material, such as plastic or metal, and can be of any
suitable configuration or geometry.
[0085] An exemplary body fluid sampling method or technique which
may be used in conjunction with any of the above-described
arrangements, but is not necessarily limited thereto, is described
as follows.
[0086] A skin interface member is placed on the skin over a
sampling site located on a digit or at an alternate site. The skin
interface member has an opening therein which corresponds to the
sampling site. The skin interface member is provided with a
construction that aids or facilitates the perfusion of blood at the
sampling site, such as any of the skin interface member
constructions described herein, in order to improve the probability
of a spontaneous expression of blood upon wound creation. A
sequence of events is then initiated. The events can be initiated
manually, for example, by pressing a button or other triggering
mechanism. Alternatively, the events can be automatically
triggered, for example, through the use of one or more sensors
which determine when the skin interface member has been properly
positioned over a sampling site on the surface of the skin. A
catalyst is then optionally applied to the sampling site. The
catalyst can comprise one or more of heat, pressure, vacuum,
vibration, topical drugs, squeezing or combinations thereof. These
catalysts can be applied concurrently or sequentially relative to
one another. According to one embodiment, a catalyst in the form of
vacuum pressure is applied to the sampling site via a suitable
mechanism, such as a pump capable of creating vacuum pressure. The
catalyst can be applied for a set period of time, and then removed
or terminated. For example, the catalyst can be removed before,
during, or after penetration of the skin. Next, at least one skin
penetration member is actuated or driven into the surface of the
skin. The skin penetration member can take any suitable form, such
as a solid lancet or hollow needle (e.g., a microneedle). According
to one embodiment, the at least one skin penetration member
comprises a hollow needle having a first end configured to pierce
the surface of the skin, and an inner lumen. The at least one skin
penetration member can be actuated via any suitable mechanism, such
as a mechanical spring. According to one embodiment, body fluid is
transported away from the wound site via a suitable mechanism.
According to one embodiment, the body fluid, or blood, is
transported via the inner lumen of a hollow skin-penetration member
via capillary action, vacuum, or a combination of both. The body
fluid can be transported to an analyte quantification member of any
suitable construction. According to one embodiment, the analyte
quantification member comprises an assay pad which contains a
chemical reagent impregnated therein. Upon exposure to the body
fluid, a target analyte contained therein causes a chemical
reaction with the reagent producing a color change in the assay
pad. This color change can in turn be detected by a suitable
detection element. One such detection element comprises an optical
sensor.
[0087] Numbers expressing quantities of ingredients, constituents,
reaction conditions, and so forth used in this specification are to
be understood as being modified in all instances by the term
"about". Notwithstanding that the numerical ranges and parameters
setting forth, the broad scope of the subject matter presented
herein are approximations, the numerical values set forth are
indicated as precisely as possible. Any numerical value, however,
inherently contains certain errors necessarily resulting from the
standard deviation found in their respective measurement
techniques. None of the elements recited in the appended claims
should be interpreted as invoking 35 U.S.C. .sctn. 112, 6, unless
the term "means" is explicitly used.
[0088] Although the present invention has been described in
connection with preferred embodiments thereof, it will be
appreciated by those skilled in the art that additions, deletions,
modifications, and substitutions not specifically described may be
made without departing from the spirit and scope of the invention
as defined in the appended claims.
* * * * *