U.S. patent application number 11/105209 was filed with the patent office on 2006-05-11 for integrated spot monitoring device with fluid sensor.
Invention is credited to Christopher D. Wiegel, Daniel Wong.
Application Number | 20060100542 11/105209 |
Document ID | / |
Family ID | 34965983 |
Filed Date | 2006-05-11 |
United States Patent
Application |
20060100542 |
Kind Code |
A9 |
Wong; Daniel ; et
al. |
May 11, 2006 |
Integrated spot monitoring device with fluid sensor
Abstract
A bodily fluid sampling device is operable to breach the skin
surface and allow bodily fluid to emerge from the breach location.
The bodily fluid sampling device further evaluates the amount of
bodily fluid emerged from breach location and determines whether
the amount is sufficient or insufficient for a particular purpose,
such as sampling and testing. The determination is accomplished
automatically without moving the device. The user may also
intervene to perform a variety of tasks following the determination
of the amount of bodily fluid.
Inventors: |
Wong; Daniel; (Sunnyvale,
CA) ; Wiegel; Christopher D.; (San Jose, CA) |
Correspondence
Address: |
WOODARD, EMHARDT, MORIARTY, MCNETT & HENRY LLP
111 MONUMENT CIRCLE, SUITE 3700
INDIANAPOLIS
IN
46204-5137
US
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20050234368 A1 |
October 20, 2005 |
|
|
Family ID: |
34965983 |
Appl. No.: |
11/105209 |
Filed: |
April 13, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60562377 |
Apr 15, 2004 |
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Current U.S.
Class: |
600/583 ;
600/573; 600/584 |
Current CPC
Class: |
A61B 5/150702 20130101;
A61B 5/150503 20130101; A61B 5/150717 20130101; A61B 5/15192
20130101; A61B 5/150022 20130101; A61B 5/14532 20130101; A61B
5/150358 20130101; A61B 5/150053 20130101; A61B 5/150916 20130101;
A61B 5/15117 20130101; A61B 5/150442 20130101; A61B 5/150213
20130101; A61B 5/15107 20130101; A61B 5/150412 20130101; A61B
5/15125 20130101; A61B 5/1519 20130101; A61B 5/1513 20130101 |
Class at
Publication: |
600/583 ;
600/573; 600/584 |
International
Class: |
A61B 5/00 20060101
A61B005/00; B65D 81/00 20060101 B65D081/00 |
Claims
1. A body fluid sampling device, comprising: a lancing device
configured to create an incision in a surface of tissue; a fluid
detector configured to detect sufficiency of body fluid bled from
the incision while on the surface of the tissue; an expression
device operatively coupled to the fluid detector; the fluid
detector being configured to have the expression device
automatically express the body fluid from the incision upon
detecting that the body fluid on the surface of the tissue is
insufficient for analysis; and an analysis device configured to
analyze the body fluid once the fluid detector detects that the
body fluid on the surface of the tissue is sufficient for
analysis.
2. The body fluid sampling device of claim 1, further comprising:
means for creating the incision, wherein the means for creating the
incision includes the lancing device; means for detecting the
sufficiency of the body fluid bled from the incision while on the
surface of the tissue, wherein the means for detecting the
sufficiency of the body fluid includes the fluid detector; means
for expressing the body fluid from the incision, wherein the means
for expressing the body fluid includes the expression device; and
means for analyzing the body fluid, wherein the means for analyzing
the body fluid includes the analysis device.
3. The body fluid sampling device of claim 1, wherein: the lancing
device includes a lancet coupled to a firing mechanism; and the
fluid detector includes the lancet, the lancet including an
electrically conductive material for detecting the body fluid upon
the body fluid contacting the lancet.
4. The body fluid sampling device of claim 1, further comprising: a
housing in which the fluid detector is disposed, the housing
defining a cavity with an opening where the incision is created;
and wherein the fluid detector includes an ultrasonic detector
configured to detect a change in resonance of the cavity in the
housing as the body fluid from the incision fills the cavity.
5. The body fluid sampling device of claim 1, wherein the fluid
detector includes a position sensing detector configured to detect
height of the body fluid from the surface of the tissue by
triangulating reflected light from the body fluid.
6. The body fluid sampling device of claim 1, wherein the fluid
detector includes a thermal sensor.
7. The body fluid sampling device of claim 1, wherein the fluid
detector includes a sensor disposed proximal the tissue to detect
the sufficiency of the body fluid by measuring capacitance changes
between the tissue and the sensor caused by bleeding of the body
fluid from the incision.
8. The body fluid sampling device of claim 7, wherein: the
expression device includes one or more electrodes to electrically
stimulate the tissue; and the sensor is configured to detect
sufficiency of the body fluid based electrical signals from the
electrodes.
9. The body fluid sampling device of claim 1, further comprising: a
housing defining a sampling chamber with an opening through which
the lancing device creates the incision, the housing having a skin
contacting portion around the opening that contacts the tissue
during creation of the incision; and wherein the expression device
is configured to express the body fluid without requiring removal
of the skin contacting portion of the housing from the tissue.
10. The body fluid sampling device of claim 1, further comprising:
a controller operatively coupled to the lancing device and the
firing mechanism; and an output device operatively coupled to the
controller, wherein the output device is configured to positively
indicate insufficiency of the body fluid when the fluid detector
detects the insufficiency of the body fluid.
11. The body fluid sampling device of claim 1, wherein: the lancing
device includes a lancet; the analysis device includes a test strip
coupled to the lancet; the test strip and the lancet form an
integrated lancing test strip; and the fluid detector includes one
or more sensors disposed on the integrated lancing test strip.
12. The body fluid sampling device of claim 11, wherein: the test
strip defines a capillary channel with a capillary channel opening
for drawing the body fluid; and the sensors are disposed proximal
the capillary channel opening for locating the capillary channel
opening during drawing of the body fluid.
13. The body fluid sampling device of claim 1, wherein the analysis
device includes a test strip with a capillary channel for drawing
the body fluid and an actuator coupled to the test strip for
positioning the capillary channel to collect the body fluid when
the fluid detector detects a sufficient amount of the body fluid on
the surface of the tissue.
14. A body fluid sampling device, comprising: a test strip
including a capillary channel for drawing body fluid from a tissue
and an analysis portion located along the capillary channel for
analyzing the body fluid; and wherein the test strip has a fluid
detector to sense sufficiency of the body fluid on the tissue
before the body fluid is drawn into the capillary channel.
15. The body fluid sampling device of claim 14, further comprising:
a lancet coupled to the test strip for creating an incision in the
tissue.
16. The body fluid sampling device of claim 15, wherein: the lancet
is fixed to the test strip; and the capillary channel has an
opening that is positioned at an oblique angle relative to the
lancet.
17. The body fluid sampling device of claim 15, wherein the lancet
is coupled to the test strip in a slidable manner to allow
extension of the lancet from the test strip.
18. The body fluid sampling device of claim 15, wherein the fluid
detector includes the lancet, the lancet being configured to form a
closed electrical circuit upon the body fluid contacting the
lancet.
19. The body fluid sampling device of claim 14, wherein the fluid
detector includes at least one sensor configured to measure changes
in capacitance between the tissue and the sensor as the body fluid
bleeds from an incision.
20. The body fluid sampling device of claim 14, wherein: the
capillary channel has an opening for receiving the body fluid; and
the fluid detector is disposed proximal to the opening to sense
distance between the opening and the tissue.
21. The body fluid sampling device of claim 14, further comprising:
means for analyzing the body fluid, wherein the means for analyzing
the body fluid includes the test strip; means for sensing
sufficiency of the body fluid on the tissue, wherein means for
sensing sufficiency of the body fluid on the tissue includes the
fluid detector; and means for creating an incision in the
tissue.
22. A method, comprising: placing a sampling device against tissue;
creating an incision in the tissue with the sampling device;
detecting with the sampling device that body fluid bled from the
incision on the tissue is insufficient for analysis; and expressing
the body fluid from the incision automatically with the sampling
device in response to said detecting while the sampling device
remains against the tissue.
23. The method of claim 22, wherein said detecting includes
monitoring rate of bleeding of the body fluid from the
incision.
24. The method of claim 22, wherein said detecting includes
monitoring amount of body fluid on the tissue.
25. The method of claim 22, further comprising: determining with
the sampling device that the body fluid on the tissue is sufficient
for analysis after said expressing; and analyzing the body fluid
with the sampling device after said determining.
26. The method of claim 22, wherein said expressing includes
electrically stimulating the tissue with electrodes of the sampling
device.
27. The method of claim 22, wherein: the sampling device includes
an integrated lancing test strip that includes a lancet coupled to
a test strip and a fluid detector; said creating the incision
includes forming the incision with the lancet; and said detecting
includes monitoring the body fluid on the tissue with the fluid
detector of the integrated lancing test strip.
28. The method of claim 22, wherein: the sampling device includes a
housing with a cavity and a fluid detector configured to generate
ultrasound in the cavity; and said detecting includes monitoring
resonance of the ultrasound in the cavity of the housing.
29. The method claim 22, wherein: the sampling device includes one
or more sensors; and said detecting includes monitoring capacitance
between the sensors and the tissue.
30. The method of claim 22, further comprising: wherein the
sampling device includes an output device; and activating the
output device to indicate insufficiency of the body fluid upon said
detecting.
Description
REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S.
Provisional Patent Application No. 60/562,377, filed Apr. 15, 2004,
which is hereby incorporated by reference in its entirety.
BACKGROUND
[0002] The present invention generally relates to bodily fluid
sampling devices and more specifically, but not exclusively,
concerns a bodily fluid sampling device configured to evaluate the
amount of bodily fluid emerged from a rupture on the surface of
skin and determine whether the amount is sufficient or insufficient
for testing without the need to move the device.
[0003] The acquisition and testing of bodily fluids is useful for
many purposes, and continues to grow in importance for use in
medical diagnosis and treatment, and in other diverse applications.
In the medical field, it is desirable for lay operators to perform
tests routinely, quickly and reproducibly outside of a laboratory
setting, with rapid results and a readout of the resulting test
information. Testing can be performed on various bodily fluids, and
for certain applications is particularly related to the testing of
blood and/or interstitial fluid. Such fluids can be tested for a
variety of characteristics of the fluid, or analytes contained in
the fluid, in order to identify a medical condition, determine
therapeutic responses, assess the progress of treatment, and the
like. The fingertip is frequently used as a fluid source because it
is highly vascularized and therefore produces a good quantity of
blood. However, the fingertip also has a large concentration of
nerve endings, and lancing the fingertip can therefore be painful.
Alternate sampling sites, such as the palm of the hand, forearm,
earlobe and the like, may be useful for sampling, and are less
painful. However, they also produce less blood when lanced, thereby
increasing the likelihood of that the collected blood sample will
be insufficient for accurate test results. For example, if the
fluid sample is drawn from the skin onto a test strip prior to the
emergence of a sufficient quantity on the skin, the test strip has
to be discarded because the test strip is unable to accurately
analyze the fluid. Typically, the user then has to lance another
site in order to attempt to obtain another sample of fluid. As
should be appreciated, this can make monitoring unnecessarily
painful as well as expensive.
[0004] Sampling devices have been proposed to detect body fluid on
the surface of the skin, but these devices still have a number of
drawbacks that have prevented the implementation of this fluid
detection feature into a successful commercial product. For
instance, although these devices are able to alert the user when a
sufficient amount of fluid is present on the skin, these sampling
devices do not take any actions to automatically increase the
amount of fluid when the amount is insufficient. Further, these
sampling devices only alert the user when a sufficient amount of
fluid is present, and fail to alert the user of fluid
insufficiency. By failing to positively alert the user of the fluid
insufficiency can make the user question whether the sampling
system is working properly. As a result, the user may prematurely
remove the sampling device to check its progress before a
sufficient amount of fluid can bleed from the incision. Once the
device is removed from the skin, automatic fluid collection is
practically impossible due to the misalignment created between the
incision and the sampling device when the user places the device
again over the incision site. Thus, there remains a need for
improvement in this field.
SUMMARY
[0005] One embodiment concerns a bodily fluid sampling device that
includes integrated spot monitoring of emerged bodily fluid. A
monitoring, or detecting member, determines the amount of bodily
fluid emerged, the rate of emergence of bodily fluid, or both from
an opening in the skin's surface. A controller evaluates whether
the emerged fluid volume is sufficient for a desired purpose, such
as by way of nonlimiting example, testing for particular
properties. If the emerged fluid's volume is sufficient, a
collection device collects the fluid. If the emerged fluid's volume
is insufficient, the collection of the fluid will be delayed until
sufficient fluid has emerged.
[0006] Another aspect concerns a technique for acquiring a bodily
fluid sample with an integrated sampling device. The integrated
sampling device includes a skin-contacting member for supporting
the device against the skin and a means for rupturing the skin
surface. Further, the device includes a means for expressing fluid
from the rupture location without removing the skin-contacting
member from the skin and a means for collecting the fluid. The
means for collecting the fluid includes a collection device with a
dosing opening. The skin-contacting member is placed against the
skin and, without moving the skin-contacting member from the skin,
the skin is lanced to form an incision. Bodily fluid is allowed to
move out of the incision site and the amount of fluid is determined
without moving the skin-contacting member from the skin. If the
fluid amount is determined as insufficient, additional fluid is
expressed from the incision without moving the skin-contacting
member from the skin. The fluid is then collected from the incision
site into the dosing opening.
[0007] In a further aspect, the skin in the area of the incision is
penetrated to enhance the expression of fluid upon forming the
incision. The means by which the additional fluid is expressed may
be different from the means by which the fluid is expressed prior
to determining its amount.
[0008] It is also contemplated that fluid from the incision can be
expressed after the skin is lanced and prior to determining the
amount of fluid.
[0009] It is envisioned that the fluid may be expressed one or more
of the following manners: via electrical stimulation, via physical
stimulation, mechanically, thermally or via electromagnetic
stimulation.
[0010] The determination of the amount of fluid may be performed by
any one of the following manners: visually, electrically, sonically
or electromagnetic detection.
[0011] It is also envisioned the determination of whether there is
a sufficient amount of fluid at the rupture site can occur after
the additional fluid is expressed and before the additional fluid
is collected.
[0012] It is also contemplated that the device can signal the user
after determining that the fluid sample is insufficient. The
signaling can also include identifying the need to perform
expression of additional fluid.
[0013] The skin can be relanced after the device determines that
the amount is insufficient and before additional fluid is
expressed.
[0014] The device can further include a means for testing the fluid
for an analyte, which tests the fluid for an analyte after the
fluid is collected from the rupture site.
[0015] Another aspect concerns a technique for acquiring a bodily
fluid sample. An integrated sampling device includes a
skin-contacting member for supporting the device against the skin
and a means for forming an incision in the skin. The device
includes a means for expressing fluid from the incision formed in
the skin onto the skin's surface without removing the
skin-contacting member from the skin and a means for collecting
fluid from the skin's surface. The means for collecting fluid
includes a collection device with at least a first dosing opening.
The skin-contacting member is placed against the skin, and without
moving the member from the skin, the skin is lanced to form an
incision, and movement of fluid onto the skin's surface is allowed.
Without moving the skin-contacting member from the skin, the device
determines that the amount of fluid is insufficient. The sampling
device is repositioned, and the steps of placing the
skin-contacting member against the skin, lancing the skin without
moving the member from the skin, and allowing the movement of fluid
onto the skin's surface are repeated. The device can also determine
that the amount of fluid is sufficient, and the fluid is then
collect from the skin's surface into the dosing opening.
[0016] A further aspect concerns a technique for acquiring a fluid
sample. An integrated sampling device includes a skin-contacting
member for supporting the device against the skin and a means for
forming an incision in the skin. The device further includes a
means for expressing fluid from the incision formed in the skin
without removing the skin-contacting member from the skin and a
means for collecting fluid from the incision site that includes a
collection device with at least a first dosing opening. The
skin-contacting member is placed against the skin and, without
moving the member from the skin, the skin is lanced to form an
incision, and the movement of fluid out of the incision site is
allowed. Without moving the skin-contacting member from the skin,
the device determines that the amount of fluid is sufficient, and
the fluid is collected from the incision site into the first dosing
opening.
[0017] Still yet another aspect concerns a technique for acquiring
a fluid sample. An integrated sampling device is provided within a
housing. The integrated sampling device includes a skin-contacting
member for supporting the device against the skin and a means for
breaching the skin surface. The device further includes a means for
expressing fluid from the breach formed in the skin without
removing the member from the skin and a means for collecting fluid
from the location that includes a collection device with at least a
first dosing opening. The skin-contacting member is placed against
the skin and, without moving the member from the skin, the skin is
lanced to form an incision. The movement of fluid out of the
incision location is allowed. Without moving the member from the
skin, the device determines if there is a predetermined amount of
fluid at the breach location. Based on the outcome of this
determination, one of the following two procedures is performed:
(1) prior to collecting fluid, the device determines that the
amount of fluid is sufficient and then fluid is collected from the
breach location into the dosing opening; or (2) the device
determines that the amount of fluid is insufficient and either (a)
additional fluid is expressed from the breach location without
moving the member from the skin and thereafter collecting fluid, or
(b) the sampling device is repositioned and the steps of placing
the member against the skin, breaching the skin surface, and
determining whether there is a predetermined amount of fluid at the
new location, and then performing one of the two procedures are
repeated. The additional fluid can be collected through the dosing
opening.
[0018] Optionally, step (2)(b) of the above-mentioned technique can
include determining that the amount of fluid is insufficient.
[0019] Also, the determination of whether there is a predetermined
amount of fluid on the skin's surface can occur prior to collecting
any of the fluid.
[0020] At least a portion of the fluid produced by lancing the skin
can be collected through the dosing opening prior to determining if
there is a predetermined amount of fluid on the skin's surface.
[0021] The integrated sampling device can include a second dosing
opening, and the additional fluid can be collected through the
second dosing opening.
[0022] It is contemplated that step (2) of the above-mentioned
technique can include expressing additional fluid from the
incision, and without removing the member from the skin, again
determining if there is a predetermined amount of fluid at the
incision location.
[0023] Another aspect concerns an integrated sampling device. The
integrated sampling device includes a breaching member for
breaching the surface of the skin to cause bodily fluid to emerge.
The device further includes a sampling device for sampling the
emerged bodily fluid and a size determining member for determining
the size of the fluid emerged from the ruptured skin prior to the
emerged fluid being sampled by the sampling device.
[0024] A further aspect concerns an integrated sampling device for
bodily fluid that includes a rupturing member for rupturing the
surface of the skin to cause bodily fluid to emerge. The device
further includes a means for automatically determining whether the
emerged bodily fluid is sufficiently sized for sampling and a
sampling device for sampling the emerged bodily fluid if the
emerged bodily fluid is sufficiently sized. The integrated sampling
device can further include a means for automatically expressing
additional fluid if the emerged bodily fluid is insufficiently
sized.
[0025] Still yet another aspect concerns a technique for acquiring
a fluid sample that includes providing an integrated sampling
device. The skin is lanced to form an incision, and movement of
fluid onto the skin surface is allowed. The amount of fluid on the
skin surface is determined, and, based on the determination of the
amount of fluid, proceeding with either: (1) determining that the
amount of fluid is insufficient and either (a) expressing
additional fluid and repeating the determination, or (b) repeating
the determination; or (2) determining that the amount of fluid is
sufficient and collecting the fluid. The integrated sampling device
can include a means for forming an incision in the skin, a means
for expressing fluid from the incision onto the skin surface, and a
means for collecting fluid from the incision location.
[0026] Another aspect concerns a body fluid sampling device that
includes a lancing device configured to create an incision in a
surface of tissue. A fluid detector is configured to detect
sufficiency of body fluid bled from the incision while on the
surface of the tissue, and an expression device is operatively
coupled to the fluid detector. The fluid detector is configured to
have the expression device automatically express the body fluid
from the incision upon detecting that the body fluid on the surface
of the tissue is insufficient for analysis. An analysis device is
configured to analyze the body fluid once the fluid detector
detects that the body fluid on the surface of the tissue is
sufficient for analysis.
[0027] A further aspect relates to a body fluid sampling device
that includes a test strip.
[0028] The test strip includes a capillary channel for drawing body
fluid from a tissue and an analysis portion located along the
capillary channel for analyzing the body fluid. The test strip has
a fluid detector to sense sufficiency of the body fluid on the
tissue before the body fluid is drawn into the capillary
channel.
[0029] Another aspect concerns a method in which a sampling device
is placed against tissue. An incision is created in the tissue with
the sampling device, and the sampling device detects that body
fluid bled from the incision on the tissue is insufficient for
analysis, and in response, the body fluid is expressed from the
incision automatically with the sampling device while the sampling
device remains against the tissue.
[0030] Further forms, objects, features, aspects, benefits,
advantages, and embodiments of the present invention will become
apparent from a detailed description and drawings provided
herewith.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a cross-sectional view of a bodily fluid sampling
device according to one embodiment.
[0032] FIG. 2 is a cross-sectional view of the FIG. 1 device during
lancing.
[0033] FIG. 3 is a cross-sectional view of the FIG. 1 device with
emerged fluid at the lancing site.
[0034] FIG. 4 is a cross-sectional view of the FIG. 1 device during
sampling.
[0035] FIG. 5 shows a flow diagram that illustrates a technique for
collecting fluid according to one embodiment.
[0036] FIG. 6 is an exploded view of an integrated lancing test
strip according to one embodiment.
[0037] FIG. 7 is a top perspective view of the FIG. 6 integrated
lancing test strip with its lancet in an extended position.
[0038] FIG. 8 is a bottom perspective view of the FIG. 6 integrated
lancing test strip with the lancet in a retracted position.
[0039] FIG. 9 is a partial cross-sectional view of the FIG. 6
device after creating an incision.
[0040] FIG. 10 is a top view of an integrated lancing test strip
according to a further embodiment.
[0041] FIG. 11 shows the FIG. 10 device lancing the skin to form an
incision.
[0042] FIG. 12 shows the FIG. 10 device as the lancet is retracted
from the incision.
[0043] FIG. 13 shows the FIG. 10 device positioned to sample body
fluid from the incision.
DESCRIPTION OF SELECTED EMBODIMENTS
[0044] For the purposes of promoting an understanding of the
principles of the invention, reference will now be made to the
embodiments illustrated in the drawings and specific language will
be used to describe the same. It will nevertheless be understood
that no limitation of the scope of the invention is thereby
intended, such alterations and further modifications in the
illustrated device, and such further applications of the principles
of the invention as illustrated therein being contemplated as would
normally occur to one skilled in the art to which the invention
relates. One embodiment of the invention is shown in great detail,
although it will be apparent to those skilled in the relevant art
that some features that are not relevant to the present invention
may not be shown for the sake of clarity.
[0045] In one embodiment, a bodily fluid sampling device is
operable to detect the amount of emerged bodily fluid available for
sampling from an incision in the surface of skin or other tissue.
In another embodiment, the bodily fluid sampling device is operable
to detect the rate of emergence of bodily fluid from the incision.
While still in other embodiments, the bodily fluid sampling device
detects both the amount and the rate of emergence of bodily fluid
from the incision. The bodily fluid sampling devices further
determine whether the amount of fluid is sufficient, or
insufficient, for sampling. After the amount, or rate of emergence,
of bodily fluid is determined, the device can automatically
intervene to perform a variety of tasks, such as expressing the
fluid, or in addition, the user can intervene, if so desired. For
instance, when an insufficient amount of fluid is present on the
skin, the device can continue to automatically express additional
fluid, either actively or passively, or sample the fluid regardless
of whether it is insufficient.
[0046] A bodily fluid sampling device 100 according to one
embodiment, among many, is illustrated in FIGS. 1, 2, 3 and 4. The
sampling device 100 includes a housing 101 with a skin-contacting
or standoff member 102, and the housing 101 defines an internal
cavity or collection chamber 104. As shown in FIG. 1, the
skin-contacting member 102 is configured to be placed against skin
or tissue 106. It should be recognized that the sampling device 100
can collect fluid from other types of tissues, in addition to skin,
and can collect fluid from human as well as animal subjects. In the
collection chamber 104, the sampling device 100 includes an
incision forming device 110 for rupturing the skin 106. The
incision forming device 110 in the illustrated embodiment includes
a lancet, but it should be appreciated that other types of devices
for rupturing the skin 106 can be used. For instance, the incision
forming device 110 in other embodiments can include a blade, a
laser, a pneumatic type lancet and/or a hydraulic type lancet, to
name a few. The lancet 110 can be made of various materials capable
of rupturing the skin surface 106, for example, surgical stainless
steel, plastics, fiber composites, and/or ceramics. In the
illustrated embodiment, a firing mechanism or lancet actuator 115
is coupled to the lancet 110 for firing the lancet 110 to form an
incision in the skin 106. The actuator 115 in one embodiment
includes an electric motor, and in another embodiment, the actuator
115 includes one or more springs for firing and retracting the
lancet 110. However, it should be appreciated that the actuator 115
can include other types of firing devices, such as a pneumatic or
hydraulic motor.
[0047] Referring to FIG. 1, the integrated sampling device 100
further includes a detector 120 for determining the amount of body
fluid that emerges from an incision. In alternate embodiments, the
detector 120 determines the rate of emergence of bodily fluid. It
is contemplated that the detector 120 in other embodiments can be
configured to detect other properties as well. In one embodiment,
the detector 120 detects the fluid sample ultrasonically. When
detecting fluid ultrasonically, the detector 120 includes a
transducer that generates an ultrasonic field within the collection
chamber 104 and a receiver that receives reflected ultrasound
waves. The detector 120 detects the fluid sample based on the
change in the resonance of the ultrasonic field in the collection
chamber 104 as fluid fills the cavity 104. As should be
appreciated, the detector 120 in other embodiments can detect fluid
in other manners. It is contemplated that the body fluid in other
embodiments can be detected via a vision system, electrically,
and/or through thermal imaging, for example. For instance, the
detector 120 in another embodiment includes a position sensing
detector (PSD), which can be a one or two axis type PSD that
triangulates the location of the drop of body fluid. In another
example embodiment, the detector 120 includes a charge couple
device (CCD) that triangulates the location of the body fluid drop
and/or measures the size and/or shape of the drop. Although the
detector 120 is depicted as a single unit, in other embodiments the
detector 120 includes multiple elements, such as an array of
sensors.
[0048] Also included in the sampling device 100 is a collection
device 130 with a dosing opening 132 for collecting a sample of the
body fluid. In the illustrated embodiment, the collection device
130 includes a capillary tube, but it is envisioned that other
types of collection devices can be used. The collection device 130
can include a test strip and/or wicking material, for example. A
collection device actuator 135 is used to place the collection
device 130 in fluid communication with the bodily fluid, although
other embodiments do need the collection device actuator 135, such
as when the collection device 130 is fixed so that the dosing
opening 132 is already positioned over the incision site. Due to
variations in the properties of skin, such as elasticity, the
distance that the collection device 130 must travel to collect a
fluid sample can vary. In one embodiment, the detector 120 acts as
a range finder to ultrasonically determine the location of the
surface of the skin 106 and/or the body fluid. Based on the
determined location, the collection actuator device 135 can adjust
how far the collection device 130 extends toward the skin.
[0049] A testing device 140 for testing the bodily fluid sample for
particular properties is fluidly coupled to the collection device
130 via the collection device actuator 135 to receive the body
fluid from the collection device 130. In one embodiment, the
testing device 140 is in the form of an electrochemical sensor that
tests the fluid based on the electrochemical properties of the
fluid. As should be appreciated that testing device 140 can test
the body fluid sample in other manners. For example, the testing
device 140 can test the fluid sample in other manners, such as
chemically and/or optically, to name a few. As shown in FIG. 1, the
sampling device 100 includes an expression device 145 that is
positioned proximal to the skin 106 for expressing body fluid from
an incision. Expression device 145 can use a variety of techniques
to express additional bodily fluid, such as by way of nonlimiting
example, thermal heating, electrical stimulation, vacuum,
additional lancing, vibration, and/or kneading. In one embodiment,
the expression device 145 is used to mechanically express fluid
from an incision, and in particular, the expression device 145
includes a ring shaped member that is pressed against the skin 106
to express fluid. It is envisioned that the expression device can
express fluid in other manners. For example, in another embodiment,
the expression device 145 expresses fluid by electrically
stimulating the skin with an array of electrodes. In other forms,
the expression device 145 can express body fluid thermally, via a
vacuum and/or by spraying an anticoagulant at the incision site,
for instance. Although the lancet 110, the collection device 130,
the testing device 140 and the detector 120 in the illustrated
embodiment are shown as separate components, it should be
appreciated that two or more of these components can be integrated
into a single unit. As an example, the lancet 110, the collection
device 130 and the testing device 140 can be incorporated into an
integrated lancing test strip of the type disclosed in U.S. patent
application No. 10/330,724, filed Dec. 27, 2002, which is hereby
incorporated by reference in its entirety. Likewise, it is
envisioned that other components of the sampling device 100 can be
integrated together.
[0050] The sampling device 100 further includes a controller 150 to
coordinate the operation of the lancet actuator 115, the detector
120, the collection device actuator 135, the testing device 140,
and the expression device 145. As depicted, the controller 150 is
operatively coupled directly to three components, the lancet
actuator 115, the detector 120 and the testing member 140, and
indirectly coupled to two other components, the expression device
145 and the collection device actuator 135, by communication
pathways 155. It nevertheless should be appreciated that the
components in the sampling device 100 can be coupled to the
controller 150 in other manners, such as via a wireless connection,
and/or in a different configuration. For example, the expression
device 145 in other embodiments can be operatively coupled to the
controller 150 in a direct manner. As should be appreciated the
controller 150 can communicate with the components of the sampling
device 100 via a number of manners, such as through a serial or
parallel interface. As shown in FIG. 1, an input/output (I/O)
device 157 is mounted on the housing 101 and is operatively coupled
to the controller 150. Via the I/O device 157, the controller 150
is able to display messages to the user and receive commands from
the user. For example, the user can actuate the I/O device 157 to
fire the lancet 110, and once the body fluid sample from the
incision is analyzed, the I/O device 157 can display the results to
the user. It nevertheless should be appreciated that the I/O device
157 can perform other types of functions. In one embodiment, the
I/O device 157 includes a display and one or more entry buttons.
Although the I/O device 157 is illustrated as an integrated unit,
it should be appreciated that the input and output components of
the I/O device 157 can be configured as separate components. It is
contemplated that sampling device 100 in other embodiments may have
only an input device or an output device. The I/O device 157 can
include any type of input and/or output device as would occur to
those skilled in the art. For instance, the I/O device 157 can
incorporate keypads, microphones, speakers, displays, lights as
well as other types of input and/or output devices.
[0051] A technique, according to one embodiment, for collecting
body fluid 160 from an incision 165 will now be described with
reference to flowchart 200 in FIG. 5. In stage 202, the sampling
device 100 is placed in contact with the skin 106, as is depicted
in FIG. 1. Once placed against the skin 106, the expression device
145 in one embodiment is used to prime the incision site before the
incision is formed by drawing body fluid 160 within the skin 106
towards the incision site. For example, the expression device 145
can be pressed against the skin 106 in order to prime the incision
site. In another form, the expression device 145 electrically
stimulates the skin 104 to draw body fluid to the incision site,
and in still yet another form, the expression device 145 heats the
skin 106 to prime the incision site. It should be appreciated that
the incision site can be primed in other manners, however. For
example, a vacuum can be used to prime the site. Further, it is
envisioned that in other embodiments a separate device can be used
to prime the incision site before the sampling device 100 is placed
against the skin 106 in stage 202. In still yet another embodiment,
the incision site is not primed before an incision is formed.
[0052] Referring to FIG. 2, while remaining in contact with the
skin 106, the sampling device 100 in stage 204 fires the lancet 110
to form the incision 165 in the skin 106. The lancet 110 can be
fired automatically by the sampling device 100 or manually by the
user. To fire manually, the user actuates the I/O device 157, which
sends a firing signal to the controller 150. To automatically fire,
the detector 120 in one embodiment detects the presence of the skin
106, and upon detecting the skin 106 (or after a predetermined
delay), the detector 120 sends a firing signal to the controller
150. In one form where an ultrasonic type detector is used, the
detector 120 sends the firing signal to the controller 150 when the
detector 120 senses an ultrasonic resonance that indicates
placement of the device 100 against the skin 106. In other
embodiments, the lancet actuator 115 is activated by mechanisms
other than the controller 150, such as through a mechanical linkage
when sufficient pressure is generated between the skin-contacting
member 102 and the skin 106. After receiving the appropriate signal
from the controller 150, the lancet actuator 115 moves the lancet
110 to rupture the skin 106, and once the incision 165 is formed,
the lancet 110 is retracted. It should be understood that the
lancet 110 can be fired in other manners. As mentioned before, the
incision can be formed in stage 204 with other types of devices
besides that lancet 110, such as with a laser. During formation of
the incision 165, the expression device 145 can continue to prime
the incision site so that the body fluid rapidly discharges from
the incision 165, once formed. Alternatively, the priming can cease
before the incision 165 is formed.
[0053] After rupturing the skin 106, body fluid 160 tends to
naturally emerge from the incision 165, as is illustrated in FIG.
3. If needed, discharge of the body fluid 160 from the incision 165
can be enhanced with the expression device 145. For example, the
expression device 145 in one embodiment is pressed against the skin
106 to force additional body fluid 160 from the incision 165. In
another embodiment, the body fluid 160 is allowed to naturally
bleed from the incision 165 without the assistance of the
expression device 145. Without removing the device 100 from the
skin 106, the detector 120 in stage 206 determines whether an
adequate amount of body fluid 160 has emerged from the incision
165. The adequacy or sufficiency of the amount of body fluid 160 is
based on the amount of body fluid 160 required to sample and
analyze with the testing device 140 to assure generally accurate
results. It should be understood the fluid sufficiency amount can
as well incorporate other factors, such as a safety margin. For
instance, if a 1 .mu.L or greater sample size is required for
accurate results, then a 0.5 .mu.L safety margin can be added to
account for fluid loss during sampling, thereby resulting in a 1.5
.mu.L fluid sufficiency amount. As testing technology improves, the
amount of fluid required can in turn be less than 1 .mu.L. In
certain embodiments, the detector 120 determines whether the amount
of emerged body fluid 160 exceeds a minimum threshold. While in
other embodiments, the detector 120 periodically (or continuously)
measures the amount of emerged body fluid 160 and relays this
information to the controller 150, which makes a determination
whether the emerged body fluid 160 is accumulating at a sufficient
rate or exceeds a predetermined threshold. In still other
embodiments, the detector 120 directly measures the rate at which
the emerged body fluid 160 is accumulating. It is contemplated that
the detector 120 in other embodiment can detect the sufficiency of
the fluid sample in a binary fashion, that is, whether or not a
sufficient fluid level has been reached. While the detector 120 is
detecting the sufficiency of the fluid sample, the I/O device 157
in one embodiment can notify the user of whether or not a
sufficient sample of body fluid 160 has collected on the skin 106.
For example, in one embodiment, the I/O device 157 includes an
indicator light emitting diode (LED) that illuminates only when a
sufficient amount of fluid 160 is collected, and in another
embodiment, the LED darkens when a sufficient amount of fluid is
collected. In still yet further forms, the LED displays a "wait",
"fluid insufficient" or other types of messages to positively
indicate that the body fluid 160 bled thus far is insufficient for
testing, and the LED can display a "testing", "fluid sufficient" or
other similar messages to affirmatively indicate that the detected
body fluid 160 is enough for testing purposes. Positively
indicating fluid insufficiency reduces the chance that the user
will prematurely remove the device 100 from the skin 106, which
would make automatic fluid sampling practically impossible. It
should be understood that the I/O device 157 can indicate body
fluid sufficiency in other manners, or not at all.
[0054] As noted before, various techniques may be utilized to
determine whether the emerged bodily fluid 160 is increasing in
size, increasing in size at a particular rate, or exceeds a
particular volume or mass. By way of non-limiting examples, the
detector 120 can detect the volume or mass of the emerged bodily
fluid 160 either directly, indirectly, actively or passively
through the use of sonar, electromagnetic radiation, photometric
evaluation, thermal detection, electro-optical evaluation, and/or
electrochemical evaluation. The sensing techniques can determine
the amount a particular sensing medium is absorbed, dispersed,
scattered, attenuated, refracted, reflected, fluoresced or
diffused. Additionally, the known rate of change of a particular
property of the emerged bodily fluid 160, such as temperature by
way of nonlimiting example, may be detected to determine volume or
mass. In certain embodiments, the detector 120 utilizes the size of
the collection chamber 104 in making the volume or mass
determination.
[0055] As previously mentioned, the detector 120 in one embodiment
includes an ultrasonic detector that detects the amount of fluid
based on the ultrasonic resonance of the collection chamber 104
when placed against the skin 106. The detector 120 in this
embodiment includes a transducer that generates an ultrasonic field
in the collection chamber 104 and a receiver that monitors the
ultrasonic field. Once the skin 106 is lanced, the detector 120
monitors the ultrasonic field for changes. As body fluid 160
emerges from the incision 165, the volume of air inside the
collection chamber 104 is reduced, which changes the resonance of
the ultrasonic field inside the chamber 104 (in a manner analogous
to a wind instrument). The controller 150 and/or the detector 120
maintains records of the correlation between changes in the
resonance of the ultrasonic field and the reduction of the air
volume in the collection chamber 104. As should be appreciated, the
reduction of air volume in the collection chamber 104 is inversely
proportional to the volume of body fluid 106 inside the collection
chamber 104. That is, as more body fluid 160 fills the chamber 104,
less air occupies the collection chamber 104, which in turn changes
the resonance of the collection chamber 104. Based on the change of
the resonance of the chamber 104, the detector 120 is able to
detect the adequacy of the body fluid sample. Although the detector
120 is described as making the determination as to the sufficiency
of the sample, it should be understood that the controller 150 in
other embodiments make this determination based on readings
received from the detector 120.
[0056] When in stage 208 the detector 120 determines that a
sufficient amount of body fluid 160 has collected on the skin 106,
the controller 150 causes the collection member actuator 135 in
stage 208 to extend the collection device 130 so that the body
fluid 160 is collected via the dosing opening 132, as is
illustrated in FIG. 4. As noted above, the collection device 130
can collect the body fluid 160 in a number of manners, such as by
drawing the body fluid 160 via capillary action, a vacuum or a
combination of both, for example. After the body fluid sample is
collected, the testing device 140 analyzes the sample, and the
controller 150 provides the results of the analysis to the user via
the I/O device 157.
[0057] On the other hand, when the detector 120 detects that the
sample of body fluid 160 on the skin 106, the inadequate fluid
sample problem is addressed in stage 210, as is depicted in FIG. 5.
The sampling device 100 in one embodiment considers the sample to
be inadequate when a threshold fluid amount is not reached within a
specified period of time. In another embodiment, the fluid sample
is considered insufficient when the amount of fluid has not
increased at a significant rate within a certain time interval. A
combination of these two techniques can also be used to detect
sufficiency in other embodiments. It is further envisioned that
other parameter can be used to determine that the amount of fluid
was inadequate for testing purposes. For example, the sampling
device 100 in another embodiment does not set time limits for
determining sample adequacy. Rather, the sampling device 100
continuously addresses the insufficiency of the body fluid 160 in
stage 210, such as by expressing fluid, until an adequate amount of
body fluid 160 is detected on the skin 106 in stage 206.
[0058] In stage 210, the insufficiency of the body fluid sample can
be addressed automatically by the sampling device 100, or by a
combination of both automatic and manual techniques. In one
embodiment, the expression device 145 is used to express additional
fluid 160 from the incision 165 in stage 210. Expression device
145, as noted before, can use a variety of techniques to express
additional body fluid 160 from the incision 165, such as by way of
nonlimiting example, thermal heating, vacuum, mechanically pressing
the skin 106, electrical stimulation, vibration, and/or kneading.
For example in one embodiment, after an inadequate amount of body
fluid 160 is detected, the controller 150 activates in stage 210
the expression device 145 to electrically stimulate the skin 106 so
as to express additional fluid 160 from the incision 165. While the
expression device 145 expresses the body fluid 160, the detector
120 monitors the amount of body fluid 160 on the skin 106. Once an
adequate amount of fluid 160 is detected, the controller 150
deactivates the expression device 145, and the body fluid 160 is
collected in stage 208. In another embodiment, the controller 150
deactivates the expression device 145 before detecting the amount
of body fluid 160 on the skin with the detector 120. For instance,
when the body fluid 160 is expressed through mechanical pressure,
readings from the detector 120 may become distorted by misshapening
of the skin 106. This especially can occur when detecting fluid 160
ultrasonically.
[0059] After each failure in stage 206, the sampling device 100 can
continue to use the same technique to draw additional fluid 160
from the incision 165 or can vary the technique used. For example,
after failing to draw a sufficient amount of fluid 160, the
controller 150 via the I/O device 157 in one embodiment instructs
the user to manually press the device 100 against the skin 106 in
an attempt to express additional fluid 160. In stage 210, the
lancet 110 can be also used to draw additional fluid 160 onto the
skin 106. In one embodiment, after forming the incision in stage
204, the lancet 110 remains in the incision 165 to brace the
incision 165 open, thereby allowing additional body fluid 160 to
flow from the incision 165. While in the incision 165, the lancet
110 can for example be moved, rotated, reciprocated, and/or
vibrated to draw additional fluid 160. In another embodiment, the
lancet 110 re-lances the skin 106 in order to improve the amount of
body fluid 160 on the skin 106. In one form, the lancet 110 lances
at the same incision 165 again, but at a greater depth in order to
improve the chances of cutting a sufficient number of capillaries
in the skin 106. In another form, the controller 150 repositions
the lancet 110 within the device 100, or uses a second lancet 110
that is offset from the first lancet 110, and fires the lancet 110,
so that a second incision is formed that is offset from the
original incision 165. The lancet 110 in still yet a further form
is reoriented to an oblique angle relative to the skin 106 so that
an obliquely angled incision 165 is formed in the skin 106, which
increases the chance of cutting more capillaries. In stage 210, the
sampling device 100 can use a delay feature in which no action is
taken so as to allow the body fluid 160 to naturally emerge from
the incision 165 for a period of time.
[0060] As previously mentioned, the user can intervene in stage 210
so as to manually address the insufficient fluid problem. For
example in one embodiment, once the controller 150 determines that
an insufficient amount of body fluid 160 is present, the controller
150 alerts the user to the problem with the I/O device 157. As
should be appreciated, the user in stage 210 can address the fluid
insufficiency problem in many ways. Upon being alerted, the user
can press the sampling device 100 against the skin 106 so as to
express additional fluid 160 from the incision 165, for example. In
another manner, the user can remove the sampling device 100 from
the skin 106 so as to minimize constriction of fluid flow within
the skin 106 towards the incision 165. After predetermined amount
of time, the sampling device 100 can instruct the user to again
place the sampling device 100 over the incision 165 so that the
body fluid 160 can be collected (stage 208). In still yet another
embodiment, upon determining that the amount of fluid 160 is
insufficient, the sampling device 100 instructs the user to
reposition the sampling device 100 over a different part of the
skin 106, away from the incision 165. Once repositioned, the
sampling device 100 forms a second incision (stage 204), detects
the adequacy of the fluid sample (stage 206), and if needed,
addresses any insufficient fluid problems (stage 210) before
collecting the fluid 160 (stage 208). The sampling device 100 in a
further form is configured to permit a manual override by the user.
Even if the sampling device 100 detects an insufficient amount of
fluid, the user through the I/O device 157 can still command the
sampling device 100 to collect the body fluid 160.
[0061] It is envisioned that a combination of manual and automatic
techniques can be used to address the insufficient fluid problem.
In one embodiment, the sampling device 100 first attempts to
automatically address the insufficient fluid problem in stage 210
before requesting user intervention. For instance, the sampling 100
can initially express fluid by electrically stimulating the skin
106 with the expression device 145, and after a predetermined
number of attempts and/or a specified time period, the sampling
device 100 alerts the user to the problem with the I/O device 157
so that the user can manually address the problem in stage 210. In
another embodiment, the sampling device 100 is configured to allow
the user to first manually address the problem before the sampling
device 100 automatically addresses the problem in stage 210.
Further, it is contemplated that the sampling device 100 can
utilize a combination of the above-described techniques at the same
time in stage 210. For instance, the user can manually press the
device 100 against the skin 106, while at the same time, the
expression member 145 electrically stimulates the skin 106.
[0062] With the detector 120, the sampling device 100 is able to
detect the sufficiency of the fluid sample before the body fluid
160 is even drawn into the collection device 130, which reduces
waste. For example, test strips are not wasted, when the collection
device 130 uses a test strip to collect the fluid. Also, when in an
automatic operation mode, the sampling device 100 is able to obtain
a sufficient amount of fluid without the need of removing the
device 100 from the skin 106. If for instance the device 100 was
removed from the skin 106, or even slightly moved, the automatic
collection of the body fluid 160 in a consistent manner can be
difficult. Upon removal of the sampling device 100, the collection
device 130 can become misaligned with respect to the body fluid 160
from the incision 165 so that the dosing opening 132 is unable to
contact the fluid 160 when extended.
[0063] It is envisioned that the sampling device 100 is robust
enough to handle the situation in which the user accidentally
removes the sampling device 100 from the skin 106. For example, if
the sampling device 100 is accidentally removed after the skin 106
is lanced, the user can reposition the sampling device 100 over the
incision site so that the sampling device can detect the
sufficiency of the fluid, express any additional fluid (if needed),
sample the fluid and analyze the fluid. In still yet another
example, where the sampling device 100 is accidentally removed from
the skin 106 after an insufficient amount of fluid is detected, the
user can manually express the fluid from the skin 106 such as by
squeezing the skin 106. Afterwards, the user can manually collect
the fluid with a test strip, for example, or the sampling device
100 can be repositioned over the incision site so as to
automatically collect and analyze the fluid.
[0064] As mentioned previously, an integrated lancing test strip
can be used to sample and analyze fluid using the above-described
techniques. An integrated lancing test strip 230, according to one
embodiment, that can be used in conjunction with the
above-described techniques is illustrated in FIGS. 6, 7 and 8. It
should be recognized that the previously described sampling device
100 can be modified to sample fluid with the illustrated integrated
lancing test strip 230. The integrated lancing test strip 230 in
the illustrated embodiment shares a number of components in common
with those described in U.S. Patent Application No. 11/070,502,
filed Mar. 2, 2005, which is incorporated by reference in its
entirety, and for the sake of clarity as well as brevity, these
common components will not be described in great detail below.
[0065] In one embodiment, the integrated lancing test strip 230 in
one form incorporates a fluid detector that senses whether the body
fluid bled from an incision is sufficient enough for testing
purposes. During sampling, body fluid can tend to smear or
splatter, which in turn can contaminate the fluid detector or other
components inside the sampling device. Once contaminated, the fluid
detector has to be cleaned and sterilized. By having the fluid
detector incorporated into the integrated lancing test strip 230,
the need to clean the detector after every use is eliminated
because the contaminated detector is disposed of after every test.
There is a trend that as test strip technology improves the
required sample sizes for testing become smaller. With the fluid
detector incorporated on the integrated lancing test strip 230, the
fluid detector can be configured to detect fluid sample sizes that
are specifically needed for the integrated lancing test strip 230.
Thus, as test strip technology improves, the user does not have to
necessarily purchase a new sampling device or meter in order to
gain the benefits of smaller sample sizes. Further, with the
detector positioned on the integrated lancing test strip 230,
smaller sample sizes can be detected without having the detector
interfere with fluid collection. The integrated lancing test strip
230 can be placed into close proximity to the sample such that
smaller sample sizes can be readily detected. Further, the detector
allows the integrated lancing test strip sense its position so as
to enhance fluid collection by allowing accurate positioning of the
integrated lancing test strip 230. Although the test strip in the
illustrated embodiment incorporates a lancet, it should be
recognized that the fluid detector can be incorporated into other
types of test strips that do not have lancets.
[0066] As depicted in FIGS. 6 and 7, the integrated lancing test
strip 230 includes a lancet assembly or incision forming member 232
with a moveable lancet needle 233 for forming an incision in
tissue, a sterility sheet or foil 234 for maintaining the sterility
of the lancet 232, and a test strip 236 for acquiring a body fluid
from the incision. The lancet needle 233 has an opening where the
firing mechanism engages the needle 233 when lancing the skin.
During lancing the lancet needle 233 slides within the lancet
assembly 232 and punctures the sterility sheet 234. After forming
the incision, the needle 233 is retracted back inside the sterility
sheet 234. Both the lancet 232 and the test strip 236 in the
illustrated embodiment are generally flat such that the integrated
lancing test strip 230 has an overall flat appearance. By being
flat, multiple integrated lancing test strips 230 can be
incorporated into magazines, cassettes, drums, cartridges and the
like, which allows a plurality of integrated lancing test strips
230 to be used without the need to individually load and/or dispose
of used integrated devices 230. For example, the overall flat shape
allows multiple integrated lancing test strips 230 to be stacked
upon one another in a magazine or rolled around a reel in a
cassette. Furthermore, the overall flat shape allows the integrated
lancing test strip 230 to be manufactured with a continuous process
in which layers of component materials can be layered to form
contiguous strips of integrated lancing test strips 230 that can be
cut to form individual units or remain attached for use in
cassettes and the like. It should nonetheless be recognized that
the integrated lancing test strip 230 in other embodiments can have
a different overall shape.
[0067] In the illustrated embodiment, the test strip 236 is an
electro-chemical type test strip. In one particular form, the test
strip 236 includes a modified version of an ACCU-CHEK.RTM. brand
test strip (Roche Diagnostics GmbH), but it is envisioned that
other types of test strips can be used. For example, the test strip
236 in other embodiments can include an optical type test strip or
can analyze fluid samples in other manners. At one end, the test
strip 236 in the illustrated embodiment includes a connection
portion 238 with electrical contacts 240 that transmit sample
readings to a meter, as is shown in FIGS. 6 and 7. Opposite the
connection portion 238, the test strip 236 has a capillary channel
242 with a capillary opening 244 that is configured to draw a body
fluid sample from an incision formed by the lancet 232 via
capillary action. As should be appreciated, the test strip 236
inside the capillary channel 242 includes an analysis region with
electrodes, like working, counter and reference electrodes, and
reagents for analyzing the fluid sample. In one form, the
connection portion 238 is connected to a meter, and the sample
readings from the electrodes in the analysis region are transmitted
to the meter via the electrical contacts 240.
[0068] With continued reference to FIGS. 6 and 7, at the end
opposite the connection portion 238, the test strip 236 has a fluid
detector 246 for sensing the amount or rate of emergence of body
fluid from an incision. The detector 246 can also be used for range
finding purposes to locate the position of the test strip 236
relative to the skin and/or the drop of body fluid. It should be
appreciated that in other embodiments features from the integrated
lancing test strip 230 can be incorporated into systems in which
all or part of the detector 246 is separate from the test strip
236. In the illustrated embodiment, the detector 246 includes a
pair of sensors 248 that are positioned on opposite sides of the
capillary opening 244. However, it is contemplated that the
detector 246 in other embodiment can include one or more sensors
248. Further, the sensors 248 in other embodiments can be
positioned at other locations on the integrated lancing test strip
230. For example, it is contemplated that all or part of the
detector 246 can be located on the lancet 232, or the detector 246
can be positioned away from the capillary opening 244. The sensors
248 are operatively coupled to the electrical contacts 240 so that
the readings from the detector 246 can be transferred to the
sampling device or meter. In one embodiment, the sensors 248 act
like capacitor plates that measure the capacitance between the
detector 246 and the surface of the skin or tissue. As body fluid
bleeds from an incision, the space between the surface of the skin
and the sensors 248 fills with body fluid, which in turn changes
the capacitance between the detector 246 and the skin. With the
capacitance measurements, the sampling device is able to determine
the flow rate and/or amount of body fluid from the incision.
Furthermore, the sampling device can use the capacitance
measurements for range finding so as to determine the distance
between the end of the test strip 236 and the skin. This can be
used to ensure that the capillary opening 244 is positioned
properly to collect fluid. For instance, if the test strip 236 is
pressed too hard against the skin, fluid flow from the incision
could become constricted. On the other hand, if the test strip 236
is positioned too far away, the capillary channel 242 in the test
strip 236 will not be able to collect the fluid. Alternatively or
additionally, the capacitance between the sensors 248 is measured
to determine whether the drop of body fluid has reached the
capillary opening 244.
[0069] In another embodiment, the sensors 248 act as electrical
contacts so that when a sufficient amount of fluid collects on the
skin, the fluid contacts the sensors 248, thereby closing an
electrical circuit between the sensors 248 and the skin. In another
form, the detector 246 senses the fluid amount by detecting closure
of a circuit between the sensors 248, which occurs when the fluid
is about to fill the capillary channel opening 244. It is
contemplated that detector 246 in other embodiments can use light
or thermal imaging to detect fluid sufficiency. For instance, one
the sensors 248 emits light and the other sensor detects the light.
In one particular example, one of the sensors 248 is an LED that
shines light towards the skin, and the other sensor 246 is a light
detector, such as a photodiode or a CCD, that senses light
reflected from the skin. Based on the sensed light, the sampling
device is able to determine the amount or rate of body fluid bled
from the incision. Again, these light based sensors can be used for
location determination purposes, such as through a PSD.
Alternatively or additionally, the sensors 248 sense the body fluid
by shining the light between the sensors 248 so that the fluid is
detected when the light beam across the capillary channel opening
244 is broken. It is contemplated that in still other embodiments
the sensors 248 can use ultrasonic detection for both fluid
sufficiency detection as well as range finding for the test strip
236. Nevertheless, it should be appreciated that combinations of
the above-described techniques can be used as well as other
techniques can be used to sense the body fluid.
[0070] An enlarged partial cross sectional view of the integrated
lancing test strip 230 during fluid detection is illustrated in
FIG. 9. As shown, the integrated lancing test strip 230 is
incorporated in a sampling device or meter 250. Like the FIG. 1
embodiment, the sampling device 250 in FIG. 9 includes firing
mechanism 115 that is coupled to the connection portion 238 of the
integrated lancing test strip 230. Via communication pathways 155,
the firing mechanism 115 is operatively coupled to controller 150,
and the controller 150 is operatively coupled to I/O device 157.
This forms an operative connection between the integrated lancing
test strip 230 and the controller 150 so that fluid detection
information and test results, as well as other information, can be
communicated between the integrated lancing test strip 230 and the
controller 150. As depicted, the sampling device 250 includes
housing 101 with collection chamber 104 in which the integrated
lancing test strip 230 is disposed. Expression device 145 for
expressing fluid is disposed around the opening of the collection
chamber 104. In the illustrated embodiment, the expression device
145 includes one or more electrodes 252 that are operatively
coupled to the controller 150 so as to utilize electrical
stimulation to enhance bleeding and reduce pain associated with
lancing. For examples of electrode configurations, please refer to
U.S. patent application No. 10/791,173, filed Mar. 2, 2004, that is
entitled "Method and Apparatus for Electrical Stimulation to
Enhance Lancing Device Performance" (attorney docket number
7404-613), which is hereby incorporated by reference in its
entirety. Before lancing the skin 106, the electrodes 252 can
electrically stimulate the skin at various frequencies and voltages
to dilate the vessels in the skin 106 as well as deadened pain
receptors in the skin 106. After the lancet needle 233 creates the
incision 165, the electrodes 252 electrically stimulate the skin
106 to enhance fluid flow of the body fluid 160 from the incision
165. It should be recognized that other types of fluid expression
techniques, such as vacuum and/or pressure based expression
techniques, can be used along with electrical stimulation.
Alternatively or additionally, the skin 106 can be re-lanced with a
greater penetration depth, with a change in lancing angle and/or at
a different location.
[0071] In conjunction with the detector 246 on the integrated
lancing test strip 230, the electrodes 252 in one embodiment are
used to determine the sufficiency of the body fluid 160 from the
incision 165. Before the incision 165 is formed, the electrodes 252
apply a voltage to the skin 106 (via a direct and/or alternating
current), and the sensors 248 on the integrated lancing test strip
230 measures the capacitance between the sensors 248 and the skin,
either directly or indirectly. For instance, the sensors 248 in one
form are used to measure the cut off frequency when the electrodes
252 apply an alternating current at a specified frequency to the
skin 106 (i.e., acts like a band pass filter). In one form, the
controller 150 uses the readings before lancing as a base line for
determining body fluid sufficiency as well as for location
determination purposes, if needed. To enhance accuracy, the user
prior to use can load calibration test strips that have spacing
members or portions at their ends with known dielectric properties
and known spacing distances so that the controller 150 can be
calibrated to the individual. The spacing portions on the ends of
the calibration test strips create a specific distance and
dielectric value between the skin 106 and the sensors 246 so that
controller 150 is able to account for variations in skin
properties. It is contemplated that in other embodiments the
calibration test strips may not be needed. During lancing, the
firing mechanism 115 extends the lancet needle 233 from the
integrated lancing test strip 230 to form the incision 165, and
subsequently, retracts the lancet needle 233. In one form, the
electrodes 252 stimulate the skin 106 as the skin 106 is lanced,
and in other forms, the electrodes 252 do not stimulate the skin
106 prior to or during lancing.
[0072] Once the incision 165 is created, the electrodes 252 apply
to the skin 106 a specified electrical signal, such as having a
specific voltage, current and/or frequency, and the detector 246
via the sensors 248 measure the capacitance between the sensors 248
and the skin 106. It should be appreciated that in further
embodiments other electrical properties, like resistance, impedance
and/or inductance, can be used to detect the amount of body fluid
160. As the body fluid 160 emerges from the incision, the
dielectric properties of the body fluid 160 changes the capacitance
level between the sensors 248 and the skin 106. The expression
device 145 via the electrodes 252 or in some other manner, such as
through a vacuum, continues to express body fluid 160 from the
incision 165, until a specified change in capacitance level from
the base line is achieved. At the specified level, the controller
150 considers the amount of fluid 160 on the skin 106 to be
sufficient for fluid collection. In other forms, the controller 150
monitors the rate at which capacitance changes in order to
determine flow rate of the body fluid 160. Once the designated
change in capacitance is achieved, indicating that a sufficient
amount of fluid is available for collection or flowing at a
sufficient rate to eventually reach the desired sampling amount,
the controller 150 ceases expression of the body fluid 160, if so
desired, and initiates fluid collection.
[0073] To collect the body fluid 160, the controller 150 through
the firing mechanism 115 moves the capillary channel opening 244 of
the integrated lancing test strip 230 towards the skin 106. As the
integrated lancing test strip 230 moves, the controller 150 in one
embodiment monitors the capacitance readings from the sensors 248
to locate the position of the capillary channel opening 244. As
mentioned before, if the channel opening 244 is positioned too far
away from the drop of fluid 160, the integrated lancing test strip
230 will not be able to collect the body fluid 160, but if the
integrated lancing test strip 230 is pressed too close or hard
against the skin 106, fluid flow to the incision 165 can become
constricted. When the sampling device 250 is pressed against the
skin 106, the skin 106 can tend to bulge, which can change the
distance between the channel opening 244 and the skin 106, and due
to variations in elasticity in the skin 106, the bulging of the
skin 106 can vary from body part to body part and/or from person to
person. By performing proximity detection with the detector 246,
the controller 150 is able to position the integrated lancing test
strip 230 close enough to the skin 106 to collect the body fluid
160, but not too close so as to constrict fluid flow. As should be
recognized, the proximity or range detection feature can also be
used during lancing to control the penetration depth of the lancet
232 by compensating for bulging of the skin 106. Moreover, it is
contemplated that the electrodes 252 can be optional in other
embodiments. For example, to detect fluid sufficiency, a known
voltage and/or an alternating current can just be applied to the
sensors 248 in order to sense changes in capacitance, impedance or
other electrical properties as body fluid 160 fills the space
between the skin 106 and the detector 246. Again, it should be
appreciated that the integrated lancing test strip 230 can sense
fluid sufficiency in other manners as well.
[0074] An example of an integrated lancing test strip 260 according
to another embodiment is illustrated in FIG. 10. The FIG. 10
integrated lancing strip shares a number of features in common with
the one described above as well as with the one described in U.S.
patent application No. 11/______, filed Apr. 12, 2005, entitled
"Integrated Lancing Test Strip With Retractable Lancet" (attorney
docket number 7404-685), which is hereby incorporated by reference
in its entirety. For the sake of clarity as well as brevity, the
common features will not be again described in great detail
below.
[0075] As shown in FIG. 10, the integrated lancing test strip 260
includes a test strip 262 that has connector portion 238 with
contacts 240 and a lancet 264 that is coupled the test strip 262.
In the illustrated embodiment, the lancet 264 is fixed to the test
strip 262. However, the lancet 264 in other embodiments is coupled
to the test strip 262 in a moveable manner, such as in the FIG. 6
embodiment. In the FIG. 10 embodiment, the test strip 262 is an
electrochemical type test strip, but it should be once more
appreciated that other types of test strips can be used, such as a
calorimetric type test strip. As can be seen, the lancet 264 is
positioned offset from the central longitudinal axis of the
integrated lancing test strip 260 such that the lancet 264 extends
along one side of the test strip 262, parallel to the longitudinal
axis. To provide a compact profile, the lancet 264 in the depicted
embodiment is generally flat, and the lancet 264 includes a lancet
tip 266 for forming an incision in tissue. In the illustrated
embodiment, the integrated lancing test strip 260 has fluid
detector 246 for sensing the sufficiency of the body fluid on the
tissue, and the fluid detector 246 in the depicted example includes
the lancet 264. In the illustrated embodiment, the lancet 264 is
made of a conductive material and is operatively coupled to one or
more of the contacts 240 at the connection portion 238, which in
turn are operatively coupled to the controller 150 via firing
mechanism 115. The lancet 264 acts like an electrical contact so
that when the body fluid reaches the lancet tip 266, an electrical
circuit is formed such that the controller 150 is able to detect
fluid sufficiency based on the closure of the circuit. In another
embodiment, it is contemplated that the detector 246 for the
integrated lancing test strip 260 of FIG. 10 can, additionally or
alternatively, include the sensors 248 of the type described above
with reference to FIG. 6.
[0076] Referring to FIG. 10, the test strip 262 defines a capillary
channel 268 that has an analysis portion with electrodes and
reagents for analyzing the fluid sample. The capillary channel 268
has an opening 270 that is offset from the longitudinal axis of the
test strip 262 and slanted at an angle relative to the longitudinal
axis. In one form, the angle between the capillary opening 270 and
the longitudinal axis is an oblique angle. As shown, the capillary
channel 268 has a boomerang shape, and the capillary channel
opening 270 is Y-shaped with a curved opening. However, it is
envisioned that the channel 268 can be shaped differently in other
embodiments. The illustrated test strip 262 has a generally
rectangular shape, with the exception that the test strip 262 has a
truncated corner 272 at the capillary channel opening 270. The
truncated corner 272 allows the capillary channel opening 270 to be
rotated over the incision site without having the test strip 262
contacting the skin or the body fluid drop, which could potentially
smear the drop of fluid.
[0077] By having the ability to rotate the lancet 264 out of the
way, the capillary channel 268 is able to collect the fluid sample
without the lancet 264 interfering with the sample collection. In
some embodiments, the integrated lancing test strip 260 is rotated
between 30.degree. to 180.degree. to collect the fluid sample. To
minimize the rotation of the test strip 262, the lancet 264 and the
capillary channel 268 are located near the same end of the test
strip 262. It is nonetheless contemplated that the lancet 264 and
the capillary channel 268 can be positioned differently for other
embodiments. For example, the orientation of the lancet 264 and the
capillary channel 268 can be reversed such that the capillary
channel 268 extends parallel to the longitudinal axis and the
lancet 264 extends in a nonparallel manner relative to the
longitudinal axis. The integrated lancing test strip 260 in one
form is rotated manually by the user after the incision is formed,
and in another form, the meter automatically rotates the integrated
lancing test strip 260. To automatically rotate the integrated
lancing test strip 260, the integrated lancing test strip 260
includes a coupling structure 274 that allows the firing mechanism
115, actuator 135, or some other type of device, to rotate the
integrated lancing test strip 260. In the illustrated embodiment,
the test strip 262 has one or more engagement holes 276 through
which the test strip 262 is held and rotated. It is envisioned that
other types of coupling structures with different configurations
can be used to rotate the integrated lancing test strip 260.
[0078] Referring now to FIGS. 11, 12 and 13, there is illustrated
the various stages for collecting and analyzing a body fluid sample
with the integrated lancing test strip 260. With reference to FIG.
11, the integrated lancing test strip 260 is loaded into sampling
device or meter 250 that is similar to the ones shown in FIGS. 1
and 9 with the connection portion 238 coupled to the firing
mechanism 115. Like before, the expression member 245 includes one
or more electrodes 252 that are operatively coupled to the
controller 150, but it again should be appreciated that fluid can
be expressed using other types of expression devices. In one
embodiment, the electrodes 252, the skin 106, body fluid 160 and
the lancet 264 are used to form a circuit with the controller 150
for sensing fluid sufficiency via resistance or other electrical
property. In another embodiment, the electrodes 252 are optional
such that fluid sufficiency is detected when the lancet 264 is
grounded upon contacting the body fluid 160. If so desired, the
expression member 245 can stimulate the skin prior to and/or during
lancing to stimulate fluid flow or deaden pain. As shown in FIG.
11, the lancet 264 lances the skin 106 by having the entire
integrated lancing test strip 260 fired towards the skin 106 by the
firing mechanism 115. During lancing, the controller 150 can sense
for misfiring of the integrated lancing test strip 230 by
determining if a circuit was formed between the lancet 264 and the
skin 106. If the circuit does not close while lancing, the
controller 150 can re-fire the lancet 264 or take other appropriate
actions to correct the problem.
[0079] After the incision 165 is created, the controller 150 via
the firing mechanism 115 retracts the lancet 264 a specified
distance from the surface of the skin or tissue 106. To promote
fluid flow from the incision 165, as is illustrated in FIG. 12, the
controller 150 in one form activates the expression device 245
prior to, during and/or subsequent to lancing to enhance flow of
the body fluid 160 from the incision 165. The controller 150
continues the expression of fluid until the body fluid 160 contacts
the lancet tip 266, which is an indication that a sufficient sample
size has collected on the skin 106. In another form, the controller
150 delays initiation of expression for a specified time so as to
give the body fluid 160 the ability to naturally emerge from the
incision 165. After the specified time period elapses, if the body
fluid 160 does not contact the lancet 264, then the controller
activates the expression device 245 to express additional fluid 160
until contact between the lancet 264 and the fluid 160 is
established. Once a sufficient amount of fluid 160 collects on the
skin 106, the entire integrated lancing test strip 260 is rotated
so that the capillary channel 268 is able to collect body fluid 160
from the incision 165, as is depicted in FIG. 13. The test strip
262 is rotated such the lancet 264 moves away giving a clear path
for the capillary 268 of the test strip 262 to contact the body
fluid 160. In the embodiment where the lancet 264 is not fixed to
the test strip 262, the lancet 264 can be retracted inside the
integrated lancing test strip 260 so as to further reduce the
chance of the lancet 264 interfering with fluid collection and the
risk of accidentally stabbing oneself with the lancet 264. The
integrated lancing test strip 260 can be rotated manually by the
user, for example by repositioning the entire meter 250, or the
entire integrated lancing test strip 260 can be rotated
automatically by the firing mechanism 115.
[0080] Upon rotation, the firing mechanism 115 moves the capillary
channel opening 270 towards the body fluid 160, and the body fluid
160 is then drawn by the capillary channel 268 into the analysis
area where the sample is analyzed. In another embodiment, the
integrated lancing test strip 260, alternatively or additionally,
includes one or more of the previously described sensors 248
positioned at the capillary channel opening 270 in order to sense
fluid sufficiency and/or locate the capillary channel opening 270.
For example, the integrated lancing test strip 260 in one form
employs a two-step sensing technique in which the lancet 264 senses
initial fluid sufficiency and the sensors 248 double check the
fluid sufficiency reading. If the sensors 248 sense that the fluid
amount or flow rate is insufficient for testing, the controller 150
can activate the expression device 245 so as to express more body
fluid 160. Fluid 160 can also be expressed in the manner as was
described with reference to FIG. 5. When an insufficient amount of
the body fluid 160 is present, I/O device 157 can also indicate
fluid insufficiency to prevent premature removal of the meter 250.
In the illustrated embodiment, the integrated lancing test strip
260 is connected to the meter 250 through the strip connector 238,
and the results from the analysis are transferred to the meter 250
through the connector 238. Results from the analysis are presented
with the I/O device 157 and/or transferred to a computer for
further analysis.
[0081] While the invention has been illustrated and described in
detail in the drawings and foregoing description, the same is to be
considered as illustrative and not restrictive in character, it
being understood that only the preferred embodiment has been shown
and described and that all changes and modifications that come
within the spirit of the invention are desired to be protected. All
publications, patents, and patent applications cited in this
specification are herein incorporated by reference as if each
individual publication, patent, or patent application were
specifically and individually indicated to be incorporated by
reference and set forth in its entirety herein.
* * * * *