U.S. patent application number 13/717668 was filed with the patent office on 2013-05-02 for method for constructing a blood glucose sampling device.
The applicant listed for this patent is Clifton A. Alferness. Invention is credited to Clifton A. Alferness.
Application Number | 20130104369 13/717668 |
Document ID | / |
Family ID | 47325223 |
Filed Date | 2013-05-02 |
United States Patent
Application |
20130104369 |
Kind Code |
A1 |
Alferness; Clifton A. |
May 2, 2013 |
Method For Constructing A Blood Glucose Sampling Device
Abstract
A method for constructing a blood glucose sampling device is
provided. A housing sized to accommodate a lancet and a removable
sensor cartridge is formed. The sensor cartridge includes test
strips and cleaning elements. A movable outer grip is defined along
a circumference of the housing and is shaped to conformably fit
within a hand of a user. A test passage is formed in the outer grip
in which one of the test strips and the lancet are aligned.
Inventors: |
Alferness; Clifton A.; (Port
Orchard, WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Alferness; Clifton A. |
Port Orchard |
WA |
US |
|
|
Family ID: |
47325223 |
Appl. No.: |
13/717668 |
Filed: |
December 17, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12575405 |
Oct 7, 2009 |
8333715 |
|
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13717668 |
|
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61195352 |
Oct 7, 2008 |
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Current U.S.
Class: |
29/428 ;
29/592 |
Current CPC
Class: |
A61B 5/150358 20130101;
A61B 5/15117 20130101; A61B 5/150274 20130101; A61B 5/150519
20130101; A61B 5/150755 20130101; A61B 5/150022 20130101; A61B
5/150068 20130101; A61B 5/14532 20130101; A61B 5/15161 20130101;
A61B 5/150229 20130101; A61B 5/150412 20130101; A61B 5/1513
20130101; A61B 5/150099 20130101; A61B 5/15113 20130101; A61B
5/1519 20130101; Y10T 29/49826 20150115; A61B 5/150259 20130101;
A61B 5/15196 20130101; Y10T 29/49 20150115; A61B 5/157 20130101;
A61B 5/150824 20130101 |
Class at
Publication: |
29/428 ;
29/592 |
International
Class: |
A61B 5/15 20060101
A61B005/15 |
Claims
1. A method for constructing a blood glucose sampling device,
comprising: forming a housing sized to accommodate a lancet and a
removable sensor cartridge comprising test strips and cleaning
elements; defining a movable outer grip along a circumference of
the housing that is shaped to conformably fit within a hand of a
user; and forming a test passage in the outer grip in which one of
the test strips and the lancet are aligned.
2. A method according to claim 1, further comprising: orienting the
test strips in a common direction of rotation about a central point
of the sensor cartridge, wherein each test strip comprises a test
region defined radially from the mount opening at a proximal end
and a capillary aligned with a distal end of the test region and
extending away from the mount opening; alternately interposing the
cleaning elements between the test strips in the common direction
of rotation; and aligning the lancet with at least one of the test
strips.
3. A method according to claim 1, further comprising: forming a
cartridge mount on an inside surface of the housing.
4. A method according to claim 1, wherein the outer grip comprises
at least one of nitinol wire and foam.
5. A method according to claim 1, further comprising: affixing a
pivoting cover to a substantially open side of the housing.
6. A method according to claim 5, further comprising: providing a
display on the cover.
7. A method according to claim 6, wherein the display provides at
least one of blood glucose measurements, time, and date.
8. A method according to claim 1, further comprising: installing
one or more actuators around the outer grip of the housing.
9. A method according to claim 8, wherein the actuators each
comprise one of a pushable button, toggle, and switch.
10. A method according to claim 1, further comprising: affixing a
mounting band to the housing.
11. A method for constructing a blood glucose sampling device,
comprising: building a sensor cartridge comprising a plurality of
blades oriented in a common direction of rotation about a central
point, wherein each blade comprises a test strip and a cleaning
element positioned adjacent to the test strip; and forming a
housing sized to accommodate a lancet and the sensor cartridge, and
comprising a cartridge mount defined on an inner surface of the
housing; and affixing a pivoting cover to a substantially open side
of the housing.
12. A method according to claim 11, wherein the lancet is affixed
to at least one of the sensor cartridge, housing, and a lancet
cartridge.
13. A method according to claim 12, further comprising: affixing
one or more further lancets to at least one of the sensor
cartridge, the lancet cartridge, and the housing.
14. A method according to claim 12, further comprising: forming a
mount opening in each of the sensor cartridge and the lancet
cartridge.
15. A method according to claim 14, wherein the mount openings are
formed at least one of centrally and off-center in the sensor
cartridge and the lancet cartridge.
16. A method according to claim 14, further comprising: placing the
lancet cartridge over the cartridge mount; and placing the sensor
cartridge over the cartridge mount.
17. A method according to claim 11, further comprising: installing
an actuator on an outer surface of the housing.
18. A method according to claim 11, further comprising: forming a
test passage in an outer surface of the housing.
19. A method according to claim 18, wherein the test passage is
shaped to receive a user's finger.
20. A method according to claim 11, wherein the housing comprises
at least one of plastic and metal.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This non-provisional patent application is a continuation of
U.S. patent application Ser. No. 12/575,405, filed Oct. 7, 2009,
pending; which claims priority to under 35 U.S.C. .sctn.119(e) to
U.S. Provisional Patent Application Ser. No. 61/195,352, filed Oct.
7, 2008, the disclosure of which is incorporated by reference.
FIELD
[0002] This application relates in general to sampling devices and,
in particular, to a blood glucose sampling device.
BACKGROUND
[0003] Diabetics, both type I and type II, who take insulin must
measure the levels of their blood glucose at various times to know
how much food or insulin to take to compensate for their present
state. For many years, blood glucose has been measured by taking a
lancing device from a pocket, purse, or testing kit, lancing
through the skin of a patient's finger into the capillary bed,
extracting a small drop of blood onto a test strip, and measuring
the blood glucose concentration using an electronic blood glucose
meter or color chart.
[0004] Specifically, to make this blood glucose measurement, a
fresh test strip is first removed from a carrying case, and
inserted into the blood glucose meter. A lancing device, which has
a spring-loaded point tip or lancet, is then employed to prick
through the skin into the patient's capillary bed, usually on a
fingertip. Sometimes, particularly when the ambient temperature is
cool, the finger must be "milked" or manually squeezed toward or
around the lanced site to get a drop of blood that is large enough
to analyze. This drop of blood is wicked into or placed on the test
strip, where a chemical reaction takes place, which enables the
meter to yield a measurement of the blood glucose concentration in
that blood sample.
[0005] The step of getting the blood onto or into the test strip
usually involves picking up the meter with a test strip already in
place and moving the tip of the test strip to touch the exposed
surface of the drop of blood on the pricked fingertip. The test
strip usually includes a capillary or absorbent material that wicks
the blood onto a glucose oxidase region, where the blood is then
analyzed for blood glucose concentration.
[0006] The resultant blood glucose measurement is displayed on the
meter's display screen, so that the patient can subsequently take
insulin or eat food, as appropriate. Once the analysis of the blood
sample is complete and the result displayed, the patient must use a
tissue or similar material to remove any excess blood on the
fingertip or other site from which the sample was taken. The used
test strip is removed from the meter and carefully discarded. Care
is taken to avoid touching the end of the strip, which still
contains blood. Wiping the end of the strip with a tissue helps to
remove the possibility of unwanted blood stains.
[0007] Conventionally, the taking of a blood sample for blood
glucose measurement involves multiple steps, requires fresh testing
supplies and equipment, specifically a lancing device and blood
glucose meter. The production can take substantial time to complete
for the diabetic. The supplies and equipment must be on-hand
wherever the diabetic goes. Additionally, blood glucose testing is
noticeable by individuals around the patient and is often an
awkward or embarrassing procedure to complete in public settings
due to the drawing of blood, meter usage, and clean up. Therefore,
patients are often compelled to postpone the process to a more
private setting so they are not embarrassed by the obtrusiveness of
the process.
[0008] Attempts to improve the sampling and testing process
self-performed by a patient have been made. For example, U.S.
Patent Application Publication No. 2008/0077048, to Escutia et al.,
teaches a body fluid sampling device to automate milking of a
patient digit to express a sufficient amount of body fluid. The
device includes a catalyst device to apply pressure to the digit
and a footprint. The digit is positioned within the catalyst, which
directs blood to a sampling site on the digit, and over the
footprint. The footprint guides the penetration member to the
digit. However, the patient must remove his digit from the catalyst
to clean up any excess blood.
[0009] U.S. Pat. No. 7,004,928 and U.S. Patent Application
Publication No. 2006/0094985 to Aceti et al. teach a monitoring and
drug delivery device that provides calibration and semi-continuous
monitoring. The device includes a carrier having a plurality of
microneedles, each coupled with a conduit, and a plurality of
microchannels. One of the microneedles penetrates the skin of a
patient and a blood sample is obtained, which enters the associated
microchannel. After the microneedle punctures the skin, the patient
must manually wipe any excess blood with a tissue.
[0010] Further, U.S. Pat. No. 6,540,675, U.S. Pat. No. 6,923,764,
and U.S. Patent Application Publication No. 2004/0202576, also to
Aceti et al., teach an analyte monitor having a plurality of
needles each associated with a chamber configured to hold a blood
sample. The sample is collected into the chamber by piercing the
skin of a patient with the needle. Once collected, an arm including
a detector and light source rotates to the chambers to emit a light
source. An absorbance of the light is detected. Once punctured, the
patient must manually clean any excess blood from the site of the
pierced skin.
[0011] Therefore, a need remains for a blood glucose sampling
device, which could be used by patients without having to assemble
all the various supplies and equipment to accomplish the task of
making a blood glucose measurement. A blood glucose sampling device
that is more discrete would allow patients to make blood glucose
measurements without the embarrassment of nearby people being aware
that the process is taking place.
SUMMARY
[0012] A unitary sampling device impedes venous return from the
blood vessels of the fingertip being tested by built-in pressure
points, and impels blood toward the lancing site so that manual
"milking" of the finger is not needed. The sampling device also
locates the point of lancing of the fingertip whereby the resultant
drop of blood is formed to touch a capillary defined on a far end
of a test strip. The blood travels via the capillary to a test
region covered by an enzyme electrode, including glucose oxidase
and manual matching of the sensor tip to the drop of blood on the
fingertip is not needed. The sampling device also includes a
cleaning element for absorbing the residual blood after the
completion of testing. Tissue paper is not needed to clean the
lanced site.
[0013] A further embodiment provides a blood glucose sampling
device. A sensor cartridge includes a plurality of blades oriented
in a common direction of rotation about a central point. Each blade
includes a test strip having a test region defined radially on a
surface of the test strip from an outer edge of the central point
at a proximal end and a capillary aligned with a distal end of the
test region and extending to an outer edge of the blade. Each blade
also includes a cleaning element positioned adjacent to the test
strip in the common direction of rotation about the central point.
The blades are positioned about the central point such that the
test strip of one blade contacts the cleaning element of another
blade. A lancet is affixed to a lancet cartridge and aligned with
the capillary formed in the test strip. A housing removably
encloses the sensor cartridge and lancet cartridge. The housing
includes an outer grip surrounding a circumference of the housing
and is movably shaped to conformably fit within a hand of a user
between a thumb and a finger. The housing also includes a test
passage formed in the outer grip through which the test strip and
lancet are positioned.
[0014] A further embodiment includes a band attached to a sampling
device that encircles an extremity of a patient, such as a forearm,
and includes a deployable lancet to lance the skin at a preferred
location on the extremity, self-locating the testing strip
capillary at the lanced location, and an enclosure that creates
suction that enhances the formation of a drop of blood. A mountable
blood glucose sampling device is provided. The mountable blood
glucose sampling device includes a sensor cartridge having a
plurality of blades oriented in a common direction of rotation
about a central point. Each blade includes a test strip having a
test region defined radially from the central point at a proximal
end and a capillary aligned with a distal end of the test region
and extending to an outer edge of the blade. The sensor cartridge
also includes a cleaning element positioned adjacent to the test
strip in the common direction of rotation about the central point.
The blades are positioned around the central point such that the
test strip of one blade contacts the cleaning element of another
blade. A lancet is aligned with one of the test strips. A housing
is shaped to removably enclose the sensor cartridge and lancet. The
housing includes a test passage formed on a back side of the
housing through which the aligned test strip and lancet are
positioned. A mounting band is attached to the housing and shaped
to removably accommodate an extremity of a user. A suction element
is affixed to the back side of the housing and formed to contact a
portion of the extremity.
[0015] In yet a further embodiment, a method for constructing a
blood glucose sampling device is provided. A housing sized to
accommodate a lancet and a removable sensor cartridge is formed.
The sensor cartridge includes test strips and cleaning elements. A
movable outer grip is defined along a circumference of the housing
and is shaped to conformably fit within a hand of a user. A test
passage is formed in the outer grip in which one of the test strips
and the lancet are aligned.
[0016] Such devices would encourage patients to make more frequent
and timely blood glucose measurements, thereby enabling them to
improve their response time to blood glucose excursions and
ultimately the control or management of blood glucose.
[0017] Still other embodiments will become readily apparent to
those skilled in the art from the following detailed description,
wherein are described embodiments by way of illustrating the best
mode contemplated. As will be realized, other and different
embodiments and its several details are capable of modifications in
various obvious respects, all without departing from the spirit and
the scope. Accordingly, the drawings and detailed description are
to be regarded as illustrative in nature and not as
restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a top plan view showing a sensor cartridge for use
with a blood glucose sampling device in accordance with one
embodiment.
[0019] FIG. 2 is an exploded view showing a blood glucose sampling
device assembly, including a housing, lancet, and the sensor
cartridge of FIG. 1.
[0020] FIG. 3 is a flow diagram showing, by way of example, a
process for obtaining a blood sample using the blood glucose
sampling device of FIG. 2.
[0021] FIG. 4 is a diagram showing, by way of example, a hand
holding the blood glucose sampling device of FIG. 2 with the
fingers in an initial position of a sampling sequence.
[0022] FIG. 5 is a diagram showing, by way of example, a hand
holding the blood glucose sampling device of FIG. 2 with the
fingers in a testing position of a sampling sequence.
[0023] FIG. 6 is a cross-sectional view of a finger and blood
glucose sampling device of FIG. 5.
[0024] FIG. 7A is a block diagram showing, by way of example,
deployment of a lancet into a finger.
[0025] FIG. 7B is a block diagram showing, by way of example, entry
of a sample into a capillary.
[0026] FIG. 8 is a block diagram showing, by way of example,
rotation of a cleaning element to an impalement site on a
finger.
[0027] FIG. 9 is a block diagram showing a hand holding the blood
glucose sampling device of FIG. 2, which displays results of a
blood sample.
[0028] FIG. 10 is a front plan view of a mountable blood glucose
sampling device.
[0029] FIG. 11 is a cross-sectional view of the mountable blood
glucose sampling device of FIG. 10.
DETAILED DESCRIPTION
[0030] Self-monitoring of blood glucose, such as in diabetes
management, can be a tedious and, at times, socially embarrassing
process. A blood glucose sampling device with built-in lancing,
testing, and cleaning features can allow a patient to easily and
discreetly obtain blood samples and measure the sample's blood
glucose level. The blood glucose sampling device includes a housing
within which a lancet and a sensor cartridge are positioned. FIG. 1
is a top plan view showing a sensor cartridge 10. The sensor
cartridge 10 includes a plurality of blades 11 each having a test
strip 12 and a cleaning element 13. The blades 11 are oriented in a
common direction of rotation around and attached at a central point
14. The test strips 12 and cleaning elements 13 are alternately
positioned. For example, the test strip of one blade contacts both
the corresponding cleaning element for the blade and a cleaning
element of another neighboring blade.
[0031] Each test strip 12 includes an individual test region 15
having enzyme electrodes located at an inner or proximal end of the
test strip 12, nearest to the central point 14. On one surface of
the test strip, a capillary is defined inwardly from an outer edge
or distal edge of the blade and feeds into the testing region. A
lancet (not shown) impales the skin of a patient to obtain a blood
sample for testing. The lancet is aligned with a capillary in a
clean test strip so that the blood enters the capillary and flows
to the testing region. Obtaining a sample using the lancet and test
strip are further discussed below with reference to FIGS. 7A and
7B.
[0032] The cleaning element 13 is positioned adjacent to the test
strip to remove and absorb the excess blood from the fingertip
after the sensor capillary has wicked sufficient blood to complete
testing. Excess blood is removed by manually or automatically
rotating the sensor cartridge so that the cleaning element 13 is
adjacent to the puncture point after completion of the blood
glucose analysis. Rotation can be provided by a motor and the like.
The cleaning element 13 can include an absorbent material, such as
a fabric or open cell sponge material. Other types of absorbent
materials are possible. The cleaning element 13 relieves the
patient from the messy and socially intrusive task of wiping off
the excess blood with a facial tissue or equivalent absorptive
material.
[0033] The sensor cartridge includes a mount opening that is shaped
to be received by a shaft rotatably provided in the device housing
(not shown). The mount opening can be located at the central point
of the sensor cartridge, or alternatively, at another point. The
mount opening is further described below with reference to FIG. 2.
In a further embodiment, the mount opening is keyed to ensure
locking of the sensor cartridge 10 to the shaft.
[0034] The sensor cartridge 10 can be removably enclosed with a
housing. FIG. 2 is an exploded view showing a blood glucose
sampling device assembly, including a housing, lancet, and the
sensor cartridge of FIG. 1. The lancet 23 can be affixed to a
lancet cartridge 26 in which a mount opening 31 is formed centrally
or off-center. The mount opening 31 is shaped to receive a shaft
positioned within the housing 21. The lancet 23 can be affixed
adjacent to an outer edge of the lancet cartridge 26 to allow
extension and retraction of the lancet 23. The lancet 23 is
spring-loadable or otherwise slidably-oriented to facilitate
lancing of the fingertip.
[0035] In a further embodiment, the lancet cartridge 26 and sensor
cartridge 24 can be combined to form a single cartridge, the lancet
23 can be affixed to the sensor cartridge 24, or the lancet 23 can
be affixed to the housing 21. The lancet 23 is be aligned with a
test strip of the sensor cartridge 24.
[0036] In yet a further embodiment, multiple lancets can be
included on the sensor cartridge, lancet layer, or affixed to the
housing so that each lancet corresponds with a blade of the sensor
cartridge. The patient can singly use the corresponding blade and
lancet.
[0037] The housing 21 can be made of materials, including heavy
plastic or metal, and is shaped to enclose the sensor cartridge 24
and lancet cartridge 23. The housing can be opened on one side,
which allows placement and removal of the sensor cartridge 24 and
lancet cartridge 23. The open side can be covered with a door
pivotably or otherwise removably attached to the housing. One or
more displays (not shown) can be affixed to the door or to another
side of the housing for providing readings of the blood samples
collected and analyzed by the sampling device.
[0038] The sensor cartridge 24 and lancet cartridge 23 can be
removably positioned within the housing via a shaft, which forms a
cartridge mount 27. Specifically, the mount openings in the sensor
cartridge 24 and lancet cartridge 23 are placed over the shaft 27
and secured. The shaft 27 can be located centrally or off-center
within the housing 21. When located centrally, the shaft 27 is
positioned at the central point of rotation for the sensor
cartridge 24. The sensor cartridge 24 can rotate within the housing
21 about the central point so that for each test, a new test strip
and cleaning strip are respectively aligned in the test passage
during sampling.
[0039] The outside of the housing includes an outer grip 25 that is
shaped to conformably fit within a hand of a patient. Within the
outer grip 25, a test passage 28 is formed to receive a finger,
through which the lancet and capillary of the test strip are
aligned for obtaining a sample from a patient. An opening of the
test passage formed within the outer grip 25 is shaped to receive a
body part of a patient, such as a finger.
[0040] A sensor cartridge actuator 29 and test actuator (not shown)
can also be included in the outer grip 25. The actuators can
include a pushable button, toggle, or switch, as well as other
mechanisms. The sensor cartridge actuator 29 is located at a
distance from the test passage 28 around the circumference of the
outer grip 25. The placement of the sensor cartridge actuator 29 is
further discussed below with reference to FIGS. 4-8. Upon
selection, the sensor cartridge actuator 29 can advance the sensor
cartridge 24 into position within the housing 21 so that the test
strip of a blade is aligned with the lancet in the test passage 28.
The sensor cartridge can be further advanced in the same direction
so that the cleaning element of the blade is aligned in the test
passage 28. The rotation of the sensor cartridge can be directed by
selection of the sensor cartridge actuator. For example, in one
embodiment, the test strip is aligned in the test passage upon
depression of the sensor cartridge actuator and the cleaning
element is aligned upon release of the same sensor cartridge
actuator. In a further embodiment, the test strip and cleaning
element are aligned in the test passage using separate sensor
cartridge actuators. The sensor cartridge actuator 29 can activate
the display or displays affixed to the housing.
[0041] The test actuator can also be affixed to the outer grip 25
of the housing 21 substantially adjacent to the test passage 28.
Upon selection of the test actuator, the lancet is cocked,
released, and extended through the test passage into the test
passage opening. In one example, the test actuator is a button that
cocks and releases the lancet towards a patient's finger or other
body part upon depression. Once extended, the lancet impales the
finger that is placed over the test passage opening. Then, the
lancet can be retracted upon release of the test button. In a
further embodiment, the release and retraction of the lancet can be
performed upon the selection of separate actuators or upon
selection of the same actuator.
[0042] Depression of the test actuator requires pushing provided by
a test finger of the patient. The pushing accomplishes milking of
the finger, which directs and traps blood in the tip of the test
finger so that the tip is engorged with blood during impalement.
Deployment of the lancet into the fingertip may be performed
multiple times to acquire enough blood necessary to complete a
blood analysis.
[0043] The blood glucose sampling device provides a simple and
efficient process for obtaining and analyzing a blood sample. FIG.
3 is a flow diagram showing, by way of example, a process for
obtaining a blood sample using the blood glucose sampling device of
FIG. 2. The blood glucose sampling device is positioned within a
patient's hand and a test finger is identified. The sampling device
includes a lancet and a sensor cartridge having a plurality of
blades, each including a test strip and cleaning element. Once
positioned, a clean test trip within the blood glucose sampling
device is aligned with the lancet in a test passage formed within
the sampling device (block 41). The sampling device provides
"milking" (block 42) of the test finger so that the fingertip is
engorged with blood. "Milking" can occur through manual means
provided by the patient, by pressure provided by the sampling
device, as further described below with reference to FIGS. 5 and 6,
and by suction pressure generated by the sampling device, as
further described below with reference to FIG. 11.
[0044] A lancet is deployed (block 43) to pierce the skin of the
engorged fingertip for obtaining a blood sample and then retracted
(block 44). The blood sample is collected (block 45) on the test
strip aligned with the lancet. More specifically, the sample enters
a capillary formed on the test strip and travels to a test region
covered with enzyme electrodes. Once collected, a determination
(block 46) is made whether the sample is large enough for analysis.
If not, additional sample blood must be obtained through further
"milking" (block 42) of the test finger. However, if sufficiently
large, the sample is analyzed to determine a blood glucose
concentration. After the test finger has been pierced and the
sample collected, a cleaning element is aligned (block 48) in the
test passage to contact and remove any excess blood remaining. The
analysis (block 47) and cleaning (block 48) can occur concurrently
or sequentially.
[0045] FIGS. 4 through 8 show the sequence of events that occur
using the sampling device for testing blood glucose. FIG. 4 is a
block diagram 50 showing, by way of example, a hand 52 holding the
blood glucose sampling device 51 of FIG. 2 with the fingers in an
initial position of a sampling sequence. The blood glucose sampling
device 51 is shaped to fit within the hand 52 of a patient,
specifically between a finger 54, such as the pointer finger, and
the thumb 53. Other fingers are possible. The finger 54 is selected
by a patient as the test finger 54, from which a blood sample is
obtained. The thumb 53 rests along the outer grip of the blood
glucose sampling device on a sensor cartridge actuator (not shown),
while the test finger 54 wraps around a circumference of the outer
grip, towards a top of the housing. The blood glucose sampling
device 51 rests along webbing of the hand 52 between the thumb 53
and pointer finger. In a further embodiment, the test finger 54 can
include the thumb 53, while one of the fingers controls the sensor
cartridge actuator.
[0046] FIG. 5 is a block diagram 55 showing a hand 57 holding the
blood glucose sampling device 56 of FIG. 2 with the fingers 59 in a
test position of a sampling sequence. The blood glucose sampling
device 51 is positioned within the patient's hand 57 and a test
finger 59 is sequentially wrapped around an outer grip of the
device 56. The test finger 59 rests upon a test actuator (not
shown) and a test passage (not shown) adjacently located in the
outer grip. Meanwhile, the thumb is positioned over a sensor
cartridge actuator, which rotates the sensor cartridge so that a
capillary of clean test strip is aligned with a lancet in the test
passage. Once the blood glucose sampling device is properly
positioned within the patient's hand for testing, tissue pressure
is created in the proximal portion of the test finger, nearest the
palm, by the housing of the blood glucose sensor device. Due to the
pressure, venous return is impeded in that the test finger while
arterial blood continues to flow. This causes an engorgement of
blood in the fingertip as the finger is wrapped around the blood
glucose sampling device and rests upon the test actuator and test
passage. An opening of the test passage formed in the outer grip
allows the tip of the test finger to bulge out adjacent to the
capillary of the test strip positioned within the test passage.
[0047] The pressure is created by a protruding of the outer grip
into the test finger. FIG. 6 shows a cross section of a test finger
and a blood glucose sampling device of FIG. 5. The outer grip or
portions of the outer grip of the housing can be made from nitinol
wire and foam, which allows the outer grip to contract and expand
when pressure is applied. Specifically, to impede venous return, a
side of the outer grip corresponding with the proximal portion of
the test finger protrudes outwards into the test finger based on a
squeezing of the blood glucose sampling device sides adjacent to
the protruding side. The squeezing can be performed by a distal end
of the test finger, such as the fingertip, and the thumb by
pressing the outer grip into the blood glucose sampling device. The
increased tissue pressure within the test finger generated by the
squeezing effectively prevents venous blood flow past the pressure
point while allowing arterial flow. A series of such ribs
accomplishes a sequential milking process.
[0048] Once the blood is collected in the tip of the test finger, a
lancet can be deployed to obtain a sample. FIG. 7A is a block
diagram 70 showing, by way of example, deployment of a lancet 73
into a test finger 72. The test finger 72 of a patient is
positioned upon a test actuator (not shown) and over an opening of
a test passage 76, while the thumb rests upon a sensor cartridge
actuator, as described above with respect to FIG. 5. More
specifically, a tip of the test finger enters the housing through
the opening of the test passage. Meanwhile, the blood glucose
sensing device can rest in the webbing between the thumb and
pointer finger.
[0049] During testing, a new test strip should be aligned with the
lancet to collect the sample. The patient can select the sensor
cartridge actuator to rotate the sensor cartridge to a new test
strip so that the corresponding capillary is aligned with the
lancet in the test passage 76. Once aligned, the patient can
squeeze the outer grip of the housing to impede venous return of
the test finger, as described above with reference to FIG. 6.
Thereafter, the patient can select the test actuator, which deploys
the lancet to impale the skin of the engorged fingertip in
precisely the correct location to form a sample blood droplet at
the entrance to the capillary. The creation of fingertip
engorgement or milking may be further improved by sequentially
squeezing the test finger from proximal to distal using a manual
mechanism.
[0050] The blood sample is collected on the test strip aligned with
the lancet. FIG. 7B is a block diagram 80 showing, by way of
example, entry of a sample 85 into an blood glucose sampling device
81. A test strip 83 is aligned with a lancet 84 in the test
passage. The alignment ensures that the sample obtained is located
at the entrance of a capillary 85 in the test strip 83. A test
finger 82 of a patient contacts the test strip 83 by entering the
housing when positioned over the opening of the test passage. In a
further embodiment, the test strip can extend out of the housing to
ensure contact with the test finger. A sample drop of blood 85
forms on the test fingertip 82 after the lancet 84 has been removed
and enters the blood glucose sampling device through a capillary 86
formed in the test strip 83. The blood 85 travels the distance of
the capillary 83 to a test region (not shown) having enzyme
electrodes, which analyzes the blood 85 to determine a
concentration level of glucose present.
[0051] Immediately after an adequate amount of blood enters the
capillary, a cleaning element contacts the test finger. FIG. 8 is a
block diagram 90 showing, by way of example, rotation of a cleaning
element 94 to an impalement site 95 on a test finger 92. Once the
sample has entered a capillary 96 formed in a test strip 93 of a
blood glucose sampling device 91, a sensor cartridge 97 can rotate
to align a cleaning element 94 with the impalement site 95 on the
test finger 92. The cleaning element 94 can absorb any blood 96
remaining on the test finger 92 so that the test finger is clean
once removed from the blood glucose sampling device. The rotation
of the sensor cartridge 97 can be activated upon a release of a
sensor cartridge actuator by a patient.
[0052] As described above with reference to FIG. 7A, the patient
selects the sensor cartridge actuator to first rotate the sensor
cartridge so that the test strip 93 is aligned with a lancet (not
shown) in a test passage prior to or upon impalement. Release of
the sensor cartridge actuator again rotates the sensor cartridge in
the same direction as the first rotation to align the cleaning
element in the test passage after impalement. Other mechanisms for
rotating the cleaning element on the sensor cartridge are possible,
including selecting a actuator, twisting a housing of the blood
glucose sampling device, and rotating a knob.
[0053] The obtained sample is analyzed and results are determined.
FIG. 9 is a block diagram 100 showing a hand 102 holding the blood
glucose sampling device 101 of FIG. 2, which displays results of a
sample. The blood glucose sampling device 101 includes a display
103, which can be affixed to a front side to allow visibility by a
patient holding the device 101. Other positions of the display on
the blood glucose sampling device are possible. The display
provides a reading of the sampling results, including a level of
glucose in the patient's blood. Other information can be presented
within the display, such as a time and date. The displayed results
can be recorded and stored on the blood glucose sampling device, or
alternatively, discarded.
[0054] A further embodiment includes a device mounted on a band,
which is worn on an extremity of the body, such as the forearm or
calf, to discreetly obtain and analyze samples, as well as to
prevent loss of the device. FIG. 10 shows front view of a mountable
blood glucose sampling device 110. A housing 115 of the mountable
blood glucose sampling device is affixed to a mounting device 111
to removably attach to an extremity 112 of a patient. The housing
115 can be made from plastic or metal; however, other materials are
possible. An example of the mounting device 111 can include a band,
which wraps around the patient's extremity 112, such as a wrist or
ankle. Other types of mounting devices, including a strap, belt, or
cuff are possible. A front of the mountable blood glucose sampling
device 110 can include a display 113 to present information.
Additionally, actuators 114, such as buttons, switches, or toggles,
can be positioned around a circumference of the mountable glucose
sampling device 110 to initiate action performed by the device.
[0055] The housing 115 of the mounted blood glucose sampling device
110 conformably encloses a sensor cartridge and lancet. FIG. 11 is
a cross-sectional view 120 of the mountable blood glucose sampling
device 130 of FIG. 10. A housing 121 of the mountable blood glucose
sampling device 130 conformably encloses a sensor cartridge 122,
test member 124, and lancet 125. A test passage opening 128 is
formed on a back side of the mountable device 130 and positioned to
contact a patient extremity 127. The test passage opening 128
provides a passage in which the lancet 125 is aligned. The sensor
cartridge 122 includes a plurality of blades oriented in a common
direction of rotation about a central point. Each blade includes a
test strip and a cleaning element. The test strip includes a test
region with enzyme electrodes that is defined radially from the
central point at a proximal end. A capillary is defined inwardly
from an outer edge of the test strip and terminates at a distal end
of the test region. The cleaning element is positioned adjacent to
the test strip in the common direction of rotation about the
central point. The blades are positioned so that the test strip of
one blad contacts the cleaning element of another blade.
[0056] The sensor cartridge 122 also includes a mount opening that
is formed at the central point or off-center. The mount opening is
shaped to receive a shaft 129 affixed to an inside of the housing
121. Once positioned, the sensor cartridge 122 can rotatably move
to align an outer tip of a clean test strip over the test passage
opening 128 for obtaining a blood sample 132 and to align an unused
cleaning element over the test passage opening 128 for removing any
excess blood. The test member 124 is pivotally positioned above the
test strip or cleaning element aligned over the test passage
opening 128 and can include a lever. The test member 124 is
attached to the housing 121 via a pivotable attachment mechanism
131, which can include a fulcrum. In a rest position, the test
member 124 is substantially parallel to the aligned test strip or
cleaning element. When selected via an actuator, a proximal end of
the test member pivots down toward a tip of the aligned test strip
or cleaning element, and exert pressure on the tip so that contact
is made with the sample 132 once obtained via the lancet 125. The
lancet 125 can be directly affixed to the housing 121 via a bolt,
joint or lock, or attached to a mount 133 that is affixed to the
housing 121. Other means and fasteners for affixing the lancet 135
to the housing 121 are possible. The lancet 125 is located along
the test passage at a substantially perpendicular angle to the
sensor cartridge 122 so that an outer edge of the blades in the
sensor cartridge 122 can contact the lancet 125. Other angles are
possible. The lancet 125 is spring-loadable or otherwise
slidably-oriented to facilitate lancing of the extremity 127
through the test passage opening 128.
[0057] The mountable blood glucose sampling device 130 also
includes a suction mechanism (not shown) for creating a suction
with a test site identified on the patient's extremity. The suction
mechanism can be located within the housing or can be affixed to
the back side of the housing. An internal suction mechanism can
include a pump, and an external suction mechanism can include a
suction cup. Other types of suction mechanisms are possible. The
suction can aid in the formation of a blood sample on the skin
surface of the test site. In one embodiment, a pushing force on the
mountable blood glucose sampling device 130 can cause air to be
expelled around the perimeter of the skin, which creates a seal.
The suction is then created by the recoil force of a spring within
the mountable blood glucose sampling device 130 to pull the skin of
the extremity towards the test passage opening 128. The suction
provides "milking" so that the extremity is engorged with blood and
prepared for impalement by the lancet 125, which is deployed to
pierce the skin of the engorged test site and retracted.
[0058] Upon lancing the skin, a blood sample is obtained. The
sample enters the capillary of the clean test strip aligned over
the test passage opening 128 and travels to the test region for
analysis. A determination is made whether the sample is large
enough for analysis. If not, additional blood must be obtained
through further "milking" of the test site. However, if
sufficiently large, the sample is analyzed to determine a blood
glucose concentration. After the sample is collected, the sensor
cartridge is rotated so the unused cleaning element is positioned
over the test passage opening 128 to remove any excess blood
remaining on the patient's extremity. The analysis and cleaning can
occur concurrently or sequentially.
[0059] The above-identified actions can be initiated by actuators
123, 126 formed within an outer circumference of the automated
sampling device housing 121. The actuators 123, 126 can include a
cartridge select, lancet deploy, lancet cock, suction, and mode
select actuators. The actuators 123, 126 can include a pushable
button, toggle, or switch, as well as other mechanisms. Selection
of the actuators 123, 126 initiates a specific action performed by
the mountable blood glucose sampling device 130.
[0060] In one example, the actuators 123, 126 are pushable buttons.
The cartridge select button can initiate rotation of the sensor
cartridge 122 upon depression so that the capillaries of the test
strip are positioned over the test passage opening 128, adjacent to
the lancet 125, while release initiates further rotation of the
sensor cartridge 122 to position a tip of the cleaning element over
the test passage opening 128. In a further embodiment, rotation of
the sensor cartridge 122 can be performed by multiple buttons or
actuators. The test button can initiate movement of the test member
for applying pressure on the test strip or cleaning element
positioned over the test passage 128. The test member 124 can be
moved via mechanical means or electrical means, which are initiated
by the test pressure button. In one embodiment, the test pressure
button is depressed inward, which applies an upward pressure on a
distal end of the test member 124 to pivot a proximal end, nearest
the lancet, down toward the tip of the test strip or cleaning
element. When fully pivoted, the proximal end of the test member
exerts a downward pressure on the test strip to the initiate
contact with the lancet 125 or on the cleaning element to initiate
contact with the sample 132.
[0061] The lancet cock button can be selected to cock the lancet
for deploying into the skin of the extremity, while the lancet
deploy button can deploy the lancet to impale the test site and
subsequently, retract the lancet. The suction button can generate
pressure necessary to create a suction between the mountable blood
glucose sampling device 130 and the skin of the extremity 137. The
mode button allows a patient to switch functioning and displays
provided by the mountable blood glucose sampling device 130. For
example, the mountable device 130 can also provide a time, date,
and temperature. Other device functions, actuators, and actuator
functions are possible.
[0062] While the invention has been particularly shown and
described as referenced to the embodiments thereof, those skilled
in the art will understand that the foregoing and other changes in
form and detail may be made therein without departing from the
spirit and scope.
* * * * *