U.S. patent application number 10/207758 was filed with the patent office on 2003-02-13 for mechanical mechanism for a blood glucose sensor dispensing instrument.
Invention is credited to Brown, Michael K., Micinski, Russell J., Whitson, Robert C..
Application Number | 20030032190 10/207758 |
Document ID | / |
Family ID | 23208327 |
Filed Date | 2003-02-13 |
United States Patent
Application |
20030032190 |
Kind Code |
A1 |
Brown, Michael K. ; et
al. |
February 13, 2003 |
Mechanical mechanism for a blood glucose sensor dispensing
instrument
Abstract
A sensor dispensing instrument adapted to handle a sensor pack
containing a plurality of sensors and to perform a test using one
of the sensors. The sensor dispensing instrument includes an outer
housing and a mechanical mechanism contained therein for rotating
the sensor pack and ejecting one of the sensors from the sensor
pack and through a sensor slot on the housing. The mechanical
mechanism of the sensor dispensing instrument is operated by first
moving a disk drive pusher in a first direction to rotate the
sensor pack, and then moving the disk drive pusher in a second
direction to eject a sensor from the sensor cavity and through the
sensor slot.
Inventors: |
Brown, Michael K.; (Elkhart,
IN) ; Micinski, Russell J.; (South Bend, IN) ;
Whitson, Robert C.; (Elkhart, IN) |
Correspondence
Address: |
Jerome L. Jeffers, Esq.
Bayer Corporation
P.O. Box 40
Elkhart
IN
46515-0040
US
|
Family ID: |
23208327 |
Appl. No.: |
10/207758 |
Filed: |
July 30, 2002 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60311759 |
Aug 13, 2001 |
|
|
|
Current U.S.
Class: |
436/46 ; 221/268;
221/31; 221/88; 422/400; 422/63; 422/64; 435/14; 436/43 |
Current CPC
Class: |
Y10T 436/11 20150115;
Y10T 436/112499 20150115; G01N 33/4875 20130101; G07F 11/54
20130101; Y10T 436/110833 20150115 |
Class at
Publication: |
436/46 ; 436/43;
422/61; 422/63; 422/64; 422/104; 221/31; 221/88; 221/268;
435/14 |
International
Class: |
G01N 035/00 |
Claims
1. A sensor dispensing instrument adapted to handle a sensor pack
containing a plurality of sensors, each of said plurality of
sensors being disposed in a sensor cavity on said sensor pack and
enclosed by a protective foil covering, said sensor dispensing
instrument further adapted to perform a test using one of said
plurality of sensors, and comprising: an outer housing having a
front end and a rear end, said outer housing further comprising a
sensor slot through which one of said sensors is disposed to
conduct the test, said sensor slot being disposed at the front end
of the outer housing; and a mechanical mechanism generally disposed
within the outer housing, said mechanical mechanism including an
indexing disk for supporting and rotating said sensor pack, an
indexing disk drive arm for rotating said indexing disk, a knife
blade assembly for puncturing said foil covering and ejecting one
of said sensors from said sensor cavity and through said sensor
slot, and a disk drive pusher on which said indexing disk drive arm
and said knife blade assembly are mounted, said disk drive pusher
being movable with respect to said outer housing, wherein said
sensor dispensing instrument is operated by first moving said disk
drive pusher in a first direction so as to cause said indexing disk
drive arm to rotate said indexing disk, and then moving said disk
drive pusher in a second direction so as to cause said knife blade
assembly to puncture the foil covering and eject one of said
sensors from said sensor cavity and through said sensor slot.
2. The sensor dispensing instrument according to claim 1, wherein a
puller handle is affixed to a rear end of the disk drive pusher,
and further wherein said puller handle is moved from a testing
position adjacent to the rear end of the outer housing to and
extended position spaced away from the rear end of the housing when
the disk drive pusher is moved in the first direction, and is move
from the extended position to the testing position when the disk
drive pusher is moved in the second direction.
3. The sensor dispensing instrument according to claim 2, wherein
the puller handle is moveable to a stand-by position, said stand-by
position being located between the testing position and the
extended position, wherein the puller handle is moved to the
stand-by position to release the sensor from the sensor slot.
4. The sensor dispensing instrument according to claim 1, wherein
the indexing disk comprises a plurality of curvilinearly extending
grooves and a plurality of radially extending grooves, each of said
radially extending grooves being disposed between an adjacent pair
of curvilinearly extending grooves, each of said curvilinearly
extending grooves having an interior end that is coincident with an
interior end of an adjacent radially extending groove disposed on a
first side thereof, and each of said curvilinearly extending
grooves having an exterior end that is coincident with an exterior
end of an adjacent radially extending groove disposed on a second
side thereof, further wherein said curvilinearly extending grooves
and said radially extending grooves are configured to be engaged by
said indexing disk drive arm.
5. The sensor dispensing instrument according to claim 4, wherein
said indexing disk drive arm comprises a cam button configured to
slide along said curvilinearly extending grooves and said radially
extending grooves as said disk drive pusher is moved, further
wherein said cam button slides along one of said curvilinearly
extending grooves when said disk drive pusher is moved in said
first direction, and said cam button slides along one of said
radially extending grooves when said disk drive pusher is moved in
said second direction.
6. The sensor dispensing instrument according to claim 5, wherein
the interior end of each of said curvilinearly extending grooves
that is coincident with the interior end of the adjacent radially
extending groove disposed on the first side thereof comprises an
interior step for directing said cam button into said curvilinearly
extending groove, and further wherein the exterior end of each of
said curvilinearly extending grooves that is coincident with the
exterior end of the adjacent radially extending groove disposed on
a second side thereof comprises an exterior step for directing said
cam button into said radially extending groove.
7. The sensor dispensing instrument according to claim 1, wherein
the indexing disk comprises plurality of slots that are configured
to permit a knife blade on said knife blade assembly to project
through one of said slots to puncture the foil covering and eject
one of said sensors from said sensor cavity and through said sensor
slot.
8. The sensor dispensing instrument according to claim 1, wherein
the indexing disk comprises a plurality of outwardly projecting
pins that are adapted to engage a plurality of notches on a
perimeter of the sensor pack when said sensor pack is disposed on
said indexing disk, said pins being configured so as to align said
sensor pack with said indexing disk and to cause said sensor pack
to rotate with the rotation of the indexing disk.
9. The sensor dispensing instrument according to claim 1, wherein
said knife blade assembly comprises a swing arm having a first end
and a second end, said first end being pivotally connected to the
disk drive pusher, said second end comprising a knife blade and a
cam follower, said cam follower being configured to follow a cam
pathway as the disk drive pusher is moved.
10. The sensor dispensing instrument according to claim 9, wherein
said cam pathway is configured to guide said cam follower so that
said knife blade is in a retracted position when said disk drive
pusher is moved in the first direction, and said knife blade is in
an extended position when said disk drive pusher is moved in the
second direction, further wherein said knife blade is in the
retracted position to permit the rotation of said indexing disk,
and said knife blade is in the extended position to permit said
knife blade to puncture the foil covering and eject one of said
sensors from said sensor cavity and through said sensor slot.
11. The sensor dispensing instrument according to claim 9, wherein
said knife blade assembly further comprises a second cam follower
disposed on the second end, said second cam follower being guided
by a cam spring so that said cam follower travels the cam pathway
in only one direction.
12. The sensor dispensing instrument according to claim 1, further
comprising an electronics assembly for performing the test and
displaying test results, said electronics assembly comprising a
printed circuit board, electrical components mounted on the printed
circuit board for conducting electronic functions in response to
electrical signals, at least one button mounted on the printed
circuit board for supplying electrical signals to the electrical
components, and a liquid crystal display mounted on the printed
circuit board for displaying said test results.
13. The sensor dispensing instrument according to claim 12, wherein
the electronics assembly further comprises a communication
interface mounted on the printed circuit board for connecting the
sensor dispensing instrument to a separate electronic device.
14. The sensor dispensing instrument according to claim 12, wherein
the electronics assembly further comprises battery terminals
mounted on the printed circuit board for connecting to a battery,
said battery for supplying electrical power to said electrical
components.
15. The sensor dispensing instrument according to claim 12, wherein
said electronics assembly is electrically connected to a sensor
actuator disposed adjacent to said sensor slot, said sensor
actuator being adapted to connect to contacts on a sensor disposed
in said sensor slot and transmit electrical signals between said
sensor and said printed circuit board.
16. The sensor dispensing instrument according to claim 15, wherein
the sensor actuator is engaged by said disk drive pusher to connect
to the contacts on the sensor disposed in said sensor slot.
17. A sensor dispensing instrument adapted to perform a test by
using a fluid testing sensor, said fluid testing sensor being
supplied by a disposable sensor pack inserted into said sensor
dispensing instrument, said sensor pack having a plurality of
sensor cavities covered by a protective foil, said fluid testing
sensor being enclosed in one said sensor cavities prior to the
performance of said test, said sensor dispensing instrument
comprising: an outer housing having a front end and a rear end,
said outer housing further comprising an upper case and a lower
case, said upper case and said lower case being pivotally connected
together near the rear end of the outer housing in a clam-like
fashion to permit the outer housing to be opened to permit the
insertion of the sensor pack; a latch disposed near the front end
of the outer housing and adapted to connect the upper case to the
lower case so as to close said outer housing after the insertion of
said sensor pack; a sensor slot disposed at the front end of the
outer housing, said sensor slot being adapted to receive said fluid
testing sensor, said fluid testing sensor projecting outwardly
through said sensor slot during the performance of said test; an
indexing disk for supporting and rotating said sensor pack, said
indexing disk being rotatably mounted within said outer housing and
comprising a first surface and a second surface, said first surface
being configured to align and support said sensor pack, said second
surface comprising a plurality of curvilinearly extending grooves
and a plurality of radially extending grooves, each radially
extending groove being disposed between an adjacent pair of
curvilinearly extending grooves, said indexing disk further
comprising a plurality of knife slots, each knife slot passing from
the first surface to the second surface and aligned with one of the
plurality of radially extending grooves; a disk drive pusher
generally disposed within said outer housing for rotating the
indexing disk and ejecting the fluid testing sensor from said
sensor pack, said disk drive pusher being laterally movable and
comprising an indexing disk drive arm for rotating said indexing
disk, said indexing disk drive arm having a cam button that is
adapted to engage one of the curvilinearly extending grooves and
the radially extending grooves, said disk drive pusher further
comprising a knife blade assembly for ejecting the fluid testing
sensor from the sensor pack, said knife blade assembly comprising a
cam follower adapted to extend a knife blade through one of the
knife slots in the indexing disk, said knife blade being adapted to
puncture said protective foil and engage the fluid testing sensor
so as to eject said fluid testing sensor from said sensor cavity
and through said sensor slot when in the extended position; a
puller handle generally disposed at the rear end the outer housing
for moving said dish drive pusher, said puller handle being affixed
to a rear end of the disk drive pusher, said puller handle being
moveable between a testing position adjacent to the rear end of the
outer housing and an extended position spaced outwardly from the
rear end of the outer housing; an electronics assembly for
performing the test and displaying test results, said electronics
assembly comprising a printed circuit board, electrical components
mounted on the printed circuit board for conducting electronic
functions in response to electrical signals, a plurality of buttons
mounted on the printed circuit board for supplying electrical
signals to the electrical components, a liquid crystal display
mounted on the printed circuit board for displaying said test
results, battery terminals mounted on said printed circuit board
for connecting to a battery to supply electrical power to said
electronics assembly; and a sensor actuator disposed within said
outer housing adjacent to said sensor slot for connecting the fluid
testing sensor to the electronics assembly, said sensor actuator
having metal contacts adapted to connect to contacts on the fluid
testing sensor when said fluid sensor testing sensor is disposed in
said sensor slot so as to transmit electrical signals between said
fluid testing sensor and the printed circuit board of said
electronics assembly, said sensor actuator being engaged by a front
end of said disk drive pusher when said puller handle is in the
testing position, wherein said sensor dispensing instrument is
operated by first pulling said puller handle from the testing
position to the extended position so as to cause said indexing disk
drive arm to travel along one of the curvilinearly extending
grooves to rotate said indexing disk and align the sensor cavity
containing the fluid testing sensor with the sensor slot, and then
pushing said puller handle from the extended position to the
testing position so as to cause said knife blade to extend through
one of the knife slots in the indexing disk to puncture the foil
covering and eject the fluid testing sensor from the sensor cavity
and through said sensor slot.
18. The sensor dispensing instrument according to claim 17, wherein
the metal contacts of said sensor actuator are connected to the
contacts on said fluid testing sensor when said puller handle is in
the testing position.
19. The sensor dispensing instrument according to claim 18, wherein
the puller handle is moveable to a stand-by position, said stand-by
position being located between the testing position and the
extended position, wherein the metal contacts of said sensor
actuator are disconnected from the contacts on said fluid testing
sensor when said puller handle is moved from the testing position
to the stand-by position.
20. The sensor dispensing instrument according to claim 19, wherein
the sensor dispensing instrument further comprises a sensor release
disposed on the outer housing, said sensor release being configured
to engage the front end of the disk drive pusher when the puller
handle is in the testing position, further wherein said sensor
release is engaged to move the puller handle from the testing
position to the stand-by position.
21. The sensor dispensing instrument according to claim 20, wherein
the sensor release comprises a sensor release button that projects
outwardly from the upper case, and said sensor release button is
depressed to move the puller handle from the testing position to
the stand-by position.
22. The sensor dispensing instrument according to claim 17, wherein
the plurality of curvilinearly extending grooves and the plurality
of radially extending grooves are interconnected so as to form a
continuous pathway along which said cam button travels via the
movement of the disk drive pusher, each of said curvilinearly
extending grooves comprising an interior end that is coincident
with an interior end of an adjacent radially extending groove
disposed on a first side thereof, and each of said curvilinearly
extending grooves further comprising an exterior end that is
coincident with an exterior end of an adjacent radially extending
groove disposed on a second side thereof.
23. The sensor dispensing instrument according to claim 22, wherein
the interior end of each of said curvilinearly extending grooves
that is coincident with the interior end of the adjacent radially
extending groove disposed on the first side thereof comprises an
interior step for directing said cam button into said curvilinearly
extending groove, and further wherein the exterior end of each of
said curvilinearly extending grooves that is coincident with the
exterior end of the adjacent radially extending groove disposed on
a second side thereof comprises an exterior step for directing said
cam button into said radially extending groove.
24. The sensor dispensing instrument according to claim 17, wherein
the indexing disk comprises a plurality of outwardly projecting
pins that are adapted to engage a plurality of notches on a
perimeter of the sensor pack when said sensor pack is disposed on
said indexing disk, said pins being configured so as to align said
sensor pack with said indexing disk and to cause said sensor pack
to rotate with the rotation of the indexing disk.
25. The sensor dispensing instrument according to claim 17, wherein
the electronics assembly further comprises a communication
interface mounted on the printed circuit board for connecting the
sensor dispensing instrument to a separate electronic device.
26. A method of operating a sensor dispensing instrument adapted to
handle a sensor pack containing a plurality of sensors, each of
said plurality of sensors being disposed in a sensor cavity on said
sensor pack and enclosed by a protective foil covering, said sensor
dispensing instrument further adapted to perform a test using one
of said plurality of sensors, said sensor dispensing instrument
comprising an outer housing having a sensor slot through which one
of said sensors is disposed to conduct the test, and said sensor
dispensing instrument further comprising a mechanical mechanism
having an indexing disk for supporting and rotating said sensor
pack, an indexing disk drive arm for rotating said indexing disk, a
knife blade assembly for puncturing said foil covering and ejecting
one of said sensors from said sensor cavity and through said sensor
slot, and a puller handle for moving said indexing disk drive arm
and said knife blade assembly, wherein said method comprises the
steps of: a) pulling said puller handle away from said outer
housing to cause said indexing disk drive arm to rotate said
indexing disk and align the sensor cavity with the sensor slot; b)
pushing said puller handle towards said outer housing to cause said
knife blade assembly to puncture the foil covering and eject the
sensor from the sensor cavity and through said sensor slot; and c)
performing the test by using the sensor disposed in said sensor
slot.
27. The method of operating a sensor dispensing instrument
according to claim 26, further comprising the steps of: e) viewing
test results generated by the test on a liquid crystal display
disposed on the outer housing; and f) removing the sensor from the
sensor slot.
28. The method of operating a sensor dispensing instrument
according to claim 27, wherein the step of removing the sensor from
the sensor slot is accomplished by moving the puller handle from
the testing position to a stand-by position, said stand-by position
being located between the testing position and the extended
position.
29. A method of operating a sensor dispensing instrument adapted to
handle a sensor pack containing a plurality of sensors, each of
said plurality of sensors being disposed in a sensor cavity on said
sensor pack and enclosed by a protective foil covering, said sensor
dispensing instrument further adapted to perform a test using one
of said plurality of sensors, said sensor dispensing instrument
comprising an outer housing having a sensor slot disposed at a
front end of the outer housing through which one of said sensors is
disposed to conduct the test, and said sensor dispensing instrument
further comprising a mechanical mechanism having an indexing disk
for supporting and rotating said sensor pack, a movable disk drive
pusher, an indexing disk drive arm mounted on the disk drive pusher
for rotating said indexing disk, a knife blade assembly mounted on
the disk drive pusher for puncturing said foil covering and
ejecting one of said sensors from said sensor cavity and through
said sensor slot, and a puller handle affixed to an end of the disk
drive pusher for moving said disk drive pusher, said puller handle
being moveable between a testing position adjacent to a rear end of
the outer housing, an extended position spaced outwardly from the
rear end of the outer housing, and a stand-by position located
between the testing position and the extended position, wherein
said method comprises the steps of: a) opening said outer housing
and placing a sensor pack on the indexing disk, said sensor pack
being placed on said indexing disk by engaging notches in a
perimeter of the sensor pack with pins on the indexing disk; b)
closing the outer housing; c) grasping said puller handle between a
finger and a thumb of a user hand when said puller handle is in the
stand-by position; d) pulling said puller handle from the stand-by
position to the extended position so as to move said disk drive
pusher and cause said indexing disk drive arm to rotate said
indexing disk, said indexing disk being rotated by the movement of
a cam button on the indexing disk drive arm along a curvilinearly
extending groove disposed on said indexing disk; e) pushing said
puller handle from the extended position to the testing position so
as to move said disk drive pusher and cause said knife blade
assembly to puncture the foil covering, engage the sensor in the
sensor cavity, eject the sensor from said sensor cavity, and push
said sensor through the sensor slot, said sensor being engaged by a
knife blade on the knife blade assembly that is extended through a
knife slot in the indexing disk by a cam follower on the knife bade
assembly; f) performing the test by using the sensor disposed in
said sensor slot; g) viewing test results generated by the test on
a liquid crystal display disposed on the outer housing; and f)
moving said puller handle from the testing position to the standby
position so as to cause the sensor to be released from the sensor
slot.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to a fluid
monitoring system, and, more particularly, to a new and improved
instrument for handling multiple sensors that are used in analyzing
blood glucose or other analytes contained therein.
[0003] 2. Description of the Prior Art
[0004] People suffering from various forms of diabetes routinely
need to test their blood to determine the level of blood glucose.
The results of such tests can be used to determine what, if any,
insulin or other medication needs to be administered. In one type
of blood glucose testing system, sensors are used to test a sample
of blood.
[0005] Such a sensor may have a generally flat, rectangular shape
with a front or testing end and a rear or contact end. The sensor
contains biosensing or reagent material that will react with blood
glucose. The testing end of the sensor is adapted to be placed into
the fluid being tested, for example, blood that has accumulated on
a person's finger after the finger has been pricked. The fluid is
drawn into a capillary channel that extends in the sensor from the
testing end to the reagent material by capillary action so that a
sufficient amount of fluid to be tested is drawn into the sensor.
The fluid then chemically reacts with the reagent material in the
sensor with the result that an electrical signal indicative of the
blood glucose level in the blood being tested is supplied to
contact areas located near the rear or contact end of the
sensor.
[0006] In order to couple the electrical signals produced at the
sensor contacts to monitoring equipment, the sensors need to be
inserted into sensor holders prior to the sensor end being placed
into the fluid being tested. The holders have corresponding mating
contact areas that become coupled to the contacts on the sensor
when the sensor is inserted into the holder. Consequently, the
holders act as an interface between the sensor and monitoring
equipment that accumulates and/or analyzes the test results.
[0007] Prior to being used, the sensors need to be maintained at an
appropriate humidity level so as to insure the integrity of the
reagent materials in the sensor. Sensors can be packaged
individually in tear-away packages so that they can be maintained
at the proper humidity level. For instance, blister type packaging
methods could be used. In this connection, the packages can include
desiccant material to maintain the proper humidity in the package.
In order for a person to use an individual sensor for testing blood
glucose, the package must be opened by tearing the seal.
Alternatively, some packages require the user to exert force
against one side of the package resulting in the sensor bursting or
rupturing the foil on the other side. As can be appreciated, the
opening of these packages can be difficult. Moreover, once the
package is opened, the user needs to be sure that the sensor is not
damaged or contaminated as it is being placed into the sensor
holder and used to test the blood sample.
[0008] U.S. Pat. No. 5,610,986, issued on May 20, 1997, and
entitled Dispensing Instrument For Fluid Monitoring Sensors
(referred to hereinafter as "the '986 patent"), discloses a type of
sensor pack with multiple sensors and a testing blood glucose and
dispensing instrument for handling the sensors contained in such a
sensor pack. In particular, the sensor dispensing instrument
disclosed in the 986 patent is adapted to receive a sensor pack
containing a plurality of blood glucose sensors. The sensor pack
includes a circular base having a plurality of sensor retaining
cavities, each of which hold an individual sensor. Each of the
sensors has a generally flat, rectangular shape with a front
testing end through which fluid is drawn so as to react with a
reagent material in the sensor and an opposite rear, contact
end.
[0009] The sensor instrument disclosed in the '986 patent includes
an outer housing having an upper and a lower case that are
pivotable with respect to each other so that the sensor pack can be
positioned in the housing on an indexing disk disposed in the
housing. With the sensor pack loaded in the housing, a slide latch
on a slide actuator disposed on the upper case of the housing
controls whether the movement of the slide actuator places the
instrument in a display mode or in a testing mode. The instrument
is placed into its display mode when the slide latch is moved
laterally and the slide actuator is pushed away from its standby
position. When in the display mode, a person using the instrument
can view data displayed on a display unit in the upper case and/or
input data into the instrument.
[0010] The instrument is in its testing mode when the slide latch
is in its normal position and the slide actuator is pushed towards
its testing position. As the slide actuator is moved towards its
actuated position, the driver with the knife blade thereon moves
toward the testing position of the feed mechanism and the disk
drive arm travels in a straight, radially extending groove in the
indexing disk such that the disk is not rotated as the feeding
mechanism is moving towards its testing position. The knife blade
is moved towards one of the sensor cavities in the sensor pack and
pierces the foil covering the sensor cavity so as to engage the
sensor disposed in the cavity. As the slide actuator and the driver
are pushed toward the actuated position of the actuator, the knife
blade ejects the sensor out from the sensor cavity and into a
testing position near the testing end of the sensor housing.
[0011] Once the blood analyzing test is completed, the slide
actuator is moved in the opposite direction towards its standby
position so that the sensor can be removed from the dispensing
instrument. The continued retraction of the driver causes the
indexing disk drive arm to travel along a curvilinearly extending
groove in the indexing disk, resulting in the rotation of the
indexing disk. The rotation of the indexing disk results in the
sensor pack being rotated so that the next sensor is positioned in
alignment with the knife blade for the next blood glucose test that
is to be performed.
[0012] Although the sensor instrument disclosed in the '986 patent
overcomes many of the problems discussed above in connection with
the use of individual sensors, some users of have experienced
difficulties in the operation and/or manipulation of the disclosed
sensor instrument. For example, users with limited dexterity may
find the manipulation of the slide latch difficult. Similarly, some
users, elderly users in particular, may find the operation of this
device complicated or confusing. This may lead to user errors in
the manipulation of the slide latch, which can result in a jam in
the operation of the device. Accordingly, it is desirable to have a
sensor dispensing instrument utilizing an improved mechanical
mechanism that can be more easily manipulated by users with limited
dexterity, and is less likely to jam as the result of user
error.
[0013] In addition, some users have encountered spoiled sensors
resulting from partial or incorrect manipulation of the device.
This is because a new sensor is moved into alignment with the knife
blade at the conclusion of each test. If, for example, a user
intending to activate the display mode of the device accidentally
moves the slide latch into the testing mode direction, the knife
blade may puncture the foil covering the sensor cavity of the new
sensor. Even if the user realizes the error and returns the slide
latch to the neutral position, the sensor in the punctured sensor
cavity will be exposed to the air and must be used immediately or
discarded. Accordingly, it is desirable to have a sensor dispensing
instrument utilizing an improved mechanical mechanism that will
eliminate inadvertent spoilage of sensors as the result of user
error.
BRIEF SUMMARY OF THE INVENTION
[0014] Accordingly, an object of the present invention is to
provide a new and improved sensor dispensing instrument for
handling the sensors contained in a sensor pack of multiple sensors
used in testing blood glucose. In particular, objects of the
present invention are to provide a new and improved fluid sensor
dispensing instrument handling device having a mechanical mechanism
that can be more easily operated by a user with limited finger
strength or dexterity, that reduces the possibility of jams,
eliminates the spoilage of sensors because of user error, and which
otherwise overcomes the problems or limitations discussed
above.
[0015] In accordance with these and many other objects of the
present invention, the present invention is embodied in a sensor
dispensing instrument that is adapted to handle a sensor pack
containing a plurality of sensors, each of the plurality of sensors
being disposed in a sensor cavity on the sensor pack and enclosed
by a protective foil covering. The sensor dispensing instrument is
further adapted to perform a test using one of the sensors. The
sensor dispensing instrument includes an outer housing having a
front end and a rear end, and a sensor slot at the front end of the
housing through which one of said sensors is disposed to conduct
the test. The sensor dispensing instrument also includes a
mechanical mechanism that has an indexing disk for supporting and
rotating the sensor pack, an indexing disk drive arm for rotating
the indexing disk, a knife blade assembly for puncturing the foil
covering and ejecting one of the sensors from the sensor cavity and
through the sensor slot, and a movable disk drive pusher on which
the indexing drive arm and the knife blade assembly are mounted.
The sensor dispensing instrument is operated by first moving the
disk drive pusher in a first direction to rotate the indexing disk,
and then moving the disk drive pusher in a second direction to
puncture the foil covering and eject one of the sensors from the
sensor cavity and through the sensor slot.
[0016] In the preferred embodiment, the sensor dispensing
instrument also includes a puller handle affixed to an end of the
disk drive pusher. The puller handle is moveable between a testing
position adjacent to the rear end of the outer housing and an
extended position spaced outwardly from the rear end of the outer
housing. Wherein the puller handle is moved from the testing
position to the extended position when the disk drive pusher is
moved in the first direction, and is moved from the extended
position to the testing position when the disk drive pusher is
moved in the second direction.
[0017] In accordance with another aspect of the present invention,
the present invention is embodied in a method of operating a sensor
dispensing instrument that is adapted to handle a sensor pack
containing a plurality of sensors and to perform a test using one
of the sensors, wherein the sensor dispensing instrument includes
an outer housing having a sensor slot through which one of the
sensors is disposed to conduct the test, a mechanical mechanism
having an indexing disk for supporting and rotating the sensor
pack, an indexing disk drive arm for rotating the indexing disk, a
knife blade assembly for puncturing the foil covering and ejecting
one of the sensors from the sensor cavity and through the sensor
slot, and a disk drive pusher for moving the indexing disk drive
arm and the knife blade assembly. The method comprises the steps
of: a) moving disk drive pusher in a first direction to cause the
indexing disk drive arm to rotate the indexing disk; b) moving the
disk drive pusher in a second direction to cause the knife blade
assembly to puncture the foil covering and eject one of the sensors
from the sensor cavity and through the sensor slot; and c)
performing the test by using the sensor disposed in the sensor
slot.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0018] The present invention, together with the above and other
objects and advantages, can best be understood from the following
detailed description of the embodiment of the invention illustrated
in the drawing, wherein:
[0019] FIG. 1 is a top perspective view of a blood glucose sensor
dispensing instrument embodying the present invention;
[0020] FIG. 2 is a bottom perspective view of the blood glucose
sensor dispensing instrument of FIG. 1;
[0021] FIG. 3 is a perspective view of the blood glucose sensor
dispensing instrument of FIG. 1 in the opened position showing the
insertion of a sensor pack;
[0022] FIG. 4 is a perspective view of the blood glucose sensor
dispensing instrument of FIG. 1 in the opened position showing a
sensor pack loaded onto the indexing disk;
[0023] FIG. 5 is a top perspective view of the blood glucose sensor
dispensing instrument of FIG. 1 shown with the button door in the
open position;
[0024] FIG. 6 is a top perspective view of the blood glucose sensor
dispensing instrument of FIG. 1 with the disk drive pusher in the
extended position;
[0025] FIG. 7 is a top perspective view of the blood glucose sensor
dispensing instrument of FIG. 1 with the disk drive pusher in the
testing position with a sensor projecting from the sensor
opening;
[0026] FIG. 8 is a top perspective view of a sensor for use with
blood glucose sensor dispensing instrument of FIG. 1;
[0027] FIG. 9 is an exploded perspective view of a sensor pack for
use with blood glucose sensor dispensing instrument of FIG. 1
showing the protective foil separated from the base portion of the
sensor pack;
[0028] FIG. 10 is an exploded perspective view of the component
subassemblies of blood glucose sensor dispensing instrument of FIG.
1;
[0029] FIG. 11 is an exploded perspective view of the component
parts of the upper case sub-assembly of the blood glucose sensor
dispensing instrument of FIG. 1;
[0030] FIG. 12 is an exploded perspective view of the component
parts of the lower case sub-assembly of the blood glucose sensor
dispensing instrument of FIG. 1;
[0031] FIG. 13 is an exploded top perspective view of the component
parts of the disk drive mechanism and indexing disk sub-assembly of
the blood glucose sensor dispensing instrument of FIG. 1;
[0032] FIG. 14 is an exploded bottom perspective view of the
component parts of the disk drive mechanism and indexing disk
sub-assembly of the blood glucose sensor dispensing instrument of
FIG. 1;
[0033] FIG. 15 is an exploded perspective view of the component
parts of the battery tray sub-assembly of the blood glucose sensor
dispensing instrument of FIG. 1;
[0034] FIG. 16 is an exploded perspective view of the component
parts of the electronics assembly of the blood glucose sensor
dispensing instrument of FIG. 1;
[0035] FIG. 17 is a top perspective view of the electronics
sub-assembly of the blood glucose sensor dispensing instrument of
FIG. 1; and
[0036] FIG. 18 is a bottom perspective view of the electronics
sub-assembly of the blood glucose sensor dispensing instrument of
FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0037] Referring now more specifically to the drawings, therein is
disclosed a blood glucose sensor dispensing instrument generally
designated by the reference numeral 10 and embodying the present
invention. The sensor dispensing instrument 10 includes an outer
housing 12 having an upper case 18 and a lower case 24, the lower
case 24 pivoting on the upper case 18. The upper case 18 is
pivotable with respect to the lower case 24 in a clamshell fashion
so that a sensor pack 300 (see FIGS. 3 and 4) can be positioned on
an indexing disk 30 within the housing 12. With the sensor pack 300
so loaded in the housing 12, a puller handle 32 extending from a
rear end 22 of the upper case 18 of the housing 12 can be moved to
activate a disk drive mechanism, generally designated by the
numeral 34 (see FIG. 10), to load a sensor 302 into a testing
position on the front end 14 of the housing 12 (see FIG. 3).
[0038] It should be noted that the sensor dispensing instrument 10
of the present invention incorporates components that are similar
in design and/or function as those described in U.S. Pat. No.
5,630,986, issued May 20, 1997, and entitled Dispensing Instrument
For Fluid Monitoring Sensors. The contents of this patent are
hereby incorporated by reference to avoid the unnecessary
duplication of the description of these similar components.
[0039] The sensor pack 300 utilized by the sensor dispensing
instrument 10 is of the type described in U.S. Pat. No. 5,575,403,
issued Nov. 19, 1996, and entitled Dispensing Instrument For Fluid
Monitoring Sensors, the contents of which are hereby incorporated
by reference. In general, and as shown in FIGS. 8 and 9, the sensor
pack 300 is adapted to house ten sensors 302, with one of the ten
sensors 302 in each of ten separate sensor cavities 304. Each of
the sensors 302 has a generally flat, rectangular shape extending
from a front or testing end 306 to a back end 308. The front end
306 is angled so that it will puncture an unsevered portion of the
protective foil 310 overlying the sensor cavity 304 as the sensor
302 is being forced out of the sensor cavity 304 by a knife blade
36 (to be described below). The front end 306 is also adapted to be
placed into blood that is being analyzed. The back end 308 of the
sensor 302 includes a small notch 312 that is engaged by the knife
blade 36 as the knife blade 36 ejects the sensor 302 from the
sensor cavity 304. Contacts 314 near the back end 308 of the sensor
302 are adapted to mate with metal contacts 38 on a sensor actuator
40 (to be described below) when the sensor 302 is in the testing
position illustrated in FIG. 7. As a result, the sensor 302 is
coupled to the electronic circuitry on the circuit board assembly
42 so that information generated in the sensor 302 during
testing-can be stored, analyzed and/or displayed.
[0040] As best seen in FIG. 8, each sensor 302 is provided with a
capillary channel 316 that extends from the front or testing end
306 of the sensor 302 to biosensing or reagent material disposed in
the sensor 302. When the testing end 306 of the sensor 302 is
placed into fluid (for example, blood that is accumulated on a
person's finger after the finger has been pricked), a portion of
the fluid is drawn into the capillary channel 316 by capillary
action. The fluid then chemically reacts with the reagent material
in the sensor 302 so that an electrical signal indicative of the
blood glucose level in the blood being tested is supplied to the
contacts 314, and subsequently transmitted through the sensor
actuator 40 to the circuit board assembly 42.
[0041] As best seen in FIG. 9, the sensor pack 300 comprises a
circularly shaped base portion 318 covered by a sheet of protective
foil 310. The sensor cavities 304 are formed as depressions in the
base portion 318, with each of the sensor cavities 304 adapted to
house an individual sensor 302. Each of the sensor cavities 304 has
an inclined or sloped support wall 320 to guide the sensor 302 as
the sensor 302 is ejected through the foil 310 and out of the
sensor cavity 304.
[0042] Each of the sensor cavities 304 is in fluid communication
with a desiccant cavity 322 formed by a small depression in the
base portion 318. Desiccant material is disposed in each of the
desiccant cavities 322 in order to insure that the sensor cavities
304 are maintained at an appropriate humidity level to preserve the
reagent material in the sensor 302.
[0043] Notches 324 are formed along the outer peripheral edge of
the base portion 318. The notches 324 are configured to engage pins
44 on the indexing disk 30 so that the sensor cavities 304 are in
proper alignment with the indexing disk 30 when the sensor pack 300
is loaded into the sensor dispensing instrument 10. As will be
explained in greater detail below, the sensor cavities 304 must be
aligned with the knife slots 46 in the indexing disk 30 to permit
the knife blade 36 to engage, eject and push one of the sensors 302
into a testing position on the front end 14 of the housing 12.
[0044] The sensor pack 300 further comprises a conductive label 326
on the central portion of the base portion 318. As will be
explained below, the conductive label 326 provides calibration and
production information about the sensor pack 300 that can be sensed
by calibration circuitry in the sensor dispensing instrument
10.
[0045] To operate the sensor dispensing instrument 10, the puller
handle 32 is first manually pulled from a standby position (FIG. 1)
adjacent the rear end 16 of the housing 12 to an extended position
(FIG. 6) away from the rear end 16 of the housing 12. The outward
movement of the puller handle 32 causes the disk drive mechanism 34
to rotate the sensor pack 300 and place the next sensor 302 in a
standby position prior to being loaded into a testing position. The
outward movement of the puller handle 32 also causes the sensor
dispensing instrument 10 to turn ON (i.e., the electronic circuitry
on the circuit board assembly 42 is activated).
[0046] As will be described in greater detail below, the disk drive
mechanism 34 includes a disk drive pusher 48 on which an indexing
disk drive arm 50 is mounted (see FIGS. 13 and 14). The indexing
disk drive arm 50 comprises a cam button 52 disposed at the end of
a plate spring 54. The cam button 52 is configured to travel in one
of a plurality of curvilinearly extending grooves 56 on the upper
surface of the indexing disk 30. As the puller handle 32 is
manually pulled from a standby position adjacent the rear end 16 of
the housing 12 to an extended position away from the rear end 16 of
the housing 12, the disk drive pusher 48 is pulled laterally
towards the rear end 22 of the upper case 18. This causes the cam
button 52 on the indexing disk drive arm 50 to travel along one of
the curvilinearly extending grooves 56 so as to rotate the indexing
disk 30. The rotation of the indexing disk 30 causes the sensor
pack 300 to be rotated so that the next one of the sensor cavities
304 is placed in a standby position.
[0047] The puller handle 32 is then manually pushed inwardly from
the extended position (FIG. 6) back past the standby position (FIG.
1) and into a testing position (FIG. 7). The inward movement of the
puller handle 32 causes the disk drive mechanism 34 to remove a
sensor 302 from the sensor pack 300 and place the sensor 302 into a
testing position on the front end 14 of the housing 12.
[0048] As will be described in greater detail below, the disk drive
mechanism 34 includes a knife blade assembly 58 that is pivotally
mounted to the disk drive pusher 48 (see FIGS. 13 and 14). As the
puller handle 32 is manually pushed from the extended position to
the testing position, the disk drive pusher 48 is pushed laterally
towards the testing or front end 20 of the upper case 18. This
causes the knife blade assembly 58 to pivot downwardly so that a
knife blade 36 on the end of the knife blade assembly 58 pierces a
portion of the protective foil 310 covering one of the sensor
cavities 304 and engages the sensor 302 in the sensor cavity 304.
As the disk drive pusher 48 continues to move towards the front end
20 of the upper case 18, the knife blade assembly 58 forces the
sensor 302 out of the sensor cavity 304 and into a testing position
at the front end 14 of the housing 12.
[0049] While the disk drive pusher 48 is being pushed from the
extended position to the testing position, the cam button 52 on the
indexing disk drive arm 50 travels along one of the radially
extending grooves 60 to prevent the indexing disk 30 from rotating.
Similarly, while the disk drive pusher 48 is being pulled from the
standby position to the extended position, the knife blade assembly
58 is in a retracted position so as to not interfere with the
rotation of the indexing disk 30.
[0050] After the sensor 302 has been completely ejected from the
sensor cavity 304 and pushed into a testing position projecting out
from the front end 14 of the housing 12, the disk drive pusher 48
engages and forces a sensor actuator 40 against the sensor 302 to
thereby maintain the sensor 302 in the testing position. The sensor
actuator 40 engages the sensor 302 when the puller handle 32 is
pushed past the standby position and into the testing position. The
sensor actuator 40 couples the sensor 302 to an electronics
assembly 62 disposed in the upper case 18. The electronics assembly
62 includes a microprocessor or the like for processing and/or
storing data generated during the blood glucose test procedure, and
displaying the data on a liquid crystal display 64 in the sensor
dispensing instrument 10.
[0051] Once the blood analyzing test is completed, a button release
66 on the upper case 18 is depressed so as to disengage the sensor
actuator 40 and release the sensor 302. Depressing the button
release 66 causes the disk drive pusher 48 and the puller handle 32
to move from the testing position back to the standby position. At
this point, the user can turn the sensor dispensing instrument 10
OFF by depressing the button 96 on the upper case 18, or by
allowing the sensor dispensing instrument 10 automatically turn OFF
pursuant a timer on the electronics assembly 62.
[0052] As seen in FIGS. 1-7 and 10-12, the upper case 18 and the
lower case 24 of the sensor dispensing housing 12 are
complementary, generally oval shaped hollow containers that are
adapted to be pivoted with respect to each other about pivot pins
68 extending outwardly in the rear end 22 of the upper case 18 into
pivot holes 70 in a rear section 28 of the lower case 24. The upper
case 18 and the lower case 24 are maintained in their closed
configuration by a latch 72 that is pivotally mounted in a front
section 26 of the lower case 24 by pins 74 that extend inwardly
into pivot holes 76 in the latch 72 (see FIG. 12). The latch 72 has
recesses 78 that are configured to mate with hooks 80 on the upper
case 18 to secure the upper case 18 and the lower case 24 in their
closed configuration. The latch 72 is biased in a vertical or
closed position by a latch spring 82. The ends 84 of the latch
spring 82 are secured in slots 86 on the inside of the lower case
24. When the latch 72 is pivoted against the biasing force of the
latch spring 82, the hooks 80 on the upper case 18 disengage from
the recesses 78 to permit the upper case 18 and the lower case 24
to open.
[0053] As seen in FIGS. 1, 5-7 and 10-11, the upper case 18
includes a rectangular opening 30 through which a liquid crystal
display 64 is visible below. The liquid crystal display 64 is
visible through a display lens 88 that is affixed to upper surface
of the upper case 18. In the preferred embodiment shown, the
display lens 88 has an opaque portion 90 and a transparent portion
92, the transparent portion 92 being coincident with the display
area of liquid crystal display 64. The liquid crystal display 64 is
a component of the electronics assembly 62, and is coupled to the
circuit board assembly 42 via elastomeric connectors 94 (see FIG.
16). The liquid crystal display 64 displays information from the
testing procedure and/or in response to signals input by the
buttons 96 on the upper case 18. For example, the buttons 96 can be
depressed to recall and view the results of prior testing
procedures on the liquid crystal display 64. As best seen in FIG.
11, the buttons 96 are part of a button set 98 that is attached to
the upper case 18 from below so that the individual buttons 96
project upwardly through button openings 100 in the upper case 18.
When pressed, the buttons 96 are electrically connected to the
circuit board assembly 42.
[0054] As best seen in FIGS. 1, 5 and 11, a button door 102 is
pivotally connected to the upper case 18 by a pair of pins 104
projecting outwardly from either side of the button door 102 that
engage holes 106 on the side walls of the upper case 18. The button
door 102 also comprises a pair of ears 108 that fit into recesses
110 in the side walls of the upper case 18 when the button door 102
is closed. The ears 108 extend slightly beyond the side walls of
the upper case 18 so that they can be grasped by the user to open
the button door 102. A pivot edge 112 of the button door 102
engages a tab 114 on the upper surface of the upper case 18. The
tab 114 rubs against the pivot edge 112 in such a manner so as to
bias the button door 102 in either a closed or fully open position.
In the preferred embodiment shown, the button door 102 has an
opening 116 that permits one of the buttons 96 (e.g., an On/Off
button) to be accessed when the button door 102 is closed (see FIG.
1). This permits dedicated, but seldom or lesser used buttons 96 to
be concealed underneath the button door 102, thereby simplifying
the learning curve and daily operation of the sensor dispensing
instrument 10 for the user.
[0055] The upper case 18 also contains an opening 118 for the
button release 66, which projects upwardly through the upper case
18. As will be described in more detail below, the button release
66 is depressed to disengage the sensor actuator 40 and release a
sensor 302 from the testing position.
[0056] The upper case 18 also contains an opening 120 for a battery
tray assembly 122. The battery tray assembly 122 includes a battery
tray 124 in which a battery 126 is disposed. The batter tray
assembly 122 is inserted into the opening 120 in the side of the
upper case 18. When so inserted, the battery 126 engages battery
contacts 128 and 130 on the circuit board assembly 42 so as to
provide power for the electronics within the instrument 10,
including the circuitry on the circuit board assembly 42 and the
liquid crystal display 64. A tab 132 on the lower case 24 is
configured to engage a slot 134 in the battery tray assembly 122 so
as to prevent the battery tray assembly 122 from being removed from
the sensor dispensing instrument 10 when the upper case 18 and the
lower case 24 are in the closed configuration.
[0057] An electronics assembly 62 is affixed to the upper inside
surface of the upper case 18. As best seen in FIGS. 16-18, the
electronics assembly 62 comprises a circuit board assembly 42 on
which various electronics and electrical components are attached. A
positive battery contact 128 and a negative battery contact 130 are
disposed on the bottom surface 136 (which is the upwardly facing
surface as viewed in FIGS. 16 and 18) of the circuit board assembly
42. The battery contacts 128 and 130 are configure to electrically
connect with the battery 126 when the battery tray assembly 122 is
inserted into the side of the upper case 18. The bottom surface 136
of the circuit board assembly 42 also includes a communication
interface 138. The communication interface 138 permits the transfer
of testing or calibration information between the sensor dispensing
instrument 10 and another device, such as a personal computer,
through standard cable connectors (not shown). In the preferred
embodiment shown, the communication interface 138 is a standard
serial connector. However, the communication interface 138 could
alternatively be an infra-red emitter/detector port, a telephone
jack, or radio frequency transmitter/receiver port. Other
electronics and electrical devices, such as memory chips for
storing glucose test results or ROM chips for carrying out programs
are likewise included on the bottom surface 136 and the upper
surface 140 of the circuit board assembly 42.
[0058] A liquid crystal display 64 is affixed to the upper surface
140 (upwardly facing surface in FIG. 17) of the circuit board
assembly 42. The liquid crystal display 64 is held by a snap-in
display frame 142. The snap-in display frame 142 includes side
walls 144 that surround and position the liquid crystal display 64.
An overhang 146 on two of the side walls 144 holds the liquid
crystal display 64 in the snap-in display frame 142. The snap-in
display frame 142 includes a plurality of snap fasteners 148 that
are configured to engage mating holes 150 on the circuit board
assembly 42. The liquid crystal display 64 is electrically
connected to the electronics on the circuit board assembly 42 by a
pair of elastomeric connectors 94 disposed in slots 152 in the
snap-in display holder 142. The elastomeric connectors 94 generally
comprise alternating layers of flexible conductive and insulating
materials so as to create a somewhat flexible electrical connector.
In the preferred embodiment shown, the slots 152 contain a
plurality of slot bumps 154 that engage the sides of the
elastomeric connectors 94 to prevent them from falling out of the
slots 152 during assembly.
[0059] As set forth in detail in the U.S. Patent Application
entitle Snap-in Display Frame, which is being filed together with
the present application, the snap-in display frame 142 eliminates
the screw-type fasteners and metal compression frames that are
typically used to assemble and attach a liquid crystal display 64
to an electronic device. In addition, the snap-in display frame 142
also permits the liquid crystal display 64 to be tested prior to
assembling the liquid crystal display 64 to the circuit board
assembly 42.
[0060] The button set 98 also mates to the upper surface 140 of the
circuit board assembly 42. As mentioned above, the button set 98
comprises several individual buttons 96 that are depressed to
operate the electronics of the sensor dispensing instrument 10. For
example, the buttons 96 can be depressed to activate the testing
procedure of the sensor dispensing instrument 10. The buttons 96
can also be depressed to recall and have displayed on the liquid
crystal display 64 the results of prior testing procedures. The
buttons 96 can also be used to set and display date and time
information, and to activate reminder alarms which remind the user
to conduct a blood glucose test according to a predetermined
schedule. The buttons 96 can also be used to activate certain
calibration procedures for the sensor dispensing instrument 10.
[0061] The electronics assembly 62 further comprises a pair of
surface contacts 139 on the bottom surface 136 of the circuit board
assembly 42 (see FIGS. 16 and 18). The surface contacts 139 are
configured so as to be contacted by one or more fingers 143 on the
cover mechanism 188, which in turn are configured to be engaged by
a pair of ramp contacts 141 on the disk drive pusher 48 (see FIGS.
6 and 13). Movement of the puller handle 32 causes the ramp
contacts 141 to push the fingers 143 into contact with one or both
of the surface contacts 139 so as to communicate the position of
the puller handle 32 to the electronics assembly 62. In particular,
movement of the puller handle 32 from the stand-by or testing
positions to the extended position will turn the sensor dispensing
instrument ON. In addition, if the housing 12 is opened while the
puller handle 32 is in the extended position, an alarm will be
activated to warn the user that the knife blade 36 may be in the
extended position.
[0062] It should be noted that the design and configuration of the
electronics assembly 62 permits the assembly and testing of the
electronics and electrical components prior to assembly of the
electronics assembly 62 to the upper case 18 of the sensor
dispensing instrument 10. In particular, the liquid crystal display
64, the button set 98, the battery contacts 128 and 130, and the
other electronics and electrical components can each be assembled
to the circuit board assembly 42 and tested to verify that these
components, and the electrical connections to these components, are
working properly. Any problem or malfunction identified by the
testing can then be corrected, or the malfunctioning component can
be discarded, prior to assembling the electronics assembly 62 to
the upper case 18 of the sensor dispensing instrument 10.
[0063] As mentioned above, the sensor dispensing instrument 10
includes calibration circuitry for determining calibration and
production information about the sensor pack 300. As best seen in
FIG. 12, the calibration circuitry comprises a flex circuit 156
located in the lower case 24. The flex circuit 156 is held in
position in the lower case 24 by an autocal disk 158 that is
connected to the rear section 28 of the lower case 24 by a pair of
pins 160. The autocal disk 158 has a raised central portion 162
configured to engage the sensor cavities 304 on the sensor pack 300
so as to hold the sensor pack 300 against the indexing disk 30. The
autocal disk 158 also has an open area 164 located between the pins
160 to expose contacts 166 on the flex circuit 156.
[0064] The flex circuit 156 comprises a plurality of probes 168
that extend upwardly from the flex circuit 156 through holes 170 in
the inner region of the autocal disk 158. These probes 168 are
connected to the contacts 166 on the end of the flex circuit 156.
When the sensor dispensing instrument 10 is closed with the lower
case 24 latched to the upper case 18, the probes 168 make contact
with a conductive label 326 on the sensor pack 300 being used in
the sensor dispensing instrument 10. A foam pad 172 is positioned
below the flex circuit 156 to provide a biasing force to assure
that the probes 168 press against the conductive label 326 with a
force sufficient to make an electrical connection. The foam pad 172
also provides a cushioning force so that the probes 168 can move
independently with respect to each other as the sensor pack 300 is
being rotated by the indexing disk 30. As a result, information,
such as calibration and production data, contained on the
conductive label 326 can be transmitted via the probes 168 to the
flex circuit 156, which in turn couples the data to the electronic
circuitry on the circuit board assembly 42 via an elastomeric
connector 174. This information can then be used by the electronics
assembly 62 to calibrate the sensor dispensing instrument 10, or
can be displayed on the liquid crystal display 64.
[0065] As best seen in FIG. 10, the elastomeric connector 174 is
made of layers of silicon rubber extending from a top edge 176 to a
bottom edge 178 with alternate layers having conductive materials
dispersed therein to connect contacts on the top edge 176 to
contacts on the bottom edge 178. When the upper case 18 and the
lower case 24 are closed, the elastomeric connector 174 is
compressed in the direction between the edges 176 and 178 such that
the contacts along the top edge 176 engage electronic circuitry on
the circuit board assembly 42 in the upper case 18, and the
contacts along the bottom edge 178 engage the contacts 166 on the
flex circuit 156 in the lower case 24. With the elastomeric
connector 174 so compressed, low voltage signals can be readily
transmitted between the circuit board assembly 42 and the flex
circuit 156 through the elastomeric connector 174.
[0066] The elastomeric connector 174 is held in position by a
slotted housing 180 on the guide block 182. In the preferred
embodiment shown, the slotted housing 180 has a serpentine
cross-section configured to allow the connector 174 to compress
when the upper case 18 and the lower case 24 are closed, while
still holding the elastomeric connector 174 when the upper case 18
and the lower case 24 are open. Alternatively, the slotted housing
180 may include inwardly projecting ridges that engage the sides of
the connector 174.
[0067] The disk drive mechanism 34 is affixed to the upper inside
surface of the upper case 18. As best seen in FIG. 10, the disk
drive mechanism 34 is attached to the upper case by a plurality of
mounting screws 184 that engage posts (not shown) on the upper
inside surface of the upper case 18. The mounting screws 184 also
pass through and secure the electronics assembly 62, which is
disposed between the disk drive mechanism 34 and the upper case
18.
[0068] Although the disk drive mechanism 34 will be described in
greater detail below, it should be noted that the disk drive
mechanism 34 is configured so as to permit the assembly and testing
of its operation prior to mounting the disk drive mechanism 34 to
the upper inside surface of the upper case 18. In other words, the
disk drive mechanism 34 has a modular design that can be tested
prior to final assembly of the sensor dispensing instrument 10.
[0069] As best seen in FIGS. 13 and 14, the disk drive mechanism 34
comprises a guide block 182, a sensor actuator 40, a housing guide
186, a disk drive pusher 48, an indexing disk drive arm 50, a knife
blade assembly 58, a puller handle 32, a cover mechanism 188, and a
button release 66. The housing guide 186 is fixed to the upper
surface 190 (as viewed in FIG. 13) of the guide block 182 by one or
more pins 192. The disk drive pusher 48 is supported on the housing
guide 186 and the guide block 182 in such a manner as to permit the
disk drive pusher 48 to slide laterally relative to the housing
guide 186 and the guide block 182. The knife blade assembly 58 is
pivotally connected to the underside of the disk drive pusher 48,
and is guided by the housing guide 186 and the guide block 182. The
indexing disk drive arm 50 is also connected to the disk drive
pusher 48, and is partially guided by the guide block 182. The
puller handle 32 comprises an upper puller handle 194 and a lower
puller handle 196 connected to each other by snap-press fittings
198 that pass through holes 200 in the rear end 202 of the disk
drive pusher 48. In the preferred embodiment shown, the upper
puller handle 194 and the lower puller handle 196 each have a
concaved, textured outer surface (i.e., the top and bottom surfaces
of the puller handle 32) to facilitate gripping of the puller
handle 32 between the thumb and finger of the user's hand. The
cover mechanism 188 is affixed to the guide block 182 with the disk
drive pusher 48 and the housing guide 186 disposed therebetween.
The sensor actuator 40 is attached to the guide block 182 and is
engaged by the front end 204 of the disk drive pusher 48 when the
disk drive pusher 48 is in the testing position. The button release
66 is slidably connected to the cover mechanism 188 so as to engage
the front end 204 of the disk drive pusher 48 when the disk drive
pusher 48 is in the testing position.
[0070] In addition, an indexing disk 30 is rotatably secured to the
disk drive mechanism 34 by a retainer disk 206 connected through
the indexing disk 30 and into guide block 182. As best seen in FIG.
14, the retainer disk 206 has a pair of latch arms 208 that extend
through a central hole 210 in the indexing disk 30 and latch into
an opening 212 in the guide block 182. As mentioned above, the
indexing disk 30 includes a plurality of pins 44 protruding from
the lower surface 214 thereof. These pins 44 are configured to
engage notches 324 on the sensor pack 300 (see FIG. 4) so as to
align and rotate the sensor pack 300 in accordance with the
position of the indexing disk 30. Hence, the pins 44 and the
notches 324 have the dual purpose of retaining the sensor pack 300
on the indexing disk 30 so that the sensor pack 300 will rotate
with the indexing disk 30 and of positioning the sensor pack 300 in
proper circumferential alignment relative to the indexing disk
30.
[0071] As previously indicated, the disk drive pusher 48 is pulled
away from the rear end 16 of the housing 12 (away from the testing
end 14) by the user manually exerting a pulling force on the puller
handle 32 to move the handle 32 from the standby position to the
extended position. As the puller handle 32 is pulled away from the
rear end 22 of the upper case 18, the disk drive pusher 48 is
guided in a lateral direction by the guide block 182, the housing
guide 186, and the cover mechanism 188. As the disk drive pusher 48
slides towards the rear end 22 on the upper case 18, the indexing
disk drive arm 50 causes the indexing disk 30 to rotate.
[0072] The indexing disk drive arm 50 extends rearwardly from the
disk drive pusher 48. The indexing disk drive arm 50 includes a
plate spring 54 made of spring type material such as stainless
steel so as to bias the arm 50 outwardly from the disk drive pusher
48. A cam button 52 is affixed to the distal end of the arm 50, and
is configured to engage the upper surface 216 (as viewed in FIG.
13) of the indexing disk 30. In particular, the indexing disk drive
arm 50 is bent so as to protrude downwardly through a slot 218 in
the guide block 182 such that the cam button 52 projects outwardly
from the surface thereof. The slot 218 is designed such that the
indexing disk drive arm 50 and the cam button 52 can move along the
slot 218 as the disk drive pusher 48 is moved back and forth during
the testing procedure. The slot 218 also prevents the indexing disk
drive arm 50 from moving sideways with respect to the disk drive
pusher 48 (i.e., it provides lateral support to the indexing disk
drive arm 50).
[0073] As best seen in FIG. 13, the upper surface 216 of the
indexing disk 30 comprises a series of radially extending grooves
60 and a plurality of curvilinearly extending grooves 56. The cam
button 52 is configured to ride along these grooves 56 and 60
during the movement of the disk drive pusher 48. As the disk drive
pusher 48 slides towards the rear end 22 of the upper case 18, the
cam button 52 moves along one of the curvilinearly extending
grooves 56. This causes the indexing disk 30 to rotate. In the
preferred embodiment shown, there are ten radially extending
grooves 60 and ten curvilinearly extending grooves 56 equally
spaced about the circumference of the indexing disk 30, with each
radially extending groove 60 being disposed between a pair of
curvilinearly extending grooves 56. Accordingly, the movement of
the disk drive pusher 48 towards the rear end 22 on the upper case
18 results in a {fraction (1/10)}.sup.th rotation of the indexing
disk 30.
[0074] As the puller handle 32 is pulled away from the rear end 16
of the housing 12 to a fully extended position, the cam button 52
passes over an outer step 220 that separates the outer end 222 of
the curvilinearly extending groove 56 from the adjacent radially
extending groove 60. The outer step 220 is formed by the difference
in depth between the outer end 222 of the curvilinearly extending
groove 56 and the outer end 224 of the adjacent radially extending
groove 60. In particular, the outer end 224 of the radially
extending groove 60 is deeper than the outer end 222 of the
curvilinearly extending groove 56. Thus, when the cam button 52
moves from the curvilinearly extending groove 56 into the adjacent
radially extending groove 60, the biasing force of the plate spring
54 of the indexing disk drive arm 50 causes the cam button 52 to
travel downwardly past the outer step 220. The outer step 220
prevents the cam button 52 from re-entering the outer end 222 of
the curvilinearly extending groove 56 when the direction of travel
of the disk drive pusher 48 is reversed (as will be explained
below).
[0075] Rotation of the indexing disk 30 causes the sensor pack 300
to likewise rotate so that the next available sensor cavity 304 is
placed in a standby position adjacent to the testing end 14 of the
housing 12. The sensor pack 300 rotates with the indexing disk 30
because of the engagement of the notches 324 on the sensor pack 300
by the pins 44 on the indexing disk 30. As explained above, each
sensor cavity 304 contains a disposable sensor 302 that is used
during the glucose testing procedure.
[0076] Further rearward movement of the disk drive pusher 48 is
prevented by a rear wall 226 on the guide block 182. In the
preferred embodiment shown, the rear wall 226 includes a slotted
housing 180 for holding the elastomeric connector 174 that connects
the electronics assembly 62 to the flex circuit 156 disposed in the
lower case 24. An interior edge 228 of the disk drive pusher 48
engages the rear wall 226 on the guide block 182 when the disk
drive pusher 48 is in the fully extended position (see FIG. 6).
[0077] From the fully extended position, the puller handle 32 is
then manually pushed inwardly back past the standby position (FIG.
1) and into a testing position (FIG. 7). As previously indicated,
the inward movement of the puller handle 32 causes the disk drive
mechanism 34 to remove a sensor 302 from the sensor pack 300 and
place the sensor 302 into a testing position.
[0078] As best seen in FIGS. 13 and 14, the disk drive mechanism 34
includes a knife blade assembly 58 that is pivotally mounted to the
disk drive pusher 48. The knife blade assembly 58 comprises a swing
arm 230 having a first end 232 that is pivotally connected to the
disk drive pusher 48 by a pair of pivot pins 234. A knife blade 36
is connected to the second end 236 of the swing arm 230. The second
end 236 of the swing arm 230 also includes a first cam follower 238
and a second cam follower 240, each in the shape of a transversely
extending post. The first cam follower 238 is configured to follow
a pathway formed on one side of the knife blade assembly 58 by the
guide block 182, the housing guide 186, and the cover mechanism
188. In particular, this pathway is formed by a cam projection 242
on the housing guide 186 that forms an upper pathway 244 between
the cam projection 242 and the cover mechanism 188 and a lower
pathway 246 between the cam projection 242 and the guide block 182.
When the first cam follower 238 is disposed in the upper pathway
244, the knife blade 36 is in the retracted position. On the other
hand, when the first cam follower 238 is disposed in the lower
pathway 246, then the knife blade 36 is in the extended position.
The upper pathway 244 and the lower pathway 246 are connected
together at both ends of the cam projection 242 so as to form a
continuous loop about which the first cam follower 238 can
travel.
[0079] The second cam follower 240 engages a cam spring 248
attached to the housing guide 186. As will be explained below, the
cam spring 248 guides the knife blade assembly 58 from the lower
pathway 246 to the upper pathway 244 when the disk drive pusher 48
is initially pulled rearward from standby position towards the
extended position. The disk drive pusher 48 also comprises a spring
250 for biasing the knife blade 36 towards the extended position
when the disk drive pusher 48 is initially pushed forward from the
extended position towards the testing position. In the preferred
embodiment shown, the spring 250 comprises a plate spring that
presses against the upper side of the swing arm 230.
[0080] As the puller handle 32 is manually pushed from the extended
position to the testing position, the disk drive pusher 48 is
pushed laterally towards the testing or front end 14 of the housing
12. As the disk drive pusher 48 begins to move forward, the spring
250 biases the swing arm 230 downwardly towards the indexing disk
30 so that the first cam follower 238 engages a sloped surface 252
on the interior end 268 of the cam projection 242 and is forced
into the lower pathway 246. This causes the knife blade 36 to
assume an extended position whereby the knife blade 36 projects
outwardly through a knife slot 46 in the indexing disk 30 to pierce
the protective foil 310 covering one of the sensor cavities 304 and
engage the notch 312 on the back end 308 of the sensor 302
contained therein. As the disk drive pusher 48 continues to move
towards the front end 20 of the upper case 18, the first cam
follower 238 continues along the lower pathway 246, thereby causing
the knife blade 36 to remain in the extended position projecting
through the knife slot 46 so that it will travel along the knife
slot 46 and push the sensor 302 forward out of the sensor cavity
304 and into a testing position at the front end 14 of the housing
12. The sensor 302 is in the testing position when the front end
306 of the sensor 302 projects out of the sensor opening 254 formed
on the front end of the guide block 182. While in the testing
position, the sensor 302 is prevented from being pushed back
through the sensor opening 254 by the engagement of the knife blade
36 against the notch 312 on the back end 308 of the sensor 302.
[0081] As the disk drive pusher 48 reaches the testing position,
the front end 204 of the disk drive pusher 48 simultaneously
engages the sensor actuator 40 and the button release 66. In
particular, the front end 204 of the disk drive pusher 48 engages
and pushes the button release 66 outwardly so as to project
upwardly from the upper surface of the upper case 18. At the same
time, the front end 204 of the disk drive pusher 48 engages a
contact pad 256 on the sensor actuator 40 so as to force the sensor
actuator 40 downward. This downward motion causes a pair of metal
contacts 38 on the sensor actuator 40 to project into the sensor
opening 254 on the guide block 182 and engage the contacts 314 on
the sensor 302 for the glucose testing procedure. The metal
contacts 38 also apply a frictional force to the sensor 302 so that
the sensor 302 does not prematurely fall out of the sensor opening
254 prior to completion of the glucose testing procedure. In the
preferred embodiment shown, the metal contacts 38 are somewhat
flexible and are made of stainless steel. The housing guide 186
includes support ribs 187 disposed adjacent to the metal contacts
38 so as to prevent the metal contacts 38 from bending. As
explained above, the metal contacts 38 permit the transmission of
electrical signals between the sensor 302 and the electronics
assembly 62 during the glucose testing procedure.
[0082] When the glucose testing procedure is complete, the button
release 66 is depressed to release the sensor 302 from the testing
position. The button release 66 has a sloped contact surface 258
that engages the front end 204 of the disk drive pusher 48 at an
angle. As the button release 66 is depressed, the sloped contact
surface 258 slides along the front end 204 of the disk drive pusher
48, thereby causing the disk drive pusher 48 to move rearward from
the testing position and into the standby position. In the
preferred embodiment shown, the disk drive pusher 48 is moved
laterally a distance of 0.080 inches. The movement of the disk
drive pusher 48 to the standby position also causes the front end
204 of the disk drive pusher 48 to disengage from the contact pad
256 on the sensor actuator 40, thereby allowing the sensor actuator
40 to move away from and disengage the sensor 302. The sensor 302
can then be removed by tipping the front end 14 of the sensor
dispensing instrument 10 downwardly.
[0083] As mentioned above, when the disk drive pusher 48 is pushed
from the extended position towards the testing position, the cam
button 52 on the indexing disk drive arm 50 travels along one of
the radially extending grooves 60 to prevent the indexing disk 30
and the sensor pack 300 from rotating. The radially extending
groove 60 includes a sloped portion 260 that changes the depth of
the groove 60. In particular, the sloped portion 260 decreases the
depth of the radially extending groove 60 so that the middle
portion of the radially extending groove 60 is shallower than the
curvilinearly extending grooves 56. The radially extending groove
60 also comprises an inner step 262 near its inner end 264 (i.e.,
near the center of the indexing disk 30). The inner step 262 is
formed along the juncture of the inner end 264 of the radially
extending groove 60 and the inner end 266 of the curvilinearly
extending groove 56. As the disk drive pusher 48 is pushed from the
extended position towards the testing position, the cam button 52
travels up the sloped portion 260 of the radially extending groove
60, past the inner step 262, and into the adjacent curvilinearly
extending groove 56. The biasing force of the plate spring 54 of
the indexing disk drive arm 50 causes the cam button 52 to travel
downwardly past the inner step 262. The inner step 262 prevents the
cam button 52 from re-entering the radially extending groove 60
when the direction of travel of the disk drive pusher 48 is
reversed (as explained above in connection with the outward
movement of the disk drive pusher 48).
[0084] As the disk drive pusher 48 reaches the testing position,
the first cam follower 238 passes the exterior end 270 of the cam
projection 242. At the same time, the second cam follower 240
passes over the end of the cam spring 248, which retracts upwardly
and out of the way as the first cam follower 238 nears the exterior
end 270 of the cam projection 242. Once the first cam follower 238
has passed the end of the cam spring 248, the cam spring 248 moves
downwardly so as to engage and guide the second cam follower 240
upwardly when the direction of travel of the disk drive pusher 48
is reversed and pulled outward towards the extended position. In
particular, when the disk drive pusher 48 is subsequently pulled
outward towards the extended position, the cam spring 248 guides
the second cam follower 240 upwardly so that the first cam follower
238 enters the upper pathway 244 and the knife blade 36 is
retracted.
[0085] As explained above, the disk drive pusher 48 is pulled
outwardly to initiate the testing procedure. During the outward
motion of the disk drive pusher 48, the cam button 52 on the
indexing disk drive arm 50 travels along one of the curvilinearly
extending grooves 56 so as to rotate the indexing disk 30. During
this outward motion, the first cam follower 238 on the knife blade
assembly 58 travels along the upper pathway 244. As a result, the
knife blade 36 is retracted from the knife slot 46 on the indexing
disk 30 so that the indexing disk 30 is free to rotate in response
to action of the cam button 52 in the curvilinearly extending
groove 56. As the disk drive pusher 48 reaches the fully extended
position, the first cam follower 238 passes the interior end 268 of
the cam projection 242 and is guided into the lower pathway 246 by
the biasing force of the spring 250 on the swing arm 230 of the
knife blade assembly 58.
[0086] Prior to operating the sensor dispensing instrument 10, a
sensor pack 300 must first be loaded into the sensor dispensing
instrument 10 if one has not already been so loaded, or if all of
the sensors 302 in the previously loaded sensor pack 300 have been
used. To load a sensor pack 300, the lower case 24 and the upper
case 18 are opened by depressing the latch 72 on the lower case 24.
In the preferred embodiment shown, the opening of the lower case 24
and the upper case 18 causes the elastomeric connector 174 to
separate from the contacts 166 on the autocal disk 158, thereby
breaking the electrical connection between the autocal disk 158 and
the electronics assembly 62. This causes an electronic counter
(which is part of the electronics assembly 62) that keeps count of
the number of unused sensors 302 in the sensor pack 300 to re-set
to zero (0).
[0087] The opened housing 12 is then turned so that the lower
surface 214 of the indexing disk 30 faces upwardly as shown in FIG.
3. A sensor pack 300 is then placed on the indexing disk 30 by
aligning the notches 324 along the periphery of the sensor pack 300
with the pins 44 on the indexing disk 30. The lower case 24 is then
pivoted on to the upper case 18 so as to enclose the sensor pack
300 within the housing. Once the lower case 24 is secured to the
upper case 18 by the latch 72, the sensor dispensing instrument 10
is ready for operation.
[0088] The following is a brief description of the operation of the
sensor dispensing instrument 10. First, the puller handle 32 is
manually pulled from a standby position (FIG. 1) adjacent the rear
end 16 of the housing 12 to an extended position (FIG. 6) away from
the rear end 16 of the housing 12. The outward movement of the
puller handle 32 causes the sensor dispensing instrument 10 to turn
ON. The outward movement of the puller handle 32 also causes the
cam button 52 on the indexing disk drive arm 50 to travel along one
of the curvilinearly extending grooves 56 on the upper surface 216
of the indexing disk 30 so as to rotate the indexing disk 30
{fraction (1/10)}.sup.th of a complete rotation. The rotation of
the indexing disk 30 causes the sensor pack 300 to be rotated so
that the next one of the sensor cavities 304 is placed in a standby
position aligned with the testing end 14 of the housing 12. At the
same time, the knife blade assembly 58 is retracted and moved
towards the center of the indexing disk 30.
[0089] Next, the puller handle 32 is manually pushed inwardly from
the extended position (FIG. 6) back past the standby position (FIG.
1) and into a testing position (FIG. 7). The inward movement of the
puller handle 32 causes the knife blade assembly 58 to pivot
downwardly so that a knife blade 36 pierces a portion of the
protective foil 310 covering the sensor cavity 304 in the standby
position and engages the sensor 302 in the sensor cavity 304. As
the puller handle 32 continues to move back towards the housing 12,
the knife blade assembly 58 forces the sensor 302 out of the sensor
cavity 304 and into a testing position at the front end 14 of the
housing 12. At the same time, the cam button 52 on the indexing
disk drive arm 50 travels along one of the radially extending
grooves 60 to prevent the indexing disk 30 from rotating.
[0090] After the sensor 302 has been completely ejected from the
sensor cavity 304 and pushed into a testing position projecting out
from the front end 14 of the housing 12, the sensor actuator 40
engages the sensor 302 to hold the sensor 302 in the testing
position and to couple the sensor 302 to the electronics assembly
62. The front end 306 of the sensor is then inserted into a drop of
blood to be tested, whereby the blood is analyzed by the
electronics assembly 62. The results of the analysis are then
displayed on the liquid crystal display 64 of the sensor dispensing
instrument 10.
[0091] Once the analysis of the blood is complete, the button
release 66 on the upper case 18 is depressed so as to disengage the
sensor actuator 40 and release the sensor 302, which can be
disposed of by tipping the front end 14 of the housing 12
downwardly.
[0092] While the invention has been described with reference to
details of the illustrated embodiment, these details are not
intended to limit the scope of the invention as defined in the
appended claims. For example, the sensor dispensing instrument 10
can be used for testing fluids other than blood glucose. In fact,
the sensor dispensing instrument 10 can be used in connection with
the analysis of any type of chemistry fluid that can be analyzed by
means of a reagent material.
* * * * *