U.S. patent application number 16/995527 was filed with the patent office on 2020-12-03 for ratchet drive for on body delivery system.
The applicant listed for this patent is Insulet Corporation. Invention is credited to Simon KOZIN, Maureen MCCAFFREY, David NAZZARO.
Application Number | 20200376191 16/995527 |
Document ID | / |
Family ID | 1000005021582 |
Filed Date | 2020-12-03 |
View All Diagrams
United States Patent
Application |
20200376191 |
Kind Code |
A1 |
NAZZARO; David ; et
al. |
December 3, 2020 |
RATCHET DRIVE FOR ON BODY DELIVERY SYSTEM
Abstract
Ratchet-based drive systems for more reliable and safer drug
delivery are provided. The ratchet-based drive systems restrict
angular movement and/or linear movement of components that cause a
plunger to expel a liquid drug from a drug container. Movement of
the components can be restricted to correspond to a predetermined
or desired portion of the liquid drug. In the case that control of
the drive system is lost or fails, the maximum amount of drug that
could be delivered is limited to a known amount, thereby reducing
the likelihood of an overdose.
Inventors: |
NAZZARO; David; (Groveland,
MA) ; KOZIN; Simon; (Lexington, MA) ;
MCCAFFREY; Maureen; (Boston, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Insulet Corporation |
Acton |
MA |
US |
|
|
Family ID: |
1000005021582 |
Appl. No.: |
16/995527 |
Filed: |
August 17, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15809491 |
Nov 10, 2017 |
10780217 |
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16995527 |
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62439822 |
Dec 28, 2016 |
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62420382 |
Nov 10, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 5/31568 20130101;
A61M 5/31546 20130101; A61M 5/14248 20130101; A61M 2005/3154
20130101; A61M 2005/14533 20130101; A61M 5/16877 20130101; A61M
5/1452 20130101; A61M 5/31536 20130101; A61M 5/16804 20130101 |
International
Class: |
A61M 5/145 20060101
A61M005/145; A61M 5/142 20060101 A61M005/142; A61M 5/168 20060101
A61M005/168 |
Claims
1. An on-body drug delivery system, comprising: a reservoir
configured to contain a liquid drug; a plunger configured to seal
an end of the reservoir; a rack having a plurality of teeth and
coupled to the plunger, wherein the rack is configured to move the
plunger within the reservoir; an arm having a pawl configured to
engage the rack; and a power source configured to extend and
retract the arm, wherein extending the arm causes the plunger to
expel an amount of the liquid drug.
2. The system of claim 1, wherein the arm is sized such that
extension of the arm is in a direction parallel to movement of the
rack corresponds to the amount of the liquid drug being
expelled.
3. The system of claim 1, wherein the arm has a length enabling the
amount of the liquid drug expelled by the plunger a desired amount
of the liquid drug to be when a corresponding amount of the length
of the arm is extended.
4. The system of claim 1, wherein the power source is operable to
move the arm backward in a direction away from the plunger.
5. The system of claim 4, wherein the pawl is configured to:
disengage the rack when the arm is moved backward.
6. The system of claim 1, wherein the pawl is configured to: rotate
away from when the rack when the arm is moved.
7. The system of claim 1, wherein the plunger is configured to
expel a portion of a liquid drug stored in the reservoir when moved
in a linear direction.
8. The system of claim 1, further comprising: a controller couple
to the power source, wherein the controller is operable to control
the power source.
9. The system of claim 8, wherein the controller is further
operable to: track movement of the arm; and maintain a count of a
number of times the arm is moved to expel the liquid drug.
10. A method, comprising: extending an arm coupled to pawl that is
engaged with a rack in a first direction, wherein the arm is driven
from a first pos from an initial position to a final position; in
response to extending the arm, expelling a dose of a liquid drug
from a drug container by a plunger coupled to the rack; retracting
the arm in a second direction, opposite the first direction; in
response to retracting the arm in the second direction, disengaging
the pawl from the rack; and stopping retracting of the arm in the
second direction upon return to the initial position in preparation
for expelling another dose of the liquid drug.
11. The method of claim 10, further comprising: re-engaging the
rack by the pawl when the arm stops retracting in the second
direction.
12. The method of claim 11, wherein disengaging the pawl from the
rack comprises: rotating an end of the pawl to disengage the pawl
from a tooth on the rack.
13. The method of claim 10, wherein extending the arm in the first
direction further comprises: advancing the plunger toward an end of
the drug container.
14. The method of claim 10, further comprising: activating a power
source coupled to the arm to deliver the dose of the liquid drug by
causing the power source to extend the arm.
15. The method of claim 14, further comprising: after returning to
the initial position, reactivating the power source to a deliver
the other dose of the liquid drug by causing the power source to
extend the arm.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/809,491, filed Nov. 10, 2017, which claims
the benefit of U.S. Provisional Application No. 62/420,382, filed
Nov. 10, 2016, and U.S. Provisional Application No. 62/439,822,
filed Dec. 28, 2016, each of which is incorporated herein by
reference in its entirety.
TECHNICAL FIELD
[0002] Embodiments generally relate to medication delivery. More
particularly, embodiments relate to drive systems for drug delivery
devices.
BACKGROUND
[0003] An on-body delivery system (OBDS) can be used to deliver
drug dosages to a user over time. During a control system failure
of the OBDS, there can be a risk of delivering too much of a drug
to the user resulting in a possible drug overdose condition.
Accordingly, there is a need for an OBDS having a drive system for
delivering a drug to a user that can prevent delivery of too much
of a drug to the user during a system failure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 illustrates a first exemplary ratchet drive
system.
[0005] FIG. 2 illustrates the first ratchet drive system in an idle
state.
[0006] FIG. 3 illustrates the first ratchet drive system during
delivery of a drug.
[0007] FIG. 4 illustrates the first ratchet drive system after
delivery of the drug.
[0008] FIG. 5 illustrates the first ratchet drive system during a
first phase of reset.
[0009] FIG. 6 illustrates the first ratchet drive system during a
second phase of reset.
[0010] FIG. 7 illustrates the first ratchet drive system in
relation to a controller.
[0011] FIG. 8 illustrates a second exemplary ratchet drive
system.
[0012] FIG. 9 illustrates the second ratchet drive system after
delivery of a drug.
[0013] FIG. 10 illustrates the first ratchet drive system in
relation to a drug container.
[0014] FIG. 11 illustrates a third exemplary ratchet drive
system.
[0015] FIG. 12 illustrates the third ratchet drive system in an
idle state.
[0016] FIG. 13 illustrates the third ratchet drive system during
delivery of a drug.
[0017] FIG. 14 illustrates the third ratchet drive system after
delivery of the drug during a first phase of reset.
[0018] FIG. 15 illustrates the third ratchet drive system during a
second phase of reset.
[0019] FIG. 16 illustrates a fourth ratchet drive system during
delivery of a drug.
[0020] FIG. 17 illustrates the fourth ratchet drive system after
delivery of the drug during a first phase of reset.
[0021] FIG. 18 illustrates the fourth ratchet drive system during a
second phase of reset.
[0022] FIG. 19 illustrates the first ratchet drive system in
relation to a power source.
DETAILED DESCRIPTION
[0023] This disclosure presents various systems, components, and
methods related to a drug delivery device. Each of the systems,
components, and methods disclosed herein provides one or more
advantages over conventional systems, components, and methods.
[0024] Various embodiments provide for drug delivery using
ratchet-based drive systems. The ratchet-based drive systems
restrict angular movement and/or linear movement of components that
cause a plunger to expel a liquid drug from a drug container.
Movement of the components can be restricted to expel only a
predetermined or desired amount of the liquid drug. In the case
that control of the drive system is lost or fails, the maximum
amount of drug that could be delivered is limited to a known
amount, thereby reducing the likelihood of an overdose. The
predetermined amount of the liquid drug expelled can correspond to
any portion of the liquid drug including a single dose of the
liquid drug or a portion thereof.
[0025] FIG. 1 illustrates a first exemplary ratchet drive system
100. The ratchet drive system 100 can be incorporated as part of an
on-body delivery system (OBDS) as described herein. The ratchet
drive system 100 can include a lead screw 102, a ratchet gear 104,
a ratchet carrier 106, a first pawl 108-1, a second pawl 108-2, a
first carrier stop 110-1, and a second carrier stop 110-2. As shown
in FIG. 1, the lead screw 102 can be coupled to the ratchet gear
104 and can be positioned through the ratchet gear 104 (e.g.,
through a center hole of the ratchet gear 104). The lead screw 102
can include threads that engage the ratchet gear 104. The lead
screw 102 can also be positioned through the ratchet carrier (e.g.,
through a center hole of the ratchet carrier 106). An end of the
lead screw 102 that extends beyond the ratchet carrier 106 can be
coupled to a plunger positioned within a drug cartridge (not shown
in FIG. 1). The ratchet drive system 100 can be operated such that
rotation of the lead screw 102 can cause the plunger to be
advanced, thereby expelling a portion of a liquid drug stored in
the drug cartridge. The ratchet drive system 100 can prevent
over-delivery (e.g., overdose) of the liquid drug (e.g., during
system failure of the OBDS incorporating the ratchet drive system
100) to ensure safe delivery of the liquid drug and operation of
the OBDS as described herein.
[0026] The first and second pawls 108-1 and 108-2 can be coupled to
the ratchet carrier 106. As shown in FIG. 1, the first and second
pawls 108-1 and 108-2 can be positioned to engage the ratchet gear
104 (e.g., the outer teeth of the ratchet gear 104). To expel a
portion of the liquid drug from the drug container, the ratchet
carrier 104 can be rotated (e.g., about a central axis of rotation
114 in a clockwise direction with respect to the depiction of the
ratchet drive system 100 in FIG. 1). The ratchet carrier 106 can be
rotated by an amount corresponding to the position of the second
carrier stop 110-2. That is, the ratchet carrier 106 can be rotated
such that an extension or protrusion 112 of the ratchet carrier 106
moves from the first carrier stop 110-1 to the second carrier stop
110-2. The extension 112 of the ratchet carrier 106 can be stopped
by or can be positioned adjacent to the second carrier stop 110-2
when a desired portion (e.g., a dose or portion thereof) of the
liquid drug has been expelled from the drug container. The first
and second carrier stops 110-1 and 110-2 can be coupled to a
portion of the OBDS incorporating the ratchet drive system 100.
[0027] When the ratchet carrier 106 is rotated from the first
carrier stop 110-1 toward the second carrier stop 110-2, the
ratchet gear 104 can be caused to similarly rotate based on the
engagement of the first and second pawls 108-1 and 108-2. That is,
the first and second pawls 108-1 and 108-2 can couple the ratchet
carrier 106 to the ratchet gear 104. The rotation of the ratchet
gear 104 can cause the lead screw 102 to also rotate. The ratchet
gear 104 can be tightly coupled to the lead screw 102 to ensure
that rotation of the ratchet gear 104 results in rotation of the
lead screw 102. Rotation of the lead screw 102 can cause the lead
screw 102 to advance in a direction 116 that can be parallel to the
central axis 114. This movement of the lead screw 102 can cause the
plunger to move further into the drug container, which can cause a
portion of the liquid drug stored therein to be expelled. The
linear displacement of the lead screw 102 in the direction 116
caused by rotation of the ratchet carrier 106 and the ratchet gear
104 can be based on a thread pitch of the lead screw 102 which can
be adjusted for particular applications and drug dosages. The
amount of liquid drug expelled can correspond to a predetermined or
desired amount of the liquid drug stored in the drug container. In
various embodiments, any portion of the liquid drug can be expelled
including, for example, a single dose of the liquid drug or a
portion thereof. Accordingly, in various embodiments, movement of
the ratchet carrier 106 from the first carrier stop 110-1 to the
second carrier stop 110-2 can cause a single dose of the liquid
drug to be expelled from the drug container for delivery to a
patient or user.
[0028] After the ratchet carrier 106 has been moved to a position
corresponding to the second carrier stop 110-2, the ratchet carrier
106 can be rotated back to a position corresponding to the first
carrier stop 110-2 (e.g., as shown in FIG. 1). As shown in FIG. 1,
the ratchet drive system 100 can be in an initial or reset state
awaiting activation so as to rotate the ratchet carrier 106 toward
the second carrier stop 110-2 for delivery of a portion of the
liquid drug. Prior to rotating the ratchet carrier 106 back to a
position corresponding the first carrier stop 110-1 as shown in
FIG. 1, the first and second pawls 108-1 and 108-2 can be
disengaged from the ratchet gear 104. Releasing the first and
second pawls 108-1 and 108-2 from the ratchet gear 104 can prevent
the ratchet gear 104 from rotating when the ratchet carrier 106 is
rotated back toward the first carrier stop 110-1. As a result, the
position of the lead screw 102 is maintained (e.g., the lead screw
102 is not advanced in the direction 116 when the ratchet carrier
106 is rotated back toward the first carrier stop 110-1). The first
and second pawls 108-1 and 108-2 can then re-engage the ratchet
gear 104 after the ratchet carrier 104 is moved back to the
position shown in FIG. 1. The ratchet drive system 100 can then
await a subsequent activation (e.g., an instruction to rotate the
ratchet carrier 106 toward the second carrier stop 110-2) for a
next cycle of drug delivery. The first and second pawls 108-1 and
108-2 can be coupled to a control system that can rotate or
otherwise adjust the position of the first and second pawls 108-1
and 108-2 to engage and disengage the ratchet gear 104 as
desired.
[0029] In various embodiments, the ratchet carrier 106 can be
positioned around the ratchet gear 104. The ratchet gear 104 can be
positioned within an opening of the ratchet carrier 106. In various
embodiments, the ratchet drive system 100 can include a single pawl
or more than two pawls.
[0030] The operation of the ratchet drive system 100 can prevent
over-delivery of the liquid drug that the ratchet drive system 100
can be used to expel from the drug container. The second carrier
stop 110-2 can prevent the lead screw 102 from rotating more than a
desired amount, by restricting further rotation of the ratchet
carrier 106, thereby restricting further advancement of the plunger
coupled to the lead screw 102. As a result, further delivery of the
liquid drug is prevented. During system failure of the OBDS that
incorporates the ratchet drive system 100 (e.g., a power failure),
the risk of over-delivery of the liquid drug is mitigated by the
restricted movement of the lead screw 102. Precise dosing of the
liquid drug can also be provided by the ratchet drive system
100.
[0031] The first and second carrier stops 110-1 and 110-2 can be
displaced by any amount. As shown in FIG. 1, the first and second
carrier stops 110-1 and 110-2 are displaced by approximately 180
degrees but are not so limited. The displacement of the first and
second carrier stops 110-1 and 110-2 can correspond to delivery of
a predetermined or desired amount of the liquid drug when the
ratchet carrier 106 is rotated from the first carrier stop 110-1 to
the second carrier stop 110-2 but is not so limited. In various
embodiments, the predetermined amount of the liquid drug can
correspond to a single dose of the liquid drug or a portion
thereof.
[0032] The ratchet carrier 106 can be coupled to a power source to
effectuate rotation of the ratchet carrier 106. The power source
can comprise a motor but is not so limited. The power source can
comprise a mechanical system or an electromechanical system. The
power source can cause the ratchet carrier 106 to be rotated toward
the second carrier stop 110-1 based upon an activation signal
provided by the OBDS (e.g., a controller). The activation can be
automatically provided or can be generated responsive to a user
input. The power source can cause the ratchet carrier 106 to rotate
back toward the first carrier stop 110-1 immediately after
providing the dosage of the liquid drug or after a predetermined
delay.
[0033] The OBDS in which the ratchet drive system 100 can be
incorporated can be any type of wearable drug delivery system such
as, for example, the OmniPod.RTM. (Insulet Corporation, Billerica,
Mass.) insulin delivery device and/or a drug delivery device such
as those described in U.S. Pat. Nos. 7,303,549, 7,137,964, or U.S.
Pat. No. 6,740,059, each of which is incorporated herein by
reference in its entirety.
[0034] FIG. 2 illustrates a second view of the ratchet drive system
100 depicted in FIG. 1. FIG. 1 can represent an isometric view of
the ratchet drive system 100. FIG. 2 can represent a corresponding
front view of the ratchet drive system 100. As shown in FIG. 2, the
extension 112 can be positioned adjacent to the first carrier stop
110-1 and the first and second pawls 108-1 and 108-2 can be engaged
with the ratchet gear 104. FIG. 2 can represent the ratchet drive
system 100 in an initial or idle state prior to being activated to
rotate the ratchet carrier 106. Further, the ratchet carrier 106
can be considered to be in an initial position as depicted in FIG.
2.
[0035] FIG. 3 illustrates a front view of the ratchet drive system
100 during delivery of the liquid drug. As shown in FIG. 3, the
ratchet carrier 106 is rotated in a direction 302 (e.g., a
clockwise direction relative to the depiction of the ratchet drive
system 100 in FIG. 3). As shown, the extension 112 is moving toward
the second carrier stop 110-2. The first and second pawls 108-1 and
108-2, the ratchet gear 104, and the lead screw 102 each
correspondingly rotate in the direction 302. Further, the lead
screw 102 is linearly displaced in a direction parallel to the
central axis 114.
[0036] FIG. 4 illustrates a front view of the ratchet drive system
100 after delivery of the liquid drug. As shown in FIG. 4, the
ratchet carrier 106 has been rotated such that the extension 112 is
positioned adjacent to the second carrier stop 110-2. The second
carrier stop 110-2 can prevent the ratchet carrier 106 from
rotating any further, thereby preventing further linear
displacement of the lead screw 102. The rotation of the ratchet
carrier 106 from the first carrier stop 110-1 to the second carrier
stop 110-2 can correspond to expelling and delivering a desired
amount or portion of the liquid drug. The ratchet carrier 106 can
be considered to be in a final position as depicted in FIG. 4.
[0037] FIG. 5 illustrates a front view of the ratchet drive system
100 during an initial resetting of the ratchet drive system 100. As
shown in FIG. 5, the first and second pawls 108-1 and 108-2 are
disengaged from the ratchet gear 104. Accordingly, when the ratchet
carrier 106 is rotated back toward the first carrier stop 110-1,
the ratchet gear 104 and the lead screw 102 will remain stationary.
As a result, none of the liquid drug will be expelled from the drug
container when the ratchet carrier 106 is rotated back towards the
first carrier stop 110-1.
[0038] FIG. 6 illustrates a front view of the ratchet drive system
100 during further resetting of the ratchet drive system 100. As
shown in FIG. 6, the ratchet carrier 106 is rotated in a direction
602 (e.g., a counter-clockwise direction relative to the depiction
of the ratchet drive system 100 in FIG. 6). As shown, the extension
112 is moved toward the first carrier stop 110-1 and is shown
positioned adjacent to the first carrier stop 110-1 (e.g.,
corresponding to the initial position of the ratchet carrier 106).
The first and second pawls 108-1 and 108-2 are similarly rotated in
the direction 602. After the ratchet carrier 106 is fully rotated
back to the initial position (e.g., to a reset or the initial
position), the first and second pawls 108-1 and 108-2 can re-engage
the ratchet gear 104 (e.g., as depicted in FIG. 2). The ratchet
drive system 100 can then remain in the reset or idle state until
being activated again to repeat delivery and the reset cycle as
described herein. As with the second carrier stop 110-2, the first
carrier stop 110-1 can also restrict further rotation of the
ratchet carrier 106.
[0039] FIG. 7 illustrates the ratchet drive system 100 with an
exemplary controller 702. The controller 702 can be coupled to the
first carrier stop 110-1, the second carrier stop 110-1, and any
other component of the ratchet drive system 100 such as the ratchet
carrier 106. The controller 702 can direct operation of the ratchet
drive system 100. The first and second carrier stops 110-1 and
110-2 can each include one or more sensors that can inform the
controller 702 as to the position of the ratchet carrier 106. For
example, the first and second carrier stops 110-1 and 110-2 can
each include a sensor that can inform the controller 702 when the
extension 112 is touching or in close proximity to one of the first
and second carrier stops 110-1 and 110-2. Positional information of
the ratchet carrier 106 can also be provided to the controller 702
from rotation of the ratchet carrier 106. The controller 702 can be
coupled to the power source of the ratchet drive system 100 to
direct the power source to rotate the ratchet carrier 106 in a
desired direction based on, for example, positional information of
the ratchet carrier 106 provided by at least the first and second
carrier stops 110-1 and 110-2.
[0040] During delivery of a portion of the liquid drug, the sensor
in the second carrier stop 110-2 can send a signal to the
controller 702 indicating the position of the extension 112 (e.g.,
when the extension touches or is adjacent to the second carrier
stop 110-2). The controller 702 can adjust or stop the rotation of
the ratchet carrier 106 (e.g., in the direction 302) based on
signals received from the second carrier stop 110-2. Further,
signals from the second carrier stop 110-2 can allow the controller
702 to maintain a count of the number of times the extension 112
has reached the second carrier stop 110-2. In this way, a count of
the number of times the drug is delivered or expelled can be
maintained, along with a count of the remaining number of times the
drug can be expelled. In various embodiments, when the portion
expelled corresponds to a desired dose of the liquid drug or
portion thereof, a count of the number of doses of drug delivered
or expelled can be maintained, along with a count of remaining
doses.
[0041] The sensor in the first carrier stop 110-1 can similarly
send a signal to the controller 702 indicating the position of the
extension 112 (e.g., when the extension touches or is adjacent to
the first carrier stop 110-1). The controller 702 can adjust or
stop the rotation of the ratchet carrier 106 (e.g., in the
direction 602) based on signals received from the first carrier
stop 110-1. Signals from the first carrier stop 110-1 can also be
used to maintain a count of the number of times the liquid drug is
delivered or expelled and a count of how many more times the drug
can be expelled before the drug container is substantially empty.
As described above, in various embodiments, when the portion
expelled corresponds to a desired dose of the liquid drug or
portion thereof, the signals from the first carrier stop 110-1 can
enable a count of the number of doses of drug delivered or expelled
can be maintained, along with a count of remaining doses.
[0042] FIG. 8 illustrates a second exemplary ratchet drive system
800. The ratchet drive system 800 can include substantially the
same components of the ratchet drive system 100 and can operate in
a substantially similar manner as the ratchet drive system 100. The
ratchet drive system 800 can include a single carrier stop 802 (as
opposed to two carrier stops as included with the ratchet drive
system 100). The ratchet drive system 800 as shown in FIG. 8 can be
in an initial position or idle state prior to being activated to
deliver a portion of the liquid drug. When activated or instructed
to deliver a portion of the liquid drug, the ratchet carrier 106
can rotate in a clockwise direction (relative to the depiction of
the ratchet drive system 800 in FIG. 8). The extension 112 can
rotate until reaching the other side of the carrier stop 802. In
doing so, the ratchet gear 104 and the lead screw 102 can similarly
rotate. A desired amount of drug can be expelled from the drug
container based on this rotation of the ratchet carrier 106.
[0043] The carrier stop 802 can include one or more sensors for
detecting a position of the ratchet carrier 106. As with the
ratchet drive system 100, the ratchet drive system 800 can further
include a controller for directing operation of the ratchet drive
system 800 based on signals received from one or more sensors of
the carrier stop 802. Like the ratchet drive system 100, the
ratchet drive system 800 can be coupled to a power source (e.g., a
motor) to provide an input for rotating the ratchet carrier
106.
[0044] FIG. 9 illustrates the ratchet drive system 800 after
delivering a portion of the liquid drug. As shown in FIG. 9, the
ratchet carrier 106 has rotated such that the extension 112 is
positioned on the other side of the carrier stop 802 (as compared
to the position of the extension 112 as shown in FIG. 8). The first
and second pawls 108-1 and 108-2 and the ratchet gear 104 have
similarly rotated. The ratchet carrier 106 has rotated just under
360 degrees. For a motor power source, the implementation of the
ratchet drive system 800 with the single carrier stop 802 can
reduce the number of motor cycles used to deliver the same
advancement of the lead screw 102.
[0045] FIG. 10 illustrates a side view of the ratchet drive system
100 in relationship to a drug container 1002. For simplicity, the
first and second carrier stops 110-2 and 110-2 are not shown. As
shown in FIG. 10, the lead screw 102 extends through and beyond the
ratchet carrier 106 (e.g., through a central hole or opening of the
ratchet carrier 106). The ratchet carrier 106 can be coupled to or
positioned adjacent to the drug container 1002. The drug container
1002 can include an area or reservoir 1004 for holding a liquid
drug as described herein. The drug container 1002 can further
include a port 1006 through which the liquid drug stored in the
reservoir 1004 can be expelled out of the drug container 1002.
[0046] The lead screw 102 can be coupled to a plunger 1008. The
plunger 1008 can define a boundary of the reservoir 1004. As
described herein, when the ratchet carrier 106 is rotated in a
first direction to initiate drug delivery, the lead screw 102 can
rotate about the central axis 114. As a result, the lead screw 102
can move in the direction 116 and can push on the plunger 1008 to
drive the plunger 1008 in the direction 116 as well. The movement
of the plunger 1008 in the direction 116 can expel a portion of the
liquid drug stored in the reservoir 1004 from the drug container
1002 (e.g., through the exit port 1006 for subsequent delivery to a
patient).
[0047] The ratchet drive system 100 and additional components
depicted in FIG. 10 can be incorporated into an OBDS as described
herein. The ratchet drive system 800 can be similarly coupled to
the additional components depicted in FIG. 10 as will be understood
by a person of ordinary skill in the art. As described herein, the
ratchet drive systems 100 and 800 can prevent overdose situations
that can occur with conventional drive systems for drug delivery
devices by restricting rotational movement and using multiple
rotational cycles to deliver one or more desired or predetermined
doses of the liquid drug.
[0048] For example, if the power source for the ratchet drive
system 100 suddenly and/or catastrophically failed at any time
(e.g., during delivery of a dose and/or movement of ratchet carrier
106 toward the second carrier stop 110-2), then the second carrier
stop 110-2 can restrict the angular movement of the ratchet carrier
106. As a result, delivery of any further drug can be prevented. In
particular, the second carrier stop 110-2 can block movement of the
ratchet carrier 106 that could be caused by any force such as
inertia or gravity that may attempt to rotate the ratchet carrier
106 any further. As described herein, the maximum angular movement
of the ratchet carrier 106 can be restricted by a desired amount
such that the angular displacement corresponds to a desired drug
delivery, ensuring that drug delivery can be limited to a desired
amount in a runaway operation condition. In various embodiments, as
described above in relation to the other disclosed ratchet drive
systems, any portion of the stored liquid drug can be delivered
during each cycle of movement including, for example, a single
desired dose of the liquid drug or a portion thereof. The ratchet
drive system 800 provides the same prevention of overdose during
such conditions by the carrier stop 802 similarly restricting
movement of the ratchet carrier 106.
[0049] FIG. 19 illustrates the ratchet drive system 100 with an
exemplary power source 1906. The power source 1906 can be a motor.
The motor 1906 can interface with the ratchet drive system 100 as
shown to facilitate movement of the ratchet carrier 106 as
described herein.
[0050] In various embodiments, as shown in FIG. 19, the ratchet
carrier 106 can include gear teeth 1902. The gear teeth 1902 can be
positioned along a perimeter of the ratchet carrier 106 and can
project from the ratchet carrier 106. A gear 1904 can be coupled to
the ratchet carrier 106 as shown. In various embodiments, teeth of
the gear 1904 can interface with the gear teeth 1902 of the ratchet
carrier 106. The gear 1904 can be coupled to the motor 1906. The
motor 1906 can rotate the ratchet gear 1906 as desired and as
described herein by rotation of the gear 1904 as will be understood
by a person of ordinary skill in the art. Accordingly, the motor
1906 can control delivery of the liquid drug by rotating the
ratchet carrier 106 as desired and can rotate the ratchet carrier
106 back to an idle state after delivery. The motor 1906 can
initiate rotation automatically or based on user input.
[0051] In various embodiments, the ratchet drive systems 100 and
800 can be configured to enable a portion of the drug to be
delivered based on both forward and backwards rotation of the
ratchet carrier 106 as will be appreciated by one skilled in the
art.
[0052] FIG. 11 illustrates a third exemplary ratchet drive system
1100. As with the ratchet drive systems 100 and 800, the ratchet
drive system 1100 can be used in an OBDS as described herein. The
ratchet drive system 1100 can include a rack 1102, a plunger 1104,
a power source 1106, an arm 1108, a pawl 1110, and a drug container
1112. As shown in FIG. 11, the rack 1102 can be coupled to the
plunger 1104. The plunger 1104 can be positioned within the drug
container 1112. The power source 1106 can be, for example, a motor
or a linear actuator. The power source 1106 can be coupled to the
arm 1108. The pawl 1110 can be coupled to the arm 1108.
[0053] The ratchet drive system 1100 can be operated such that
linear movement of the arm 1108 (e.g., in a direction away from the
power source 1106) can drive the plunger 1104 further into the drug
container 1112, thereby expelling a portion of a liquid drug stored
in the drug cartridge. Like the ratchet drive systems 100 and 800,
the ratchet drive system 1100 can prevent over-delivery (e.g.,
overdose) of the liquid drug (e.g., during system failure of the
OBDS incorporating the ratchet drive system 1100) to ensure safe
delivery of the liquid drug and operation of the OBDS as described
herein.
[0054] FIG. 11 can represent the ratchet drive system 1100 in an
idle state prior to activation. When activated, the ratchet drive
system 1100 can operate to deliver a desired amount of the stored
liquid drug to a user. Specifically, when activated, the power
source 1106 can cause the arm 1108 to extend (e.g., in a direction
away from the power source 1106). When the arm 1108 extends, the
rack 1102 can be caused to move forward (e.g., in the same
direction that the arm 108 extends) by the coupling of the arm 1108
to the rack 1102 by the pawl 1110. As a result, the plunger 1104 is
driven further into the drug container, expelling a portion of the
stored liquid drug.
[0055] The arm 1108 can be sized and controlled to extend a desired
amount away from the power source 1106 when the ratchet drive
system 1100 is activated. By limiting the amount by which the arm
1108 can extend (e.g., to a maximum extension amount), the movement
of the plunger 1104 can likewise be limited. In this way,
over-delivery can be mitigated by limiting the amount of liquid
drug that can be expelled during each activation of the ratchet
drive system 1100. After the arm 1108 is fully extended, the arm
1108 can be operated to move back to its original position (e.g.,
retracted back toward the power source 1106). The position of the
rack 1102 can be maintained by having the pawl 1110 disengage the
rack 1102 prior to the arm 1108 moving in a direction back toward
the power source 1108.
[0056] The ratchet drive system 1100 can be used with the same
OBDSs described in relation to the ratchet drive systems 100 and
800. Like the ratchet drive systems 100 and 800, a controller can
be used with the ratchet drive system 1100 to direct operation of
the power source 1106 and therefore delivery of the liquid drug.
The controller can direct operation of the power source 1106 based
on, for example, positional information of the plunger 1104, the
rack 1102, and/or the arm 1108. The controller can track delivery
of the liquid drug to determine a number of times a portion of the
drug is delivered and/or an amount of liquid drug remaining as
described herein, for example based on the movement of the arm
1108. The drug container 1112, like the drug container 1002, can
include a port for the liquid drug (not shown in FIG. 11).
[0057] FIG. 12 illustrates a second view of the ratchet drive
system 1100 depicted in FIG. 11. FIG. 11 can represent an isometric
view of the ratchet drive system 1100. FIG. 12 can represent a
corresponding side view of the ratchet drive system 1100. As shown
in FIG. 12, the pawl 1110 couples the arm 1108 to the rack 1102.
The drug container 1112 includes a reservoir 1202 for storing the
liquid drug. The reservoir 1202 can be defined in part by the
plunger 1104 and an end of the drug container (opposite to the
plunger 1104; not shown in FIG. 12). The end of the drug container
1112 can include a port or other opening allowing the liquid drug
stored in the reservoir 1202 to be expelled as the plunger 1104 is
advanced toward the end of the drug container 1112.
[0058] FIG. 13 illustrates the ratchet drive system 1100 during
delivery of the liquid drug. As shown in FIG. 13, the arm 1108
extends in a direction 1302. As a result, the rack 1102 and plunger
1104 are advanced in a direction 1304 as shown. The advancement of
the plunger 1104 further into the drug container 1112 can cause a
portion of the liquid drug stored in the reservoir 1202 to be
expelled from the drug container 1112. The arm 1108 can be sized
such that extension of the arm 1108 in the direction 1302
corresponds to a desired amount of the liquid drug being expelled
(e.g., a single dose or a portion thereof). As described herein,
the length of the arm 1108 can be limited such that only a desired
amount of the liquid drug is expelled by moving the rack 1102 and
the plunger 1104 by the amount the arm 1108 is extended. Runaway
operation and over-delivery of the liquid drug can therefore be
avoided in case of a system failure (e.g., power loss) of the OBDS
in which the ratchet drive system 1100 is incorporated since
further movement of the rack 1102 by the arm 1108 is
restricted.
[0059] After the arm 1108 is extended by the set amount, the arm
1108 and the rack 1102 can come to a rest. The controller can track
the movement of the arm 1008 and can maintain a count of the number
of times the arm 1108 is extended to expel the liquid drug. The
amount the arm 1108 is extended can correspond to any desired
amount of drug to be delivered to a user including, for example, a
single dose of the liquid drug, or a portion thereof.
[0060] FIG. 14 illustrates the ratchet drive system 1100 initiating
a return to its initial or idle state. As shown in FIG. 14, the arm
1108 is a moved in a direction 1402 back toward the power source
1106. The pawl 1110 is shaped so as to rotate in a direction 1404
as the arm 1108 is moved in the direction 1402. As a result, the
pawl 1110 is disengaged from the rack 1102. The rack 1102 therefore
does not move and remains stationary as the arm 1108 is moved
backwards (e.g., in the direction 1402). In various embodiments,
the pawl 1110 can be controlled to rotate in the direction 1404 to
facilitate disengagement from the rack 1102. The arm 1108 can be
retracted back to an original position corresponding to the
position of the arm 1108 prior to activation.
[0061] FIG. 15 illustrates the ratchet drive system 1100
re-engaging the rack 1102. As shown in FIG. 15, the arm 1108 is in
close proximity to the power source 1106. When the arm 1108 stops
moving, the pawl 1110 rotates in a direction 1502 to re-engage the
rack 1102. Once the pawl 1110 re-engages the rack 1102, the ratchet
drive system 1110 can be re-activated to a deliver a subsequent
amount of the liquid drug.
[0062] In various embodiments, the stroke of the arm 1108 can be
greater than a length of one tooth on of the rack 1102 so as to
provide clearance for the pawl 1110 to rotate as described herein
without hitting a tooth of the rack 1102. In various embodiments,
the rotational movement of the pawl 1110 and/or the linear movement
of the pawl 1110 can be passive movements, as the angle of the rack
1102 can push the pawl 1110 out of the way. In such embodiments,
the pawl 1110 can be spring loaded, for example, and biased to be
in the engaged position as shown in FIG. 15. As described above, in
various other embodiments, the pawl 1110 can be actively rotated as
desired for retraction, using a separate power source for
example.
[0063] As described herein, the ratchet drive system 1100 can also
prevent overdose situations that can occur with conventional drive
systems for drug delivery devices by restricting linear movement
and using multiple actuations cycles to deliver one or more doses
of the liquid drug. For example, if the power source 1108 suddenly
and/or catastrophically fails at any time (e.g., during delivery of
a dose and/or when the arm 1108 is being extended), then the length
of the arm 1108 (e.g., maximum extension of the arm 1108) can
restrict the amount by which the rack 1102 and the plunger 1104 can
move. As a result, delivery of any further drug can be
prevented.
[0064] FIG. 16 illustrates a fourth exemplary ratchet drive system
1600. The ratchet drive system 1600 can be a variation of the
ratchet drive system 1100. As with the ratchet drive systems 100,
800, and 1100, the ratchet drive system 1600 can be used in an OBDS
as described herein and can provide the same benefits as the
ratchet drive system 1600. The ratchet drive system 1600 can
include the rack 1102, the plunger 1104, the power source 1106, the
arm 1108, a pawl 1606, and the drug container 1112. The ratchet
drive system 1600 can operate in a substantially similar manner as
the ratchet system 1100 with the exceptions described herein.
[0065] As shown in FIG. 16, the pawl 1606 can be coupled to the arm
1108. As opposed to rotating like the pawl 1110, the pawl 1606 can
be coupled to the arm 1108 and arranged to move up and down (e.g.,
towards and away from the rack 1102) to engage and disengage from
the rack 1102 as described further herein.
[0066] FIG. 16 illustrates the ratchet drive system 1600 during
delivery of the liquid drug. As shown in FIG. 16, the arm 1108
extends in a direction 1602 and the pawl 1606 is engaged with the
rack 1102. As a result, the rack 1102 and the plunger 1104 are
advanced in a direction 1604 as shown. The advancement of the
plunger 1104 further into the drug container 1112 can cause a
portion of the liquid drug stored in the reservoir 1202 to be
expelled from the drug container 1112 as described above in
relation to the ratchet drive system 1100. Once the arm 1108 is
extended by a desired or predetermined amount, the arm 1108 and the
rack 1102 can come to rest.
[0067] FIG. 17 illustrates the ratchet drive system 1600 initiating
a return to its initial or idle state. As shown in FIG. 17, the arm
1108 is moved in a direction 1702 back toward the power source
1106. The pawl 1606 can move downward in a direction 1704 as the
arm 1108 is moved in the direction 1702. As a result, the pawl 1606
is disengaged from the rack 1102. The rack 1102 therefore does not
move and remains stationary as the arm 1108 is moved backwards
(e.g., in the direction 1702). In various embodiments, the movement
of the pawl 1606 in the direction 1704 can be passive, for example,
based on a shape of the pawl 1606 and interaction with the teeth of
the rack 1102. In various embodiments, the pawl 1606 can be spring
loaded to enable disengagement and re-engagement of the pawl 1606
with the rack. In various embodiments, the pawl 1606 can be
controlled, for example by a power source, to move in the direction
1704.
[0068] FIG. 18 illustrates the ratchet drive system 1600
re-engaging the rack 1102. As shown in FIG. 18, the arm 1108 is in
close proximity to the power source 1106. When the arm 1108 stops
moving, the pawl 1606 can move upwards in a direction 1802 to
re-engage the rack 1102. Once the pawl 1606 re-engages the rack
1102, the ratchet drive system 1600 can be re-activated to a
deliver a subsequent predetermined amount of the liquid drug. As
described above, the movement of the pawl 1606 (e.g., in the
direction 1802) can be passive movement or can be actively
controlled.
[0069] The following examples pertain to additional
embodiments:
[0070] Example 1 is a ratchet drive system comprising a ratchet
gear, a lead screw coupled to the ratchet gear, an end of the lead
screw coupled to a plunger positioned in a drug container, a
ratchet carrier positioned around the ratchet gear, a first pawl
coupled to the ratchet carrier and a second pawl coupled to the
ratchet carrier, the first and second pawls configured to
selectively engage the ratchet gear, and a first carrier stop
configured to restrict rotation of the ratchet carrier in a first
direction.
[0071] Example 2 is an extension of Example 1 or any other example
disclosed herein, comprising a second carrier stop configured to
restrict rotation of the ratchet carrier in a second, opposite
direction.
[0072] Example 3 is an extension of Example 2 or any other example
disclosed herein, wherein the first and second pawls are configured
to engage the ratchet gear when the ratchet carrier is rotated in
the first direction, thereby coupling the ratchet carrier to the
ratchet gear.
[0073] Example 4 is an extension of Example 3 or any other example
disclosed herein, wherein the ratchet gear and the lead screw are
configured to rotate in the first direction when the ratchet
carrier is rotated in the first direction.
[0074] Example 5 is an extension of Example 4 or any other example
disclosed herein, wherein the lead screw is configured to move in a
linear direction when the ratchet carrier is rotated in the first
direction, the linear direction parallel to an axis of rotation of
the ratchet carrier.
[0075] Example 6 is an extension of Example 5 or any other example
disclosed herein, wherein the lead screw is configured to move the
plunger in the linear direction and further into the drug container
when the ratchet carrier is rotated in the first direction.
[0076] Example 7 is an extension of Example 6 or any other example
disclosed herein, wherein the plunger is configured to expel a
portion of a liquid drug stored in the drug container when moved in
the linear direction.
[0077] Example 8 is an extension of Example 7 or any other example
disclosed herein, wherein a predetermined dose of the liquid drug
is expelled from the drug container when the ratchet carrier is
rotated in the first direction from an initial position
corresponding to the second carrier stop to a final position
corresponding to the first carrier stop.
[0078] Example 9 is an extension of Example 8 or any other example
disclosed herein, wherein the first and second carrier stops are
displaced by approximately 180 degrees.
[0079] Example 10 is an extension of Example 8 or any other example
disclosed herein, wherein the first carrier stop is configured to
prevent the ratchet carrier from rotating further in the first
direction.
[0080] Example 11 is an extension of Example 8 or any other example
disclosed herein, wherein the first and second pawls are configured
to disengage the ratchet gear when the ratchet carrier is rotated
in the second direction, thereby decoupling the ratchet gear from
the ratchet carrier.
[0081] Example 12 is an extension of Example 11 or any other
example disclosed herein, wherein the ratchet gear and the lead
screw are configured to remain stationary when the ratchet gear is
rotated in the second direction.
[0082] Example 13 is an extension of Example 11 or any other
example disclosed herein, wherein the ratchet carrier is rotated in
the second direction to return to the initial position to reset the
ratchet drive system.
[0083] Example 14 is an extension of Example 13 or any other
example disclosed herein, wherein the first and second pawls are
configured to re-engage the ratchet gear when the ratchet drive
system is reset.
[0084] Example 15 is an extension of Example 13 or any other
example disclosed herein, further comprising a power source for
rotating the ratchet carrier.
[0085] Example 16 is an extension of Example 51 or any other
example disclosed herein, wherein the ratchet gear comprises gear
teeth position around a perimeter of the ratchet carrier, wherein
the ratchet drive system further comprises a gear coupled to the
gear teeth of the ratchet carrier and coupled to the power source,
wherein the power source rotates the ratchet carrier by rotating
the gear.
[0086] Example 17 is an extension of Example 16 or any other
example disclosed herein, further comprising a controller, the
controller configured to control operation of the power source and
rotation of the ratchet carrier.
[0087] Example 18 is an extension of Example 17 or any other
example disclosed herein, wherein the first and second carrier
stops each include a sensor configured to detect when the ratchet
carrier is in the final position and the initial position,
respectively.
[0088] Example 19 is an extension of Example 18 or any other
example disclosed herein, wherein each sensor is configured to
transmit a signal to the controller to indicate at least one of the
final position and the initial position of the ratchet carrier.
[0089] Example 20 is an extension of Example 18 or any other
example disclosed herein, wherein the controller is configured to
maintain a count of a number of predetermined doses of the liquid
drug that have been delivered based on the signals transmitted by
the sensors.
[0090] Example 21 is an extension of Example 1 or any other example
disclosed herein, wherein the drive system is part of an on-body
delivery system (OBDS).
[0091] Example 22 is a method comprising rotating a ratchet carrier
in a first direction from an initial position to a final position,
rotating a ratchet gear in the first direction based on rotating
the ratchet carrier, rotating a lead screw in the first direction
based on rotating the ratchet gear, moving the lead screw in a
linear direction parallel to an axis of rotation of the lead screw
based on rotating the lead screw, the lead screw coupled to a
plunger positioned in a drug container holding a liquid drug, and
moving the plunger in the linear direction further into the drug
container based on moving the lead screw, thereby expelling a dose
of the liquid drug from the drug container.
[0092] Example 23 is an extension of Example 22 or any other
example disclosed herein, further comprising restricting rotation
of the ratchet carrier beyond the final position based on a
position of a first carrier stop.
[0093] Example 24 is an extension of Example 23 or any other
example disclosed herein, further comprising detecting the final
position of the ratchet carrier based on a sensor of the first
carrier stop.
[0094] Example 25 is an extension of Example 24 or any other
example disclosed herein, further comprising maintaining a count of
a number of doses of the liquid drug expelled based on detecting
the final position of the ratchet carrier.
[0095] Example 26 is an extension of Example 25 or any other
example disclosed herein, further comprising rotating the ratchet
gear in a second direction opposite the first direction from the
final position to the initial position.
[0096] Example 27 is an extension of Example 26 or any other
example disclosed herein, further comprising decoupling the ratchet
carrier from the ratchet gear prior to rotating the ratchet gear in
the second direction, thereby preventing the ratchet gear and the
lead screw from rotating in the second direction.
[0097] Example 28 is an extension of Example 27 or any other
example disclosed herein, further comprising restricting rotation
of the ratchet carrier beyond the initial position based on a
position of a second carrier stop.
[0098] Example 29 is an extension of Example 28 or any other
example disclosed herein, further comprising detecting the initial
position of the ratchet carrier based on a sensor of the second
carrier stop.
[0099] The following examples pertain to further additional
embodiments:
[0100] Example 1 is a ratchet drive system, comprising a power
source, an arm coupled to the power source, a pawl coupled to an
end of the arm, a rack coupled to the arm through the pawl, and a
plunger coupled to the end of the rack, the plunger positioned
within a drug container storing a liquid drug.
[0101] Example 2 is an extension of Example 1 or any other example
disclosed herein, the power source configured to cause the arm to
extend in a first direction, thereby moving the rack in the first
direction.
[0102] Example 3 is an extension of Example 2 or any other example
disclosed herein, wherein the plunger is configured move in the
first direction further into the drug container when the rack is
moved in the first direction.
[0103] Example 4 is an extension of Example 3 or any other example
disclosed herein, wherein a portion of the liquid drug is expelled
from the drug container when the plunger is moved in the first
direction.
[0104] Example 5 is an extension of Example 4 or any other example
disclosed herein, wherein a predetermined dose of the liquid drug
is expelled from the drug container when the arm is moved in the
first direction from an initial position to a final position.
[0105] Example 6 is an extension of Example 5 or any other example
disclosed herein, wherein the final position corresponds to a
maximum extension of the arm.
[0106] Example 7 is an extension of Example 6 or any other example
disclosed herein, wherein the pawl is configured to disengage the
rack after the arm is in the final position.
[0107] Example 8 is an extension of Example 7 or any other example
disclosed herein, wherein the power source is configured to cause
the arm to move in a second, opposite direction after the arm is in
the final position.
[0108] Example 9 is an extension of Example 8 or any other example
disclosed herein, wherein the rack and the plunger are configured
to remain stationary when the arm moves in the second
direction.
[0109] Example 10 is an extension of Example 9 or any other example
disclosed herein, wherein the ratchet drive system is reset when
the arm moves in the second direction to return to the initial
position.
[0110] Example 11 is an extension of Example 10 or any other
example disclosed herein, wherein the pawl is configured to
re-engage the rack when the ratchet drive system is reset.
[0111] Example 12 is an extension of Example 11 or any other
example disclosed herein, further comprising a controller for
activating movement of the arm in the first direction and the
second direction based on control of the power source.
[0112] Example 13 is an extension of Example 12 or any other
example disclosed herein, wherein the power source is a motor.
[0113] Example 14 is an extension of Example 12 or any other
example disclosed herein, wherein the power source is a linear
actuator.
[0114] Example 15 is an extension of Example 12 or any other
example disclosed herein, wherein the controller is configured to
maintain a count of a number of predetermined doses of the liquid
drug that have been expelled based on the movement of the arm.
[0115] Example 16 is an extension of Example 1 or any other example
disclosed herein, wherein the drive system is part of an on-body
delivery system (OBDS).
[0116] Example 17 is a method comprising extending an arm in a
first direction from an initial position to a final position,
moving a rack in the first direction based on extending the arm,
the rack coupled to a plunger positioned in a drug container
holding a liquid drug, and moving the plunger in the first
direction further into the drug container based on moving the rack,
thereby expelling a dose of the liquid drug from the drug
container.
[0117] Example 18 is an extension of Example 17 or any other
example disclosed herein, further comprising detecting the final
position of the arm.
[0118] Example 19 is an extension of Example 18 or any other
example disclosed herein, further comprising maintaining a count of
a number of doses of the liquid drug expelled based on detecting
the final position of the arm.
[0119] Example 20 is an extension of Example 19 or any other
example disclosed herein, further comprising coupling the arm to
the rack with a pawl.
[0120] Example 21 is an extension of Example 20 or any other
example disclosed herein, further comprising moving the pawl to
decouple the arm from the rack after the arm is extended to its
final position.
[0121] Example 22 is an extension of Example 21 or any other
example disclosed herein, further comprising rotating the pawl to
decouple the arm from the rack after the arm is extended to its
final position.
[0122] Example 23 is an extension of Example 21 or any other
example disclosed herein, further comprising moving the pawl in a
direction away from the rack to decouple the arm from the rack
after the arm is extended to its final position.
[0123] Example 24 is an extension of Example 21 or any other
example disclosed herein, further comprising moving the arm in a
second direction opposite the first direction to retract the arm to
the initial position from the final position.
[0124] Example 25 is an extension of Example 24 or any other
example disclosed herein, further comprising restricting movement
of the rack and the plunger in the second direction.
[0125] Certain embodiments of the present invention were described
above. It is, however, expressly noted that the present invention
is not limited to those embodiments, but rather the intention is
that additions and modifications to what was expressly described
herein are also included within the scope of the invention.
Moreover, it is to be understood that the features of the various
embodiments described herein were not mutually exclusive and can
exist in various combinations and permutations, even if such
combinations or permutations were not made express herein, without
departing from the spirit and scope of the invention. In fact,
variations, modifications, and other implementations of what was
described herein will occur to those of ordinary skill in the art
without departing from the spirit and the scope of the invention.
As such, the invention is not to be defined only by the preceding
illustrative description.
* * * * *