The present invention relates to infusion devices and more particularly to such devices that enable liquid medicaments to be conveniently and safely self-administered by a patient. One liquid medicament that is often self-administered by a patient is insulin, and for ease of description, the administration of insulin is generally used herein for exemplary purposes although the invention should not be limited by that exemplary use.
Administration of insulin has traditionally been accomplished using a syringe. Recently, needle carrying pen-like devices have also been employed for this purpose. Both forms of insulin administration require the patients to stick themselves each time they inject insulin, often many times a day. Additionally, a new clean needle must be mounted on the device each time they are used, and disposed of after each use, creating the additional problem of having the “sharps” with them whenever the patient needs to administer insulin, and to safely dispose of them after each use. Thus, these traditional forms of insulin administration have been a rather pervasive intrusion in the lives and routines of the patients who have had to adopt and employ them.
More recently, insulin pumps attached by tubing to an infusion set mounted on the patient's skin have been developed as an alternative form of insulin administration. Such pumps may be controlled by a programmable remote electronic system employing short range radio communication between a control device and electronics that control the pump. While such devices may involve fewer needle sticks, they are expensive to manufacture. They are also complex to operate and cumbersome and awkward to wear. Further, the cost of such devices can be many times the daily expense of using a traditional injection means such as a syringe or an insulin pen.
Devices of the type mentioned above also require a significant amount of training to control and thus use the devices. Great care in programming the devices is required because the pumps generally carry sufficient insulin to last a few days. Improper programming or general operation of the pumps can result in delivery of an excessive amount of insulin which can be very dangerous and even fatal.
Many patients are also reluctant to wear a pump device because they can be socially awkward. The devices are generally quite noticeable and can be as large as a pager. Adding to their awkwardness is their attachment to the outside of the patients clothes and the need for a catheter like tubing set running from the device to an infusion set located on the patient's body. Besides being obvious and perhaps embarrassing, wearing such a device can also be a serious impediment to many activities such as swimming, bathing, athletic activities, and many activities such as sun bathing where portions of the patient's body are necessarily uncovered.
In view of the above, a more cost effective and simple device has been proposed whereby an injection system is discreetly attached directly to the skin of the patient. One example of such a device is described in detail in U.S. application Ser. No. 12/147,283 filed Jun. 26, 2008 and titled DISPOSABLE INFUSION DEVICE WITH REDUNDANT VALVED SAFETY, which application is owned by the assignee of this application and incorporated herein by reference in its entirety. Such a device may be attached to the patient under the patient's clothing to deliver insulin into the patient by the manual pumping of small doses of insulin out the distal end of a temporarily indwelling cannula that is made a part of the pump device. The device may be made quite small and, when worn under the clothes, entirely unnoticeable in most social situations. It may still carry sufficient insulin to last a patient several days. It can be colored to blend naturally with the patient's skin color so as not to be noticeable when the patient's skin is exposed. As a result, insulin for several days may be carried by the patient discreetly, and conveniently applied in small dosages after only a single needle stick. For another description of devices of this type, reference may also be had to co-pending application Ser. No. 11/906,130, filed on Sep. 28, 2007 for DISPOSABLE INFUSION DEVICE WITH DUAL VALVE SYSTEM, which application is owned by the assignee of this application and hereby incorporated herein by reference in its entirety.
Although relatively discrete, the patient may have a reason to remove the system entirely. Likewise, if the drug delivery system is accidentally dislodged from the patient, it would be advantageous to be able to salvage the medicament and pump, and to replace only the minimum amount of the system. Where the pump, insulin supply and cannula are integral and non-separable units, removing just the pump or just the insulin, or adding a different liquid medicament is not generally feasible. Sometimes it would be advantageous to be able to remove the pump unit, the insulin reservoir, or the entire device, and to reassemble and use parts of the drug delivery system. Additionally, since the portion of system that contains the cannula needs to be removed and reinstalled every three days pursuant to current medical and regulatory practice, it would be advantageous to be able to remove the other portions of the drug delivery system from the portion with the cannula, and reattach them to a new cannula containing portion, thus avoiding replacing them with every use.
Further, it would be advantageous if the device was configured to utilize commercially available reservoirs or cartridges. For example, glass cartridges are presently used for insulin injection pens, which are readily available to the patient with a prescription. It would be beneficial to some patients to combine the availability of these cartridges with a discreet device that removes the attendant problems of a syringe-pen. Such a device would also decrease the attendant manufacturing costs of a device that utilizes proprietary reservoirs. More importantly, it would mitigate the inconvenience to the patient of filling or refilling a reservoir and the attendant problems associated with the patient performing that task.
Therefore there is a need for an invention that makes it possible to have a small, simple and discreet drug delivery system and yet be able to remove various components of the drug delivery system from each other, and to reattach them to each other without the need to discard the entire system.
In one embodiment, a drug infusion system comprises a base having a cannula well arranged to receive a cannula that conducts the drug to beneath a wearer's skin. The base further includes a base surface arranged to attach to the skin of the wearer. The base includes the cannula well and is arranged to dispose a cannula to extend from the base surface to beneath the wearer's skin. The base further includes an inlet arranged to receive the drug, a conduit that conducts the drug from the inlet to the cannula well, and a first self sealing penetrable barrier moveable with respect to the inlet. The system further includes a reusable drug dispenser removably attachable to the base and having a second self sealing penetrable barrier, a reservoir arranged to hold the drug, and a pump that pumps the drug to the second self sealing penetrable barrier. The first and second self sealing penetrable barriers are arranged to engage each other and to be penetrated by the inlet of the base when the reusable dispenser is attached to the base to form a antiseptic connection between the cannula well and the reservoir.
The inlet may comprise a needle. The system may further comprise a latch assembly that releasably holds the reusable dispenser on the base. The latch assembly may include a male/female clasp arrangement. The clasp arrangement and first and second sealing penetrable barrier may be arranged such that as the male/female clasp arrangement engages, the first and second self sealing penetrable barriers engage each other and are penetrated by the needle to discard the entire system.
The pump may be any one of acceptable drug delivery pumps which may include, for example, a piston pump, a peristaltic pump, a screw pump, a membrane pump, a metering device, and a gas driven positive displacement pump. The system may further comprise a cannula set including a receiving pike and the cannula. The receiving pike may be arranged to be received within the cannula well in fluid communication with the conduit, whereby a fluid connection is formed from the cannula through the conduit to the reservoir. The cannula set may further include a top sealing member. The cannula set may further include a port aligned with the cannula that facilitates placement of the cannula set into the cannula well and a port cover that blocks the port to preclude direct access to the cannula through the port after the cannula set is received within the cannula well. The cannula may be arranged to be deployed beneath the wearer's skin with a drive needle that extends through the port and carries the cannula into the deployed position and the cover may be arranged to block the port upon withdrawal of the needle from the cannula set after deployment of the cannula. The port cover may be formed of resilient material and be arranged to spring over and block the port responsive to the drive needle being withdrawn from the port.
The base may include a guide that guides the reusable dispenser into attachment on the base. The base lower surface may include an adhesive that attaches the base to the wearer's skin. The base may be coextensive with the reusable dispenser when the reusable dispenser is attached to the base. The reusable dispenser may include an inlet cavity adjacent the second self sealing penetrable barrier that receives the inlet of the base when the reusable dispenser is attached to the base. The inlet cavity may be arranged to receive the drug from the reservoir and provide the drug to the inlet of the base. The reusable dispenser may include a pair of actuators operatively associated with the pump for causing the pump to pump the drug form the reservoir to the cannula upon concurrent actuation of the actuators.
The inlet of the base may have a distal end that penetrates the first and second self sealing penetrable barriers when the reusable dispenser is attached to the base. The first self sealing penetrable barrier may be moveable with respect to the inlet of the base and the base may further include a biasing element that urges the first self sealing penetrable barrier against the second self sealing penetrable barrier when the reusable dispenser is attached to the base.
The system may further comprise a vent immediately adjacent the second self sealing penetrable barrier. The vent may comprise a hydrophobic vent covered by a one-way valve that allows the passage of air out the vent, does not allow liquid such as liquid medicament out the vent, and after the pathway is vented, does not allow air back into the fluid pathway.
The reusable portion may comprise a separate reservoir unit that holds the drug to be delivered. The reservoir unit may be engageable with the dispenser such as a pump portion, and both portions may be releasably secured to the base. The reusable portion may further comprise at least one latch that maintains the dispenser and reservoir unit in engagement. The at least one latch may comprise a latching projection and a projection receiving slot.
The latching projection may be carried by the dispenser and the projection receiving slot may be formed in the reservoir unit. The system may further comprise an antiseptic coupling between the dispenser and reservoir unit.
An alternative embodiment for a drug infusion system is also disclosed. The alternative embodiment comprises a base configured to receive a cannula that delivers a drug to beneath a wearer's skin. The base further includes a base surface arranged to attach to the skin of the wearer and is arranged to dispose the cannula to extend from the base surface to beneath the wearer's skin. The device further comprises a reusable drug dispenser removably attachable to the base. The reusable drug dispenser has a pump unit configured to establish fluid communication between a removably attachable drug reservoir and the cannula, whereby the pump unit pumps the drug to the wearer upon activation of the pump by the wearer.
The pump unit may further comprise an inlet configured to contact the drug within the reservoir, and the inlet may be a needle. The pump unit may also comprise a receiving unit configured to receive the reservoir. Such a receiving unit may be tubular to accommodate a cylindrical reservoir. The receiving unit may comprise a cavity configured to hold the reservoir. The pump unit may comprise an encasing unit configured to hold the reservoir, and such an encasing unit may be positioned to one side of the pump unit, thereby allowing a lower profile.
In another embodiment, a drug infusion assembly comprises a base including a base surface arranged to attach to the skin of a wearer. The base includes a cannula arranged to extend from the base surface to beneath the wearer's skin and an inlet in fluid communication with the cannula. The infusion assembly further comprises a pump unit removably attachable to the base. The pump unit has a cavity and a latch assembly within the cavity. The cavity is arranged to receive a cartridge reservoir therein and the latch assembly is arranged to releasably lock the cartridge reservoir within the cavity. The pump unit is configured to establish fluid communication between the releasably locked cartridge reservoir and the inlet of the base and to pump a liquid medicament stored in the cartridge reservoir to the inlet of the base and the cannula upon activation by the wearer.
The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with further features and advantages thereof, may best be understood by making reference to the following description taken in conjunction with the accompanying drawings, in the several figures of which like reference numerals identify identical elements, and wherein:
Referring now to
The base portion 40 includes a base surface 41 which preferably is coated with an adhesive for attaching the base portion 40 to the skin of a wearer in need of the drug, such as insulin, to be delivered by the system 20. To that end, the base 40, in a manner to be fully described herein after, is arranged to receive a cannula 100 which, when deployed, extends from the base surface 41 to beneath the skin of the wearer for subcutaneous delivery of the drug. The reusable dispenser portion includes a reservoir (not shown) for containing the drug and a pump (not shown) that, when actuated, pumps the drug from the reservoir to the cannula for delivery. As will be seen subsequently, when the base 40 and reusable portion 60 are joined together, a coupling arrangement provides an antiseptic connection there between. Also, the cannula 100 is a part of a cannula set which may be replaced in the base 40 when the reusable portion 60 is removed.
To actuate the pump, the reusable portion 60 includes a pair of actuator buttons 64 and 66. Preferably, the actuator buttons are arranged with the pump and other operative internal components of the reusable portion 60 so that concurrent depression of the actuator buttons 64 and 66 is required to actuate the pump. Infusion devices having such functionality are fully described, for example, in copending application Ser. No. 12/147,314 filed Jun. 26, 2008 for DISPOSABLE INFUSION DEVICE WITH PRIME INDICATOR, which application is assigned to the assignee of the present invention and incorporated herein by reference in its entirety. The pump for this or any of the subsequent embodiments may be any one of acceptable drug delivery pumps which may include, for example, a piston pump, a peristaltic pump, a screw pump, a membrane pump, a metering device, and a gas driven positive displacement pump.
The base 40 and reusable portion 60 are releasably fixed together by a latch assembly 120. In accordance with this embodiment, the latch assembly 120 includes a male part including projections 122 carried by the reusable portion 60 that are snappingly received within slots 124 of the base 40. A further snap-action latch 126 is provided at the distal end of the system 20 to complete the confinement of the reusable portion 60 on the base 40.
Alternatively, as shown in
In use, the wearer pushes the base 40′ against the wearer's skin, such that the needle 107 penetrates the skin. The cannula 106 is carried by the needle 107 through the tissue to beneath the skin. During this process and substantially simultaneously, the adhesive layer of the base 40′ will make contact with and adhere to the skin.
The perspective views of
The base 40 further includes relieved surfaces 46 that form resulting shoulders 48 and 50. The shoulders 48 and surfaces 46 form guides to guide the reusable portion 60 into proper alignment with the base 40 as they are joined together. The shoulders 50 provide a stop which is engaged when the base 40 and reusable portion 60 are finally snapped together. The opening 44 may also be formed in its proximal portion as a channel that mates with coupling projection 74 as shown in
As best seen in
The cannula set 102 and details of its deployment will now be described with particular reference to
The carrier further includes a port 110 through which a deployment needle (not shown) may be inserted. Prior to cannula deployment, the deployment needle extends through the port 110, through a passage 112, and through the cannula 100. The use of a deployment needle to subcutaneously place a cannula is described in greater detail in application Ser. No. 12/147,295 titled DISPOSABLE INFUSION DEVICE WITH AUTOMATICALLY RELEASABLE CANNULA DRIVER concurrently owned by applicant and incorporated herein in its entirety. The cannula set 102 is thus carried on the deployment needle. When the cannula set is deployed, the needle is retracted leaving the cannula set deployed as shown in
To preclude direct access to the cannula 100 through the port 110 after deployment needle removal, the cannula set further includes a port cover 114. The port cover is preferably formed of resilient material and is arranged to spring over and block the port responsive to the drive needle being withdrawn from the port. Such a port cover is fully described, for example in co-pending application Ser. No. 12/147,306 filed Jun. 26, 2008 for DISPOSABLE INFUSION DEVICE WITH CANNULA PORT COVER, which application is assigned to the assignee of the present invention and incorporated herein by reference in its entirety. The port cover 114 together with a top 116 of the carrier 104 form a top sealing member of the carrier 104.
Here the base 40 may be seen to include an inlet chamber 140. Extending through the inlet chamber 140 is a needle 142 that forms an inlet to the base 40. The needle 142 has a sharpened distal tip 143. The distal end of the inlet chamber 140 is sealed with a self sealing, penetrable, barrier or septum 144. A spring 146 urges the septum 144 in the distal direction. The reusable portion 60, in turn, includes a conduit 76 within the coupling 74. The coupling is sealed with a self sealing, penetrable, barrier or septum 78. Immediately adjacent the septum 78 is a one-way valve 77 to vent the conduit 76. This permits the drug, such as insulin, to be primed within the conduit so as to be in contact with the septum to eliminate air bubbles which might otherwise form.
When it is necessary to remove the reusable portion 60 from the base 40, as the reusable portion 60 is pulled from the base 40, the compressed spring 146 forces the septum 144 distally until it once again seals the inlet chamber 140 as shown in
An alternative (not shown) to the small wiper 246 illustrated would be a larger block of compressible foam or cotton impregnated with antiseptic solution, the cotton or foam contained with the bore 140 and located so that it would extend slightly back from the tip of the needle 142 to pipe most of the needle except the tip with antiseptic solution whenever the septum 144 is forced out beyond the tip of the needle 142 by spring 146.
The base 340 may be similar to the base 40, previously described. To that end, it may also be arranged to receive a cannula set in its head portion 342 to establish fluid communication with the pump of the pump unit 360 in a manner as previously described.
The pump unit 360 is maintained on the base 340 by way of snap action latches 322 of the type previously described. The pump unit 360 includes actuator buttons 364 and 366 which, as previously described with respect to previous embodiments, are preferably arranged to cause drug delivery upon the concurrent depression of the actuator buttons 364 and 366.
The reservoir unit 380 is maintained on the base 340 by way of side snap action latches 382. The reservoir unit 380 is preferably prefilled prior to deployment in the system 320. More particularly, the reservoir unit 380 may be provided as a stand alone item from a drug manufacturer under prescription and not require any special handling by the patient except for its deployment on the base 340 in engagement with the pump unit 360. Alternatively, the reservoir unit may also be deployed on the reusable drug dispenser portion.
Antiseptic coupling of the base 340 and pump unit 360 and of the reservoir unit 380 and pump unit 360 may each be accomplished by employing dual septa and penetrating inlet needles as previously described. However, a vent need not be required for the antiseptic coupling of the reservoir unit 380 and the pump unit 360 because the reservoir unit may be manufactured to have the liquid drug, such as insulin, already immediately adjacent its sealing septum to prevent air bubble formation.
A more detailed description of the attachment mechanism of the reservoir portion and the pump portion may be seen in
The pump portion 412 contains a pump 414 shown here in representative form. As stated earlier, any suitable pump may be employed. The pump portion contains on its distal end 416 all the mechanisms necessary to mate and form a detachable fluid connection with the base as described in detail above. In addition it contains a piercing needle 418 in an inlet bore 420. Located at the end of the bore is a sealing septum 422. A biasing mechanism, such as spring 424 urges the septum outward within the inlet bore 420. The septum is movable with the bore, and when the two septa 406,422 are urged against each other, the inlet bore septa slides back over the piercing needle 418 which simultaneously pierces the reservoir septum and forms a fluid connection between the reservoir and the pump.
As with the previous connection between the reusable portion and the base, an antiseptic member may be provided within the bore and surrounding the needle 418 to wipe the needle between connections. It is also to be noted that the previous description of the connection between the reservoir portion and the pump portion illustrated a side releasable snap configuration similar to the snap attachment between the reusable portion and the base, and in the embodiment shown in
The reservoir portion may be provided with a collapsible reservoir and prefilled by the manufacturer, in which case no priming mechanism is needed. If it is filled by the user soon before use, as is described in detail in the applications incorporated by reference herein, a simple mechanism of venting would be required. A vent comprised of a hydrophobic vent covered with a one way valve as described for the reusable unit and located on the outlet bore near the septum, in combination with a method of applying pressure to the reservoir such as a pressure button 425 would suffice.
In another embodiment, the reservoir may be a commercially available cartridge, such as an insulin cartridge. Such cartridges may be specially manufactured to fit the device, or may be of the type that is presently commercially available for syringe-pen injection units.
One possible embodiment using a commercially available cartridge (either pre-loaded or user loaded) is shown in
Needle 528 is in fluid communication with a pumping mechanism 524, which can be any of the pumping mechanisms previously described. The pumping mechanism (also called a pump) in turn is in fluid communication with a cannula (not shown).
In use, the user inserts reservoir 510 (if the pump unit is not already pre-loaded) into the receiving unit 522 with sufficient force to pierce the septum 516. Alternatively, the septum 516 may be pierced by the needle 528 by user activation after the user inserts it into the receiving unit. In some embodiments, it may be desirable that after inserting and securing a first reservoir, the pump unit is rendered unable to receive any subsequent reservoirs. This would make the reusable pump unit usable for the contents of just one reservoir. Once the needle 528 has pierced through the septum 516, the fluid contained within the reservoir is drawn via the needle 528, through the pumping mechanism 524 and out through the cannula (not shown) into the patient. The pumping mechanism 524 may be actuated by the concurrent depression of actuator buttons 513 and 515 (
In this and subsequent embodiments, the pre-filled cartridge 510 may comprise a plunger element 517 as best seen in
An alternative embodiment wherein a currently commercially available cartridge is employed as a reservoir is shown in
As shown in
As previously described in connection with
The penetrating inlet needle 628 is disposed in the receiving unit 625. As in previous embodiments, needle 628 is configured to pierce the septum 516 of the reservoir 510. In this embodiment, receiving unit 625 might be just the needle 628 anchored into the rest of the device. Alternatively, it may comprise the needle 628 and a suitable covering for the needle; for example, a tube, a hood or other such suitable sheath, to ensure that a user does not come into contact with the needle. Optionally, the cavity may be covered to provide a tubular opening into which the pre-filled glass cartridge may be located. Such an embodiment is contemplated in
As seen in
In use, the cartridge reservoir 510 is placed into the cavity 515 of the pumping unit 620 such that the septum 516 contacts and is penetrated by the penetrating inlet needle 628. The penetrating inlet needle 628 is in fluid communication with the pumping mechanism 622, which can be any of the pumping mechanisms previously described. The pumping mechanism in turn is in fluid communication with cannula 601 (
A further embodiment of the present invention is shown in
As in the previous embodiments, the pump unit comprises a receiving end 725 and a base-end 726. The receiving end 725 comprises a penetrating inlet needle 728, which is configured to penetrate the septum 516 of the reservoir. The base end 726 optionally comprises a spring 729 that is configured to push the plunger 517 of the device, thereby assisting with fluid entry into the needle 728.
As in the previous embodiments, in use, a user places the reservoir 510 into the pump unit 720 such that the septum 516 contacts and is pierced by the needle 728. The needle 728 is in fluid communication with the pumping mechanism 724 which draws fluid out of the reservoir 510 and into the cannula (not shown). In embodiments employing spring 729, the spring facilitates the drawing of fluid by the pump either by creating a continuous pressure throughout the course of use, or by helping overcome friction during the first actuation.
Referring now to
The base 802 includes a flexible web 808 which has an adhesive thereon to permit the base to be adhered to the skin of a patient. Covering the adhesive are two tabbed covers 810 and 812 including tabs 814 and 816 respectively. The tabs allow the covers to be readily peeled off to expose the adhesive just prior to deployment of the base against the patient's skin.
The base 802 further includes a receiving structure 820 secured to the top surface of the web 808. The receiving structure is arranged to detachably receive the pump unit 804 therein and includes a housing 822 arranged to receive and confine the forward end of the pump unit 804. The receiving structure further includes a latch 824 that releasably locks the pump unit 804 onto the base 802.
As will be seen subsequently, the base 808 includes a built-in cannula that extends from the adhesive side of the base 808. To facilitate deployment of the cannula as the assembly is adhered to the patient's skin, the base also includes an insertion needle of the type known in the art that extends through the cannula and carries it to a deployed position. As will also be seen subsequently, after the assembly is deployed, the insertion needle may be pulled out of the cannula and the housing. To that end, a handle 826 connected to the insertion needle is provided. After deployment of the assembly 800, the handled 826 may be grasped and pulled to remove the insertion needle.
The pump unit 804 includes an elongated cavity 830 for receiving the cartridge reservoir 806. The cavity, in accordance with this embodiment, has a tubular shape to correspond to the generally cylindrical shape of the cartridge reservoir 806 as may be noted in the drawing. The pump unit 804 may include a window 832, through which the amount of fluid left in the cartridge reservoir may be observed.
In accordance with prior embodiments, the pump unit 804 may contain any one of the pump mechanisms previously described herein. Actuation of the pump unit 804 may be achieved through a pair of actuating buttons 834 and 836. Preferably, the pump unit 804 is arranged so that concurrent depression of the actuating buttons 834 and 836 is required to actuate the pump unit 804.
In accordance with this embodiment, when the pump unit 804 is actuated, a bolus of the fluid carried in the cartridge reservoir 806 is dispensed out of on outlet port 838 of the pump unit 804. The outlet 838 is defined by a fitting 840 that makes a fluid tight seal with a corresponding inlet 842 (
The cartridge reservoir 806 may be of the type previously described. It includes a septum 850 at its distal end and a plunger 852 at its proximal end. The plunger, as in prior embodiments, is arranged to translate along the length of the cartridge reservoir as fluid is removed therefrom. The position of the plunger 852 may be seen through the window 832 to provide the wearer with an indication as to how much fluid is remaining in the cartridge reservoir 806.
Referring now to
As may be seen in
Eventually, as may be seen in
Preferably, the pump unit 804 includes cartridge receiving structures of the type previously described herein including a septum piercing needle to pierce the septum 850 and connect the cartridge reservoir 806 to a pump mechanism. The plunger 852 of the cartridge reservoir 806 protrudes slightly from the proximal end of the pump unit 804 and is ready to contact a spring of the base as previously described.
Next, the pump unit 804 is releasably joined with the base 802. As seen in
Now, priming of the fluid delivery system and removal of the adhesive covering tabbed covers 810 and 812 are required. This may be accomplished as shown in
To prime the fluid delivery system, the device 800 is actuated by depressing the actuator buttons 834 and 836 enough times to cause fluid to appear out of bore 886. When this occurs, it is known that the cannula and all of the fluid conduits from the cartridge reservoir to the distal end of the cannula are filled with fluid.
Of course, should the cartridge reservoir of a pump unit become empty before it is time to remove the base and cannula, the spent pump unit may be simply removed from the base and replaced with a new pump unit having a new cartridge reservoir. Still further, it is possible to reuse a pump unit. Hence, if a base need not be removed but a cartridge reservoir becomes empty, the pump unit may simply be removed from the base, the spent cartridge reservoir may be removed from the pump unit, a new cartridge reservoir may be inserted into the pump unit, and the reused pump unit equipped with the new cartridge reservoir may be releasably joined with the base.
While particular embodiments of the present invention have been shown and described, modifications may be made. It is therefore intended in the appended claims to cover all such changes and modifications which fall within the true spirit and scope of the invention as defined by those claims.
The present application claims the benefit of copending U.S. Provisional Patent Application Ser. No. 61/089,749, filed Aug. 18, 2008; the present application also claims the benefit of copending U.S. Provisional Patent Application Ser. No. 61/227,157, filed Jul. 21, 2009; all of the foregoing applications are incorporated herein by reference in their entireties.
Number | Date | Country | |
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61227157 | Jul 2009 | US | |
61089749 | Aug 2008 | US |
Number | Date | Country | |
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Parent | 12543352 | Aug 2009 | US |
Child | 15137204 | US |