Infusion device with pressurizable liquid medicament chamber
A disposable infusion device comprises a base arranged to adhere to a patient's skin, a cannula arranged to extend from the base to beneath the patient's skin to deliver a liquid medicament to the patient, and a source arranged to provide the cannula with a liquid medicament. The source includes a reservoir that holds the liquid medicament and a pressurizer that pressurizes the liquid medicament from within the reservoir to provide a flow of the liquid medicament to the cannula.
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This application claims priority to U.S. Provisional Application Ser. No. 60/782,941, filed on Mar. 16, 2006, which is incorporated by reference.
BACKGROUNDTight control over the delivery of insulin in both type I (usually juvenile onset) and type II (usually late adult onset), has been shown to improve the quality of life as well as the general health of these patients. Insulin delivery has been dominated by subcutaneous injections of both long acting insulin to cover the basal needs of the patient and by short acting insulin to compensate for meals and snacks. Recently, the development of electronic, external insulin infusion pumps has allowed the continuous infusion of fast acting insulin for the maintenance of the basal needs as well as the compensatory doses for meals and snacks. These infusion systems have shown to improve control of blood glucose levels, however, they suffer the drawbacks of size, cost, and complexity, which prevents many patients from accepting this technology over the standard subcutaneous injections. These pumps are electronically controlled and must be programmed to supply the desired amounts of basal and bolus insulin.
SUMMARYIn one embodiment of the invention, a disposable infusion device comprises a base arranged to adhere to a patient's skin, a cannula arranged to extend from the base to beneath the patient's skin to deliver a liquid medicament to the patient, and a source arranged to provide the cannula with a liquid medicament. The source includes a reservoir that holds the liquid medicament and a pressurizer that pressurizes the liquid medicament from within the reservoir to provide a flow of the liquid medicament to the cannula.
The reservoir may include a chamber that holds the liquid medicament and the pressurizer may include a moveable wall of the chamber that exerts a compressive force on the liquid medicament to pressurize the liquid medicament. The pressurizer further comprises a spring member, such as a coil spring, that urges the moveable wall against the liquid medicament.
The chamber may be a first chamber and the reservoir may further include a second chamber and a fixed wall separating the first chamber from the second chamber, the fixed wall including a flow restrictor that permit the liquid medicament to flow into the second chamber from the first chamber, and wherein the cannula is in fluid communication with the second chamber. The flow restrictor may be an orifice.
The source may be a first source, the liquid medicament may a first liquid medicament, and the device may further include a second source that provides the cannula with a second liquid medicament. The second source may comprise a pump that pumps the second liquid medicament to the cannula. The pump may be a fixed volume pump such as, for example, a fixed stroke piston pump. The second source may further comprise a reservoir that holds the second liquid medicament. The pressurizer may be a pressurized gas.
BRIEF DESCRIPTION OF THE DRAWINGSThe 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:
The port 10 further includes a cannula 15. The cannula 15 is carried by the funnel port 12. As known in the art, once the needle 14 and cannula 15 are positioned beneath the skin 18 as shown, the needle 14 is removed leaving the cannula 15 in a deployed position and ready to deliver insulin to the patient.
In the case when the system 30 includes multiple reservoirs, the system may have a mechanism for the selection of which insulin is infused at any given time. It also may provide control over how much of each particular insulin is determined to be delivered by having the patient depress the actuator 38 a desired number of times. For example, each activation might deliver 0.5 units of insulin. Therefore, if 3 units of insulin are desired, 6 depressions will deliver the desired amount.
The insulin in reservoir 52 is constantly delivered under the control of a mechanical timer pump 56. The timer pump is of the type known in the art to include a winder 58, a wind-up spring 60, and gears 62. The gears 62 drive a worn gear 63 and lead screw 65 to drive a piston 67. The piston 67 thus pressurizes the reservoir 52 to provide a constant flow of insulin to the cannula 66. When a bolus of fast acting insulin is required, such as at meals, the port 54 is used to inject the fast acting insulin into the reservoir 52. When the reservoir is full, further injected insulin will displace a like quantity of insulin from reservoir 52 thereby injecting the same into and out of the cannula 66.
Referring now to
More specifically, the device 120 includes a reservoir 122 for containing a fast acting insulin. The device further includes disk 124 having a groove 126 that increases in depth along the circumference of the disk 124. A flexible tube 130 extends from the reservoir 122 around the disk 124 and within the groove 126. A strap 132 extends from a fixed tie point 134 along the tube 130 to an actuator 136. As the disk is rotated in the clockwise direction, an increasing length of the tube 130 will reside in the groove 126. Conversely, counter-clockwise rotation of disk 124 will cause a decreased length of the tube 130 to reside in the groove 126. When the actuator 136 is moved in the direction of arrow 138, the strap 132 acts upon (compresses) the portion of the tube 130 not in the groove 126 to cause a measured bolus of insulin to be delivered to the infusion tube 140. Hence, as more tubing is acted upon by the strap 132, a larger volume bolus is delivered by peristaltic action. The disk 124 may be rotated by a dial, such as the dial 82 of the device 86 of
As may be noted, the pump includes a resilient membrane 174 sealed to a base 176 by a sealing ring 178. The base may be adhered to the patient's skin by adhesive tape (not shown). The pump 170 also includes an intake valve 180 which permits insulin to enter the inner cavity 184 formed by the membrane 174 and base 176 when the membrane returns to the configuration shown in
While particular embodiments of the present invention have been shown and described, modifications may be made, and 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.
Claims
1. A disposable infusion device comprising:
- a base arranged to adhere to a patient's skin;
- a cannula arranged to extend from the base to beneath the patient's skin to deliver a liquid medicament to the patient; and
- a source arranged to provide the cannula with a liquid medicament, the source including a reservoir that holds the liquid medicament and a pressurizer that pressurizes the liquid medicament from within the reservoir to provide a flow of the liquid medicament to the cannula.
2. The device of claim 1, wherein the reservoir includes a chamber that holds the liquid medicament and wherein the pressurizer includes a moveable wall of the chamber that exerts a compressive force on the liquid medicament to pressurize the liquid medicament.
3. The device of claim 2, wherein the pressurizer further comprises a spring member that urges the moveable wall against the liquid medicament.
4. The device of claim 3, wherein the spring member is a coil spring.
5. The device of claim 2, wherein the chamber is a first chamber and wherein the reservoir further includes a second chamber and a fixed wall separating the first chamber from the second chamber, the fixed wall including a flow restrictor that permit the liquid medicament to flow into the second chamber from the first chamber, and wherein the cannula is in fluid communication with the second chamber.
6. The device of claim 5, wherein the flow restrictor is an orifice.
7. The device of claim 1, wherein the source is a first source, wherein the liquid medicament is a first liquid medicament, and wherein the device further includes a second source that provides the cannula with a second liquid medicament.
8. The device of claim 7, wherein the second source comprises a pump that pumps the second liquid medicament to the cannula.
9. The device of claim 8, wherein the pump is a fixed volume pump.
10. The device of claim 8, wherein the pump is a piston pump.
11. The device of claim 8, wherein the pump is a fixed stroke piston pump.
12. The device of claim 11, wherein the second source further comprises a reservoir that holds the second liquid medicament.
13. The device of claim 1, wherein the pressurizer is a pressurized gas.
14. A disposable infusion device comprising:
- a base arranged to adhere to a patient's skin;
- a cannula arranged to extend from the base to beneath the patient's skin to deliver a liquid medicament to the patient; and
- a first source arranged to provide the cannula with a first liquid medicament, the first source including a reservoir that holds the first liquid medicament under pressure to provide a flow of the first liquid medicament to the cannula; and
- a second source arranged to provide a second liquid medicament to the cannula.
15. The device of claim 14, wherein the reservoir includes a moveable wall that exerts a compressive force on the liquid medicament to pressurize the liquid medicament.
16. The device of claim 15, further comprising a spring member that urges the moveable wall against the liquid medicament.
17. The device of claim 14, wherein the reservoir contains a pressurized gas to place the first liquid medicament under pressure.
18. The device of claim 14, wherein the second source comprises a pump that pumps the second liquid medicament to the cannula.
19. The device of claim 14, wherein the second source further comprises a second reservoir that holds the second liquid medicament.
20. The device of claim 19, wherein the second source further comprises a pump that pumps the second liquid medicament from the second reservoir to the cannula.
Type: Application
Filed: Feb 12, 2007
Publication Date: Dec 27, 2007
Applicant:
Inventors: Clifton Alferness (Port Orchard, WA), John Adams (Kirkland, WA), Daniel Hawkins (Newcastle, WA)
Application Number: 11/705,815
International Classification: A61M 5/155 (20060101);