Infusion pump system and method
Some embodiments of an infusion pump system include a pump device with a drive system that is configured to attach with a medicine cartridge in manner that reduces the likelihood of dosage inaccuracies. In one example, the drive system of the pump device can be equipped with a plunger engagement device that is configured to mechanically anchor into a plunger of the medicine cartridge, and then to bias the plunger of the medicine cartridge in a direction toward a piston rod of the drive system.
1. A method of operating an infusion pump device, comprising:
receiving a medicine cartridge in an internal space of a housing of a pump device, wherein a plunger engagement device is positioned in the internal space;
penetrating a plunger of the medicine cartridge with at least one penetration member of the plunger engagement device;
after penetrating the plunger with said at least one penetration member, applying a spring bias to the plunger to bias the plunger in a first direction towards a component of a drive system of the pump device; and
operating the drive system of the pump device to advance the plunger in a second direction, the second direction being opposite the first direction.
2. The method of claim 1 , wherein the steps of penetrating the plunger and applying the spring bias to the plunger comprise applying a longitudinal force to the medicine cartridge.
3. The method of claim 2 , wherein applying the spring bias to the plunger further comprises adjusting a spring from a deactivated condition to an activated condition by applying the longitudinal force.
4. The method of claim 2 , wherein the step of applying the longitudinal force comprises engaging a cap device with the pump housing to retain the medicine cartridge in the internal space.
5. The method of claim 1 , wherein the pump device comprises the drive system positioned within the housing, the drive system comprising a piston rod configured to forwardly advance toward the medicine cartridge when the medicine cartridge is received in the internal space, the plunger engagement device being coupled to the piston rod.
6. The method of claim 5 , further comprising forwardly advancing the piston rod to deliver medication from the medicine cartridge after applying the spring bias to the plunger.
7. The method of claim 5 , wherein the plunger engagement device comprises a spring adjustable from a deactivated condition to an activated condition and wherein the plunger engagement device is disposed at an end of the piston rod located proximate to the plunger when the spring is in the activated condition.
8. The method of claim 7 , wherein the spring is in the deactivated condition when the at least one penetration member penetrates the plunger of the medicine cartridge.
9. The method of claim 8 , wherein the spring bias is applied to the plunger by switching the spring to the activated condition.
10. The method of claim 7 , wherein the plunger engagement device further comprises a retention plate comprising a chassis seated against the spring causing the retention plate to move as the spring expands during adjustment from the deactivated condition to the activated condition, and wherein the chassis is fixedly coupled to the at least one penetration member.
11. The method of claim 7 , wherein the plunger engagement device further comprises a trigger tab engageable with a portion of the medicine cartridge to adjust the spring from the deactivated condition to the activated condition in response to a longitudinal force applied to the medicine cartridge.
12. The method of claim 11 , wherein the trigger tab extends from a chassis supporting the at least one penetration member, and wherein the trigger tab comprises an oblique inwardly facing lip bearing against the portion of the medicine cartridge to move the chassis across the medicine cartridge in response to the longitudinal force.
13. The method of claim 5 , wherein the plunger engagement device comprises a spring adjustable from a deactivated condition to an activated condition, wherein the plunger engagement device further comprises a piston hub fixedly coupled to the piston rod, the piston hub comprising a base supporting the spring and a pusher block contacting the plunger when the spring is in the activated condition.
14. The method of claim 1 , further comprising securing a cap device to the pump housing to retain the medicine cartridge therein.
15. The method of claim 14 , wherein the step of securing the cap device to the pump housing acts upon the medicine cartridge to provide a longitudinal force, which causes the penetrating of the plunger and the applying of the spring bias to the plunger.
16. The method of claim 14 , wherein the cap device is configured to engage the pump housing, wherein the cap device comprises a needle device that penetrates an output portion of the medicine cartridge when the cap device engages the pump housing.
17. The method of claim 1 , wherein the plunger engagement device further comprises a spring hub comprising a plurality of radial tabs obliquely outward along a curved upslope to meet an inner wall of the medicine cartridge when the medicine cartridge is received by the pump housing.
18. The method of claim 1 , wherein the at least one penetration member comprises a pointed head and opposing retention barbs.
19. The method of claim 1 , wherein the plunger engagement device further comprises a catch member engageable with a portion of a piston hub supporting a spring, and wherein the catch member is releasable from the portion of the piston hub to adjust the spring from a deactivated condition to an activated condition.
20. The method of claim 1 , wherein the pump device further comprises a controller device removably attachable to the housing, wherein the controller device houses control circuitry configured to communicate with the drive system positioned in the housing to control dispensation of medicine from the pump device.