Implantable manually actuated medication dispensing system

Claim 2

A dispensing system for dispensing a metered volume of fluid from a reservoir to a dispensing port, comprising: a housing; a reservoir; means within said housing defining a fluid circuit serially including a first check valve, a safety pump, a second check valve, a metering pump, and a third check valve; said safety pump being operable in response to the application of a first force applied externally to said housing for advancing fluid through said second check valve to said metering pump; and said metering pump being operable in response to the application of a second force applied externally to said housing for advancing a predetermined volume of said fluid advanced from said safety pump through said third check valve to said dispensing port.

Claim 3

A dispensing system as defined in claim 1 wherein said metering pump includes bias means for restoring said pump to a fluid receiving condition, and wherein said biasing means exert a force on fluid in said metering pump less than that exerted thereon by said second check valve.

Claim 4

A dispensing system as defined in claim 1 wherein said first check valve closes at a lower pressure than said second and third check valves, said safety pump includes bias means for restoring said pump to a fluid receiving condition and said restoring force exceeds the closing force of said first check valve.

Claim 5

A dispensing system as defined in claim 1 wherein the reservoir is at least partially defined by said housing and includes a flexible and expandable fluid impermeable membrane.

Claim 6

A dispensing system as defined in claim 1 wherein said metering pump comprises a plunger-type pump including an actuator actuable from the exterior of said housing.

Claim 7

A dispensing system as defined in claim 5 wherein said safety pump comprises a plunger-type pump including an actuator stem actuable from the exterior of said housing.

Claim 8

An implantable manually-actuated dispensing system for dispensing a metered volume of fluid from a reservoir through a dispensing port, comprising: an implantable housing defining a fluid circuit extending between the fluid reservoir and the dispensing port; safety pump means within said housing operable in response to a first applied force; metering pump means within said housing operable in response to a second applied force; said fluid circuit serially including said safety pump means and said metering pump means; said safety pump means being operable in response to the application of said first applied force for advancing said fluid along said fluid circuit to said metering pump, and preventing the flow of fluid from the fluid reservoir to said metering pump in the absence of said application of said applied force; and said metering pump means being operable in response to the application of a second applied force for advancing a predetermined volume of said fluid advanced from said first pump along said fluid circuit to the dispensing port.

Claim 9

An implantable manually-actuated dispensing system for dispensing a metered volume of fluid from a reservoir through a dispensing port, comprising: an implantable housing defining a fluid circuit extending between the fluid reservoir and the dispensing port; safety pump means within said housing operable in response to a first applied force; metering pump means within said housing operable in response to a second applied force; said fluid circuit serially including said safety pump means and said metering pump means; said safety pump means being operable in response to the application of said first applied force for advancing said fluid along said fluid circuit to said metering pump, and preventing the flow of fluid from the fluid reservoir to said metering pump in the absence of said application of said applied force; and said metering pump means being operable in response to the application of a second applied force for advancing a predetermined volume of said fluid advanced from said first pump along said fluid circuit to the dispensing port.

Claim 10

A dispensing system as defined in claim 7 wherein said housing further defines the fluid reservoir.

Claim 11

A dispensing system as defined in claim 8 wherein said fluid circuit includes a check valve between said reservoir and said safety pump means.

Claim 12

A dispensing system as defined in claim 7 wherein said fluid circuit includes a check valve between said safety pump means and said metering pump means.

Claim 13

A dispensing system as defined in claim 10 wherein said fluid circuit includes an additional check valve between the reservoir and said safety pump means.

Claim 14

A dispensing system as defined in claim 7 wherein said safety valve means are biased closed by fluid pressure in the fluid reservoir.

Claim 15

An implantable dispensing system for dispensing a predetermined dosage of fluid from a reservoir to a dispensing site, comprising: a housing defining first and second pump chambers and a fluid circuit serially interconnecting the reservoir, said chambers and the dispensing site; safety pump means including a first plunger disposed in said first pump chamber, said plunger being actuable by application of a first externally applied force to advance a predetermined volume of fluid from said first pump chamber through said fluid circuit to said second chamber; and metering pump means including a plunger disposed in said second pump chamber, said plunger being responsive to application of a second externally applied force for urging a predetermined dosage of fluid from said volume advanced by said safety pump means from said second chamber through said fluid circuit to the dispensing site.

Claim 16

An implantable dispensing system for dispensing a predetermined dosage of fluid from a reservoir to a dispensing site, comprising: a housing defining first and second pump chambers and a fluid circuit serially interconnecting the reservoir, said chambers and the dispensing site; safety pump means including a first plunger disposed in said first pump chamber, said plunger being actuable by application of a first externally applied force to advance a predetermined volume of fluid from said first pump chamber through said fluid circuit to said second chamber; and metering pump means including a plunger disposed in said second pump chamber, said plunger being responsive to application of a second externally applied force for urging a predetermined dosage of fluid from said volume advanced by said safety pump means from said second chamber through said fluid circuit to the dispensing site.

Claim 17

An implantable dispensing system as defined in claim 13 wherein said fluid circuit includes a check valve between said safety pump and said metering pump.

Claim 18

A dispensing system as defined in claim 14 wherein said metering pump means include biasing means for restoring said plunger to fluid receiving position and said biasing means exert a force on said fluid less than that exerted thereon by said check valve.

Claim 19

A dispensing system as defined in claim 14 wherein said fluid circuit includes an additional check valve between the reservoir and said first pump chamber.

Claim 20

An implantable dispensing system as defined in claim 13 further including: a dispensing port; a first passageway between the reservoir and said first pump chamber, said passageway including a first check valve; a second passageway between said first pump chamber and said second pump chamber, said second passageway including a second check valve; and a third passageway between said second pump chamber and said dispensing port.