Programmable implantable infusate pump
First Claim
1. A programmable implantable infusate pump comprisingA. a housing;
- B. a variable volume infusate chamber in the housing;
C. means for conducting infusate from said chamber to an infusion site outside the housing;
D. a variable volume fluid pressure reservoir in the housing;
E. a variable volume fluid displacement reservoir in the housing;
F. a fluid path extending between the pressure reservoir and the displacement reservoir, said path defining a flow restriction, said reservoirs and said path arranged to be filled with a substantially incompressible control fluid;
G. means for monitoring the fluid pressure differential across said restriction and producing indications in response thereto;
H. means acting between a reference position and the pressure reservoir for applying a substantially constant force to the pressure reservoir tending to reduce its volume; and
I. means responsive to said indications for intermittently shifting the reference position so as to maintain a selected infusate flow rate from said chamber.
8 Assignments
0 Petitions
Accused Products
Abstract
A programmable implantable infusion pump includes a housing containing a variable volume infusate chamber and variable volume control fluid pressure and displacement reservoirs. A conduit conducts infusate from the chamber exteriorly of the housing. A restricted fluid path exists between the two reservoirs which are filled with an incompressible control fluid. A loaded spring applies a constant force to the pressure reservoir causing fluid flow between the two reservoirs. The differential pressure across the flow restriction is sampled by a microprocessor which computes the fluid flow rate, that rate being proportional to the infusate flow rate from the chamber. When the fluid flow rate deviates from a programmed value, the processor issues an error command to a battery-driven motor which reloads the spring to reestablish the constant force on the pressure reservoir. The infusate flow rate may be changed automatically during the day in accordance with a programmed schedule and that schedule may be changed by reprogramming the processor using a telemetry receiver contained in the housing.
774 Citations
28 Claims
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1. A programmable implantable infusate pump comprising
A. a housing; -
B. a variable volume infusate chamber in the housing; C. means for conducting infusate from said chamber to an infusion site outside the housing; D. a variable volume fluid pressure reservoir in the housing; E. a variable volume fluid displacement reservoir in the housing; F. a fluid path extending between the pressure reservoir and the displacement reservoir, said path defining a flow restriction, said reservoirs and said path arranged to be filled with a substantially incompressible control fluid; G. means for monitoring the fluid pressure differential across said restriction and producing indications in response thereto; H. means acting between a reference position and the pressure reservoir for applying a substantially constant force to the pressure reservoir tending to reduce its volume; and I. means responsive to said indications for intermittently shifting the reference position so as to maintain a selected infusate flow rate from said chamber. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification