Dual drug delivery device
View Patent ↗A liquid delivery apparatus for the intrathecal delivery of one or more medications to a patient is disclosed. The liquid delivery apparatus generally includes a liquid reservoir, a liquid metering unit fluidly connected to the liquid reservoir, and a catheter delivery tube fluidly connected to the liquid metering unit. Preferably, the liquid delivery apparatus includes two or more liquid reservoirs. In various embodiments, the liquid reservoir includes a deformable balloon and a compressive sleeve spring as a pressure source, the liquid metering unit is a piezoelectrically actuated microvalve, and/or diagnostic sensors are included in the apparatus. The disclosed apparatus are compact, volume-efficient, energy-efficient, capable of delivering accurate fluid volumes, and address problems associated with multi-medication therapies. Methods of operating the liquid delivery apparatus are also disclosed.
1. A liquid delivery apparatus comprising a liquid delivery pathway, the liquid delivery pathway comprising:
a liquid reservoir comprising a deformable balloon and a pressure source selected from the group consisting of a compressive sleeve spring and an electrolytic fluid cell;
a liquid metering unit comprising a throttle, the liquid metering unit fluidly connected to the liquid reservoir;
a pressure sensor fluidly connected to the liquid reservoir between the liquid reservoir and the liquid metering unit throttle; and,
a catheter delivery tube fluidly connected to the liquid metering unit.
2. The liquid delivery apparatus of claim 1 , wherein the liquid reservoir further comprises a refill port.
3. The liquid delivery apparatus of claim 1 further comprising a bolus port fluidly connected to the catheter delivery tube.
4. The liquid delivery apparatus of claim 1 , wherein the pressure source is an electrolytic fluid cell.
5. The liquid delivery apparatus of claim 1 further comprising a liquid delivery control module, the liquid delivery control module comprising:
a microprocessor electrically connected to the throttle and the means for measuring the volume of the liquid reservoir; and,
a battery electrically connected to the microprocessor.
6. The liquid delivery apparatus of claim 5 , comprising a plurality of liquid delivery pathways, wherein the microprocessor is capable of independently controlling liquid flow through each liquid delivery pathway.
7. The liquid delivery apparatus of claim 1 further comprising a plurality of liquid delivery pathways.
8. The liquid delivery apparatus of claim 7 , comprising a liquid delivery catheter fluidly connected to the catheter delivery tube of each of the plurality of liquid delivery pathways.
9. The liquid delivery apparatus of claim 1 , wherein the pressure source is a compressive sleeve spring comprising a piezoresistive material.
10. The liquid delivery apparatus of claim 9 , wherein the compressive sleeve spring comprises a Co/Cr/Ni alloy.
11. The liquid delivery apparatus of claim 1 , wherein the throttle comprises a piezoelectrically actuated microvalve.
12. The liquid delivery apparatus of claim 11 , wherein the piezoelectrically actuated microvalve comprises:
a first plate and a second plate spaced apart and joined together to define a flow path having an inlet fluidly connected to the liquid reservoir and an outlet fluidly connected to the catheter delivery tube; and,
a piezoelectric material external to the flow path and in contact with the first plate.
13. The liquid delivery apparatus of claim 12 , wherein:
the first plate comprises a silicon-on-insulator substrate;
the second plate comprises glass; and,
the piezoelectric material comprises lead zirconium titanate.
14. A liquid delivery apparatus comprising:
a liquid reservoir comprising a deformable balloon having an interior volume and at least one deformable interior wall in the interior volume, the at least one deformable interior wall defining a plurality of reservoir chambers in the interior volume;
a plurality of liquid metering units, each of which is fluidly connected to one of the reservoir chambers;
a at least one pressure sensor fluidly connected to at least one of the reservoir chambers between the reservoir chamber and the corresponding liquid metering unit; and,
a plurality of catheter delivery tubes, each of which is fluidly connected to one of the liquid metering units.
15. The liquid delivery apparatus of claim 14 further comprising a liquid delivery catheter connected to each of the catheter delivery tubes.
16. The liquid delivery apparatus of claim 14 , wherein the liquid reservoir further comprises a refill port.
17. The liquid delivery apparatus of claim 14 further comprising a plurality of bolus ports, each of which is fluidly connected to one of the catheter delivery tubes.
18. The liquid delivery apparatus of claim 14 , wherein
the liquid reservoir further comprises a pressure source selected from the group consisting of a compressive sleeve spring, a torsion spring, and an electrolytic fluid cell; and
each liquid metering unit comprises a throttle.
19. The liquid delivery apparatus of claim 18 , wherein the pressure source is a torsion spring.
20. The liquid delivery apparatus of claim 18 , wherein the pressure source is an electrolytic fluid cell.
21. The liquid delivery apparatus of claim 18 , further comprising a liquid delivery control module, the liquid delivery control module comprising:
a microprocessor electrically connected to the throttle and the means for measuring the volume of the liquid in the reservoir chambers; and
a battery electrically connected to the microprocessor.
22. The liquid delivery apparatus of claim 21 , wherein the microprocessor is capable of independently controlling liquid flow through each throttle.
23. The liquid delivery apparatus of claim 18 , wherein the pressure source is a compressive sleeve spring.
24. The liquid delivery apparatus of claim 23 , wherein the compressive sleeve spring comprises a Co/Cr/Ni alloy.
25. The liquid delivery apparatus of claim 18 , wherein the throttle comprises a piezoelectrically actuated microvalve.
26. The liquid delivery apparatus of claim 25 , wherein the piezoelectrically actuated microvalve comprises:
a first plate and a second plate spaced apart and joined together to define a flow path having an inlet fluidly connected to the liquid reservoir and an outlet fluidly connected to the plurality of the catheter delivery tubes; and,
a piezoelectric material external to the flow path and in contact with the first plate.
27. The liquid delivery apparatus of claim 26 , wherein:
the first plate comprises a silicon-on-insulator substrate;
the second plate comprises glass; and,
the piezoelectric material comprises lead zirconium titanate.
28. A method of delivering a plurality of medications to a patient in need thereof, the method comprising:
providing the liquid delivery apparatus of claim 7 , the apparatus further comprising a microprocessor electrically connected to the throttle and the pressure sensor;
charging the liquid delivery apparatus with the plurality of medications, wherein at least one liquid reservoir contains a medication that is different from the medication contained in another liquid reservoir; and,
delivering the plurality of medications to the patient at independently controlled flow rates by independently actuating the throttle of each liquid delivery pathway in response to a flow control program stored in the microprocessor.