Implantable drug infusion device having a flow regulator

• US 6,878,135 B1
• Filed: 11/15/2000
• Issued: 04/12/2005
• Est. Priority Date: 02/02/1998
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Renaud, Philippe, Amacker, Christian, Haller, Markus
• Primary Examiner(s): Thanh, LoAn H.
• Application Number:
  US09/712,237
• Time in Patent Office: 1,609 Days
• Field of Search: 604/93.01, 604/131, 604/133, 604/141, 604/175, 6048901-8911, 604/132, 604/145, 604 65- 67, 604236-238, 604/246, 604/247, 604/256, 604151-152, 604/154, 422/68.1, 204/280, 600/347, 600/372, 600/373
• US Class Current: 604/246
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/16813 by controlling the degree of opening of the flow line
• CPC Class Codes: G05D 7/0113 the sensing element acting as a valve

Abstract

An implantable drug infusion device which features an improved flow regulator which permits the flow rate to be independent of reservoir pressure within a given pressure range. The flow regulator features a membrane having a hole, the membrane itself positioned above a bottom layer such that sufficient deflection of the membrane causes the membrane to engage against the bottom layer. As liquid flows through the hole a drag force is applied to the edge of the hole resulting in a deflection of the membrane. Once contact is made between the membrane and the bottom layer, then flow reduced. In a further embodiment the bottom layer features a variable flow channel such that upon membrane deflection flow may only proceed through the hole and through the flow channel. By tailoring the shape and length of the variable flow channel the flow characteristics of the regulator versus pressure may be adjusted. In a further embodiment the flow regulator also features a flow sensor integrated therewith. This integrated sensor provides a measurement of flow and may be coupled to the flow regulator to provide feedback thereto.

Claims

1. A flow regulator, comprising:

a membrane having at least one hole;

a bottom layer comprising an outlet; and

a fluid pathway;

the membrane being positioned above the bottom layer, the fluid pathway being defined from above the membrane through the hole and along the bottom layer on the side facing the membrane and through the outlet, wherein flow through the hole causes the membrane to deflect and engage against at least on portion of the bottom layer thereby impeding the fluid pathway by impeding flow through the hole in the membrane while not impeding flow through the outlet.

2. A flow regulator according to claim 1, wherein the side of the bottom layer facing the membrane further compromises at least one channel which constitutes a part of the fluid pathway, the first end of the channel being in connection with an outlet port, wherein flow through the hole causes the membrane to deflect and engage against at least one portion of the bottom layer thereby forcing the fluid in this portion to flow only in the channel.

3. A flow regulator according to claim 2, wherein the shape and length of the channel are so designed that an increase of pressure generates an increase of the contact area between the membrane and the bottom layer, thereby defining an additional segment to the channel where fluid is confined, said configuration allowing a proper adjustment of the flow versus pressure characteristics.

4. A flow regulator according to claim 3, wherein the section of the channel is constant.

5. A flow regulator according to claim 3, wherein the shape and length of the channel are so designed that the fluid resistance is proportional to the pressure, implying thereby a flow rate independent of the pressure.

6. A flow regulator according to claim 4 or 5, wherein the channel is spiral shaped groove.

7. A flow regulator according to any of claims 1 to 5, wherein the membrane further includes means for sensing the deflection of the membrane.

8. A flow regulator according to any of claims 1 to 5, wherein the fluid pathway is obstructed when the membrane has reached a predetermined degree of deflection.

9. A flow regulator, compromising:

a membrane having at least one hole;

a bottom layer; and

a fluid pathway;

the membrane being positioned above the bottom layer, the fluid pathway being defined from above the membrane through the hole and along the bottom layer on the side facing the membrane, wherein flow thorough the hole causes the membrane to deflect and engage against at least one portion of the bottom layer there by impending the fluid pathway,

wherein the side of the bottom layer facing the membrane further compromises at least one channel which constitutes a part of the fluid pathway, the first end of the channel being in connection with an outlet port, wherein flow through the hole causes the membrane to deflect and engage against at least one portion of the bottom layer thereby forcing the fluid in this portion to flow only in the channel,

wherein the shape and length of the channel are so designed that an increase of pressure generates an increase of the contact area between the membrane and the bottom layer, thereby defining an additional segment of the channel where fluid is confined, said configuration allowing a proper adjustment of the flow versus pressure characteristics,

wherein a section of the channel is constant and the channel is spiral shaped groove.

10. A flow regulator, compromising:

a membrane having at least one hole;

a bottom layer; and

a fluid pathway;

the membrane being positioned above the bottom layer, the fluid pathway being defined from above the membrane through the hole and along the bottom layer on the side facing the membrane, wherein flow thorough the hole causes the membrane to deflect and engage against at least one portion of the bottom layer there by impending the fluid pathway,

wherein the side of the bottom layer facing the membrane further compromises at least one channel which constitutes a part of the fluid pathway, the first end of the channel being in connection with in outlet port, wherein flow through the hole causes the membrane to deflect and engage against at least one portion of the bottom layer thereby forcing the fluid in this portion to flow only in the channel,

wherein the shape and length of the channel are so designed that an increase generates an increase of the contact area between the membrane and the bottom layer, thereby defining an additional segment to the channel where fluid is confined, said configuration allowing a proper adjustment of the flow versus pressure characteristics,

wherein the shape and length of the channel are so designed that the fluid resistance is proportional to the pressure, implying thereby a flow rate independent of the pressure and the channel is a spiral shaped groove.