Implantable drug infusion device having a flow regulator

• US 6,203,523 B1
• Filed: 02/02/1998
• Issued: 03/20/2001
• Est. Priority Date: 02/02/1998
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Renaud, Philippe, Haller, Markus, Amacker, Christian
• Primary Examiner(s): Weiss, John G.
• Assistant Examiner(s): Thanh, LoAn H.
• Application Number:
  US09/017,194
• Time in Patent Office: 1,142 Days
• Field of Search: 604/65-67, 604/93, 604/236-238, 604/246-247, 604/256, 604/131, 604/151-152, 604/154, 604/890.1, 604/891.1, 604/892.1, 604/93.01
• US Class Current: 604/93.01
• 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. An implantable drug infusion device, comprising:

an hermetic enclosure;

a fluid reservoir positioned within the hermetic enclosure, the fluid reservoir having means for maintaining a fluid therein between a first pressure and a second pressure;

means for delivering the fluid into a patient'"'"'s body;

a substrate having a first fluid outlet port disposed therein, the first fluid outlet port being operably connected to the means for delivering a fluid into the patient'"'"'s body;

a flow regulator comprising a deflectable membrane having a fluid lumen disposed therein, the flow regulator being coupled to the fluid reservoir, and

a fluid pathway contiguous with the first fluid outlet port and the lumen, at least portions of the fluid pathway being disposed between the first fluid outlet port and the lumen;

wherein at least portions of the deflectable membrane, in response to the pressure of the fluid in the reservoir being between the first pressure and the second pressure, deflect insufficiently to terminate a flow of the fluid from the reservoir through the lumen and thence the first fluid outlet port via the fluid pathway.

2. An implantable drug infusion device according to claim 1, wherein the means for sensing the rate of fluid flow through the flow regulator comprises at least one piezo-resistive element operably connected to the deflectable membrane.

3. An inplantable drug infusion device according to claim 2, further comprising means for determining the amount of deflection of the membrane.

4. An implantable drag infusion device according to claim 1, further comprising means for calibrating the amount of deflection of the membrane in respect of a predetermined pressure of the fluid in the reservoir.