Metal bellows position feedback for hydraulic control of an adjustable gastric band
AssigneeEthicon Endo-Surgery, Inc.
InventorsWilliam L. Hassler, Jr., Daniel F. Dlugos, Jr., Rocco Crivelli
Life of this patent
Estimating the term…
Abstract
A remotely controlled gastric band system that is practically immune to external magnetic fields, such as from a Magnetic Resonance Imaging (MRI) machine, incorporates a bi-directional pump and fluid reservoir to adjust fluid volume for hydraulic control of a gastric band. A piezoelectric driver (e.g., rotary actuator, linear actuator) selectively compresses and expands a metal bellows hermetically sealed within a biocompatible and nonferromagnetic enclosure or case such as titanium. Directly sensing a position of the metal bellows yields an accurate reading of volume contained therein, allowing for closed-loop control of the gastric band.
Claims12
A method for remotely hydraulically controlling a hydraulically actuated therapeutic member, the method comprising:
- providing a hydraulically actuated therapeutic device;
- providing an implantable infuser device, the implantable infuser device comprising:
- an accumulator in fluid communication with the hydraulically actuated therapeutic device and having a surface movable to vary a contained volume between a first volume and a second volume,
- an induction position sensor inductively coupled to the movable surface of the accumulator and operably configured to sense an absolute position value,
- a closed loop controller responsive to a target volume value and the absolute position value to position the movable surface of the accumulator to the target volume value, and
- an enclosure encompassing the accumulator, wherein the position sensor comprises an inductive position sensor including an inductive target coupled for movement with the movable surface of the accumulator and an inductive coil attached to an internal surface of the enclosure proximate to the inductive target;
- transmitting a command to the infuser device to cause a change of volume of the accumulator of the infuser device to shift fluid between the infuser device and the hydraulically actuated therapeutic device;
- sensing accumulator position;
- calculating an error signal based upon a commanded volume and a current volume related to the sensed accumulator position;
- and
- commanding an actuator to change accumulator position based upon the calculated error signal.
An implantable infuser device for hydraulically actuating an implanted therapeutic device, the implantable infuser device comprising:
- an accumulator having a surface that is movable between a first and second position to selectively vary a contained fluid volume;
- a position sensor coupled to the movable surface of the accumulator and operably configured to sense an absolute position value;
- a closed loop controller responsive to a target volume value and the absolute position value to position the movable surface of the accumulator to the target volume value:
- and
- an enclosure encompassing the accumulator, wherein the position sensor comprises an inductive position sensor including an inductive target coupled for movement with the movable surface of the accumulator and an inductive coil attached to an internal surface of the enclosure proximate to the inductive target.
An apparatus, comprising:
- a hydraulically actuated therapeutic device comprising a fluid bladder;
- and an implantable infuser device comprising:
- an accumulator in fluid communication with the fluid bladder and having a surface movable to vary a contained volume between a first volume and a second volume,
- an inductive position sensor coupled to the movable surface of the accumulator and operably configured to sense an absolute position value, wherein the inductive position sensor further comprises computation circuitry operably configured to relate a sensed value from the inductive position sensor to the absolute position value, and
- a closed loop controller responsive to a target volume value and the absolute position value to position the movable surface of the accumulator to the target volume value.
Dependencies are inferred from the claim text.