US4772257A — External programmer for magnetically-adjustable c…

Claim 1

Independent Claim 122 words

The method of adjusting the working pressure of a surgically-implanted valve of the type having at least one element adapted to move under the influence of a magnetic field, said method comprising the steps of: positioning an adjustment device in proximity to said implanted valve but external to the body, said adjustment device including a plurality of electromagnets; selectively energizing said electromagnets through a sequence of steps in which different ones of said electromagnets are energized at successive steps; and selecting said sequence of energization and selecting the orientation and strength of said electromagnets so that said at least one element in said implanted device are caused to move in response to said sequence of energization to thereby adjust said working pressure.

Claim 2

Independent Claim 122 words

The method of adjusting the working pressure of a surgically-implanted valve of the type having at least one element adapted to move under the influence of a magnetic field, said method comprising the steps of: positioning an adjustment device in proximity to said implanted valve but external to the body, said adjustment device including a plurality of electromagnets; selectively energizing said electromagnets through a sequence of steps in which different ones of said electromagnets are energized at successive steps; and selecting said sequence of energization and selecting the orientation and strength of said electromagnets so that said at least one element in said implanted device are caused to move in response to said sequence of energization to thereby adjust said working pressure.

Claim 3

Dependent Claim 34 words

The method of claim 1 wherein said step of selectively energizing said electromagnets through a sequence includes changing the polarity (north or south) of said electromagnets from one step in the sequence to another.

Claim 4

Dependent Claim 32 words

The method of claim 2 wherein at least one of said electromagnets has the reverse polarity of at least one other of said electromagnets during at least one step of said sequence.

Claim 5

Dependent Claim 57 words

The method of claim 3 wherein the elements of said implanted device are positioned around a first axis in said implanted valve, wherein said electromagnets are positioned around a second axis in said adjustment device, and wherein said adjustment device is positioned with respect to said valve so that said first and second axes are approximately coaxial.

Claim 6

Dependent Claim 31 words

The method of claim 4 wherein there are four said electromagnets spaced 90° apart around said axis and wherein said sequence consists of that shown in the table of FIG. 11.

Claim 7

Dependent Claim 77 words

The method of claim 4 wherein said sequence is selected to cause the field vector of the magnetic field generated by said electromagnets to rotate about said second axis through an incremental angular movement at each step in said sequence, and said sequence and the strength and orientation of said electromagnets are selected so that said elements are caused to rotate about said first axis in the same direction (clockwise or counterclockwise) as said magnetic field rotation.

Claim 8

Dependent Claim 49 words

The method of claim 1 wherein said electromagnets are energized to deliver a pulsed magnetic field, with each pulse corresponding to one step in said sequence, and wherein said at least one element of said implanted device goes through an incremental movement for each pulse in said magnetic field.

Claim 9

Dependent Claim 28 words

The method of claim 1 wherein input keys for specifying working pressure are provided, and keys corresponding to a desired working pressure are depressed to initiate said sequence.

Claim 10

Dependent Claim 27 words

The method of claim 1 wherein each step in said sequence causes an incremental movement of said elements and a corresponding incremental change in said working pressure.

Claim 11

Dependent Claim 55 words

The method of claim 9 wherein said sequence comprises a first sequence long enough to move said elements to a known reference position (e.g., the lowest pressure setting) from any possible starting position and a second sequence of length selected to move said elements through the number of increments corresponding to the desired working pressure.

Claim 12

Dependent Claim 118 words

Apparatus for externally programming a surgically-implanted valve to adjust its working pressure, said surgically-implanted valve being of the type having at least one element adapted to move under the influence of a magnetic field, said apparatus comprising: a housing; a plurality of electromagnets supported by said housing; and means electrically connected to said electromagnets for selectively energizing said electromagnets through a sequence of steps in which difference ones of said electromagnets are energized at successive steps, the sequence of energization and the orientation and strength of said electromagnets being selected so that said at least one element in said implanted device are caused to move in response to said sequence of energization to thereby adjust said working pressure.

Claim 13

Dependent Claim 118 words

Apparatus for externally programming a surgically-implanted valve to adjust its working pressure, said surgically-implanted valve being of the type having at least one element adapted to move under the influence of a magnetic field, said apparatus comprising: a housing; a plurality of electromagnets supported by said housing; and means electrically connected to said electromagnets for selectively energizing said electromagnets through a sequence of steps in which difference ones of said electromagnets are energized at successive steps, the sequence of energization and the orientation and strength of said electromagnets being selected so that said at least one element in said implanted device are caused to move in response to said sequence of energization to thereby adjust said working pressure.

Claim 14

Dependent Claim 26 words

The apparatus of claim 11 wherein said sequence includes changing the polarity (north or south) of said electromagnets from one step in the sequence to another.

Claim 15

Dependent Claim 32 words

The apparatus of claim 12 wherein at least one of said electromagnets has the reverse polarity of at least one other of said electromagnets during at least one step of said sequence.

Claim 16

Dependent Claim 55 words

The apparatus of claim 13 wherein the elements of said implanted device are positioned around a first axis in said implanted valve, wherein said electromagnets are positioned around a second axis in said adjustment device, and wherein said housing is shaped to facilitate orienting it so that said first and second axes are approximately coaxial.

Claim 17

Dependent Claim 31 words

The apparatus of claim 14 wherein there are four said electromagnets spaced 90° apart around said axis and wherein said sequence consists of that shown in the table of FIG. 11.

Claim 18

Dependent Claim 77 words

The apparatus of claim 14 wherein said sequence is selected to cause the field vector of the magnetic field generated by said electromagnets to rotate about said second axis through an incremental angular movement at each step in said sequence, and said sequence and the strength and orientation of said electromagnets are selected so that said elements are caused to rotate about said first axis in the same direction (clockwise or counterclockwise) as said magnetic field rotation.

Claim 19

Dependent Claim 53 words

The apparatus of claim 11 wherein said means for energizing said electromagnets includes means to generate a pulsed magnetic field, with each pulse corresponding to one step in said sequence, and wherein said at least one element of said implanted device goes through an incremental movement for each pulse in said magnetic field.

Claim 20

Dependent Claim 28 words

The apparatus of claim 11 further comprising input keys for specifying working pressure and means for translating activation of said input keys to electrical signals controlling said electromagnets.

Claim 21

Dependent Claim 30 words

The apparatus of claim 11 wherein each step in said sequence causes an incremental movement of said at least one element and a corresponding incremental change in said working pressure.

Claim 22

Dependent Claim 58 words

The method of claim 19 wherein said sequenoe comprises a first sequence long enough to move said elements to a known reference position (e.g., the lowest pressure setting) from any possible starting position and a second sequence of length selected to move said at least one element through the number of increments corresponding to the desired working pressure.

Claim 23

Dependent Claim 24 words

The method of claim 1 wherein said valve is a shunt valve and said working pressure is the popping pressure of said shunt valve.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1991-09-20	1992-03-21	1992-09-20	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1995-09-20	1996-03-21	1996-09-20	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1999-09-20	2000-03-21	2000-09-20	$7700.00	Window Closed / Lapsed

External programmer for magnetically-adjustable cerebrospinal fluid shunt valve

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag