External programmer for magnetically-adjustable cerebrospinal fluid shunt valve

• US 4,772,257 A
• Filed: 10/07/1986
• Issued: 09/20/1988
• Est. Priority Date: 12/08/1983
• Status: Expired due to Term

• Current Assignee: Carlos A. Hakim, Salomon Hakim
• Original Assignee: Carlos A. Hakim, Salomon Hakim
• Inventors: Hakim, Carlos A., Hakim, Salomon
• Primary Examiner(s): Jaworski, Francis
• Assistant Examiner(s): MANUEL, GEORGE C
• Application Number:
  US06/916,316
• Time in Patent Office: 714 Days
• Field of Search: 128/1 R, 128/748, 604/249, 604/153, 604/9, 251/129.11, 251/129.2, 335/138
• US Class Current: 604/9
• CPC Class Codes: A61F 2/0036 implantable A61F2/0018 takes precedence
• CPC Class Codes: A61M 27/006 Cerebrospinal drainage; Accessories therefor, e.g. valves
• CPC Class Codes: H02K 37/00 Motors with rotor rotating step by step and without interrupter or commutator driven by the rotor, e.g. stepping motors

Abstract

Adjusting the popping pressure of a surgically-implanted shunt valve of the type having one or more elements adapted to move under the influence of a magnetic field, by positioning an adjustment device in proximity to the implanted valve but external to the body, providing the adjustment device with a plurality of electromagnets, selectively energizing the electromagnets through a sequence of steps in which different ones of the electromagnets are energized at successive steps, selecting the sequence of energization and the orientation and strength of the electromagnets so that the elements in the implanted device are caused to move in response to the sequence of energization to thereby adjust the popping pressure.

Claims

1. 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.

2. 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.

3. 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.

4. 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.

5. 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.

6. 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.

7. 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.

8. 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.

9. 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.

10. 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.

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

11. 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.

12. 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.

13. 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.

14. 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.

15. 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.

16. 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.

17. 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.

18. 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.

19. 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.

20. 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.