IMPLANTABLE MICRO-SYSTEM FOR TREATMENT OF HYDROCEPHALUS

Abstract

An implantable system for the treatment of hydrocephalus includes a plurality of microneedles in a fixed array relative to each other adapted to extend from the subarachnoid space containing CSF surrounding the brain, through dura mater forming the wall of the superior sagital sinus. A microvalve is associated with a proximal end of each of the microneedles and is adapted to permit the flow of cerebrospinal fluid (CSF) from the subarachnoid space through the wall of the superior sagital sinus and deposited in the venous return of the brain. The method of treating hydrocephalus with the system of this invention also constitutes a part of the invention.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in conjunction with the following drawings in which like reference numerals designate like elements and wherein:

FIG. 1 is a schematic view of a skull showing a preferred location of an implanted micro-system for the treatment of hydrocephalus in accordance with this invention;

FIG. 2 is a schematic, exploded, isometric view of an implantable micro-system for the treatment of hydrocephalus in accordance with this invention;

FIG. 3 is a schematic sectional view through a single microneedle of the system illustrated in FIG. 2, with the microneedle and associated microvalve assembled together and with the needle passing through dura mater in a patient's skull;

FIGS. 4A through 4E illustrate sequential steps in the fabrication of microneedles employed in the system of this invention; and

FIGS. 5A through 5G illustrate sequential steps in the fabrication of the preferred dome-shaped microvalves employed in this invention; and

FIG. 5H is an isometric view showing the configuration of the dome-shaped petal valve construction after the laser machining step of the valve forming process.

Claims

1. An implantable system for the treatment of hydrocephalus, said system including: (a) a plurality of hollow microneedles in a fixed array relative to each other, said microneedles being adapted to extend through dura mater and having a proximal end adapted to communicate with the interior of the brain on one side of the dura mater and a distal end adapted to communicate with the venous system in an area on a second side of the dura mater opposed to said one side; and(b) an array of microvalves associated with a proximal end of said microneedles, said microvalves being adapted permit the flow of cerebrospinal fluid (CSF) through the dura mater from the proximal end to the distal end of each microneedle to prevent an excessive pressure build up of CSF within the brain.

2. The system of claim 1, wherein said microvalves permit the flow of CSF through the microneedles based on the pressure differential between the subarachnoid space at the proximal end of the needles and the sinus at the distal end of said needles.

3. The system of claim 1, wherein said plurality of microneedles are formed in a fixed array on a first substrate and the microvalves are formed in fixed array on a second substrate, said first and second substrates being contiguous to each other to thereby communicate each microvalve on the second substrate with the proximal end of a corresponding microneedle.

4. The system of claim 3, wherein said microvalves each include an upstanding peripheral wall positioned within an opening in the first substrate that communicates with a proximal end of a corresponding microneedle.

5. The system of claim 4, wherein an outer surface of the peripheral walls of each microvalve frictionally engage internal surfaces defining the opening in the first substrate.

6. The system of claim 1, wherein said first and second substrates are secured together.

7. The system of claim 4, wherein said first and second substrates are secured together by thermal bonding.

8. The system of claim 1, wherein said microneedles are made of a polymer.

9. The system of claim 1, wherein said microneedles are biocompatible the human body.

10. The system of claim 1, wherein at least some of the microneedles are generally cone-shaped and have a recess in an outer surface thereof for receiving dura mater therein to help retain the system in proper position when implanted.

11. A method of treating hydrocephalus by implanting the system of claim 1 in the skull of a human with the hollow needles of the system extending through the dura mater of the skull.

12. The method of claim 11, including the step of implanting the system with a portion thereof below the dura mater being disposed solely in the subarachnoid space and with no portion of said system extending into the ventricular system.

13. The method of claim 11, wherein said system is implanted into a venous sinus.

14. The method of claim 11, wherein said system is implanted into the superior sagittal sinus.

15. The method of claim 13, wherein the system is implanted in the anterior one third of the sinus.

16. The method of claim 11, wherein a plurality of systems of claim 1 are implanted in the skull of a human with the hollow needles of the systems extending through the dura mater of the sinus.