Drill guide apparatus for perpendicular perforation of the cranium

• US 5,207,681 A
• Filed: 10/19/1989
• Issued: 05/04/1993
• Est. Priority Date: 10/26/1987
• Status: Expired due to Fees

• Current Assignee: Neurodynamics Incorporated
• Original Assignee: Neurodynamics Incorporated
• Inventors: Hariri, Robert J., Ghadjar, Fathali G., Ghajar, Jamshid B. G.
• Primary Examiner(s): Thaler, Michael H.
• Application Number:
  US07/424,034
• Time in Patent Office: 1,293 Days
• Field of Search: 606/80, 606/96, 606/179, 606/180, 408/95, 408/97, 408/112
• US Class Current: 606/96
• CPC Class Codes: A61B 17/1695 Trepans or craniotomes, i.e. specially adapted for drilling thin bones such as the skull

Abstract

An apparatus and method for drilling an orifice in a human cranium at an angle of substantially 90° to a plane defined by a tangent to the surface of the cranium at the orifice. The apparatus comprises a ring structure adapted to guide and support a drill, the ring structure comprising a retaining member configured for engagement with a flexible member such as a spring and a sleeve member configured for insertion within the retaining member and operatively associated therewith to form a support assembly. The support assembly is capable of a restricted degree of vertical, slideable movement within a tubular member. The apparatus further comprises a tubular member, adjacent and external to the ring structure, adapted to guide and support the support assembly; a flexible member adjacent the support assembly for restricting vertical movement thereby within the tube; and support structure, the support structure being adapted to rest unsecured upon the cranium. The method of the invention comprises positioning the drill guide upon the patient'"'"'s cranium such that the support structure, the tubular member and the support assembly are related to each other and to the cranium so as to guide the drill through the cranium in a direction perpendicular to a plane defined by a tangent to the surface of the cranium at the orifice and drilling through said cranium until the tip of the drill bit passes therethrough and stops rotation rapidly once it has penetrated the surface.

Claims

1. An apparatus for accurately and reproducibly guiding drill means during the formation of an orifice in a human cranium, wherein said orifice extends at an angle of substantially 90°

to an imaginary plane defined by a tangent to said cranium at said orifice, said apparatus comprising;

(a) ring means comprising a retaining member configured and adapted for engagement with a terminal portion of a spring means and a sleeve member, insertable within said retaining member and operatively associated therewith, said sleeve member comprising an open tubular body portion having a first end and a second end and an integrally formed circular flange member located along an outer peripheral portion of said first end, said ring means capable of a restricted degree of vertical, slideable movement within tubular means and fabricated from a self-lubricating thermoplastic composition to facilitate the movement thereof;

(b) tubular means adjacent and external to said ring means, adapted to guide and support said ring means, said tubular means having means for directing said vertical, slideable movement of said ring means, said directing means comprising channel means formed integral with a base portion of said tubular member entirely around an inner surface thereof and extending into a central bore defined by said tubular member, said channel means configured and adapted for supporting a lower portion of said spring means and having an inner wall portion adjacent said central bore separated from an outer wall portion formed by an inner surface of said tubular member by a base portion positioned substantially perpendicularly to and formed integral with both said inner and said outer wall portions, wherein said inner wall portion extends a sufficient distance within said bore so as to terminate beyond said second end of said open tubular body portion of said sleeve member to prevent any interference between said second end and said inner wall during said vertical slideable movement of said ring means within said tubular means;

(c) spring means located adjacent said body portion of said sleeve member and capable of resisting vertical movement of said ring means toward said base portion of said tubular means caused due to downward pressure exerted by said drill means during the formation of said orifice, said spring means encased within said tubular means

(d) a collar member surrounding to an upper surface of a bit portion of said drill means so as to facilitate rotation of said bit portion within said ring means, said collar member having grooved portions extending substantially therethrough to facilitate insertion of said bit portion within said collar member, each said grooved portion comprising, along an inner surface thereof, at least one tang configured and adapted for engaging an outer surface of said bit portion; and

(e) a plurality of leg members extending from and formed integrally with a lower surface of said base portion of said tubular means, said leg members adapted to rest unsecured upon an arcuate portion of said cranium, said tubular means, said ring means and said leg members being related to each other and to said cranium so as to guide said drill means through said arcuate portion in a direction perpendicular to an imaginary plane defined by a tangent to said cranium at said arcuate portion.

2. The apparatus of claim 1 wherein each of said plurality of legs terminates in a free end, said free ends forming a polygon defining a plane, said sleeve means guiding said drill means in a direction perpendicular to said plane and through the geometric center of said polygon.

3. The apparatus of claim 2 wherein said support means comprises three legs of equal length and wherein an equilateral triangle is formed by said free ends of said legs.

4. The apparatus of claim 1 further comprising a cap member for interlocking engagement with an upper surface of said tubular means, said cap member having an open bore portion to permit passage of said drill means therethrough.

9. The apparatus of claim 1 further comprising an annular cap member configured for interlocking engagement with an upper peripheral surface of said tubular means, said cap member having an open bore portion to permit passage of said drill means therethrough.

5. An apparatus for accurately and reproducibly guiding drill means during the formation of an orifice in a human cranium, wherein said orifice extends at an angle of substantially 90°

to an imaginary plane defined by a tangent to said cranium at said orifice, said apparatus comprising;

(a) a retaining ring, configured and adapted for engagement with a terminal portion of a flexible spring and fabricated from a self-lubricating thermoplastic composition;

(b) a sleeve fabricated from a self-lubricating thermoplastic composition, said sleeve comprising an open tubular body portion having a first end and a second end and an integrally formed circular flange located along an outer peripheral portion of said first end, said sleeve further insertable within said retaining ring to form a support assembly, said support assembly capable of a restricted degree of vertical, slideable movement within tubular means;

(c) tubular means, adjacent and external to said support assembly, said tubular means adapted to guide and support said sleeve and said retaining ring, said tubular means having means for directing said vertical, slideable movement of said support assembly, said directing means comprising channel means formed integral with a base portion of said tubular member entirely around an inner surface thereof and extending into a central bore defined by said tubular member, said channel means configured and adapted for supporting a lower portion of said flexible spring and having an inner wall portion adjacent said central bore separated from an outer wall portion formed by an inner surface of said tubular member by a base portion positioned substantially perpendicularly to and formed integral with both said inner and said outer wall portions, wherein said inner wall portion extends a sufficient distance within said bore so as to terminate beyond said second end of said open tubular body portion of said sleeve member to prevent any interference between said second end and said inner wall during said vertical slideable movement of said ring means within said tubular means;

(d) a spring located adjacent said support assembly and capable of resisting vertical movement of said support assembly toward said base portion of said tubular means caused due to downward pressure exerted by said drill means during the formation of said orifice, said spring encased within said tubular means;

(e) a collar member surrounding an upper surface of a bit portion of said drill means so as to facilitate rotation of said bit portion within said sleeve said collar member having grooved portions extending longitudinally therethrough to facilitate insertion of said bit portion within said collar member, each said grooved portion comprising, along an inner surface thereof, at least one tang configured and adapted for engaging an outer surface of said bit portion; and

(f) three legs of equal length extending from and formed integrally with a lower surface of said base portion of said tubular means, each of said legs terminating in a free end, said free ends forming an equilateral triangle, said legs adapted to rest unsecured upon an arcuate portion of said cranium;

said tubular means, said support assembly and said legs being related to each other and to said cranium so as to guide said drill means through said arcuate portion in a direction perpendicular to an imaginary plane defined by a tangent to said cranium at said arcuate portion.

6. The apparatus of claim 5 wherein said tubular means further comprises a plurality of substantially vertical indented portions along an outer circumferential periphery thereof, said indented portions configured and adapted to facilitate non-slip gripping of said apparatus.

7. The apparatus of claim 6 wherein said tubular means is molded from an engineering thermoplastic selected from among Delrin®

, ABS and an acrylic.

8. The apparatus of claim 5 wherein said self-lubricating thermoplastic composition is selected from the group consisting of Teflon®

and Nylex®

.

10. The apparatus of claim 5 which further comprises a drill adapted for rotating said bit portion, at least a portion of said drill configured for insertion within said open tubular body portion of said sleeve.

11. The apparatus of claim 10 wherein said drill is selected from among electric, hydraulic and pneumatic surgical drills.

12. An apparatus for accurately and reproducibly guiding drill means during the formation of an orifice in a human cranium, wherein said orifice extends at an angle of substantially 90°

to an imaginary plane defined by a tangent to said cranium at said orifice, said apparatus comprising;

(a) a retaining ring, configured and adapted for engagement with a terminal portion of a flexible spring and fabricated from a self-lubricating thermoplastic composition;

(b) a sleeve fabricated from a self-lubricating thermoplastic composition, said sleeve comprising an open tubular body portion having a first end and a second end and an integrally formed circular flange located along an outer peripheral portion of said first end, said sleeve further insertable within said retaining ring to form a support assembly, said support assembly capable of a restricted degree of vertical, slideable movement within tubular means;

(c) tubular means, adjacent and external to said support assembly, said tubular means adapted to guide and support said sleeve and said retaining ring, said tubular means having means for directing said vertical, slideable movement of said support assembly, said directing means comprising channel means formed integral with a base portion of said tubular member entirely around an inner surface thereof and extending into a central bore defined by said tubular member, said channel means configured and adapted for supporting a lower portion of said flexible spring and having an inner wall portion adjacent said central bore separated from an outer wall portion formed by an inner surface of said tubular member by a base portion positioned substantially perpendicularly to and formed integral with both said inner and said outer wall portions wherein said inner wall portion extends a sufficient distance within said bore so as to terminate beyond said second end of said open tubular body portion of said sleeve member to prevent any interference between said second end and said inner wall during said vertical slideable movement of said ring means within said tubular means;

(d) a spring located adjacent said support assembly and capable of resisting vertical movement of said support assembly toward said base portion of said tubular means caused due to downward pressure exerted by said drill means during the formation of said orifice;

(e) a collar member surrounding an upper surface of a bit portion of said drill means so as to facilitate rotation of said bit portion within said sleeve, said collar member having grooved portions extending longitudinally therethrough to facilitate insertion of said bit portion within said collar member, each said grooved portion comprising, along an inner surface thereof, a tang configured and adapted for engaging an outer surface of a bit portion of said drill means; and

(f) three legs of equal length extending from and formed integrally with a lower surface of said base portion of said tubular means, each of said legs terminating in a free end, said free ends forming an equilateral triangle, said legs adapted to rest unsecured upon an arcuate portion of said cranium;

said tubular means, said support assembly and said legs being related to each other and to said cranium so as to guide said drill means through said arcuate portion in a direction perpendicular to an imaginary plane defined by a tangent to said cranium at said arcuate portion.