The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 03, 1991
Filed:
Dec. 29, 1989
Neal E Fearnot, West Lafayette, IN (US);
Richard B Sisken, West Lafayette, IN (US);
Medical Engineering and Development Institute, Inc., West Lafayette, IN (US);
Abstract
An extremely small diameter epidural catheter is disclosed which is both flexible and kink-resistant when flexed. The catheter includes a tubular sheath or tube having a passageway therein for the delivery of fluids to biological tissue. Positioned in the passageway is a coil which is expansion-fitted therein to form a composite wall structure which is extremely flexible and kink-resistant. This composite wall structure is utilized to form a catheter having an extremely small outside diameter in a range of 0.010' to 0.032' for delivering acceptable levels of fluid volume. The coil comprises a plurality of closely spaced turns extending from the proximal to almost the distal end thereof. About the distal end of the coil is a number of loosely coupled or relaxed turns which adds further flexibility to the distal end of the catheter. The tubular sheath of the catheter comprises a high tensile or flexural strength material which does not rupture or tear when the catheter is bent or flexed. Maintaining the ratio of the outside diameter of the wire coil to the cross-sectional diameter of the individual turns within a range of 4 to 10 prevents the tubular sheath from either rupturing or kinking when the catheter is flexed or bent.