Body tissue aspiration cannula

#1. Field of the Invention

#The present invention relates generally to a surgical aspiration cannula. In particular, the invention relates to a body tissue aspiration cannula having improved feel during use, may be chemical or steam sterilized, and which is more resistant to, bending, twisting, or kinking. The invention also relates to a novel hub design for an aspiration cannula which aids in insertion and removal of the vacuum source.

#2. Description of Related Art

#FIG. 1 is a side elevation view of an embodiment of the present invention.

#FIG. 2 is an enlarged, fragmentary or cut away, side elevation view of the cannula showing the lumen and the hub attachment.

#FIG. 3 is a partial perspective view of the hub portion showing a second embodiment of a hub portion of the cannula.

#The body tissue aspiration cannula of the present invention consists of a tubular portion made of a polymer material and a hub portion for attaching the tubular portion to a vacuum source. The polymer for the tubular portion needs to be a surgical grade polymer biocompatable for use in humans. Primarily, this means that the polymer should be biocompatible, for example, as demonstrated by passing or qualifying to pass the criteria of FDA 21 CFR 177.1520 or USP Class VI. The flexural modulus of the polymer selected for the tubular portion is also extremely important in balancing the use and flexibility of the tubular portion between the often too hard and the soft flexible tubes. Finally, the selected polymer for both the tubular portion and hub portion should be readily steam sterilizeable. That is, capable of repeated steam sterilization without substantial degradation of the polymer comprising either the tubular or hub portion of the cannula.

#The flexural modulus of the polymer used in the tubular portion and hub portion of the present invention is measured by standard ASTM test D790 at 1% secant, 0.05 in/min, using Method A and measured in parts per square inch.

#In one embodiment of the present invention, the flexural modulus of the tubular portion is between about 100,000 psi and 225,000 psi. In another embodiment, it is between 110,000 psi and 200,000 psi. In yet another embodiment, it is between 120,000 psi and 180,000 psi and in still another embodiment; it is between 130,000 psi and 150,000 psi.