Abstract: A phacoemulsification needle tip of the present invention has a continuous cutting edge formed at an inner surface of a cylindrical needle shaft. The cutting edge is formed by cutting the needle shaft at an angle and beveling the exterior surface of at least the forward portion of the needle. The beveling of the exterior surface of the needle tip moves the cutting edge from an exterior diameter of the needle to an interior diameter of the needle. The needle tip having the shape of the present invention has improved cutting ability, accuracy, and threading ability which are important for phacoemulsification procedures. The needle tip is also less likely to puncture sensitive membranes of the eye during surgery. The needle tip may also include an internal beveled surface at a trailing portion of the cutting edge.

Abstract: A hypodermic needle according to the present invention includes a hollow shaft having a substantially cylindrical inner surface and a substantially cylindrical outer surface. The needle includes a beveled surface extending between and connecting the inner surface and the outer surface of the needle tip. A cutting edge of the needle is formed between the beveled surface and the internal surface of the needle. The hypodermic needle avoids trauma, tearing, and other unnecessary tissue damage during penetration of tissue and during threading of the probe through blood vessels, tunnel incisions or cavities. An alternative embodiment of the hypodermic needle has a cutting edge which includes a rounded or blunted section at a trailing portion of the cutting edge.

Abstract: In a process for preparing tissue for microscopic examination which process includes the steps of fixing a specimen of tissue, dehydrating the fixed specimen, clearing the dehydrated specimen, and impregnating the cleared specimen with paraffin, ultrasonic energy is applied to the specimen in each of the processing steps to reduce the total preparation time. Also, the time required to stain a specimen of tissue is reduced when ultrasonic energy is applied to the specimen while immersed in the stain.