Abstract: A laser welding apparatus and system for surgically bonding tissue together provides a beam of coherent light at a wavelength corresponding to a specific tissue thickness at which full absorption of the laser energy occurs, and adjusts the energy of the laser beam in response to tissue temperature throughout the tissue thickness to prevent the tissue temperature from either exceeding a predetermined limit or varying outside a predetermined range. Preferably, the coherent light beam has a center wavelength of 1.9 .mu.m, and is variable between 1.85 and 1.91 .mu.m.

Abstract: An intra aortic balloon pumping device comprises a pumping balloon, an attached inflation catheter, a supporting member which is disposed within and extends from the catheter into the balloon. The balloon membrane of the invention resists the formation of membrane folds in the tail section of the balloon. This characteristic of the balloon membrane is believed to result from the addition of tension to the balloon membrane. Tension may be applied to the membrane by ensuring that the portion of the support member which is disposed within the balloon is equal to the length of the outer curve of the balloon wall such that it resides on an outer curve of the wall. Alternatively, tension may be applied by extending the support member within the balloon.

Abstract: A blood pump having a toroidal shaped chamber concentrically positioned around a cylindrically shaped hydraulic pump. The toroidal chamber has two toroidal shaped portions, one portion having a substantially rigid external wall and the other having an external wall formed of a flexible membrane. The chamber has an inlet and output port suitable for connection to a blood flow supply. The flexible wall portion of the toroidal chamber is enclosed within a hydraulic chamber, fluidically coupled to the hydraulic pump. The hydraulic pump is controlled so that an increase of pressure in the hydraulic chamber results in a decrease of volume in the toroidal chamber, thus providing for pumping of the blood through that portion of the chamber. The toroidal shape provides for optimal non-coagulating flow, while the rigid wall of the chamber, together with the flexible membrane provide for membrane motion along only one axis, normal to the circumference of the toroid, preventing damage to the membrane.

Abstract: A liquid delivery system, particularly useful as an implantable micro-pump for delivering insulin or other drugs, comprises a collapsible reservoir for the feed liquid to be delivered, which reservoir is enclosed by a rigid housing, a container for a drive liquid, and a pump selectively pumping the drive liquid either from the drive liquid container into the rigid housing between its inner face and the collapsible reservoir for pumping the feed liquid therefrom, or out of the rigid housing into the drive liquid container for refilling the collapsible reservoir with feed liquid.