Abstract: An actuator includes a ceramic body having a base and an array of tube-shaped or blade-pair-shaped piezoelectric or electrostrictive ceramic elements defining an enclosure and integral with the base. A first electrode contacts the inner surfaces of walls of the elements, while a second electrode contacts the wall outer surfaces. The actuator is driven for d.sub.31 mode or d.sub.15 mode vibration of the walls. The wall vibration is transmitted to a desired medium via a vibration transmission means, e.g., a compliant polymer filler material of Shore A30 to Shore D75 filling the enclosure and bonded to the walls. Alternatively, a stiff cover plate may be used to transmit the tube wall vibration to a desired medium. An acoustic sensor device is also described.

Abstract: Methods for fabricating a conformable composite acoustic transducer panel including a conformable composite body having upper and lower planar faces and upper and lower thin, flexible electrodes bonded to the upper and lower faces, respectively. The composite body includes an array of individual piezoelectric or electrostrictive ceramic elements extending normal to the upper and lower faces and through the composite body from the upper face to the lower face to electrically contact the electrodes. Stiff integral face plates are bonded to the side surfaces of the elements at their upper and lower ends. Alternatively, a conformable, stiff, voided polymer matrix is bonded to the element sides over their entire length. Flexible circuit boards may be bonded to the electrodes to provide electrical contact thereto.

Abstract: A transducer including a ceramic body having a base and an array of tube-shaped piezoelectric or electrostrictive ceramic elements integral with the base. A first electrode contacts the tube wall inner surface, while a second electrode contacts the tube wall outer surface and is electrically isolated from the first electrode and from the lower surface of the transducer. The first electrode extends onto the transducer lower surface for electrical connection to a power source for driving the transducer across the tube walls for d.sub.31 mode vibration of the tube walls. A stiff cover plate may be used to transmit the tube wall vibration to a desired medium. The ceramic base may be removed if an electrically insulating layer is provided between the elements at the lower surface of the transducer. The insulating layer and tube wall upper edges then electrically isolate the second electrode from the first electrode and the transducer lower surface.

Abstract: A laparoscopic instrument assembly for use with a removable tip. The shaft between the removable tip and the external, body or handle portion of the instrument includes a rod moving axially within a sheath to transmit the manipulation of the handle portion to actuate the tip. Both the sheath and the rod are removable from the handle for cleaning of the instrument. Thus, after use, the shaft may be readily disassembled from the handle, the shaft and handle portion sterilized, and the shaft and handle readily reassembled for reuse of the instrument. Alternatively, a non-removable tip may be provided as part of a shaft-tip unit.

Abstract: A low profile ionizing surface (LPIS) for use as a static eliminator or charging means in an apparatus within which insulative material is contacted by apparatus surfaces. The LPIS includes a low profile fibrous network of randomly disposed, electrically conductive, 0.5-50 .mu.m by 1/8"-3" microfibers in electrically conductive contact with one another across the network, providing microfiber ionizing points across the network surface. The thickness of the network is significantly less than the average length of the microfibers. An adhesive layer fixes the network to a surface of the machine. Thus, when the network is grounded or electrically charged, static charge is removed from the material as it passes across or near the exposed surface of the network. The LPIS may be in the form of a peel-and-stick sheet or tape, or a kit may be provided to install the LPIS in an apparatus.

Abstract: A catheter for insertion into a bodily conduit, especially an artery. The catheter comprises a shaft (26) having at least one lumen (24) for delivery of a fluid inflation media and a double balloon (12) including an array (20) of a plurality of inflatable secondary chambers (22) radially disposed in a cylindrical array around an inflatable primary chamber (16). Each of the secondary chambers (22) shares a common wall (38) with adjacent secondary chambers (22) and a common wall (14) with the primary chamber (16). The secondary chambers (22) are inflated by an array of channels (32) which are separated from each other by webs (40). One or more of the secondary chambers (22) may be in communication with a pressure transducer for measurement of the resistance of, e.g., a stenosis to dilation by the balloon (12). Alternately, a triple balloon (60) has inner secondary chambers (22a) and outer secondary chambers (22b).

Abstract: A small diameter ionizing cord for use in an apparatus through which insulative material flows or is propelled. The ionizing cord has an outer surface and includes three or more strands of electrically non-conductive fibers braided to form a smooth cord having an effective diameter of about 0.5-6 mm. At least one of the strands is a static control strand including a multiplicity of electrically conductive microfibers being in electrically conductive communication with one another along the length of the strand. The microfibers are selected to provide a multiplicity of ionizing points disposed along the length of the cord and exposed at or extending minimally above the outer surface such that, when the strand is electrically grounded or electrically charged, air between the ionizing points and the material passing the outer surface is sufficiently ionized to remove static charge from the material or to attract or repel the material to or from the apparatus surface.

Abstract: A conformable composite acoustic transducer panel including a conformable composite body having upper and lower planar faces and upper and lower thin, flexible electrodes bonded to the upper and lower faces, respectively. The composite body includes an array of individual piezoelectric or electrostrictive ceramic elements extending normal to the upper and lower faces and through the composite body from the upper face to the lower face to electrically contact the electrodes. Stiff integral face plates are bonded to the side surfaces of the elements at their upper and lower ends. Alternatively, a conformable, stiff, voided polymer matrix is bonded to the element sides over their entire length. Flexible circuit boards may be bonded to the electrodes to provide electrical contact thereto. Methods for fabricating the transducer panel are also disclosed.

Abstract: A flextensional cover plate for redirecting the vibrational displacement of terminal ends of at least one pair of piezoelectric or electrostrictive ceramic bender elements vibrating toward and away from each other. The flextensional cover plate includes at least one flexible pleat configured to be bondable to terminal ends of the bender elements such that the bender element vibrational displacement is converted to vibrational displacement of said cover plate in a direction normal to said element vibrational displacement. The preferred flextensional cover plate is configured such that the amplitude of the cover plate vibrational displacement is greater than that of the bender element vibrational displacement.

Abstract: A drainage catheter for draining fluids from an internal body part and a process of using the catheter wherein the catheter is subject to development of encrustations of the fluids being drained. The catheter comprises an outer flexible tubular member with a drainage lumen disposed therein. An inner flexible tubular member is slidably disposed within the outer tubular member. The inner tubular member is positioned in the outer tubular member in a predetermined location relative to the outer tubular member whereby withdrawal of the inner tubular member can cause encrustations to be broken up and removed without withdrawing the catherer from the body part being drained.

Abstract: A chair stabilizing device for rotatable attachment to a ground level, horizontally extending leg member portion of, for example, a lawn or beach chair. The device includes a stabilizing base and a gripping member fixed to the base. A slit in the portion of the gripping member not fixed to the base provides access to a central opening sized and shaped to receive the horizontally extending leg member portion. The gripping member is sufficiently flexible to permit installation of the device by inserting the leg member portion through the slit into the central opening. The gripping member is also sufficiently firm to grip and hold the leg member portion within the central opening and to hold the base parallel to the leg member portion during use of the chair. The base, on installation of the device, extends sufficiently outward to the side of the chair to prevent tipping of the chair to the side during use.

Abstract: A slip-layered balloon catheter for insertion into a bodily conduit, especially an artery. The catheter comprises a shaft (21) having at least one lumen (26) for delivery of a fluid inflation media and a slip-layered balloon (12) made up of a plurality of layers with a low-friction substance between the layers. The low-friction substance causes the layers to slide readily relative to one another, softening the balloon while maintaining its strength. Optionally, the balloon includes a plurality of slip-layered segments radially disposed about the balloon wall, and separated by lengthwise ridges joining the layers of each segment together. Also optionally, an elastic sleeve surrounds the balloon wall to improve refoldability of the balloon.

Abstract: A low profile ionizing surface (LPIS) for use as a static eliminator or charging means in an apparatus within which insulative material is contacted by apparatus surfaces. The LPIS includes a low profile fibrous network of randomly disposed, electrically conductive, 0.5-50 .mu.m by 1/8"-3" microfibers in electrically conductive contact with one another across the network, providing microfiber ionizing points across the network surface. The thickness of the network is significantly less than the average length of the microfibers. An adhesive layer fixes the network to a surface of the machine. Thus, when the network is grounded or electrically charged, static charge is removed from the material as it passes across or near the exposed surface of the network. The LPIS may be in the form of a peel-and-stick sheet or tape, or a kit may be provided to install the LPIS in an apparatus.

Abstract: A calibrated guidewire for use in determining the magnitude of arterial occlusions in the body and a method of using the guidewire. The guidewire includes a flexible sleeve having a distal end and a hemispherical tip having a flat inner surface. A multifilar flexible coil is disposed between the distal end of the sleeve and the tip. The coil has a uniform outer diameter and is formed by two sets of different wires, one of which is radiotransparent and the other of which is radiopaque. The spacings between each of the sets is identical and is defined by the widths of each of the sets to provide regularly spaced radiotransparent areas of indicia that are observable as a fluoroscopic image to enable the user measure of the magnitude of an occlusion in a tubular structure in the body. The multifilar construction extends the entire length of the coil between the sleeve and the tip.

Abstract: A kink resistant balloon catheter for insertion into a bodily conduit. The catheter (10) includes a shaft (20), a radiopaque distal tip (35), a dilatation balloon (33) between the shaft and the distal tip, and a removable core wire (40). The shaft includes a kink resistant, cross-wound multifilar (CWMF) coil (21) enclosed by a polymeric sleeve (22) and defining a central lumen (28) for delivery of a fluid inflation medium for inflating the balloon. A fixed core wire (36) interconnects the CWMF coil and the distal tip. In a method for widening constricted bodily passages using the novel balloon catheter, the removable core wire is inserted to assist positioning of the catheter, and is removed to permit rapid inflation and deflation of the balloon.

Abstract: An infusion catheter including an elongated catheter body, and an infusion section at its distal end for delivery of therapeutic fluid to bodily passages. The infusion section includes an outer tube and an inner tube concentric with the outer tube, each tube having a multiplicity of ports therethrough. The inner tube delimits a central, fluid delivery lumen. The inner tube is uniformly spaced apart from the outer tube to provide an annular passageway, the radial depth of the passageway being sufficient to permit fluid flow therewithin. Each of the ports through the outer tube provides fluid communication between the annular passageway and the exterior of the catheter, while each of the ports through the inner tube provides fluid communication between the central lumen and the annular passageway. Thus, therapeutic fluid can flow from the central lumen through the annular passageway to the catheter exterior.

Abstract: An exchange guidewire for positioning and exchanging medical catheters within a bodily passage during a medical procedure which uses an endoscope. The guidewire includes a wire of a length sufficient for exchange of the catheters through the endoscope, a radiopaque flexible coil fixed to the distal end of the wire, and a pattern of stripes endoscopically discernable along the guidewire. Optionally, a shrink-wrap, low-friction sleeve jackets the guidewire, the pattern of indicia being endoscopically discernable along the length of the jacketed guidewire. The position of the exchange guidewire indicia relative to the endoscope optical lens may be monitored by viewing the stripes endoscopically. A method of positioning and exchanging medical catheters within a bodily passage during a medical procedure which uses an endoscope is also disclosed.

Abstract: A single phase superconducting oxide ceramic material in the form of highly oriented platelets, and a process for the production thereof. The process involves calcining in a non-reducing atmosphere a homogeneous mixture of stoichiometric proportions of suitable precursor materials. The calcination temperature is below the peritectic melt temperature of the superconducting material, and is at or above a temperature and for a time sufficient to effect partial melting of at least one of the precursor materials to a degree sufficient to effect diffusion of at least one of the precursor materials throughout the mixture. The calcination vessel is not wetted by melts of the precursor materials at the calcination temperature. The calcined material is then annealed in a non-reducing atmosphere. A typical material produced by the process is YBa.sub.2 Cu.sub.3 O.sub.x superconducting material, at a calcination temperature of about 976.degree.-982.degree. C.