12212 results about "Helix" patented technology

An integrated scaffold for bone tissue engineering has a tubular outer shell and a spiral scaffold made of a porous sheet. The spiral scaffold is formed such that the porous sheet defines a series of spiral coils with gaps of controlled width between the coils to provide an open geometry for enhanced cell growth. The spiral scaffold resides within the bore of the shell and is integrated with the shell to fix the geometry of the spiral scaffold. Nanofibers may be deposited on the porous sheet to enhance cell penetration into the spiral scaffold. The spiral scaffold may have alternating layers of polymer and ceramic on the porous sheet that have been built up using a layer-by-layer method. The spiral scaffold may be seeded with cells by growing a cell sheet and placing the cell sheet on the porous sheet before it is rolled.

One embodiment is a stimulation lead including a lead body comprising a longitudinal surface, a distal end, and a proximal end; and multiple electrodes disposed along the longitudinal surface of the lead body near the distal end of the lead body. The multiple electrodes include multiple segmented electrodes with each of the segmented electrodes having an exterior surface, an interior surface opposite the exterior surface, a proximal end, and a distal end. At least one of the segmented electrodes includes one or more of a) at least one channel formed in the segmented electrode and extending from the proximal end to the distal end of the segmented electrode, b) an arcuate groove formed in at least one of the distal end surface or the proximal end surface, or c) a notch formed in the segmented electrode and extending from the proximal end to the distal end of the segmented electrode.

A device for brain stimulation includes a lead having a longitudinal surface, a proximal end and a distal end; and a plurality of electrodes disposed along the longitudinal surface of the lead near the distal end of the lead. The plurality of electrodes includes at least four segmented electrodes having exposed surfaces where each exposed surface has a center point. The center points of the at least four segmented electrodes are disposed on a substantially helical path about the longitudinal surface of the lead.

A system for modifying a heart valve annulus includes a helically helical anchored annuloplasty device delivered to the annulus via an elongated delivery member. The helical anchors of the devices disclosed herein are rotated into the valve annulus along an anchor guide by using a driver that is movably disposed in the delivery member. A tether is disposed within an inner channel of the helical anchor and a locking device is used to secure the annuloplasty device after the valve annulus has been modified. The annuloplasty device can be delivered to the annulus using, traditional surgical approach or a minimally invasive or catheter based methods.

A antenna array (20) includes a plurality of periodic or aperiodic arranged sub-arrays (22). Each sub-array (22) includes a plurality of antenna elements (32) arranged in the form of a spiral (30). The sub-arrays (22) can comprise various spiral shapes to provide the required physical configuration and operational parameters to the antenna array (20). The elements (32) of each sub-array (22) are arranged to minimize the number of such elements (32) that intersect imaginary planes perpendicular to the spiral and passing through the spiral center. Such an orientation of the elements (32) minimizes grating lobes in the antenna pattern.

A system for modifying a heart valve annulus includes a helically helical anchored annuloplasty device delivered to the annulus via an elongated delivery member. The helical anchors of the devices disclosed herein are rotated into the valve annulus along an anchor guide by using a driver that is movably disposed in the delivery member. A tether is disposed within an inner channel of the helical anchor and a locking device is used to secure the annuloplasty device after the valve annulus has been modified. The annuloplasty device can be delivered to the annulus using, traditional surgical approach or a minimally invasive or catheter based methods.

A method for manufacturing a lead includes forming an elongated multi-lumen conductor guide defining a central stylet lumen and a plurality of conductor lumens arranged around the stylet lumen. The multi-lumen conductor guide is twisted to form at least one helical section where the plurality of conductor lumens each forms a helical pathway around the stylet lumen. Each of the helical pathways of the at least one helical section has a pitch that is no less than 0.04 turns per centimeter.

A spinal fixation device combines an open-headed anchor member, such as a bone screw or a hook, with a closure member to thereby clamp a spinal fixation rod to the anchor member. The anchor member has spaced apart arms forming a rod receiving channel. The arms have arm extensions or tabs connected to main portions of the arms by weakened regions to enable the tabs to be broken-off or separated after the rod is clamped. The closure member and inner surfaces of the arms and tabs have helical anti-splay guide and advancement interlocking flanges formed thereon which cooperate to prevent splaying the arms and extensions as the closure member is advanced into the rod receiving channel. The flanges have anti-splay contours which can be formed on load flanks or stab flanks of the flanges. The load flanks can be oriented in such a manner as to aid in the anti-splay characteristics of the flanges or to control the proportioning of axial stresses between the flanges.

A catheter includes a segment having a longitudinal axis. The segment has a helical coil extending coaxially with the longitudinal axis. The coil has a plurality of turns along a length of the axis. Adjacent turns have opposing surfaces joined by bridging members tying at least selected ones of the adjacent turns.

A device for capturing an embolus within a vessel of a patient's body has at least one helix made of a mesh material. The at least one helix has a plurality of turns helically arranged around a longitudinal axis. The mesh material has a plurality of pores therein and the pores have a size ≧120 μm. The at least one helix includes a plurality of panels wherein the panels are movable from a collapsed state to an expanded state when placed within a vessel. The mesh material is made of a self-expanding material such as nickel titanium in one embodiment. In another embodiment, the device has a double helix arrangement.

An improved crimping mechanism well-suited for use with stented prosthetic heart valves. The crimping mechanism includes a plurality of jaws configured for linear non-rotational movement toward a central axis. A rotational plate is formed with a plurality of spiral grooves or tracks for engaging the jaws. Rotational movement of the spiral tracks produces linear movement of the jaws. Nesting of the inner ends of the jaws permits each to be acted on along different radial lines while their inner faces move together evenly to reduce the crimping aperture in a smooth fashion. The crimping mechanism is particularly well-suited for use with stented prosthetic heart valves, such as a prosthetic aortic valve, though it can also be applied to other stented heart valves, venous valves, and even stent grafts which tend to be fairly large.

Methods and apparatuses for positioning medical devices onto (or close to) a desired portion of the interior wall of an internal channel, such as for scan imaging, for photodynamic therapy and/or for optical temperature measurement. In one embodiment, a catheter assembly has a distal portion that can be changed from a configuration suitable for traversing the internal channel to another configuration suitable for scan at least a spiral section of the interior wall of an internal channel, such as an artery. In one example, the distal portion spirals into gentle contact with (or close to) a spiral section of the artery wall for Optical Coherence Tomography (OCT) scanning. The spiral radius may be changed through the use of a guidewire, a tendon, a spiral balloon, a tube, or other ways.

A coil for the treatment of vascular aneurysms is disclosed. The coil is formed from filamentary members interlaced to form a three-dimensional substrate. The substrate is deformable between a collapsed state wherein it fits within a catheter, and an expanded state, which it assumes once deployed from the catheter into the vascular aneurysm. The three-dimensional shapes of the substrate include flat sheets biased into a helix or a tubular forms biased into figure eight loops, helical loops or a sinusoid. Bioactive characteristics may be imparted to the coil through the use of coatings or materials that provoke a healing response in living tissue.

A method of writing product servo sectors to a disk of a disk drive is disclosed. A plurality of spiral tracks are written to the disk, wherein each spiral track comprises a high frequency signal interrupted at a predetermined interval by a sync mark. During the product servo writing process, the sync marks in the spiral tracks are read to generate a coarse timing recovery measurement, and the high frequency signal in the spiral tracks is read to generate a fine timing recovery measurement. The coarse and fine timing recovery measurements are processed to synchronize a servo write clock used to write the product servo sectors to the disk. In one embodiment the control circuitry within the disk drive synchronizes the servo write clock by reading the spiral tracks, and in an alternative embodiment an external product servo writer synchronizes the servo write clock by reading the spiral tracks.

The invention relates to a tissue anchor which is an open helix of biocompatible material having a slope of from 0.5 to 10 turns per centimeter, a length from 3 to 75 millimeters, a diameter of from 1.5 to 11 millimeters, and an aspect ratio of from about 3 to about 5 to 1. The anchor can have a head which is capable of securing or clamping tissue together, such as holding a suture to secure a ligament or tendon to bone. The anchor can also have a head which causes an inward, compressive loading for use in fastening bone to bone, orthopedic plates to bone, or cartilage to bone. The head may be an integral member and may include a self-reinforcing wedge which joins the helix to the head. Further, the elongate member, or filament that forms the helix may have a tapering diameter along its length.

This invention provides a small diameter snare device and device for thrombus removal consisting of a hollow, elongate, thin-walled outer sheath constructed from polymer, at least at a distal part thereof. A single central core wire extends through the entire length of the sheath. The outer diameter of the core wire is sized close to the inner diameter of the sheath while allowing for axial sliding, in order to maximize the support to the body portion of the snare device. The distal end of the core wire has a tapered section of reduced diameter or cross section to provide a “guidewire-like” flexibility to the distal portion of the device. A second wire (or wires) of about fifty percent or less of the inner diameter of the sheath is (are) shaped to form a snare loop or radially extended tool tip that is attached to the distal most portion of the central core wire. The snare loop is typically circular or oval shaped and can also be multiplanar (for example, a twisted, figure eight shape) so as to increase the ability to ensnare and capture objects. The tool tip can be a planar or multi-planar, proximally directed structure that, when deployed, is adapted to engage the thrombus from behind after piercing the thrombus with the sheath while the tool tip is retracted.

In an embodiment, an antenna for a medical device, e.g., an implantable medical device (IMD), comprises an electrically conductive wire that spirals to form a three-dimensional shape of a rectangular cuboid. In another embodiment, the antenna comprises an electrically conductive wire that spirals to form a three-dimensional shape of an elliptical cylinder, an oval cylinder, an elongated pentagonal prism, an elongated hexagonal prism, or some other shape where the longitudinal diameter of the antenna is greater than the lateral diameter of the antenna. The antennas are sized to fit within a portion of a header of the medical device. Such antennas are designed to provide increased antenna gain and antenna bandwidth.

A bi-center drill bit includes pilot and reaming blades affixed to a body at azimuthally spaced locations. The blades have PDC cutters attached at selected positions. In one aspect, the pilot blades form a section having length along the bit axis less than about 80 percent of a diameter of the section. In another aspect, selected pilot blades and corresponding reaming blades are formed into single spiral structures. In another aspect, shapes and positions of the blades and inserts are selected so that lateral forces exerted by the reaming and the pilot sections are balanced as a single structure. Lateral forces are preferably balanced to within 10 percent of the total axial force on the bit. In another aspect, the center of mass of the bit is located less than about 2.5 percent of the diameter of the bit from the axis of rotation. In another aspect, jets are disposed in the reaming section oriented so that their axes are within about 30 degrees of normal to the axis of the bit. In another aspect, the reaming blades are shaped to conform to the radially least extensive, from the longitudinal axis, of a pass-through circle or a drill circle, so the cutters on the reaming blades drill at the drill diameter, without contact to the cutters on the reaming blades when the bit passes through an opening having about the pass-through diameter.