Abstract: A catheter (1) has a distal side and a proximal side and includes a tip part (10) and a main body part (20) disposed proximal to the tip part (10), the main body part (20) includes a first layer (21) and a second layer (22), the first layer (21) contains 60% by mass or more of an ethylene-tetrafluoroethylene copolymer, the second layer (22) is disposed inside of the first layer (21) in a radial direction of the catheter (1) and contains 60% by mass or more of a polyamide resin, and a cantilever bending load of the tip part (10) is smaller than a cantilever bending load of the main body part (20).

Abstract: A catheter having a multilumenal tube surrounded by a slotted hypotube is provided. The catheter has a tube holder that houses the multilumenal tubing and slidably engages the hypotube, and has internal passages configured to receive one of more tubes from the multilumenal tube. The multilumenal tubing separates into one or more tubings, each comprising a lumen, such that the tubings exit the tube holder at different locations. The slotted hypotube slidably engages a key in the tube holder that prevents the multilumenal tubing from rotating relative to the tube holder and the one of more tubings that separate from the multilumenal tubing. Advantages provided by the slotted hypotube/tube holder assembly are described.

Abstract: A steerable sheath includes an inner liner extending from a proximal end to a distal end of the steerable sheath. The inner liner includes a non-deflectable portion and a deflectable portion. The steerable sheath includes a first pull wire positioned along a first helical path around the circumference of the inner liner from a proximal end to a distal end of the non-deflectable portion of the inner liner and along a first straight path from a proximal end of the deflectable portion to a distal end of the deflectable portion. The steerable sheath includes a second pull wire positioned along a second helical path around the circumference of the inner liner from the proximal end to the distal end of the non-deflectable portion and along a second straight path from the proximal end of the deflectable portion to the distal end of the deflectable portion.

Abstract: Catheter shafts and associated devices, systems, and methods are disclosed herein, A representative catheter in accordance with an embodiment of the disclosure includes a generally tubular outer structure and an inner structure surrounded by the outer structure. The inner structure surrounds a catheter lumen. The inner structure includes over-lapping edges such that, when the catheter is bent along its longitudinal axis, the over-lapping edges move relative to one another.

Abstract: A medical device includes an elongate shaft including a multifilar coil comprising a first strand and a second strand wound in the same winding direction, the multifilar coil comprising a first section having a first end and a second end wherein the first strand and the second strand are wound with identical pitch patterns between the first end and the second end of the first section, the multifilar coil further comprising a second section having a first end and a second end, wherein the first strand and the second strand are wound with different pitch patterns from each other between the first end and second end of the second section, and a polymeric tubular member coextending with the multifilar coil.

Abstract: Embodiments of bone and tissue resection devices are disclosed herein. In one embodiment, a device can include a stationary assembly having a housing, an elongated sleeve extending distally from the housing, and a cutting region disposed distal to the sleeve. The device can further include a drive assembly having a blade shaft extending through the elongated sleeve, the blade shaft having a distal tip with a cutting surface configured to extend into the cutting region when the drive assembly advances distally relative to the stationary assembly. The drive assembly can further include an oscillator coupled to the blade shaft and configured to engage with a source of continuous rotational motion to convert the continuous rotational motion into oscillating motion of the drive shaft. Further, the drive assembly can be configured to slidably couple to the stationary assembly to permit selective translation of the drive assembly relative to the stationary assembly.

Abstract: A neurovascular catheter having an angled distal tip has an elongate flexible tubular body with a proximal end, a distal end and a side wall defining a central lumen. The side wall has a helical coil. A tubular jacket surrounds the helical coil, and extending distally beyond the helical coil distal end to terminate in a catheter distal face. A tubular radiopaque marker is embedded in the tubular jacket in between the distal end of the coil and the distal face. The distal face resides on a plane which crosses a longitudinal axis of the tubular body at an angle within the range of from about 35 degrees to about 55 degrees. The marker has a proximal face that is approximately perpendicular to the longitudinal axis and a distal face that resides on a plane which crosses the longitudinal axis at an angle within the range of from about 35 degrees to about 55 degrees.

Abstract: A neurovascular catheter having an angled distal tip has an elongate flexible tubular body with a proximal end, a distal end and a side wall defining a central lumen. The side wall has a helical coil. A tubular jacket surrounds the helical coil, and extending distally beyond the helical coil distal end to terminate in a catheter distal face. A tubular radiopaque marker is embedded in the tubular jacket in between the distal end of the coil and the distal face. The distal face resides on a plane which crosses a longitudinal axis of the tubular body at an angle within the range of from about 35 degrees to about 55 degrees. The marker has a proximal face that is approximately perpendicular to the longitudinal axis and a distal face that resides on a plane which crosses the longitudinal axis at an angle within the range of from about 35 degrees to about 55 degrees.

Abstract: Devices, systems and methods are described herein to provide improved steerability for delivering a prosthesis to a body location, for example, for delivering a replacement mitral valve to a native mitral valve location. Disclosed are a number of features that can improve steerability or release of the prosthesis into the body location.

Abstract: Double-lumen infusion catheter including: a shaft having proximal section, distal section, and intermediate section therebetween; first and second lumens extending along a length of the shaft and having arc shaped wall therebetween; and an inflatable member provided distally to intermediate section, and over the distal section. First lumen has cross section larger than cross section of second lumen and is configured to receive a guidewire therethrough and allow fluid flow via an unobstructed portion of first lumen. Unobstructed portion is formed along guidewire outer surface, between guidewire outer surface and inner wall of first lumen, and extends from an inlet at proximal end of intermediate section to an outlet at distal end of intermediate section. First lumen is narrowed to approximate a first diameter in shaft proximal and distal sections, and is widened to approximate a second diameter greater than first diameter in the shaft intermediate section.

Abstract: A cochlear including a housing, an antenna, a stimulation processor operably connected to the antenna, and an electrode array, operably connected to the stimulation processor, including a flexible body defining a longitudinal axis, a proximal region and a distal region, a plurality of electrically conductive contacts on the flexible body, and at least one stiffener within the flexible body.

Abstract: Systems and devices for endovascular treatment of intracranial aneurysms are described. Various configurations of coiled implants may be used as stenting devices or aneurysm coils. The implants include one or more filaments wound about a longitudinal axis to form a generally tubular shape. Lateral flexibility of the implants may be manipulated by, for example, adjusting a pitch between adjacent filaments, using different materials for the filaments, employing different filament cross-sectional shapes, grouping filaments into pluralities of varying flexibilities, and nesting inner coils within outer coils.

Abstract: A mixed coil catheter includes a hollow inner liner defining a lumen, having an exterior surface, and defining a middle point, a single support cord coiled around the exterior surface of the inner liner starting from an intermediate point in a distal direction up to a support end plane and then reversed in the proximal direction proximally away from the support end plane at least past the middle point of the inner liner, having a maximum outer diameter, and forming an end wall at the support end plane, and an outer liner covering the inner liner and the support cord to fix the support cord in place.

Abstract: A neurovascular aspiration catheter has an elliptical distal aspiration port. The catheter has an elongate flexible tubular body comprising a distal port and a side wall defining a central lumen in communication with the port. A tubular radiopaque marker is embedded in the side wall and has a proximal face and a distal face. The distal face of the radiopaque marker inclines at an angle within a range of from about 45 degrees to about 80 degrees relative to the longitudinal axis of the central lumen. The distal port comprises an elliptical opening with an area that is at least about 105% of a cross-sectional area of the central lumen.

Abstract: Retraction guidewires are disclosed, including retraction guidewires configured to transition from an elongate configuration for delivery to a treatment site through an organ wall to a deployed configuration for retraction of the organ wall, for example. The deployed configuration includes a stem portion and a dome portion having a distal end and a proximal end, the stem portion extending proximally from the distal end of the dome portion.

Abstract: A wall (39) of a catheter (38) (a) includes a braided portion (41) having an outer surface (45), an inner surface (47), and a braided interior (53) between the outer and inner surfaces (45, 47), and (b) is shaped to define first and second longitudinally-running channels (27a, 27b) therethrough. A distal portion of the catheter (38) is shaped to define first and second lateral openings (26a, 26b). An angle between (a) a first line (76) running between the first and second lateral openings (26a, 26b), and (b) a second line (78) that is parallel to a central longitudinal axis of the catheter (38) when the catheter (38) is straight, is between 30 and 150 degrees.

Abstract: Methods of providing sympathetic nerve blocks comprise inserting a portion of a catheter into a subject. A distal end of the catheter is positioned on a lateral side of at least one vertebra of a vertebral column of the subject proximate to a portion of a sympathetic nervous system of the subject. A medication is supplied through the catheter to effect a sympathetic nerve block in the subject. Methods of alleviating pain in lower extremities of subjects comprise inserting a portion of a catheter into a subject and supplying a medication through the catheter. Catheters and catheter assemblies may be used in administering such sympathetic nerve blocks. Catheters and catheter assemblies may be used in administering medication to one or more of a peripheral nervous system of a subject and a spinal cord of a subject.

Abstract: An enhanced flexibility neurovascular catheter is provided, such as for distal neurovascular access or aspiration. The catheter includes an elongate flexible body, having a proximal end, a distal end and a side wall defining a central lumen. A distal zone of the side wall includes an outer jacket surrounding a helical coil, and the outer jacket is formed from a plurality of tubular segments positioned coaxially about the coil. A proximal one of the tubular segments has a durometer of at least about 60D, and a distal one of the tubular segments has a durometer of no more than about 35D. An axially extending filament within the side wall extends at least about the most distal 10 cm of the length of the catheter. The axially extending filament serves as a tension support and resists elongation of the catheter wall under tension, such as when the catheter is being proximally retracted through tortuous vasculature.

Abstract: In one embodiment of the invention, an apparatus for performing surgical procedures is disclosed including a flexible entry guide tube, and a first steering device. The flexible entry guide tube has one or more lumens extending along its length from a proximal end to substantially at or near a distal end. At least one of the one or more lumens is an instrument lumen with open ends to receive a flexible shaft of a surgical tool to perform surgery near the distal end of the flexible entry guide tube. The first steering device is insertable into the instrument lumen to shape the flexible entry guide tube as it is inserted through an opening in a body and along a path towards a surgical site. The apparatus may further include a flexible locking device to couple to the flexible entry guide tube and selectively rigidize the flexible entry guide tube to hold its shape. The flexible entry guide tube may be steered by remote control with one or more actuators.

Abstract: A balloon catheter comprises a balloon, an outer tube connected to a proximal end of the balloon, an inner tube disposed inside the outer tube and having a distal end attached to a distal end of the balloon, a protruded-depressed portion formed on an outer periphery of the inner tube, and a core wire disposed between the outer tube and the inner tube. The core wire has a bulged portion sandwiched between the outer tube and a depressed portion of the protruded-depressed portion. The balloon catheter can transmit a force from the core wire to both the outer tube and the inner tube regardless of whether the force is generated by pushing or pulling a proximal end portion of the balloon catheter. Additionally, the core wire can move appropriately to maintain the flexibility of the balloon catheter even when the balloon catheter bends.

Abstract: In various embodiments of the present disclosure, a surgical catheter is provided. The present disclosure provides a catheter shaft that includes a distal portion and a proximal portion. The proximal portion comprises a handle operably connected to the distal portion of the elongated structure. The distal portion three radially positioned polymeric layers. At least two of the layers include chemically dissimilar polymers and at least one of the three layers includes functionalized polyvinylidene fluoride (PVDF).

Abstract: Medical devices, perfusion systems, and methods for detecting a pressure within a space in a subject and for perfusion of fluid into a space in a subject. The space may be a fluid-filled space, or a space that is depleted of fluid due to an obstruction to fluid flow into the space. Methods for forming the medical devices.

Abstract: A stent indwelling device includes a guide catheter and a pusher catheter. The guide catheter includes: a core section; an outer layer section surrounding an outer circumference of the core section; a stent protection section disposed between the core section and the outer layer section, being longer than a dimension of a tube stent, having stiffness resisting compression inward in a radial direction perpendicular to a longitudinal axis of the guide catheter, and having flexibility in a direction in which the guide catheter is curved; and a stopper configured to allow expansion of the stent protection section in a direction along the longitudinal axis and restrict movement of the stent protection section in the direction with respect to the core section.

Abstract: A catheter delivery device for a self-expanding stent is described. The delivery device includes a distal catheter component and a distal sheath that releases the stent by moving proximally relative to the distal catheter component and the stent. A proximal catheter shaft including a tube and a pull wire within a lumen of the tube may be provided, the pull wire being attached to the distal sheath such that pulling the pull wire proximally relative to the tube pulls the distal sheath proximally to release the stent progressively. A casing tube may be provided to surround the catheter shaft, the casing tube having a distal end that receives telescopically a proximal end of the distal sheath.

Abstract: A sheath for deploying a medical device to a target site in the body of a patient. A tubular inner liner has a proximal portion, a distal portion, and an outer surface. An outer jacket has a proximal portion, a distal portion, and an inner surface. A reinforcing member is received within a length of the outer jacket. The outer jacket is positioned longitudinally around the inner liner and bonded to the outer surface of the liner. The reinforcing member, which may be a triaxial braid, or an encapsulated longitudinal reinforcing wire, extends along the outer jacket length and is configured for inhibiting elongation of the sheath upon deployment of the device.

Abstract: A variable stiffness catheter having two concentric coils. A first coil is fixed with relation to the body of the catheter and a second coil is able to rotate in the space between adjacent turns of the first coil. The second coil translates axially in response to being rotated. When the second coil is advanced to its distal position, the stiffness is maximized. When the second coil is refracted proximally, the stiffness of the coil is reduced.

Abstract: An apparatus produces a tubular structure having a longitudinal axis and at least one form extending helically inward from the structure relative to the longitudinal axis. The apparatus includes an extruder including at least two spaced apart extrusion die surfaces adapted to extrude plastic state material therethrough. At least one extrusion die has at least one nonplanar channel having facing nonplanar surfaces configured and disposed such that during extrusion of the material through the at least one extrusion die, material flowing into the channel creates the at least one form. The channel surfaces direct material flow such that the at least one form and the structure exiting the extruder and last contacted by the at least one die of the extruder collectively helically rotate about the longitudinal axis.

Abstract: A non-compliant medical balloon, where the non-compliant medical balloon may be changed from a deflated state to an inflated state by increasing pressure within the balloon, is made with a first fiber layer, a second fiber layer over said first fiber layer such that the fibers of the first fiber layer and the fibers of the second fiber layer form an angle and a binding layer coating the first fiber layer and said second fiber layer. The interior surface area of the non-compliant medical balloon remains unchanged when the balloon changes from a deflated state to an inflated state.

Abstract: Methods are provided for reducing one or more dimensions of individual pieces of biomass; treating biomass, such as size-reduced biomass; changing a molecular structure of a biomass material; and, optionally, subjecting the biomass to a primary process to form a product. The methods include processing biomass materials using a screw extrusion process, and treating the biomass material with a screw extrusion process in size-reduction and treating steps.

Abstract: A method for manufacturing a catheter member having at least one lumen is disclosed herein. The method includes, winding a sacrificial coil over a mandrel in a first direction and winding a reinforcement coil over the sacrificial coil in a second direction. A polymer is then laminated over the sacrificial coil and the reinforcement coil. After the polymer is laminated, the mandrel is removed and the sacrificial coil is removed to thereby form the catheter member having the lumen.

Abstract: A device and method for treating bone fractures/lesions using an inflatable body is provided. The inflatable body includes a balloon having a substantially flat horizontal surface for quick easy insertion into bone beneath the fracture so as to align misaligned fragments of the fracture and/or to collapsed bone. The body has a shape and size to compress at least a portion of the cancellous bone to form a cavity in the cancellous bone and/or to restore the original position of the outer cortical bone, if fractured or collapsed. The inflatable body has a stylet attached to it's distal end so that once the inflatable body is deflated it can be twisted about the stylet to have a smaller profile so as to be easily withdrawn from the bone.

Abstract: An indicator assembly for use with a non-vascular catheter device. The indicator assembly includes: a first retainer secured to a catheter tube, the first retainer being an indwelling retainer which is deployed within a non-vascular lumen or cavity of the body; a second retainer secured to the catheter tube, the second retainer deployed outside the human body; and an indicator located outside the body on the catheter tube between the first retainer and the second retainer. The first retainer and the second retainer are configured to maintain substantially the same position with respect to each other on the tube and the indicator is configured to signal a change in position with respect to either the first or the second retainer, thereby indicating a change in the length of a stoma.

Abstract: The present disclosure provides a strong, flexible catheter shaft for use in a catheter system. The flexible catheter shaft includes a braided polyimide tube including one or more outer layers of material of varying flexibility. The flexible catheter shaft provides a shaft having sufficient stiffness and kink resistance to allow an operator to advance an electrode basket connected to the flexible catheter shaft through a guide catheter to a target ablation site without causing vessel trauma. The distal tip of the flexible catheter shaft is designed to have sufficient flexibility to reduce any risk of kicking out a guide catheter when tracking the electrode basket around turns into side branches or bifurcations in the vasculature of a patient and includes a distal spring coil.

Abstract: A method of manufacturing a catheter includes wrapping a sheet of material having an inner adhesive layer around a reinforcement member. The catheter manufactured is a resilient tube having a channel extending therethrough. The resilient tube has an adhesive inner layer and a bendable reinforcement member which extends through the channel.

Abstract: Provided is a medical instrument which can reliably protect a sub-lumen and a method of manufacturing the medical instrument. In such a medical instrument, a catheter includes a resin tubular main body (sheath), in which a main lumen and a sub-lumen which is disposed on an outer peripheral side of the main lumen and extends along a longitudinal direction of the main lumen, are formed; a reinforcement layer which is disposed between the main lumen and the sub-lumen and surrounds the main lumen; and a wire which is disposed further on an outer peripheral surface side of the tubular main body than the sub-lumen and is disposed so as to surround the outer periphery of the main lumen. The wire is embedded in the tubular main body and supports the outer peripheral surface of the tubular main body.

Abstract: Medical device (10) for delivering therapeutic material to a patient. The device comprises an access sheath (12) having a proximal section (18) extending to a distal section (20). A working lumen (22) is formed in the proximal and distal sections. The distal section has a plurality of side ports (48) formed therethrough in fluid communication with the working lumen. The distal section has a deflection section (42) actuatable to bend at an angle for positioning the side ports in the patient. A needle assembly (14) is configured to move within the working lumen between a retracted position and an extended position. In fluid communication with a central lumen is a plurality of needles (80). The needles are disposed within the access sheath in the retracted position and the needles extend through the side ports outwardly from the access sheath in the extended position.

Abstract: Methods for easy, atraumatic access to areas of the vasculature that are otherwise difficult to access, using steerable guide catheters constructed with components that are selected to provide optimal navigability, torque transfer, and push ability for a variety of typical percutaneous access routes. The catheter wall thickness in the deflecting segment of the guide catheter is about 1 French (? mm) or less, and includes a slotted deflection tube, and this construction allows a very tight turning radius which in turn enables guide catheter access to regions of the vasculature that are otherwise inaccessible.

Abstract: Disclosed is an access catheter, having a distal segment which is moveable from a reduced outside diameter for positioning at a target site, and an enlarged outside diameter to create an enlarged internal working lumen. In one application, the catheter is configured for use as an intracranial aspiration catheter. Methods are also disclosed.

Abstract: Distal access balloon guide catheter system and methods for delivering implantable devices, catheters, or substances in or near and/or restoring flow through body lumens, such as blood vessel lumens, or inflating balloons affixed to the distal end of the guide catheter system are described. A Distal access balloon guide catheter having a proximal region, an optional medial region of intermediate flexibility, and distal region possessing high flexibility, high resistance to kinking and a large lumen to wall thickness ratio. The balloon is inflated by means of a kink-resistant secondary lumen embedded within the walls of the balloon guide catheter system tubing.

Abstract: A catheter includes an inner layer, a braid, an outer layer, and a distal tip. A recessed region having a first side and a second side is formed in a distal end portion of the braid, a length of the first side being longer than the sum of a wire width of a first wire and a distance between two adjacent first wires, a length of the second side being longer than the sum of a wire width of a second wire and a distance between two adjacent second wires. The distal tip is bonded to the inner layer in the recessed region. By providing the recessed region, the number of peaks formed in the distal end portion of the braid is made smaller than that in the existing case.

Abstract: A catheter with an elastic reinforcement layer allows its catheter tube to expand from a native diameter to an expanded diameter. In this respect, a device or implant with a larger diameter than that of the catheter tube's native diameter size can be passed through the catheter without damage.

Abstract: In various embodiments of the present disclosure, a surgical catheter is provided. The present disclosure provides a catheter shaft that includes a distal portion and a proximal portion. The proximal portion comprises a handle operably connected to the distal portion of the elongated structure. The distal portion three radially positioned polymeric layers. At least two of the layers include chemically dissimilar polymers and at least one of the three layers includes functionalized polyvinylidene fluoride (PVDF).

Abstract: An intravenous catheter has a tip portion, an extendable portion and a proximal portion attached to a hub. The extendable portion has a refracted position and an extended position. A wire may be incorporated in the intravenous portion. The wire may have a receiver disposed in the tip portion. An extender tool is insertable and removable from the catheter. The extender is dimensioned to engage the receiver upon insertion into said catheter and lengthen the extendable portion of said catheter to said extended position when inserted.

Abstract: A method of manufacturing a catheter assembly generally includes providing a catheter shaft having an outer layer and an inner reinforcing layer; removing at least a portion of the outer layer from a length of the distal end of the catheter shaft in order to expose a distal segment thereof; providing an inner jacket segment; axially engaging the inner jacket segment with an interior surface of the distal segment of the catheter shaft; providing an outer jacket segment around at least the exposed exterior region of the distal segment of the catheter shaft; and bonding the distal segment of the catheter shaft to the inner jacket segment and the outer jacket segment.

Abstract: The disclosure relates to medical tubes and methods of manufacturing medical tubes. The tube may be a composite structure made of two or more distinct components that are spirally wound to form an elongate tube. For example, one of the components may be a spirally wound elongate hollow body, and the other component may be an elongate structural component also spirally wound between turns of the spirally wound hollow body The tube need not be made from distinct components, however. For instance, an elongate hollow body formed (e.g., extruded) from a single material may be spirally wound to form an elongate tube. The elongate hollow body itself may in transverse cross-section have a thin wall portion and a relatively thicker or more rigid reinforcement portion. The tubes can be incorporated into a variety of medical circuits or may be employed for other medical uses.

Abstract: The invention primarily is directed to a medical tubing adapted for insertion into a body tissue or cavity and method of manufacturing different variations of the tubing along a length of the tubing. The tubing comprises a plurality of individual, discrete, generally ring-shaped elements arranged in series and fused or bonded together forming a continuous tubular structure. The ring-shaped elements may include a combination of flexible and rigid ring-shaped elements assembled along different portions or sections of the tubular structure. In another aspect of the invention, the medical tubing may further comprise a secondary lumen and a pull wire to control the tubular structure. In another aspect of the invention, the ring-shaped elements may vary in diameter and/or composition in different portions or sections of the tubular structure.

Abstract: Introducer sheath (10,30,40) having a flexible kink-resistant distal tip portion (26,32,42). A multilayer sheath structure is used, with an inner tube (12) such as PTFE having a coil (14) of wire wound therearound. A first length of outer tubing (20) such as of nylon is inserted over most of the coil-wound inner tube (12) in a manner exposing a distal length of coil-wound inner tube. A second length of outer tubing (22) with a softer durometer than first outer tubing length (20), is inserted over the exposed coil-wound inner tube and extends for a slight distance beyond the end of the coil. During heat application, the outer tubing lengths (20, 22) are melted to bond to each other and to flow between the spacings of the coil turns to bond to the roughened outer surface of the inner tube (12). The distal tip region corresponding to the second tubing length is flexible and is kink-resistant due to the coil (14).

Abstract: Tubing for use in gastrointestinal applications includes a hollow tube and a spring positioned inside the tube. The spring is corrosion resistant and helps to prevent kinking of the tubing when the tubing is bent. An encapsulant may be positioned over the spring. The spring may be co-extruded with the tubing.

Abstract: The present application relates to method of arresting telescopic endwise relative movement in a medical device between an end portion of an elongate member, preferably being a cylinder, and an end portion of a tube, preferably being a cylindrical tube, that receives the end portion of the elongate member. The method is of particular use in the construction of stent delivery systems. In one embodiment, the method comprises providing a length of deformable blocking material; imparting relative endwise movement to draw the blocking material, into the gap and reversing the direction until the blocking material length suffers deformation.

Abstract: A catheter comprises a flexible polymer catheter body including a proximal shaft section and a distal working section, a wire support structure embedded within the distal working section of the catheter body, a proximal adapter mounted to the proximal shaft section of the catheter body, and a wire disposed within the catheter body. The wire has a proximal end and a distal end. The proximal end of the wire being operably connected to the proximal adapter, and the distal end of the wire is anchored to the wire support structure.