摘要:
An internal combustion engine is described that includes an expansion cylinder adjacent to a first combustion cylinder (or power cylinder). Combustion gases from the first cylinder are directed to the expansion cylinder to act on the piston in the expansion cylinder. The expansion cylinder has a larger bore (i.e. larger diameter piston) and/or a longer stroke than the first cylinder. The longer stroke also results in a much larger crankshaft arm resulting in a significantly improved mechanical advantage (i.e. torque). In addition, the expansion cylinder includes a check valve that is designed to automatically open the expansion chamber to atmosphere if a negative pressure develops due to the varying amount of exhaust gases at different speeds. In one embodiment, two power cylinders can be connected to one expansion cylinder.
摘要:
A stent/graft especially designed to be used in a minimally invasive surgical procedure for treating an abdominal aortic aneurysm (AAA) comprises an innermost tubular structure of a length (L1) formed by braiding a relatively few strands of shape memory alloy wire. The pick and pitch of the braid are such as to provide relative large fenestrations in the tubular wall. A portion of the innermost tubular structure of a length L2 L2 does not block blood flow to the renal arteries while the portion L2 prevents the aneurysm to grown and burst.
摘要:
A catheter deliverable stent/graft especially designed to be used in a minimally invasive surgical procedure for treating a variety of vascular conditions such as aneurysms, stenotic lesions and saphenous vein grafts, comprises an innermost tubular structure and at least one further tubular member in coaxial arrangement. In one embodiment, the innermost tubular structure is of a length (L1) and is formed by braiding a relatively few strands of highly elastic metallic alloy. The pick and pitch of the braid are such as to provide relative large fenestrations in the tubular wall that permit blood flow through the wall and provide the primary radial support structure. A portion of the innermost tubular structure of a length L1 is surrounded by a further braided tubular structure having relatively many strands that substantially inhibit blood flow through the fenestrations of the innermost tubular structure. The composite structure can be stretched to reduce the outer diameter of the stent/graft, allowing it to be drawn into a lumen of a delivery catheter. The catheter can then be advanced through the vascular system to the site of treatment and then released, allowing it to self-expand against the vessel wall. Various optional embodiments are disclosed that allow one skilled in the art to tailor the design to the specific application.
摘要:
A collapsible medical device and associated methods of occluding an abnormal opening in, for example, a body organ, wherein the medical device is shaped from plural layers of a heat-treatable metal fabric. Each of the fabric layers is formed from a plurality of metal strands and the assembly is heat-treated within a mold in order to substantially set a desired shape of the device. By incorporating plural layers in the thus-formed medical device, the ability of the device to rapidly occlude an abnormal opening in a body organ is significantly improved.
摘要:
The present invention provides an improved vascular occlusion device having improved flexibility and retention of the type fabricated from braided tubular metal fabric having an expanded preset configuration and an elongated collapsed reduced diameter configuration for delivery through a catheter to a treatment site and shaped to create an occlusion of an abnormal opening in a body organ or vessel, the woven metal fabric having a memory property whereby the medical device tends to return to said expanded preset configuration when unconstrained. The device further including at least one disk portion adjacent a body cylindrical portion formed from the fabric and having a transition diameter between the disk and cylindrical portion, significantly smaller than the diameter of the disk and the diameter of the cylindrical portion.
摘要:
Embodiments of the present invention provide an improved vascular occlusion device for occlusion of a passageway, cavity, or the like. According to one embodiment, a medical device for occluding a left atrial appendage is provided. The medical device includes a first portion having at least one plane of occlusion that is configured to be positioned outside of the left atrial appendage, and a second portion having at least one plane of occlusion that is configured to be at least partially positioned within a cavity defined by the left atrial appendage.
摘要:
A multi-layer occluder for treating a target site within the body is provided. The occluder may include first and second layers. For example, the first layer may include braided strands of metallic material, and the second layer may include braided strands of polymeric material. At least one of the first or second layers may be configured to facilitate thrombosis.
摘要:
A stent/graft especially designed to be used in a minimally invasive surgical procedure for treating an abdominal aortic aneurysm (AAA) comprises an innermost tubular structure of a length (L1) formed by braiding a relatively few strands of shape memory alloy wire. The pick and pitch of the braid are such as to provide relative large fenestrations in the tubular wall. A portion of the innermost tubular structure of a length L2 L2 does not block blood flow to the renal arteries while the portion L2 prevents the aneurysm to grown and burst.
摘要:
A collapsible medical device and associated methods of occluding an abnormal opening in, for example, a body organ, wherein the medical device is shaped from plural layers of a heat-treatable metal fabric. Each of the fabric layers is formed from a plurality of metal strands and the assembly is heat-treated within a mold in order to substantially set a desired shape of the device. By incorporating plural layers in the thus-formed medical device, the ability of the device to rapidly occlude an abnormal opening in a body organ is significantly improved.
摘要:
Implantable occlusion devices that include one or more flanges extending from a tubular body are disclosed. The flange or flanges may assist in retention of the device within a vessel, cavity, appendage, etc. At least one flange on the occlusion device may include a concave surface proximate one end of a body. Because of the shape of the flange, e.g., its concavity, the occlusion device may resist dislocation due to e.g., the forces generated within the left atrial appendage during atrial fibrillation.