Abstract: An arterio-venous graft (16) is provided with a constriction device (20) near its arterial end. The constriction device (20) is used to reduce the flow through the AV graft under normal conditions and to relieve the constriction when high flow through the AV graft is required, such as for vascular access for hemodialysis.

Abstract: An arterio-venous graft (16) is provided with a constriction device (20) near its arterial end. The constriction device (20) is used to reduce the flow through the AV graft under normal conditions and to relieve the constriction when high flow through the AV graft is required, such as for vascular access for hemodialysis.

Abstract: Apparatus and methods are provided comprising an implantable non-hydraulic ring that encircles and provides a controllable degree of constriction to an organ or duct and an external control that powers and controls operation of the ring. The ring includes a rigid dorsal periphery that maintains a constant exterior diameter, and a compliant constriction system that reduces intolerance phenomena. A high precision, energy efficient mechanical actuator is employed that is telemetrically powered and controlled, and maintains the ring at a selected diameter when the device is unpowered, even for extended periods. The actuator provides a reversible degree of constriction of the organ or duct, which is readily ascertainable without the need for radiographic imaging. Methods of use and implantation also are provided.

Abstract: An arterio-venous graft (16) is provided with a constriction device (20) near its arterial end. The constriction device (20) is used to reduce the flow through the AV graft under normal conditions and to relieve the constriction when high flow through the AV graft is required, such as for vascular access for hemodialysis.

Abstract: An arterio-venous graft 16 is provided with a constriction device 20 near its arterial end. The constriction device 20 is used to reduce the flow through the AV graft under normal conditions and to relieve the constriction when high flow through the AV graft is required, such as for vascular access for hemodialysis.

Abstract: An arterio-venous graft (16) is provided with a constriction device (20) near its arterial end. The constriction device (20) is used to reduce the flow through the AV graft under normal conditions and to relieve the constriction when high flow through the AV graft is required, such as for vascular access for hemodialysis.

Abstract: Apparatus and methods are provided comprising an implantable non-hydraulic ring that encircles and provides a controllable degree of constriction to an organ or duct and an external control that powers and controls operation of the ring. The ring includes a rigid dorsal periphery that maintains a constant exterior diameter, and a compliant constriction system that reduces intolerance phenomena. A high precision, energy efficient mechanical actuator is employed that is telemetrically powered and controlled, and maintains the ring at a selected diameter when the device is unpowered, even for extended periods. The actuator provides a reversible degree of constriction of the organ or duct, which is readily ascertainable without the need for radiographic imaging. Methods of use and implantation also are provided.

Abstract: Apparatus and methods are provided comprising an implantable non-hydraulic ring that encircles and provides a controllable degree of constriction to an organ or duct and an external control that powers and controls operation of the ring. The ring includes a rigid dorsal periphery that maintains a constant exterior diameter, and a compliant constriction system that reduces intolerance phenomena. A high precision, energy efficient mechanical actuator is employed that is telemetrically powered and controlled, and maintains the ring at a selected diameter when the device is unpowered, even for extended periods. The actuator provides a reversible degree of constriction of the organ or duct, which is readily ascertainable without the need for radiographic imaging. Methods of use and implantation also are provided.

Abstract: An arterio-venous graft (16) is provided with a constriction device (20) near its arterial end. The constriction device (20) is used to reduce the flow through the AV graft under normal conditions and to relieve the constriction when high flow through the AV graft is required, such as for vascular access for hemodialysis.

Abstract: An arterio-venous graft (16) is provided with a constriction device (20) near its arterial end. The constriction device (20) is used to reduce the flow through the AV graft under normal conditions and to relieve the constriction when high flow through the AV graft is required, such as for vascular access for hemodialysis.

Abstract: An arterio-venous graft (16) is provided with a constriction device (20) near its arterial end. The constriction device (20) is used to reduce the flow through the AV graft under normal conditions and to relieve the constriction when high flow through the AV graft is required, such as for vascular access for hemodialysis.

Abstract: Apparatus and methods are provided comprising an implantable non-hydraulic ring that encircles and provides a controllable degree of constriction to an organ or duct and an external control that powers and controls operation of the ring. The ring includes a rigid dorsal periphery that maintains a constant exterior diameter, and a compliant constriction system that reduces intolerance phenomena. A high precision, energy efficient mechanical actuator is employed that is telemetrically powered and controlled, and maintains the ring at a selected diameter when the device is unpowered, even for extended periods. The actuator provides a reversible degree of constriction of the organ or duct, which is readily ascertainable without the need for radiographic imaging. Methods of use and implantation also are provided.

Abstract: An arterio-venous graft 16 is provided with a constriction device 20 near its arterial end. The constriction device 20 is used to reduce the flow through the AV graft under normal conditions and to relieve the constriction when high flow through the AV graft is required, such as for vascular access for hemodialysis.

Abstract: An arterio-venous graft (16) is provided with a constriction device (20) near its arterial end. The constriction device (20) is used to reduce the flow through the AV graft under normal conditions and to relieve the constriction when high flow through the AV graft is required, such as for vascular access for hemodialysis.

Abstract: Apparatus and methods are provided comprising an implantable non-hydraulic ring that encircles and provides a controllable degree of constriction to an organ or duct and an external control that powers and controls operation of the ring. The ring includes a rigid dorsal periphery that maintains a constant exterior diameter, and a compliant constriction system that reduces intolerance phenomena. A high precision, energy efficient mechanical actuator is employed that is telemetrically powered and controlled, and maintains the ring at a selected diameter when the device is unpowered, even for extended periods. The actuator provides a reversible degree of constriction of the organ or duct, which is readily ascertainable without the need for radiographic imaging. Methods of use and implantation also are provided.

Abstract: Apparatus and methods are provided comprising an implantable non-hydraulic ring that encircles and provides a controllable degree of constriction to an organ or duct and an external control that powers and controls operation of the ring. The ring includes a rigid dorsal periphery that maintains a constant exterior diameter, and a compliant constriction system that reduces intolerance phenomena. A high precision, energy efficient mechanical actuator is employed that is telemetrically powered and controlled, and maintains the ring at a selected diameter when the device is unpowered, even for extended periods. The actuator provides a reversible degree of constriction of the organ or duct, which is readily ascertainable without the need for radiographic imaging. Methods of use and implantation also are provided.