摘要:
At least one aspect is directed to a totally artificial heart, and at least another aspect is directed to a method of controlling blood flow in a patient. The totally artificial heart may include a first rotary pump having an input to receive blood and an output to provide blood to a patient's lungs, a second rotary pump having an input to receive blood and an output to provide blood to the patient's body, a first sensor associated with the first rotary pump, a second sensor associated with the second rotary pump, and a control system coupled to the first sensor, the second sensor, the first rotary pump and the second rotary pump and configured to control characteristics of the first rotary pump and the second rotary pump based on signals received from at least one of the first sensor and the second sensor such that an average flow of blood through the second rotary pump is greater than an average flow of blood through the first rotary pump.
摘要:
The invention provides a transcutaneous energy transfer device having an external primary coil and an implanted secondary coil inductively coupled to the primary coil, electronic components subcutaneously mounted within the secondary coil and a mechanism which reduces inductive heating of such components by the magnetic field of the secondary coil. For one embodiment of the invention, the mechanism for reducing inductive heating includes a cage formed of a high magnetic permeability material in which the electronic components are mounted, which cage guides the flux around the components to prevent heating thereof. For an alternative embodiment of the invention, a secondary coil has an outer winding and either a counter-wound inner winding or an inner winding in the magnetic field of the outer winding. For either arrangement of the inner coil, the inner coil generates a magnetic field substantially canceling the magnetic field of the outer coil in the area in which the electronic components are mounted.
摘要:
The invention provides a transcutaneous energy transfer device having an external primary coil and an implanted secondary coil inductively coupled to the primary coil, electronic components subcutaneously mounted within the secondary coil and a mechanism which reduces inductive heating of such components by the magnetic field of the secondary coil. For one embodiment of the invention, the mechanism for reducing inductive heating includes a cage formed of a high magnetic permeability material in which the electronic components are mounted, which cage guides the flux around the components to prevent heating thereof. For an alternative embodiment of the invention, a secondary coil has an outer winding and either a counter-wound inner winding or an inner winding in the magnetic field of the outer winding. For either arrangement of the inner coil, the inner coil generates a magnetic field substantially canceling the magnetic field of the outer coil in the area in which the electronic components are mounted.
摘要:
A transcutaneous energy transfer device is provided which has a magnetic shield covering the primary winding of the device to reduce sensitivity of the device to conducting objects in the vicinity of the coils and to increase the percentage of magnetic field generated by the primary coil which reaches the secondary coil. This shield is preferably larger than the primary coil in all dimensions and is either formed of a high permeability flexible material, for example a low loss magnetic material in a flexible polymer matrix, with perforations formed in the material sufficient to permit ventilation of the patient's skin situated under the shield, or the shield may be formed of segments of very high permeability material connected by a flexible, porous mesh material.
摘要:
Spinal implants and methods for spinal stabilization and/or fusion are provided. Exemplary implants described herein can be configured for delivery to a facet joint to stabilize and/or fuse the facet joint, and can optionally be anchored within the pedicle for added fixation. The implant can optionally include a fusion-promoting bioactive material thereby providing a single device capable of spinal stabilization and/or fusion. Furthermore, a method of placing such an implant within a facet joint is provided.
摘要:
A magnetically operated blood pump includes a rotor with an impeller that rotates within a housing, and the housing fastens to a driver that preferably electromagnetically controls the speed and disposition of the impeller in response to sensed conditions. The impeller and housing constitute a disposable assembly in which permanent magnets embedded in the impeller stabilize its position to maintain pumping tolerances in at least one dimension, and also couple to external fields to rotate the impeller. In one embodiment concentric arrangements of cylinder magnets passively maintain radial centering, while coils in the driver are actuated to simultaneously produce a rotational torque and to correct axial or tilt displacements. In a preferred embodiment of this type, sensors around the periphery detect axial displacement and/or tilt as the impeller turns, while the drive circuit responds to the sensor signal to produce compensating phase changes in the coil drive signals. The drive coils are disposed in a common plane and are symmetrically spaced about the central axis, and the phase changes in their drive signals result in a compensating axial force, which may be different in each of the coils to correct tilt. In another or further embodiment, the rotor is freely suspended such that blood washes over one or more surfaces of the rotor, and fluid pressure produces a net restoring force on the rotor to counteract changes in tilt or axial position within the housing. In this case, the driver need only drive rotation of the pump. The drive unit works with a variety of multipole impeller pumps, including ones with magnetic segmented rotors and conventional mechanical support bearings such as ones with a jewel or shaft bearing element. In other embodiments, plural sets of magnets provide passive constraint of radial disturbances and two tilt movements, while axial disturbances are corrected either passively by hydrodynamic surfaces or actively with the driver. The driver unit may include a hand crank assembly, enabling continued operation during power outages.
摘要:
The invention is a disk-shaped screen adapted for removable placement onto one end of a standard-type oil filter. When the screen is placed on the oil filter, it is located in an area bounded by the oil filter's mounting gasket and it overlies the filter's inlet ports. The screen is made of a wire mesh having approximately 1600 openings per square inch. The screen functions to collect larger-sized particles from the oil stream before they enter the interior of the oil filter. By collecting these particles in a readily viewable manner, the screen enables a person to easily determine from the types and size of collected particles if any unusual engine wear has occurred or if the engine has suffered internal damage.