摘要:
The invention relates to substrates of semi-insulating silicon carbide used for semiconductor devices and a method for making the same. The substrates have a resistivity above 106 Ohm-cm, and preferably above 108 Ohm-cm, and most preferably above 109 Ohm-cm, and a capacitance below 5 pF/mm2 and preferably below 1 pF/mm2. The electrical properties of the substrates are controlled by a small amount of added deep level impurity, large enough in concentration to dominate the electrical behavior, but small enough to avoid structural defects. The substrates have concentrations of unintentional background impurities, including shallow donors and acceptors, purposely reduced to below 5·1016 cm−3, and preferably to below 1·1016 cm−3, and the concentration of deep level impurity is higher, and preferably at least two times higher, than the difference between the concentrations of shallow acceptors and shallow donors. The deep level impurity comprises one of selected metals from the periodic groups IB, IIB, IIIB, IVB, VB, VIB, VIIB and VIIIB. Vanadium is a preferred deep level element. In addition to controlling the resistivity and capacitance, a further advantage of the invention is an increase in electrical uniformity over the entire crystal and reduction in the density of crystal defects.
摘要:
An implantable medical device having an optical sensor selects the function of modular opto-electronic assemblies included in the optical sensor. Each assembly is provided with at least one light emitting device and at least one light detecting device. A device controller coupled to the optical sensor controls the function of each the assemblies. The controller executes a sensor performance test and selects at least one of the plurality of assemblies to operate as a light emitting assembly in response to a result of the performance test. The controller selects at least one other of the plurality of optical sensor assemblies to operate as a light detecting assembly in response to a result of the performance test
摘要:
Mounting system for substantially increasing the wear life of a screen panel which is adapted to be vibrated, utilizes elastomeric material, such as urethane, to isolate the vibrating mechanism from direct contact with the screen panel. An elastomeric wear strip is bonded to screen wires on the underside of the screen panel. A recessed channel formed in the bottom of the wear strip is adapted to engage an upper contact surface of a rigid vibrating bar member, while the side edges of the channel extend downwardly over the sides of the rigid vibrating bar member to prevent abrasive material which has passed through slots in the screen panel from entering the contact area between the recessed channel and the upper contact surface. The upper contact surface of the vibrating bar member is preferably covered with elastomeric material and crowned so as to cause the screen panel to become curved when its side edges are forced down by a pair of hold-down bars. Contact between the hold-down bars and the screen panel and contact between the ends of the vibrating bar member and the side walls of the screen box assembly is preferably made through layers of elastomeric material. The hold-down bars preferably include angled wedge-shaped portions on their upper surfaces which cooperate with angled brackets on the side walls of the screen box assembly to force the side edges of the screen panel downwardly. Flow diverter strips are provided at the ends of the screen panel to prevent material which has flowed through the screen slots from leaving the screen box.
摘要:
A trowel for spreading glue on floor surfaces having a flat plate to which is attached a handle, above and back of which is a grip pressure release assembly.
摘要:
Various fixation techniques for implantable medical device (IMDs) are described. In one example, an assembly comprises an IMD; and a set of active fixation tines attached to the IMD. The active fixation tines in the set are deployable from a spring-loaded position in which distal ends of the active fixation tines point away from the IMD to a hooked position in which the active fixation tines bend back towards the IMD. The active fixation tines are configured to secure the IMD to a patient tissue when deployed while the distal ends of the active fixation tines are positioned adjacent to the patient tissue.
摘要:
Various fixation techniques for implantable medical device (IMDs) are described. In one example, an assembly comprises an IMD; and a set of active fixation tines attached to the IMD. The active fixation tines in the set are deployable from a spring-loaded position in which distal ends of the active fixation tines point away from the IMD to a hooked position in which the active fixation tines bend back towards the IMD. The active fixation tines are configured to secure the IMD to a patient tissue when deployed while the distal ends of the active fixation tines are positioned adjacent to the patient tissue.
摘要:
An optical sensor for a medical device includes a fixed lens spacing between emit and receive modules to achieve target sensor sensitivity, while varying other sensor parameters in order to increase signal amplitude without increasing power demand. An optical sensor connected to a housing of a medical device includes a circuit board, an opto-electronic component, a wall, a lens, and a ferrule. The circuit board is arranged within the housing. The opto-electronic component is mounted on a surface of the circuit board. The wall protrudes from the surface of the circuit board and surrounds the opto-electronic component. The lens is offset from the surface of the circuit board. The ferrule is connected to the housing, the lens and the wall. An inner surface of the wall mates with an outer surface of the ferrule.
摘要:
Various fixation techniques for implantable medical device (IMDs) are described. In one example, an assembly comprises an IMD; and a set of active fixation tines attached to the IMD. The active fixation tines in the set are deployable from a spring-loaded position in which distal ends of the active fixation tines point away from the IMD to a hooked position in which the active fixation tines bend back towards the IMD. The active fixation tines are configured to secure the IMD to a patient tissue when deployed while the distal ends of the active fixation tines are positioned adjacent to the patient tissue.