摘要:
MRI/RF compatible leads include at least one conductor, a respective conductor having at least one segment with a multi-layer stacked coil configuration. The lead can be configured so that the lead heats local tissue less than about 10 degrees Celsius (typically about 5 degrees Celsius or less) or does not heat local tissue when a patient is exposed to target RF frequencies at a peak input SAR of at least about 4 W/kg and/or a whole body average SAR of at least about 2 W/kg. Related leads and methods of fabricating leads are also described.
摘要:
An internal combustion engine spark plug provides an overpressure release mechanism to avert engine component damage as a result of hydrostatic lock caused by liquids (typically water) entering the combustion chamber under operating conditions. This spark plug incorporates predictably and adjustably weakened structural zones such that, upon encountering overpressure situations, the central portion of the plug is ejected, generating sufficient flow area to expel gasses and liquids from the combustion chamber and venting the cylinder to the atmosphere. The invention is also useful in the detection and avoidance of damage under conditions of detonation.
摘要:
An internal combustion engine spark plug provides an overpressure release mechanism to avert engine component damage as a result of hydrostatic lock caused by liquids (typically water) entering the combustion chamber under operating conditions. This spark plug incorporates predictably and adjustably weakened structural zones such that, upon encountering overpressure situations, the central portion of the plug is ejected, generating sufficient flow area to expel gasses and liquids from the combustion chamber and venting the cylinder to the atmosphere. The invention is also useful in the detection and avoidance of damage under conditions of detonation.
摘要:
An article comprising a drive cable suitable for high-speed operation in an anatomy having small-radii bends is disclosed. The drive cables disclosed herein include one or more physical adaptations that enable them to be “tuned” to avoid large amplitude vibrations during operation.
摘要:
An article comprising a drive cable suitable for high-speed operation in an anatomy having small-radii bends is disclosed. The drive cables disclosed herein include one or more physical adaptations that enable them to be “tuned” to avoid large amplitude vibrations during operation.
摘要:
An impeller for use in conjunction with a percutaneously-insertable blood pump or other rotatable equipment includes a blade that is segmented into a plurality of overlapping or abutting bladelets. In some embodiments, the bladelets are foldable and one side of each bladelet is concave.
摘要:
An article comprising a drive cable suitable for high-speed operation in an anatomy having small-radii bends is disclosed. The drive cables disclosed herein include one or more physical adaptations that enable them to be “tuned” to avoid large amplitude vibrations during operation.
摘要:
A spark plug for venting excessive engine cylinder pressure may be either pressure or temperature activated. A vent passage is created in a conventional spark plug by drilling an air vent through the housing of a conventional spark plug to a point that experiences cylinder pressures. The air vent is then sealed with a mechanical element of known structural strength and temperature response. Upon the development of excessive engine temperature, cylinder pressure, or both, the sealing element gives way, generating an air passage from the combustion chamber to the atmosphere through which cylinder pressure is vented. By venting excessive pressure, the disastrous effects of detonation, hydrolock, and other deleterious engine conditions may be avoided. Prior to the failure of the seal, the spark plug functions identically to a conventional spark plug.
摘要:
Machine performance, including efficiency, is analyzed in direct frequency domain by measuring the input power to the machine over a range of machine speeds (frequencies, ω). A differentiable mathematical function or model is identified that characterizes the input power vs. speed functional relationship. Successive derivatives of experimental power vs. speed data enable the calculation of coefficients of the mathematical function at a plurality of points (frequencies) in the frequency domain. Performance parameters including machine efficiency, pressure, pressure drag, flow, viscous drag, frictional drag, viscosity and work may be calculated from the coefficients of the mathematical function. One or more desired, optimum or best operating point(s) for machine speed may be defined in terms of the coefficients of the mathematical function or the derived performance parameters.
摘要:
A thrombectomy system incorporates analytical instrumentation to determine the aspirate characteristic (the fluid contents of the thrombectomy catheter) and subsequently selects a thrombectomy operating mode appropriate to the current aspirate characteristic. Aspirate characteristics include: (1) blood, which is slowly aspirated, (2) thrombus which is rapidly aspirated to waste, (3) clot, which is systematically aspirated and (4) clog, which is systematically cleared. A differential viscometer is disclosed for a broad array of applications including thrombectomy, as well as industrial, automotive, environmental and scientific. A variable aperture catheter is disclosed which permits selective aspiration and infusion in either the axial or radial directions.