Abstract: A physiological sensing stethoscope suitable for use in high-noise environments is disclosed. The stethoscope is designed to be substantially matched to the mechanical impedance of monitored physiological activity and substantially mismatched to the mechanical impedance of air-coupled acoustic activity. One embodiment of the stethoscope utilizes a passive acoustic system. Another embodiment utilizes an active Doppler system. The passive and active systems can be combined in one stethoscope enabling switching from a passive mode to an active mode suitable for use in very high-noise environments. The stethoscope is suitable for use in environments having an ambient background noise of 100 dBA and higher. The passive includes a head having a housing, a flexural disc mounted with the housing, and an electromechanical stack positioned between the housing and the flexural disc in contact with the skin of a patient. The active system detects Doppler shifts using a high-frequency transmitter and receiver.

Abstract: A physiological sensing stethoscope suitable for use in high-noise environments is disclosed. The stethoscope is designed to be substantially matched to the mechanical impedance of monitored physiological activity and substantially mismatched to the mechanical impedance of air-coupled acoustic activity. One embodiment of the stethoscope utilizes a passive acoustic system. Another embodiment utilizes an active Doppler system. The passive and active systems can be combined in one stethoscope enabling switching from a passive mode to an active mode suitable for use in very high-noise environments. The stethoscope is suitable for use in environments having an ambient background noise of 100 dBA and higher. The passive includes a head having a housing, a flexural disc mounted with the housing, and an electromechanical stack positioned between the housing and the flexural disc in contact with the skin of a patient. The active system detects Doppler shifts using a high-frequency transmitter and receiver.

Abstract: A physiological sensing stethoscope suitable for use in high-noise environments is disclosed. The stethoscope is designed to be substantially matched to the mechanical impedance of monitored physiological activity and substantially mismatched to the mechanical impedance of air-coupled acoustic activity. One embodiment of the stethoscope utilizes a passive acoustic system. Another embodiment utilizes an active Doppler system. The passive and active systems can be combined in one stethoscope enabling switching from a passive mode to an active mode suitable for use in very high-noise environments. The stethoscope is suitable for use in environments having an ambient background noise of 100 dBA and higher. The passive includes a head having a housing, a flexural disc mounted with the housing, and an electromechanical stack positioned between the housing and the flexural disc in contact with the skin of a patient. The active system detects Doppler shifts using a high-frequency transmitter and receiver.

Abstract: A ceramic dielectric composition suitable for preparing capacitors for use in high-temperature service conditions is disclosed. The ceramic material and capacitors made from it exhibit unique and heretofore unrealizable properties including low variation in capacitance with voltage up to high fields, low variation in capacitance with temperature over a broad temperature range, retained high permittivity at temperatures up to 200° C. and beyond, low loss, low field-induced strain and adequate capacitance to retain performance at very low service temperatures. The material is based on sodium bismuth titanate (NBT) with selected additions of substituents and dopants to broaden and flatten its dielectric response, lower loss, lower strain, lower voltage coefficient and increase resistivity.

Abstract: A ceramic dielectric composition suitable for preparing capacitors for use in high-temperature service conditions is disclosed. The ceramic material and capacitors made from it exhibit unique and heretofore unrealizable properties including low variation in capacitance with voltage up to high fields, low variation in capacitance with temperature over a broad temperature range, retained high permittivity at temperatures up to 200° C. and beyond, low loss, low field-induced strain and adequate capacitance to retain performance at very low service temperatures. The material is based on sodium bismuth titanate (NBT) with selected additions of substituents and dopants to broaden and flatten its dielectric response, lower loss, lower strain, lower voltage coefficient and increase resistivity.

Abstract: A non-invasive brain assessment monitor is disclosed. An embodiment of the monitor includes a head-mounted brain sensor which passively senses acoustic signals generated from pulsing blood flow through a patient's brain. A reference sensor may be mounted at another location on the patient's body to sense an arterial pulse, and the signals from the brain sensor and reference sensor may be compared. Another embodiment includes transmitters which generate acoustic signals in the brain which are also detected by the brain sensor. The brain assessment monitor may be used to detect conditions such as head trauma, stroke and hemorrhage.

Abstract: A compact hybrid actuator has a fluid pump (20) arranged to supply fluid to an actuator (44). The pump has at least one electrically-powered solid-state pump driver (21) provided with a displacement element (22). The position of this displacement element modulates the volume of a fluid chamber (23). A driven valve (24) is operatively arranged to control the flows of fluid with respect to the pump chamber, and has one member (29) movable relative to a body (28) to modulate the opening of ports (25, 26) so as to form at least one three-way valve. A valve driver (31) is operatively arranged to operate the driven valve. Electrical power is provided to each valve and to the valve driver so as to operate these various elements in synchronism with one another. The improved pump driver and driven valve may be operated at frequencies in excess of 1 kHz.

Abstract: A compact hybrid actuator has a fluid pump (20) arranged to supply fluid to an actuator (44). The pump has at least one electrically-powered solid-state pump driver (21) provided with a displacement element (22). The position of this displacement element modulates the volume of a fluid chamber (23). A driven valve (24) is operatively arranged to control the flows of fluid with respect to the pump chamber, and has one member (29) movable relative to a body (28) to modulate the opening of ports (25, 26) so as to form at least one three-way valve. A valve driver (31) is operatively arranged to operate the driven valve. Electrical power is provided to each valve and to the valve driver so as to operate these various elements in synchronism with one another. The improved pump driver and driven valve may be operated at frequencies in excess of 1 kHz.

Abstract: A non-invasive brain assessment monitor is disclosed. An embodiment of the monitor includes a head-mounted brain sensor which passively senses acoustic signals generated from pulsing blood flow through a patient's brain. A reference sensor may be mounted at another location on the patient's body to sense an arterial pulse, and the signals from the brain sensor and reference sensor may be compared. Another embodiment includes transmitters which generate acoustic signals in the brain which are also detected by the brain sensor. The brain assessment monitor may be used to detect conditions such as head trauma, stroke and hemorrhage.

Abstract: The present invention relates to a non-invasive device for measuring physiological processes. More particularly, it concerns a device that can be applied externally to the body of an animal or human to detect and quantify displacement, force, motion, vibration and acoustic effects resulting from internal biological functions. Specifically, an inexpensive device is disclosed that is compact, light, portable and comfortable, and operates satisfactorily even with imprecise location on the body, ambient noise, motion and light.

Abstract: A non-invasive apparatus and method are disclosed for measuring intracranial pressure. The intracranial measurement system transmits acoustic signals through a cranium and provides an indication of intracranial pressure based on the received acoustic signals after interaction with the brain. Properties such as acoustic transmission impedance, resonant frequency, resonance characteristics, velocity of sound and the like may be measured and correlated with intracranial pressure. The acoustic signals have typical frequencies of less than 100 kHz, for example, in the audible and sub-audible frequency ranges. The intensity of the transmitted acoustic signals used to determine intracranial pressure is relatively low, resulting in little or no health risks during short term or long term monitoring.

Abstract: Aluminum cells may be produced having cathode surfaces which are wetted by aluminum, said surfaces comprising Refractory Hard Materials in a non-graphitized carbon matrix. Such cells may utilize inclined or drained cathodes as well as non-consumable anodes.

Abstract: Aluminum cells may be produced having cathode surfaces which are wetted by aluminum, said surfaces comprising Refractory Hard Materials in a non-graphitized carbon matrix. Such cells may utilize inclined or drained cathodes as well as non-consumable anodes.

Abstract: This invention relates to an improved coating composition for application to aluminum cell cathodes, wherein said composition comprises a Refractory Hard Material, and a thermosetting resinous binder system.The resinous binder system is characterized by a char yield greater than 25 percent, while the coating composition exhibits expansion characteristics such as to adhere to a cathode block at temperatures up to and including those normally encountered in the operation of an aluminum cell. The ablation rate of the carbon system utilized is essentially equal to the combined wear and dissolution rate of the Refractory Hard Material in an aluminum cell environment.

Abstract: This invention relates to a method for the application of a coating composition containing Refractory Hard Material to a cathode substrate to prepare an aluminum wettable cathode surface.A mixture of Refractory Hard Material and carbon system is applied to a cathode substrate, cured and carbonized to a non-graphitized carbon matrix containing Refractory Hard Material, characterized by strong bonding of said matrix to said substrate and an ablation rate of said carbon matrix similar to the combined rate of wear and dissolution of the Refractory Hard Material.

Abstract: A method of cation reduction by anode-assisted electrolysis comprises electrolyzing cations at a cathode of a cell in which the anolyte contains ferrous ion as a reducing agent, with relative motion between the anode and the anolyte such as to promote contact of the anode with ferrous ion despite their mutual electrostatic repulsion, wherein the concentration of the ferrous ion is from 0.5 to 10 g/l. The relative motion between the anode and the anolyte can take the form of air-sparging. The method can be used to produce copper metal from copper solution. While static relationship is maintained between the cathode and the catholyte, the anolyte being in free communication with the catholyte.