摘要:
The present invention synthesizes a prescribed impedance. The impedance is synthesized by generating a current having a value substantially equal to a voltage divided by a prescribed impedance. Sensing the line voltage and converting that sensed line voltage to its digital equivalent accomplish this first step. The digital line voltage is processed by a factor related to the prescribed impedance to produce an output voltage that has a value substantially equal to the sensed voltage divided by the prescribed impedance. The output voltage controls a voltage to current converter that generates the appropriate current across the points or terminals where the line voltage was measured. Thus, the prescribed impedance is generated across these points or terminals because the line voltage divided by the generated current is substantially equal to the prescribed impedance.
摘要:
A system and circuit is provided for digitally synthesizing the impedance of a transfer function. The impedance of the transfer function is digitally synthesized by generating a current that, when combined with an input voltage, results in the impedance of the transfer function. This is accomplished by sensing the input signal and processing it with a generator or multiplier such that a voltage is produced. The produced voltage controls a current source and creates a current having a value equal to the inverse of the transfer function impedance. The sensed or input voltage divided by the generated current is equal to the impedance of the transfer function. In this manner, many different transfer functions can be digitally synthesized without having to design an alternate circuit.
摘要:
The present invention relates to improved adaptive filtering techniques and architectures. Preferably, this filtering is performed as part of the digital processing that occurs with a digital signal processor. It is a feature of this invention that the adaptive filtering taught herein provides the advantages of both serial and parallel architectures, without the accompanying disadvantages thereof. In particular, an adaptive filter is taught that possesses low pin counts, fast processing times suitable for high-speed applications and reduced numbers of filter elements. In a preferred embodiment, the inputs and outputs of the adaptive filter are supplied to and from the adaptive filter in a serial manner while the processing is performed internally within the adaptive filter in a parallel manner. The parallel processing is preferably effected by a delayed least-means-squares algorithm implemented using a single adder, a single multiplier and a single multiplier-accumulator instead of by numerous such adders, multipliers and multiplier-accumulators.
摘要:
An apparatus, method and system for cannulation of blood vessels. The apparatus comprises a sensor assembly including two linear transducer arrays oriented perpendicular to each other to form a “T” shape to provide ultrasound images of at least one blood vessel in a portion of a patient's body in two perpendicular planes. The sensor assembly may have graphic markings on an exterior surface thereof to facilitate orientation of the sensor assembly on the patient and guidance of a needle toward a desired target vessel during the cannulation procedure. The sensor assembly may also include an associated structure to cooperate with a reference location element to place, align and secure the sensor assembly to the patient's skin at a desired location.
摘要:
An apparatus, method, system, component kit and protective sheath for cannulation of blood vessels are disclosed. The apparatus comprises a sensor assembly to provide ultrasound images of at least one blood vessel in a portion of a patient's body in two perpendicular planes. The sensor assembly may have graphic markings on an exterior surface thereof to facilitate orientation of the sensor assembly on the patient and guidance of a needle towards a desired target vessel during the cannulation procedure. The sensor assembly may also include associated structure to cooperate with a reference location element to place, align and secure the sensor assembly to the patient's skin at a desired location.
摘要:
An apparatus, method and system for cannulation of blood vessels. The apparatus comprises a sensor assembly including two linear transducer arrays oriented perpendicularly to each other to form a “T” shape to provide substantially simultaneous ultrasound images of at least one blood vessel in a portion of a patient's body in two perpendicular planes. The apparatus may also include one or more Doppler transducer elements to transmit and receive one or more Doppler beams at an incident angle beneath one of the transducer arrays and in alignment therewith to determine blood flow direction and velocity within the at least one blood vessel. The sensor assembly may be disposed within an elongated, flexible, protective sheath and secured to a graphically marked cover to facilitate orientation of the sensor assembly on the patient and guidance of a needle towards a desired target vessel during the cannulation procedure. The cover may also include associated structure to cooperate with a reference location element to place, align and secure the sensor assembly to the patient's skin at a desired location.
摘要:
The present invention synthesizes a prescribed impedance. The impedance is synthesized by generating a current having a value substantially equal to a voltage divided by a prescribed impedance. Sensing the line voltage and converting that sensed line voltage to its digital equivalent accomplish this first step. The digital line voltage is processed by a factor related to the prescribed impedance to produce an output voltage that has a value substantially equal to the sensed voltage divided by the prescribed impedance. The output voltage controls a voltage to current converter that generates the appropriate current across the points or terminals where the line voltage was measured. Thus, the prescribed impedance is generated across these points or terminals because the line voltage divided by the generated current is substantially equal to the prescribed impedance.
摘要:
This invention describes a novel method and system that implements wavelet packet trees and inverse wavelet packet trees. A modified Recursive Pyramid Algorithm (RPA) is advanced by this invention. The algorithm uses a filter that changes its size at each given octave of the wavelet packet tree. This filter may also be used in the reconstruction, synthesis, or inverse wavelet packet tree using RPA. The invention reduces the cost of implementing wavelet packet trees by using the same hardware for each octave and thereby offers superior products at attractive prices.
摘要:
The present invention synthesizes a prescribed impedance. The impedance is synthesized by generating a current having a value substantially equal to a voltage divided by a prescribed impedance. Sensing the line voltage and converting that sensed line voltage to its digital equivalent accomplish this first step. The digital line voltage is processed by a factor related to the prescribed impedance to produce an output voltage that has a value substantially equal to the sensed voltage divided by the prescribed impedance. The output voltage controls a voltage to current converter that generates the appropriate current across the points or terminals where the line voltage was measured. Thus, the prescribed impedance is generated across these points or terminals because the line voltage divided by the generated current is substantially equal to the prescribed impedance.