3202 results about "Preamplifier" patented technology

An adapter allows the interconnection of a sensor originating from one manufacturer to be coupled with conventionally incompatible monitors originating from other manufacturers to form a properly functioning pulse oximetry system. The adapter matches a sensor driver in a monitor to the current requirements and light source configuration of a sensor. The adapter also matches a sensor's light detector signal level to the dynamic range requirements of a monitor preamplifier. Further, the adapter provides compatible sensor calibration, sensor type and security information to a monitor. The adapter may have a self-contained power source or it may derive power from the monitor, allowing both passive and active adapter components. The adapter is particular suited as an adapter cable, replacing a conventional patient cable or sensor cable as the interconnection between a sensor to a monitor in a pulse oximetry system.

A speaker system for a musical instrument that detects the displacement of a voice coil of a speaker and provides feedback processing. The speaker system has a preamp that alters the frequency characteristics of the an electrical signal that has been input to an input terminal, and a power amplifier that amplifies the electrical signal. A speaker is driven by the power amplifier and a feedback unit detects the displacement of the speaker and provides a feedback signal to the power amplifier. The power amplifier amplifies the electrical signal in conformance with the output of the preamp and the feedback signal.

A switchable bandwidth optical receiver is implemented in a front-end of the receiver in at least one of three ways. A switchable impedance may be provided at the input to a preamplifier of the front end, the preamplifier of the front-end may have a switchable impedance therein, and/or a switchable filter may be provided at an output of the preamplifier.

A modular ultrafast pulse laser system is constructed of individually pre-tested components manufactured as modules. The individual modules include an oscillator, pre-amplifier and power amplifier stages, a non-linear amplifier, and a stretcher and compressor. The individual modules can typically be connected by means of simple fiber splices.

An intraoperative probe system for preferentially detecting beta radiation over gamma radiation emitted from a radiopharmaceutical is described. In one embodiment, the probe system of the present invention is a probe having an ion-implanted silicon charged-particle detector for generating an electrical signal in response to received beta particles. In such an embodiment, a preamplifier may be located in close proximity to the detector filters and amplifies the electrical signal. Furthermore, a wire may be used to couple the probe to a processing unit for amplifying and filtering the electrical signal, and a counter may be utilized to analyze the resulting electrical signal to determine the number of beta particles being received by the detector. Alternatively, the wire can be replaced with an infrared or radio transmitter and receiver for wireless operation of the probe.

A combined PET/MRI scanner generally includes a magnet for producing a magnetic field suitable for magnetic resonance imaging, a radiofrequency (RF) coil disposed within the magnetic field produced by the magnet and a ring tomograph disposed within the magnetic field produced by the magnet. The ring tomograph includes a scintillator layer for outputting at least one photon in response to an annihilation event, a detection array coupled to the scintillator layer for detecting the at least one photon outputted by the scintillator layer and for outputting a detection signal in response to the detected photon and a front-end electronic array coupled to the detection array for receiving the detection signal, wherein the front-end array has a preamplifier and a shaper network for conditioning the detection signal.

A method of servo writing a disk for use in a disk drive is disclosed by writing discontinuous spiral tracks on the disk to protect against overheating the head and/or preamp circuitry. A write clock is synchronized to the rotation of the disk, and a plurality of discontinuous spiral tracks are written on the disk. Each discontinuous spiral track is written at a predetermined circular location determined from the write clock, and each discontinuous spiral track comprises a plurality of segments separated by gaps. Each segment comprises a high frequency signal interrupted at a predetermined interval by a sync mark.

The present invention relates to a preamplifier suitable for use with Electret Condenser Microphones such as used within telecommunication equipment. More particularly the invention relates to a preamplifier specially suited for the demands to such a preamplifier within telecommunication equipment: low input capacitance, gain and a combined terminal for output and supply voltage, thus making the preamplifier suitable for two terminal microphone assemblies. These features are obtained with a two stage amplifier with a first stage optimised for low input capacitance and the second stage being able to provide gain. The preamplifier may be implemented using an ASIC, thus making the preamplifier suitable for applications with very limited space available, such as for integration within microphone assemblies.

A pre-amplifier (column region unit) of a solid-state imaging device includes a pixel-signal controller. The pixel-signal controller, for each vertical signal line, detects the level of each pixel signal independently by a pixel-signal detector on the output side of a pixel-signal amplifier, and sets a gain independently to the pixel-signal amplifier according to the level of the signal. At a subsequent stage of the solid-state imaging device, an analog-to-digital (A/D) converter and a signal extending unit are provided. The A/D converter digitizes a pixel signal, and the digitized pixel signal is corrected by a gain set to the pixel-signal amplifier with reference to a classification signal from the pixel-signal detector, so that the dynamic range of signals of one screen is extended.

A high-gain and low-noise low noise amplifier (LNA) includes a differential amplifier, a pre-amplifier and an impedance matching network. The differential amplifier includes a first input end and a second input end coupled to a grounded impedance. The pre-amplifier includes an input end and an output end. The impedance matching network is coupled between the first input end of the differential amplifier and the output end of the pre-amplifier for matching an input impedance of the differential amplifier with an output impedance of the pre-amplifier. The present invention provides a LNA structure with low noise, high gain and easy design.

A method for increasing the throughput, or the precision, or both the precision and the throughput, of a flow cytometer, or of a hematology analyzer employing a flow cytometer, by utilizing the technique of laser rastering. Laser rastering involves sweeping a laser beam across a flowing sample stream in a hematology analyzer. An apparatus suitable for carrying out the method of this invention comprises an optical module comprising a source of light, a scanning device, a lens or system of lenses, a flow cell, detectors, and filters; and an electronic module comprising preamplifiers, analog signal conditioning elements, analog-to-digital converters, field-programmable gate arrays, digital signal processing elements, and data storage elements.

The present invention relates to an audio amplification circuit comprising a first preamplifier for receipt of an audio input signal and a second preamplifier comprising a first differential input for receipt of an attenuated audio input signal. The attenuated audio input signal is generated by an attenuator coupled to the audio input signal. A non-linear element is coupled to a first input of the first preamplifier thereby distorting the audio input signal at the first input at large signal levels. A distortion compensation network is adapted to supply a distortion compensation signal from the first input of the first preamplifier to a second differential input of the second preamplifier such that distortion in the output signal of the second preamplifier is cancelled or attenuated. The invention further relates to a corresponding method of compensating an audio amplification circuit for distortion induced by a non-linear element.

A Solid State Power Amplifier (SSPA) for powering a single element of a multi-element antenna, the SSPA comprising:

an RF amplifier, having a signal amplifying path that includes preamplifier, driver amplifier and a power output stage;

an Electronic Power Conditioner (EPC) for providing a variable value of DC voltage for powering the power output stage of the RF amplifier;

a control ASIC for receiving an input power signal of the RF amplifier for providing a voltage control signal to the EPC to determine the value of the DC voltage, the control ASIC addressing an EEPROM holding a collection of control words that define output values of a control output signal for varying values of said input power, such that the value of the DC voltage to the power output stage is varied so as to control the gain compression of the RF amplifier for varying values of input power in order to maintain constant amplifier linearity.

A reliable, safe, accurate, low noise, inexpensive, portable amplifier circuit is adapted to accurately amplify both AC and DC neural response signals. A patient or subject is electrically connected to a multi-channel system for electrically measuring the patient's AC and DC neural response signals at a plurality of locations using electrodes connected through a multi-electrode cable. The neural response signals are input to a digital DC amplifier to filter, amplify and digitize the neural response signals. Digitized neural response signals are converted to optical signals and transmitted via a fiber optic cable to an interface that is preferably connected to a patient stimulus generator (e.g., a Ganzfeld stimulator or pattern stimulator for multi-focal ERG). The system also includes a stand-alone computer such as an IBM® compatible Personal Computer (PC) for two-way communication with the interface via a standard data interface cable (e.g., a USB cable). In the preferred embodiment, a digital DC amplifier is worn by the patient and receives each neural response signal at a two-conductor balanced input; a surge suppression circuit limits excessive voltage transients at the input. The neural response signal is next input to a balanced buffer amplifier stage for impedance matching and the buffered neural response signal is then input to a balanced, adjustable pre-amplifier stage having an adjustable gain which can be varied (e.g., from ×1 to ×64). The buffered, amplified neural response signal is then digitized for storage in a memory and transmission to a fiber-optic digital transmission circuit. An adjustable impedance element generates a DC offset compensation signal used to control a D.C. offset compensation amplifier to generate an offset control signal for input to gain-adjustable pre-amplifier stage, to maximize sensitivity and usable dynamic range.

Methods and systems for receiving different types of signal formats from different ultrasound transducers are provided. A base unit of an ultrasound system includes a connector and receiver circuit for connecting with one of multiple different types of transducers. For example, a conventional transducer providing analog information associated with a single element on one receive channel is connected with the connector and receiver circuit. Alternatively, a transducer outputting time division multiplex or other multiplex information representing multiple transducer elements is connected with the connector and receiver circuit. The receiver circuit processes the received information differently depending on the data format. For example, the preamplifier impedance or gain is different for single element signals versus time division multiplex signals. As another example, a low pass filter bandwidth is larger for time division multiplex signals than for signals representing a single element. Receive circuits with an analog-to-digital converter positioned prior to a digital demultiplexer are also included for use with multiplexed data formats. Time division multiplex or other multiplex signals from a transducer array are converted to a digital format prior to demultiplexing. Methods and systems for adapting multiplexing or processing of multiplexed signals are also provided. A test signal or ultrasound signals are transmitted from a transducer to the receiver circuit and analyzed. The multiplexer of the transducer is synchronized with an analog digital converter with selectable delays responsive to the analysis. Coefficients or other filter characteristics of a digital equalizer are selected as a function of the analysis.

A method and apparatus for processing signals output from an array of X-ray radiation detectors which receive X-ray radiation emanating from an object irradiated by a source beam of X-ray radiation, to thereby produce an visual image of internal object features, utilizes repetitive sampling P times and digital accumulation of signals output from each detector to increase signal-to-noise ratio of the images by the factor 1/✓P. In a basic embodiment, each of the N detectors in a linear detector array is sampled P times. In another embodiment, artifacts resulting from decay of detector pre-amplifier output voltages on capacitors of low-pass filter circuits, referred to as pseudo-integrators, are reduced by sequentially sampling and accumulating each of N detector amplifier output voltages P times in turn, and repeating the sampling and accumulating sequence Q times, thereby reducing variations in the P×Q accumulated values between the first and last detector channels of an N detector array.

Method and apparatus are presented for electrically coupling a slider to ground. In one embodiment, a bonding pad is provided on a side of the slider body separate from the bonding pad(s) used for read/write signals. This separate bonding pad is electrically coupled within the slider body to components that are to be coupled to ground. A separate conductor provided on the suspension (e.g., a trace, a flex circuit, etc.) may be electrically coupled to the separate bonding pad via gold ball bonding. The conductor is also coupled to ground in the hard-disk drive device (e.g., via the preamplifier). The use of the separated bonding pad and trace may negate the need to use a conductive adhesive to electrically ground the slider via its attachment to the tongue of a slider.

A cryogenic inertial Micro-Electro-Mechanical System (MEMS) device is provided. The device may include a vibratory gyroscope operable to sense a rotational acceleration. The device may also include a pre-amplifier co-located in a close proximity to the vibratory gyroscope. The device may be operated at substantially low temperatures, such as cryogenic temperatures, to reduce electrical noise and improve stability of outputs of the system.

Apparatus for assessing the electrical properties of patient-electrode interfaces has a carrier signal source injecting two carrier signals comprising an AC signal with a DC offset to the electrodes. The carrier signals are out of phase. The outputs from the electrodes are formed into electrocardiographic lead signals in a pre-amplifier circuit. Signal processing circuit is coupled to the pre-amplifier circuit and provides a first signal comprising the AC carrier signal contained in an ECG lead signal and a second signal containing a DC offset signal. The first and second signals are provided to a microprocessor to obtain an output indicative of the electrical properties of electrode interfaces for the ECG lead signal.

An apparatus and method for receiving high-speed signals having a wide common-mode range with low input-to-output latency. In one embodiment, the receiver includes an integrator to accumulate charge in accordance with an input signal during an integration time interval to produce an output voltage. A sense amplifier samples and converts the output voltage of the integrator to a logic signal; and a latch stores the logic signal. In an alternate embodiment, a preamplifier conditions the input signal prior to being integrated. In another embodiment using multiple receivers, circuitry is added to the receiver to compensate for timing errors associated with the distribution of the timing signals. In yet another embodiment, the integrator is coupled to an equalization circuit that compensates for intersymbol interference. In another embodiment, another circuit compensates for accumulated voltage offset errors in the integrator.

A removable and portable single pickup unit for stringed instruments such as guitars, and the like. The unit can be mounted inside of a sound hole of an acoustic guitar without damaging the guitar. The unit can combine inputs from three different pickups(such as a magnetic sensor, vibratory transducer, and a microphone) into a single small housing. The unit can include a pre-amplifier and circuitry within the unit along with three rotatable rheostat type control knobs for each of the pickups, and an overall volume control knob that are easily reachable to the user's fingers while the fingers are on the strings. An output cable connects the unit to a single external amplifier or three individual amplifiers for each of the three different pickups.