Abstract: A test and measurement probe device is disclosed. In some implementations, the device may include one or more sensors. In addition, the device may include a plurality of analog signal paths, each analog signal path connected to one of the one or more sensors. The device may include an adjustable gain element within each analog signal path. Moreover, the device may include a combiner to combine the output of each adjustable gain element together to produce a probe output signal. Also, the device may include a digital path including a processor, where the processor is configured to compute a gain value for at least one adjustable gain element.

Abstract: A test and measurement probe for measuring an electrical signal in a device under test (DUT) includes a probe body, a sensor head separate from the probe body, one or more transmission optical fibers to convey an optical measurement signal between the probe body and the sensor head, and a pluggable interface between the probe body and the sensor head. The probe body includes an optical source to produce the optical measurement signal, receiver circuitry to receive the optical measurement signal and convert the optical measurement signal to an electrical measurement signal, and a connector to output the electrical measurement signal to a test and measurement instrument. The sensor head includes one or more sensor head optical fibers configured to convey the optical measurement signal to cause the electrical signal in the DUT to modify a polarization state of the optical measurement signal.

Abstract: A current measurement probe includes two or more magnetic field sensors having a known geometric relationship to allow conversion of signals from the field sensors to a current measurement using the relationship. A test and measurement system includes a current measurement probe including two or more magnetic field sensors having a known geometric relationship to allow conversion of signals from the magnetic field sensors to a current measurement, a test and measurement instrument having at least one port to connect to the current measurement probe, and circuitry to receive the signals from the magnetic field sensors and convert the signals to the current measurement. A method for measuring current includes applying a current measurement probe to a substrate having a conductor carrying current, the current measurement probe having at least two magnetic field sensors having a known geometric relationship, converting signals from the magnetic field sensors to a current measurement.

Abstract: A test and measurement instrument having an integrated analog front end that includes one or more amplifiers, the one or more amplifiers implemented on a high-speed amplifier integrated circuit die, a controlled-impedance signal path between an input and a reference voltage, the controlled-impedance signal path including one or more signal taps and one or more controlled-impedance attenuator stages, the one or more controlled-impedance attenuator stages implemented on the amplifier integrated circuit die, and a switching network structured to selectively couple a signal tap of the controlled-impedance signal path to a respective amplifier of the one or more amplifiers, the switching network implemented on the amplifier integrated circuit die

Abstract: A pumping system is provided. The pumping system includes an output conduit, a first sensor, a second second sensor, a feedforward active controller, and a fluid flow normalizer (FFN). The output conduit is associated with an output of a positive displacement pump. The first sensor is configured to measure a fluid flow characteristic (FFC) within the output conduit. The second sensor is configured to measure a phase of the positive displacement pump. The feedforward active controller is configured to receive information related to the FFC, receive information related to the phase of the positive displacement pump, and determine an FFC variability value. The first fluid flow normalizer (FFN) is configured to at least one of add fluid to the output of the positive displacement pump and remove fluid from the output of the positive displacement pump in response to a signal from the feedforward active controller.

Abstract: A subsea pipeline system has a subsea pipe and a pipeline vibration damper (PVD) attached to the pipe.

Abstract: Systems and methods are disclosed herein that include providing a service life monitoring system that includes a rotatable component and a rotatable measurement interface disposed on the rotatable component, the rotatable measurement interface having at least one torsional strain gauge configured to measure a strain of the rotatable component, a strain monitor controller configured to receive the measured strain of the rotatable component, and a wireless data transmission component configured to wirelessly communicate with the strain monitor controller to receive the measured strain, determine at least one of a power, rotational speed, torque, and service life of the rotatable component in response to receiving the measured strain of the rotatable component as a result of the measured strain of the rotatable component, and control at least one of the power, the rotational speed, and the torque of the rotatable component.

Abstract: Systems and methods are disclosed herein that include providing an active torsion damper control system that includes a rotatable component (206) and a rotatable measurement interface (302) disposed on the rotatable component, the rotatable measurement interface having at least one torsional strain gauge configured to measure a strain of the rotatable component, a torque management (306) computer configured to determine a resonant frequency of the rotatable component and a corrective torque needed to be applied to the rotatable component to excite the resonant frequency as a function of the measured strain, and a correction motor (308) configured to impart the corrective torque on the rotatable component.

Abstract: A subsea pipeline system has a subsea pipe and a pipeline vibration damper (PVD) attached to the pipe.

Abstract: A pumping system includes an output conduit associated with an output of a positive displacement pump, a first sensor configured to measure a fluid flow characteristic (FFC) within the output conduit, a second sensor configured to measure a phase of the positive displacement pump, a feedforward active controller configured to receive information related to the FFC, receive information related to the phase of the positive displacement pump, and determine an FFC variability value, and a first fluid flow normalizer (FFN) configured to at least one of add fluid to the output of the positive displacement pump and remove fluid from the output of the positive displacement pump in response to a signal from the feedforward active controller.

Abstract: Active noise and vibration control (ANVC) systems and methods are provided. The systems and methods include providing sensors configured to detect vibration of a structure and a controller in electrical communication with the sensors. The controller includes a hardware processor and a memory element configured to process the vibration detected by the sensors, generate a force control command signal, and output the force control command signal via an interface. The systems and methods include provisions for at least one circular force generator (CFG) in electrical communication with the controller, the CFG is configured to execute the force control command signal output from the controller and produce a force that substantially cancels the vibration force. In some aspects, one or more CFGs control different vibration frequencies causing unwanted vibrations or acoustical tones. In some aspects, one or more CFG's control unwanted vibrations during some conditions and noise during other conditions.

Abstract: An initialization module in a pulse oximeter accommodates a variety of different probes and a variety of operating parameters as well as providing for interrogation of various probe circuits for detection of probe faults. Probe fault detection for the red and infrared LED circuits of the probe is implemented using an adaptive algorithm that is dependent on the drive settings or signals applied to the LED circuits. A configurable circuit is used to provide multiple initialization values relating to a calibration circuit of the probe for improved fault detection. Additionally, potential faults with respect to the photodetector circuit of a probe are identified based on monitoring drawn by an output by the photodetector.

Abstract: A photoplethysmographic system and method is provided for filtering a photoplethysmographic (pleth) signal to reduce the effects of noise in the signal. The system and method utilize a combination of frequency, time and/or magnitude information, to identify and separate transient signal components within a pleth signal from repeating signal components within the pleth signal. Typically, signal components of interest repeat over a period that corresponds with a patient's heartbeat. Such periodically repeating signals may be identified as stationary signals/objects within a frequency and time-based analysis. In contrast, motion artifacts or other sources of noise are often isolated (i.e., non-repeating) transient events and may be identified as non-stationary objects in a frequency and time-based analysis. Data associated with identified transient events may be filtered from or otherwise removed from a given signal. In this regard, a pleth signal may be cleansed prior to its use for, e.g.

Abstract: A detector signal in a pulse oximeter is prefiltered, prior to processing so as to determine a physiological parameter value, so as to reduce the effects of artifact in the signal. An exemplary prefilter multiplies signal amplitude values by a quantitude that is inversely proportional to a substantially current amplitude so as to reduce the amplitude of large amplitude sections typically associated with artifact. In one implementation, the quantity is a ratio of an amplitude associated with a clean section of the signal by some exponential factor of a substantially current amplitude. In this manner, artifact affected portions of the signal are deemphasized in subsequent analyses.

Abstract: A method for use in operating a signal attenuation measurement device used to obtain a physiological parameter of a patient and an apparatus for use in determining at least one physiological parameter relating to a patient from at least first and second signals transmitted to a patient tissue site and attenuated thereby are provided. In accordance with the method and apparatus of the present invention, the first and second signals are multiplexed using frequency orthogonal code division multiplexed excitation waveforms. This allows for both relatively good source separation of the signals and whitening of external noise.

Abstract: An oversampling pulse oximeter includes an analog to digital converter with a sampling rate sufficient to take multiple samples per source cycle. In one embodiment, a pulse oximeter (100) includes two or more light sources (102) driven by light source drives (104) in response to drive signals from a digital signal processing unit (116). The source drives (104) may drive the sources (102) to produce a frequency division multiplex signal. The optical signals transmitted by the light sources (102) are transmitted through a patient's appendage (103) and impinge on a detector (106). The detector (106) provides an analog current signal representative of the received optical signals. An amplifier circuit (110) converts the analog current signal to an analog voltage signal in addition to performing a number of other functions. The amplifier circuit (110) outputs an analog voltage signal which is representative of the optical signals from the sources (102).

Abstract: An oximeter has an op-amp with a first input, a second input, and an output, the first input being directly connected to a reference voltage. A switch has an input connected to the output of the op-amp, and has a plurality of switch outputs. A transistor has a control input connected to one of the plurality of outputs, and has a current source terminal and a supply terminal. A diode is connected to the current source terminal of the transistor. The supply terminal of the transistor is connected both to the second input of the op-amp and to a second one of the plurality of switch outputs. The switch is thereby in a feedback loop of the op-amp, effecting a feedback-controlled switch for switching the diode on and off.

Abstract: A system and method of reducing cross talk in pulse oximetry signals that are attenuated by a patient tissue site are provided. In one embodiment, Red and IR LEDs of a pulse oximeter are separately excited (1010) and the respective Red and IR data vectors output by the detector are measured (1020). The Red and IR data vectors are normalized (1030). Red to IR and IR to Red cross talk vectors are computed (1040). Red and IR demodulation vectors are obtained by subtracting (1050) the respective Red and IR cross talk vectors from the respective normalized Red and IR data vectors. The demodulation vectors are normalized (1060), scaled (1070), and the magnitudes of the Red and IR signal components are obtained by computing (1080) the dot product of the composite signal data vector with the normalized and scaled Red demodulation and IR demodulation vectors, respectively.

Abstract: An oversampling pulse oximeter includes an analog to digital converter with a sampling rate sufficient to take multiple samples per source cycle. In one embodiment, a pulse oximeter (100) includes two mor more light sources (102) driven by light source drives (104) in response to drive signals from a digital signal processing unit (116). The source drives (104) may drive the sources (102) to produce a frequency division multiplex signal. The optical signals transmitted by the light sources (102) are transmitted through a patient's appendage (103) and impinge on a detector (106). The detector (106) provides an analog current signal representative of the received optical signals. An amplifier circuit (110) converts the analog current signal to an analog voltage signal in addition to performing a number of other functions. The amplifier circuit (110) outputs an analog voltage signal which is representative of the optical signals from the sources (102).

Abstract: A method of producing a diode drive current in an oximeter includes sensing at least a part of a current passing through the diode and converting the sensed current to a sensed voltage, inputting the sensed voltage to a feedback amplifier for stabilizing the current passing through the diode, and eliminating an offset voltage across inputs of the feedback amplifier. A pulse oximeter includes a diode for emitting light flashes, a feedback amplifier having inputs, a feedback capacitor, and an output, the feedback amplifier stabilizing a current passing through the diode, a nulling amplifier having inputs, a nulling capacitor, and an output, the nulling amplifier charging and discharging the feedback capacitor until the inputs of the feedback amplifier are at a same voltage. The operation may include synchronizing an elimination of input offset voltages of the feedback and nulling amplifiers with on or off state of diode current.