Abstract: A method of improving injectivity of fluid, particularly produced water, in enhanced hydrocarbon recovery is disclosed. The method includes introducing a fracturing fluid into the subterranean formation to create a fracture, and introducing proppant into the fracturing fluid to form a single layer of proppant in the fracture. The fracturing fluid can be formed from produced water. Alternatively, the produced water is introduced after a fracturing fluid, other than the produced water, has been introduced to create a fracture. By reducing the amount of proppant and by using much larger proppant, a larger flow path through the fracture is created, thereby increasing the injectivity of produced water.

Abstract: A technique includes running a string into a well bore and inhibiting formation face failure. The well bore extends at least partially through a non-producing layer and a hydrocarbon formation layer. The inhibiting of the formation face failure includes communicating a proppant into the well bore via the string until a well bore pressure exceeds a first formation stress of the non-producing layer, which causes a fracture to form in the non-producing layer, and communicating the proppant into the fracture to create a barrier layer.

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: Methods of making and using wellbore casing are described, one method comprising providing a plurality of flow-through passages in a portion of a casing while the casing is out of hole; temporarily plugging the flow-through passages with a composition while out of hole; running the casing in hole in a wellbore intersecting a hydrocarbon-bearing formation; and exposing the composition to conditions sufficient to displace the composition from the flow-through passages while in hole. Methods of using the casing may include pumping a stimulation treatment fluid through the casing string and into a formation through the flow-through passages in the first casing joint; plugging the flow-through passages in the first casing section; and exposing a second casing joint of the casing string to conditions sufficient to displace the composition from the flow-through passages in the second casing joint.

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: There is provided an antenna for use in an ultra-wideband device, wherein the antenna is used as an RF radiator and as a heat sink. There is also provided a device for use in an ultra wideband network, the device comprising a component, for example an integrated circuit package, that generates unwanted heat as part of its normal operation, the device further comprising an antenna as described above placed in thermal contact with the component. The antenna may be electrically connected to one or more pins of the component. Alternatively, the antenna may be capacitively connected to the component. There is also provided a heat sink for a wireless communications device, the heat sink being shaped such that it can operate as an antenna for radio frequencies.

Abstract: A method of improving injectivity of fluid, particularly produced water, in enhanced hydrocarbon recovery is disclosed. The method includes introducing a fracturing fluid into the subterranean formation to create a fracture, and introducing proppant into the fracturing fluid to form a single layer of proppant in the fracture. The fracturing fluid can be formed from produced water. Alternatively, the produced water is introduced after a fracturing fluid, other than the produced water, has been introduced to create a fracture. By reducing the amount of proppant and by using much larger proppant, a larger flow path through the fracture is created, thereby increasing the injectivity of produced water.

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: 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 component of interest of an oximeter detector signal is distinguished from an interfering component based on a color difference between the components. The component of interest may be a pulsatile signal component, a baseline signal component such as a respiratory signal, or an artifact signal. The color difference between the component of interest and the interfering component is reflected in corresponding mixing ratios with respect to multiple optical channels of the pulse oximeter. The component of interest is separated from the interfering component by mathematical decomposition using the mixing ratios. In this manner, signal components can be isolated substantially free from frequency dependent filtering.

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 photoplethysmographic sensor and related method for use with a photoplethysmographic instrument such as a pulse oximeter are provided. In accordance with the present invention, the detector output signal from the sensor is digitized prior to communication from the sensor to the instrument and the sensor operates independent of the instrument with respect to controlling the light signal emitters of the sensor. In one embodiment, the digitized detector output signal is communicated to the instrument via a wireless communication link.

Abstract: A support device for an associated cover member includes a hub defining a bore adapted to receive a tip of an associated support pole. A shell projects radially outwardly from the hub. The shell defines an outer surface adapted to support an associated cover member. In use, the device is installed on a tip of a support pole so that an end portion of the tip projects through the support device. The projecting end portion of the pole tip is inserted into a grommet or eyelet of a cover to be supported. The pole is positioned so that the cover is supported on the outer surface of the shell. The device can have an overall frusto-conical shape.

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: 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: A parametric transducer which includes a support member extending along an x-axis and a y-axis and having opposing front and back surfaces. The support member includes an array of parallel ridges extending along the x-axis and spaced apart along the y-axis at predetermined separation distances. The ridges have forward, film contacting faces to support an emitter film in a desired film configuration for emitting parametric output. An electrically sensitive and mechanically responsive (ESMR) film is disposed over the support member with one side of the ESMR film being captured by the film contacting faces, and with arcuate sections aligned with and positioned between the parallel ridges. The film contacting faces mechanically isolate each of the arcuate sections of ESMR film from adjacent arcuate sections.

Abstract: A method for constructing a parametric transducer. The method includes preparing a support member having opposing front and back surfaces, the support member extending along an x-axis and a y-axis. The support member is structured to retain an array of parallel ridges extending along the x-axis and spaced apart along the y-axis at predetermined separation distances. The ridges have forward, film contacting faces to support an emitter film in a desired film configuration for emitting parametric output. An electrically sensitive and mechanically responsive (ESMR) film is applied to the support member with one side of the ESMR film being captured at the film contacting faces, and with arcuate sections disposed between the parallel ridges. The film contacting faces mechanically isolate each of the arcuate sections of ESMR film from adjacent arcuate sections.

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 more 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.