Abstract: An optoacoustic system and method for providing enhanced laser safety includes a laser light source, a control and processing system, a laser override, and an array of optoacoustic transducers. The laser light source is capable of generating a laser light pulse upon receiving a laser light source trigger. The control and processing system is configured to generate a laser light source trigger, to receive and process ultrasound data, and to control operation of the optoacoustic system. The control and processing system determines whether received ultrasound data reflects acoustic coupling between the transducer array and the volume. The laser override is configured to automatically prevent the generation of a laser light pulse if received ultrasound data does not reflect acoustic coupling between the optoacoustic transducer array and the volume.

Abstract: An optoacoustic imaging system includes an ultrasound transducer array, first and second light sources and a switching power supply that generates power for the light sources. The switching power supply includes an input for impeding its switching operation. A data acquisition unit samples the ultrasound transducer array for a first predetermined period of time after a pulse of light from the first light source and for a second predetermined period of time after a pulse of light from the second light source and stores the sampled data. A master processor utilizes the input to impede operation of the switching operation of the switching power supply during the first predetermined period of time after a pulse of light from the first light source, and during the second predetermined period of time after a pulse of light from the second light source.

Abstract: An optoacoustic system and method for providing enhanced laser safety includes a laser light source, a control and processing system, a laser override, and an array of optoacoustic transducers. The laser light source is capable of generating a laser light pulse upon receiving a laser light source trigger. The control and processing system is configured to generate a laser light source trigger, to receive and process ultrasound data, and to control operation of the optoacoustic system. The control and processing system determines whether received ultrasound data reflects acoustic coupling between the transducer array and the volume. The laser override is configured to automatically prevent the generation of a laser light pulse if received ultrasound data does not reflect acoustic coupling between the optoacoustic transducer array and the volume.

Abstract: Fail-safe methods for deactivating the pulsed neutron generator (PNG) of a logging tool are described herein, as are logging tools configured to execute the fail-safe methods. The fail-safe methods deactivate the PNG if the logging tool is disposed in air outside of a borehole. Measurements taken using one or more gamma ray detectors of the logging tool are used to calculate a value for a parameter that is indicative of the tool being disposed in an air environment. Examples of such parameters include ratios of capture gamma rays and burst gamma rays. The disclosed methods operate without reference to sensors and/or control from outside the tool. The methods do not inadvertently deactivate the tool when it encounters an air-filled borehole.

Abstract: Methods, tools, and systems for determining porosity in an earth formation are disclosed. Neutrons are emitted into the formation to induce inelastic scattering gamma rays and thermal capture gamma rays in the formation. The induced gamma rays are detected at a proximal gamma detector and a far gamma detector, which are spaced at different axial distances from the neutron source. A measured proximal-to-far inelastic ratio (a ratio of inelastic scattering gammas detected at the proximal and far detector) and a proximal-to-far thermal capture ratio (a ratio of thermal capture gammas detected at the proximal and far detector) are determined and used to calculate the formation porosity. Techniques are disclosed for removing borehole and casing configuration effects from the measured proximal-to-far thermal capture ratio, leaving only porosity dependence.

Abstract: Methods, tools, and systems for determining the lithium concentration of a formation traversed by a wellbore using pulsed neutron logging are described. Since determining lithium directly using pulsed neutron logging is problematic, this disclosure provides ways of determining lithium concentration indirectly using models that relate lithium concentration with concentrations of other elements that are predicted to be associated with lithium.

Abstract: A serialized probe component for an optoacoustic device has a unique identifier associated therewith and includes, in an embodiment, an operative connection between a read-write memory and the optoacoustic device. Software adapted to generate and store logs in a read-write memory is executed on the optoacoustic device and stores logs concerning utilization of the serialized probe component on the read-write memory. A method for logging operational information concerning an optoacoustic device is further disclosed.

Abstract: An optoacoustic imaging system includes an ultrasound transducer array, first and second light sources and a switching power supply that generates power for the light sources. The switching power supply includes an input for impeding its switching operation. A data acquisition unit samples the ultrasound transducer array for a first predetermined period of time after a pulse of light from the first light source and for a second predetermined period of time after a pulse of light from the second light source and stores the sampled data. A master processor utilizes the input to impede operation of the switching operation of the switching power supply during the first predetermined period of time after a pulse of light from the first light source, and during the second predetermined period of time after a pulse of light from the second light source.

Abstract: An optoacoustic imaging system includes an ultrasound transducer array, first and second light sources and a switching power supply that generates power for the light sources. The switching power supply includes an input for impeding its switching operation. A data acquisition unit samples the ultrasound transducer array for a first predetermined period of time after a pulse of light from the first light source and for a second predetermined period of time after a pulse of light from the second light source and stores the sampled data. A master processor utilizes the input to impede operation of the switching operation of the switching power supply during the first predetermined period of time after a pulse of light from the first light source, and during the second predetermined period of time after a pulse of light from the second light source.

Abstract: Methods, tools, and systems for determining porosity in an earth formation are disclosed. Neutrons are emitted into the formation to induce inelastic scattering gamma rays and thermal capture gamma rays in the formation. The induced gamma rays are detected at a proximal gamma detector and a far gamma detector, which are spaced at different axial distances from the neutron source. A measured proximal-to-far inelastic ratio (a ratio of inelastic scattering gammas detected at the proximal and far detector) and a proximal-to-far thermal capture ratio (a ratio of thermal capture gammas detected at the proximal and far detector) are determined and used to calculate the formation porosity. Techniques are disclosed for removing borehole and casing configuration effects from the measured proximal-to-far thermal capture ratio, leaving only porosity dependence.

Abstract: Methods, tools, and systems for determining porosity in an earth formation are disclosed. Neutrons are emitted into the formation to induce inelastic scattering gamma rays and thermal capture gamma rays in the formation. The induced gamma rays are detected at a proximal gamma detector and a far gamma detector, which are spaced at different axial distances from the neutron source. A measured proximal-to-far inelastic ratio (a ratio of inelastic scattering gammas detected at the proximal and far detector) and a proximal-to-far thermal capture ratio (a ratio of thermal capture gammas detected at the proximal and far detector) are determined and used to calculate the formation porosity. Techniques are disclosed for removing borehole and casing configuration effects from the measured proximal-to-far thermal capture ratio, leaving only porosity dependence.

Abstract: Methods, tools, and systems for determining porosity in an earth formation are disclosed. Neutrons are emitted into the formation to induce inelastic scattering gamma rays and thermal capture gamma rays in the formation. The induced gamma rays are detected at a proximal gamma detector and a far gamma detector, which are spaced at different axial distances from the neutron source. A measured proximal-to-far inelastic ratio (a ratio of inelastic scattering gammas detected at the proximal and far detector) and a proximal-to-far thermal capture ratio (a ratio of thermal capture gammas detected at the proximal and far detector) are determined and used to calculate the formation porosity. Techniques are disclosed for removing borehole and casing configuration effects from the measured proximal-to-far thermal capture ratio, leaving only porosity dependence.

Abstract: A method for controlling an optoacoustic imaging system includes the steps of analyzing sinogram data values to identify variations, storing information concerning the variations, generating first and second sinograms, and processing the sinograms to mitigate the effect of the variations. In the analyzing step, sinogram data values are analyzed to identify one or more variations that are related to performance of one or more of the discrete components of the optoacoustic imaging system. The identified variations are then stored. A first sinogram is generated by sampling transducer elements acoustically coupled with a surface of a volume for a predetermined period of time after delivery of a pulse of light having a first wavelength, the first sinogram containing one channel for each of the transducer elements.

Abstract: A system and method for adjusting the light output of an optoacoustic imaging system is presented. An optoacoustic imaging system includes a light source such as a laser, the light source having a light output control, a probe for delivering light to a volume, the probe being associated with one or more sensors, a light path operatively connected to the first light source, the light path providing light from the first light source to the probe. Generally, the light output of an optoacoustic imaging system may be harmful to the eye, and may be subject to maximum safe fluence levels incident upon the volume of interest in a clinical setting. Accordingly, the light output control may be set to an initial, relatively low value. After the light source is pulsed, the light output may be measured at or near the probe at the distal end of the light path. The measured light output can used to determine whether, and how much, to change the setting of the light output control.

Abstract: Systems and methods for relaying electrical signals representing acoustic response of a volume of tissue to light and ultrasound stimulation. In an embodiment, a plurality of ultrasound transducers receive acoustic energy from the volume and generate electrical energy, which is transmitted via an electrical path to a relay system. The ultrasound transducers are operated at a wide band frequency of at least 1 MHz to 5 MHz to receive acoustic energy from the volume of tissue responsive to light stimulation and at a narrower band frequency to receive acoustic energy from the volume of tissue responsive to acoustic stimulation. The relay system relays the electrical signals to an optoacoustic system or an ultrasound instrument for further processing depending on whether the electrical signals resulted from ultrasound or light stimulation. In an embodiment, optoacoustic, ultrasound, or other images are generated from the electrical signals and may be coregistered, overlayed, or displayed.

Abstract: An optoacoustic system and method for providing enhanced laser safety includes a laser light source, a control and processing system, a laser override, and an array of optoacoustic transducers. The laser light source is capable of generating a laser light pulse upon receiving a laser light source trigger. The control and processing system is configured to generate a laser light source trigger, to receive and process ultrasound data, and to control operation of the optoacoustic system. The control and processing system determines whether received ultrasound data reflects acoustic coupling between the transducer array and the volume. The laser override is configured to automatically prevent the generation of a laser light pulse if received ultrasound data does not reflect acoustic coupling between the optoacoustic transducer array and the volume.

Abstract: Systems and methods for relaying electrical signals representing acoustic response of a volume of tissue to light and ultrasound stimulation. In an embodiment, a plurality of ultrasound transducers receive acoustic energy from the volume and generate electrical energy, which is transmitted via an electrical path to a relay system. The ultrasound transducers are operated at a wide band frequency of at least 1 MHz to 5 MHz to receive acoustic energy from the volume of tissue responsive to light stimulation and at a narrower band frequency to receive acoustic energy from the volume of tissue responsive to acoustic stimulation. The relay system relays the electrical signals to an optoacoustic system or an ultrasound instrument for further processing depending on whether the electrical signals resulted from ultrasound or light stimulation. In an embodiment, optoacoustic, ultrasound, or other images are generated from the electrical signals and may be coregistered, overlayed, or displayed.

Abstract: An optoacoustic imaging system includes an ultrasound transducer array, first and second light sources and a switching power supply that generates power for the light sources. The switching power supply includes an input for impeding its switching operation. A data acquisition unit samples the ultrasound transducer array for a first predetermined period of time after a pulse of light from the first light source and for a second predetermined period of time after a pulse of light from the second light source and stores the sampled data. A master processor utilizes the input to impede operation of the switching operation of the switching power supply during the first predetermined period of time after a pulse of light from the first light source, and during the second predetermined period of time after a pulse of light from the second light source.

Abstract: An optoacoustic imaging system includes an ultrasound transducer array, first and second light sources and a switching power supply that generates power for the light sources. The switching power supply includes an input for impeding its switching operation. A data acquisition unit samples the ultrasound transducer array for a first predetermined period of time after a pulse of light from the first light source and for a second predetermined period of time after a pulse of light from the second light source and stores the sampled data. A master processor utilizes the input to impede operation of the switching operation of the switching power supply during the first predetermined period of time after a pulse of light from the first light source, and during the second predetermined period of time after a pulse of light from the second light source.

Abstract: A serialized probe component for an optoacoustic device has a unique identifier associated therewith and includes, in an embodiment, an operative connection between a read-write memory and the optoacoustic device. Software adapted to generate and store logs in a read-write memory is executed on the optoacoustic device and stores logs concerning utilization of the serialized probe component on the read-write memory. A method for logging operational information concerning an optoacoustic device is further disclosed.