Abstract: An oxygen scanning device includes a console unit. The console unit includes a light source emitting excitation radiation and a detector configured to receive and detect phosphorescence radiation. The device includes a needle sensor operably, optically coupled to the console unit by an optical fiber movably received within a transparent tube housing the optical fiber, the transparent tube being coated by an oxygen-sensitive dye material on an outer side thereof. The optical fiber is terminated by a 45 degree reflecting surface at a distal end thereof wherein excitation radiation is directed to the oxygen sensitive dye material and phosphorescence radiation from the oxygen sensitive material is returned from the oxygen sensitive material to the detector.

Abstract: An oxygen scanning device includes a console unit. The console unit includes a light source emitting excitation radiation and a detector configured to receive and detect phosphorescence radiation. The device includes a needle sensor operably, optically coupled to the console unit by an optical fiber movably received within a transparent tube housing the optical fiber, the transparent tube being coated by an oxygen-sensitive dye material on an outer side thereof. The optical fiber is terminated by a 45 degree reflecting surface at a distal end thereof wherein excitation radiation is directed to the oxygen sensitive dye material and phosphorescence radiation from the oxygen sensitive material is returned from the oxygen sensitive material to the detector.

Abstract: A low coherence light source is used to generate a time-varying and space-localized interference pattern to excite oxygen-sensitive dye embedded in a polymer matrix inside an elongated channel waveguide. The sensing mechanism may be based on triplet-state and phosphorescence quenching of the photosensitizer dye by oxygen molecules. Phosphorescence emission resulting from the time-varying, space-localized excitation light is collected. The intensity or frequency of an oscillating component of the phosphorescence signal is used to quantify the local value of pO2 at a plurality of active measurement points along the waveguide. An oxygen sensor including the waveguide may be formed along a long axis of a needle so that a depth-resolved profile of pO2 in tissue is obtained.

Abstract: A polymer waveguide resonator device for high-frequency ultrasound detection having a optical resonator coupled to a straight optical waveguide which serves as input and output ports. Acoustic waves irradiating the waveguide induce strain modifying the waveguide cross-section or other design property. As a consequence, the effective refractive index of optical waves propagating along the ring is modified. The sharp wavelength dependence of the high Q-factor resonator enhances the optical response to acoustic strain. High sensitivity is demonstrated experimentally in detecting broadband ultrasound pulses from a 10 MHz transducer.

Abstract: A method of measuring fluorophore excited state lifetimes comprising initiating an excitation laser pulse at a dye to excite dye molecules of the dye from a ground state to an excited state and initiating a probing pulse at the dye molecules thereby generating a first set of photoacoustic waves at a first time delay resulting in a first intensity point. The process can be repeated, optionally introducing a second excitation laser pulse, to generate a second set of photoacoustic waves at a second time delay resulting in a second intensity point. The data can be analyzed to determine a slope between the first intensity point and the second intensity point.

Abstract: A method of measuring fluorophore excited state lifetimes comprising initiating an excitation laser pulse at a dye to excite dye molecules of the dye from a ground state to an excited state and initiating a probing pulse at the dye molecules thereby generating a first set of photoacoustic waves at a first time delay resulting in a first intensity point. The process can be repeated, optionally introducing a second excitation laser pulse, to generate a second set of photoacoustic waves at a second time delay resulting in a second intensity point. The data can be analyzed to determine a slope between the first intensity point and the second intensity point.

Abstract: A method and apparatus for controlling access of individuals to a service, device or location in order to restrict access to members of a particular age and/or gender category, by machine-sensing a predetermined biometric characteristic of the individual indicative of the particular age and/or gender category, and utilizing the machine-sensed characteristic for automatically controlling access of the individual. The method and apparatus are particularly suited to controlling access of children to certain Internet sites, TV programs, chat rooms, or other places inappropriate to children.

Abstract: A polymer waveguide resonator device for high-frequency ultrasound detection having a optical resonator coupled to a straight optical waveguide which serves as input and output ports. Acoustic waves irradiating the waveguide induce strain modifying the waveguide cross-section or other design property. As a consequence, the effective refractive index of optical waves propagating along the ring is modified. The sharp wavelength dependence of the high Q-factor resonator enhances the optical response to acoustic strain. High sensitivity is demonstrated experimentally in detecting broadband ultrasound pulses from a 10 MHz transducer.

Abstract: Apparatus for assaying an analyte of blood in a patient's blood vessel comprising: a mounting module adapted so that it can be adhered to the skin of the patient overlying a tissue region comprising the blood vessel; a sensor unit mounted to the module that generates signals responsive to characteristics of the tissue region; and a controller that receives the signals and uses received signals to assay the analyte and to determine a degree to which the sensor unit is aligned with the blood vessel.

Abstract: A method for determining an acoustic velocity in a segment of a bone covered with a layer of soft tissue having an outer surface, which includes determining a first travel time of a first ultrasonic wave along a first path from the outer surface back to the outer surface which path includes at least a first part of the bone segment together with determining a second travel time of a second ultrasonic wave along a second path from the outer surface back to the outer surface, which path includes at least a second part of the bone segment and also determining a third travel time of a third ultrasonic wave along a third path from the outer surface back to the outer surface which path includes at least a third part of the bone segment, and deriving the acoustic velocity in the segment of bone from the three determined travel times.

Abstract: A system for monitoring a position of an instrument in a subject includes a light transmission medium configured to transmit light pulses to a desired region to produce an acoustic signal, at least one ultrasound sensor configured to receive the acoustic signal and to produce a transduced signal from the acoustic signal, and a processing unit connected to the at least one ultrasound sensor and configured to locate a source of the acoustic signal using the transduced signal.

Abstract: A method of determining a portion of light at a given wavelength which is incident on a material that is absorbed by the material, the method comprising: transmitting a pulse of light at the given wavelength so that the pulse traverses a path through the material; generating a first signal responsive to light in the light pulse that traverses the path length without being absorbed by the material; generating a second signal responsive to energy that the material emits responsive to a portion of the light from the light pulse that is absorbed by the material as the light pulse traverses the path; and using the first and second signals to determine the absorbed portion.

Abstract: A system for monitoring a position of an instrument in a subject includes a light transmission medium configured to transmit light pulses to a desired region to produce an acoustic signal, at least one ultrasound sensor configured to receive the acoustic signal and to produce a transduced signal from the acoustic signal, and a processing unit connected to the at least one ultrasound sensor and configured to locate a source of the acoustic signal using the transduced signal.

Abstract: A method and apparatus for controlling access of individuals to a service, device or location in order to restrict access to members of a particular age and/or gender category, by machine-sensing a predetermined biometric characteristic of the individual indicative of the particular age and/or gender category, and utilizing the machine-sensed characteristic for automatically controlling access of the individual. The method and apparatus are particularly suited to controlling access of children to certain Internet sites, TV programs, chat rooms, or other places inappropriate to children.

Abstract: A method and apparatus for controlling access of individuals to a service, device or location in order to restrict access to members of a particular age and/or gender category, by machine-sensing a predetermined biometric characteristic of the individual indicative of the particular age and/or gender category and utilizing the machine-sensed characteristic for automatically controlling access of the individual. The method and apparatus are particularly suited to controlling access of children to age-inappropriate Internet sites.