Abstract: An optical coherence imager for use in a clinical environment includes a laser source (24) for illuminating an area of tissue surface and a detector array (28) arranged to generate output signals indicative of detected light scattered from the tissue surface. An optical coherence image, such as a Flux image that is indicative of blood perfusion in the tissue, is generated from data collected at the detector. Detector output is analysed to identify a time series of such optical coherence images during which relative movement between tissue and detector is favourable. A representative optical coherence image is formed from an average of optical coherence images generated from data collected within the identified time series and extending over a period of multiple heartbeats. The representative optical coherence image thereby exhibits minimal movement noise and the effects of heartbeat are averaged out.

Abstract: An optical coherence imager for use in a clinical environment includes a laser source (24) for illuminating an area of tissue surface and a detector array (28) arranged to generate output signals indicative of detected light scattered from the tissue surface. An optical coherence image, such as a Flux image that is indicative of blood perfusion in the tissue, is generated from data collected at the detector. Detector output is analysed to identify a time series of such optical coherence images during which relative movement between tissue and detector is favourable. A representative optical coherence image is formed from an average of optical coherence images generated from data collected within the identified time series and extending over a period of multiple heartbeats. The representative optical coherence image thereby exhibits minimal movement noise and the effects of heartbeat are averaged out.

Abstract: An apparatus for measuring and imaging blood perfusion in tissue comprises a monochromatic laser light source, means for shaping the laser light beam, means for irradiating a section of the surface of the tissue with the laser light beam, means for collecting light scattered from the irradiated section, an image sensor comprising a plurality of photodetectors, each photodetector of the sensor being able to receive collected light from a predetermined sub area of the section of the tissue surface and produce a corresponding electrical output signal linearly related to the detected instananeous laser light intensity; means for processing the electrical output signals from the plurality of photodetctors, means for calculating the average Doppler frequency shift for each sub area from which scattered light is detected, means for producing an image of the blood perfusion in the tissue section irradiated from the processed output signals, and an image display means.

Abstract: Blood perfusion in tissue is imaged using a beam from a monochromatic laser light source that is scanned over the tissue surface in a predetermined pattern at a substantially constant speed. Light scattered from the tissue surface is collected. The position of the beam can be determined and recorded at any point of the scan, and the beam can be halted at a predetermined position or positions during the scan. Two or more photodetectors are positioned to collect light diffusely scattered from the tissue surface such that specularly reflected light is detected by either no detector or by only one detector at a given time. Electrical signals from the photodetectors are processed, and saturation of a photodetector is registered. The saturated photodetector is eliminated from the signal processing to ensure that only unsaturated photodetector signals are processed. The blood perfusion measurements are recorded and displayed.

Abstract: An apparatus for measuring microvascular blood flow in tissue including a monochromatic light source arranged to irradiate a section of the tissue with the monochromatic light from the light source, a photodetector arranged to collect light scattered from the irradiated section, a processor for processing the electrical output signals from the photodetector, calculating the power spectrum of photocurrents generated in the detection of laser light scattered from static tissue and Doppler broadend laser light scattered from moving blood cells, and recording the average Doppler frequency shift, and further calculating and recording the blood concentration. The apparatus further measures and records the intensity of the detected scattered light, calculates and records the blood perfusion (flux), filters movement artefact noise, and displays the blood perfusion measured parameters. By filtering movement artefact noise, the apparatus enables fast tissue blood perfusion monitoring with enhanced signal quality.