WO2011070357A1 - Appareil de mesure de paramètres sanguins - Google Patents

Appareil de mesure de paramètres sanguins Download PDF

Info

Publication number
WO2011070357A1
WO2011070357A1 PCT/GB2010/052045 GB2010052045W WO2011070357A1 WO 2011070357 A1 WO2011070357 A1 WO 2011070357A1 GB 2010052045 W GB2010052045 W GB 2010052045W WO 2011070357 A1 WO2011070357 A1 WO 2011070357A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
detector
multispectral
laser
blood flow
Prior art date
Application number
PCT/GB2010/052045
Other languages
English (en)
Inventor
Matthias Kohl-Bareis
Branislav Ebert
Jens P. Dreier
Christoph Leithner
Ute Lindauer
Georg Royl
Original Assignee
Moor Instruments Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Moor Instruments Ltd filed Critical Moor Instruments Ltd
Priority to EP10796119A priority Critical patent/EP2509491A1/fr
Priority to US13/514,376 priority patent/US20120277559A1/en
Publication of WO2011070357A1 publication Critical patent/WO2011070357A1/fr

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/026—Measuring blood flow
    • A61B5/0261—Measuring blood flow using optical means, e.g. infrared light

Definitions

  • This invention relates to the field of blood imaging and monitoring and to apparatus for the simultaneous imaging or monitoring of haemoglobin concentration and blood flow, particularly in the small superficial blood vessels of body tissue.
  • Haemoglobin is one of the central components of the body and is of crucial importance to all body functions. Blood flow in the small vessels of the skin performs an essential role in the regulation of the metabolic,
  • the condition of the microcirculation over both long and short time periods can reflect the general state of health.
  • the degree of blood perfusion in the cutaneous microvascular structure often provides a good indicator of peripheral vascular disease and reduction of blood flow in the microcirculatory blood vessels can often be attributed to cutaneous vascularisation disorders. There are therefore many situations in routine clinical medicine in which measurement of the blood flow is important.
  • tissue may be any organ of living humans or animals, for example, skin, brain or muscle.
  • the tissue status may change with time, or over a spatial area. Simultaneous measurement of both haemoglobin and blood perfusion (flow) is important when transient changes are to be monitored. This is particularly the case during any functional activation where changes might last just a few seconds.
  • haemoglobin For example, during cortical activation of brain tissue there is a well-described change in haemoglobin that is both localised and may be of short duration. Another example is in the body's response to exercise, stress or heat: skin or muscular tissue changes are induced but fade over a short period as the body adapts. In such cases a sequential measurement of haemoglobin and blood flow would provide data of limited value. In addition, some physiologically important
  • Haemoglobin concentrations can occur in both oxygenated [oxyHb] and deoxygenated [deoxyHb] form.
  • the absorption spectra of these forms differ, as can be observed by comparing the appearance of oxygenated and deoxygenated blood.
  • Standard techniques to measure or monitor haemoglobin concentrations and its oxygenation exploit this.
  • Pulse oximetry is a convenient and well known example that measures the oxygen saturation in arterial blood from a pulsatile component of reflected light.
  • This present invention is concerned with measurement of blood oxygenation and flow in the microcirculation. That is, oxygen saturation and flow in the capillaries, associated with nutritional flow, and in the small arteries and veins associated with both nutritional and
  • thermoregulatory flow
  • Concentration measurements taken at sample points over a tissue surface area can be used to construct a two-dimensional image. Multiple images of the area may be taken in successive time periods in order to construct a video image, or other time-dependent data collection. Physiologically meaningful information can be extracted either from the time course of different images and / or from different regions of interest in an image.
  • haemoglobin concentration can be monitored by taking a single site (pixel) measurement.
  • Monitoring enables data to be collected more rapidly than for imaging, which in turn permits a more accurate time-resolution of physiological changes.
  • tissue oxygenation during sport or exercise may be assessed by monitoring and, in a different setup, brain monitoring provides a useful tool in babies undergoing cardiac surgery.
  • US 2007/0024946 describes use of a hyperspectral camera to image haemoglobin concentrations. Such a camera is however costly and operates only at a relatively slow frame rate. If the frame rate is too slow, then problems arise with tissue surface movements or displacements during recording of an image. Izumi Nishidate et al.
  • Blood flow in the microcirculation is conventionally measured by observing the scattering of monochromatic and coherent light from blood cells moving in illuminated tissue.
  • Laser light that is incident on tissue typically the skin surface, is scattered by moving red blood cells and undergoes frequency broadening.
  • Two basic techniques are used to analyse this effect: laser Doppler and speckle contrast.
  • the frequency broadened laser light together with laser light scattered from static tissue, is detected and the resulting photocurrent processed to provide a measurement of the average frequency shift that correlates with blood flow.
  • the laser speckle technique observes another manifestation of the frequency broadening, a time-varying speckle pattern.
  • the contrast in the pattern is high for low blood-flow areas and low for high blood-flow areas. Mapping the speckle contrast over a surface area enables a two-dimensional image of blood perfusion to be recorded.
  • the optical path length of light in tissue is wavelength dependent.
  • wavelengths can be used to provide information on blood flow at different depths below the tissue surface.
  • EP 949 880 describes a system capable of real-time display of perfusion over an area of tissue.
  • the present invention provides an apparatus for the simultaneous measurement of blood flow and chromophore concentration, the apparatus comprising:
  • a multispectral light source for illuminating an area of tissue surface
  • a laser source for illuminating the area of tissue surface
  • a detector system for detecting light scattered from the tissue, the detector system being arranged to produce a first signal output obtained from detected laser light and a second signal output obtained from detected multispectral light;
  • the detector system includes a multispectral detector sensitive to light from a range of visible wavelengths to generate the second signal, the signal comprising two channels indicative of light in two respective visible wavelength bands, one of which is a red spectral band.
  • An important feature of this invention is the ability to extract useful information regarding chromophore concentration using a multispectral detector, which is responsive to light across a range of wavelengths.
  • This broadband detector is preferably a red-green-blue (RGB) detector sensitive to light across the visible spectrum. This is in contrast to many prior art systems in which, more costly, optical filters are used to ensure a narrowband detector response.
  • the detectors used in the present invention may, for example, be charge couple device (CCD) or
  • CMOS complementary MOSFET
  • the light source supplying the detected signal from which chromophore concentration measurements are made, is similarly multispectral.
  • multispectral it is meant that the light emitted occupies two or more wavelength bands of the red-green-blue colour spectrum.
  • the source itself could be a white light source, occupying a bandwidth of around 250 nm, blue through to red. Equally however it could comprise separate LEDs each emitting a wavelength spread of 20 nm to 100 nm (broadband) in one of the red-green-blue parts of the spectrum. Alternatively, it may comprise separate laser sources, each now emitting a narrow bandwidth, but again constrained to occupy distinct (red, green or blue) parts of the visible spectrum. All that is required is that multispectral light is scattered from tissue, enabling detection of separate spectral components by the detector system.
  • the multispectral light source may emit light in two wavelength bands, corresponding with those used by the multispectral detector to generate the second signal. This then allows the laser source to be arranged to emit light at a wavelength outside these two bands. This may be in the third visible band or, for some applications, in a near infrared spectral band. It is a further novel feature of this invention that allows chromophore
  • the present invention provides apparatus for the measurement of chromophore concentration, the apparatus comprising:
  • a multispectral light source emitting light in two spectral bands, one of which is a red spectral band, for illuminating an area of tissue surface; a detector system for detecting light scattered from the tissue, the detector system being arranged to produce a signal output obtained from detected multispectral light; and
  • the output signal used by the signal processing apparatus containing no information derived from light outside the two spectral bands.
  • the combination of these two aspects of the invention results in a particularly powerful tool. Restricting the spectral content of light used for chromophore measurement to two spectral bands and the spectral content of the laser light used for blood flow measurement to a separate band allows ready separation at the detector of the signals for processing. This eases processing requirements and increases potential frame rates, as the illumination will not need to be switched between sources, as in the prior art, to avoid the signals mixing.
  • the multispectral source used in this apparatus may be provided in a number of ways. It may comprise a first light emitting diode (LED) emitting light in the red spectral band and a second LED emitting light in either a blue or a green spectral band.
  • the broadband (typically 20 nm - 100 nm) LEDs may be replaced with narrowband laser sources.
  • the source may be a continuous spectrum source used in combination with a filter arranged to block transmission of light in either a blue or a green spectral band. Suitable continuous spectrum sources are: white light LED, fluorescent lamp or incandescent lamp.
  • the third visible band (green or blue) is, of course, also available for use.
  • the laser light that is needed for simultaneous measurement of blood flow and chromophore concentration may advantageously be at a wavelength that occupies the third band.
  • information obtained from the third band is used to improve the accuracy of the chromophore measurement, in which case, the multispectral source may comprise first, second and third light emitting diodes (LEDs) emitting light in, respectively, red, blue and green spectral bands.
  • the multispectral source may comprise red, blue and green lasers emitting narrowband light in, respectively, red, blue and green spectral bands.
  • the source may be a continuous spectrum source.
  • the signal processing apparatus may additionally used to extract information relating to concentration of a second chromophore from the second output signal. That is, the third band may provide information that, used either alone or in conjunction with information obtained from another band, allows calculation of the concentration of a second, naturally occurring, chromophore species.
  • the additional available data may be used to extract information relating to concentration of an injected dye.
  • Dyes are commonly used in medical treatment to track flow of a substance through part of the body. Being able to image dye concentrations along with, for example, haemoglobin concentrations and blood flow, offers a powerful aid to diagnosis and /or to understanding of body performance.
  • the laser light and multispectral light occupy different bands, this may not always be the case. If they do occupy the same bands, then illumination will need to be switched between sources in order to avoid corruption of one data signal with another.
  • Switching may also be optionally implemented with band separation.
  • the multispectral detector preferably comprises a 2-dimensional array of detector elements and the signal processing apparatus is arranged to analyse signals obtained from at least two channels of each detector element and so to obtain information regarding chromophore concentration at sample points relating to each detector element and to output said information to an imaging apparatus arranged to display an image of chromophore concentration.
  • Corresponding detector elements may also be used to image blood flow.
  • the multispectral detector is preferably responsive to provide a single data signal and the signal processing apparatus is arranged to monitor variations in said signal and hence of chromophore concentration.
  • the chromophore is oxyhaemoglobin and / or deoxyhaemoglobin.
  • the signal processing apparatus may be further arranged to extract information relating to blood oxygen saturation of and / or the metabolic rate of oxygen within the illuminated tissue.
  • blood flow information may be extracted from infrared illumination of tissue.
  • the detector system should include an IR detector, whose output is used to generate the signal from which blood flow is extracted.
  • Blood flow information may be extracted from the first (laser) output signal using a variety of known techniques such as laser speckle contrast, speckle temporal variation or a laser Doppler technique.
  • the present invention provides a method of
  • the method comprising the steps of: (a) Illuminating an area of tissue surface with a multispectral light source;
  • wavelengths including that of the laser and at least two component bands of the multispectral source; (d) Calculating blood flow information from scattered laser light; and (e) Calculating chromophore concentration from scattered light from at least two component bands of the multispectral source.
  • Steps (a) and (b) may be carried out concurrently, or alternately (switched).
  • Figure 1 is a schematic illustration of a first embodiment of a system for imaging blood flow and haemoglobin concentration in accordance with the present invention.
  • Figure 2 is a schematic illustration of a second embodiment of an imaging system in accordance with this invention.
  • Figure 3 is a schematic illustration of a third embodiment of an imaging system in accordance with this invention.
  • Figure 4 is a schematic illustration of a layout of a monitor for monitoring blood flow and haemoglobin concentration in accordance with the present invention.
  • Figure 5 is a schematic illustration of a fourth embodiment of an imaging system in accordance with this invention.
  • Figure 6 is a schematic illustration of a fifth embodiment of an imaging system in accordance with this invention.
  • Figure 7 is a schematic illustration of a sixth embodiment of an imaging system in accordance with this invention.
  • Figure 8 is a schematic illustration of a layout of a second embodiment of a monitor for monitoring blood flow and haemoglobin concentration in accordance with the present invention.
  • Figure 9(a) is a graphical plot illustrating the spectral dependence of extinction spectra of oxyHb and deoxyHb over a wavelength range 400 nm to 700 nm.
  • Figure 9(b) is a graphical plot illustrating the spectral dependence of sensitivity spectra of ⁇ ( ⁇ ) over a wavelength range 400 nm to 700 nm for blue, green and red elements of a typical RGB detector for use with certain embodiments of this invention.
  • Figure 9(c) is a graphical plot illustrating the spectral variation over a wavelength range 400 nm to 700 nm of a typical white light source for use with certain embodiments of this invention.
  • Figure 10 is a graphical plot illustrating a modelled wavelength dependence of mean photon path length through tissue.
  • Figures 1 1 (a) - (d) are plots showing condition number, an indicator of robustness of a model applied to this invention, for two-wavelength systems, subject to various path length and detection bandwidth
  • Figure 12 shows two plots of condition number variation with wavelength of a first wavelength for four selected second wavelength values in a two- wavelength system.
  • Figures 13(a) - (h) are plots showing condition number variation for various three-wavelength systems.
  • Figure 14 is a plot showing a cross section of condition number variation with a first wavelength for selected second and third fixed wavelength values in a three-wavelength system.
  • Figure 15(a) is a plot of measured attenuation change with time in a rat cortex using apparatus in accordance with the present invention, following electrical stimulation (stimulus signal shown overlaid) of a rat forepaw, the plot showing respective measurements for each channel (R,G,B) of an RGB camera detector.
  • Figure 15(b) is a graph showing haemoglobin concentrations (for both deoxyHb and oxyHb species) over the same time frame used for Figure 15(a) the concentrations calculated using either RGB-, RB- or RG-signals shown in Figure 15(a).
  • Figure 16(a) is a graph showing concentration changes of deoxyHb and oxyHb at two spatially separated points (P1 , P2) in a rat cortex, following stimulation as for Figure 15.
  • Figure 16(b) is a series of grey scale images of oxyHb and deoxyHb concentrations in a rat cortex following forepaw stimulation, the images being generated using apparatus in accordance with this invention.
  • Figure 17 shows, at its left, an image of a rat cortex indicating two regions of interest (ROI 1 & 2) and, at its right, plots of respectively, oxyHb concentration, deoxyHb concentration and blood flow changes with time as measured at these regions of interest using apparatus in accordance with this invention, following application of a stimulus.
  • Figure 18 is a flow chart representing steps involved in implementing an algorithm to extract blood flow data from laser light scattered and reflected from tissue.
  • FIG 19 is a schematic illustration of a system for extracting flux information, suitable for incorporation in an embodiment of the present invention.
  • a system 10 for imaging blood flow and haemoglobin concentration in accordance with this invention.
  • the system 10 comprises a visible light laser 12 and polychromatic (white) light source 14 whose light is directed by lenses 16, 18 to illuminate a section of tissue surface 20.
  • Light reflected from the surface 20 is collected by a lens 22 and detected by an RGB-CCD (Red, Green, Blue - Charge Coupled Device) detector array 24.
  • the RGB array 24 detects red, green and blue components of light incident on each element of the array.
  • the detected signals are read by a signal processor (not shown) and analysed to extract the required information for each pixel in an image. The analysis process will be described in more detail later.
  • Images are output to a monitor (not shown) for display.
  • the display may be, for example, a false colour image viewed in real time at video frame rates.
  • Haemoglobin concentrations are extracted by a spectroscopic analysis of light detected from the white light source.
  • Blood flow measurements are extracted from data obtained from a speckle contrast analysis of light detected from the laser source.
  • the tissue surface 20 is not illuminated continuously with both light sources 12, 14.
  • the white light source 14 is switched off or blanked while the speckle contrast
  • a second embodiment of the invention is illustrated in Figure 2.
  • the white light source 14 and lens 18 are replaced by a ring lamp LED 26 white light source.
  • two CCD cameras are used to detect the reflected light and the laser 12 is a near infrared laser.
  • a first camera 24a is the RGB-CCD camera detector array as used in the previous embodiment, from which information as to haemoglobin concentration may be derived.
  • a second camera 24b is a near infrared (NIR) detector array, sensitive to a wavelength range that includes that emitted by the NIR laser 12.
  • a dichroic beam splitter 28 directs visible light to the RGB-CCD array 24a and the IR reflected signal to the NIR camera 24b. The signal detected at the NIR camera 24b is used to obtain a speckle-contrast flow measurement.
  • This embodiment has the advantage that the sensitivity of the speckle contrast flow measurement is significantly improved in comparison with the measurement taken with visible light. Moreover the use of separate detectors means that there is no need to interrupt the white light
  • the tissue surface can be continuously illuminated by both the white light and NIR laser source. This enables more rapid data collection and so offers the potential for a faster frame rate.
  • Camera frame rate is very important to haemoglobin concentration and blood flow imaging.
  • Blood flow is inherently time-changing and, as mentioned previously, both flow and haemoglobin concentration can change over a short timescale. Imaging at a higher frame rate enables more accurate variations with time to be extracted.
  • a laser 12 of alternative, for example near- visible, wavelength is used.
  • the dichroic beam splitter 28 separates this near-visible light from that of the LED white light source.
  • the beam splitter 28 should be such that it separates incident light into two wavelength bands: one band including the wavelengths of the white light source and the other band the wavelength of the laser source.
  • the detected signal is processed and analysed by the signal processing apparatus in order to extract data relating to blood flow and haemoglobin concentration.
  • Data is collected from each element in the 2D camera array, the signals (RGB and laser) analysed and the results displayed as a 2D image. The calculation is repeated at successive time intervals, and the displayed image updated and the data stored.
  • Laser speckle contrast measurements can be made in either of two modes: low resolution spatial processing or high resolution temporal processing.
  • Spatial processing involves the analysis of the intensity variation within small groups (typically 5x5) of pixels within a single frame of image data.
  • Temporal processing involves the analysis of the intensity variation of single pixels over a number of frames (typically at least 25) of image data.
  • temporal processing is capable of generating images with high resolution at relatively low speed, whereas spatial processing generates images with reduced resolution at high speed.
  • the speckle contrast measurements made in these embodiments are extracted using spatial processing. That is, a 2D detector is required with resolution higher than displayed in the image. This provides the potential for relatively high frame rate data collection, which is of course beneficial to situations in which simultaneous measurement of haemoglobin and blood flow are made.
  • RGB-CCD cameras of the type used to image the haemoglobin are available that operate at comparable frame rates.
  • a balance is made between camera cost and the desire for high frame rates. Even without the requirement for Doppler laser flow measurements, imaging temporal resolution can be improved at a higher frame rate.
  • a linear detector array may be used for imaging.
  • a linear detector imager (LDI) can be operated at faster frame rates for considerably less cost than a 2D camera. Consequently, it may find application in many situations.
  • FIG 4 illustrates the components of the invention integrated into a small, portable monitor 30.
  • the monitor 30 comprises a white light LED source 32, a single-mode NIR laser diode 34, separate RGB photodiodes 36a, 36b, 36c and a NIR sensitive photodetector 38.
  • this embodiment is intended for monitoring only and, as such, uses only point detection.
  • a single photodetector element per channel is used, as opposed to the linear or 2D arrays. As can be seen from the scale included with this figure, these detector elements are ⁇ 1 mm long.
  • the signals detected from the white light source 32 by the RGB photodiodes 36a, 36b, 36c are used to extract haemoglobin concentration measurements.
  • the signal detected from the laser diode 34 at the NIR photodetector 38 is, again in contrast to the imaging embodiments described above, used to extract laser Doppler blood flow measurements.
  • a switching mechanism (not shown) may be included to switch illumination between white visible light and NIR.
  • filters (not shown) may be placed over the RGB detectors 36a, 36b, 36c to remove NIR light and over the NIR detector 38 to remove visible light. Continuous illumination may then be used.
  • the NIR laser diode 34 is replaced by a visible laser diode and the NIR detector removed.
  • the white light detection system can be three separate R, G and B detectors, as shown, or a single RGB silicon diode detector.
  • the monitor as described with reference to Figure 4 is small and compact and, ideally, suitable for attachment to a patient or animal, with minimal inconvenience.
  • the monitor described above uses a point detector that is a compact arrangement of single photodetector elements for each of the wavelength bands used.
  • Alternative monitors may use different techniques to extract a point measurement: for example a single pixel region may be used from a 2D detector array, or a region of interest may be defined by a block of pixels on a 2D array, and the signals detected over the area of the block averaged to obtain a single measurement.
  • the imaging embodiments of this invention make use of spatial processing of the speckle contrast image.
  • the monitoring embodiment uses a laser Doppler technique, which is advantageous in that it requires only a single element detector.
  • the photodiode can accordingly be very close or in direct contact with the tissue under investigation.
  • the laser Doppler technique directly detects the frequency spread of scattered light from a Fourier transform of a time-resolved signal.
  • a high-frame rate (> 5 kHz, ideally) detector must be used.
  • High frame rate 2D imaging detectors are available, but these are not standard and are costly.
  • the output of a single detector element on the other hand can be sampled electronically at suitably high frame rates, which makes the monitor embodiment suitable for implementation with laser Doppler blood flow measurement.
  • Temporal laser speckle contrast imaging may be used in place of the laser Doppler in the monitor embodiment. This may increase slightly the size of the device as more optical components are required.
  • the detected signals from the monitor channels are processed and analysed by the signal processing apparatus in order to extract data relating to blood flow and haemoglobin concentration of a small region of tissue surface. The calculation is repeated at successive time intervals, and the measurement accordingly updated.
  • the intensities of the RGB components of detected light, relative to a reference intensity are sufficient to extract information regarding haemoglobin concentration. That this relatively crude spectroscopic analysis is a viable approach was first demonstrated by Izumi Nishidate et al., referenced above.
  • Additional embodiments of this invention therefore make use of two visible channels: red and blue or red and green to detect illuminating white light or otherwise multispectral light and one further detector channel: either NIR or the unused visible channel, as befits the laser, to detect the laser light.
  • red and blue or red and green to detect illuminating white light or otherwise multispectral light
  • one further detector channel either NIR or the unused visible channel, as befits the laser, to detect the laser light.
  • Use of fewer detectors not only permits the device to be simpler, but also reduces the signal processing requirements.
  • FIG. 5 An embodiment of the invention that uses three visible channels to measure simultaneously haemoglobin concentration and blood flow is shown in Figure 5.
  • This embodiment differs from that shown in Figure 1 in that the polychromatic (white) light source is replaced by a source 39 consisting of a pair of LED sources, one of which emits broadband radiation in the red part of the visible spectrum and the other emits broadband radiation in the green part of the spectrum.
  • Light from this dual- band source 39 is directed by lens 18 to illuminate a section of tissue surface 20
  • the laser source 12 in this embodiment generates a beam of light in the blue part of the visible spectrum.
  • Laser light is directed by lens 16 to illuminate the same area of tissue as that illuminated by the dual- band source.
  • RGB-CCD Red, Green, Blue - Charge
  • Coupled Device detector array 24 The RGB array 24 detects red, green and blue components of light incident on each element of the array. The detected signals are read by a signal processor (not shown) and analysed to extract the required information for each pixel in an image, which is then sent to a display..
  • Haemoglobin concentrations are extracted by a spectroscopic analysis of light detected from the red-green dual-band light source. Blood flow measurements are extracted from data obtained from a speckle contrast analysis of light detected from the blue laser source. This arrangement enables separation of the two signals at the detector.
  • the RGB array 24 will output three channels per pixel. Data received on the red and green channel is used to derive the haemoglobin concentration; data received on the blue channel is used to derive the blood flow.
  • This arrangement therefore avoids the need for switching, which enables data to be collected continuously relating to both measurement parameters, which in turn offers the potential for a faster imaging frame rate. Better time resolution is therefore available, enabling improved imaging of dynamic events.
  • This arrangement also makes use of a single broadband detector, which may be of a type that is readily and relatively cheaply available.
  • the laser source emits in the green part of the visible spectrum and the dual-band LED source emits in both the red and blue spectral bands. Measuring blood flow using green light enables the measurement to be made at a different depth below the tissue surface from that obtained using blue light. Again, the received signals occupy three distinct spectral bands, enabling their ready separation to obtain haemoglobin and blood flow measurements without the need for switching.
  • the dual-band LED source 39 may be replaced with a white light source used in conjunction with a blue light stop band filter. This filter absorbs light in the blue spectral band, with the result that illumination from this source is again dual-band red-green. If the laser source 12 emits blue light, signal separation may again be readily achieved at the detector 24.
  • a green laser source 12 may be utilised with a white light source in conjunction with a green light stop band filter.
  • the change in intensity of light scattered from the tissue is measured relative to a reference reading.
  • haemoglobin will be used as a specific example both for clarity and because it is the measurement of haemoglobin concentration that is seen as the primary application of this invention.
  • the index j indicates oxyHb and deoxyHb.
  • e ⁇ (X) is the extinction coefficient for each chromophore j
  • D ⁇ (k) represent the sensitivity spectrum of each detector element S(X) is the normalised intensity spectrum of the light source
  • ⁇ _( ⁇ ) is the photon mean free path length through the tissue.
  • each of these parameters can either be modelled or obtained empirically and this therefore allows the concentration changes Ac i to be calculated by matrix inversion from observation of attenuation changes.
  • the extent of the spectroscopic analysis can be reduced to only two chromatic observations: red with either green or blue.
  • only two detectors or detector elements (RB or RG) need be used to detect signals from which the haemoglobin concentrations are extracted.
  • the third (G or B) may be used to detect the laser signal that provides an indication of blood perfusion when the laser wavelength is adapted to fall within the detection wavelength band.
  • An embodiment utilising a white light source will require switching between sources in order to avoid the white light detected at the third (G or B) detector from corrupting the reading obtained from the laser signal.
  • the white light is filtered or only two LED sources are used, in order that only the laser light contributes to the intensity in this band.
  • Blood flow measurement is, in accordance with this invention, based on one of two methods: speckle contrast tissue perfusion and laser Doppler blood flow measurements.
  • speckle contrast K the intensity at each pixel (spatial or temporally separated) is measured.
  • the ratio of the standard deviation of each pixel intensity to the mean intensity defines the speckle contrast K.
  • the speckle contrast method assumes that blood perfusion is proportional to the mean velocity v of blood flow. It follows therefore that perfusion is inversely proportional to the correlation time x c of photons within the tissue. Correlation time x c may be related to speckle contrast K by the following equation, where T is the integration time of the camera:
  • speckle contrast K can vary between 0 (no speckle, very high perfusion) and 1 (fully developed speckle, very low perfusion).
  • Reflected and scattered light from moving blood comprises two components: one of which is unchanged in frequency and the other of which has a Doppler broadened frequency due to interactions with moving blood cells in the microvasculature of the tissue.
  • This approach uses digital signal processing to analyse a time-varying intensity signal output from a detector to extract information as to frequency spread. The signal is generally weighted by a multiplier, for example co, and then Fourier Transformed to produce a measure of the noise
  • ni and n 2 are lower and upper limits of frequency components in the computation
  • Noise is the system noise which includes dark noise (DN) and DC proportional shot noise (SN).
  • DC is a measurement of the intensity of the collected scattered light.
  • Figures 6, 7 and 8 show embodiments of this invention suitable for simultaneous detection of haemoglobin concentrations and blood perfusion extracted from speckle contrast imaging.
  • an LED white light source 14 and laser 12 arranged to illuminate an area of tissue. Reflected and scattered light passes through a filter 40, lens 41 to a single RGB-CCD camera detector array 42.
  • a computer (not shown), the camera 42 or other microprocessing device directs the LED 14 and laser 12 to be switched on and off alternately, and signal data to be collected, in accordance with a prescribed timing pattern.
  • the timing pattern is shown in an offset diagram 43 to the right, with time indicated along a horizontal axis. Data signals are read from the RGB detector at intervals, as indicated by lines 44.
  • the filter 40 suppresses unwanted light from reaching the detector 42. In some embodiments, it may be a polarising filter that blocks specularly reflected light. In others, it may be an absorbing filter to block stray ambient light, or a combination of both.
  • the data collected during LED illumination and during laser illumination are collected, processed, analysed and stored by a device such as a computer, microcomputer, microcontroller or similar. Signal data are used to construct images indicating blood perfusion and haemoglobin
  • the output images are sent for display.
  • the tissue 20 is again illuminated with the white light source 14 and laser 12. Reflected and scattered light passes through a filter 40, lens 41 to a beam splitter 45.
  • the beam splitter 45 is dichroic in that it transmits light of one wavelength band, that detected by the RGB camera 42, and reflects light of the other wavelength band to a second camera 46.
  • This second camera 46 is sensitive to light outside the RGB wavelength range (see offset diagram 47), for example to light in the near infrared, which includes the wavelength of the laser source 12.
  • Both cameras 42, 46 and associated optics 40, 41 , 45 may be integrated in one housing or separate.
  • the LED 14 and laser 12 are permanently on during data collection, and the detector signals are sampled at regular time intervals, as shown in the timing diagram 48.
  • a computer or similar microprocessing unit collects data from both the RGB camera 42 and NIR camera 46. That collected from the RGB camera 42 is processed and analysed to extract information relating to the haemoglobin concentration and that collected from the NIR camera 46 is used to perform speckle imaging in order to extract perfusion data. Both results are imaged, simultaneously or otherwise, under command of a user.
  • the beamsplitter 45 is not dichroic and splits both parts of the illuminating spectrum, both detectors therefore receiving light from the entire illuminating range. In this embodiment therefore it is important to ensure that the cameras 42, 46 remain insensitive to wavelengths outside their nominal detection range.
  • the apparatus may be adapted to take measurements of blood flow using a visible wavelength laser. Timings would then have to be such that the sources are switched on and off alternately, as shown for the embodiment in Figure 6. Two detectors still provide an advantage over one detector, which could of course be sufficient in a switching system, in that image acquisition is quicker and signal to noise ratio reduced.
  • a currently-available commercial camera may be used or adapted.
  • the commercial camera is equipped with filters and three imaging devices: one to detect each of R, G and B.
  • the addition of a further imaging device for NIR (or other wavelength) speckle detection is feasible.
  • Such an imaging system may be used with three monochromatic laser sources, Red, Green and Blue, for both haemoglobin concentration measurements and speckle contrast blood flow measurements in the three visible wavelength bands.
  • the addition of a fourth image sensor would allow blood flow measurements at a NIR laser wavelength.
  • two of the detectors either R and B or R and G are sufficient for haemoglobin monitoring.
  • the remaining colour detector may therefore be used for speckle imaging when the wavelength of the white light source and the laser are adapted.
  • the laser wavelength can be chosen to be in the range 530 - 550 nm, where the crosstalk into the R and B detectors is small (compare with the detector sensitivity plot of Fig. 9(b)). In this embodiment no switching of the white light sources or laser is required.
  • the monitoring device sensor consists of a white, broadband LED, preferably an SMD (Surface Mount Device), and an RGB-sensor with three separate detectors each of area 1 mm x 0.3 mm. The separation of LED and detector is about 3 mm.
  • the sensor signals are amplified and input to a standard PC where variations in the signals are converted into measures of haemoglobin concentration changes.
  • a fourth detector (NIR - sensitivity) is for detecting laser radiation for blood flow monitoring based on the laser Doppler technique. For measurements of more superficial haemoglobin changes and laser Doppler blood flow the sensors can be of smaller area and positioned with smaller separations between light sources and detectors
  • ⁇ _( ⁇ ) is the mean optical path- length in the tissue, which depends on both the scattering and absorption properties and is therefore wavelength dependent.
  • overlapping spectra Eq. 1 has to be modified.
  • the measurement parameter is the intensity integrated over a wavelength range
  • the index i signifies one of the colour sensors red, green or blue (RGB) of the camera (CCD detector).
  • the sensitivity spectra of the detector are represented by D,(A) and S(k) is the normalised intensity spectrum of the light source 14.
  • F is a factor depending on optics, geometry, exposure time and other experimental conditions, which may be held constant throughout the collection of each data set.
  • G represents the amplifier gain of the CCD detector.
  • Figures 9(a), 9(b) and 9(c) show the spectral dependence of various parameters of the above equations.
  • Figure 9(a) shows the extinction spectra of oxyHb 50 and deoxyHb 52 over a wavelength range 400 nm to 700 nm.
  • Figure 9(b) shows the sensitivity spectra ⁇ ( ⁇ ), ⁇ ( ⁇ ), DR( )of the blue 54, green 56 and red 58 elements respectively of a typical RGB detector.
  • Figure 9(c) shows the spectral distribution 60 of a typical white light source S( ) (LED).
  • the amplifier gain G, of the CCD detector is set by the control software such that the intensity of the source is observed to be equal in all three colour ranges.
  • the index i represents R, G or B.
  • the assumption here is that the overlap of the spectra remains constant, and this is fulfilled as the spectra S(A) and D,(A) do not change throughout the data collection as long as the gain G, is held constant.
  • the path-length spectra h(x) need to be known. It is assumed in some prior art documents that L(x) has no wavelength dependence. A better model is obtained if, as with this invention, it is estimated for tissue from assumptions of its scattering and absorption properties.
  • Scattering coefficient ( ⁇ 3 ), anisotropy factor (g) and absorption coefficient ( ⁇ 3 ) are chosen to
  • wavelength dependence is due to the haemoglobin absorption which causes the path length to increase markedly for ⁇ > 600 nm, i.e. when the absorption is small (see Figure 9(a)).
  • Eq. 4 and 5 provide a simple tool with which to generate maps of haemoglobin changes from reflectance images.
  • Reflectance images may be straightforwardly obtained from intensity measurements relative to that taken at a reference time.
  • the reference is an arbitrary time although it may be selected, for example, as the time at which a stimulus is given to the tissue / patient.
  • This model gives a straightforward technique to analyse data obtained from three channels of an RGB detector: multiply by the inverse of matrix E to obtain the change in concentrations of the oxyHb and deoxyHb concentrations.
  • a number of assumptions have been made however in order to derive the Ey matrix and so, before this analysis can be used for diagnostic purposes, it is important to test the robustness of the model. The limitations of this approach are therefore tested below by a crosstalk analysis, an estimate of errors and finally by analysis of real data.
  • the main issue is whether attenuation changes detected at different wavelengths or wavelength bands exclude large crosstalk between the haemoglobin components.
  • true (real) changes in the concentration of one haemoglobin component affect the calculation of the other, therefore producing an erroneous result.
  • the extent of crosstalk was estimated first, from the condition number associated with the matrix inversion of the linear system of equations of Eq. 4.
  • the condition number is defined as the ratio of its largest singular value to its smallest singular value. It is an estimate of the sensitivity and likely crosstalk when measurements are contaminated by noise or errors in the experimental data.
  • C is calculated as the inverse of the condition number (cond) of E,
  • C 1/cond(E), with C limited to values between 0 and 1 .
  • a value of C close to 1 indicates a well conditioned matrix while a value close to 0 signifies that larger errors and crosstalk are likely.
  • ⁇ _( ⁇ ) path length correction
  • various regions of higher C-values appear indicating a favourable combination of wavelengths.
  • wavelengths which include ⁇ ⁇ 480 nm and ⁇ 2 ⁇ 515 nm (area 64), 560 nm (area 66) or 595 nm (area 68).
  • the third-listed combination 68 appears best with C ⁇ 0.35.
  • Using other wavelengths like ⁇ 540 nm, or 560 nm reduces C to values between 0.15 - 0.20.
  • Figures 1 1 (c) and 1 1 (d) show the results of the C calculation from matrices that include allowance for a wavelength- dependence of the mean photon path length. When this factor is included the main effect on C is a significant increase for wavelengths > 600 nm. This is further illustrated in Fig.12 where C is plotted as a function of ⁇ for four selected values of ⁇ 2 .
  • FIG 13 eight plots are shown indicating the C-values obtained from 3- wavelength systems: 3 x 2 matrices are set up using the extinction values of oxyHb and deoxyHb at three wavelengths ( ⁇ , ⁇ 2 , ⁇ 3 ). Each wavelength was stepped from 480 to 650 nm with C plotted in false colour: brighter colours indicating a higher C value.
  • Figure 13 (e) to (g) show the same maps but when the effect of path length was included in a calculation of Ey. These plots underline the importance of a careful wavelength selection when using the reduced-spectroscopic analysis provided by RGB detection. Certain combinations of wavelengths provide for well-conditioned matrix behaviour (bright areas in Figures 13(a) to (e)); other combinations do not.
  • the structure of the matrix E RGB offers the possibility that little additional spectroscopic benefit is to be gained from using both the green and blue detectors.
  • the values of the Ey elements for these detectors differ by a factor of about 2.5 (1 st and 2 nd columns above). Accordingly, the C-value is virtually unaffected when only the red and green values are used
  • FIG 15(a) shows the measured attenuation change for each channel of the camera. These values were converted into a measured concentration change for each (oxyHb and deoxyHb) haemoglobin species. For the calculation either RGB-signals, RB-signals or RG-signals were used and, as can be seen from Figure 15(b), these give comparable haemoglobin changes.
  • Figure 16(b) shows grey scale images of deoxyHb and oxyHb after cortical activation as observed with an RGB-CCD system. Graphically displayed changes at two selected points on the cortex are also shown in Figure 16(a).
  • Oxygen saturation (SO 2 ) of blood is defined as
  • the method and apparatus of this invention can accordingly be used to extract data relating to the metabolic rate of oxygen.
  • Tissue perfusion is measured by performing contrast analysis on images acquired from a CCD image sensor.
  • the analysis can be performed using either low resolution spatial processing or high resolution temporal processing.
  • spatial processing involves the analysis of the intensity variation within small groups (typically 5x5) of pixels within a single frame of image data.
  • Temporal processing involves the analysis of the intensity variation of single pixels over a number of frames (typically at least 25) of image data.
  • temporal processing is capable of producing images with high resolution at relatively low speed, whilst spatial processing produces images with reduced resolution at high speed.
  • Speckle contrast is defined as the ratio of the standard deviation ⁇ to the mean ⁇ /> of pixel intensity values within each group:
  • Equation (6) can therefore be used to relate speckle contrast K to tissue perfusion.
  • the speckle contrast can vary between 0 (no speckle, very high perfusion) and 1 (fully developed speckle, very low perfusion).
  • the speckle size at the CCD image sensor is related to the lens
  • the lens aperture is adjusted so that the speckle size is approximately equal to the image sensor pixel size.
  • Laser Doppler Blood Flow Theory and Measurements Laser light that is incident on tissue, typically the skin surface, is scattered by moving red blood cells and undergoes frequency broadening. The frequency broadened laser light, together with laser light scattered from static tissue, is detected and the resulting photocurrent processed to provide a signal that correlates with blood flow. Due to the wavelength- dependence of the optical path length of light in tissue, different
  • wavelengths can be used to provide information on flows at different depths below the tissue surface.
  • Laser light is directed to the tissue surface either via an optical fibre or as a light beam.
  • optical fibre terminates in an optical probe that can be attached to the tissue surface.
  • One or more light collecting fibres also terminate in the probe head and these fibres transmit a proportion of the scattered light to a photo detector and signal processing electronics.
  • Normal fibre separations in the probe head are a few tenths of a millimetre and consequently blood flow is measured in a tissue volume of typically 1 mm 3 or smaller.
  • single point measurements can be made by directing the laser light to the desired point on the surface.
  • the probe in a fibre optic system can be manoeuvred to tissue sites not easily accessible to a laser beam. This enables the fibre optic system to take measurements at these less accessible locations, such as in brain tissue, mouth, gut, colon, muscle and bone.
  • ⁇ weighting can also be used.
  • an ⁇ 2 weighting will give increased weight to scattering from fast moving red blood cells: ⁇ 2 weighting : Flux
  • ⁇ iand ⁇ . are lower and upper cut-off frequencies of the bandpass filter and ⁇ ( ⁇ ) is the power spectral density.
  • Digital signal processing (DSP) devices can readily perform 1024-point FFT calculations within 10 ms, which makes it possible to compute flow output directly in frequency spectrum form as described in the ⁇ and ⁇ 2 weighted algorithms.
  • Embodiments of this invention that incorporate laser Doppler flow calculations make use of a DSP device for digital processing of the power spectra of blood flow signals in order to extract a measure blood flow in real-time.
  • Noise SNxDC+DN where ni and n 2 are lower and upper limits of frequency components in the computation, p(n) is the power spectra density of the nth frequency component, DC is a measurement of the intensity of the collected scattered light, Noise is the system noise which includes dark noise (DN) and DC proportional shot noise (SN).
  • Figure 18 shows a flow chart demonstrating implementation of the above algorithms.
  • the Doppler signal AC
  • the Doppler signal AC
  • a 1024-point FFT is used.
  • data is multiplied by a twiddle cosine window table to reduce artefactual spectral content resulting from discontinuities at the start and end points of the sampled wave form, and is then converted into the frequency domain by FFT.
  • This, along with the weighting function, noise subtraction, normalisation and smoothing are all performed by the DSP.
  • the DSP starts to sample the next 1024 points of Doppler signals in order achieve a higher data rate.
  • the DSP system used in a working embodiment of this invention enables sampling and flux calculation to be performed in approximately 33 ms, resulting in a possible data rate of 30 Hz.
  • Digital signal processing of the Doppler signal as described above enables a continuous blood flow output to be produced. It is apparent that both ⁇ and ⁇ 2 weighting, or other spectral analysis algorithms, can readily be implemented without significantly altering the concept involved. Further, different frequency ranges of the Doppler signal can be analysed separately by suitable selection of the lower and upper limits of frequency components. For example, if it is known that blood flow signal for a particular application is toward a high frequency band, low frequency components can be ignored by increasing the lower limit ni to reduce the noise flow output. Another example is to calculate the ratio of flow from a high frequency band to that from a low frequency band using filtered detection. Furthermore, other parameters such as average velocity of the blood flow and red blood cell concentration can be calculated in a similar way.
  • the average Doppler frequency shift ⁇ ⁇ > of the light scattered from moving red blood cells is directly proportional to the average speed of these cells.
  • Red blood cell (rbc) concentration is proportional to the integrated power spectral density for low concentration (less than 0.5%) i.e. rbc concentration oc
  • Figure 19 illustrates apparatus suitable for extracting flux information from measurements made on skin.
  • Red or near infra-red light from a low power laser 74 is directed via an optical fibre 72 to skin tissue.
  • Light scattered back from the tissue is collected by one or more other optical fibres 72 and received by a photodetector 74.
  • the photodetector converts the optical signal into an electrical signal.
  • a bandpass filter 76 is used to remove noise outside a selected bandwidth and extract blood flow related AC components.
  • a low-pass filter 78 is also connected to the output of the photodetector 74 and is used to extract DC components, proportional to the intensity of the collected light. Outputs of the bandpass 76 and low-pass filter 78 are converted into digital form by a multiplexer and A D converter 80. Spectral analysis of the digitised Doppler signal, blood flow calculation and movement artefact detection and removal are performed by a powerful DSP device 82 in real-time.

Abstract

La présente invention concerne un appareil de mesure de paramètres sanguins tels que les chromophores, par exemple l'hémoglobine, la concentration et le débit sanguin, qui détecte la lumière dispersée depuis la surface du tissu (20) avec un détecteur multispectral (24) sensible à la lumière, à travers une plage de différentes longueurs d'onde. L'invention décrit des algorithmes qui démontrent l'extraction d'informations sur les chromophores à partir de la lumière dispersée occupant deux bandes (rouge et vert ou bleu) ou trois bandes du spectre visible. L'invention porte en outre sur l'extraction simultanée d'informations sur le débit sanguin à partir de la lumière laser dispersée occupant la même bande spectrale ou une bande distincte. Figure
PCT/GB2010/052045 2009-12-08 2010-12-08 Appareil de mesure de paramètres sanguins WO2011070357A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP10796119A EP2509491A1 (fr) 2009-12-08 2010-12-08 Appareil de mesure de paramètres sanguins
US13/514,376 US20120277559A1 (en) 2009-12-08 2010-12-08 Apparatus for Measuring Blood Parameters

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB0921477.6 2009-12-08
GBGB0921477.6A GB0921477D0 (en) 2009-12-08 2009-12-08 Apparatus for measuring blood parameters

Publications (1)

Publication Number Publication Date
WO2011070357A1 true WO2011070357A1 (fr) 2011-06-16

Family

ID=41642107

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2010/052045 WO2011070357A1 (fr) 2009-12-08 2010-12-08 Appareil de mesure de paramètres sanguins

Country Status (4)

Country Link
US (1) US20120277559A1 (fr)
EP (1) EP2509491A1 (fr)
GB (1) GB0921477D0 (fr)
WO (1) WO2011070357A1 (fr)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103083005A (zh) * 2011-11-01 2013-05-08 北京瓦力网络科技有限公司 一种心率检测的方法
WO2013158459A1 (fr) * 2012-04-18 2013-10-24 Hutchinson Technology Incorporated Dispositif de spectrométrie dans le proche infrarouge (nirs) à correction de longueur d'onde et de longueur de trajet optique
EP2837327A4 (fr) * 2012-04-13 2015-12-09 Pioneer Corp Procédé et dispositif d'évaluation d'un fluide
EP2856107A4 (fr) * 2012-06-05 2016-03-16 Hypermed Imaging Inc Procédés et appareil d'imagerie coaxiale de longueurs d'ondes multiples
CN105451640A (zh) * 2013-06-03 2016-03-30 南洋理工大学 用于足部血管再生评估的系统和方法
CN105636512A (zh) * 2013-08-14 2016-06-01 南洋理工大学 用于评估血管重建的系统和方法
US9648254B2 (en) 2014-03-21 2017-05-09 Hypermed Imaging, Inc. Compact light sensor
US9655519B2 (en) 2014-03-21 2017-05-23 Hypermed Imaging, Inc. Systems and methods for performing an imaging test under constrained conditions
WO2018006604A1 (fr) * 2016-07-02 2018-01-11 深圳市前海康启源科技有限公司 Dispositif d'imagerie des veines destiné à augmenter la définition de l'imagerie
CN107773217A (zh) * 2017-09-29 2018-03-09 天津大学 活体组织微循环代谢动态测量装置及方法
WO2018106367A1 (fr) * 2016-12-09 2018-06-14 Basil Leaf Technologies, Llc Capteurs de globules blancs et d'hémoglobine non invasifs
US10070796B2 (en) 2015-02-04 2018-09-11 General Electric Company Systems and methods for quantitative microcirculation state monitoring
EP3416366A4 (fr) * 2016-02-12 2019-02-20 Sony Corporation Appareil de capture d'image, procédé de capture d'image et système de capture d'image
US10213122B2 (en) 2012-08-15 2019-02-26 Nanyang Technological University Systems and methods for pedal revascularization assessment
CN109843154A (zh) * 2016-08-19 2019-06-04 高尔实验室有限公司 用于测量发色团浓度的改变的测量装置和设备
WO2019234428A1 (fr) 2018-06-05 2019-12-12 Moor Instruments Limited Imageur à cohérence optique
US10798310B2 (en) 2016-05-17 2020-10-06 Hypermed Imaging, Inc. Hyperspectral imager coupled with indicator molecule tracking
WO2021067451A1 (fr) * 2019-10-01 2021-04-08 University Of Washington Système et procédé d'analyse de détails de surface à l'aide d'une caméra avec espace de couleurs de basse dimension
US11050931B2 (en) 2017-05-16 2021-06-29 Sony Corporation Control device and control method
US11206990B2 (en) 2013-01-23 2021-12-28 Pedra Technology Pte Ltd Deep tissue flowmetry using diffuse speckle contrast analysis

Families Citing this family (69)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100030040A1 (en) 2008-08-04 2010-02-04 Masimo Laboratories, Inc. Multi-stream data collection system for noninvasive measurement of blood constituents
WO2010003134A2 (fr) 2008-07-03 2010-01-07 Masimo Laboratories, Inc. Protrusion, source froide thermodynamique et protection pour améliorer les mesures spectroscopiques des constituants sanguins
EP2309919B1 (fr) 2008-07-10 2019-03-06 Ecole Polytechnique Federale De Lausanne (EPFL) EPFL-TTO Imagerie optique cohérente fonctionnelle
CA2765651A1 (fr) * 2011-01-24 2012-07-24 Elizabeth Alice Munro Systeme et procede d'imagerie optique a lasers a cavite verticale a emission en surface
EP2484279A1 (fr) * 2011-02-03 2012-08-08 BIOTRONIK SE & Co. KG Capteur de débit sanguin
GB2487940B (en) * 2011-02-09 2014-12-17 Tel Hashomer Medical Res Infrastructure & Services Ltd Methods and devices suitable for imaging blood-containing tissue
US9037204B2 (en) * 2011-09-07 2015-05-19 Covidien Lp Filtered detector array for optical patient sensors
US10575737B2 (en) 2012-04-27 2020-03-03 Novadaq Technologies ULC Optical coherent imaging medical device
WO2014009859A2 (fr) 2012-07-10 2014-01-16 Aïmago S.A. Dispositif médical optique à modalités multiples pour l'évaluation de la perfusion
US9325966B2 (en) * 2012-07-30 2016-04-26 Canon Kabushiki Kaisha Depth measurement using multispectral binary coded projection and multispectral image capture
CN105190308B (zh) 2012-11-07 2021-05-28 调节成像公司 用于测量混浊样本的设备和方法
GB201317746D0 (en) 2013-10-08 2013-11-20 Smith & Nephew PH indicator
JP6596430B2 (ja) 2014-01-14 2019-10-23 ザ ジェネラル ホスピタル コーポレイション 近赤外分光法および拡散相関分光法のデバイスおよび方法
RU2691878C1 (ru) * 2014-02-05 2019-06-18 Конинклейке Филипс Н.В. Мониторинг показателей жизненно важных функций во время фототерапевтического лечения на основе камеры
JP6394367B2 (ja) * 2014-05-30 2018-09-26 ソニー株式会社 流体分析装置、流体分析方法、プログラム及び流体分析システム
US20160025620A1 (en) * 2014-07-22 2016-01-28 Olympus Corporation Optical Compositional Analysis of Mixtures
US9968285B2 (en) 2014-07-25 2018-05-15 Christie Digital Systems Usa, Inc. Multispectral medical imaging devices and methods thereof
US11553844B2 (en) * 2014-10-14 2023-01-17 East Carolina University Methods, systems and computer program products for calculating MetaKG signals for regions having multiple sets of optical characteristics
JP6813245B2 (ja) 2014-10-14 2021-01-13 イースト カロライナ ユニバーシティ 単一の画像上で解剖学的データと生理学的データとを結合するためのシステムの作動方法、コンピュータシステム、及び単一の画像上で解剖学的データと生理学的データとを結合するためのプログラムが記録された記録媒体
CA2963866C (fr) * 2014-10-14 2023-11-07 East Carolina University Procedes, systemes et produits de programme informatique pour determiner des parametres d'etat hemodynamique au moyen de signaux derives d'imagerie multispectrale de circulation e t perfusion sanguine
US20160174887A1 (en) * 2014-12-18 2016-06-23 Koninklijke Philips N.V. System and method for extracting physiological information and medical instrument for use in the system
US9931040B2 (en) 2015-01-14 2018-04-03 Verily Life Sciences Llc Applications of hyperspectral laser speckle imaging
JP6517031B2 (ja) * 2015-02-05 2019-05-22 キヤノンメディカルシステムズ株式会社 医用画像処理装置および磁気共鳴イメージング装置
US10390718B2 (en) 2015-03-20 2019-08-27 East Carolina University Multi-spectral physiologic visualization (MSPV) using laser imaging methods and systems for blood flow and perfusion imaging and quantification in an endoscopic design
US10058256B2 (en) * 2015-03-20 2018-08-28 East Carolina University Multi-spectral laser imaging (MSLI) methods and systems for blood flow and perfusion imaging and quantification
EP3291725A4 (fr) * 2015-05-07 2018-11-07 Novadaq Technologies Inc. Procédés et systèmes pour une imagerie laser à granularité de tissu à l'aide d'un capteur d'image couleur
DE102015006406A1 (de) 2015-05-19 2016-12-08 SAMTD GmbH & Co. KG Verfahren und Vorrichtung zur nicht-invasiven Bestimmung einer Messgröße eines Analyten in einem biologischen Körper
US9970955B1 (en) * 2015-05-26 2018-05-15 Verily Life Sciences Llc Methods for depth estimation in laser speckle imaging
CN105187743A (zh) * 2015-08-24 2015-12-23 北京京东方多媒体科技有限公司 健康监护电视
TWI584786B (zh) * 2015-10-01 2017-06-01 緯創資通股份有限公司 生理特徵的感測方法
WO2017112753A1 (fr) * 2015-12-22 2017-06-29 University Of Washington Dispositifs et procédés de prévision des teneurs d'hémoglobine au moyen de dispositifs électroniques tels que des téléphones mobiles
JP2017176264A (ja) * 2016-03-28 2017-10-05 富士ゼロックス株式会社 生体情報測定装置、及び生体情報測定プログラム
WO2017195038A1 (fr) 2016-05-13 2017-11-16 Smith & Nephew Plc Appareil de surveillance et de thérapie de plaie activé par un capteur
US11304634B2 (en) 2016-11-03 2022-04-19 Basil Leaf Technologies, Llc Non-invasive blood glucose sensor
US10989517B2 (en) * 2016-12-22 2021-04-27 ContinUse Biometrics Ltd. Vibration sensing system with wavelength encoding
CN106725349A (zh) * 2017-02-28 2017-05-31 武汉迅微光电技术有限公司 一种可检测血流的皮肤镜
JP6847788B2 (ja) * 2017-03-08 2021-03-24 京セラ株式会社 測定装置及び測定方法
WO2018162736A1 (fr) 2017-03-09 2018-09-13 Smith & Nephew Plc Pansement, élément de timbre et procédé de détection d'un ou plusieurs paramètres de plaie
WO2018162732A1 (fr) * 2017-03-09 2018-09-13 Smith & Nephew Plc Appareil et procédé d'imagerie du sang dans une région cible de tissu
US20180292262A1 (en) * 2017-04-06 2018-10-11 The Government Of The United States Of America, As Represented By The Secretary Of The Navy Laser speckle reduction and photo-thermal speckle spectroscopy
JP7235673B2 (ja) 2017-04-11 2023-03-08 スミス アンド ネフュー ピーエルシー センサ対応型創傷被覆材のための構成要素配置および応力緩和
US11231436B2 (en) 2017-05-02 2022-01-25 Sony Corporation Flow rate measuring method, flow rate measuring device, and program
JP7272962B2 (ja) 2017-05-15 2023-05-12 スミス アンド ネフュー ピーエルシー 創傷分析装置
CN110753512A (zh) 2017-06-23 2020-02-04 史密夫及内修公开有限公司 实施传感器的伤口监测或治疗的传感器定位
GB201804502D0 (en) 2018-03-21 2018-05-02 Smith & Nephew Biocompatible encapsulation and component stress relief for sensor enabled negative pressure wound therapy dressings
GB201809007D0 (en) 2018-06-01 2018-07-18 Smith & Nephew Restriction of sensor-monitored region for sensor-enabled wound dressings
EP3664859A2 (fr) 2017-08-10 2020-06-17 Smith & Nephew plc Positionnement de capteurs pour la surveillance ou le traitement des plaies activé(e) par capteurs
GB201804971D0 (en) 2018-03-28 2018-05-09 Smith & Nephew Electrostatic discharge protection for sensors in wound therapy
GB201718870D0 (en) 2017-11-15 2017-12-27 Smith & Nephew Inc Sensor enabled wound therapy dressings and systems
US11759144B2 (en) 2017-09-10 2023-09-19 Smith & Nephew Plc Systems and methods for inspection of encapsulation and components in sensor equipped wound dressings
GB201718859D0 (en) 2017-11-15 2017-12-27 Smith & Nephew Sensor positioning for sensor enabled wound therapy dressings and systems
US11596553B2 (en) 2017-09-27 2023-03-07 Smith & Nephew Plc Ph sensing for sensor enabled negative pressure wound monitoring and therapy apparatuses
EP3687396A1 (fr) 2017-09-28 2020-08-05 Smith & Nephew plc Neurostimulation et surveillance à l'aide d'un appareil de surveillance et de traitement de plaie activé par un capteur
US11559438B2 (en) 2017-11-15 2023-01-24 Smith & Nephew Plc Integrated sensor enabled wound monitoring and/or therapy dressings and systems
JP2021526907A (ja) * 2018-06-08 2021-10-11 イースト カロライナ ユニバーシティ マルチスペクトルレーザ撮像（ＭＳＬＩ）方法及びシステムを使用した末梢血酸素飽和度（ＳｐＯ２）及びヘモグロビン濃度の決定
BR112021000708A2 (pt) 2018-07-16 2021-04-20 Bbi Medical Innovations, Llc medição de perfusão e oxigenação
GB2592508B (en) 2018-09-12 2022-08-31 Smith & Nephew Device, apparatus and method of determining skin perfusion pressure
GB201815691D0 (en) * 2018-09-26 2018-11-07 Univ Oxford Innovation Ltd Characterisation of thrombus
CN109363768A (zh) * 2018-10-10 2019-02-22 南京诺源医疗器械有限公司 785nm波长光源近红外荧光造影手术引导系统
CN109791694B (zh) * 2018-12-05 2023-06-30 京东方科技集团股份有限公司 用于确定对象的生理参数的方法和设备及其计算机程序产品
GB201820927D0 (en) 2018-12-21 2019-02-06 Smith & Nephew Wound therapy systems and methods with supercapacitors
CA3134066A1 (fr) 2019-03-26 2020-10-01 East Carolina University Imagerie par fluorescence proche infrarouge pour la visualisation de l'irrigation et du debit sanguins, ainsi que systemes et produits programmes d'ordinateur associes
CN110292373A (zh) * 2019-07-23 2019-10-01 优谱激光科技(南京)有限公司 一种高性能人体组织血流检测分析装置
US11759116B2 (en) * 2019-12-16 2023-09-19 Covidien Ag Determining blood flow using laser speckle imaging
CN112858196A (zh) * 2020-10-20 2021-05-28 重庆大学 一种三波长静脉血氧浓度测量的方法
WO2023113809A1 (fr) * 2021-12-16 2023-06-22 National Health Research Institutes Système d'imagerie de contraste à granularité laser et procédé d'imagerie de contraste à granularité laser associé
CN115251853A (zh) * 2022-07-26 2022-11-01 中国科学院深圳先进技术研究院 一种微血管的位置检测方法、装置、系统及存储介质
CN116236164B (zh) * 2022-12-20 2023-12-08 哈尔滨海鸿基业科技发展有限公司 一种血运重建实时评估装置
CN116337803B (zh) * 2023-01-10 2024-01-02 中南民族大学 一种液体样本成分检测探头、加工方法及检测系统

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4596254A (en) 1984-12-18 1986-06-24 Tsi Research Associates Limited Partnership Laser Doppler flow monitor
US5187572A (en) * 1990-10-31 1993-02-16 Olympus Optical Co., Ltd. Endoscope system with a plurality of synchronized light source apparatuses
EP0949880A1 (fr) 1996-11-09 1999-10-20 Moor Instruments Limited Appareil de mesure du debit sanguin microvasculaire
US5982497A (en) * 1998-07-09 1999-11-09 Optical Insights, Llc Multi-spectral two-dimensional imaging spectrometer
WO2003077749A2 (fr) * 2002-03-12 2003-09-25 Beth Israel Deaconess Medical Center Systemes d'imagerie medicale
US6859658B1 (en) * 1998-11-18 2005-02-22 Lea Medizintechnik Gmbh Device for non-invasively detecting the oxygen metabolism in tissues
US20050167621A1 (en) * 2000-12-19 2005-08-04 Haishan Zeng Imaging methods for fluorescence and reflectance imaging and spectroscopy and for contemporaneous measurements of electromagnetic radiation with multiple measuring devices
US20070024946A1 (en) 2004-12-28 2007-02-01 Panasyuk Svetlana V Hyperspectral/multispectral imaging in determination, assessment and monitoring of systemic physiology and shock
WO2009005748A1 (fr) * 2007-06-29 2009-01-08 The Trustees Of Columbia University In The City Ofnew York Systèmes et procédés d'imagerie optique ou de spectroscopie
US20090287076A1 (en) * 2007-12-18 2009-11-19 Boyden Edward S System, devices, and methods for detecting occlusions in a biological subject

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7113817B1 (en) * 2001-10-04 2006-09-26 Wintec, Llc Optical imaging of blood circulation velocities
US8082015B2 (en) * 2004-04-13 2011-12-20 The Trustees Of The University Of Pennsylvania Optical measurement of tissue blood flow, hemodynamics and oxygenation
AU2005280762A1 (en) * 2004-06-30 2006-03-09 University Of Rochester Photodynamic therapy with spatially resolved dual spectroscopic monitoring
GB0718291D0 (en) * 2007-09-19 2007-10-31 King S College London Imaging apparatus and method
US8849380B2 (en) * 2007-11-26 2014-09-30 Canfield Scientific Inc. Multi-spectral tissue imaging

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4596254A (en) 1984-12-18 1986-06-24 Tsi Research Associates Limited Partnership Laser Doppler flow monitor
US5187572A (en) * 1990-10-31 1993-02-16 Olympus Optical Co., Ltd. Endoscope system with a plurality of synchronized light source apparatuses
EP0949880A1 (fr) 1996-11-09 1999-10-20 Moor Instruments Limited Appareil de mesure du debit sanguin microvasculaire
US5982497A (en) * 1998-07-09 1999-11-09 Optical Insights, Llc Multi-spectral two-dimensional imaging spectrometer
US6859658B1 (en) * 1998-11-18 2005-02-22 Lea Medizintechnik Gmbh Device for non-invasively detecting the oxygen metabolism in tissues
US20050167621A1 (en) * 2000-12-19 2005-08-04 Haishan Zeng Imaging methods for fluorescence and reflectance imaging and spectroscopy and for contemporaneous measurements of electromagnetic radiation with multiple measuring devices
WO2003077749A2 (fr) * 2002-03-12 2003-09-25 Beth Israel Deaconess Medical Center Systemes d'imagerie medicale
US20070024946A1 (en) 2004-12-28 2007-02-01 Panasyuk Svetlana V Hyperspectral/multispectral imaging in determination, assessment and monitoring of systemic physiology and shock
WO2009005748A1 (fr) * 2007-06-29 2009-01-08 The Trustees Of Columbia University In The City Ofnew York Systèmes et procédés d'imagerie optique ou de spectroscopie
US20090287076A1 (en) * 2007-12-18 2009-11-19 Boyden Edward S System, devices, and methods for detecting occlusions in a biological subject

Non-Patent Citations (14)

* Cited by examiner, † Cited by third party
Title
ANDREW K DUNN ET AL: "Simultaneous imaging of total cerebral hemoglobinconcentration, oxygenation, andblood flow during functional activation", OPTICS LETTERS, OSA, OPTICAL SOCIETY OF AMERICA, WASHINGTON, DC, US, vol. 28, no. 1, 1 January 2003 (2003-01-01), pages 28, XP009123641, ISSN: 0146-9592, DOI: 10.1364/OL.28.000028 *
DUNN ET AL.: "Simultaneous imaging of total cerebral haemoglobin concentration, oxygenation, and blood flow during functional activation", OPTICS LETTERS, vol. 28, 2003, pages 1
ELIZABETH M. C. HILLMAN: "Optical brain imaging in vivo: techniquesand applications from animal to man", JOURNAL OF BIOMEDICAL OPTICS, vol. 12, no. 5, 1 November 2007 (2007-11-01), online, XP002622876, Retrieved from the Internet <URL:http://scitation.aip.org/getpdf/servlet/GetPDFServlet?filetype=pdf&id=JBOPFO000012000005051402000001&idtype=cvips&doi=10.1117/1.2789693&prog=normal> [retrieved on 20110215], DOI: 10.1117/1.2789693 *
ELIZABETH M. C. HILLMAN; ANNA DEVOR; MATTHEW BOUCHARD; ANDREW K. DUNN; GW KRAUSS; JESSE SKOCH; BRIAN J. BACSKAI; ANDERS M. DALE; D: "Depth-resolved Optical Imaging and Microscopy of Vascular Compartment Dynamics During Somatosensory Stimulation", NEUROIMAGE, vol. 35, no. 1, March 2007 (2007-03-01), pages 89 - 104
IZUMI NISHIDATE ET AL.: "Visualizing of skin chromophore concentration by use of RGB images", OPTICS LETTERS, vol. 33, no. 19, 2008, pages 2263 - 2265
J.D.BRIERS: "Laser Speckle contrast imaging for measuring blood flow", OPTICA APPLICATA, vol. XXXVII, no. 1-2, 2007, pages 139 - 152
J.D.BRIERS; A.F.FLETCHER, REPORTS,INVEST.OPHTHALMOL.VIS.SCI., vol. 22, no. 2, February 1982 (1982-02-01), pages 255 - 259
KOHL-BAREIS M ET AL: "System for the measurement of blood flow and oxygenation in tissue applied to neurovascular coupling in brain", PHOTON MIGRATION AND DIFFUSE-LIGHT IMAGING II, vol. 5859, no. 1, 58590F, 12 June 2005 (2005-06-12), Proceedings of the SPIE - The International Society for Optical Engineering SPIE-Int. Soc. Opt. Eng. USA, pages 1 - 7, XP002622874, ISSN: 0277-786X, DOI: 10.1117/12.632835 *
KOICHIRO SAKAGUCHI; TOMOYA TACHIBANA; SHUNSUKE FURUKAWA; TAKUSHIGE KATSURA; KYOKO YAMAZAKI; HIDEO KAWAGUCHI; ATSUSHI MAKI; EIJI OK: "Experimental prediction of the wavelength-dependent path-length factor for optical intrinsic signal analysis", APPLIED OPTICS, vol. 46, no. 14, 2007, pages 2769 - 2777
MATTHEW B. BOUCHARD*, BRENDA R. CHEN*, SEAN A. BURGESS, ELIZABETH M. C. HILLMAN: "Ultra-fast multispectral optical imaging ofcortical oxygenation, blood flow, andintracellular calcium dynamics", OPTICS EXPRESS, vol. 17, no. 18, 20 August 2009 (2009-08-20), pages 15670 - 15678, XP002622877, Retrieved from the Internet <URL:http://www.opticsinfobase.org/view_article.cfm?gotourl=http%3A%2F%2Fwww.opticsinfobase.org%2FDirectPDFAccess%2FCC38AB38-CC94-21E5-04DB355890C3D75A_185149.pdf%3Fda%3D1%26id%3D185149%26seq%3D0%26mobile%3Dno&org=> [retrieved on 20110215], DOI: 10.1364/OE.17.015670 *
MAYHEW J ET AL.: "Increased Oxygen Consumption Following Activation of Brain: Theoretical Footnotes Using Spectroscopic Data from Barrel Cortex", NEUROIMAGE, vol. 13, 2001, pages 975 - 987
NEAL PRAKASH; JONATHAN D. BIAG; SAMEER A. SHETH; SATOSHI MITSUYAMA; JEREMY THERIOT; CHAITHANYA RAMACHANDRA; ARTHUR W. TOGA: "Temporal profiles and 2-dimensional oxy-, deoxy-, and total-hemoglobin somatosensory maps in rat versus mouse cortex", NEUROIMAGE, vol. 37, no. 1, 2007, pages S27 - S36
PHILL B. JONES, HWA KYOUNG SHIN, DAVID A. BOAS, BRADLEY T. HYMAN, MICHAEL A. MOSKOWITZ, CENK AYATA, ANDREW K. DUNN: "Simultaneous multispectral reflectance imaging and laser speckle flowmetry of cerebral blood flow and oxygen metabolism in focal cerebral ischemia", JOURNAL OF BIOMEDICAL OPTICS, vol. 13, no. 4, 044007, 24 July 2008 (2008-07-24), online, XP002622875, Retrieved from the Internet <URL:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2790046/pdf/nihms154698.pdf> [retrieved on 20110216], DOI: 10.1117/1.2950312 *
See also references of EP2509491A1

Cited By (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103083005A (zh) * 2011-11-01 2013-05-08 北京瓦力网络科技有限公司 一种心率检测的方法
EP2837327A4 (fr) * 2012-04-13 2015-12-09 Pioneer Corp Procédé et dispositif d'évaluation d'un fluide
US11045122B2 (en) 2012-04-18 2021-06-29 Fortiori Design Llc NIRS device with optical wavelength and path length correction
WO2013158459A1 (fr) * 2012-04-18 2013-10-24 Hutchinson Technology Incorporated Dispositif de spectrométrie dans le proche infrarouge (nirs) à correction de longueur d'onde et de longueur de trajet optique
US9907494B2 (en) 2012-04-18 2018-03-06 Hutchinson Technology Incorporated NIRS device with optical wavelength and path length correction
EP2856107A4 (fr) * 2012-06-05 2016-03-16 Hypermed Imaging Inc Procédés et appareil d'imagerie coaxiale de longueurs d'ondes multiples
US9354115B2 (en) 2012-06-05 2016-05-31 Hypermed Imaging, Inc. Methods and apparatus for coaxial imaging of multiple wavelengths
US10448836B2 (en) 2012-06-05 2019-10-22 Hypermed Imaging, Inc. Methods and apparatus for coaxial imaging of multiple wavelengths
US10213122B2 (en) 2012-08-15 2019-02-26 Nanyang Technological University Systems and methods for pedal revascularization assessment
US11206990B2 (en) 2013-01-23 2021-12-28 Pedra Technology Pte Ltd Deep tissue flowmetry using diffuse speckle contrast analysis
EP3003126A4 (fr) * 2013-06-03 2017-03-22 Nanyang Technological University Systèmes et procédés pour évaluation de revascularisation du pied
CN105451640A (zh) * 2013-06-03 2016-03-30 南洋理工大学 用于足部血管再生评估的系统和方法
CN105636512A (zh) * 2013-08-14 2016-06-01 南洋理工大学 用于评估血管重建的系统和方法
US10205892B2 (en) 2014-03-21 2019-02-12 Hypermed Imaging, Inc. Compact light sensor
US11399716B2 (en) 2014-03-21 2022-08-02 Hypermed Imaging, Inc. Systems and methods for performing an imaging test under constrained conditions
US9648254B2 (en) 2014-03-21 2017-05-09 Hypermed Imaging, Inc. Compact light sensor
US11159750B2 (en) 2014-03-21 2021-10-26 Hypermed Imaging, Inc. Compact light sensor
US9746377B2 (en) 2014-03-21 2017-08-29 Hypermed Imaging, Inc. Compact light sensor
US9655519B2 (en) 2014-03-21 2017-05-23 Hypermed Imaging, Inc. Systems and methods for performing an imaging test under constrained conditions
US10652481B2 (en) 2014-03-21 2020-05-12 Hypermed Imaging, Inc. Compact light sensor
US10070796B2 (en) 2015-02-04 2018-09-11 General Electric Company Systems and methods for quantitative microcirculation state monitoring
EP3416366A4 (fr) * 2016-02-12 2019-02-20 Sony Corporation Appareil de capture d'image, procédé de capture d'image et système de capture d'image
US10798310B2 (en) 2016-05-17 2020-10-06 Hypermed Imaging, Inc. Hyperspectral imager coupled with indicator molecule tracking
WO2018006604A1 (fr) * 2016-07-02 2018-01-11 深圳市前海康启源科技有限公司 Dispositif d'imagerie des veines destiné à augmenter la définition de l'imagerie
CN109843154A (zh) * 2016-08-19 2019-06-04 高尔实验室有限公司 用于测量发色团浓度的改变的测量装置和设备
CN109843154B (zh) * 2016-08-19 2023-03-24 高尔实验室有限公司 用于测量发色团浓度的改变的测量装置和设备
WO2018106367A1 (fr) * 2016-12-09 2018-06-14 Basil Leaf Technologies, Llc Capteurs de globules blancs et d'hémoglobine non invasifs
US11050931B2 (en) 2017-05-16 2021-06-29 Sony Corporation Control device and control method
CN107773217B (zh) * 2017-09-29 2021-01-05 天津大学 活体组织微循环代谢动态测量装置及方法
CN107773217A (zh) * 2017-09-29 2018-03-09 天津大学 活体组织微循环代谢动态测量装置及方法
WO2019234428A1 (fr) 2018-06-05 2019-12-12 Moor Instruments Limited Imageur à cohérence optique
WO2021067451A1 (fr) * 2019-10-01 2021-04-08 University Of Washington Système et procédé d'analyse de détails de surface à l'aide d'une caméra avec espace de couleurs de basse dimension

Also Published As

Publication number Publication date
US20120277559A1 (en) 2012-11-01
EP2509491A1 (fr) 2012-10-17
GB0921477D0 (en) 2010-01-20

Similar Documents

Publication Publication Date Title
US20120277559A1 (en) Apparatus for Measuring Blood Parameters
US11330985B2 (en) Near-infrared optical imaging system for hemodynamic imaging, pulse monitoring, and mapping spatio-temporal features
RU2562886C2 (ru) Устройство и способ для определения и мониторинга компонентов или свойств измеряемой среды, в частности значений физиологических показателей крови
Eriksson et al. Non-invasive imaging of microcirculation: a technology review
Humphreys et al. Noncontact simultaneous dual wavelength photoplethysmography: a further step toward noncontact pulse oximetry
US9504394B2 (en) Electro-optical system, apparatus, and method for ambulatory monitoring
JP3619969B2 (ja) 複数光源を備えた光センサー
US20180070830A1 (en) Systems and methods for time-resolved diffuse correlation spectroscopy
CN105473060B (zh) 用于从远程检测到的电磁辐射中提取生理信息的系统和方法
US20030139667A1 (en) Tissue viability/health monitor utilizing near infrared spectroscopy
JP2007528276A (ja) 水による近赤外吸収を用いたパルス酸素濃度計のモーションアーチファクト除去
Ewerlöf et al. Estimation of skin microcirculatory hemoglobin oxygen saturation and red blood cell tissue fraction using a multispectral snapshot imaging system: a validation study
US20200294228A1 (en) Non-Contact Multispectral Imaging for Blood Oxygen Level and Perfusion Measurement and Related Systems and Computer Program Products
EP3125745A1 (fr) Dispositif, système et procédé de détection et/ou de monitorage d&#39;une tumeur
JP7051083B2 (ja) 心理状態判定方法、判定装置、判定システムおよび判定プログラム
WO2019161336A1 (fr) Système et procédé pour une mesure optique de débit sanguin
Välisuo Optical methods for assessing skin flap survival
Cysewska-Sobusiak Examples of acquisition and application of biooptical signals
Cancio et al. Visible hyperspectral imaging: monitoring the systemic effects of shock and resuscitation
Rajaram et al. Hybrid broadband NIRS/Diffuse correlation spectroscopy system for simultaneous monitoring of cerebral perfusion and cytochrome c oxidase
Tang et al. Brain Activity Monitoring System Based on EEG-NIRS Measurement System
Cysewska-Sobusiak et al. Examples of transillumination techniques used in medical measurements and imaging
Bachir Diffuse transmittance visible spectroscopy using smartphone flashlight for photoplethysmography and vital signs measurements
Arimoto Measurement of 2-D SpO2 distribution in skin tissue by multispectral imaging with depth selectivity control
Fantini et al. Monitoring brain activity using near-infrared light

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10796119

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 2010796119

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 13514376

Country of ref document: US