WO2013104760A1 - Diaphanoscope à balayage sans contact - Google Patents

Diaphanoscope à balayage sans contact Download PDF

Info

Publication number
WO2013104760A1
WO2013104760A1 PCT/EP2013/050496 EP2013050496W WO2013104760A1 WO 2013104760 A1 WO2013104760 A1 WO 2013104760A1 EP 2013050496 W EP2013050496 W EP 2013050496W WO 2013104760 A1 WO2013104760 A1 WO 2013104760A1
Authority
WO
WIPO (PCT)
Prior art keywords
illumination
tissue sample
coordinate
image
associated tissue
Prior art date
Application number
PCT/EP2013/050496
Other languages
English (en)
Inventor
Béat HORISBERGER
Mathieu GILLIÉRON
Didier Maillefer
Original Assignee
Centre Hospitalier Universitaire Vaudois (Chuv)
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 Centre Hospitalier Universitaire Vaudois (Chuv) filed Critical Centre Hospitalier Universitaire Vaudois (Chuv)
Publication of WO2013104760A1 publication Critical patent/WO2013104760A1/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
    • A61B5/0059—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence
    • A61B5/0062—Arrangements for scanning
    • A61B5/0064—Body surface scanning
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/0059—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence
    • A61B5/0077—Devices for viewing the surface of the body, e.g. camera, magnifying lens
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/44—Detecting, measuring or recording for evaluating the integumentary system, e.g. skin, hair or nails
    • A61B5/441—Skin evaluation, e.g. for skin disorder diagnosis
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B2576/00—Medical imaging apparatus involving image processing or analysis
    • A61B2576/02—Medical imaging apparatus involving image processing or analysis specially adapted for a particular organ or body part
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/74—Details of notification to user or communication with user or patient ; user input means
    • A61B5/742—Details of notification to user or communication with user or patient ; user input means using visual displays
    • A61B5/7425—Displaying combinations of multiple images regardless of image source, e.g. displaying a reference anatomical image with a live image
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/74—Details of notification to user or communication with user or patient ; user input means
    • A61B5/742—Details of notification to user or communication with user or patient ; user input means using visual displays
    • A61B5/743—Displaying an image simultaneously with additional graphical information, e.g. symbols, charts, function plots
    • G—PHYSICS
    • G16—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR SPECIFIC APPLICATION FIELDS
    • G16H—HEALTHCARE INFORMATICS, i.e. INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR THE HANDLING OR PROCESSING OF MEDICAL OR HEALTHCARE DATA
    • G16H30/00—ICT specially adapted for the handling or processing of medical images
    • G16H30/40—ICT specially adapted for the handling or processing of medical images for processing medical images, e.g. editing

Definitions

  • the present invention relates to diaphanoscopes and in particular to scanning non-contact diaphanoscopes.
  • tissue samples such as determine ecchymosis which may or may not be visible to the naked eye.
  • the reference EP1891891A1 discloses a diaphanoscope which has a laying unit to lay an annular light source i.e. LED, in contact with the skin.
  • a light analysis unit i.e. color camera, analyzes the light transmitted through the skin. The light is placed at an end of a hollow cylindrical element, and another end of the element is fixed to the color camera. The camera is connected to a computerized
  • an associated tissue sample such as associated tissue samples, such as subcutaneous tissues, such as mucous membranes, such as other types of samples including amorph solids and fluids
  • the system comprising
  • a light source arranged for providing localized illumination light
  • the surface of the associated tissue sample defining a coordinate system, so as to provide localized illumination of an illumination region, a position of the illumination region being centered at an illumination coordinate,
  • - scanning means arranged for providing localized illumination of spatially different illumination regions each having positions being centered at respective illumination coordinates
  • a camera arranged for capturing a set of first images, by providing for each illumination coordinate a first image of the associated tissue sample, where the field of view of the first image comprising a region of interest surrounding the corresponding illumination region,
  • an operating system arranged for controlling the scanning means and the camera so as to obtain each of the first images of the set of first images during illumination of the corresponding illumination region, wherein each of the regions of interest for an illumination coordinate being overlapping with at least one other region of interest for a different illumination coordinate, and
  • illumination coordinate a decay value being representative of a change in a level of brightness within the subregion of interest with respect to a distance from the illumination coordinate
  • the invention is particularly, but not exclusively, advantageous for obtaining a reconstruction image of the associated tissue sample by employing non-contact imaging means. Another advantage may be that it enables gathering quantitative data.
  • the basic principle of the system may be described as probing the
  • associated tissue sample at a number of positions, by illuminating a part of the associated tissue (such as skin), and assigning decay values to surrounding regions, where the decay values may subsequently be used for reconstructing an image of the associated tissue (such as skin), which image reveals information regarding about structures in the associated tissue sample.
  • An advantage of the system is that it allows detecting ecchymosis within the associated tissue sample. Another advantage may be that it works on various kinds of associated tissue sample, such as various skin types spanning light to dark pigmentation. Another advantage may be that the associated sample can be planar or non-planar, such as dish or curve (such as would typically be the case for a finger). Another advantage is that it may be transportable. Another advantage may be that the associated tissue sample need not be moved during examination.
  • Another potential advantage is that it is easy to use. Another potential advantage is that it may be fast. Another possible advantage is that it is non-invasive. Another possible advantage is that the examination can be performed in any environment. Another potential advantage is that since it employs non-contact measurement, the data will not suffer from pressure induced artefacts, the system may be more hygienic in use, the system may be better suited for measurements on certain sensitive areas such as abrasions, skin wounds, and/or mucosal membranes (such as for example in the mouth or genital areas) . Another advantage may be that the resolution achieved can be very good, such as better than 1 mm .
  • the invention may be useful for providing a forensic method and a setup for the detection of ecchymoses, such as for the detection of bruises, such as for the detection of hematomas (in this application, 'bruises' and 'hematomas' may be referred to interchangeably with 'ecchymoses') which are difficult to detect by direct visual inspection.
  • ecchymoses such as for the detection of bruises
  • hematomas in this application, 'bruises' and 'hematomas' may be referred to interchangeably with 'ecchymoses'
  • the same principle is also applicable to a variety of medical diagnosis applications (investigation of inflammation) as well as paramedical such as biometry. As such, it can be considered as a novel medical imaging modality.
  • non-medical applications such as in the food or powder industries.
  • the method is based on diaphanoscopy, which consists in the analysis of the light backscattered by the tissues locally illuminated .
  • we use a collimated laser beam for the illumination and a CCD camera to collect the image of the scattered halo.
  • This setup allows for a completely contactless investigation method . Differences of light absorption reveal the nature of the different subcutaneous tissues.
  • immobilized blood such as in an ecchymose is revealed by contrast with the surrounding fatty tissues.
  • the laser and the camera are scanned over the pre-defined body surface, the multiple images of the light halo are analysed and a composite image is reconstructed, revealing the light absorbing nature of the underlying tissues.
  • the system reveals the detail of the normal superficial venous system as well as potential abnormal accumulations of blood such as ecchymoses
  • the reconstruction image provided in the end of the procedure comprises information on the potentiality of an ecchymoses present in the scanned associated tissue sample, such as skin zone, such as by a dark zone in a greyscale image. It is noted that interpretation of the image zone remains the responsibility of the medical doctor or the health professional in charge. In this regard, the method and the apparatus must be considered as a medical imaging modality rather than a diagnostic device. The system need not be operated or used by a medical practitioner and thus does not require involvement of a medical practitioner.
  • 'reconstruction image' is understood an image which is composed by a plurality of regions, such as pixels, and the color and/or brightness of each region in the reconstruction image is based on information gained in an indirect manner, such as the color and/or brightness of each region being based on multiple images or photographs, such as being based on calculations of data obtained via spatially resolved measurements on the associated tissue sample.
  • the 'associated tissue sample' may in particular embodiments be skin, such as human skin, such as animal skin.
  • the associated tissue sample may in particular embodiments be mucous membranes of a human or an animal.
  • Light source' is to be understood to be any light source capable of providing light which may be directed to the associated tissue sample and be confined spatially to a sufficiently small spot, such as an illumination region, which is sufficiently bright to enable measuring a decay of backscattered light with respect to distance from the illumination region.
  • the light source is a LASER. It is understood that the light source may be capable of providing a light beam.
  • the 'Illumination region' is understood to be the area illuminated by the light source.
  • the illumination region may be centered at the spot of a LASER.
  • the extent of the illuminated area may be defined as the area where the light intensity is above half of the maximum light intensity of the light intensity.
  • the extent of the illumination region may be defined as a region in the first image comprising the illuminated area and wherein the pixels of the first image are saturated.
  • the "illumination coordinate" is defined as the center of the illumination region.
  • the center of the illumination region may be determined by identifying the illumination region by determination of the center of gravity of the illuminated area (which is a well-defined, known mathematical procedure method, which will be known by the skilled person). However, the determination of the center may also be carried out using alternative methods, such as fitting an ellipse and determining the two axes and the center.
  • 'Scanning means' is understood to be a scanner enabled to spatially move the associated tissue sample relative to the light beam, so as to enable illuminating spatially different 'illumination regions'.
  • the scanning means is embodied by physically moving the light source, such as by moving or rotating the light source.
  • the scanning means is embodied by moving the light beam, such as using one or more movable mirrors.
  • An advantage of moving the light beam may be that it enables that the light source and the associated tissue sample are kept stationary, and moving, e.g., a mirror may be faster, require less power, and the possibly fragile light source may be kept stationary.
  • the scanning means could also be arranged for moving the associated tissue sample.
  • the scanning means may be realized by a number of measures know to the skilled person, such as an X-Y-table whereupon the light source and camera are placed, means for rotating a light source around one or more axis, a plurality of X-Y-tables and/or movable and/or rotatable mirrors or any combination thereof.
  • the scanning may be realized by rectilinear translation along two orthogonal axes (X-Y table) and/or rotation around two orthogonal axes (such as by means of a pan-tilt unit).
  • X-Y-tables are known in the art and understood to enable controlled motion in two dimensions.
  • a 'camera' is known within the art, and is understood to be a device which is capable of obtaining images, i.e., spatially resolved information from an object, such as an associated tissue sample, such as obtaining at a point in time an image of an object.
  • the camera comprises imaging optics, such as one or more lenses, allowing obtaining an image of an associated tissue sample being placed at a distance with respect to the camera, such as at a distance of at least 10 cm, such as at least 20 cm, such as at least 50 cm, such as at least 100 cm.
  • the camera may work within certain wavelength regions of the electromagnetic spectrum, such as within the visible spectrum and/or the near infrared (NIR) spectrum, such as within a narrow region, such as being a color or monochrome camera.
  • a range finding instrument such as a laser, is used for determining the distance from the camera to the associated tissue sample.
  • 'field of view is understood the region on the associated tissue sample from which the camera is able to obtain information. It is understood that the field of view may change as a result of the position or orientation of the camera with respect to the associated tissue sample and/or the settings of the camera.
  • the field of view of the first image comprising a region of interest surrounding the corresponding illumination region' is understood, that the field of view at least partially encloses the corresponding illumination region, such as the field of view comprising a region adjacent to the illumination region and partially enclosing the illumination region.
  • the field of view comprises a region surrounding the illumination region, such as comprising a region spanning at least 90 degrees around the illumination region, such as comprising a region spanning at least 180 degrees around the illumination region, such as comprising a region spanning at least 270 degrees around the illumination region, such as comprising a region spanning substantially 360 degrees, such as 360 degrees, around the illumination region.
  • the field of view comprises a region surrounding the illumination region, such as completely enclosing the illumination region, such as completely enclosing 360 degrees around the illumination region.
  • 'Region of interest' is understood to be a region on the associated tissue sample which - during illumination of the illumination region - emits backscattered light so that a 'decay value' representative of a decay of the brightness of the
  • backscattered light (with respect to a distance from the illumination coordinate) within the region of interest may be obtained by measurement of a plurality of brightness values at a plurality of radially separated positions with respect to the illumination coordinate within the region of interest.
  • the subregions may in particular embodiments correspond to regions within the region of interest which are comprised within a certain angular span, such as the angular span being defined in a polar coordinate system where the center coordinate coincides with the illumination coordinate.
  • each subregions may in such embodiment be confined to be within a slice of a certain angular width, such as 0.01 degree, 0.1 degree, such as 0.5 degree, such as 1 degree, such as 2 degree, such as 3 degree, such as 4 degree, such as 5 degree, such as 6 degree, such as 10 degree, such as 20 degree, such as 30 degree, such as 50 degree, such as 60 degree, such as 90 degree, such as 120 degree, such as 180 degree.
  • the 'decay value' is representative of a change in a level of brightness within the subregion of interest with respect to a distance from the illumination coordinate, and may be understood to be representative of a decay of backscattered light with respect to distance from the illumination region, where the backscattered light is light, such as a photon, which was initially emitted from the light source, entered into the associated tissue sample at the illumination region, traversed a distance through the associated tissue sample, such as via diffusion, and was emitted from the associated tissue sample through the region of interest and collected by the camera.
  • the decay value information may thus be obtained which reflects the internal structure and composition of the associated tissue sample, in particular if the internal structure and composition affects how photons travel within the associated tissue sample.
  • the determination of the subregions of interest may be done according to predetermined values, such as by subdividing a region of interest surrounding the illumination region into 180 regions which each spans 2 degrees around the illumination region.
  • the processor may be arranged for observing variations in decay value within the region of interest so as to subdivide to a finer extent if variations are large, a subdivide to a lesser extent if the variations are small.
  • the 'operating system' may be embodied by a unit comprising a processor, such as a computer, such as a standard personal computer.
  • a system wherein the processor further being arranged for receiving a set of scanning coordinates corresponding to the illumination coordinates, where the set of scanning coordinates define a position of the scanning means for each illumination coordinate and wherein the processor further being arranged for determining the positions of the illumination regions with respect to the associated tissue sample based on the scanning coordinates.
  • the 'scanning coordinates' are understood to be the spatial coordinates which the operation system sends to the scanning means in order to allow the scanning means to scan across the associated tissue sample.
  • the spatial relationship between the first images and the associated tissue sample may be realized by the processor via the scanning coordinates.
  • a system wherein the scanning means are arranged for controlling the field of view of the camera with respect to the associated tissue sample.
  • the field of view may be moved in response to the position of the illumination region and the region of interest, and this may in turn enable the field of view to be relatively small, which in turn may enable the resolution of the region of interest to be relatively high.
  • the scanning means is arranged for moving and/or orienting the camera together with the light source.
  • the camera is fixed with respect to the associated tissue sample. An advantage of this may be that the camera, which may be heavy and fragile, need not be moved. Another advantage may be that the image analysis may be kept relatively simple, since the field of view of each image may correspond to the same region on the associated tissue sample.
  • a system wherein the operating system further being arranged for obtaining for each illumination region a second image, where the first image and the second image differ from each other in exposure time and/or size of aperture of the camera.
  • An advantage of this embodiment may be that the first and second image may be obtained under different camera settings, so as to obtain a first image which is optimized for determining the decay value, such as having optimized contrast in the region of interest, and furthermore so as to obtain a second image enabling determining the illumination region with optimal precision, such as by having a second image which is obtained with small aperture of the camera and/or short exposure time, wherein only the illumination region is visible enabling a precise determination of the position of illumination coordinate.
  • the first and second images need not be obtained in a particular sequence.
  • the processor being arranged for determining the position of the illumination coordinate in a
  • Deviation may be due to the surface of the associated tissue sample being non-planar and/or the surface of the associated tissue sample being slightly misaligned with respect to the camera and light source, such as the surface normal of the surface of the associated tissue sample not being
  • a system wherein the processor further being arranged for determining the position of each illumination region with respect to the associated tissue sample is based on one or more images of the associated tissue sample obtained during illumination of the corresponding illumination region .
  • the spatial relationship between the first images and the associated tissue sample may be made via images (for example, for a fixed camera of high resolution, the position could be determined directly in absolute coordinates from the first image) .
  • a further set of images such as images of the associated tissue sample having a larger field of view, may enable determining the position of the illumination region with respect to the associated tissue sample.
  • a system wherein the processor further being arranged for excluding from the region of interest for each first image one or more regions wherein the brightness values are saturated and/or one or more regions wherein a signal to noise ratio is below a threshold value.
  • the processor further being arranged for excluding from the region of interest for each first image one or more regions wherein the brightness values are saturated and/or one or more regions wherein a signal to noise ratio is below a threshold value.
  • the determination of the decay value comprises determining a plurality of levels of brightness values at a plurality of fitting coordinates within each subregion of interest, wherein each fitting coordinate corresponds to a distance from the illumination coordinate, and fitting a mathematical function, to the levels of brightness as a function of the distance from the illumination coordinate.
  • the 'fitting coordinates' are understood to be values representative of a distance from the illumination coordinate, measured radially from the illumination coordinate.
  • the corresponding levels of brightness correspond to the brightness values present in the subregion of interest within a range around the fitting coordinate.
  • the fitting coordinates may be representative of 'bins' which correspond to certain spans of radial distance from the illumination region.
  • a 'mathematical function' is
  • Fitting may also be referred to as curve fitting or regression. Fitting is commonly known in the art.
  • the mathematical fitting function is an exponential function or comprises an exponential function.
  • exponential functions are representative for the decay of intensity of backscattered light with respect to distance from the illumination coordinate, and fitting with exponential functions may thus embody a fast an precise measure for quantifying the extent of decay, and enable assigning quantitative parameters, such as the fitting parameters, to the corresponding portion of the associated tissue sample.
  • the mathematical function may be given as a function I of distance r. where I represents a level of brightness, such as a light intensity as measured by the camera.
  • A is a constant given by the fitting process (which may or may not be used), (Greek letter alpha) is representative of the decay value, and may be referred to as the fit parameter of interest or "space constant". It is understood that I may be used interchangeably with f(r). In some embodiments, minor changes to the mathematical function may be given, such as the addition of a constant. In other embodiments, the mathematical fitting function may be given by another expression comprising the term
  • the scanning means comprises one or more optical elements for moving a light beam emitted from the light source and/or for moving the field of view of the camera.
  • An advantage of moving the light beam may be that it enables that the light source and the associated tissue sample are kept stationary, and moving, e.g ., a mirror may be faster, require less power, and the possibly fragile light source may be kept stationary.
  • moving the light beam is realized using one or more movable mirrors.
  • An advantage of moving the field of view of the camera using one or more optical elements may be that the camera, which may be relatively heavy and fragile, may then be kept fixed . In a particular
  • the camera is fixed and one or more optical elements, such as mirrors, are arranged for moving the field of view of the camera.
  • a system wherein the processor bei arranged for receiving and overlaying a third image of the associated tissue sample with the reconstruction image of the associated tissue sample.
  • the field of view of the third image is larger than the reconstruction image, such as the field of view of the third image being larger than a section of the associated tissue sample which corresponds to a section imaged by the reconstruction image, such as the field of view of the third image comprising the section of the associated tissue sample which corresponds to section imaged by the reconstruction image, such as the field of view of the third image being larger than the tissue sample under analysis.
  • An advantage of having a relatively large field of view of the third image may be that it enables overlaying the a third image with a relatively large field of view with the reconstruction image, thereby helping defining and localizing the section of the tissue sample corresponding to the reconstruction image on the associated tissue sample surface, such as on a surface of a body comprising the associated tissue sample.
  • An possible advantage of overlaying a third image of the associated tissue sample with the reconstruction image of the associated tissue sample is that the image resulting therefrom shows the reconstructed image of the tissue sample in a larger context, such as inserted in a larger "normal" image of a body area.
  • the third image may be a standard photographic image, such as a normal photography, such as a digital
  • photography such as an image obtained with a standard camera, such as a webcam.
  • a system wherein the processor being arranged for thresholding the reconstruction image of the associated tissue sample, so as to obtain a thresholded reconstruction image of the associated tissue sample, such as for enabling indication of qualitatively different regions in the associated tissue sample.
  • An advantage of thresholding may be that it enables determination of regions representative of certain values, such as particularly high or low values.
  • the light source comprises a LASER for emitting LASER light.
  • the wavelength of the emitted LASER light is within regions of the electromagnetic spectrum spanning across far infrared to ultraviolet, such as from 10 nm to 1 cm, such as within regions of the electromagnetic spectrum spanning across near infrared to the visible spectrum, such as from 380 nm to 2500 nm, such as within the visible spectrum, such as from 380-760 nm, such as the wavelength being 658 nm.
  • An advantage of having wavelength near or identical to 658 nm may be that, the contrast between healthy parts of an associated tissue sample versus bruised parts according to measurements conducted by the present inventors follows the curve of the absorption of deoxygenated blood .
  • the LASER may have a power within 0.1-100 mW, such as within 1-100 mW, such as within 1-50 mW, such as within 10-40 mW, such as 10 mW, , such as 20 mW, such as 30 mW, such as 40 mW.
  • the power of the LASER is adjusted according the type of associated tissue sample, such as according to a type of skin pigmentation, such as raising the power for darker skin.
  • the skin pigmentation is determined automatically, so as to enable automatic adjustment of the power of the LASER.
  • the system comprises a second light source emitting at a different wavelength than the light source of the system as described in the claims as appended to the description.
  • the second light source emit light having a shorter wavelength, such as for example shorter than 658 nm, such as for example 532 nm.
  • An advantage of having a second light source may be that the measurements obtained with this second light source may enable cancelling contributions from the surface of the associated tissue sample, such as contributions arising from Langer's lines and/or folds etc., which may have some impact on the quality of detection of bruises.
  • a second light source illuminating the skin with a green light, such as 532 nm, the light does not penetrate far into, e.g., skin, so information may be extracted from the image regarding a shallow layer beneath the surface.
  • red light has a greater penetrating power
  • information derived using red light comprises information both regarding surface disturbances and lower lying structures, such as the presence or absence of bruising.
  • the invention further relates to a method for providing a reconstruction image of an associated tissue sample, the method comprising
  • each illumination coordinate a first image of the associated tissue sample, where the field of view of the first image comprising a region of interest surrounding the corresponding illumination region, wherein each of the first images of the set of first images is obtained during illumination of the corresponding illumination region, wherein each of the regions of interest for an illumination coordinate being overlapping with at least one other region of interest for a different illumination coordinate, and
  • a decay value being representative of a change in a level of brightness within the subregion of interest with respect to a distance from the illumination coordinate
  • - providing the reconstruction image of the associated tissue sample comprising a plurality of pixels, wherein a position of each pixel in the plurality of pixels in the reconstruction image of the associated tissue sample corresponds to a pixel coordinate in the coordinate system, and wherein a level of brightness of each pixel is based on the decay values of the subregions of interest which comprise the pixel coordinate.
  • This aspect of the invention is particularly, but not exclusively, advantageous in that the method according to the present invention may be implemented by standard components, such as one or more cameras, scanning means, such as X- Y-tables, and computers combined for example in accordance with the first aspect of the invention, and the method may in a fast and relatively simple manner enable imaging of a subcutaneous structure of an associated tissue sample.
  • the invention further relates to a use of a system according to the first aspect for providing the reconstruction image of the associated tissue sample, such as for providing an image of a subcutaneous structure of an associated tissue sample imaging, such as for providing an image of a hematoma of an associated tissue sample, such as for providing an image of a subcutaneous blood vessels of an associated tissue sample where the
  • subcutaneous blood vessels normally being invisible to the human eye such as for providing an image of a other subcutaneous structure of an associated tissue sample where the subcutaneous structure normally being invisible to the human eye.
  • the system may also be used for examining mucous membranes, such as for the purpose of a gynaecological examination (for example after a sexual assault), screening of an inflammatory process, monitoring wound progress (such as after an operation), non-contact measurement of the pulse rate, biometrics, e.g ., for the purpose of public safety in airports.
  • a list of possible uses of the system may include: forensics (clinical forensic medicine and pathology), Clinical medicine (internal medicine), rheumatology, dermatology, traumatology (screening of tumefaction), surgery (wound healing), reconstructive surgery, evaluation of vitality of skin (burned skin and flaps), assistance to puncture of subcutaneous blood vessels, gynaecology (sexual assaults), biometry (identification of individuals), non-medical (food or powder industries).
  • the invention further relates to a computer program product being adapted to enable a computer system comprising at least one computer having a data storage means associated therewith to operate a processor arranged for
  • each pixel in the plurality of pixels in the reconstruction image of the associated tissue sample corresponds to a pixel coordinate in the a coordinate system, and wherein a level of brightness of each pixel is based on the decay values of the subregions of interest which comprise the pixel coordinate.
  • the computer program product is further adapted to enable the computer system to operate a processor arranged for controlling an operating system arranged for controlling a scanning means and a camera so as to obtain each of the first images of the set of first images during illumination of the corresponding illumination region, wherein each of the regions of interest for an illumination coordinate being overlapping with at least one other region of interest for a different illumination coordinate.
  • a processor arranged for controlling an operating system arranged for controlling a scanning means and a camera so as to obtain each of the first images of the set of first images during illumination of the corresponding illumination region, wherein each of the regions of interest for an illumination coordinate being overlapping with at least one other region of interest for a different illumination coordinate.
  • FIG 1 shows a system for providing a reconstruction image
  • FIG 2 shows in an example of a first image with a laser spot
  • FIG 3 shows a schematic illustration of a part of a first image
  • FIG 4 shows a first image comprising an illumination region
  • FIG 5 shows a data in graph
  • FIG 6 shows an example of a first image
  • FIG 7 shows the first image which has been transformed into polar coordinates
  • FIG 8 shows the image in polar coordinates
  • FIGS 9-11 represent polar plots of the parameters of the exponential function
  • FIG 12 shows an image in polar coordinates similar to FIG 8, where the light intensity values has been replaced by grayscale values corresponding to decay values derived from exponential values obtained by fitting,
  • FIG 13 shows an image corresponding to the image in FIG 12, but transformed back into the Cartesian coordinates
  • FIG 14 shows a reconstruction image
  • FIG 15-17 show reconstruction images
  • FIG 17 shows a schematic illustration of the making of the reconstruction image
  • FIG 18 shows a photographic image of the associated tissue sample
  • FIG 19 shows a reconstructed image of the associated tissue sample
  • FIG 20 shows the associated tissue sample where an incision has been made
  • FIG 21 shows a photographic image of the associated tissue sample with a bruise
  • FIG 22 shows a reconstructed image of the associated tissue sample
  • FIG 23 shows the associated tissue sample where an incision has been made
  • FIG 24 shows a photographic (third) image of the underarm of the patient, with a reconstruction image overlaid
  • FIG 25 shows a thresholded reconstruction image
  • FIG 26 shows a photographic (third) image of the leg of the patient, with a reconstruction image overlaid
  • FIG 27 shows a reconstruction image
  • FIG 28 shows subcutaneous blood vessels of an underarm of white skin
  • FIG 29 shows subcutaneous blood vessels of an underarm of dark pigmented, such as black, skin.
  • FIG 1 shows a system 100 for providing a reconstruction image of an associated tissue sample 102, the system comprising
  • a light source 104 arranged for providing localized illumination light being incident on a surface of the associated tissue sample 102, the surface of the associated tissue sample defining a coordinate system 106, so as to provide localized illumination of an illumination region 224, a position of the illumination region being centered at an illumination coordinate,
  • a camera arranged 110 for capturing a set of first images, by providing for each illumination coordinate a first image of the associated tissue sample, where the field of view 112 of the first image comprising a region of interest 114 surrounding the corresponding illumination region 224,
  • an operating system 116 arranged for controlling the scanning means 108 and the camera 110 so as to obtain each of the first images of the set of first images during illumination of the corresponding illumination region, wherein each of the regions of interest for an illumination coordinate being overlapping with at least one other region of interest for a different illumination coordinate, and - a processor 118 arranged for
  • a decay value being representative of a change in a level of brightness within the subregion of interest with respect to a distance from the illumination coordinate
  • FIG 1 furthermore shows a rack 120 mounted on the scanning means 108 so that both the light source 104 and the camera 110 may be moved similarly.
  • FIG 2 shows in the left side (a) an example of a first image 222 with a laser spot (illumination region) in the center where the pixels are saturated (note that pixels may be saturated in the very laser spot and furthermore in a region surrounding the laser spot where the intensity of the backscattered light is so high that it saturates in the final image), a surrounding halo 214 (region of interest) where the pixel values are not saturated and furthermore a black region 226 surrounding the halo region where only noise can be extracted.
  • the right hand side (b) of FIG 2 is indicated an example the areas corresponding to a (white) halo region 214, an illumination region 224 and a noise region 226 where the signal to noise value is equal to or less than unity.
  • the system comprises a light source being a diode laser module.
  • the wavelength is chosen at 658 nm which represents a tradeoff between the depth of penetration (improved with longer wavelength towards near infrared and the contrast between absorption of the blood and the fatty tissues improved with smaller wavelengths).
  • the nominal power is 40 mw for intense illumination of dark colored skin but can be reduced by insertion of a neutral density filter for investigation of light colored skin.
  • the camera is provided as a camera of the brand 'Lumenera' model 'LuOyOM' having a 75 mm focal lens. An additional webcam enables visualization of the complete scene, such as providing the third image.
  • the scanning means comprises a precision pan/tilt unit (FLIR PTU-D46) which enables the two-axis angular scan of the light source and camera.
  • FLIR PTU-D46 precision pan/tilt unit
  • the processor and operation system is combined into a personal computer (PC) with dedicated software for the control of the complete system, image acquisition and processing as well as user interface.
  • the processor is in a specific embodiment, where the light source is a laser, arranged for carrying out the steps of:
  • beam center' is used interchangeably with 'illumination coordinate') via image analysis of the second images
  • determining of the annular working area of the halo i.e., determining the exposure between noise and oversaturation, i.e., excluding from the region of interest for each first image regions wherein the brightness values are saturated - such as in the illumination region - and/or one or more regions wherein a signal to noise ratio is below a threshold value - such as regions so far from the beam centre that the signal given by the backscattered light is equal to or smaller than the noise
  • a greyscale composite image from the values of the coefficient, such as a greyscale composite image composed of angular segments having greyscale values corresponding to their respective decay values,
  • the associated tissue sample may furthermore be imaged by a standard digital color camera, such as a webcam, and the
  • parameters of the scan may be defined in a user interface showing the image of the webcam, in particular: the center and area of region to be covered, and the size and number of the x and y steps.
  • the camera and laser are mounted on the scanner (pan/tilt motorized device). For each position of the scan, the coordinates are calculated from the parameters of the scan. For each position, the laser roughly points at the center of the camera's field of view (although there may be minor variations due to parallax and topography of the associated tissue sample under investigation).
  • FIG 3 shows a schematic illustration of a part 322 of a first image comprising a halo region 314, an illumination region 324 and a noise region 326 where the signal to noise value is equal to or less than unity. Furthermore is shown a subregion of interest 328. It is noticed that the angular segment of ca. 60 degree may in other embodiments be substantially smaller, such as for example 2 degree). Furthermore, FIG 3 shows a graph indicating the brightness values I as a function of distance R from a center coordinate, such as a center of the
  • FIG 4 shows a first image comprising an illumination region and an dotted arrow indicating the position of a line along which the brightness values may be plotted as a function of distance from the illumination coordinate.
  • FIG 5 shows a data in graph, where the graph is similar to the schematic graph 330 of FIG 3. It can be seen that in the right hand side, the pixels are saturated (within the illuminiation reg ion), then follows an exponentially decaying curve (from right to left) .
  • FIG 6 shows in the left side (a) an example of a first image.
  • the illumination coordinate may be determined in the first image or in a corresponding second image.
  • the first image which has been centered so that the illumination coordinate is in the center of the image which has furthermore been cut so as to be represented in a sq uare format. Both images in FIG 6 are still represented in Cartesian coord inates.
  • FIG 7 shows the first image which has been transformed into polar coordinates, with distance r from the illumination coordinate given along the vertical axis, and the angle ⁇ (theta) given along the horizontal axis.
  • the transformation may be carried out using :
  • FIG 8 shows the image in polar coordinates where only the region of interest (between dotted lines at R_l and R_2) is shown in grey tones, the remaining portions (corresponding to the illumination region for r ⁇ R_l and regions outside the region of interest for r>R_2) have been given black values. It is noticed that neither R_l nor R_2 are constant with respect to angular value.
  • FIGS 9-11 represent polar plots of the parameters of the exponential function for each angular segment (of 2 degree width), i.e., polar plot of the decay values.
  • FIG 9 shows a polar plot of decay values of an associated tissue sample, where the associated tissue sample is human skin, and the position of the illumination coordinate corresponds to healthy skin.
  • FIG 10 shows a polar plot of decay values of an associated tissue sample, where the associated tissue sample is human skin, and the position of the illumination coordinate is next to an ecchymosis.
  • FIG 11 shows a polar plot of decay values of an associated tissue sample, where the associated tissue sample is human skin, and the position of the illumination coordinate is on top of an ecchymosis.
  • FIG 12 shows an image in polar coordinates similar to FIG 8 where only the region of interest is shown in grey tones, the remaining portions have been given white values and wherein the brightness values for each angular segment has been replaced with a grey tone value indicative of the decay value for the particular angular segment.
  • FIG 13 shows an image corresponding to the image in FIG 12, which has been transformed back into Cartesian coordinates.
  • FIG 13 thus represents a
  • FIG 14 shows a reconstruction image where multiple first images (7x13) have been analyzed as described above, and wherein each pixel of the reconstruction image corresponds to a grey tone value representative of the average of decay values for the subregions of interest (angular segments) in each first image which has a pixel corresponding to the particular pixel in the reconstruction image.
  • the step size is 0.5 cm in both the x- and y-directions, and it can be seen that rings corresponding to the individual halos (regions of interest) are still visible.
  • FIG 15 shows a reconstruction image as in FIG 14, except that more first images have been obtained and analyzed, corresponding to a step size of 0.3 cm. A smoother image structure can be observed.
  • FIG 16 shows a reconstruction image as in FIGS 14-15, except that more first images have been obtained and analyzed, corresponding to a step size of 0.1 cm. A still smoother image structure can be observed . While diminishing the step size obviously may be one way to achieve smoother images, other possible ways include increasing the laser power or increasing the time of exposure of the first images. In both cases, the radius of the halo grows.
  • FIGS 14-16 Note that in all of FIGS 14-16 the ecchymosis is visible (indicated by the dark pixels), but in FIG 15 and particular in FIG 14 with less sensitivity and resolution compared to FIG 16.
  • FIG 17 shows a schematic illustration of the generation of the reconstruction image, wherein three halos are shown, each corresponding to a halo of a first image as illustrated in FIG 3.
  • the halos are analyzed as outlined above and each pixel in the reconstruction image is given a grey tone value which corresponds to the average of the decay values of the subregions of interest which comprise the particular pixel.
  • the pixels in the region 1724 are each within the angular segment shown for each of the halos, so the pixels within the region 1724 correspond to a grey tone value representative of the average of the three decay values of the particular subregions of interest.
  • FIG 18-20 are figures relating to a first experiment (EXAMPLE 1) on a human associated tissue sample
  • FIGS 21-23 are figures relating to a second experiment (EXAMPLE 2) on another human associated tissue sample.
  • the human tissue samples stem from bodies of the Eurasian type, and are samples of buttocks and thighs. The samples have been stored in an alcohol solution (97% alcohol, 3% ketone) which is advantageous in terms of retaining the flexibility and optical properties of the skin .
  • the three layers of the skin (epidermis, dermis and hypodermis) and muscle tissue were taken to ensure maximum similarity with the surroundings where a natural ecchymosis may be found .
  • the samples have dimensions of approximately 15x10 cm with a thickness of fat varying between 1 and 3 cm .
  • the first experiment (FIGS 18-20) is conducted on a sample with a bruise which is invisible to the naked eye, the bruise corresponding to 0.5 ml of blood .
  • FIG 18 shows a photographic image of the associated tissue sample.
  • the bruise has been marked with a ring on a transparent cover sheet.
  • FIG 19 shows a reconstructed image of the associated tissue sample. The bruise is visible as a region (marked with the dotted elliptical ring) with darker pixel values.
  • FIG 20 shows the associated tissue sample where an incision has been made in order to determine the size of the bruise.
  • the length of the bruise is determined from the reconstruction image to be 0.8 cm .
  • the width is determined from the reconstruction image to be 0.5 cm. From the incision, the length is determined to be 1.8 cm, and the width is determined to be 1 cm. The incision furthermore determines that the depth is within 0.8 to 1.5 cm .
  • FIG 21 shows a photographic image of the associated tissue sample with a bruise which is invisible to the naked eye.
  • the volume of the bruise is 1 ml of blood (where the bruise has been generated by injection of a total of 1 ml of blood into the associated tissue sample) .
  • FIG 22 shows a reconstructed image of the associated tissue sample.
  • the bruise is visible as a region (marked with the dotted elliptical ring) with darker pixel values.
  • FIG 23 shows the associated tissue sample where an incision has been made in order to determine the size of the bruise.
  • the length of the bruise is determined from the reconstruction image to be 1.2 cm.
  • the width is determined from the reconstruction image to be 0.5 cm. From the incision, the length is determined to be 1.5 cm, and the width is determined to be 0.6 cm. The incision furthermore determines that the depth is within 0.2 to 0.8 cm .
  • EXAMPLES 1-2 demonstrate the ability of the current system and method to detect ecchymoses artificially created by injection of blood into the skin of human cadaver.
  • the system is able to detect ecchymoses regardless of whether they are visible to the naked eye or invisible to the naked eye.
  • the size and location of the ecchymoses detected by the system correspond well with size and location of the ecchymoses as determined by incision of the skin . It is thus confirmed, that the present system and method may be applicable for
  • FIG 24 shows a photographic (third) image of the underarm 2434 of the patient, with a reconstruction image overlaid (as indicated by the dotted rectangle 2436).
  • FIG 25 shows a thresholded reconstruction image, where the levels correspond to low 2540 (having a light grey tone), higher 2542 (having a darker grey tone) and highest 2544 (having darkest grey tone) risk of having an ecchymosis present.
  • the highest levels are indicated by the dotted circle 2538.
  • the respective levels could in an alternative embodiment have been represented using colors, such as respectively blue, green and red.
  • the associated tissue sample is given as the lateral side of the left thigh of a 14 year old person having darker skin (Tamil) who suffered from a trauma two days prior to experiment. Symptoms: Pain on palpation of the lateral side of the left thigh. Clinic: No visible lesions.
  • FIG 26 shows a photographic (third) image of the leg 2634 of the patient, with a reconstruction image overlaid (as indicated by the dotted rectangle 2636).
  • the arrow indicates the bruises within the white elliptical ring.
  • FIG 27 shows a reconstruction image.
  • the bruises are shown by a plurality of dark regions as indicated by the dotted elliptical ring 2738.
  • EXAMPLES 3-4 show that the current system and method are capable of detecting ecchymoses on the skin of living humans and in particular, that the current system and method are capable of detecting natural bruises, such as bruises being present in the skin as consequence of trauma.
  • the system and method has been shown to be capable of detecting ecchymoses on the skin of living humans with light skin and living humans with dark pigmented skin. Detection of ecchymoses on dark pigmented skin may be particularly advantageous, since the dark pigmented skin might render visual detection of bruises difficult, such as almost impossible.
  • EXAMPLES 1-4 attest that the system and method are useable for detecting ecchymoses in skin, such as in human skin, and that the system and method may be useable, e.g., as a Legal Medicine tool, such as a Legal Medicine tool in forensic clinical medicine.
  • the associated tissue sample is given as the internal side of the right underarm of a person having white skin (FIG 28) and a person having dark skin (FIG 29). In both cases, the subcutaneous blood vessels, invisible to the naked eye, are now visible.
  • the system comprises a light source (104), scanning means (108), a camera arranged (110), an operating system (116) arranged for controlling the scanning means (108) and the camera (110), and a processor (118).
  • the system is arranged for scanning an associated tissue sample with the light source, such as scanning with a laser beam, and simultaneously obtain images with the camera.
  • the images are analysed by the processor, by subdividing each image, obtain decay values representative of levels of diffused photons which are backscattering from the associated tissue sample, and hence informative in terms of the internal tissue structures.
  • the reconstruction image is composed of the decay values obtained by the scanning of the laser beam.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Biomedical Technology (AREA)
  • Molecular Biology (AREA)
  • Veterinary Medicine (AREA)
  • Biophysics (AREA)
  • Pathology (AREA)
  • Engineering & Computer Science (AREA)
  • Public Health (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Medical Informatics (AREA)
  • Physics & Mathematics (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Radiology & Medical Imaging (AREA)
  • Dermatology (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

La présente invention concerne un système pour obtenir une image de reconstruction d'un échantillon de tissu concerné (102). Le système comprend une source de lumière (104), un dispositif de balayage (108), un appareil de prise de vues agencé (110), un système d'exploitation (116) agencé pour commander le dispositif de balayage (108) et l'appareil de prise de vues (110), et un processeur (118). Le système est agencé pour balayer un échantillon de tissu concerné avec la source de lumière, par exemple avec un faisceau laser, et obtenir simultanément des images avec l'appareil de prise de vues. Les images sont analysées par le processeur, en subdivisant chaque image, pour obtenir des valeurs de décroissance représentatives de niveaux de photons diffusés qui sont rétrodiffusés à partir de l'échantillon de tissu concerné, et donnent donc des informations concernant les structures internes du tissu. L'image de reconstruction est composée des valeurs de décroissance obtenues par le balayage du faisceau laser.
PCT/EP2013/050496 2012-01-12 2013-01-11 Diaphanoscope à balayage sans contact WO2013104760A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP12150950 2012-01-12
EP12150950.9 2012-01-12

Publications (1)

Publication Number Publication Date
WO2013104760A1 true WO2013104760A1 (fr) 2013-07-18

Family

ID=47553092

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2013/050496 WO2013104760A1 (fr) 2012-01-12 2013-01-11 Diaphanoscope à balayage sans contact

Country Status (1)

Country Link
WO (1) WO2013104760A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4905702A (en) * 1986-07-22 1990-03-06 Foss Pierre N Apparatus for imaging and measuring portions of skin
US20070263226A1 (en) * 2006-05-15 2007-11-15 Eastman Kodak Company Tissue imaging system
EP1891891A1 (fr) 2006-08-21 2008-02-27 Université de Lausanne Diaphanoscope a usage medical

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4905702A (en) * 1986-07-22 1990-03-06 Foss Pierre N Apparatus for imaging and measuring portions of skin
US20070263226A1 (en) * 2006-05-15 2007-11-15 Eastman Kodak Company Tissue imaging system
EP1891891A1 (fr) 2006-08-21 2008-02-27 Université de Lausanne Diaphanoscope a usage medical

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
HORISBERGER B ET AL: "Forensic diaphanoscopy: how to investigate invisible subcutaneous hematomas on living subjects", INTERNATIONAL JOURNAL OF LEGAL MEDICINE, SPRINGER VERLAG, DE, vol. 110, no. 2, 1 January 1997 (1997-01-01), pages 73 - 78, XP002418668, ISSN: 0937-9827, DOI: 10.1007/S004140050034 *

Similar Documents

Publication Publication Date Title
US11330985B2 (en) Near-infrared optical imaging system for hemodynamic imaging, pulse monitoring, and mapping spatio-temporal features
US20170079741A1 (en) Scanning projection apparatus, projection method, surgery support system, and scanning apparatus
AU2014290137B2 (en) Disposable calibration end-cap for use in a dermoscope and other optical instruments
US20180008154A1 (en) Method for detecting hematoma, portable detection and discrimination device and related systems and apparatuses
US10156518B2 (en) Image analysis apparatus, imaging system, surgery support system, image analysis method, and storage medium
WO2013109966A1 (fr) Procédé et appareil pour imagerie quantitative hyperspectrale par fluorescence et réflectance pour guidage chirurgical
KR20150087258A (ko) 효율적인 변조 이미지 진단
US10467747B2 (en) Image analysis apparatus, imaging system, surgery support system, image analysis method, storage medium, and detection system
JP2016538095A (ja) 所定の生物学的構造体の非侵襲的検知装置
US20220095998A1 (en) Hyperspectral imaging in automated digital dermoscopy screening for melanoma
Noor et al. The properties of the cornea based on hyperspectral imaging: Optical biomedical engineering perspective
JP2017064405A (ja) 光学測定装置及び光学測定方法
JP6844093B2 (ja) 潰瘍分析用の医用画像の捕捉のための装置および方法
JP5653087B2 (ja) 光断層画像化装置及びその作動方法
EP2811890B1 (fr) Procédé et appareil de diagnostic d'une maladie des tissus
EP3351162A1 (fr) Procédé mis en uvre par ordinateur, système et produits-programmes informatiques pour caractériser une lésion de la peau
TWI435704B (zh) 口腔光學診斷裝置及其運作方法
WO2013104760A1 (fr) Diaphanoscope à balayage sans contact
JP4109132B2 (ja) 蛍光判定装置
CN114041737B (zh) 应用于内窥镜的成像装置
Racovita et al. Near infrared imaging for tissue analysis
Hu et al. A novel tool for detecting Buruli ulcer disease based on multispectral image analysis on handheld devices
Dixon et al. Toward Development of a Portable System for 3D Fluorescence Lymphography
Jung et al. Journal of Medical Diagnostic Methods

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: 13700178

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13700178

Country of ref document: EP

Kind code of ref document: A1