Abstract:
A multichannel optical head and data storage system employs an integrated-optical read channel. The read channel may be fabricated on a planar waveguide structure that separates the data signals of the multiple lasers. The read channel includes focus error sensors and track error sensors. The optical head may be used for amplitude recording systems such as phase-change erasable and write-once media, ablation media, dye-polymer media, and OD-ROM systems.
Abstract:
A mask is used to remove substantially all of the first order diffraction components of a reflected light beam which are generated as the beam crosses grooved data tracks in an optical media. The mask may comprise a transparent substrate with an opaque layer having a pair of circular apertures or a bow-tie shaped aperture. The apertures are located outside the regions of interference between the diffracted components and the undiffracted component. The layer may be made of a reflective material for reflecting diffracted components of the reflected beam to a tracking error sensor. The layer may be made of a holographic material for deflecting the diffracted components to a tracking error sensor.
Abstract:
A cassette for retaining a specimen of surgically exposed tissue from a patient in an orientation that facilitates optical sectioning of the tissue by a confocal microscopic or other optical imaging microscope. The cassette includes a base member having an optically transparent window upon which a tissue specimen is situated, a membrane locatable over a substantial portion of the base member including the window, and an upper member which can cover the base member to provide an enclosed cavity between the membrane and the window sealing the tissue specimen therein. The edges of the tissue specimen may then be positioned planar against the window and retained in that position by bonds formed between the membrane and window around the tissue specimen. The cassette may be part of a confocal imaging system to produce microscopic images of sections of the tissue specimen useful for Mohs surgery.
Abstract:
A handheld confocal imaging system for in vivo observation of dermal and subdermal tissue allows diagnosis of conditions substantially beneath the surface of the skin. A confocal head has optics which scan the tissue so as to provide images of vertical sections of the tissue. Both two and three dimensional imaging may be provided for diagnosis and location of basal cell carcinomas and melanomas, and so as to enable visualization of tumor borders prior to excision.
Abstract:
A confocal scanning microscope system (10) using cross polarization effects and an enhancement agent (acetic acid) to enhance confocal microscope reflectance images of the nuclei of BCCs (basal cell carcinomas) and SCCs (squamous cell carcinomas) in the confocal reflectance images of excised tumor slices. The confocal scanning microscope system having a laser (11) for generating an illumination beam (12), a polygon mirror (18) for scanning the beam to a tissue sample (22) and for receiving a returned beam from the tissue sample and detector (28) for detecting the returned beam to form an image. The system further includes a half-wave plate (13) having a rotatable stage (14) and a quarter-wave plate (21) having a rotatable stage (20) disposed in the optical path of the illumination beam and at least a linear polarizer (24) having a rotatable stage (25) disposed in the optical path of the returned beam from the tissue sample.
Abstract:
A display (34) provides from digital images of an excised tissue specimen the orientation and location of tissue and regions of interest (cancers). Images of slices through excised specimen are obtained using a confocal microscope (10) to obtain confocal maps to provide a mosaic of images each of which corresponds to a different map element. A macroscopic image of significant map elements and high resolution images of selected elements are provided to locate and mark regions which are cancerous thereby assisting the surgeon to excise such regions.
Abstract:
A system using cross polarization effects and an enhancement agent having citric or other similar alpha hydroxy acid to enhance confocal microscope reflectance images and particularly images of the nuclei of BCCs (basal cell carcinomas) and SCCs (squamous cell carcinomas) in the confocal reflectance images of excised tumor slices obtained during Mohs surgery by illuminating the tissue being imaged (a tumor slice) using polarized light. The reflected illumination is passed to a polarization analyzer, which passes the polarization component which is crossed with respect to the polarization of the illuminating light. The light from the analyzer is passed through the confocal aperture and detected. The section of the tissue either at the surface or within the tissue is scanned and the reflectance image is produced with enhanced visualization of the cellular or nuclear structure thereof thereby enabling determination of the extent of the tumor (cancerous cells) in the section. A method is also provided using the system for diagnosing cancerous cells in skin tissue.
Abstract:
A system is provided for marking on a recording medium (36), such as a label, the location of imaged tissue with respect to an exposed surface of the tissue (34). Tissue is imaged by a microscope (11) capable of imaging sections of the tissue below the exposed tissue surface through optics. A ring (32) applied to the surface of the tissue stabilizes the tissue to the optics and localizes a portion of the tissue surface through an aperture in the ring. An actuator (38) is connected to both the ring and the microscope for moving the ring to adjust the position of the tissue with respect to the optics, thereby allowing an operator of the system to survey different images of tissue sections with the microscope.
Abstract:
The quality of images produced by confocal microscopy, and especially scanning laser confocal microscopy, is enhanced especially for images obtained in turbid mediums such as many biological tissue specimens, by reducing speckle from scatterers that exist outside (above and below) the section which is being imaged by utilizing sheared beams, both of which are focused to laterally or vertically offset spots and polarizing the beams to have opposite senses of circular polarization (right and left handed circular polarization). The return light from the section of certain polarization is detected after passing through the confocal aperture of the confocal microscope. Images can be formed using optical coherence detection of the return light. Light from scatterers outside the section of interest, which are illuminated by both of the sheared beams, interfere thereby reducing speckle due to such scatterers, and particularly scatters which are adjacent to the section being imaged. Sheared beams having orthogonal linear polarization, as may be obtained from a Wollaston or Nomarski prism are converted into circularly polarized beams of opposite polarization sense by a quarter wave plate and focused into laterally displaced spots. A Dyson type lens is used to obtain sheared beams which when focused form vertically displaced spots. The optical signals representing reflections from the section are derived by polarizing optics which may either be a polarizing beamsplitter in the incident beam path or a retarder and analyzer. The retarder may be selected to provide different polarization phase shifts of the return light, and with the analyzer, detects the degree of elliptical polarization representing the optical activity and circular dichroism producing the optical signal representing the image.
Abstract:
An improved system for confocal imaging within dermal tissue of a patient is provided which minimizes instability in confocal images by reducing the relative motion of the tissue with respect to the confocal imaging optics of the system. The system includes a mechanism for maintaining an area of skin tissue under stress by application of force at the edges of the area, and an imaging head coupled to this mechanism for imaging the stressed skin. The mechanism includes a mechanical structure, such as a platen, brace, or attachment, which both supports the imaging head of the system and applies stress to a limited surface area of the tissue to minimize skin motion during confocal imaging.