摘要:
In a public key cryptosystem employing the El-Gamal algorithm, secret fresh random numbers are generated at a server and private keys of users, as encrypted with a symmetric algorithm by using individual user identifying keys determined by hashing the users' respective passphrases or biometric information (fingerprint, voiceprint, retina scan, or face scan) are maintained in a store accessible to the server, and the fresh random numbers and encrypted private keys are transmitted to the user equipment when needed via a network which is not secure. In order to prevent an attacker from discovering the random numbers or employing formerly used random numbers in a block replay attack, an interchange in the nature of a challenge response protocol is employed which passes at least one secret fresh random number from the server to the user equipment while also authenticating the user to the server. In this interchange, a first random number to be distributed to the user for use in signing a document and a second random number which is to be used by the user in forming a signature of a hashing together of the first and second random numbers as part of the challenge response protocol, are supplied to the user equipment in encrypted form together with a freshness value, and a signature by the server of a hashing together of the first and second random numbers and the freshness value.
摘要:
Method and apparatus for obtaining qualitative and quantitative analysis of the optical properties or structures of tissue or turbid medium at one or more wavelengths via 1) detection at a single spatial location on the surface of a turbid medium (such as tissue) under two or more structured light conditions or 2) detection at two or more spatial locations on the surface under a single structured light condition.
摘要:
A calf/foot support and treatment table for extension, flexion, traction, distraction and lateral movement of the body of a patient includes a base adapted to rest upon a floor, and a system support assembly having an upper end and a lower end integrally secured to the base, a rigid support platform having a lower part and an upper part, said support platform pivotally secured to a pivot axle of said system support assembly; a lumbar support assembly disposed on said lower part of said support platform; and a calf/foot support assembly for linear traction.
摘要:
Method and apparatus for obtaining qualitative and quantitative analysis of the optical properties or structures of tissue or turbid medium at one or more wavelengths via 1) detection at a single spatial location on the surface of a turbid medium (such as tissue) under two or more structured light conditions or 2) detection at two or more spatial locations on the surface under a single structured light condition.
摘要:
A method of noncontact imaging for performing qualitative and quantitative analysis of wounds includes the step of performing structured illumination of surface and subsurface tissue by both diffuse optical tomography and rapid, wide-field quantitative mapping of tissue optical properties within a single measurement platform. Structured illumination of a skin flap is performed to monitor a burn wound, a diabetic ulcer, a decubitis ulcer, a peripheral vascular disease, a skin graft, and/or tissue response to photomodulation. Quantitative imaging of optical properties is performed of superficial (0-5 mm depth) tissues in vivo. The step of quantitative imaging of optical properties of superficial (0-5 mm depth) tissues in vivo comprises pixel-by-pixel demodulating and diffusion-model fitting or model-based analysis of spatial frequency data to extract the local absorption and reduced scattering optical coefficients.
摘要:
An improvement in a method for quantitative modulated imaging to perform depth sectioned reflectance or transmission imaging in a turbid medium, such as human or animal tissue is directed to the steps of encoding periodic pattern of illumination preferably with a fluorescent excitation wavelength when exposing a turbid medium to the periodic pattern to provide depth-resolved discrimination of structures within the turbid medium; and reconstructing a non-contact three dimensional image of the structure within a turbid medium. As a result, wide field imaging, separation of the average background optical properties from the heterogeneity components from a single image, separation of superficial features from deep features based on selection of spatial frequency of illumination, or qualitative and quantitative structure, function and composition information is extracted from spatially encoded data.
摘要:
An apparatus for wide-field functional imaging (WiFI) of tissue includes a spatially modulated reflectance/fluorescence imaging (SI) device capable of quantitative subsurface imaging across spatial scales, and a laser speckle imaging (LSI) device capable of quantitative subsurface imaging across spatial scales using integrated with the (SI) device. The SI device and LSI device are capable of independently providing quantitative measurement of tissue functional status.
摘要:
An apparatus for wide-field functional imaging (WIFI) of tissue includes a spatially modulated reflectance/fluorescence imaging (SI) device capable of quantitative subsurface imaging across spatial scales, and a laser speckle imaging (LSI) device capable of quantitative subsurface imaging across spatial scales using integrated with the (SI) device. The SI device and LSI device are capable of independently providing quantitative measurement of tissue functional status.
摘要:
Illumination with a pattern of light allows for subsurface imaging of a turbid medium or tissue, and for the determination of the optical properties over a large area. Both the average and the spatial variation of the optical properties can be noninvasively determined. Contact with the sample or scanning is not required but may be desired. Subsurface imaging is performed by filtering the spectrum of the illumination in the Fourier domain but other filtering approaches, such as wavelet transform, principle component filter, etc may be viable as well. The depth sensitivity is optimized by changing the spatial frequency of illumination. A quantitative analysis of the average optical properties and the spatial variation of the optical properties is obtained. The optical properties, i.e. reduced scattering and absorption coefficients are determined from the modulated transfer function, MTF.
摘要:
A method and an apparatus for noninvasively and quantitatively determining spatially resolved absorption and reduced scattering coefficients over a wide field-of-view of a food object, including fruit or produce, uses spatial-frequency-domain imaging (SFDI). A single modulated imaging platform is employed. It includes a broadband light source, a digital micromirror optically coupled to the light source to control a modulated light pattern directed onto the food object at a plurality of selected spatial frequencies, a multispectral camera for taking a spectral image of a reflected modulated light pattern from the food object, a spectrally variable filter optically coupled between the food object and the multispectral camera to select a discrete number of wavelengths for image capture, and a computer coupled to the digital micromirror, camera and variable filter to enable acquisition of the reflected modulated light pattern at the selected spatial frequencies.