Abstract: The Doppler bandwidth extracted from the standard deviation of the frequency shift in phase-resolved optical Doppler tomography (ODT) is used to image the velocity component transverse to the probing beam. The effective numerical aperture (NA) of the optical objective determines the slope of the dependence of the standard deviation on velocity. In the case where the angle between the probing beam and flow direction is within ±15 degrees to the perpendicular, the Doppler frequency shift is very sensitive to angle position while the Doppler bandwidth is insensitive to flow direction. Linear dependence of the flow velocity on the Doppler bandwidth allows accurate measurement of flow velocity without precise determination of flow direction. In addition, it also extends the dynamic range of the average frequency shift mapping method used in the phase-resolved ODT.

Abstract: A photoacoustic probe for port wine stain (PWS), burn and melanin depth measurements is comprised of optical fibers for laser light delivery and a piezoelectric element for acoustic detection. The probe induced and measured photoacoustic waves in acryl amide tissue phantoms and PWS skin in vivo. Acoustic waves were denoised using spline wavelet transforms, then deconvolved with the impulse response of the probe to yield initial subsurface pressure distributions in phantoms and skin. The waves were then analyzed for epidermal melanin concentration, using a photoacoustic melanin index (PAMI) related to the amount of laser energy absorbed by melanin. Propagation time of the photoacoustic wave was used to determine the depth of blood perfusion underlying necrotic, burned tissue. Thus, the photoacoustic probe can be used for determining PWS, burn and melanin depth for most patients receiving laser therapy.

Abstract: The invention is a technique for dynamic measurements of the heat transfer coefficient to the outer layer of the skin surface using a high thermal conductivity metal in an insulating block as the standardized target. The coefficient is dependent on the specific design of the cryogen valve and nozzle, and values up to 11 500 W/m2K values were measured for a 100 ms long spurts. The values for longer spurts are dependent on air humidity, as ice/snow formation then tends to form a thermally insulating layer. The average value of the heat transfer coefficient for a 200 ms long spurt was determined to 8000 W/m2K for conditions of normal room humidity and temperature. The technique enables an improved prediction of the temperature profile and cooling efficiency during therapy, and may thereby contribute to an improved therapeutic outcome.

Abstract: A phase-resolved functional optical coherence tomography system simultaneously obtains the Stokes vectors, structure, blood flow velocity, standard deviation, and birefringence images in human skin. The multifunctional images were obtained by processing the analytical interference fringe signals derived from the two perpendicular polarization detection channels. The blood flow velocity and standard deviation images were obtained by comparing the phase from the pairs of analytical signals in the neighboring A-lines in the same polarization state. The Stokes vectors were obtained by processing the analytical signals from two polarization diversity detection channels for the same reference polarization state. From the four Stokes vectors, the birefringence image, which is insensitive to the orientations of the optical axis in the sample, was obtained. Multifunctional images of a port wine stain birthmark in human skin are demonstrated.

Abstract: In optical coherence tomography (OCT), Axial and lateral resolutions are determined by the source coherence length and numerical aperture of the sampling lens, respectively. While axial resolution can be improved using a broadband light source, there is a trade-off between lateral resolution and focusing depth when conventional optical elements are used. The incorporation of an axicon lens into the sample arm of the interferometer overcomes this limitation. Using an axicon lens with a top angle of 160 degrees, 10 &mgr;m or better-lateral resolution is maintained over a focusing depth of at least 6 mm. In addition to high lateral resolution, the focusing spot intensity is approximately constant over a greater depth range.

Abstract: The Doppler bandwidth extracted from the standard deviation of the frequency shift in phase-resolved optical Doppler tomography (ODT) is used to image the velocity component transverse to the probing beam. The effective numerical aperture (NA) of the optical objective determines the slope of the dependence of the standard deviation on velocity. In the case where the angle between the probing beam and flow direction is within ±15 degrees to the perpendicular, the Doppler frequency shift is very sensitive to angle position while the Doppler bandwidth is insensitive to flow direction. Linear dependence of the flow velocity on the Doppler bandwidth allows accurate measurement of flow velocity without precise determination of flow direction. In addition, it also extends the dynamic range of the average frequency shift mapping method used in the phase-resolved ODT.

Abstract: The invention is a fast-scanning ODT system that uses phase information derived from a Hilbert transformation to increase the sensitivity of flow velocity measurements while maintaining high spatial resolution. The significant increases in scanning speed and velocity sensitivity realized by the invention make it possible to image in vivo blood flow in human skin. The method of the invention overcomes the inherent limitations of the prior art ODT by using a phase change between sequential line scans for velocity image reconstruction. The ODT signal phase or phase shifts at each pixel can be determined from the complex function, {tilde over (&Ggr;)}ODT(t), which is determined through analytic continuation of the measured interference fringes function, &Ggr;ODT(t), by use of a Hilbert transformation, by electronic phase demodulation, by optical means, or a fast Fourier transformation. The phase change in each pixel between axial-line scans is then used to calculate the Doppler frequency shift.

Abstract: The invention is a technique for dynamic measurements of the heat transfer coefficient to the outer layer of the skin surface using a high thermal conductivity metal in an insulating block as the standardized target. The coefficient is dependent on the specific design of the cryogen valve and nozzle, and values up to 11 500 W/m2K values were measured for a 100 ms long spurts. The values for longer spurts are dependent on air humidity, as ice/snow formation then tends to form a thermally insulating layer. The average value of the heat transfer coefficient for a 200 ms long spurt was determined to 8000 W/m2K for conditions of normal room humidity and temperature. The technique enables an improved prediction of the temperature profile and cooling efficiency during therapy, and may thereby contribute to an improved therapeutic outcome.

Abstract: A remote test module is disclosed for selectively interfacing a plurality of test channels between a tester interface and a plurality of specialized pins connected to a device-under-test. The tester interface is coupled to a test controller for generating predetermined test signals. The remote test module includes a signal conditioner responsive to the test controller for modifying said predetermined test signals into module test signals and applying the module test signals to the specialized pins of the device-under-test and a connection apparatus. The connection apparatus has a plurality of conductive paths for coupling the signal conditioner between the tester interface and the specialized pins.

Abstract: A method for performing laser treatment of biological tissues is performed by cooling a selected portion of the biological tissue for a predetermined first time period to establish a predetermined nonequilibrium dynamic temperature gradient through the tissue so that substantially only the selected portion of the biological tissue is cooled by a predetermined minimum temperature drop. The temperature gradient is established by providing a spurt of a predetermined amount of cryogenic liquid in direct contact with the biological tissue. A superficial and deeper part of the selected portion of the biological tissue is immediately irradiated for a time period which is approximately equal to or in excess of one millisecond. The irradiation is effective to thermally treat the deeper part of the biological tissue while leaving the superficial part of the biological tissue substantially undamaged.

Abstract: Employing a low coherence Michelson interferometer, two dimensional images of optical birefringence in turbid samples as a function of depth are measured. Polarization sensitive detection of the signal formed by interference of backscattered light from the sample and a mirror or reference plane in the reference arm which defines a reference optical path length, give the optical phase delay between light propagating along the fast and slow axes of the birefringence sample. Images showing the change in birefringence in response to irradiation of the sample are produced as an example of the detection apparatus and methodology. The technique allow rapid, noncontact investigation of tissue or sample diagnostic imaging for various medical or materials procedures.

Abstract: Dynamically cooling the epidermis of a port wine stain patient undergoing laser therapy permits maximization of the thermal damage to the port wine stain while at the same time minimizing nonspecific injury to the normal overlying epidermis. A cryogenic spurt is applied to the skin surface for a predetermined short period of time in the order of tens of milliseconds so that the cooling remains localized in epidermis while leaving the temperature of deeper port wine stain vessels substantially unchanged. The result is that epidermal denaturation and necrosis which normally occurs in uncooled laser irradiated skin sites does not occur and that clinically significant blanching of the port wine stains at the dynamically cooled sites establishes that selective laser photothermolysis of the port wine stain blood vessels is achieved. In addition, dynamic epidermal cooling reduces patient discomfort normally associated with flashlamp-pumped pulsed dye laser therapy.

Abstract: Cryogen spray cooling of skin surface with millisecond cryogen spurts is an effective method for establishing a controlled temperature distribution in tissue and protecting the epidermis from nonspecific thermal injury during laser mediated dermatological procedures. Control of humidity level, spraying distance and cryogen boiling point is material to the resulting surface temperature. Decreasing the ambient humidity level results in less ice formation on the skin surface without altering the surface temperature during the cryogen spurt. For a particular delivery nozzle, increasing the spraying distance to 85 millimeters lowers the surface temperature. The methodology comprises establishing a controlled humidity level in the theater of operation of the irradiation site of the biological tissues before and/or during the cryogenic spray cooling of the biological tissue. At cold temperatures calibration was achieved by mounting a thermistor on a thermoelectric cooler.

Abstract: Optical Doppler tomography permits imaging of fluid flow velocity in highly scattering media. The tomography system combines Doppler velocimetry with high spatial resolution of partially coherent optical interferometry to measure fluid flow velocity at discrete spatial locations. Noninvasive in vivo imaging of blood flow dynamics and tissue structures with high spatial resolutions of the order of 2 to 10 microns is achieved in biological systems. The backscattered interference signals derived from the interferometer may be analyzed either through power spectrum determination to obtain the position and velocity of each particle in the fluid flow sample at each pixel, or the interference spectral density may be analyzed at each frequency in the spectrum to obtain the positions and velocities of the particles in a cross-section to which the interference spectral density corresponds.

Abstract: Successful laser treatment of hemangiomas requires selective photocoagulation of subsurface targeted blood vessels without thermal damage to the overlying epidermis. An apparatus for in vivo exposure of laser radiation from a continuous Nd:YAG laser at 1064 nm delivers repetitive cryogen spurts, each having a duration of the order of milliseconds during continuous laser irradiation. Control of the cryogen spray cooling is achieved through monitoring of the radiometric surface temperature of the tissue site and either controlling the repetition rate of the cryogen spurts according to temperature or according to a threshold temperature of the irradiated surface and/or repetition rate of the cryogen spurts according to power density and the duration of continuous irradiation.

Abstract: The invention is the improved process and method of DNA banking in which DNA or other genetic material is collected and stored, preserved, banked in a home/self-storage setting. Home/self-storage is to mean "not commercially banked." The invention includes the manufacture of kits designed to collect and bank DNA and other genetic material in a home/self-storage setting. The objective of the invention is to preserve genetic material in the event that it is needed for genetic analysis, genetic testing, genetic diagnosis, genetic therapy, forensic analysis, identification.

Abstract: Dynamically cooling the epidermis of a port wine stain patient undergoing laser therapy permits maximization of the thermal damage to the port wine stain while at the same time minimizing nonspecific injury to the normal overlying epidermis. A cryogenic spurt is applied to the skin surface for a predetermined short period of time in the order of tens of milliseconds so that the cooling remains localized in epidermis while leaving the temperature of deeper port wine stain vessels substantially unchanged. The result is that epidermal denaturation and necrosis which normally occurs in uncooled laser irradiated skin sites does not occur and that clinically significant blanching of the port wine stains at the dynamically cooled sites establishes that selective laser photothermolysis of the port wine stain blood vessels is achieved. In addition, dynamic epidermal cooling reduces patient discomfort normally associated with flashlamp-pumped pulsed dye laser therapy.

Abstract: There is disclosed a method for the convenient storage of material, especially noxious or radioactive material, which method comprises entrapping the material within a solid by bombarding the solid with ions of the material so as to form a concentration of the material within the solid.Forms of apparatus for carrying out this method are also described.

Abstract: In catalytic gas phase reactions there is used a catalyst comprising a sputtered deposit of catalytic material equivalent to between 0.5 and 5 monatomic layers upon a hard, substantially non-porous substrate. The substrate being hard and non-porous is of low surface area, that is not greater than 20 square meters per gram, and preferably comprises particles having a size in the range 0.1 micron to 0.5 centimeters.

Abstract: An apparatus for purifying exhaust waste gases including a catalytic element comprising a substrate of metal carrying a surface layer compatible with and supporting a coating of catalytic material, a major proportion of the surface coating of catalytic material comprising an unagglomerated atomic dispersion. An example of such a substrate is an aluminum bearing ferritic steel which has been heat treated in air to form an essentially alumina surface layer.