Abstract: A spectrophotometer which is highly manufacturable at minimum cost nevertheless provides precision of measurement of spectra components of light which is projected therein by maintaining precise optical alignment of optical and electrical components thereof. These components are mounted in a module which is contained in a housing having an entrance aperture which defines an object area for light the spectrum of which is measured by a photodetector in the module at an image area. The module has a base plate provided by a printed circuit board on which a closed wall encompasses an area (a corral) on one side of the circuit board. The wall is a one piece structure which extends to the vicinity of the edge of the board. It is assembled with the board as a unitary structure so that the assembly is made torsionally rigid and resists bending in the plane of the board. The module may be of sufficiently small size so as to be located in a housing which is hand held, thereby providing a hand-held spectrophotometer.

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: An improved photodetector integrator circuit is provided having a photodetector, such as a photodiode, which produces photocurrent responsive to incident illumination. The photodetector is coupled to an integrator stage which converts the photocurrent into voltage and integrates the voltage over an integration period to provide an output signal. A window comparator in the circuit receives the output signal from the integrator stage and compares the output signal to a first threshold and a second threshold to provide, as a measurement signal, a pulse having a width which corresponds to the time interval over which the output signal increases from the first threshold to the second threshold. In the window comparator, the second threshold is greater than the first threshold.

Abstract: A spectrophotometer which is highly manufacturable at minimum cost nevertheless provides precision of measurement of spectra components of light which is projected therein by maintaining precise optical alignment of optical and electrical components thereof. These components are mounted in a module which is contained in a housing having an entrance aperture which defines an object area for light the spectrum of which is measured by a photodetector in the module at an image area. The module has a base plate provided by a printed circuit board on which a closed wall encompasses an area (a corral) on one side of the circuit board. The wall is a one piece structure which extends to the vicinity of the edge of the board. It is assembled with the board as a unitary structure so that the assembly is made torsionally rigid and resists bending in the plane of the board. The module may be of sufficiently small size so as to be located in a housing which is hand held, thereby providing a hand-held spectrophotometer.

Abstract: In order to preclude unreliable or inaccurate spectrophotometric measurements which can be caused by thermal effects (expansion/contraction) of components of the spectrophotometer, such as the dispersive element, the arm or mounting for changing the orientation of the element to scan the spectrum and produce spectral measurements, the element, and also displacement of the photodetector, lenses and other optical elements which can caused thermal effects, and also to reduce temperature-related errors in the photodetector or other electronics of the spectrophotometer, a temperature sensor is disposed in thermally coupled relationship within the spectrophotometer housing. A motor, which is coupled to the arm to change the orientation of the element and to the motor controller, is programmed to utilize the motor as a heat source in response to the temperature of the spectrophotometer detected by the sensor when the motor is not actuating the element grating to provide spectral measurements.

Abstract: A robust spectrophotometer (also known as a color spectrometer or colorimeter) is self contained in a housing which is adapted to be held-held and has all of the electrical, optical and electro optic elements mounted on a board captured within the housing at one end of which light from a sample is restricted to an object area and projected after being dispersed spectrally, as with a reflection grating, to an image area at a photodetector via a lens which has an optical axis and converges the dispersed light at the image area. The dispersive element is mounted on an arm having a pivot laterally offset from the dispersive element's surface where a diverging beam of light from the object area is incident and is deflected to the image area. The geometry is such that the dispersive element may be rotated to a position where the beam is specularly deflected (zeroth order diffraction), and the spectrometer calibrated when the dispersive element is in the specular reflection/deflection position.

Abstract: A hand held microsurgical instrument for applying laser energy to selected locations (sites) in an area under the skin (or other exposed translucent tissue) to provide localized photothermolysis of underlying tissue at these sites, is described. The laser energy is focused into a spot within the tissue. This spot is of sufficiently small size so that the energy density is sufficient to provide surgical or treatment effects within the tissue without damaging the surface tissue. In dermatology, for example, the technique can be used to destroy endothelial cells in blood vessels which are desired to be removed, such spider veins (nevi) in the skin, hair follicles to prevent hair growth therefrom, or other microsurgical procedures. The area is visualized while the laser beam is steered, using a deflection system, in X and Y coordinates.

Abstract: An electro-optical sensor senses marks on a sheet which travels longitudinally with respect to a printed circuit board, carrying linear arrays of light sources (LEDs) and photodetectors and optics which define zones displaced laterally across the width of a sheet of paper, longitudinal columns of which can contain marks, the presence and absence of which marks is detected by the sensor. The sensor is especially adapted for use in detecting marks which indicate votes on paper ballots in electronic, computerized vote counting apparatus.

Abstract: In order to permanently remove hair growing in subcutaneous (below the skin's surface) tissue and to do so permanently, the hair and its root structure is epilated (vaporized) in an ablation cavity of essentially the same size and shape as the volume occupied by the root structure which includes follicle, the follicle bulb and the dermal papilla. Optical energy is used which is of a wavelength and fluence sufficient to cause epilation in the cavity without relying upon selective photothermolysis thereby limiting damage to tissue outside of the hair root structure. To find and restrict the optical energy to the epilation cavity, an optical system, which may be constituted of a single lens, having a numerical aperture of F/5-5.8 is used. The beam is generated by a laser which may be operated in a pulse mode and contained in a hand piece having the optical system at the end thereof.

Abstract: In order to digitize with sufficient resolution an analog signal, which may be generated by a photodetector in a spectrophotometer, an improved analog to digital conversion system is provided having an integrator stage, an analog to digital converter, a microprocessor and interface circuits for providing communication between the microprocessor and a host computer. The integrator may include an operational amplifier with a capacitor in feedback relationship therewith for providing an output which varies linearly as function of time. The microprocessor operates the analog to digital converter to sample the integrator output at successive increments of time which increase in accordance with a binary relationship to an increment corresponding in binary value to the desired upper end of the resolution range. The digitized samples from the analog to digital converter are compared with a predetermined value in the upper end of the amplitude range of the converter.