Digital moisture dermatometer
First Claim
1. An improved instrument of the type for making random, on demand measurements on the stratum corneum of the skin, said instrument having a stray field capacitance transducer for making said measurements, the improvement which comprises(a) an oscillator circuit, comprising an oscillator of predetermined frequency and said stray field capacitance transducer, whereby said oscillator frequency varies in accordance with the capacitance measurement of said transducer,(b) a readout means adapted to receive and display said oscillator frequency, and(c) a trigger means coupled to said oscillator circuit and said readout means for obtaining a reading on said readout means, said trigger means comprising means to provide a fixed frequency, means to compare said fixed frequency to said oscillator frequency, and means to enable said readout means when said oscillator frequency exceeds said fixed frequency.
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Accused Products
Abstract
An improvement in a device to measure the moisture content of the stratum corneum of human skin by means of a stray field capacitance transducer, the measurement of the stray field being accomplished by using an oscillating electronic circuit, in which said stray field capacitance being measured is a frequency determining element of the circuit, and a signal proportional to the period of oscillation of the circuit is a measurement of the relative moisture content of the outer layer of the object being measured.
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Citations
5 Claims
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1. An improved instrument of the type for making random, on demand measurements on the stratum corneum of the skin, said instrument having a stray field capacitance transducer for making said measurements, the improvement which comprises
(a) an oscillator circuit, comprising an oscillator of predetermined frequency and said stray field capacitance transducer, whereby said oscillator frequency varies in accordance with the capacitance measurement of said transducer, (b) a readout means adapted to receive and display said oscillator frequency, and (c) a trigger means coupled to said oscillator circuit and said readout means for obtaining a reading on said readout means, said trigger means comprising means to provide a fixed frequency, means to compare said fixed frequency to said oscillator frequency, and means to enable said readout means when said oscillator frequency exceeds said fixed frequency.
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4. An improved instrument of the type having a stray field capacitance transducer means for measuring, and a readout means operatively associated with said stray field capacitance transducer means, for displaying the moisture content of human skin, wherein the improvement comprises:
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(a) a measurement enabling circuit operatively associated with said readout means; (b) oscillator circuit means connected to said measurement enabling circuit and said stray field capacitance transducer means, said oscillator circuit means being responsive to said stray field capacitance transducer means being brought in contact with said human skin and thereby initiating said measurement enabling circuit, wherein said oscillator circuit means comprises a square-wave oscillator circuit, the period of the output from said oscillator circuit means being in direct proportion to the capacitance of said stray field capacitance transducer means. - View Dependent Claims (5)
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Specification