Removal of stratum corneum by means of light
First Claim
1. Apparatus for forming an opening in a region of the stratum corneum of a patient comprising:
- (a) a source of light for providing energy to form an opening in the stratum corneum;
(b) a lens assembly for collimating and focusing light from the source of light onto the surface of the stratum corneum;
(c) a broadband detector for detecting a signal related to the intensity of light reflected from the surface of the stratum corneum and from interstitial fluid that fills the opening formed in the stratum corneum by the collimated, focused light from the source of light;
(d) an amplifier for increasing the signal detected by the broadband detector;
(e) a sample and hold circuit for holding the first incremental signal received from said amplifier;
(f) a threshold comparator for comparing an incremental signal received from said amplifier subsequent to the first incremental signal received from said amplifier;
(g) a signal generator and power control circuit for generating a signal to cause a driver circuit to drive current needed to operate said source of light at a desired power level;
(h) a means for commanding said signal generator to generate a signal;
(i) a means for commanding said sample and hold circuit to hold the first incremental signal received from said amplifier;
(j) a means for commanding said threshold comparator to compare (1) an incremental signal received from said amplifier subsequent to the first incremental signal with (2) the first incremental signal received from said amplifier; and
(k) a means for resetting said threshold comparator.
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Accused Products
Abstract
A method for increasing the permeability of the stratum corneum by means of a source of light, preferably a laser, more preferably a pulsed laser. By increasing the permeability of the stratum corneum, access to the interstitial fluid is achieved, thereby enabling measurement of analytes in the interstitial fluid. In one aspect, the method comprises the steps of:
(a) providing a source of light having a wavelength of from about 930 nm to about 1040 nm; and
(b) exposing a region of the stratum corneum of the patient to said source of light for a period of time sufficient to form an opening in the stratum corneum.
Preferably, exposure of the region of the stratum corneum to the source of light is ceased when an amount of interstitial fluid fills the opening in the stratum corneum, which amount is sufficient to cause the scatter intensity of the light reflected from the surface of the interstitial fluid occupying the opening in the stratum corneum to differ from the scatter intensity of the light reflected from a region of the stratum corneum that is substantially free of interstitial fluid. The invention also involves an apparatus for carrying out the foregoing method.
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Citations
11 Claims
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1. Apparatus for forming an opening in a region of the stratum corneum of a patient comprising:
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(a) a source of light for providing energy to form an opening in the stratum corneum;
(b) a lens assembly for collimating and focusing light from the source of light onto the surface of the stratum corneum;
(c) a broadband detector for detecting a signal related to the intensity of light reflected from the surface of the stratum corneum and from interstitial fluid that fills the opening formed in the stratum corneum by the collimated, focused light from the source of light;
(d) an amplifier for increasing the signal detected by the broadband detector;
(e) a sample and hold circuit for holding the first incremental signal received from said amplifier;
(f) a threshold comparator for comparing an incremental signal received from said amplifier subsequent to the first incremental signal received from said amplifier;
(g) a signal generator and power control circuit for generating a signal to cause a driver circuit to drive current needed to operate said source of light at a desired power level;
(h) a means for commanding said signal generator to generate a signal;
(i) a means for commanding said sample and hold circuit to hold the first incremental signal received from said amplifier;
(j) a means for commanding said threshold comparator to compare (1) an incremental signal received from said amplifier subsequent to the first incremental signal with (2) the first incremental signal received from said amplifier; and
(k) a means for resetting said threshold comparator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification