Claims
- 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.
- 2. The apparatus of claim 1, wherein said source of light is a laser.
- 3. The apparatus of claim 1, wherein said source of light is a pulsed laser.
- 4. The apparatus of claim 1, wherein said source of light is a pulsed source of light.
- 5. The apparatus of claim 4, wherein said first incremental signal is produced by a first pulse generated by said pulsed source of light.
- 6. The apparatus of claim 5, wherein said threshold comparator compares the incremental signal after a given pulse is generated by said pulsed source of light with the incremental signal measured after said first pulse is generated by said pulsed source of light.
- 7. The apparatus of claim 6, wherein said threshold comparator is set to be triggered when a scatter intensity of a given pulse of light differs from a scatter intensity of said first pulse of light by at least about 5%.
- 8. The apparatus of claim 6, wherein said threshold comparator is set to be triggered when a scatter intensity of a given pulse of light differs from a scatter intensity of said first pulse of light by at least about 10%.
- 9. The apparatus of claim 1, wherein at least one of said means for commanding the signal generator to generate a signal, said means for commanding the sample and hold circuit to hold the first incremental signal received from said amplifier, said means for commanding the 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, or said means for resetting said threshold comparator is a microcontroller.
- 10. The apparatus of claim 1 wherein said broadband detector has a bandwidth ranging from about 800 nm to about 1700 nm.
- 11. The apparatus of claim 1, wherein said signal generator is a pulse generator.
REFERENCE TO RELATED APPLICATION
This application is a divisional of U.S. application Ser. No. 08/823,940, filed on Mar. 25, 1997, now U.S. Pat. No. 6,027,496;
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Non-Patent Literature Citations (1)
Entry |
Goldsmith, Physiology, Biochemistry, and Molecular Biology of Skin, Oxford University Press (1991), Chapters 1-2. |