Abstract: The method and apparatus employ a resilient element having end definition points that are constrained between stops spaced apart at a separation S. The separation S is less than a free length L between the end definition points when not constrained, causing the resilient element to bow and resulting in a displacement m of a central region of the resilient element. The displacement m changes responsive to the net change in the separation S and the free length L. When the geometry is set such that the displacement m is very small, a relatively large change in displacement m results from small net changes. The change in the displacement m can be monitored to provide a micro strain gauge. The stops can be mounted to a substrate which differs from the resilient element in its response to a selected environmental stimulus to provide a sensor for the environmental stimulus.

Abstract: The method and apparatus employ a resilient element having end definition points that are constrained between stops spaced apart at a separation S. The separation S is less than a free length L between the end definition points when not constrained, causing the resilient element to bow and resulting in a displacement m of a central region of the resilient element. The displacement m changes responsive to the net change in the separation S and the free length L. When the geomtery is set such that the displacement m is very small, a relatively large change in displacement m results from small net changes. The change in the displacement m can be monitored to provide a micro strain gauge. The stops can be mounted to a substrate which differs from the resilient element in its response to a selected environmental stimulus to provide a sensor for the environmental stimulus.

Abstract: A method and apparatus is disclosed for predicting an effective and safe laser light energy range for sub-epidermal laser surgery. The method is especially useful in controlling beam energy during the treatment of PWS. The method is accomplished by first impinging a measurement laser pulse on a predetermined treatment area, wherein the measurement laser pulse has an energy below a predetermined threshold of coagulation and below a predetermined threshold of skin damage. The thermal emission caused by the measurement laser pulse emanating from the treatment area is then detected and the delay time from the measurement laser pulse to the detection of the thermal emission is measured. The rise rate of the thermal emission is then measured. The layer thickness is then calculated based upon the delay time, wherein the layer thickness is substantially the epidermal thickness. An internal measurement temperature rise is calculated based upon the layer thickness and the rise rate.

Abstract: A non-zero feedback radiant flux reduces a radiant flux sensor's primary response excursion by keeping the total radiant flux on the sensor virtually constant. An increase in signal radiant flux is countered by a virtually equal decrease in feedback radiant flux. Reduced primary response excursion suppresses the effects of energy storage mechanisms within the sensor. Smaller response excursions decrease the sensor's response time and nonlinearity. Since many radiant flux feedback sources are virtually noiseless, radiant flux feedback does not degrade the sensor's Noise Figure.

Abstract: The thermal gain sensor detects, by a simplified method, the direction of net energy flow through a fluid-separation barrier (window). In particular, the sensor determines a balance point above which the radiant energy (solar, microwave, X-ray, etc.) gained through the barrier exceeds the energy lost through the barrier from the combined effects of convection and conduction.One application of the thermal gain sensor pertains to a solar energy collector or solar heated room. The sensor controls movable insulation panels or curtains which reduce the energy flow through the collector window (barrier) when the energy flow is in the wrong direction. The sensor may be used to either maximize or minimize the energy in the collector or room.The sensor simulates the absorptivity and convection loss of the controlled environment by means of an insulated, darkened disk slightly spaced from the barrier surface.