Variable intensity laser treatments of the skin

What is this patent about?

’371 is related to the field of non-ablative dermatological laser treatments. Specifically, it addresses the challenge of heating the dermal layers of the skin to a therapeutic level—sufficient to trigger collagen remodeling and heat-shock protein release—without exceeding the pain threshold or causing epidermal damage. The invention provides a mechanism for achieving a precise thermal plateau rather than a simple peak-and-decay profile.

The underlying idea behind ’371 is that the most effective way to stimulate skin rejuvenation without pain is to rapidly reach a target temperature window and then hold it there using a non-linear energy delivery strategy. By dynamically adjusting the optical fluence during a single, short treatment cycle, the system can overcome the natural thermal diffusion of tissue. This prevents the common problem where a constant stream of energy either takes too long to reach therapeutic levels or overshoots into temperatures that cause burning and discomfort.

The claims of ’371 focus on a handheld, self-contained laser system that utilizes specific wavelengths between 1380 nm and 1570 nm to target depths of 100 to 800 microns. The independent claims specifically protect the method of varying pulsed beam parameters—such as intensity, pulse width, or inter-pulse delay—within a brief 0.2 to 1.5 second window. This modulation is designed to maintain a dermal temperature strictly between 39 and 45 degrees Celsius while delivering a total energy density of 1.5 to 5.0 Joules per square centimeter.

In practice, the invention operates by delivering energy in distinct stages. An initial high-energy burst quickly drives the tissue to the desired temperature. The controller then shifts to a lower-energy phase to allow for thermal diffusion and prevent overshooting the pain threshold, followed by a maintenance phase that provides just enough energy to keep the temperature stable. This is achieved by shortening pulse widths, increasing the time between pulses, or stepping down the laser current as the treatment progresses.

This approach differs from prior solutions that typically use uniform pulse trains, which result in a linear temperature rise followed by a rapid drop-off. By employing a multi-group pulse strategy, the invention maximizes the time the tissue spends in the therapeutic zone. Furthermore, the integration of safety sensors ensures that the laser only fires when in full contact with the skin, preventing light leakage and ensuring the energy is delivered precisely to the targeted dermal locus.