Pulse width modulation control for battery-powered laser device

A control system for a dermatological treatment device including a laser unit comprising at least one laser diode configured to emit laser radiation at a wavelength between 1400 nm and 2000 nm, suitable for non-ablative fractional photothermolysis, a battery unit, and at least one sensor configured to generate sensor signals, the control system comprising:

• a laser drive circuit comprising the laser unit, the battery unit, a first switch, and a second switch;
• wherein the laser unit is arranged in series between the first switch and the second switch;
• control electronics configured to control the laser unit, during manual movement of the dermatological treatment device across the surface of the user's skin, to generate a sequential series of discrete, non-continuous wave (non-CW) treatment pulses at the wavelength between 1400 nm and 2000 nm and delivered to a user's skin to form a sequential series of non-ablative treatment spots spaced apart from each other on the skin by:
• controlling the first switch based at least on sensor signals from the at least one sensor;
• controlling the second switch using multi-level pulsing control signals including:
• (a) treatment pulse control signals defining at least one pulse characteristic for each of the sequential series of discrete, non-CW treatment pulses at the wavelength between 1400 nm and 2000 nm suitable for non-ablative fractional photothermolysis, each treatment pulse having a treatment pulse duration in a range between 0.5 ms and 10 ms and producing a corresponding non-ablative treatment spot on the skin, and
• (b) pulse width modulation (PWM) control signals that define a PWM waveform within each of the discrete, non-CW treatment pulses, thereby delivering current from the battery unit to the laser unit with a PWM current waveform during each treatment pulse,
• wherein the PWM current waveform for each treatment pulse includes a series of multiple PWM pulses that forms a single treatment spot in the skin that is spaced apart from other treatment spots formed by other treatment pulses by non-treated areas of skin, to thereby provide a fractional photothermolysis treatment in the skin.

A control system for a dermatological treatment device including a laser unit comprising at least one laser diode, a battery unit, and at least one sensor configured to generate sensor signals, the control system comprising:

• a laser drive circuit comprising the laser unit, the battery unit, a first switch, and a second switch;
• wherein the laser unit is arranged in series between the first switch and the second switch;
• and
• control electronics configured to:
• control the first switch based at least on sensor signals from the at least one sensor;
• and
• control the second switch using pulse width modulation (PWM) during each of a series of discrete, non-continuous wave (non-CW) treatment pulses, each treatment pulse having a treatment pulse duration in a range between 1 ms and 700 ms, thereby delivering current from the battery unit to the laser unit with a PWM current waveform during each treatment pulse, wherein the PWM current waveform for each treatment pulse includes a series of multiple PWM pulses within the respective treatment pulse;
• receive sensor signals generated by the at least one sensor based on an interaction with a user's skin;
• and dynamically adjust at least one waveform profile parameter of the PWM current waveform for a particular treatment pulse in real time during the particular treatment pulse based on the received sensor signals.