Participants receive NPLT administered transcranially.

Participants receive standard care with sham NPLT (laser delivery obstructed but device setup identical).

Nano-pulsed laser therapy (NPLT) is a novel, noninvasive therapeutic modality that combines near-infrared (NIR) laser light with optoacoustic stimulation. The therapy is delivered using an Optical Parametric Oscillator (OPO) laser system capable of emitting tunable wavelengths within the near-infrared spectrum (690-950 nm).

The laser delivers nanosecond-duration pulses (10 nanoseconds) at a repetition rate of 20 Hz, with a maximum pulse energy of up to 150 millijoules per pulse. Energy delivery is precisely calibrated to 0.05 J/cm² per pulse to ensure controlled and consistent exposure. The pulsed NIR energy generates localized optoacoustic effects intended to produce acute physiological responses without tissue ablation or thermal injury.

NPLT is administered noninvasively during the acute post-injury period following moderate to severe traumatic brain injury, in accordance with the study protocol.

Feasibility will be assessed by the successful administration of NPLT acutely following moderate to severe traumatic brain injury, including protocol adherence and completion of the intervention.

Acute physiological effects will be evaluated by changes in predefined physiological parameters measured before and after NPLT administration during the acute post-injury period.