Energy-Based Devices: What to Understand Before You Buy One
Energy-based devices are sold in a language of results and operated in a language of parameters, and the gap between the two is where most complications live. A device that produced an excellent outcome in a demonstration will burn a patient if the same settings meet different skin.
This is a primer on the concepts a practitioner needs before buying, not a manual for any particular platform — those belong to the manufacturer's training, which is not optional.
What the settings actually control
Wavelength determines what absorbs the energy and how deep it reaches. Different targets — melanin, haemoglobin, water, tattoo ink — absorb different wavelengths, and across the visible and near-infrared range depth generally increases with wavelength, while infrared wavelengths strongly absorbed by water, such as erbium and CO2, act superficially. This is why a device that treats vessels well is the wrong tool for hair, and why longer wavelengths are comparatively safer in richly pigmented skin: less energy is intercepted by melanin in the epidermis on the way to the target.
Pulse duration determines how quickly energy is delivered, and therefore whether heat stays confined to the target or spreads into surrounding tissue. Delivering the same energy more slowly is one of the main levers for safety.
Fluence is how much energy is delivered. More is not better; more is simply more heat, and heat in the wrong layer is a burn.
Cooling protects the epidermis while the target heats. Inadequate or interrupted cooling converts a safe treatment into an unsafe one without any change to the other settings.
Skin type changes the whole calculation
Melanin competes for the energy intended for the target. In Fitzpatrick IV to VI this competition is significant: laser and light treatments carry a greater risk of dyspigmentation and scarring, so device and parameters must be chosen with particular care [3].
The habits that address it are simple and consistently under-used: a test patch at the intended settings with a genuine wait of days before proceeding, conservative parameters with longer pulse durations, thorough and continuous cooling, fewer passes, and longer intervals between sessions. Recent sun exposure or an active tan is a reason to postpone.
A device whose manufacturer cannot give clear guidance for darker skin types is a device with a restricted patient population, and that should be understood before purchase rather than after.
What regulatory status means
Devices sold in the European Union are regulated as medical devices, with obligations covering clinical evidence, labelling, traceability and post-market surveillance. That framework is meaningful, and asking to see a device's regulatory documentation is a reasonable question rather than an awkward one [1].
What it does not mean is that a device is suitable for every indication a distributor mentions, or for every patient. Regulatory clearance describes what the manufacturer demonstrated, not what a salesperson claims. It also does not transfer competence: the practitioner remains responsible for the settings chosen and the patient selected.
Questions worth asking before buying
- What is the regulatory status, and for which indications specifically?
- What training is included, who delivers it, and is it hands-on?
- What is the manufacturer's guidance for darker skin types?
- What service and calibration arrangements exist, and what happens when the device is out of action?
- What consumable costs are involved per treatment, and how many treatments does the business case assume?
- Who do you call at nine in the evening when a patient has an unexpected reaction?
Before the first patient
Eye protection for everyone in the room, appropriate to the wavelength, is not a formality. Staff exposed to laser and intense light need a risk assessment, warning signs, restricted access to the treatment area, protective equipment and training [2]. Documented settings for every treatment and a written plan for adverse events also belong in place before the first appointment rather than after the first incident.
Read next
- Treating Skin of Colour: Injectables and Devices Across Fitzpatrick Types
- Laser Plume in the Aesthetic Clinic: Protecting the Operator
- CO2 laser training: what a first course should cover