PHOTOBIOMODULATION DOSING A drug-free, surgery-free, non-invasive pain treatment alternative PBM dosing - the k ey to results Dosimetry in photobiomodulation (PBM) therapy is highly complicated - no single “dose” will work for all possible PBM therapies, and in some cases, different dosimetries can be equally effective. Safe and effective PBM dosimetry must consider multiple treatment parameters including: wavelength, irradiance (often called power density or brightness), and irradiation time . 28 In-vivo studies have shown us that tissue with higher numbers of mitochondria, like muscle, which also tend to be deeper, respond best to higher dosages. While those tissues with lower numbers of mitochondria, like skin and tendons, that tend to be more superficial, respond best to lower energy dosages. To ensure safe and effective treatments LFT devices provide guidelines for Fluence (dosing ) of different pathological presentations. 38 Furthermore, it is important to recognize that PBM is challenged by energy loss that occurs as light enters the skin and travels from superficial to deeper tissues. At the skin’s surface this is primarily due to reflection and below the surface by absorption from different tissues competing for different wavelengths of light. Proper configuration of the laser is a key factor in getting sufficient energy to target tissues. EU Medical Device classification is based on risk PHOTOBIOMODULATION DOSING A drug free, surgery free, non-invasive pain treatment alternative Fluence (dosage) is measured in J/cm2 in High Intensity (HI) PBMT devices. What we have learnt from Low Level Laser research is that outcomes are dosage dependent. 37
LASER classes - what do they mean? Laser devices are classified by the FDA according to their output power. For Photobiomodulation there are two common classifications:
•
Lightforce Therapy devices are classified as Class IIa, low risk
Factors that impact dose delivery at depth • Wavelength • Irradiance (power & beam area) • •
Laser classes - what do they mean? Lasers are classified by the FDA according to their output power. In the field of photobiomodulation therapy, there are two common laser classifications: • Currently all other Class IV HI PBMT devices are classified Class IIb, moderate risk • Class IIIb, Maximum power output of 0.5 watts • Class IV, Maximum power output of over 0.5 watts This means that Lightforce Therapy devices are a safe HI PBMT device
Class IIIb that have a maximum power output of 0.5W (typically 0.2-0.3W) Class IV that have power over 0.5W
Both classifications require both the user and patient to wear protective eyewear during emission
• Mechanism of delivery (contact vs. non-contact) • Treatment time • Size of treatment area • Type of tissue
Both Class IIIb and Class IV lasers require that safety eye protection be worn during emission.
The impact of power on treatment time Power is a key factor when delivering a therapeutic dose to deep target tissues. Not only do LightForce® lasers have higher output powers, but they also have larger beam areas, making them more capable of delivering a therapeutic dose to larger treatment areas. For example, to effectively treat a 300 cm 2 thoracic spine at 10 J/cm 2 , 3,000 joules of energy are required at the surface of the skin to deliver a therapeutic dose at depth. How long would that treatment take with a Class IIIb laser vs. a Class IV laser? For example, for treating a large area, such as the lower back, around 300cm 2 at 10J/cm 2 requires a total of 3000J. Compare the treatment times for a typical, single probe, LLLT device (2mW) and a 25W Lightforce device The impact of Irradiance (W/cm 2 ) on treatment time and therapeutic penetration Irradiance is a key factor when delivering a therapeutic dosage to deep target tissue. The power (W) of a device is spread over an area determined by the beam size. Not only do Lightforce Therapy devices have high power but also a large beam size. This means that they are capable of delivery more photons to deeper structures and larger areas, providing faster treatment times
Class IIIb 3,000 J at 0.5 W = 100 min Class IIIb 3000J at 0.2W = 250 minutes
Class IV 3,000 J at 15 W = 3.3 min Class IV 3000J at 25W = 2 minutes
17
Made with FlippingBook - PDF hosting