Continuous Wave Vs Pulsed

Penetration Depth

Low Level Laser Therapy (LLLT) often referred to as Photobiomodulation is used to increase tissue regeneration and wound healing, as well as to relieve pain and inflammation.

Whilst is is widely accepted that laser wavelength is one of the most important criteria in regards to penetration depth, with Infrared Wavelengths (eg 808nm, 830nm, 904nm etc) being the best, there are differences of opinion as to whether Continuous Wave (CW) Vs Pulsed laser light produces the best results.

The VetLaser 3000 comes with CW and 7 Pulsed Nogier frequencies, thus providing the user with the best of both worlds.


Advantage of Pulsed Lasers – Nogier Frequencies

There are many potential benefits of using Pulsed Lasers to treat injuries.  As there are pulse OFF times, followed by pulse ON times, less tissue heat is generated.  In order to deliver deep penetration, increased laser output powers are needed, in order to provide adequate energy (dose) to the damaged tissue.  If a CW was used, this increases the chance of tissue heating.

The Pulsed Laser can penetrate deeper into muscle tissue without the concern of tissue heating being an issue.  This thereby improves the laser’s ability to penetrate deep into muscle tissues obtaining deeper penetrating depths.

Researchers often claim that pulsed lasers penetrate deeper into tissue than CW lasers of the same average power.

It is important to remember that many LLLT applications do not require deep perpetration such as joint pain and tendinopathies.  Deep penetration is required to reach, neck, back and hip joints.

For tissue >5cm below the skin, research indicates that this is most likely achieved using Pulsed Lasers. Relief is brought by attenuating pain perception, rather than decreasing inflammation.

Research indicates that a higher fluence is required to alleviate pain, whereas a lower fluence decreases inflammation.


Studies Comparing Continuous Wave Vs Pulsed Laser Therapy

Studies conduced by researchers indicate that Pulsed wave laser therapy units can be more effective than CW lasers.  The conditions treated were wound healing and pain.  Pulsed lasers can also promote bone healing.  Tensile strength is also improved.

In the Continuous Wave Vs Pulsed Laser Therapy debate, there is significant literature highlighting the benefits of both technologies.  It often depends upon the condition treated as to which frequency is best to use.

Continuous Wave Light

Many practitioners consider CW lasers to be superior for LLLT applications. There is ample evidence to suggest that pulsed laser therapy may be superior to CW therapy, with all things being equal.  This is particularly the case with wound healing.

The logic being the research indicates that cells require periods of rest, before additional laser treatment.  Without this rest, they are unable to be stimulated any further.

The important parameters are crucial to consider when using laser therapy: Wavelength, frequency, peak power density, average power, energy density and duty cycle.

It is generally agreed that pulsing lasers play an important part in LLLT, where applications require deep tissue penetration.

The following YouTube video takes you through operating the VetLaser 3000 in Pulsed Mode.

Class 3B Cold Laser