The MLS® Difference – The Pulses

MLS®️ is an abbreviation of ‘Multiwave Locked System’ and refers to the unique technology which pairs 2 different wavelengths which are delivered in synchronicity. MLS®️ lasers emit 808nm and 905nm simultaneously to give quick, effective treatment reducing pain, inflammation and oedema.
With peak powers of 25W, 75W or an incredible 1kW across the range, one of the key differences in MLS®️ Laser Therapy vs other high-power lasers is the controlled thermal effect which allows for completely safe use and ease of mind. This is achieved through the use of 2 specific diodes.

The emission mode depends on the type and construction characteristics of the source. There are two kinds of emission: continuous and pulsed. MLS®️ utilises a true, pulsed diode to emit the more powerful 905nm (25W/75W peak power) wavelength and a continuous diode for the lower powered 808nm (1.1W peak power) emission.

Given that Power (watts) = Energy (joules) /Time (sec)

By squeezing energy delivery into short pulses, you can dramatically increase peak power outputs. For example 1 Joule delivered over 1 second gives 1 watt; 1 Joule delivered over 1 nanosecond gives 10,000,000 watts.

It is a basic distinction that a pulsed source normally cannot work in continuous mode (CW) and, vice versa, a continuous source cannot emit in pulsed mode (PW). Therefore, to generate a ‘pulse’ using a continuous emission diode, you need to repetitively interrupt the emission, generating a ‘continuous-interrupted’ (CW-I) emission and not a true pulse.

In terms of waveform, the difference between continuous-interrupted and pulsed mode is considerable. The pulsed emission can reach extremely high peaks of power in a very short pulse time and is able to convey the energy to deeper layers of tissue without the risk of exceeding the thermal damage threshold on the skin. Continuous-interrupted emission generated by continuous wave sources cannot reach the same peak power as pulsed sources. Moreover, a longer pulse duration also means less control of the thermal effect when medium-high power is employed. More often than not, incorrect terms are also used in a misleading way to define the emission mode, causing confusion among non-laser experts. Terms such as “Hyper Pulsed”, “Super Pulsed”, “Ultra Pulsed” and occasionally even “Pulsed” itself are misused to indicate the possible operating modes of continuous diodes like 810nm, 980nm or 1064nm. These specific emission modes are simply continuous-interrupted emissions, modulated by more or less high frequencies (up to dozens of kHz) or by different duty-cycles, but they have totally different properties from the real pulsed lasers, such as the pulsed diode 905nm or the pulsed Nd:YAG 1064nm.

Why is it advantageous to deliver a high peak power wavelength using a pulsed emission? High peak power is desirable to allow for quick treatment times and faster results for patients but as mentioned above, higher powers can have safety implications. With MLS®, the time between pulses (the ‘off’ times) allows any thermal energy which would otherwise build up in the tissues to dissipate from and to disperse more evenly through the tissues. There are a number of benefits to this, not least the ability to use the laser safely with no risk of thermal damage for your patients but also that the nanopulse technology allows us to hold the laser stationary, giving focussed treatment on painful areas and trigger points.

In the image above, you can see energy delivery in CW-I mode. The temperature builds each time the wavelength/energy is delivered at a higher power level as there is not enough ‘off’ time to allow that energy to dissipate. If CW-I Diodes are used at high powers, there is potential for harmful accumulation of heat in the tissues. The image below demonstrates Continuous Emission (known as CPW or ‘Continuous Pulsed Wave’ on MLS®️ lasers), with the same potential harmful overheating effects:

Here the 808nm wavelength is no longer interrupted and delivers a continuous stream of energy.

It is worth mentioning at this point, that although the 808nm diode in the MLS® Lasers is delivered in continuous or continuous-interrupted mode (FPW, Frequenced-Pulsed Wave’), it uses low peak powers that are safe in the tissue, and particularly effective against swelling and inflammation.

In the next image you can see true pulsed emissions which is applicable to the 905nm wavelength in MLS® laser. This powerful wavelength is always pulsed to ensure safe but powerful and effective delivery of treatment.

Tests carried out using the MLS®️ laser, held steady in one spot for 20 minutes demonstrate that the thermal threshold of 43C is not reached. At around 43°C desirable biological processes can be reversed and over 45°C there is a risk of thermal damage. High levels of heat are not desirable or necessary for effective therapeutic laser treatment.

When considering class 4 therapeutic laser devices, it is important to ask if the laser delivers a true pulsed emission or a continuous/frequenced method and consider the safety implications of this. Can you hold the laser stationary to target painful areas or do you have to keep it moving to negate the risk of thermal damage?

To find out more about the safe, effective MLS®️ range of therapeutic lasers, contact us at sales@celticsmr.co.uk