Contributed by Ren Houyoux, LVT
As the veterinary community is quickly learning, the applications for photobiomodulation therapy (PBMT) are nearly as varied as the different types of injuries and diseases we see in the patients who walk through our doors. To accommodate the rapidly growing range of uses for this technology, the market needed a delivery platform flexible enough to be used in a myriad of settings, species, and conditions. To satisfy this need for clinical versatility, Companion Animal Health developed
the Empower Delivery System, which features four unique treatment head attachments, each designed to maximize therapeutic benefit, no matter what condition or animal you may be treating.In this blog post we will discuss best practices for choosing attachments, including how to inspect them for defects prior to use and how to ideally match them based on their intended use. We will also discuss the optical properties of each attachment head, specifically the divergence (widening) that occurs and the corresponding impact on treatment.
Pre-Treatment Attachment Inspection
At all times when treating with laser therapy, we must ensure that the treatment head lens is clean and intact. Before starting each treatment, you should ensure there is an even beam spot visible from the aiming beam. If there is debris, hair, blood, oils, or any other foreign material on the surface of the lens, it has the potential to alter the laser beam as it is emitted. We recommend using a 70% isopropyl alcohol solution to clean these lenses, and then immediately drying them with a lint-free cloth or Kim wipes (not scrubs, paper towels, gauze, or other materials as they could cause a surface hazing to eventually develop over time).
Additionally, any damage to the lenses, such as fissures, cracks, pitting, surface blemish, hazing of the surface, or any other physical degradation could alter the laser beam. A damaged attachment must be immediately replaced if there are any signs of degradation.
Proper Attachment Selection
The primary factor to consider when selecting an attachment is the intended use. So, the size of the treatment area and the condition to be treated must both be taken into account. When tolerated and/or appropriate based on the condition being treated and patient response, laser therapy should be applied directly to the skin (or fur coat) using an “on-contact” treatment method, as there are multiple advantages of using an on-contact technique. With an on-contact technique, the deep tissue applicators should be used.
When operating the laser unit with an off-contact technique, the flat lens cone attachments should be used. With an off-contact technique, the attachment should be held over the tissues at about a distance of 1” – 3”. The cone attachments should NEVER come close or make contact with tissues. Also, the ‘hover distance’ from the tissues should be strictly adhered to when utilizing the cones, as the divergence could cause the beam to spread and expose unintended objects to the laser light.
Another important factor in treatment head selection is the power setting (measured in watts, abbreviated as W) at which the laser is set to operate. The small deep tissue and cone attachments are designed to be used at any power up to 3 W. Any time we are operating over 3 W, we need to be using the large deep tissue applicator or large cone attachment. This power range delineation is meant to account for irradiance (W/cm²), as well as to enhance both patient comfort and durability of the attachment.
The Effect of Divergence
Each treatment head lens has a specific effect on the laser beam as it is emitted though the lens and onto patient tissues. The widening (or “divergence”) of the beam as it is being emitted through the lens should be considered when treating to ensure proper energy delivery to target tissue. Thus, it is crucial that the operator be aware of each treatment head’s specific divergence and operate within the specified distance so as to prevent near-field objects from being exposed inadvertently.
The large deep tissue applicator has a divergence of only 3 degrees, so the beam emitted remains highly collimated. The small deep tissue applicator has a somewhat larger divergence of 13 degrees. Both cone (non-contact) attachments diverge the beam at a more extreme angle of 47 degrees. The operator’s understanding of the optical properties of each attachment is thus crucial in appropriate attachment selection, designing and carrying out valid, safe, and time-efficient treatments. The pictures below demonstrate this attachment-specific divergence as shown by the aiming beam when in ready mode or during beam emission.
Just like any other tool we have, we must utilize the PBMT unit the way in which it was designed to operate. Correct attachment selection is as important as appropriate technique (hovering at 2” above tissue surface with the cone applicators, not closer or further away) when using the laser therapy unit correctly. The variety of attachments provides the operator with fluidity in treatment applications and thus the ability to address a variety of conditions in an array of patient species.