Behind the Beam: Power Considerations for Medical Lasers

Since the invention of the first laser more than 60 years ago, laser technology has been harnessed for a wide range of applications. When compared with other electromechanical mediums, lasers offer levels of precision, power, and versatility that make them highly preferred for critical and precise use cases. In medical procedures, for example, laser-based treatments offer patients a minimally invasive option to address various health disorders. 

Maximizing the benefits of these powerful tools requires the combined expertise of medical practitioners, device makers, and power design engineers as laser-based medical technology presents unique power challenges. The correct power supplies in a laser for medical use can mean the difference between brilliant new applications and complicated hazards.

The Role of Lasers in Modern Medicine 

In terms of medical applications, lasers can be used to treat conditions such as nonmelanoma skin cancers, the shrinking or destruction of tumors, and polyp removal. Laser technology, due to its highly directional precision, is also commonly used to remove unwanted or abnormal blood vessels in the skin. In cases that require lasers to come in contact with a patient either externally or internally, lasers need to be finely tuned.

Surgical processes don’t call for the high-power outputs that industrial-based applications require as there is, of course, a stark difference between cutting steel and treating a patient. Due to the narrower beams emitted in medical laser devices, medical use cases require highly sensitive frequencies.

As a result, applications in the medical space require unique power supplies to properly dictate the necessary output of pulse width, frequency, amplitude, and other specifications. Interestingly, like the adage that no two snowflakes are alike, no two applications of lasers in the medical space are the same.

YAG lasers are often used for LASIK procedures, removal of lesions, or trans myocardial revascularization. FG TRADE/ISTOCK/GETTY IMAGES PLUS VIA GETTY IMAGES

Examples of how lasers are utilized in medical treatments include:

Navigating Unique Power Supply Requirements 

While laser design is typically unique to the manufacturer, ensuring that the power supply can be set and controlled by the operator is paramount to maximize the efficacy of the laser and help ensure proper functionality. Inherently, lasers must be well supported by their power supplies to reliably energize the gain medium. The corresponding output has its own specific frequencies that are unique to a predetermined application. When using lasers for medical procedures, incorrect power frequencies could result in making incisions that aren’t deep enough or are too wide, causing potentially catastrophic results when working on human tissue.  

As there is virtually no acceptable margin of error when it comes to treating patients, lasers for medical applications must be finely tuned, maintained, and operated at the correct frequency and power. The unique and sometimes life-saving applications have a range of power considerations that must be considered, including power design flexibility and noise reduction.   

Applications for CO2 lasers include skin resurfacing and rejuvenation, gynecological surgery, dental surgery, and veterinary medicine. VLG/ISTOCK/GETTY IMAGES PLUS VIA GETTY IMAGES

Laser Choice Based on Use Cases, Power Design Flexibility, and Noise Reduction 

In medical applications, depending on the procedure, the unique features and characteristics of specific types of lasers dictate their respective use cases. Due to their ability to deliver precise, versatile thermal energy that is minimally invasive, CO₂ and Yttrium Aluminum Garnet (YAG) lasers are commonly used in medical procedures. Applications for CO₂ lasers include skin resurfacing and rejuvenation, gynecological surgery, dental surgery, and veterinary medicine, while YAG lasers are often used for LASIK procedures, removal of lesions, trans myocardial revascularization, and breaking down kidney or bladder stones.

As lasers become more complex, there will be a need for power design flexibility to support a range of alternate voltages for multiple, varying power output needs. For example, the power supply may need to provide both the power required for the laser to function optimally as well as to keep a health-check circuit alive. To support this, power supplies can be designed to deliver a required alternate voltage while also concurrently providing reliable power needed for the laser’s radiation source. In medical applications, lasers also have a specific requirement for isolation due to patient contact, which makes it critical that the frequency control of the power supply has high fidelity. 

Due to heat rejection and the extensive amount of cooling that laser systems require, lasers can be relatively inefficient and noisy machines when in use. The noise associated with the cooling process can also detract from the benefits of using lasers in medical environments by distracting the efforts of surgeons and support staff in the treatment of patients. In such cases, increased fan speeds or the utilization of conduction cooling can help dissipate heat while reducing noise.

With spectroscopy, lasers can make light interact with biological tissue to obtain information about the nature and state of diseases. SURIPHON SINGHA/ISTOCK/GETTY IMAGES PLUS VIA GETTY IMAGES

Precision, Progress, and Patient Care 

When treating patients, lasers enable surgeons to accomplish more complex tasks, curtail blood loss, and reduce the chance of infection. Lasers will continue to have a diverse and enduring presence in medical applications due to their high reliability, precision, and ability to yield consistent results. 

By fine tuning power supplies to meet individual application needs, power design engineers can help medical practitioners successfully utilize these powerful tools to deliver positive outcomes for patients.