Surgical CO2 Lasers

White Paper

© Luxarcare LLC, 2008

 

Contents

 

·       Foreword

·       Introduction

·       Surgical CO2 laser's building blocks

·       State-of-the-art American technology

·       How do imported lasers compare to American-made lasers?

·       How important a built-in laser power meter is for a surgical laser?

·       ‘Internal calibration’

·       Laser cooling technology

·       Beam delivery technology

·       Laser tube technology

·       Laser Warranty

·       International Laser Safety Compliance Certifications

·       Conclusion

·       Appendix

 

Foreword

LuxarCare has been receiving numerous offers from several overseas surgical laser manufactures and importers to distribute and service their products in the USA and Canada. We studied such offers very seriously; we have inspected and evaluated five different imported surgical lasers that we have acquired as trade-ins during 2006-08.

In this white paper we describe the differences between the state-of-the-art American made surgical CO2 lasers and imported (e.g. Chinese made, etc.) lasers. We present our findings and reasons why we do not recommend any of the inspected imported lasers neither to any Luxarcare customers nor any other surgeon in North America.

Introduction

Thousands of veterinarians around the globe are adopting state-of-the-art CO2 laser surgery that is in high demand by their clients - the pet owners. Laser surgery brings tremendous clinical benefits to patients and also rewards with a very substantial additional revenues not available otherwise.

Ironically, and largely unknown to general public, North American veterinarians are being persuaded by countless importers and resellers into purchasing low-quality clones of antiquated and repackaged glass tube, articulated arm surgical CO2 lasers of older American designs from the 1980's.  

At the same time, high-quality state-of-the-art American made lasers (new www.aesculight.com and www.lightscalpel.com) are making a strong comeback after a devastating series of Mergers and Acquisitions in Medical Laser Industry during 1997-2000, that have nearly decimated the surgical CO2 lasers' manufacturing base in North America when all three major American surgical CO2 laser manufacturers Surgilase, Luxar and Coherent Medical were purchased and shut down by Lumenis by 2001.

One could only wish that more North American veterinarians would evaluate American made lasers too when considering to purchase surgical lasers for their practices - the difference in technology and quality between the imported (mostly Chinese) and American-made lasers is vast.

Laser handpiece. The difference between old and new laser technologies is vast

Figure 1. The difference between old and new technologies is vast

Surgical CO2 laser's building blocks

For decades, the CO2 Laser undisputedly remains the Gold Standard of surgical lasers because of its unique wavelength, versatility, precision and mature technology. Tens of thousands of surgical CO2 Lasers are used daily across North America in various specialties at veterinary and human medical facilities. Consider the world’s most popular surgical CO2 laser - Luxar’s LX-20 series with the first ever flexible waveguide fiber beam delivery (www.luxarcare.com). This brand has the largest installed base (over 12,000 units), which testifies to its design as one of the best and the safest. This laser's design includes - see Figure 2 - the following critical components:

1       all-metal laser tube;

2       low voltage 32 Volts DC and RF power supplies;

3       heat exchanger;

4       beam delivery system;

5       laser power meter;

6       beam attenuator - shutter;

7       devices monitoring the performance of all critical components 1 thru 6 above;

8       user control panel;

9       software program controlling all the hardware items 1 thru 8 above; and

10    safety ‘watch-dog’ software program monitoring items 1 thru 9 above.

Among the only negative features of Luxar laser design are the antiquated (1994 design) user control panel, limited average CW and SuperPulse laser powers (20 Watt and 10 Watt respectively) and inefficient heat exchanger (relying on natural air convection).

Luxar Surgical Laser Features

Figure 2. Luxar's 20 Watt surgical CO2 laser.  The best selling surgical lasers during 1995-2005

State-of-the-art American technology

Consider the next generation of flexible fiber surgical CO2 lasers - Aesculight AE-10 and AE-20 ranging in power from 12 to 50 Watts (see Figure 3). Designed by many former Luxar laser engineers currently employed with LightScalpel / Aesculight, these lasers feature similar set of critical components 1 thru 10 above. Unlike the Luxar laser, Aesculight lasers feature a far more powerful laser source (up to 50 Watt regular CW operation and 30 Watt SuperPulse mode) and an exclusive highly efficient active cooling heat exchanger. All models are covered by 3 year 'bumper-to-bumper' warranty. Among new features is unique touch-screen user control panel allowing for custom controls over laser, smoke evacuator, air purge, READY mode time-out delays, and user defined custom laser power settings. The icing on the cake is Aesculight built-in digital compendium of over 100 surgical laser procedures including text, images and videos. Aesculight lasers are sold as scalable and upgradeable surgical platform allowing for inexpensive future upgrades for just a price difference between the two respective models.

Aesculight Surgical Laser features

Figure 3. Aesculight 50 Watt surgical CO2 laser. The only American made veterinary surgical CO2 laser

How do imported lasers compare to American-made lasers?

We have inspected five different imported surgical lasers that we have acquired as trade-ins during 2006-08: two Korean-made lasers (one of which is shown in Figure 4) sold by Union Medical Laser; two Chinese-made table-top lasers shown in Figure 5 distributed by Union Medical Laser, Cutting Edge Surgical Lasers and other importers; and one imported Italian made laser shown in Figure 6 sold by Cutting Edge Surgical Lasers.

All five imported trade-in laser feature bulky antiquated (1980's technology) articulated arms and antiquated fragile high voltage (over 10,000 Volts) glass laser tubes (1960s technology) with flowing liquid required to prevent the glass from cracking under the intense heat generated by the plasma inside the glass tube.

Upon inspecting the laser shown in Figure 4, it was discovered that it was missing the beam attenuator (or shutter) and the laser power meter. And yet, in 2000 this laser model was cleared by the FDA for use on human patients in spite of the fact that FDA's own regulations (CFR Title 21 Part 1040) mandates both the beam attenuator and the laser power meter to be an integral part of a medical laser.  Upon inspecting yet another Korean-made trade-in laser, similar to the one shown in Figure 4, it was discovered that beam shutter and laser power meter were also missing in its design. Our conclusion is that:

1                 These inspected imported lasers are unsafe for any medical, veterinary or industrial users (due to missing beam attenuator - shutter), and

2                 FDA was wrong clearing these imported lasers for medical use (due to missing power meter and shutter).

Upon inspecting two lasers shown in Figure 5, it was discovered that they do have the beam-attenuator (shutter); however safety devices monitoring and verifying the performance of the shutter are absent.  Also absent in these imported lasers is the laser power meter.

Upon inspecting the laser shown on the right-hand side in Figure 6, it was discovered that both the laser power meter and the beam attenuator (shutter) are present, as well as shutter monitoring safety devices.

Korean surgical laser features

Figure 4. Imported 25 Watt surgical CO2 laser. Model UM-L25 (and similar private labeled imports) is distributed in USA and Canada by Union Medical Laser and others

Chinese surgical laser features

Figure 5. Imported table-top surgical CO2 lasers.
Left - this and similar models are imported into USA and Canada by Union Medical Laser (UM-L15) and Cutting Edge Surgical Lasers and many other importers. Right - an older variation of the laser shown on the left; it is still being sold in the USA and Canada by many importers

American made vs. imports medical CO2 lasers

Figure 6.  Side by side comparison of all-metal tube fiber waveguide CO2 laser:
Aesculight vs. imported glass-tube articulated arm laser distributed in the USA and Canada by Cutting Edge Surgical Lasers and other importers

How important a built-in laser power meter is for a surgical laser?

FDA regulations require laser power meter on medical lasers and do not require presence of laser power meter on non-medical laser (FDA CDRH Title 21 Part 1040.11 defines 'medical laser' as such used on humans). However, veterinary laser surgeons would surely understand that accurate control of laser power affects such important aspects of laser surgery as thermal damage to and charring of the soft tissue.  Therefore, those veterinarians who own imported lasers shown in Figures 4 and 5 might not feel comfortable knowing that such lasers are not safe enough for use on human patients, and yet such lasers are used on animal patients.

 'Internal calibration'

One can certainly appreciate the joke in the claims by some importers that their glass tube, articulated arm lasers can be 'internally calibrated'. This is simply technically impossible for lasers shown in Figures 4 and 5 since these lasers don't have the laser power meter to measure the laser power with! Even though the more expensive imported laser in Figure 6 does include an on-board laser power meter, there is nothing in its design for the end-user to verify the integrity and functionality of the seven mirror articulated arm: the alignment and the integrity of all seven mirrors can only be verified at the factory or by the trained field service engineers.

Laser cooling technology

Notably missing on lasers shown in Figures 4 and 5 are the heat exchangers. The CO2 laser is only 10-20% efficient; hence 80-90% of electrical energy is transformed directly into the heat inside the laser tube and the laser system. This waste heat needs to be removed, otherwise the laser overheats and the laser power deteriorates during operation.  Since lasers shown in Figures 4 and 5 do not heat exchangers, these lasers cannot be operated for extended period of time without overheating and subsequent laser power deterioration!  Ironically, designers of lasers shown in Figures 4 and 5 have made laser overheating and laser power deterioration a 'non-issues' by simply removing laser power meter! Why bother measuring laser power!

Beam delivery technology

Flexible fiber waveguide lasers shown in Figures 2 and 3 became dominant technology since mid-1990s. Rugged and long-lasting flexible fibers enable compact and ergonomic handpieces to have scalpel-like feel and featuring pin-point accuracy as well as enhanced flexibility and accessibility for surgeons. On the contrary, articulated arms shown in Figures 4, 5 and 6 are an old technology (developed during 1970s - 1980s) and are in use by surgical CO2 laser manufacturers who do not have access to new proprietary flexible fiber waveguide technology. Besides convenience of using flexible fiber vs. bulky articulated arms, the flexible fiber has an added safety benefit and advantage: fiber can be conveniently and inexpensively calibrated at any time by the user. The articulated arm can only be calibrated at the factory or by trained field service engineers.

Laser tube technology

Rugged and reliable all-metal RF excited CO2 laser technology is the dominant technology in medical (tens of thousands installations) and industrial (hundreds of thousands installations) laser applications in power range from 10 - 500 Watts.  This is the ONLY proven and reliable technology allowing for fast and inexpensive service in highly demanding (24-7-365) industrial settings for cutting, welding, engraving, printing, marking and coding etc. Since all-metal technology is almost exclusively owned and manufactured by USA-based companies (including LightScalpel and Aesculight), it is not available to the importers of lasers shown in Figures 4, 5 and 6. In contrast to all-metal CO2 lasers, antiquated fragile glass tubes (1960s technology) are difficult to service and they cannot operate without flowing liquid needed to prevent the glass from cracking under the intense heat generated by electric discharge plasma inside the laser tube. A very high voltage, over 10,000 Volts, is required to operate plasma in such glass tubes; this very high electrical voltage presents a unique liability issue for laser service companies and their personnel.  Neither eroded electrodes nor metal sputtered glass tube walls are serviceable - which often necessitates laser tube replacement rather than repair! These and many other reasons (difficulties with glass tube plasma pulsing and turning on, severe limitations on laser pulse width, laser power stability, laser beam quality, etc) have allowed all-metal lasers to replace glass tube lasers in virtually all industrial and most medical applications since mid-1990s.

Laser Warranty

Some of the imported lasers, such as shown in Figures 4 and 5, have laser power monitoring and other safety features simply disabled; this allows importers to claim an arbitrary long warranty period, since laser tube performance is not being monitored. As a result, the so called 'warranty' for some imported lasers is often meaningless. Worth noting that the manufacturer of the more expensive glass tube laser shown in Figure 6 provides an on-board laser power meter and its warranty is only 1 year. In contrast, the cheaper glass tube laser shown in Figure 4 is sold with up to 5 years of warranty - the most likely explanation is that this laser simply lacks the laser power meter to even detect any deterioration of the laser tube power; one might wonder why its warranty is not 10 or 50 years since such warranty won't be affected by laser tube performance deterioration!

International Laser Safety Compliance Certifications

Some importers misrepresent their products as compliant with relevant international safety regulations. For instance, one Chinese manufacturer is representing its surgical CO2 lasers as a CE certified product - see Figure 7. Upon closer examination, however, one can easily uncover that 1) CE standards EN 60335-1 and 60335-2-23 quoted in such certificate are only applicable to HOUSEHOLD appliances such as curling combs and irons, hair- and hand-dryers, etc; and 2) quoted CE standards explicitly declare that they are not applicable to any 'appliances intended for medical use'. Sadly enough, there are numerous importers in North America already peddling these and other similar devices to many thousands of unsuspecting American veterinarians.

Chinese-made CO2 laser's  Attestation certifying that it conforms to European Union (CE) standards for HOUSEHOLD appliances such as hair-dryers 

Figure 7.  Chinese-made CO2 laser's  'Attestation' certifying that it conforms to European Union (CE) standards for HOUSEHOLD appliances such as hair-dryers

Conclusion

One could only wish that more North American veterinary surgeons will recognize some of the foreign made glass-tube, articulated arm surgical lasers for what they truly are: poorly and sometimes unsafely (e.g. imported laser shown in Figure 4) repackaged clones of antiquated and outdated designs from 1980's.

Appendix

Surgical lasers comparison chart

Figure 8.  The summary of specifications of American-made and some imported surgical CO2 lasers