Miniaturized laser scanner for endoscopic surgery

In minimally invasive laser surgery procedures, establishing direct line of sight from outside the patient to the surgical site is often difficult (if not impossible). In such cases, fiber-coupled lasers are employed. This contributes to expand the accessibility of the surgical sites, but has a significant impact on the quality of the laser-tissue interactions: laser ablations are wider and tissue carbonization (thermal damage) is high. These side effects are unacceptable for delicate operations such as vocal cord microsurgeries.

 

To tackle this issue and significantly enhance the quality of endoscopic laser microsurgeries, we are developing miniaturized laser scanner technologies. Our devices enhance fiber-based laser-tissue interactions by: 1) scanning the laser beam to allow better tissue relaxation, and 2) focusing the laser beam to enable non-contact fine tissue ablations.

 

The unique enabling technology of our miniature laser scanners is magnetic actuation. Local low-intensity electromagnetic fields are created inside the device to actuate the surgical laser fiber. This constitutes a robust solution, enabling precise laser manipulation and accurate execution of high-speed scanning motions for top-quality tissue ablations.

 

In addition, our miniature laser scanners feature custom optical systems that allow precise non-contact tissue ablations. This allows the achievement of ablation widths smaller than the fiber core diameter, and also allows non-contact operation, contributing to further improvements in precision and quality.

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Concept of the magnet laser scanner for endoscopic applications

 

A first research prototype of such system is shown in the video below. It measures 10 mm in diameter, offers a 4x4 sq.mm scanning workspace at a 20mm range, and can control the laser spot with 35µm precision.

Magnetic laser scanner prototype scanning a circular trajectory

 

The system is fully computer controlled. This enables real-time teleoperation and intraoperative planning, as possible with our CALM and Virtual Scalpel systems.

 

Teleoperation of the magnetic laser scanner

 

Magnetic Scanner for CO2 Lasers

CO2 lasers are currently the optimal lasers for soft tissue microsurgeries. This is due to their high absorption coefficient in water, which enables quality ablations with controllable superficial effects.

 

CO2 lasers cannot be coupled to standard optical fibers, requiring the use of special waveguides for flexible transmission. Therefore, to test the benefits of our magnetic laser scanner with this state-of-the-art laser, we developed updated prototype compatible to this laser wavelength.

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Miniaturized magnetic laser scanner for CO2 lasers

Preliminary results demonstrate the new miniaturized magnetic laser scanner for CO2 lasers enables significantly improved laser ablation quality when compared to the use of the bare waveguide (which is the current practice in the operating room for operations that do not require extreme precision and quality).

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Results from preliminary comparative trials highlighting the benefits of the miniaturized CO2 laser scanner in terms of ablation width and carbonization level

 

Ablation trial with our miniaturized CO2 laser scanner tool

 

 Related Publications

  1. [Patent] Mattos, L., Olivieri, E., Caldwell, D., “Distal scanning module, in particular to control the aiming and the movement of an optical apparatus of a medical device, such as a diagnostic or surgical instrument,” Patent numbers: IT TO2013A000943, PCT/IB2014/066127, US 10,045,684, November 20th, 2013 EU patent, US patent
  2. Acemoglu, A., Pucci, D., Mattos, L., “Design and Control of a Magnetic Laser Scanner for Endoscopic Microsurgeries,” IEEE/ASME Transactions on Mechatronics, vol. 24(2), pp. 527-537 https://doi.org/10.1109/TMECH.2019.2896248, April 2019
  3. Acemoglu, A., Deshpande, N., Mattos, L., “Towards a Magnetically-Actuated Laser Scanner for Endoscopic Microsurgeries,” Journal of Medical Robotics Research, Vol. 3, No. 2, http://dx.doi.org/10.1142/S2424905X18400044, February 2018
  4. Acemoglu, A., Mattos, L., “Non-Contact Tissue Ablations with High-Speed Laser Scanning in Endoscopic Laser Microsurgery,” 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC 2018), pp. 3660–3663, https://doi.org/10.1109/EMBC.2018.8513055, Honolulu, HI, USA, July 17-21, 2018
  5. Acemoglu, A., Deshpande, N., Mattos, L., “A Magnetic Laser Scanner for Non-Contact Endoscopic Ablations,” Hamlyn Symposium on Medical Robotics, June 2017
  6. Acemoglu, A., Mattos, L., “Magnetic Laser Scanner for Endoscopic Microsurgery,” Proceedings of the 2017 IEEE International Conference on Robotics and Automation (ICRA 2017), pp. 4215-4220, https://doi.org/10.1109/ICRA.2017.7989485, Singapore, May 2017
  7. Acemoglu, A., Mattos, L., “Characterization of Magnetic Field for Scanning Laser Module,” 5th Joint Workshop on New Technologies for Computer/Robot Assisted Surgery (CRAS 2015), Brussels, Belgium, September, 2015