Parameter estimation and model reduction for model predictive control in retinal laser treatment

Purpose Subdamaging thermal retinal laser therapy has the potential to induce regenerative stimuli in retinal diseases, but validated dosimetry is missing. Real-time optoacoustic temperature determination and control could close this gap. This study investigates a first in vivo application. Methods Two iterations of a control module that were optically coupled in between a continuous-wave commercial laser source and a commercial slit lamp were evaluated on chinchilla rabbits. The module allows extraction of the temperature rise in real time and can control the power of the therapy laser such that a predefined temperature rise at the retina is quickly achieved and held constant. Irradiations with aim temperatures from 45°C to 69°C were performed on a diameter of 200 µm and a heating time of 100 ms. Results We analyzed 424 temperature-guided irradiations in nine eyes of five rabbits. The mean difference between the measured and aim temperature was −0.04°C ± 0.98°C. The following ED 50 values for visibility thresholds could be determined: 58.6°C for funduscopic visibility, 57.7°C for fluorescein angiography, and 57.0°C for OCT. In all measurements, the correlation of tissue effect was higher to the temperature than to the average heating laser power used. Conclusions The system was able to reliably perform temperature-guided irradiations, which allowed for better tissue effect control than simple power control. This approach could enhance the accuracy, safety, and reproducibility of thermal stimulating laser therapy. Translational Relevance This study is a bridge between preclinical ex vivo experiments and a pilot clinical study.

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Parameter estimation and model reduction for model predictive control in retinal laser treatment

Cited by 5 publications

References 19 publications

Optimizing Computational Complexity in MPC with Lagrange Polynomial-Based Data Reduction

Optimizing Computational Complexity in MPC with Lagrange Polynomial-Based Data Reduction

State and Parameter Estimation for Retinal Laser Treatment

Real-Time Temperature-Controlled Retinal Laser Irradiation in Rabbits

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