Spectroscopic characterization of tissue and liquids during arthroscopic radio-frequency ablation

Radio-frequency ablation devices generating a local plasma are widely used as a safe and precise tool for tissue removal in arthroscopic surgeries. During this process, specific light emissions are generated. The aim of this study was to investigate the diagnostic potential of optical emission spectrum analysis for liquid and tissue characterization.

The emissions in different saline solutions and during porcine tendon, muscle, and bone tissue ablation were recorded and analyzed in the range of 200-1000 nm.

Specific atomic lines (Na, K, Ca, H, O, W) and molecular bands (OH, CN, C2) were identified, originating from compounds in the liquids and tissues in contact with the probe. A linear correlation between the concentration of both Na and K in solution with the intensities of their spectral lines was observed (Na: R²  = 0.986, P < 0.001; K: R²  = 0.963, P < 0.001). According to the Wilcoxon rank-sum test, the Ca- and K-peak intensities between all three tissue samples and the CN-peak intensities between muscle and bone and tendon and bone differed significantly (P < 0.05).

These findings prove the general feasibility of spectroscopic analysis as a tool for characterization of liquids and tissues ablated during radio-frequency ablation. This method can potentially be further developed into an intraoperative, real-time diagnostic feature aiding the surgical team in further optimizing the procedure.