Feasibility study: protein denaturation and coagulation monitoring with speckle variance optical coherence tomography

Abstract

We performed the feasibility study using speckle variance optical coherence tomography (SvOCT) to monitor the thermally induced protein denaturation and coagulation process as a function of temperature and depth. SvOCT provided the depth-resolved image of protein denaturation and coagulation with microscale resolution. This study was conducted using egg white. During the heating process, as the temperature increased, increases in the speckle variance signal was observed as the egg white proteins coagulated. Additionally, by calculating the cross-correlation coefficient in specific areas, denaturized egg white conditions were successfully estimated. These results indicate that SvOCT could be used to monitor the denaturation process of various proteins.

Real-time co-localized OCT surveillance of laser therapy using motion corrected speckle decorrelation

“…In OCT, a given sub-resolution spatial distribution of scatterers with its associated scatterer size and refractive index yields a specific speckle pattern provided there are no intrinsic -such as diffusion-or extrinsic -such as bulk tissue motion-mechanisms affecting their configuration state [49]. However, as tissue undergoes photocoagulation, proteins denaturate, producing a change in the refractive index distribution and, therefore, a change in the coherent sum of individual back-scattered contributions resulting in a temporal evolution of the speckle pattern seen in the tomogram [31,32,39,50]. Lo et al observed that these variations slow down once the tissue has fully coagulated [29].…”

“…It has been used in identifying pathologies in the epithelium layer of different tissues, including some treatable with laser therapy, such as Barrett's esophagus [24][25][26]. Tissue coagulation produces changes in the acquired OCT tomograms which enable the use of OCT to monitor the progression of the coagulation process and determine treatment depth [27][28][29][30][31][32][33].…”

Selective retina therapy monitoring by speckle variance optical coherence tomography for dosimetry control

“…The svOCT has been extensively developed in recent years for OCT angiography, which is used to visualize retinal microvasculatures; 20 it has also been shown to be able to monitor protein denaturation and coagulation. 21 Thus, it is expected that svOCT could be an effective way to detect speckle variation changes induced by morphological and structural changes of retinal tissue during the thermal-induced microbubble formation and collapse by laser irradiation. In this paper, we studied and demonstrated SRT monitoring based on the svOCT.…”

Intraoperative Speckle Variance Optical Coherence Tomography for Tissue Temperature Monitoring During Cutaneous Laser Therapy

“…Speckle variance OCT (svOCT) has been developed and used for the visualization of microvasculature [22], [23]. Using a similar idea, Lee et al [24] were able to monitor protein denaturation and coagulation process with svOCT, which was based on the speckle pattern change due to tissue temperature change. Also, Lee et al [25] used an in-house built svOCT system integrated into a commercial ophthalmic laser system and analyzed the relationship between the average laser energy and peak intensity of the svOCT image during selective retina therapy.…”

“…In this study, we proposed to use svOCT to monitor the skin tissue temperature change during cutaneous pulsed laser therapy. This approach is based on previous work that shows the speckle variance values in OCT images directly relates to the tissue temperature change [24]. Thus, it is expected that the speckle variance value can represent the thermal induced molecular motion even when heated rapidly using a short-pulsed laser and still maintain a linear relationship with peak tissue temperature.…”