Precision of Non-invasive Temperature Measurement by Diffuse Reflectance Spectroscopy

1995 ◽  
Vol 406 ◽  
Author(s):  
Zhongze Wang ◽  
Siu L. Kwan ◽  
T. P. Pearsall ◽  
James Booth ◽  
Barrett T. Beard ◽  
...  

AbstractWe demonstrate the use of diffuse reflectance spectroscopy as a non-invasive probe for measurement of temperature in real time on Si and GaAs substrates during semiconductor processing. Our results show that the standard deviation of the non-invasive optical technique is less than 0.7 °C for GaAs over the temperature range 50 °C < T< 600 °C with 5-second updates. These results support the notion that non-invasive optical temperature measurement can be used in semiconductor processing with a precision exceeding that of a thermocouple.

1995 ◽  
Vol 66 (10) ◽  
pp. 4977-4980 ◽  
Author(s):  
T. P. Pearsall ◽  
Stevan R. Saban ◽  
James Booth ◽  
Barrett T. Beard ◽  
S. R. Johnson

2012 ◽  
Author(s):  
Chandra Sekhar Prasanth ◽  
Joseph Betsy ◽  
Narayanan Subhash ◽  
Jayaraj L. Jayanthi ◽  
Janam Prasanthila

2021 ◽  
Vol 108 (Supplement_9) ◽  
Author(s):  
Scarlet Nazarian ◽  
Ioannis Gkouzionis ◽  
Michal Kawka ◽  
Nisha Patel ◽  
Ara Darzi ◽  
...  

Abstract Background Diffuse reflectance spectroscopy (DRS) is a technique that allows discrimination of normal and abnormal tissue based on spectral data. It is a promising technique for cancer margin assessment. However, application in a clinical setting is limited by the inability of DRS to mark the tissue that has been scanned and its lack of continuous real-time spectral measurements. This aim of this study was to develop a real-time tracking system to enable localisation of the tip of a handheld DRS probe to aid classification of tumour and non-tumour tissue. Methods A coloured marker was attached to the DRS fibre probe and was detected using colour segmentation. A Kalman filter was used to estimate the probe’s tip position during scanning of the tissue specimen. In this way, the system was robust to partial occlusion allowing real-time detection and tracking. Supervised classification algorithms were used for the discrimination between tumour and non-tumour tissue, and evaluated in terms of overall accuracy, sensitivity, specificity, and the area under the curve (AUC). A live augmented view with all the tracked and classified optical biopsy sites were presented, providing visual feedback to the surgeons. Results A green coloured marker was successfully used to track the DRS probe. The measured root mean square error of probe tip tracking was 1.18±0.58mm and 1.05±0.28mm for the X and Y directions, respectively, whilst the maximum measured error was 1.76mm. Overall, 47 distinct sets of tumour and non-tumour tissue data were recorded through real-time tracking of ex vivo oesophageal and gastric tissue. The overall diagnostic accuracy of the system to classify tumour and non-tumour tissue in real-time was 94% for stomach and 96% for the oesophagus. Conclusions We have been able to successfully develop a real-time tracking system for a DRS probe when used on stomach and oesophageal tissue for tumour detection, and the accuracy derived demonstrates the strength and clinical value of the technique. The method allows real-time tracking and classification with short data acquisition time to aid margin assessment in cancer resection surgery.


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