{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:16:14Z","timestamp":1760217374458,"version":"build-2065373602"},"reference-count":23,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2015,1,30]],"date-time":"2015-01-30T00:00:00Z","timestamp":1422576000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The detection of cancer at its earliest stage is crucial in order to increase the probability of a successful treatment. Optical techniques, specifically diffuse reflectance and fluorescence, may considerably improve the ability to detect pre-cancerous lesions. These techniques have high sensitivity to some biomarkers present on the tissues, providing morphological and biochemical information of normal and diseased tissue. The development of a chip sized spectroscopy microsystem, based on these techniques, will greatly improve the early diagnosis of gastrointestinal cancers. The main innovation is the detection of the spectroscopic signals using only few, but representative, spectral bands allowing for miniaturization. This paper presents the mathematical models, its validation and analysis for retrieving data of the measured spectroscopic signals. These models were applied to a set of phantoms clearly representative of gastrointestinal tissues, leading to a more accurate diagnostic by a pathologist. Moreover, it was demonstrated that the models can use the reconstructed spectroscopic signals based only on its extraction on those specific spectral bands. As a result, the viability of the spectroscopy microsystem implementation was proved.<\/jats:p>","DOI":"10.3390\/s150203138","type":"journal-article","created":{"date-parts":[[2015,1,30]],"date-time":"2015-01-30T10:08:29Z","timestamp":1422612509000},"page":"3138-3153","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Optical Microsystem for Analysis of Diffuse Reflectance  and Fluorescence Signals Applied to Early Gastrointestinal Cancer Detection"],"prefix":"10.3390","volume":"15","author":[{"given":"Sara","family":"Pimenta","sequence":"first","affiliation":[{"name":"Department of Industrial Electronics, University of Minho, Campus de Azur\u00e9m,  Guimar\u00e3es 4800-058, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5829-6081","authenticated-orcid":false,"given":"Elisabete","family":"Castanheira","sequence":"additional","affiliation":[{"name":"Centre of Physics (CFUM), University of Minho, Campus de Gualtar, 4710-057 Braga,  Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2460-0556","authenticated-orcid":false,"given":"Gra\u00e7a","family":"Minas","sequence":"additional","affiliation":[{"name":"Department of Industrial Electronics, University of Minho, Campus de Azur\u00e9m,  Guimar\u00e3es 4800-058, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2015,1,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"16227","DOI":"10.1364\/OE.16.016227","article-title":"Quantitative spectroscopic imaging for non-invasive early cancer detection","volume":"16","author":"Yu","year":"2008","journal-title":"Opt. Express"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1016\/j.jlumin.2005.12.015","article-title":"The color of cancer","volume":"119\u2013120","author":"Georgakoudi","year":"2006","journal-title":"J. Lumin."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1016\/j.copbio.2009.02.004","article-title":"Advances in quantitative UV-visible spectroscopy for clinical and pre-clinical application in cancer","volume":"20","author":"Brown","year":"2009","journal-title":"Curr. Opin. Biotechnol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1372","DOI":"10.1364\/OE.17.001372","article-title":"A strategy for quantitative spectral imaging of tissue absorption and scattering using light emitting diodes and photodiodes","volume":"17","author":"Lo","year":"2009","journal-title":"Opt. Express"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"30","DOI":"10.1136\/gut.52.suppl_4.iv30","article-title":"Improving endoscopic resolution and sampling: Fluorescence techniques","volume":"52","author":"Ell","year":"2003","journal-title":"Gut"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1620","DOI":"10.1053\/gast.2001.24842","article-title":"Fluorescence, reflectance, and light-scattering spectroscopy for evaluating dysplasia in patients with barrett's esophagus","volume":"120","author":"Georgakoudi","year":"2001","journal-title":"Gastroenterology"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1016\/S1011-1344(03)00025-3","article-title":"Endoscopic light-induced autofluorescence spectroscopy for the diagnosis of colorectal cancer and adenoma","volume":"70","author":"Mayinger","year":"2003","journal-title":"J. Photochem. Photobiol. B"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"025301","DOI":"10.1088\/2040-8978\/16\/2\/025301","article-title":"Distinguishing human normal or cancerous esophagus tissue ex vivo using multiphoton microscopy","volume":"16","author":"Liu","year":"2014","journal-title":"J. Opt."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"060505","DOI":"10.1117\/1.3041500","article-title":"Cost-effective diffuse reflectance spectroscopy device for quantifying tissue absorption and scattering in vivo","volume":"13","author":"Yu","year":"2008","journal-title":"J. Biomed. Opt."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1703","DOI":"10.1364\/BOE.2.001703","article-title":"Narrow-band pass filter array for integrated opto-electronic spectroscopy detectors to assess esophageal tissue","volume":"2","author":"Ferreira","year":"2011","journal-title":"Biomed. Opt. Express"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"113","DOI":"10.2147\/COPD.S1119","article-title":"Treatment of COPD: A matrix perspective","volume":"3","author":"Dunsmore","year":"2008","journal-title":"Int. J. Chron. Obstruct. Pulmon. Dis."},{"key":"ref_12","unstructured":"Pimenta, S., Castanheira, E.M.S., and Minas, G. (2014, January 7\u20139). Preliminary Monte Carlo based inverse model to extract optical tissue properties from experimental diffuse reflectance measurements\u2014Coefficients extraction for gastrointestinal dysplasia detection. Lisbon, Portugal."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"426","DOI":"10.1364\/AO.32.000426","article-title":"Condensed Monte Carlo simulations for the description of light transport","volume":"32","author":"Graaff","year":"1993","journal-title":"Appl. Opt."},{"key":"ref_14","unstructured":"Wang, L., and Jacques, S.L. Monte Carlo for Multi-Layered Media. Available online: http:\/\/omlc.ogi.edu\/software\/mc."},{"key":"ref_15","unstructured":"M\u00e4tzler, C. Maetzler's MATLAB Code for Mie Theory. Available online: http:\/\/omlc.ogi.edu\/software\/mie\/."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2633","DOI":"10.1109\/TBME.2011.2160263","article-title":"Spectroscopic detection of gastrointestinal dysplasia using optical microsensors","volume":"58","author":"Ferreira","year":"2011","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Valeur, B. (2001). Molecular Fluorescence: Principles and Applications Germany, Wiley-VCH.","DOI":"10.1002\/3527600248"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1451","DOI":"10.1364\/OL.25.001451","article-title":"Turbidity-free fluorescence spectroscopy of biological tissue","volume":"25","author":"Zhang","year":"2000","journal-title":"Opt. Lett."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Lakowicz, J.R. (2006). Principles Fluorescence Spectroscopy, Springer. [3rd ed.].","DOI":"10.1007\/978-0-387-46312-4"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"290","DOI":"10.1016\/j.nima.2008.01.101","article-title":"Wavelength shifters for water cherenkov detectors","volume":"589","author":"Dai","year":"2008","journal-title":"Nucl. Instrum. Meth. Phys. Res. A"},{"key":"ref_21","unstructured":"Meyers, R.A. (2000). Encyclopedia of Analytical Chemistry, John Wiley & Sons Ltd."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"3585","DOI":"10.1364\/AO.32.003585","article-title":"Analytical model for extracting intrinsic fluorescence in turbid media","volume":"32","author":"Wu","year":"1993","journal-title":"Appl. Opt."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"4633","DOI":"10.1364\/AO.40.004633","article-title":"Intrinsic fuorescence spectroscopy in turbid media: Disentangling effects of scattering and absorption","volume":"40","author":"Georgakoudi","year":"2001","journal-title":"Appl. Opt."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/15\/2\/3138\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T20:42:10Z","timestamp":1760215330000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/15\/2\/3138"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,1,30]]},"references-count":23,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2015,2]]}},"alternative-id":["s150203138"],"URL":"https:\/\/doi.org\/10.3390\/s150203138","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2015,1,30]]}}}