{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,24]],"date-time":"2026-04-24T10:36:37Z","timestamp":1777026997865,"version":"3.51.4"},"reference-count":55,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2021,1,5]],"date-time":"2021-01-05T00:00:00Z","timestamp":1609804800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"The Slovenian Research Agency (ARRS)","award":["P1-0389"],"award-info":[{"award-number":["P1-0389"]}]},{"name":"The Slovenian Research Agency (ARRS)","award":["P1-0192"],"award-info":[{"award-number":["P1-0192"]}]},{"name":"The Slovenian Research Agency (ARRS)","award":["PR-07590"],"award-info":[{"award-number":["PR-07590"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>We have augmented a recently introduced method for noninvasive analysis of skin structure and composition and applied it to monitoring of dynamical processes in traumatic bruises. The approach combines diffuse reflectance spectroscopy in visible spectral range and pulsed photothermal radiometry. Data from both techniques are analyzed simultaneously using a numerical model of light and heat transport in a four-layer model of human skin. Compared to the earlier presented approach, the newly introduced elements include two additional chromophores (\u03b2-carotene and bilirubin), individually adjusted thickness of the papillary dermal layer, and analysis of the bruised site using baseline values assessed from intact skin in its vicinity. Analyses of traumatic bruises in three volunteers over a period of 16 days clearly indicate a gradual, yet substantial increase of the dermal blood content and reduction of its oxygenation level in the first days after injury. This is followed by the emergence of bilirubin and relaxation of all model parameters towards the values characteristic for healthy skin approximately two weeks after the injury. The assessed parameter values and time dependences are consistent with existing literature. Thus, the presented methodology offers a viable approach for objective characterization of the bruise healing process.<\/jats:p>","DOI":"10.3390\/s21010302","type":"journal-article","created":{"date-parts":[[2021,1,5]],"date-time":"2021-01-05T10:35:12Z","timestamp":1609842912000},"page":"302","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Noninvasive Monitoring of Dynamical Processes in Bruised Human Skin Using Diffuse Reflectance Spectroscopy and Pulsed Photothermal Radiometry"],"prefix":"10.3390","volume":"21","author":[{"given":"Ana","family":"Marin","sequence":"first","affiliation":[{"name":"Faculty of Mathematics and Physics, University of Ljubljana, 1000 Ljubljana, Slovenia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4951-3638","authenticated-orcid":false,"given":"Nina","family":"Verdel","sequence":"additional","affiliation":[{"name":"Department of Complex Matter, Jo\u017eef Stefan Institute, 1000 Ljubljana, Slovenia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4417-0293","authenticated-orcid":false,"given":"Matija","family":"Milani\u010d","sequence":"additional","affiliation":[{"name":"Faculty of Mathematics and Physics, University of Ljubljana, 1000 Ljubljana, Slovenia"},{"name":"Department of Complex Matter, Jo\u017eef Stefan Institute, 1000 Ljubljana, Slovenia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2841-8276","authenticated-orcid":false,"given":"Boris","family":"Majaron","sequence":"additional","affiliation":[{"name":"Faculty of Mathematics and Physics, University of Ljubljana, 1000 Ljubljana, Slovenia"},{"name":"Department of Complex Matter, Jo\u017eef Stefan Institute, 1000 Ljubljana, Slovenia"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1016\/0379-0738(91)90154-B","article-title":"The Ageing of Bruises: A Review and Study of the Colour Changes with Time","volume":"50","author":"Langlois","year":"1991","journal-title":"Forensic Sci. Int."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1136\/adc.74.1.53","article-title":"Estimation of the Age of Bruising","volume":"74","author":"Stephenson","year":"1996","journal-title":"Arch. Dis. Child."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"170","DOI":"10.1258\/msl.2011.010135","article-title":"Can We Assess the Age of Bruises? An Attempt to Develop an Objective Technique","volume":"51","author":"Grossman","year":"2011","journal-title":"Med. Sci. Law"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"367","DOI":"10.1007\/s12024-013-9452-4","article-title":"Evaluating Change in Bruise Colorimetry and The Effect of Subject Characteristics Over Time","volume":"9","author":"Scafide","year":"2013","journal-title":"Forensic Sci. Med. Pathol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"109831","DOI":"10.1016\/j.forsciint.2019.05.047","article-title":"Determination of the Age of Bruises Using a Bilirubinometer","volume":"302","author":"Mesli","year":"2019","journal-title":"Forensic Sci. Int."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1136\/jcp.2003.011445","article-title":"The Practical Application of Reflectance Spectrophotometry for the Demonstration of Haemoglobin and its Degradation in Bruises","volume":"57","author":"Hughes","year":"2004","journal-title":"J. Clin. Pathol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1002\/lsm.20301","article-title":"A Novel Approach to Age Determination of Traumatic Injuries by Reflectance Spectroscopy","volume":"38","author":"Randeberg","year":"2006","journal-title":"Lasers Surg. Med."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1088\/0967-3334\/33\/2\/159","article-title":"Reflectance spectrometry of Normal and Bruised Human Skins: Experiments and modeling","volume":"33","author":"Kim","year":"2012","journal-title":"Physiol. Meas."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"109998","DOI":"10.1016\/j.forsciint.2019.109998","article-title":"On the Relationships between Applied Force, Photography Technique, and the Quantification of Bruise Appearance","volume":"305","author":"Black","year":"2019","journal-title":"Forensic Sci. Int."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Tirado, J., and Mauricio, D. (2020). Bruise Dating Using Deep Learning. J. Forensic Sci.","DOI":"10.1111\/1556-4029.14578"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1002\/jbio.200910059","article-title":"Characterization of Vascular Structures and Skin Bruises Using Hyperspectral Imaging, Image Analysis and Diffusion Theory","volume":"3","author":"Randeberg","year":"2009","journal-title":"J. Biophotonics"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"759","DOI":"10.1002\/jbio.201100021","article-title":"Can Color Inhomogeneity of bruises be Used to Establish Their Age?","volume":"4","author":"Stam","year":"2011","journal-title":"J. Biophotonics"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1002\/jbio.201300198","article-title":"Chromophore Based Analyses of Steady-State Diffuse Reflectance Spectroscopy: Current Status and Perspectives for Clinical Adoption","volume":"8","author":"Bydlon","year":"2014","journal-title":"J. Biophotonics"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Vidovi\u010d, L., Milani\u010d, M., Randeberg, L.L., and Majaron, B. (2015, January 26). Quantitative Characterization of Traumatic Bruises by Combined Pulsed Photothermal Radiometry and Diffuse Reflectance Spectroscopy. Proceedings of the Photonic Therapeutics and Diagnostics XI, SPIE-Intl Soc Optical Eng, San Francisco, CA, USA.","DOI":"10.1117\/12.2077188"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"905","DOI":"10.1364\/OSAC.2.000905","article-title":"Suitability of Diffusion Approximation for an Inverse Analysis of Diffuse Reflectance Spectra from Human Skin In Vivo","volume":"2","author":"Randeberg","year":"2019","journal-title":"OSA Contin."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2829","DOI":"10.1088\/0031-9155\/54\/9\/016","article-title":"A Spectrally composite Reconstruction Approach for Improved Resolution of Pulsed Photothermal Temperature Profiling in Water-Based Samples","volume":"54","author":"Majaron","year":"2009","journal-title":"Phys. Med. Biol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"961","DOI":"10.1117\/1.1784470","article-title":"Accurate Measurement of Blood Vessel Depth in Port wine Stained Human Skin In Vivo Using Pulsed Photothermal Radiometry","volume":"9","author":"Li","year":"2004","journal-title":"J. Biomed. Opt."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"017001","DOI":"10.1117\/1.JBO.20.1.017001","article-title":"Objective Characterization of Bruise Evolution Using Photothermal Depth Profiling and Monte Carlo Modeling","volume":"20","author":"Majaron","year":"2015","journal-title":"J. Biomed. Opt."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"944","DOI":"10.1364\/BOE.10.000944","article-title":"Physiological and Structural Characterization of Human Skin In Vivo Using Combined Photothermal Radiometry and Diffuse Reflectance Spectroscopy","volume":"10","author":"Verdel","year":"2019","journal-title":"Biomed. Opt. Express"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"D117","DOI":"10.1364\/AO.57.00D117","article-title":"Noninvasive Assessment of Skin Structure by Combined Photothermal Radiometry and Optical Spectroscopy: Coregistration with Multiphoton Microscopy","volume":"57","author":"Verdel","year":"2018","journal-title":"Appl. Opt."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Verdel, N., and Majaron, B. (2020, January 24\u201325). Objective Noninvasive Monitoring of Laser Tattoo Removal in a Human Volunteer: A Proof of Principle Study. Proceedings of the Third International Conference Biophotonics Riga 2020, Riga, Latvia.","DOI":"10.1117\/12.2582137"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Marin, A., Milani\u010d, M., Verdel, N., Vidovi\u010d, L., and Majaron, B. (February, January 27). Dynamics of Controllably Induced Bruises Assessed by Diffuse Reflectance Spectroscopy and Pulsed Photothermal Radiometry. Proceedings of the SPIE BiOS, 2018, San Francisco CA, USA.","DOI":"10.1117\/12.2289982"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Marin, A., Verdel, N., Milani\u010d, M., and Majaron, B. (2019, January 21\u201325). Influence of Healthy Skin Baseline on Bruise Dynamics Parameters as Assessed by Optical methods. Proceedings of the European Conferences on Biomedical Optics, Munich, Germany.","DOI":"10.1117\/12.2527083"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1111\/j.1600-0846.2005.00094.x","article-title":"Estimation of the Relative Stratum Corneum Amount Removed by Tape Stripping","volume":"11","author":"Jacobi","year":"2005","journal-title":"Ski. Res. Technol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"27006","DOI":"10.1117\/1.JBO.19.2.027006","article-title":"Elimination of Single-Beam Substitution Error in Diffuse Reflectance Measurements Using an Integrating Sphere","volume":"19","author":"Majaron","year":"2014","journal-title":"J. Biomed. Opt."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"774","DOI":"10.1002\/lsm.23108","article-title":"Temperature Depth Profiles Induced in Human Skin In Vivo Using Pulsed 975 nm Irradiation","volume":"51","author":"Cenian","year":"2019","journal-title":"Lasers Surg. Med."},{"key":"ref_27","unstructured":"ALIA (2020, December 18). ANSI Z136 Standards. Available online: https:\/\/www.lia.org\/resources\/laser-safety-information\/laser-safety-standards\/ansi-z136-standards."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"R37","DOI":"10.1088\/0031-9155\/58\/11\/R37","article-title":"Optical Properties of Biological Tissues: A review","volume":"58","author":"Jacques","year":"2013","journal-title":"Phys. Med. Biol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1742","DOI":"10.1364\/AO.46.001742","article-title":"Empirical Model Functions to Calculate Hematocrit-Dependent Optical Properties of Human Blood","volume":"46","author":"Meinke","year":"2007","journal-title":"Appl. Opt."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1016\/j.abb.2018.03.033","article-title":"Optical Assessment of Skin Carotenoid Status as a Biomarker of Vegetable and Fruit Intake","volume":"646","author":"Ermakov","year":"2018","journal-title":"Arch. Biochem. Biophys."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2465","DOI":"10.1088\/0031-9155\/43\/9\/003","article-title":"Near-Infrared Optical Properties of In Vivo Human Skin and Subcutaneous Tissues Measured Using the Monte Carlo Inversion Technique","volume":"43","author":"Simpsonyz","year":"1998","journal-title":"Phys. Med. Biol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2543","DOI":"10.1088\/0022-3727\/38\/15\/004","article-title":"Optical Properties of Human Skin, Subcutaneous and Mucous Tissues in the Wavelength Range from 400 to 2000 nm","volume":"38","author":"Bashkatov","year":"2005","journal-title":"J. Phys. D: Appl. Phys."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1007\/s12024-007-9019-3","article-title":"The Science Behind the Quest to Determine the Age of Bruises\u2014A Review of the English Language Literature","volume":"3","author":"Langlois","year":"2007","journal-title":"Forensic Sci. Med. Pathol."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Marin, A., Verdel, N., and Majaron, B. (2020, January 1\u20132). Hemodynamics in Traumatic Bruises Assessed by Diffuse Reflectance Spectroscopy and Photothermal Radiometry. Proceedings of the SPIE BiOS, San Francisco, CA, USA.","DOI":"10.1117\/12.2545876"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1016\/0169-2607(95)01640-F","article-title":"MCML\u2014Monte Carlo Modeling of Light Transport in Multi-Layered Tissues","volume":"47","author":"Wang","year":"1995","journal-title":"Comput. Methods Programs Biomed."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"658","DOI":"10.1364\/BOE.1.000658","article-title":"Next-Generation Acceleration and Code Optimization for Light Transport in Turbid Media Using GPUs","volume":"1","author":"Alerstam","year":"2010","journal-title":"Biomed. Opt. Express"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"263","DOI":"10.1111\/srt.12256","article-title":"Skin Characteristics: Normative Data for Elasticity, Erythema, Melanin, and Thickness at 16 Different Anatomical Locations","volume":"22","author":"Nedelec","year":"2015","journal-title":"Ski. Res. Technol."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"McMurdy, J.W., Duffy, S., and Crawford, G.P. (2007, January 20\u201325). Monitoring Bruise Age Using Visible Diffuse Reflectance Spectroscopy. Proceedings of the SPIE BiOS, San Jose, CA, USA.","DOI":"10.1117\/12.701592"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1016\/j.forsciint.2003.09.022","article-title":"Spectrophotometric and Tristimulus Analysis of the Colors of Subcutaneous Bleeding in Living Persons","volume":"156","author":"Yajima","year":"2006","journal-title":"Forensic Sci. Int."},{"key":"ref_40","first-page":"160","article-title":"Anatomy and Biochemistry of Skin","volume":"Volume I","author":"Kydonieus","year":"1987","journal-title":"Transdermal Delivery of Drugs"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1099","DOI":"10.1007\/s11095-012-0946-7","article-title":"Transdermal Delivery of Molecules is Limited by Full Epidermis, Not Just Stratum Corneum","volume":"30","author":"Andrews","year":"2013","journal-title":"Pharm. Res."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1042\/bj1360035","article-title":"Uptake and Release of Bilirubin by Skin","volume":"136","author":"Kapoor","year":"1973","journal-title":"Biochem. J."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"69152","DOI":"10.1117\/12.770399","article-title":"Bruise Chromophore Concentrations Over Time","volume":"6915","author":"Duckworth","year":"2008","journal-title":"Med. Imaging"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"0770051","DOI":"10.1117\/1.JBO.17.7.077005","article-title":"Noninvasive Evaluation of Collagen and Hemoglobin Contents and Scattering Property of In Vivo Keloid Scars and Normal Skin Using Diffuse Reflectance Spectroscopy: Pilot study","volume":"17","author":"Tseng","year":"2012","journal-title":"J. Biomed. Opt."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1080\/23328940.2015.1088502","article-title":"Arterio-venous Anastomoses in the Human Skin and Their Role in Temperature Control","volume":"3","year":"2016","journal-title":"Temperature"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1155\/2013\/703571","article-title":"Natural History of the Bruise: Formation, Elimination, and Biological Effects of Oxidized Hemoglobin","volume":"2013","author":"Jeney","year":"2013","journal-title":"Oxidative Med. Cell. Longev."},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Randeberg, L.L., Skallerud, B.H., Langlois, N.E., Haugen, O.A., Svaasand, L.O., and Gemert, M.J. (2010). The Optics of Bruising. Optical-Thermal Response of Laser-Irradiated Tissue, Springer Science and Business Media LLC.","DOI":"10.1007\/978-90-481-8831-4_22"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1016\/j.chiabu.2018.03.017","article-title":"A Pilot Study Demonstrating the Efficacy of Transcutaneous Bilirubin Meters to Quantitatively Differentiate Contusions from Congenital Dermal Melanocytosis","volume":"80","author":"Abdy","year":"2018","journal-title":"Child Abus. Negl."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1117\/1.429919","article-title":"Optical Properties of Circulating Human Blood in the Wavelength Range 400\u20132500 nm","volume":"4","author":"Roggan","year":"1999","journal-title":"J. Biomed. Opt."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"332","DOI":"10.1007\/s10043-015-0177-3","article-title":"Evaluation of Light Scattering Properties and Chromophore Concentrations in Skin Tissue Based on Diffuse Reflectance Signals at Isosbestic Wavelengths of Hemoglobin","volume":"23","author":"Yokokawa","year":"2016","journal-title":"Opt. Rev."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"091416","DOI":"10.1117\/1.JBO.23.9.091416","article-title":"Measurement of Tissue Optical Properties in the Context of Tissue Optical Clearing","volume":"23","author":"Bashkatov","year":"2018","journal-title":"J. Biomed. Opt."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"404","DOI":"10.1016\/j.ijbiomac.2013.08.001","article-title":"Studies on the Molecular Significance in the Interaction of Bilirubin with Collagen","volume":"61","author":"Nagarajan","year":"2013","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"266","DOI":"10.23907\/2015.029","article-title":"Histological Aging of Bruising: A Historical and Ongoing Challenge","volume":"5","author":"Parai","year":"2015","journal-title":"Acad. Forensic Pathol."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"3545","DOI":"10.1364\/BOE.10.003545","article-title":"Hyperspectral Imaging of Human Skin Aided by Artificial Neural Networks","volume":"10","author":"Zherebtsov","year":"2019","journal-title":"Biomed. Opt. Express"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1679","DOI":"10.1364\/BOE.384982","article-title":"Predictive Model for the Quantitative Analysis of Human Skin Using Photothermal Radiometry and Diffuse Reflectance Spectroscopy","volume":"11","author":"Verdel","year":"2020","journal-title":"Biomed. Opt. Express"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/1\/302\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:07:01Z","timestamp":1760159221000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/1\/302"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,1,5]]},"references-count":55,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2021,1]]}},"alternative-id":["s21010302"],"URL":"https:\/\/doi.org\/10.3390\/s21010302","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,1,5]]}}}