{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/30834"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/30834","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Diffuse photon transport in tissue-like media: Resolution limit for near-infrared imaging and an instrument for clinical spectroscopy of tissues","abstract":"In this work I present the model for diffusive photon transport in tissue-like media along with solutions for a point source in infinite and semi-infinite media. Based on these solutions and experimental measurements, I consider the ultimate resolution of near-infrared based imaging of tissues using a simple model to describe resolution. I conclude that for a 5 cm thick tissue, the closest two objects buried in the center can be, and still be resolved is roughly 1.5 centimeters. I also show that light applied to the surface of a tissue-like medium, and detected on the same surface some distance away, penetrates into the medium. The depth of penetration is on the order of centimeters depending on the transport properties of the medium and source-detector separation. Since this light penetrates into tissue, and there is a model which describes how the transport of light through tissues depends on the tissue optical properties with sufficient accuracy, noninvasive tissue spectroscopy in the near-infrared is possible. During my thesis work a functioning tissue spectrometer was developed to demonstrate this point. I conclude by discussing measurements I made with this spectrometer on both laboratory samples and live patients. My experiments with the tissue spectrometer were instrumental in both demonstrating its capabilities and understanding advances to be made in the next generation of the device.","abstract_html":"In this work I present the model for diffusive photon transport in tissue-like media along with solutions for a point source in infinite and semi-infinite media. Based on these solutions and experimental measurements, I consider the ultimate resolution of near-infrared based imaging of tissues using a simple model to describe resolution. I conclude that for a 5 cm thick tissue, the closest two objects buried in the center can be, and still be resolved is roughly 1.5 centimeters. I also show that light applied to the surface of a tissue-like medium, and detected on the same surface some distance away, penetrates into the medium. The depth of penetration is on the order of centimeters depending on the transport properties of the medium and source-detector separation. Since this light penetrates into tissue, and there is a model which describes how the transport of light through tissues depends on the tissue optical properties with sufficient accuracy, noninvasive tissue spectroscopy in the near-infrared is possible. During my thesis work a functioning tissue spectrometer was developed to demonstrate this point. I conclude by discussing measurements I made with this spectrometer on both laboratory samples and live patients. My experiments with the tissue spectrometer were instrumental in both demonstrating its capabilities and understanding advances to be made in the next generation of the device.","abstract_has_math":false,"creators":["Maier, John Stewart"],"institution":null,"degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Gratton, E."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-05-10T20:10:10Z","date_published":"2012-05-10T20:10:10Z","updated_at":"2026-07-22T22:25:29Z","subjects":["photon transport","near-infrared","tissue spectroscopy"],"languages":["en"],"rights":["©1998 John Stewart Maier"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["4163765"],"render_values":[{"text":"4163765","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/30834","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Gratton, E."]},{"key":"dc:creator","label":"Author","values":["Maier, John Stewart"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2012-05-10T20:10:10Z","10000-01-01","1998"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation / Thesis","text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Physics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["photon transport","near-infrared","tissue spectroscopy"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["©1998 John Stewart Maier"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["4163765","http://hdl.handle.net/2142/30834"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["In this work I present the model for diffusive photon transport in tissue-like media along with solutions for a point source in infinite and semi-infinite media. Based on these solutions and experimental measurements, I consider the ultimate resolution of near-infrared based imaging of tissues using a simple model to describe resolution. I conclude that for a 5 cm thick tissue, the closest two objects buried in the center can be, and still be resolved is roughly 1.5 centimeters. I also show that light applied to the surface of a tissue-like medium, and detected on the same surface some distance away, penetrates into the medium. The depth of penetration is on the order of centimeters depending on the transport properties of the medium and source-detector separation. Since this light penetrates into tissue, and there is a model which describes how the transport of light through tissues depends on the tissue optical properties with sufficient accuracy, noninvasive tissue spectroscopy in the near-infrared is possible. During my thesis work a functioning tissue spectrometer was developed to demonstrate this point. I conclude by discussing measurements I made with this spectrometer on both laboratory samples and live patients. My experiments with the tissue spectrometer were instrumental in both demonstrating its capabilities and understanding advances to be made in the next generation of the device.","Submitted by Megan Hayes (mohayes2@illinois.edu) on 2012-05-10T20:10:10Z No. of bitstreams: 1 1998_maier.pdf: 3329520 bytes, checksum: 93495028ab9fe406b99788d2b0bed70b (MD5)","Made available in DSpace on 2012-05-10T20:10:10Z (GMT). No. of bitstreams: 1 1998_maier.pdf: 3329520 bytes, checksum: 93495028ab9fe406b99788d2b0bed70b (MD5) Previous issue date: 1998","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Megan Hayes (mohayes2@illinois.edu) on 2012-05-10T20:10:10Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:33:15-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: thesis","thesis","U of I Only"]},{"key":"dc:title","label":"Title","values":["Diffuse photon transport in tissue-like media: Resolution limit for near-infrared imaging and an instrument for clinical spectroscopy of tissues"]}]}],"canonical_facts":{"dc:contributor":["Gratton, E."],"dc:creator":["Maier, John Stewart"],"dc:date":["2012-05-10T20:10:10Z","10000-01-01","1998"],"dc:description":["In this work I present the model for diffusive photon transport in tissue-like media along with solutions for a point source in infinite and semi-infinite media. Based on these solutions and experimental measurements, I consider the ultimate resolution of near-infrared based imaging of tissues using a simple model to describe resolution. I conclude that for a 5 cm thick tissue, the closest two objects buried in the center can be, and still be resolved is roughly 1.5 centimeters. I also show that light applied to the surface of a tissue-like medium, and detected on the same surface some distance away, penetrates into the medium. The depth of penetration is on the order of centimeters depending on the transport properties of the medium and source-detector separation. Since this light penetrates into tissue, and there is a model which describes how the transport of light through tissues depends on the tissue optical properties with sufficient accuracy, noninvasive tissue spectroscopy in the near-infrared is possible. During my thesis work a functioning tissue spectrometer was developed to demonstrate this point. I conclude by discussing measurements I made with this spectrometer on both laboratory samples and live patients. My experiments with the tissue spectrometer were instrumental in both demonstrating its capabilities and understanding advances to be made in the next generation of the device.","Submitted by Megan Hayes (mohayes2@illinois.edu) on 2012-05-10T20:10:10Z No. of bitstreams: 1 1998_maier.pdf: 3329520 bytes, checksum: 93495028ab9fe406b99788d2b0bed70b (MD5)","Made available in DSpace on 2012-05-10T20:10:10Z (GMT). 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