{"id":{"repo_id":"mit","oai_identifier":"oai:dspace.mit.edu:1721.1/38275"},"canonical_url":"https://search.dev.ndltd.org/etd/mit/oai:dspace.mit.edu:1721.1/38275","repository":{"repo_id":"mit","name":"MIT","base_url":"https://dspace.mit.edu/oai/request"},"display":{"title":"Design and thermal modeling of a non-invasive probe for measuring perfusion by thermodiffusion","abstract":"This research 1) explores the feasibility of developing a non-invasive probe to precisely quantify microcirculatory blood flow (tissue perfusion), in real time and in absolute units, and 2) presents designs and models of such a probe, along with an evaluation of various design-model combinations. Bowman et al. have developed an invasive thermodiffusion probe that measures tissue perfusion accurately, continuously, and in real time. This method employs a self-heated thermistor placed in perfused tissue. From a knowledge of the power required to heat the thermistor probe to a given temperature, perfusion can be calculated using an analytical or numerical model. Using Bowman's thermodiffusion probe (designed for invasive use) in a non-invasive manner, a perfusion study was performed. The data clearly show the promise of a non-invasive thermodiffusion perfusion probe (designed for non-invasive use), and the design of such a probe was pursued by adapting the invasive technology for a non-invasive probe. Because perfusion is not actually measured but calculated from measured quantities by a model of the probe and perfused tissue, the design of the non-invasive probe occurred hand-in-hand with the development of analytical models.","abstract_html":"This research 1) explores the feasibility of developing a non-invasive probe to precisely quantify microcirculatory blood flow (tissue perfusion), in real time and in absolute units, and 2) presents designs and models of such a probe, along with an evaluation of various design-model combinations. Bowman et al. have developed an invasive thermodiffusion probe that measures tissue perfusion accurately, continuously, and in real time. This method employs a self-heated thermistor placed in perfused tissue. From a knowledge of the power required to heat the thermistor probe to a given temperature, perfusion can be calculated using an analytical or numerical model. Using Bowman's thermodiffusion probe (designed for invasive use) in a non-invasive manner, a perfusion study was performed. The data clearly show the promise of a non-invasive thermodiffusion perfusion probe (designed for non-invasive use), and the design of such a probe was pursued by adapting the invasive technology for a non-invasive probe. Because perfusion is not actually measured but calculated from measured quantities by a model of the probe and perfused tissue, the design of the non-invasive probe occurred hand-in-hand with the development of analytical models.","abstract_has_math":false,"creators":["Charles, Steven Knight"],"institution":"Massachusetts Institute of Technology","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Massachusetts Institute of Technology. Dept. of Mechanical Engineering.","school":null,"contributors":[],"advisors":["H. Frederick Bowman."],"committee_chairs":[],"committee_members":[],"year":2004,"date_issued":"2004","date_published":"2004","updated_at":"2026-07-22T22:21:54Z","subjects":["Mechanical Engineering."],"languages":["eng"],"rights":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."],"rights_urls":["http://dspace.mit.edu/handle/1721.1/7582"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1721.1/38275","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["H. Frederick Bowman."]},{"key":"dc:contributor.department","label":"Department","values":["Massachusetts Institute of Technology. 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They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. 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Bowman et al. have developed an invasive thermodiffusion probe that measures tissue perfusion accurately, continuously, and in real time. This method employs a self-heated thermistor placed in perfused tissue. From a knowledge of the power required to heat the thermistor probe to a given temperature, perfusion can be calculated using an analytical or numerical model. Using Bowman's thermodiffusion probe (designed for invasive use) in a non-invasive manner, a perfusion study was performed. The data clearly show the promise of a non-invasive thermodiffusion perfusion probe (designed for non-invasive use), and the design of such a probe was pursued by adapting the invasive technology for a non-invasive probe. Because perfusion is not actually measured but calculated from measured quantities by a model of the probe and perfused tissue, the design of the non-invasive probe occurred hand-in-hand with the development of analytical models.","(cont.) The results of the clinical study are presented, as well as two designs together with possible one-dimensional analytical models. Using a finite-difference model of the two probe designs and the underlying perfused tissue, the errors that result from approximating these designs as one-dimensional models have been determined. It is shown that modeling a thin, disk-shaped thermistor probe as a hemisphere of appropriate radius can result in an error in calculated perfusion which is small enough for clinical use."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["S.M."]},{"key":"dc:title","label":"Title","values":["Design and thermal modeling of a non-invasive probe for measuring perfusion by thermodiffusion"]}]}],"canonical_facts":{"dc:contributor.advisor":["H. Frederick Bowman."],"dc:contributor.department":["Massachusetts Institute of Technology. Dept. of Mechanical Engineering."],"dc:contributor.other":["Massachusetts Institute of Technology. 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From a knowledge of the power required to heat the thermistor probe to a given temperature, perfusion can be calculated using an analytical or numerical model. Using Bowman's thermodiffusion probe (designed for invasive use) in a non-invasive manner, a perfusion study was performed. The data clearly show the promise of a non-invasive thermodiffusion perfusion probe (designed for non-invasive use), and the design of such a probe was pursued by adapting the invasive technology for a non-invasive probe. Because perfusion is not actually measured but calculated from measured quantities by a model of the probe and perfused tissue, the design of the non-invasive probe occurred hand-in-hand with the development of analytical models.","(cont.) The results of the clinical study are presented, as well as two designs together with possible one-dimensional analytical models. Using a finite-difference model of the two probe designs and the underlying perfused tissue, the errors that result from approximating these designs as one-dimensional models have been determined. It is shown that modeling a thin, disk-shaped thermistor probe as a hemisphere of appropriate radius can result in an error in calculated perfusion which is small enough for clinical use."],"dc:description.degree":["S.M."],"dc:identifier.uri":["http://hdl.handle.net/1721.1/38275"],"dc:language.iso":["eng"],"dc:publisher":["Massachusetts Institute of Technology"],"dc:rights":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."],"dc:rights.uri":["http://dspace.mit.edu/handle/1721.1/7582"],"dc:subject":["Mechanical Engineering."],"dc:title":["Design and thermal modeling of a non-invasive probe for measuring perfusion by thermodiffusion"],"dc:type":["Thesis"]},"updated_at":"2026-07-22T22:21:54Z"}