Ethan Murphy

Overview

My research primarily involves physics-based electrical modeling, imaging electrical properties with a technique called electrical impedance tomography (EIT), and using a combination of computational techniques to improve these methods for practical biomedical applications. Much of my work involves 3D mesh generation for finite element method problems and fusing data from multiple data sources.

Research Interests

Electrical impedance tomography; data fusion; finite element method (FEM) modeling; noise/data filtering; general numerical methods; magnetic resonance electrical property tomography; electroencephalogram (EEG) source localization

Education

• BS, Mathematics, Worcester Polytechnic Institute 2002
• MS, Industrial Mathematics, Worcester Polytechnic Institute 2002
• PhD, Mathematics, Colorado State University 2007

Awards

• Society of Critical Care Medicine's Gold Snapshot Award, 2021
• Clinical Poster Award, Northeast Amyotrophic Lateral Sclerosis Conference, 2019
• Best Creative Work, Saratov State Technical University, 2010

Research Projects

• Using Electrical impedance for bleed detection

  Using Electrical impedance for bleed detection

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• Computational modeling and optimization of transcranial direct current stimulation (tDCS) for pain applications

  Computational modeling and optimization of transcranial direct current stimulation (tDCS) for pain applications

  Studies transcranial TemporalInterference Stimulation (tTIS), a groundbreaking new method that enables non-invasive modulation of deep brain regions. tTIS applies high-frequency alternating currents to multiple scalp locations simultaneously, creating a stimulation envelope at a targeted frequency and brain location. This represents a paradigm shift in neuromodulation technology.

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• Electrical impedance imaging of cancer

  Electrical impedance imaging of cancer

  Electrical impedance imaging of cancer is the process of imaging the electrical property (conductivity and permittivity) of tissue using electrodes. This project is one branch of the larger effort to develop innovative technologies for cancer detection.

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• Electrical impedance tomography in pulmonary and cardiac applications

  Electrical impedance tomography in pulmonary and cardiac applications

  The most common application, so far, of electrical impedance tomography (EIT) has been pulmonary monitoring of patients. In particular, we have been pursuing EIT for cardiac output monitoring (a related application) and EIT as a surrogate for pulmonary function tests.

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• Combined whole breast ultrasound and electrical impedance tomography

  Combined whole breast ultrasound and electrical impedance tomography

  Ultrasound is a supplemental screening technique that has good sensitivity in dense breasts, is inexpensive, and is widely available, but unfortunately, it has high rates of false positives. Electrical impedance tomography (EIT) is a second attractive modality that is low-cost and has shown promise for cancer detection and in differentiating fibrocystic tissues from other tissues. Combining automated whole breast ultrasound (ABUS), which is a recent improvement to standard ultrasound, with EIT may significantly reduce the number of false positives of ABUS. If successful, the combined ABUS/EIT system could become an important screening technology for women with dense breasts.

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• Imaging muscle properties with combined ultrasound and electrical impedance tomography

  Imaging muscle properties with combined ultrasound and electrical impedance tomography

  Assessing muscle health is important diagnostic information in the treatment of numerous peripheral nerve diseases. This project aims to incorporate spatial information from ultrasound into the inverse problem of electrical impedance tomography in order to accurately image the electrical properties of the muscle (under the skin and adipose tissue).

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Selected Publications

• E.K. Murphy, D. Bustamante, H. Raeis, R.J. Halter, and M. Mehrmohammadi, 2026. Combined ultrasound tomography and electrical impedance tomography: feasibility studies on breast-mimicking phantoms. Proceedings of SPIE Medical Imaging, Vancouver, BC, Canada. doi: 10.1117/12.3091944.
• E.K. Murphy, X. Wu, A. Everitt, L.M. Dagrosa, J.R. Pettus, and R.J. Halter, 2025. Ex-vivo Prostate Evaluation of Fused-data TREIT using only Biopsy-probe electrodes. IEEE Transactions on Biomedical Engineering. doi: 10.1109/TBME.2025.11261849.
• E.K. Murphy, S.R. Bertsch, S.B. Klein, N. Rashedi, Y. Sun, M.J. Joyner, T.B. Curry, C.P. Johnson, R.J. Regimbal, C.C. Wiggins, and J.W. Senefeld, 2024. Non-invasive biomarkers for detecting progression toward hypovolemic cardiovascular instability in a lower body negative pressure model. Scientific Reports, 14(1), p.8719. doi: 10.1038/s41598-024-59139-8.
• A. Everitt, H. Richards, Y. Song, J. Smith, E. Kobylarz, T. Lukovits, R. Halter, and E. Murphy, 2023. EEG electrode localization with 3D iPhone scanning using point-cloud electrode selection (PC-ES). Journal of Neural Engineering, 20(6), p.066033. doi: 10.1088/1741-2552/ad12db.
• E.K. Murphy, J. Smith, M.A. Kokko, S.B. Rutkove, and R.J. Halter, 2024. Rapid patient-specific FEM meshes from 3D smart-phone based scans. Physiological Measurement, 45(2), p.025008. doi: 10.1088/1361-6579/ad26d2.
• E.K. Murphy, X. Wu, A. Everitt, and R.J. Halter, "Phantom Studies of Fused-data TREIT using only Biopsy-probe electrodes," IEEE Trans. Med. Imag., 2020 (accepted).
• E.K. Murphy, J. Skinner, M. Martucci, S.B. Rutkove, and R.J. Halter, "Toward Electrical Impedance Tomography Coupled Ultrasound Imaging for Assessing Muscle Health," IEEE Transactions on Medical Imaging, vol. 38, no. 6, pp.1409–1419, 2018.
• E.K. Murphy, X. Wu, and R.J. Halter, "Fused-data Transrectal EIT for Prostate Cancer Imaging," Physiological Measurement, vol. 39, no. 5, p.054005, 2018.
• E.K. Murphy, A. Mahara, X. Wu, and R.J. Halter, "Phantom Experiments using Soft-Prior Regularization EIT for Breast Cancer Imaging," Physiological Measurement, vol. 38, no. 6, pp.1262–1277, 2017.
• E.K. Murphy, A. Mahara, S. Khan, E.S. Hyams, A.R. Schned, J. Pettus, and R.J. Halter, "Comparative Study of Separation between ex vivo Prostatic Malignant and Benign Tissue using Electrical Impedance Spectroscopy and Electrical Impedance Tomography," Physiological Measurement, vol. 38, no. 6, pp.1242–1261, 2017.
• E.K. Murphy, A. Mahara, and R.J. Halter, "Absolute Reconstructions using Rotational Electrical Impedance Tomography for Breast Cancer Imaging," IEEE Trans. on Med. Img., vol. 36, no. 4, pp.892–903, 2017.
• E.K. Murphy, A. Mahara, and R.J. Halter, "A Novel Regularization Technique for Microendoscopic Electrical Impedance Tomography," IEEE Trans. Med. Imaging, vol. 35, no. 7, pp. 1593–1603, 2016.
• V. Brovko, E.K. Murphy, and V.V. Yakovlev, "Waveguide Microwave Imaging: Solids Volume Fraction of Particulate Materials," Appl. Comput. Electromagn. Soc. J., vol. 30, no. 11, pp. 1161–1167, 2015.

News

Welcome: New Faculty
Mar 15, 2021

Joint Dartmouth-Hitchcock and Dartmouth Team Wins Society of Critical Care Medicine Award
Dec 16, 2020

Dartmouth Awarded NIH Grant for Device to Detect Cancer Left Behind During Surgery
Aug 25, 2020

Research Quick Takes

Mar 19, 2026

Early Detection of Hidden Internal Bleeding

Professors Ryan Halter, Jonathan Elliott, Vikrant Vaze, and Ethan Murphy—with Geisel Professor Norman Paradis—were issued a US patent for "System and…

Professors Ryan Halter, Jonathan Elliott, Vikrant Vaze, and Ethan Murphy—with Geisel Professor Norman Paradis—were issued a US patent for "System and method to detect the presence and progression of diseases characterized by systemic changes in the state of the vasculature." The invention uses a novel technique to obtain multiple tissue measurements which are then "transformed by a multivariate algorithm to outputs that convey the diagnostic and prognostic risk of the disease of interest," according to the patent. "We show that by effectively combining signals from multiple sensors using advanced machine learning algorithms, we can save lives through early detection of hidden internal bleeding," said Vaze.

Jul 24, 2025

Novel Complex Impedance Imaging Methods

PhD students Allaire Doussan and Sophie Lloyd, and Professors Ethan Murphy and Ryan Halter are coauthors of "Comparison of Complex Open Domain…

PhD students Allaire Doussan and Sophie Lloyd, and Professors Ethan Murphy and Ryan Halter are coauthors of "Comparison of Complex Open Domain Electrical Impedance Tomography (EIT) Methods" published in IEEE Transactions on Biomedical Engineering. The paper focuses on complex EIT methods and introduces a novel method for handling inversions in permittivity reconstructions.

Feb 27, 2025

Early Detection of Internal Bleeding

PhD student Navid Rashedi (pictured), Professor Ethan Murphy, Alexandra Hamlin '16 Th'17 Th'19, research associate Victor Borza, and Professors…

PhD student Navid Rashedi (pictured), Professor Ethan Murphy, Alexandra Hamlin '16 Th'17 Th'19, research associate Victor Borza, and Professors Jonathan Elliott, Ryan Halter, and Vikrant Vaze are co-authors of: "Detection of occult hemorrhage using multivariate non-invasive technologies" published in Physiological Measurement. "This work investigated machine learning to combine multiple technologies—electrical impedance and near infrared spectroscopy—to better detect internal bleeds in a porcine study. Internal bleeds are often not detectable until it's too late. This approach appears to detect them earlier and more accurately," said Murphy. 

May 02, 2024

EIT for Early Bleed Detection

PhD students Spencer Bertsch Th'19 and Navid Rashedi, alum Yifei Sun Th'22, and Professors Ethan Murphy (first author), Jonathan Elliott, Ryan…

PhD students Spencer Bertsch Th'19 and Navid Rashedi, alum Yifei Sun Th'22, and Professors Ethan Murphy (first author), Jonathan Elliott, Ryan Halter, and Vikrant Vaze—along with DHMC and Mayo Clinic researchers—co-authored "Non-invasive biomarkers for detecting progression toward hypovolemic cardiovascular instability in a lower body negative pressure model" published in Scientific Reports. The paper summarizes how electrical impedance tomography (EIT) can be used as a novel marker for early bleed detection.

Jan 11, 2024

A Better, Safer Surgical Stapler

Professors Ethan Murphy and Ryan Halter, and PhD student Harsha Devaraj, along with Medtronic collaborators, coauthored "Development of an Electrical…

Professors Ethan Murphy and Ryan Halter, and PhD student Harsha Devaraj, along with Medtronic collaborators, coauthored "Development of an Electrical Impedance Tomography Coupled Surgical Stapler for Tissue Characterization" published in IEEE Transactions on Biomedical Engineering. The featured article investigates the incorporation of electrical impedance tomography into a surgical stapler to improve outcomes. Further studies are planned based on the promising results.

Dec 14, 2023

3D iPhone Scanning for EEG

Alums Alicia Everitt Th'19 and Haley Richards Th'22 are first authors on "EEG electrode localization with 3D iPhone scanning using point-cloud…

Alums Alicia Everitt Th'19 and Haley Richards Th'22 are first authors on "EEG electrode localization with 3D iPhone scanning using point-cloud electrode selection" accepted for publication by the Journal of Neural Engineering. The authors, including Professors Ryan Halter and Ethan Murphy, present a method "using an iPhone to produce accurate high-density EEG scans for electrode localization—providing a needed portable and inexpensive solution," says Murphy.