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Full-Text Articles in Biomedical Engineering and Bioengineering

Noncontact Diffuse Correlation Tomography Of Human Breast Tumor, Lian He, Yu Lin, Chong Huang, Daniel Irwin, Margaret M. Szabunio, Guoqiang Yu Aug 2015

Noncontact Diffuse Correlation Tomography Of Human Breast Tumor, Lian He, Yu Lin, Chong Huang, Daniel Irwin, Margaret M. Szabunio, Guoqiang Yu

Biomedical Engineering Faculty Publications

Our first step to adapt our recently developed noncontact diffuse correlation tomography (ncDCT) system for three-dimensional (3-D) imaging of blood flow distribution in human breast tumors is reported. A commercial 3-D camera was used to obtain breast surface geometry, which was then converted to a solid volume mesh. An ncDCT probe scanned over a region of interest on the mesh surface and the measured boundary data were combined with a finite element framework for 3-D image reconstruction of blood flow distribution. This technique was tested in computer simulations and in vivo human breasts with low-grade carcinoma. Results from computer simulations ...


3d Thoracoscopic Ultrasound Volume Measurement Validation In An Ex Vivo And In Vivo Porcine Model Of Lung Tumours, V. Hornblower, E. Yu, A. Fenster, J. Battista, R. Malthaner Jul 2015

3d Thoracoscopic Ultrasound Volume Measurement Validation In An Ex Vivo And In Vivo Porcine Model Of Lung Tumours, V. Hornblower, E. Yu, A. Fenster, J. Battista, R. Malthaner

Richard A. Malthaner

The purpose of this study was to validate the accuracy and reliability of volume measurements obtained using three-dimensional (3D) thoracoscopic ultrasound (US) imaging. Artificial "tumours" were created by injecting a liquid agar mixture into spherical moulds of known volume. Once solidified, the "tumours" were implanted into the lung tissue in both a porcine lung sample ex vivo and a surgical porcine model in vivo. 3D US images were created by mechanically rotating the thoracoscopic ultrasound probe about its long axis while the transducer was maintained in close contact with the tissue. Volume measurements were made by one observer using the ...


3d Thoracoscopic Ultrasound Volume Measurement Validation In An Ex Vivo And In Vivo Porcine Model Of Lung Tumours, V. Hornblower, E. Yu, A. Fenster, J. Battista, R. Malthaner Jul 2015

3d Thoracoscopic Ultrasound Volume Measurement Validation In An Ex Vivo And In Vivo Porcine Model Of Lung Tumours, V. Hornblower, E. Yu, A. Fenster, J. Battista, R. Malthaner

Richard A. Malthaner

The purpose of this study was to validate the accuracy and reliability of volume measurements obtained using three-dimensional (3D) thoracoscopic ultrasound (US) imaging. Artificial "tumours" were created by injecting a liquid agar mixture into spherical moulds of known volume. Once solidified, the "tumours" were implanted into the lung tissue in both a porcine lung sample ex vivo and a surgical porcine model in vivo. 3D US images were created by mechanically rotating the thoracoscopic ultrasound probe about its long axis while the transducer was maintained in close contact with the tissue. Volume measurements were made by one observer using the ...


Effects Of Individualized Centrifugation Training On Orthostatic Tolerance In Men And Women, Nandu Goswami, Joyce Evans, Stefan Schneider, Melanie Von Der Wiesche, Edwin Mulder, Andreas Rössler, Helmut Hinghofer-Szalkay, Andrew P. Blaber May 2015

Effects Of Individualized Centrifugation Training On Orthostatic Tolerance In Men And Women, Nandu Goswami, Joyce Evans, Stefan Schneider, Melanie Von Der Wiesche, Edwin Mulder, Andreas Rössler, Helmut Hinghofer-Szalkay, Andrew P. Blaber

Biomedical Engineering Faculty Publications

AIMS: Exposure to artificial gravity (AG) at different G loads and durations on human centrifuges has been shown to improve orthostatic tolerance in men. However, the effects on women and of an individual-specific AG training protocol on tolerance are not known.

METHODS: We examined the effects of 90 minutes of AG vs. 90 minutes of supine rest on the orthostatic tolerance limit (OTL), using head up tilt and lower body negative pressure until presyncope of 7 men and 5 women. Subjects were placed in the centrifuge nacelle while instrumented and after one-hour they underwent either: 1) AG exposure (90 minutes ...


A Pneumatically Actuated Manipulandum For Neuromotor Control Research, Aaron J Suminski, Kristina Ropella, Robert Scheidt Mar 2015

A Pneumatically Actuated Manipulandum For Neuromotor Control Research, Aaron J Suminski, Kristina Ropella, Robert Scheidt

Robert Scheidt

Functional magnetic resonance imaging (fMRI) techniques have great potential for identifying which neural structures are involved in the control of goal-directed reaching movements. However, fMRI techniques alone are not capable of probing the neural mechanisms involved in acquisition of novel motor behaviors because such studies require that the moving limb be perturbed in a controlled fashion. We outline a plan to design and develop a non-metallic, pneumatically actuated tool that, along with systems identification techniques and functional magnetic resonance imaging (fMRI), will characterize and quantify how the human central nervous system uses sensory information during practice-based motor learning.


Visual Error Augmentation For Enhancing Motor Learning And Rehabilitative Relearning, Yejun Wei, Preeti Bajaj, Robert A. Scheidt, James L. Patton Mar 2015

Visual Error Augmentation For Enhancing Motor Learning And Rehabilitative Relearning, Yejun Wei, Preeti Bajaj, Robert A. Scheidt, James L. Patton

Robert Scheidt

We developed a real-time controller for a 2 degree-of-freedom robotic system using xPC Target. This system was used to investigate how different methods of performance error feedback can lead to faster and more complete motor learning in individuals asked to compensate for a novel visuo-motor transformation (a 30 degree rotation). Four groups of normal human subjects were asked to reach with their unseen arm to visual targets surrounding a central starting location. A cursor tracking hand motion was provided during each reach. For one group of subjects, deviations from the "ideal" compensatory hand movement (i.e. trajectory errors) were amplified ...


A Low-Field P-31 Nmr Spectrometer To Measure Bone Mineral In The Human Wrist, Joseph Battocletti, Thomas Meyers, Robert Scheidt Mar 2015

A Low-Field P-31 Nmr Spectrometer To Measure Bone Mineral In The Human Wrist, Joseph Battocletti, Thomas Meyers, Robert Scheidt

Robert Scheidt

Nuclear magnetic resonance phosphorus spectroscopy (NMRS) is a method of measuring the mineral content of bone as a diagnostic tool for osteoporosis. A description is given of the design and construction of a low-field spectrometer for the human wrist. It uses a small-size permanent magnet of neodymium-iron-boron. The questions of whether a low-field spectrometer is sensitive enough to measure the phosphorus mineral content of bone and to what extent the phosphorus in soft tissue affects the measurement of bone mass are discussed


Microscale Magnetic Field Modulation For Enhanced Capture And Distribution Of Rare Circulating Tumor Cells, Peng Chen, Yu-Yen Huang, Kazunori Hoshino, John X.J Zhang Mar 2015

Microscale Magnetic Field Modulation For Enhanced Capture And Distribution Of Rare Circulating Tumor Cells, Peng Chen, Yu-Yen Huang, Kazunori Hoshino, John X.J Zhang

Open Dartmouth: Faculty Open Access Scholarship

Immunomagnetic assay combines the powers of the magnetic separation and biomarker recognition and has been an effective tool to perform rare Circulating Tumor Cells detection. Key factors associated with immunomagnetic assay include the capture rate, which indicates the sensitivity of the system, and distributions of target cells after capture, which impact the cell integrity and other biological properties that are critical to downstream analyses. Here we present a theoretical framework and technical approach to implement a microscale magnetic immunoassay through modulating local magnetic field towards enhanced capture and distribution of rare cancer cells. Through the design of a two-dimensional micromagnet ...


Interface Stress In Socket/Residual Limb With Transtibial Prosthetic Suspension Systems During Locomotion On Slopes And Stairs Jan 2015

Interface Stress In Socket/Residual Limb With Transtibial Prosthetic Suspension Systems During Locomotion On Slopes And Stairs

Faculty of Engineering University of Malaya

OBJECTIVE: This study aimed to compare the effects of different suspension methods on the interface stress inside the prosthetic sockets of transtibial amputees when negotiating ramps and stairs. DESIGN: Three transtibial prostheses, with a pin/lock system, a Seal-In system, and a magnetic suspension system, were created for the participants in a prospective study. Interface stress was measured as the peak pressure by using the F-socket transducers during stairs and ramp negotiation. RESULTS: Twelve individuals with transtibial amputation managed to complete the experiments. During the stair ascent and descent, the greatest peak pressure was observed in the prosthesis with the ...


Magnetic Resonance Imaging And Histology Correlation In The Neocortex In Temporal Lobe Epilepsy., Maged Goubran, Robert R Hammond, Sandrine De Ribaupierre, Jorge G Burneo, Seyed Mirsattari, David A Steven, Andrew G Parrent, Terry M Peters, Ali R Khan Jan 2015

Magnetic Resonance Imaging And Histology Correlation In The Neocortex In Temporal Lobe Epilepsy., Maged Goubran, Robert R Hammond, Sandrine De Ribaupierre, Jorge G Burneo, Seyed Mirsattari, David A Steven, Andrew G Parrent, Terry M Peters, Ali R Khan

Robarts Imaging Publications

OBJECTIVE: To investigate the histopathological correlates of quantitative relaxometry and diffusion tensor imaging (DTI) and to determine their efficacy in epileptogenic lesion detection for preoperative evaluation of focal epilepsy.

METHODS: We correlated quantitative relaxometry and DTI with histological features of neuronal density and morphology in 55 regions of the temporal lobe neocortex, selected from 13 patients who underwent epilepsy surgery. We made use of a validated nonrigid image registration protocol to obtain accurate correspondences between in vivo magnetic resonance imaging and histology images.

RESULTS: We found T1 to be a predictor of neuronal density in the neocortical gray matter (GM ...


In Vivo Mri Signatures Of Hippocampal Subfield Pathology In Intractable Epilepsy., Maged Goubran, Boris C Bernhardt, Diego Cantor-Rivera, Jonathan C Lau, Charlotte Blinston, Robert R Hammond, Sandrine De Ribaupierre, Jorge G Burneo, Seyed M Mirsattari, David A Steven, Andrew G Parrent, Andrea Bernasconi, Neda Bernasconi, Terry M Peters, Ali R Khan Jan 2015

In Vivo Mri Signatures Of Hippocampal Subfield Pathology In Intractable Epilepsy., Maged Goubran, Boris C Bernhardt, Diego Cantor-Rivera, Jonathan C Lau, Charlotte Blinston, Robert R Hammond, Sandrine De Ribaupierre, Jorge G Burneo, Seyed M Mirsattari, David A Steven, Andrew G Parrent, Andrea Bernasconi, Neda Bernasconi, Terry M Peters, Ali R Khan

Robarts Imaging Publications

OBJECTIVES: Our aim is to assess the subfield-specific histopathological correlates of hippocampal volume and intensity changes (T1, T2) as well as diff!usion MRI markers in TLE, and investigate the efficacy of quantitative MRI measures in predicting histopathology in vivo.

EXPERIMENTAL DESIGN: We correlated in vivo volumetry, T2 signal, quantitative T1 mapping, as well as diffusion MRI parameters with histological features of hippocampal sclerosis in a subfield-specific manner. We made use of on an advanced co-registration pipeline that provided a seamless integration of preoperative 3 T MRI with postoperative histopathological data, on which metrics of cell loss and gliosis were ...


Registration Of In-Vivo To Ex-Vivo Mri Of Surgically Resected Specimens: A Pipeline For Histology To In-Vivo Registration., Maged Goubran, Sandrine De Ribaupierre, Robert R Hammond, Catherine Currie, Jorge G Burneo, Andrew G Parrent, Terry M Peters, Ali R Khan Jan 2015

Registration Of In-Vivo To Ex-Vivo Mri Of Surgically Resected Specimens: A Pipeline For Histology To In-Vivo Registration., Maged Goubran, Sandrine De Ribaupierre, Robert R Hammond, Catherine Currie, Jorge G Burneo, Andrew G Parrent, Terry M Peters, Ali R Khan

Robarts Imaging Publications

BACKGROUND: Advances in MRI have the potential to improve surgical treatment of epilepsy through improved identification and delineation of lesions. However, validation is currently needed to investigate histopathological correlates of these new imaging techniques. The purpose of this work is to develop and evaluate a protocol for deformable image registration of in-vivo to ex-vivo resected brain specimen MRI. This protocol, in conjunction with our previous work on ex-vivo to histology registration, completes a registration pipeline for histology to in-vivo MRI, enabling voxel-based validation of novel and existing MRI techniques with histopathology.

NEW METHOD: A combination of image-based and landmark-based 3D ...