Mr. Geoffrey Hohert Profile

Geoffrey Hohert

Research Engineer at BC Cancer Research Ctr

SPIE Involvement:

Author

Area of Expertise:

OCT , Medical Imaging , Medical Device Design , 3D Printing , Optical Biopsy , Biopsy Guidance

Websites:

Company Website

Publications (19)

Proceedings Article | 13 March 2024 Presentation

Optical coherence tomography and autofluorescence guided biopsy of small airways using a suction-snare biopsy tool

Eric Brace, Jeanie Malone, Adrian Tanskanen, Geoffrey Hohert, Stephen Lam, Calum MacAulay, Pierre Lane

Proceedings Volume PC12820, PC128200H (2024) https://doi.org/10.1117/12.3003461

KEYWORDS: Biopsy, Optical coherence tomography, Autofluorescence, Lung, Tissues, Yield improvement, Vacuum chambers, Prototyping, Instrument modeling, Histopathology

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Proceedings Article | 9 March 2022 Presentation

Endoscopic optical coherence tomography (OCT) and autofluorescence imaging (AFI) of the endocervical canal for cervical cancer screening

Jeanie Malone, Sylvia Lam, Andrea Buenconsejo, Geoffrey Hohert, Dianne Miller, Lily Proctor, Sarah Finlayson, Gavin Stuart, Jessica McAlpine, Marette Lee, Calum MacAulay, Pierre Lane

Proceedings Volume PC11949, PC119490N (2022) https://doi.org/10.1117/12.2607646

KEYWORDS: Optical coherence tomography, Cervical cancer, Endoscopy, Auto-fluorescence imaging, Visualization, In vivo imaging, Biopsy, Tissues, Tissue optics, Oncology

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Proceedings Article | 7 March 2022 Presentation

W-type double clad fiber mitigates multipath artifacts in multimodal optical coherence tomography

Adrian Tanskanen, Jeanie Malone, Geoffrey Hohert, Pierre Lane

Proceedings Volume PC11948, PC1194810 (2022) https://doi.org/10.1117/12.2609965

KEYWORDS: Optical coherence tomography, Cladding, Endoscopy, Auto-fluorescence imaging, Tissues, Optical simulations, Imaging systems

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Proceedings Article | 7 March 2022 Presentation

Co-registered optical coherence tomography (OCT) and autofluorescence imaging (AFI) of ex vivo fallopian tubes for early ovarian cancer detection

Jeanie Malone, Geoffrey Hohert, Jessica McAlpine, Lien Hoang, Calum MacAulay, Pierre Lane

Proceedings Volume PC11952, PC1195206 (2022) https://doi.org/10.1117/12.2609994

KEYWORDS: Fallopian tube, Optical coherence tomography, Ovarian cancer, Auto-fluorescence imaging, Functional imaging, Cancer, Visualization, Tissues, Tissue optics, Surgery

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SPIE Journal Paper | 14 July 2021 Open Access

Small airway dilation measured by endoscopic optical coherence tomography correlates with chronic lung allograft dysfunction

Jeanie Malone, Anthony M. Lee, Geoffrey Hohert, Roland Nador, Pierre Lane

JBO, Vol. 26, Issue 07, 076005, (July 2021) https://doi.org/10.1117/12.10.1117/1.JBO.26.7.076005

KEYWORDS: Optical coherence tomography, Endoscopy, Lung, Optical testing, Pulmonary function tests, Diagnostics, Scattering, Biopsy, Visualization, Tissues

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SPIE Journal Paper | 20 October 2020 Open Access

Feasibility of combined optical coherence tomography and autofluorescence imaging for visualization of needle biopsy placement

Geoffrey Hohert, Renelle Myers, Sylvia Lam, Andrei Vertikov, Anthony Lee, Stephen Lam, Pierre Lane

JBO, Vol. 25, Issue 10, 106003, (October 2020) https://doi.org/10.1117/12.10.1117/1.JBO.25.10.106003

KEYWORDS: Biopsy, Optical coherence tomography, Tissues, Lung, In vivo imaging, Auto-fluorescence imaging, Diagnostics, Yield improvement, Visualization, Real time imaging

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Proceedings Article | 9 March 2020 Presentation

The impact of index dips in double clad fibers and endoscopic optical coherence tomography (Conference Presentation)

Adrian Tanskanen, Geoffrey Hohert, Pierre Lane

Proceedings Volume 11232, 1123205 (2020) https://doi.org/10.1117/12.2545063

KEYWORDS: Optical coherence tomography, Optical fibers, Endoscopy, Cladding, Imaging systems, Signal to noise ratio, Stray light, Superposition, Refractive index, Single mode fibers

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Proceedings Article | 17 February 2020 Presentation + Paper

Endoscopic optical coherence tomography (OCT) and autofluorescence imaging (AFI) of ex vivo fallopian tubes

Jeanie Malone, Geoffrey Hohert, Lien Hoang, Dianne Miller, Jessica McAlpine, Calum MacAulay, Pierre Lane

Proceedings Volume 11232, 1123202 (2020) https://doi.org/10.1117/12.2544475

KEYWORDS: Optical coherence tomography, Fallopian tube, Tissues, Ovarian cancer, Endoscopy, Cancer, Imaging systems, Fourier transforms, Auto-fluorescence imaging, Image analysis

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SPIE Journal Paper | 24 October 2019 Open Access

Submillimeter diameter rotary-pullback fiber-optic endoscope for narrowband red-green-blue reflectance, optical coherence tomography, and autofluorescence in vivo imaging

Andrea Louise Buenconsejo, Geoffrey Hohert, Max Manning, Elham Abouei, Reid Tingley, Ian Janzen, Jessica McAlpine, Dianne Miller, Anthony Lee, Pierre Lane, Calum MacAulay

JBO, Vol. 25, Issue 03, 032005, (October 2019) https://doi.org/10.1117/12.10.1117/1.JBO.25.3.032005

KEYWORDS: Reflectivity, Imaging systems, RGB color model, Optical coherence tomography, Endoscopes, Fiber optics, Endoscopy, Signal to noise ratio, Tongue, In vivo imaging

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Proceedings Article | 19 July 2019 Paper

Optical coherence tomography (OCT) imaging of chronic lung allograft dysfunction (CLAD)

Jeanie Malone, Anthony M. Lee, Geoffrey Hohert, Roland Nador, Pierre Lane

Proceedings Volume 11073, 110731J (2019) https://doi.org/10.1117/12.2527205

KEYWORDS: Optical coherence tomography, Lung, Visualization, Coherence imaging, Cancer, Transplantation, Biopsy, Bronchoscopy, Diagnostics, Surveillance

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Proceedings Article | 4 March 2019 Presentation

Sub-millimeter diameter high-resolution rotary-pullback fibre optic endoscope for RGB in-vivo imaging (Conference Presentation)

Andrea Louise Buenconsejo, Geoffrey Hohert, Ian Janzen, Anthony Lee, Pierre Lane, Calum MacAulay

Proceedings Volume 10854, 108540P (2019) https://doi.org/10.1117/12.2510772

KEYWORDS: Endoscopes, RGB color model, In vivo imaging, Fiber optics, Cancer, Signal to noise ratio, Oncology, Imaging systems, Prototyping, Image resolution

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Proceedings Article | 24 May 2018 Presentation

Dual-beam manually-actuated distortion-corrected imaging (DMDI) using galvanometer scanner (Conference Presentation)

Madeline Harlow, Anthony Lee, Geoffrey Hohert, Pierre Lane, Calum MacAulay

Proceedings Volume 10679, 106790B (2018) https://doi.org/10.1117/12.2306685

KEYWORDS: Scanners, Optical coherence tomography, Distortion, Interferometers, Calibration, Image resolution, Optical resolution, Optical imaging, Confocal microscopy, Multiphoton microscopy

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High resolution optical imaging modalities such as optical coherence tomography (OCT), confocal and multiphoton microscopy continue to show promise for diagnostic imaging. These imaging modalities commonly employ 2D scanning mechanisms that scan the sample in regular, pre-defined patterns. However, these scanners can often have limited in field-of-view and can be susceptible to artefacts due to patient or clinician motion. We have recently demonstrated a new imaging paradigm called dual-beam manually-actuated distortion-corrected imaging (DMDI) that overcomes these limitations. DMDI exploits the predictable path and spatial separation of two beams to calculate and correct the scanning distortion caused by manual actuation of the probe or the sample. DMDI was first implemented using a dual-beam micromotor catheter (DBMC) which could be useful for in vivo imaging of internal vessels, air ways, or tubular organs. Here, we present a new implementation of DMDI using a single axis galvanometer scanner. OCT imaging is used to demonstrate this implementation of DMDI. A single 1310nm swept source laser is split into two independent OCT interferometers. The two samples arms of the interferometers are aligned at different angles onto a single-axis galvo-mirror which is driven synchronously by the swept source. After passing through a scan lens, the scan pattern traced by the two beams is a pair of roughly parallel lines. A one-time calibration procedure is performed by imaging a phantom to precisely determine the beam separation and scanning pattern. Samples were scanned by manually moving them approximately perpendicular to the scan lines, acquiring two images. Using common, unique features in both of the images, the recorded time difference between the imaging of the features, and the calibrated relationship between the two beams, the image distortion caused by manually actuating the sample can be discerned, and the distortion-corrected images can be produced. To validate the galvanometer implementation of DMDI, we first imaged a phantom with a defined flat pattern. Image restoration was performed on the en face OCT images and showed distortion correction was feasible both perpendicular and parallel to the scan beam axis over a range of speeds. We also demonstrate correction for en face OCT images of a biological sample. DMDI is demonstrated as a versatile imaging modality as it can be adapted for different implementations. Although a bench top galvanometer scanner setup was used in this study this implementation could be adapted for imaging body sites such as the oral cavity or skin. Furthermore, OCT was chosen due to its availability in our lab, however in principle any point-scanning modality could be used for DMDI.

Proceedings Article | 24 April 2018 Paper

Motion artifacts in endoscopic catheter-based images: simulation and motion correction method

Elham Abouei, Anthony M. D. Lee, Hamid Pahlevaninezhad, Geoffrey Hohert, Michelle Cua, Pierre Lane, Stephen Lam, Calum MacAulay

Proceedings Volume 10711, 107110E (2018) https://doi.org/10.1117/12.2317400

KEYWORDS: Motion models, Modeling and simulation, Nonuniformity corrections, Optical coherence tomography, In vivo imaging, Endoscopy, 3D image processing, Image registration, Imaging systems, Data acquisition

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Proceedings Article | 14 March 2018 Presentation

OCT for lung transplantation monitoring: quantification of chronic lung allograft dysfunction (CLAD) biomarkers (Conference Presentation)

Geoffrey Hohert, Anthony Lee, Sylvia Lam, Pierre Lane, Calum MacAulay, Stephen Lam, Roland Nador, Robert Levy, John English

Proceedings Volume 10470, 104700A (2018) https://doi.org/10.1117/12.2291389

KEYWORDS: Lung, Optical coherence tomography, Biopsy, Transplantation, Computed tomography, Diagnostics, Endoscopy, Surveillance, Bronchoscopy, 3D image processing

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SPIE Journal Paper | 4 January 2018 Open Access

Correction of motion artifacts in endoscopic optical coherence tomography and autofluorescence images based on azimuthal en face image registration

Elham Abouei, Anthony M. D. Lee, Hamid Pahlevaninezhad, Geoffrey Hohert, Michelle Cua, Pierre Lane, Stephen Lam, Calum MacAulay

JBO, Vol. 23, Issue 01, 016004, (January 2018) https://doi.org/10.1117/12.10.1117/1.JBO.23.1.016004

KEYWORDS: Optical coherence tomography, In vivo imaging, 3D image processing, Endoscopy, Matrices, Visualization, Image registration, Atrial fibrillation, Tissues, Quantitative analysis

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Proceedings Article | 27 April 2016 Presentation

In vivo imaging of pulmonary nodule and vasculature using endoscopic co-registered optical coherence tomography and autofluorescence imaging (Conference Presentation)

Hamid Pahlevaninezhad, Anthony Lee, Geoffrey Hohert, Carely Schwartz, Tawimas Shaipanich, Alexander Ritchie, Wei Zhang, Calum MacAulay, Stephen Lam, Pierre Lane

Proceedings Volume 9691, 96910Y (2016) https://doi.org/10.1117/12.2209686

KEYWORDS: Optical coherence tomography, Auto-fluorescence imaging, Visualization, Endoscopy, In vivo imaging, Lung, Biopsy, Fiber optics, Tissues, Collagen

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Proceedings Article | 26 April 2016 Presentation

Endoscopic high-resolution auto fluorescence imaging and optical coherence tomography of airways in vivo (Conference Presentation)

Hamid Pahlevaninezhad, Anthony Lee, Geoffrey Hohert, Carley Schwartz, Tawimas Shaipanich, Alexander Ritchie, Wei Zhang, Calum MacAulay, Stephen Lam, Pierre Lane

Proceedings Volume 9701, 97010D (2016) https://doi.org/10.1117/12.2209726

KEYWORDS: Optical coherence tomography, In vivo imaging, Endoscopy, Auto-fluorescence imaging, Coherence imaging, Imaging systems, Visualization, Lung, Luminescence, Optical imaging

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Proceedings Article | 26 April 2016 Presentation

3D-printed phantom for the characterization of non-uniform rotational distortion (Conference Presentation)

Geoffrey Hohert, Hamid Pahlevaninezhad, Anthony Lee, Pierre Lane

Proceedings Volume 9700, 970007 (2016) https://doi.org/10.1117/12.2209638

KEYWORDS: Distortion, Imaging systems, Endoscopy, Tissues, Fused deposition modeling, 3D metrology, 3D modeling, Printing, Head, Stereoscopy

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Proceedings Article | 2 March 2015 Paper

Doppler optical coherence tomography and co-registered autofluorescence imaging of peripheral lung cancer

Wei Zhang, Alexander Ritchie, Hamid Pahlevaninezhad, Anthony Lee, Geoffrey Hohert, Lucas Cahill, Tawimas Shaipanich, Diana Ionescu, Calum MacAulay, Pierre Lane, Stephen Lam

Proceedings Volume 9304, 93040B (2015) https://doi.org/10.1117/12.2077848

KEYWORDS: Optical coherence tomography, Lung, Biopsy, Doppler tomography, Lung cancer, Blood vessels, Pathology, Atrial fibrillation, Bronchoscopy, Cancer

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Showing 5 of 19 publications

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