{"id":2092,"date":"2024-08-21T18:45:14","date_gmt":"2024-08-21T18:45:14","guid":{"rendered":"https:\/\/labs.cs.queensu.ca\/perklab\/?post_type=qsc_member&p=2092"},"modified":"2024-08-25T21:01:04","modified_gmt":"2024-08-25T21:01:04","slug":"colton-barr","status":"publish","type":"qsc_member","link":"https:\/\/labs.cs.queensu.ca\/perklab\/members\/colton-barr\/","title":{"rendered":"Colton Barr"},"content":{"rendered":"
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Colton Barr<\/h1><\/div>\n\t\t
MD\/PhD Student<\/div>\n\t\t
School of Computing<\/div>\n\t\t
Queen’s University<\/div>\n\t\t
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c.barr@queensu.ca<\/a><\/div>\n\t\t\t
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Biography<\/h2>\n\n\n\n

Colton Barr is an MD \/ PhD student in the School of Computing at Queen’s University supervised by Professor Gabor Fichtinger and Professor Parvin Mousavi. He is currently completing his second internship as a visiting researcher at the Golby Lab at Brigham and Women’s Hospital under the supervision of Dr. Alexandra Golby. His research interests lie at the intersection of surgical navigation, open-source software development and artificial intelligence, with a particular focus on building accessible solutions for deployment in limited-resource healthcare settings.<\/p>\n\n\n\n

Colton completed his BCompH at Queen’s in Biomedical Computing in 2019 and his MSc in Computing in 2022 at the Perk Lab.<\/p>\n\n\n\n

Publications<\/h2>\n\n\n
<\/a><\/form>

Farvolden, Coleman; Hashtrudi-Zaad, Kian; Connolly, Laura; Barr, Colton; Fichtinger, Gabor<\/p>

An accessible six-axis testbed for image-guided robotics research Journal Article<\/span> <\/p>

In: <\/span>vol. 13408, <\/span>pp. 458-463, <\/span>2025<\/span>.<\/p>

Abstract<\/a><\/span> | BibTeX<\/a><\/span><\/p>

@article{farvolden2025,
\r\ntitle = {An accessible six-axis testbed for image-guided robotics research},
\r\nauthor = {Coleman Farvolden and Kian Hashtrudi-Zaad and Laura Connolly and Colton Barr and Gabor Fichtinger},
\r\nyear  = {2025},
\r\ndate = {2025-01-01},
\r\nvolume = {13408},
\r\npages = {458-463},
\r\npublisher = {SPIE},
\r\nabstract = {PURPOSE: Cancer can recur after tumor resection surgery if tumor tissue is missed and left behind. We hypothesize that intraoperative robotic imaging could be used to inspect the surgical cavity and localize residual cancer tissue. This technique has the potential to improve the success rate of tumor resection surgery. Towards this, we propose and evaluate a benchtop testbed for robotic manipulation of an optical imaging probe. We use low-cost hardware and open-source software to construct the testbed and describe the implementation so that it can be easily adopted to support similar research. METHODS: We implemented a reusable, open-source module in 3D Slicer for reading position coordinates and motion planning with an inexpensive 6-axis robotic arm in Robot Operating System (ROS). For demonstration, a custom end-effector was used to fix an optical probe to the robot. The accuracy of the testbed \u2026},
\r\nkeywords = {},
\r\npubstate = {published},
\r\ntppubtype = {article}
\r\n}
\r\n<\/pre><\/div>
Close<\/a><\/p><\/div>
PURPOSE: Cancer can recur after tumor resection surgery if tumor tissue is missed and left behind. We hypothesize that intraoperative robotic imaging could be used to inspect the surgical cavity and localize residual cancer tissue. This technique has the potential to improve the success rate of tumor resection surgery. Towards this, we propose and evaluate a benchtop testbed for robotic manipulation of an optical imaging probe. We use low-cost hardware and open-source software to construct the testbed and describe the implementation so that it can be easily adopted to support similar research. METHODS: We implemented a reusable, open-source module in 3D Slicer for reading position coordinates and motion planning with an inexpensive 6-axis robotic arm in Robot Operating System (ROS). For demonstration, a custom end-effector was used to fix an optical probe to the robot. The accuracy of the testbed \u2026<\/div>
Close<\/a><\/p><\/div><\/div><\/div>
 Hashtrudi-Zaad, Kian;  Farvolden, Coleman;  Connolly, Laura;  Barr, Colton;  Fichtinger, Gabor<\/p>
Robotic tracking of a resection cavity using a low cost bench-top robotic arm and electromagnetics Journal Article<\/span> <\/p>
In: <\/span>vol. 13408, <\/span>pp. 217-222, <\/span>2025<\/span>.<\/p>
Abstract<\/a><\/span> | BibTeX<\/a><\/span><\/p>
@article{hashtrudi-zaad2025,
\r\ntitle = {Robotic tracking of a resection cavity using a low cost bench-top robotic arm and electromagnetics},
\r\nauthor = {Kian Hashtrudi-Zaad and Coleman Farvolden and Laura Connolly and Colton Barr and Gabor Fichtinger},
\r\nyear  = {2025},
\r\ndate = {2025-01-01},
\r\nvolume = {13408},
\r\npages = {217-222},
\r\npublisher = {SPIE},
\r\nabstract = {INTRODUCTION 
\r\nRoughly 40% of breast cancer patients are required to undergo corrective surgery after tumour resection via breast-conserving surgery (BCS). Sweeping of the cavity, resulting from the tumour resection, by spectroscopy and ultrasound imaging is emerging as a potential solution for identifying leftover cancer. However, the use of imaging modalities in the cavity is challenging as breast tissue is soft, malleable, and moves frequently. This paper presents and verifies an approach for tracking the relative motion of a resection cavity with a robotic arm. 
\r\nMETHODS 
\r\nWe use electromagnetic tracking and a low cost 6-axis robotic arm to track a simulated resection cavity. We embed an electromagnetic sensor in a 3D printed retractor that is designed to hold the cavity open. An open-source module in 3D Slicer is then used to detect cavity motion from the retractor and command the robotic arm to follow the \u2026},
\r\nkeywords = {},
\r\npubstate = {published},
\r\ntppubtype = {article}
\r\n}
\r\n<\/pre><\/div>
Close<\/a><\/p><\/div>
INTRODUCTION 
\r\nRoughly 40% of breast cancer patients are required to undergo corrective surgery after tumour resection via breast-conserving surgery (BCS). Sweeping of the cavity, resulting from the tumour resection, by spectroscopy and ultrasound imaging is emerging as a potential solution for identifying leftover cancer. However, the use of imaging modalities in the cavity is challenging as breast tissue is soft, malleable, and moves frequently. This paper presents and verifies an approach for tracking the relative motion of a resection cavity with a robotic arm. 
\r\nMETHODS 
\r\nWe use electromagnetic tracking and a low cost 6-axis robotic arm to track a simulated resection cavity. We embed an electromagnetic sensor in a 3D printed retractor that is designed to hold the cavity open. An open-source module in 3D Slicer is then used to detect cavity motion from the retractor and command the robotic arm to follow the \u2026<\/div>
Close<\/a><\/p><\/div><\/div><\/div>
 Elkind, Emese;  Barr, Keiran;  Barr, Colton;  Moga, Kristof;  Garamvolgy, Tivadar;  Haidegger, Tamas;  Ungi, Tamas;  Fichtinger, Gabor<\/p>
Modifying Radix Lenses to Survive Low-Cost Sterilization: An Exploratory Study<\/a> Conference<\/span> <\/p>
Imaging Network of Ontario (ImNO) Symposium, <\/span>2024<\/span>.<\/p>
Abstract<\/a><\/span> | Links<\/a><\/span> | BibTeX<\/a><\/span><\/p>
@conference{Elkind2024,
\r\ntitle = {Modifying Radix Lenses to Survive Low-Cost Sterilization: An Exploratory Study},
\r\nauthor = {Emese Elkind and Keiran Barr and Colton Barr and Kristof Moga and Tivadar Garamvolgy and Tamas Haidegger and Tamas Ungi and Gabor Fichtinger},
\r\nurl = {https:\/\/labs.cs.queensu.ca\/perklab\/wp-content\/uploads\/sites\/3\/2024\/10\/EmeseElkindImNO2024-2.docx},
\r\nyear  = {2024},
\r\ndate = {2024-03-19},
\r\nurldate = {2024-03-19},
\r\npublisher = {Imaging Network of Ontario (ImNO) Symposium},
\r\nabstract = {INTRODUCTION: A major challenge with deploying infrared camera-tracked surgical navigation solutions, such as NousNav [1], in low-resource settings is the high cost and unavailability of disposable retroreflective infrared markers. Developing an accessible method to reuse and sterilize retroreflective markers could lead to significant increase in the uptake of this technology. As none of the known infrared markers can endure standard autoclaving and most places do not have access to gas sterilization, attention is focused on cold liquid sterilisation methods commonly used in laparoscopy and other optical tools that cannot be sterilized in a conventional autoclave.
\r\nMETHODS: We propose to modify NDI Radix\u2122 Lens [1], single-use retroreflective spherical marker manufactured by Northern Digital, Waterloo, Canada. Radix lenses are uniquely promising candidates for liquid sterilization given their smooth, spherical surface. This quality also makes them easier to clean perioperatively compared to other retroreflective infrared marker designs. Initial experiments show that liquid sterilization agents degrade the marker\u2019s retroreflective gold coating (Fig. 1). Hence the objective of this project is to develop a method to protect the Radix Lenses with a layer of coating material that does not allow the sanitizing agent to degrade the coating to enable the lens to survive multiple sanitation cycles while retaining sufficient tracking accuracy. We employed two cold liquid sterilisation agents, household bleach which is a common ingredient of liquid sterilisation solutions and Sekusept\u2122 Aktiv (Ecolab, Saint Paul, MN, USA), which is widely known for sterilizing laparoscopy instruments. Store-bought nail polish and Zink-Alu Spray were used to coat the lenses. Data were obtained by recording five tests each with five rounds of sterilization, each tested with six trials, for a total of 150 recordings. The five tests were as follows: 1) Radix lens coated with nail polish and bleached, 2) uncoated and bleached, 3) coated with nail polish and sanitised, 4) uncoated and sanitised, and 5) coated with Zink-Alu Spray and sanitised. To assess the impact of the sterilization on the lens\u2019s fiducial localization error, two metal marker frames equipped with four sockets designed for the Radix lenses were used. The reference marker frame was secured to a flat table while the other marker frame moved along a fixed path on the table. The position and orientation of the marker clusters were streamed into 3D Slicer using the Public Library for Ultrasound Toolkit (PLUS). A plane was then fit to the recorded marker poses in 3D Slicer using Iterative Closest Point and the marker registration error was computed. Distance from the camera, angle of view, and distance from the edges of the field of view were held constant.
\r\nRESULTS: With each round of sterilization, the error of coated lenses was lower than the unprotected lenses, and the error showed a slightly increasing trend (Fig. 2). The lenses appeared fainter in the tracking software the lenses appeared fainter while all lenses remained trackable and visible despite the significant removal of reflective coating.
\r\nWhen reflective coating was fully rubbed off the lenses, the tracking software could still localize the markers; however, the lenses did appear much fainter in the tracking software.  We observed that the reflective coating rubs off the lens in routine handling, and recoating with Zink-Alu spray can partially restore marker visibility. Using protective nail polish coating prevented the reflective coating from rubbing off altogether. 
\r\nCONCLUSIONS: This exploratory study represents a promising step toward achieving low-cost sterilization of retroreflective infrared markers. Studies with the NousNav system need to be undertaken to measure the extent of degradation in tracking accuracy is tolerable as a side effect of marker sterilization. Before using coated Radix lenses on human subjects, it must be verified that the protective coating (common nail polish in our study) is fully biocompatible and remains undamaged by the cold sterilization agent (Sekusept\u2122 Aktiv in our study.) 
\r\nREFERENCES: [1] NousNav: A low-cost neuronavigation system for deployment in lower-resource settings, International Journal of Computer Assisted Radiology and Surgery, 2022 Sep;17(9):1745-1750. [2] NDI Radix\u2122 Lens (https:\/\/www.ndigital.com\/optical-measurement-technology\/radix-lens\/)  },
\r\nkeywords = {},
\r\npubstate = {published},
\r\ntppubtype = {conference}
\r\n}
\r\n<\/pre><\/div>
Close<\/a><\/p><\/div>
INTRODUCTION: A major challenge with deploying infrared camera-tracked surgical navigation solutions, such as NousNav [1], in low-resource settings is the high cost and unavailability of disposable retroreflective infrared markers. Developing an accessible method to reuse and sterilize retroreflective markers could lead to significant increase in the uptake of this technology. As none of the known infrared markers can endure standard autoclaving and most places do not have access to gas sterilization, attention is focused on cold liquid sterilisation methods commonly used in laparoscopy and other optical tools that cannot be sterilized in a conventional autoclave.
\r\nMETHODS: We propose to modify NDI Radix\u2122 Lens [1], single-use retroreflective spherical marker manufactured by Northern Digital, Waterloo, Canada. Radix lenses are uniquely promising candidates for liquid sterilization given their smooth, spherical surface. This quality also makes them easier to clean perioperatively compared to other retroreflective infrared marker designs. Initial experiments show that liquid sterilization agents degrade the marker\u2019s retroreflective gold coating (Fig. 1). Hence the objective of this project is to develop a method to protect the Radix Lenses with a layer of coating material that does not allow the sanitizing agent to degrade the coating to enable the lens to survive multiple sanitation cycles while retaining sufficient tracking accuracy. We employed two cold liquid sterilisation agents, household bleach which is a common ingredient of liquid sterilisation solutions and Sekusept\u2122 Aktiv (Ecolab, Saint Paul, MN, USA), which is widely known for sterilizing laparoscopy instruments. Store-bought nail polish and Zink-Alu Spray were used to coat the lenses. Data were obtained by recording five tests each with five rounds of sterilization, each tested with six trials, for a total of 150 recordings. The five tests were as follows: 1) Radix lens coated with nail polish and bleached, 2) uncoated and bleached, 3) coated with nail polish and sanitised, 4) uncoated and sanitised, and 5) coated with Zink-Alu Spray and sanitised. To assess the impact of the sterilization on the lens\u2019s fiducial localization error, two metal marker frames equipped with four sockets designed for the Radix lenses were used. The reference marker frame was secured to a flat table while the other marker frame moved along a fixed path on the table. The position and orientation of the marker clusters were streamed into 3D Slicer using the Public Library for Ultrasound Toolkit (PLUS). A plane was then fit to the recorded marker poses in 3D Slicer using Iterative Closest Point and the marker registration error was computed. Distance from the camera, angle of view, and distance from the edges of the field of view were held constant.
\r\nRESULTS: With each round of sterilization, the error of coated lenses was lower than the unprotected lenses, and the error showed a slightly increasing trend (Fig. 2). The lenses appeared fainter in the tracking software the lenses appeared fainter while all lenses remained trackable and visible despite the significant removal of reflective coating.
\r\nWhen reflective coating was fully rubbed off the lenses, the tracking software could still localize the markers; however, the lenses did appear much fainter in the tracking software.  We observed that the reflective coating rubs off the lens in routine handling, and recoating with Zink-Alu spray can partially restore marker visibility. Using protective nail polish coating prevented the reflective coating from rubbing off altogether. 
\r\nCONCLUSIONS: This exploratory study represents a promising step toward achieving low-cost sterilization of retroreflective infrared markers. Studies with the NousNav system need to be undertaken to measure the extent of degradation in tracking accuracy is tolerable as a side effect of marker sterilization. Before using coated Radix lenses on human subjects, it must be verified that the protective coating (common nail polish in our study) is fully biocompatible and remains undamaged by the cold sterilization agent (Sekusept\u2122 Aktiv in our study.) 
\r\nREFERENCES: [1] NousNav: A low-cost neuronavigation system for deployment in lower-resource settings, International Journal of Computer Assisted Radiology and Surgery, 2022 Sep;17(9):1745-1750. [2] NDI Radix\u2122 Lens (https:\/\/www.ndigital.com\/optical-measurement-technology\/radix-lens\/)  <\/div>
Close<\/a><\/p><\/div>