The PULSE Lab welcomes Ajay Gunalan. Ajay is a postdoctoral fellow who recently completed his PhD at the Italian Institute of Technology in Genoa, Italy. We are thrilled to have him as a the newest member of our team.
Welcome Ajay!
The PULSE Lab welcomes Ajay Gunalan. Ajay is a postdoctoral fellow who recently completed his PhD at the Italian Institute of Technology in Genoa, Italy. We are thrilled to have him as a the newest member of our team.
Welcome Ajay!
Congratulations to Junior Arroyo! His first-author publication is featured on the cover of Biophotonics Discovery. The figure is from the article “Predictive model for laser-induced tissue necrosis with immunohistochemistry validation” by J. Junior Arroyo, Arunima Sharma, Jiaxin Zhang, and Muyinatu A. Lediju Bell.
This work is the first to demonstrate a unified theoretical, computational, and experimental approach with quantitative immunohistochemistry (IHC) validation to determine laser safety for biological tissues other than skin or eyes. Although photoacoustic imaging has the potential to provide critical guidance in surgical interventions, its widespread use is challenged by the absence of applicable safety guidelines across diverse target tissues. Maximum permissible exposure (MPE) guidelines currently focus solely on skin and eyes. Results are promising to provide tissue-specific MPE guidelines to maintain healthy liver tissue during laser-based optical and photoacoustic surgeries and interventions. The presented approach and associated outcomes are promising for the introduction of tissue-specific safety guidelines for photoacoustic imaging and other optics-based imaging technologies that are designed to maximize signal-to-noise ratios while being designated as safe for patient use. In addition, the presented simulation framework and corresponding experimental protocols may be applied to other internal organs to achieve similar benefits.
Citation: Arroyo J, Sharma A, Zhang J, Bell MAL, Predictive model for laser-induced tissue necrosis with immunohistochemistry validation, Biophotonics Discovery 1(2):025003, 2024 [pdf]
Prof. Bell was invited to give the annual Lopez Lecture to a prestigious group of individuals who are members of the National Institutes of Health (NIH) National Advisory Council for Biomedical Imaging and Bioengineering. Her lecture took place on September 10, 2024, followed by Q&A with council members and awarding of a crystal memento from NIH National Institute of Biomedical Imaging and Bioengineering (NIBIB) Director Bruce Tromberg.
The National Advisory Council for Biomedical Imaging and Bioengineering advises the Department of Health and Human Services, the NIH, and the NIBIB on matters relating to the conduct and support of research, training, health information dissemination and other programs that address biomedical imaging, biomedical engineering and associated technologies and modalities with biomedical applications. Council members provide the second level review for all applications for funding of research and training grants or cooperative agreements by the NIBIB. The Council also advises on policy and program priorities.
This council meets three times per year, typically in January, May, and September. The September 2024 session was live-streamed and recorded, with the introduction to Prof. Bell’s lecture starting at the 2:55:30 timestamp of the NIH videocast: https://videocast.nih.gov/watch=54954.
The following PULSE Lab abstracts were accepted for presentation during the 2024 IEEE Ultrasonics, Ferroelectrics, and Frequency Control Joint Symposium (UFFC-JS) to be held September 22-26, 2024 in Taipei, Taiwain.
In addition, Md Ashikuzzaman will be presenting a poster on his solution to the a-MEM challenge.
Congrats to Jiaxin, Manik, Mahban, Junhao, Junior, Ashik, and Prof. Bell!
Symposium website: https://2024.ieee-uffc-js.org/
(updated September 19, 2024)
Welcome to four new PULSE Lab PhD students who recently joined us:
PhD Student, ECE
B.S., Bioengineering – University of California, Berkeley
PhD Student, ECE
M.Sc., Electrical Engineering – Syracuse University
B.Sc., Electromechanical Engineering – Addis Ababa Science and Technology University, Ethiopia
PhD Student, ECE
B.Sc., Electrical and Electronic Engineering – Bangladesh University of Engineering and Technology (BUET), Dhaka, Bangladesh
PhD Student, ECE
B.S., Electrical Engineering – New York University Abu Dhabi
Welcome Jamie, Haben, Jahin, and Julia! We wish you all the best as you each chart your course while undertaking this new PhD journey.
Congratulations to Md Ashikuzzaman! His first-author paper entitled MixTURE: L1-Norm-Based Mixed Second-Order Continuity in Strain Tensor Ultrasound Elastography was accepted for publication in IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control.
This work is the first to introduce an L1-norm-based second-order regularizer in a mechanically-inspired total strain tensor imaging framework named — L1-norm Mixed derivative for Total UltRasound Elastography — or, L1-MixTURE when abbreviated. Displacement tracking of ultrasound images can be implemented by optimizing a cost function consisting of a data term, a mechanical congruency term, and first- and second-order continuity terms. This approach recently provided a promising solution to two-dimensional axial and lateral displacement tracking in ultrasound strain elastography. However, the associated second-order regularizer only considers the unmixed second derivatives and disregards the mixed derivatives, thereby providing suboptimal noise suppression and limiting possibilities for total strain tensor imaging. We improved axial, lateral, axial shear, and lateral shear strain estimation quality by formulating and optimizing a novel L1-norm-based second-order regularizer that penalizes both mixed and unmixed displacement derivatives. Results are promising to advance the state-of-the-art in elastography-guided diagnostic and interventional decisions.
Citation: Ashikuzzaman M, Sharma A, Venkatayogi N, Oluyemi E, Myers K, Ambinder E, Rivaz H, Bell MAL, MixTURE: L1-Norm-Based Mixed Second-Order Continuity in Strain Tensor Ultrasound Elastography, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control (accepted August 13, 2024) [pdf]
Congratulations to Junior Arroyo! His first-author paper entitled Predictive model for laser-induced tissue necrosis with immunohistochemistry validation was accepted for publication in the newest SPIE journal, Biophotonics Discovery.
This work is the first to demonstrate a unified theoretical, computational, and experimental approach with quantitative immunohistochemistry (IHC) validation to determine laser safety for biological tissues other than skin or eyes. Although photoacoustic imaging has the potential to provide critical guidance in surgical interventions, its widespread use is challenged by the absence of applicable safety guidelines across diverse target tissues. Maximum permissible exposure (MPE) guidelines currently focus solely on skin and eyes. Results are promising to provide tissue-specific MPE guidelines to maintain healthy liver tissue during laser-based optical and photoacoustic surgeries and interventions. The presented approach and associated outcomes are promising for the introduction of tissue-specific safety guidelines for photoacoustic imaging and other optics-based imaging technologies that are designed to maximize signal-to-noise ratios while being designated as safe for patient use. In addition, the presented simulation framework and corresponding experimental protocols may be applied to other internal organs to achieve similar benefits.
Citation: Arroyo J, Sharma A, Zhang J, Bell MAL, Predictive model for laser-induced tissue necrosis with immunohistochemistry validation, Biophotonics Discovery 1(2):025003, 2024 [pdf]
Prof. Bell delivered the the NSF Waterman Awardee Distinguished Lecture on Equitable Medical Imaging on August 21, 2024, followed by Q&A with attendees. The session was live-streamed and recorded.
The recorded lecture is also available at the bottom of the webinar event page at this link: https://players.brightcove.net/679256133001/NkgrDczuol_default/index.html?videoId=6360892996112. This version has no lag in start time and includes videos of the co-hosts and presenter as they speak, but the upper right corner of slides are blocked by each speakers’ videos. The copy above has no speaker videos and as a result, none of the slides are blocked.
The PULSE Lab is thrilled to welcome research faculty member Dr. Mawia Khairalseed, who joins us with a PhD in Biomedical Engineering from Cairo University. Dr. Khairalseed has held multiple research positions at UT Dallas and Texas A&M University. Prior to these research appointments, Dr. Khairalseed was an Associate Professor in the Department of Biomedical Engineering at the Sudan University of Science and Technology in Khartoum, Sudan. He additionally served as Chair of the Department of Biomedical Engineering, Sudan University of Science and Technology from 2012-2016.
Welcome Dr. Khairalseed!
Prof. Bell delivered an outstanding invited talk to the President’s Council of Advisors on Science and Technology (PCAST) on July 11, 2024. She was the third speaker on a panel of three impressive back-to-back talks, presenting in the “Research and Researchers on the Horizon” session, followed by Q&A with PCAST. The session was live-streamed and recorded.
Agenda: https://www.whitehouse.gov/wp-content/uploads/2024/06/PUBLIC-AGENDA-JULY-2024-MEETING_as-of-28June-1.pdf
Speaker bios: https://www.whitehouse.gov/wp-content/uploads/2024/07/Speaker-Bios-Public-Sessions-July-11-2024.pdf
The PULSE Lab received a $115,000 TEDCO Technology Assessment Award from the Maryland Innovation Initiative to commercialize technology related to peripheral nerve injury. The project title is “A Non-invasive Imaging Device to Modernize Treatment of Peripheral Nerve Injury.”
Peripheral neuropathy occurs when the nerves that are located outside of the brain and spinal cord (peripheral nerves) are damaged. Causes of peripheral nerve injuries include injury from
accidents (sports), injury from medical conditions (autoimmune disease, diabetes, Guillain-Barre syndrome and carpal tunnel syndrome), and injury during surgical interventions. Severe nerve
injuries affect the sensory and motor functions, and lead to devastating impact on patient’s quality of life. The main treatment method of severe nerve damage is through nerve reconstruction
surgery. 250K patients are affected by peripheral nerve injury each year in the US and 150K are managed surgically. The choice of technique for surgical nerve repair is largely determined by nerve injury location. During surgery however, it is very difficult to establish the exact location and extent of a nerve injury. Viopsy will be the first commercially available device to quantify peripheral nerve viability intraoperatively and monitor nerve regeneration prior to target organ reinnervation. In doing so, this device is anticipated to transform the practice of peripheral nerve surgery. This work will be completed as a collaboration among Prof. Bell (PI), Sami Tuffaha, MD (co-investigator), and Shri Prabha Shivram (research specialist).
The PULSE Lab’s pioneering publications in this area include:
The foundational research to support this work was initially funded by a Johns Hopkins Discovery Award.
Welcome to the following new PULSE Lab members, including one master’s student and two undergraduate students, who have joined us this summer to work on various projects.
Bioengineering
Harvard University, Class of 2026
NSF-funded REU student
Biomedical Engineering
Brown University, Class of 2025
NSF-funded REU student
Welcome Taylor, Rhea, and Yanlin!
Congratulations to Md Ashikuzzaman! His paper, Deep learning-based displacement tracking for post-stroke myofascial shear strain quantification, was accepted for presentation at the IEEE International Symposium on Biomedical Imaging (ISBI), Athens, Greece, May 27-30, 2024. This peer-reviewed paper was also accepted for inclusion in the conference proceedings.
Congrats again on this significant achievement and milestone, Ashik!
Citation: M Ashikuzzaman, J Huang, S Bonwit, A Etemadimanesh, P Raghavan, MAL Bell, Deep learning-based displacement tracking for post-stroke myofascial shear strain quantification, IEEE International Symposium on Biomedical Imaging (ISBI), Athens, Greece, May 27-30, 2024
Prof. Bell was selected to receive the 2024 NSF Alan T. Waterman Award, which is the highest honor in the United States offered to early-career scientists and engineers. The award comes with a medal and $1,000,000 to advance each recipient’s research. Prof. Bell is the first ever recipient from Johns Hopkins University in the award’s 48-year history, which is a significant achievement for America’s first research university. Prof. Bell is also one of few women and Black scientists to receive the award. There is a lot of rich history behind this win.
When receiving this award, Prof. Bell was recognized “for pioneering innovations in ultrasound and photoacoustic imaging, particularly coherence-based beamforming, photoacoustic-guided surgery, and deep learning. These innovations cross interdisciplinary boundaries to improve medical image quality in patients, reduce patient deaths during surgery, inspire new surgical designs, and provide more equitable healthcare.” Congratulations to Prof. Bell!
Waterman Awardee Distinguished Lecture (delivered August 21, 2024)
The recorded lecture is also available at the bottom of the lecture event page at this link: https://players.brightcove.net/679256133001/NkgrDczuol_default/index.html?videoId=6360892996112
Congratulations to former PULSE Lab postdoc Lingyi Zhao! Her first-author journal paper entitled Detection of COVID-19 features in lung ultrasound images using deep neural networks was published in Communications Medicine, which is a Nature Publishing group journal). This paper is the first to demonstrate that simulations can be used to train deep neural networks to detect COVID-19 features in lung ultrasound images of patients. Therefore, DNNs trained with simulated and in vivo data are promising alternatives to training with only real or only simulated data when segmenting in vivo COVID-19 lung ultrasound features.
We offer public access (https://gitlab.com/pulselab/covid19) to the datasets and code described in the paper “Detection of COVID-19 features in lung ultrasound images using deep neural networks.” Communications Medicine, 2024. https://www.nature.com/articles/s43856-024-00463-5.
Access includes simulated B-mode images containing A-line, B-line, and consolidation features with paired ground truth segmentations, as well as our segmentation annotations of publicly available point of care ultrasound (POCUS) datasets (originating from https://github.com/jannisborn/covid19_ultrasound).
If you find our datasets and/or code useful, please cite the following references:
Three PULSE Lab abstracts were accepted to SPIE conferences this year.
SPIE Photonics West took place January 27- February 1, 2024, and the following work was presented by Jiaxin Zhang.
SPIE Medical Imaging is taking place February 18-22, 2024, and the following work was presented by Md Ashikuzzaman.
In addition to the above papers, Prof. Bell was invited to be a session chair at SPIE Photonics West for the the Advanced Biomedical and Clinical Diagnostic and Surgical Guidance Systems XXII, Session 6: Diffuse Reflectance Spectroscopy on January 28th from 11:00 AM-12:20 PM PST.
The PULSE Lab welcomes two postdocs, Deepak Raina (co-advised by Prof. Axel Krieger) and Pankaj Warbal. We also welcome PhD student Namitha Guruprasad.
Congratulations to Prof. Bell on being elected as a Fellow of Optica!
Optica, formerly the Optical Society of America (OSA), is the oldest preeminent professional society in the field of optics and photonics, uniting and educating scientists, engineers, educators, technicians and business leaders, with over 22,000 members from more than 180 countries and 45 Nobel Laureates in its ranks.
Optica Fellows are members who have served with distinction in the advancement of optics and photonics through distinguished contributions to education, research, engineering, business, and society. Fellows are selected by the society’s board of directors for this distinction, recognition, and honor, which is annually limited to approximately 0.5% of the society’s membership total at the time of election.
Prof. Bell is honored specifically “for pioneering contributions to photoacoustic imaging techniques and applications for surgical guidance.”
Optica News Release (Prof. Bell appears under surname “Lediju Bell” in this news release)
Research conducted by PULSE Lab visiting PhD student, Guilherme S. P. Fernandes, and co-advisor, Prof. Muyinatu Bell, is featured on CNN.
The topic of the feature is an algorithm that Prof. Bell invented as a graduate student, which is now revealing capabilities to address skin tone bias in photoacoustic imaging. When using this technique to image through skin with light, darker skin tones produce more acoustic clutter than lighter skin tones, which introduces unwanted biases (e.g., Black patients have worse images than white patients, leading to a disparity in the ability to see the important content needed to make an accurate diagnosis). The novel and innovative algorithm, termed short-lag spatial coherence (SLSC) beamforming, makes clearer pictures for all patients, regardless of skin tone. Prof. Bell collaborated with Prof. Theo Pavan and colleagues at the University of São Paulo in Brazil to test this algorithm on multiple volunteers, and the PULSE Lab hosted Guilherme over the past year to finalize this work, leading to the publication Mitigating skin tone bias in linear array in vivo photoacoustic imaging with short-lag spatial coherence beamforming.
SLSC beamforming was previously shown to reduce acoustic clutter in cardiac ultrasound images and in abdominal ultrasound images of patients with higher body mass indexes. The technique and its derivatives can also be used to clarify the fluid vs. solid content of indeterminate breast masses surrounded by dense breast tissue, thereby reducing unnecessary procedures and follow-ups when trying to detect breast cancer. Additional use cases include clarifying anatomical details in photoacoustic-guided surgery. These multiple examples demonstrate the expansive power, potential, and capabilities of designing more equitable imaging and healthcare technologies that serve a wider range of our global patient population.
Prof. Bell received a $1.5M NIH R01 grant from the National Institute of Biomedical Imaging and Bioengineering to support our project entitled, Photoacoustic Image Guidance of Hysterectomies. This project is motivated by the clinical challenges surrounding ureteral injury during hysterectomies, due to the close proximity of uterine arteries (which must be severed) and ureters (which must be preserved). Complications from accidental ureteral injuries include extensive repeat surgeries, complete kidney failure, sepsis, acute renal insufficiency, and patient death. The goal of this project is to establish optimal parameters to advance photoacoustic technology toward differentiation of ureters, uterine arteries, and tool tips during hysterectomies. This work will be completed in collaboration with primary co-investigator, Karen Wang, MD.
Four of our pioneering publications in this area include:
This work was initially funded by a Johns Hopkins Discovery Award.
Welcome to the following new PULSE Lab members, including five graduate students and two undergraduate students, who have joined us this fall to work on various projects.
PhD Student, ECE
B.Sc., Electrical and Control Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran
PhD Student, ECE
M.Sc., Physics, Indian Institute of Technology Gandhinagar, India
B.Sc. (HS), Physics & Electronics, Punjab University, Chandigarh, India
PhD Student, ECE
B.S., Electrical Engineering – Pennsylvania State University
PhD Student, CS
B.S., Biomedical Engineering – University of Texas at Austin, Austin, TX, US
PhD Student, ECE
M.S., Mechanical Engineering – ETH Zurich, Zurich, Switzerland
B.S., Physics & Mechanical Engineering – University of California, Santa Barbara, CA, US
Electrical Engineering (minor in Computer Integrated Surgery)
Johns Hopkins University, Class of 2025
Computational Neuroscience and English Double Major
Johns Hopkins University, Class of 2027
Welcome Neil, Nidhi, Junhao, Nethra, Gareth, Manik, and Mahban!
Welcome to Sara Ibrahim, Ahmed El-Desoky, and Adah Harding! Sara, Ahmed, and Adah are joining the PULSE Lab this summer as part of the LCSR Research Experience for Undergraduates (REU) program in Computational Sensing and Medical Robotics. They are pursuing undergraduate degrees at various universities across the country, with majors and minors in mechanical engineering, biology, computer science, chemistry, and music.
Sara, Ahmed, and Adah will be working with us for 10 weeks throughout the summer on projects in the areas of ultrasound imaging, photoacoustic imaging, and deep learning.
PULSE Lab alums Alycen Wiacek, PhD (ECE), Michelle Graham, PhD (ECE), and Eduardo Gonzalez, PhD (BME) returned to the Johns Hopkins University campus for the Whiting School of Engineering doctoral hooding ceremony on Monday, May 22, 2023. Current PULSE Lab members, families, and friends of the graduates attended the joyous celebration. Eduardo Gonzalez, PhD additionally participated in the the School of Medicine doctoral hooding ceremony for BME PhD graduates two days later on Wednesday, May 24, 2023.
We are thrilled for these bright and audacious PULSE Lab PhD pioneers, and we wish them well in all of their future endeavors!
The following PULSE Lab abstracts have been accepted for presentation during the 2023 IEEE International Ultrasonics Symposium (IUS) to be held September 3-8, 2023 in Montreal, Canada.
Congrats to Arunima, Guilherme, and José!
In addition to co-authoring the above publications:
Symposium website: https://2023.ieee-ius.org/
(This post was updated on September 4, 2023)
The PULSE Lab welcomes Md Ashikuzzaman (Ashk). Ashik is a postdoctoral fellow who recently completed his PhD at Concordia University. We are thrilled to have him as a the newest member of our team.
Welcome Ashik!
Congratulations to Prof. Bell on being elected as a Fellow of SPIE! SPIE Fellows are are members of distinction who have made significant scientific and technical contributions in the multidisciplinary fields of optics, photonics, and imaging and are honored for their technical achievements, service to the general optics community, and service to SPIE.
Prof. Bell was recognized for her “achievements in photoacoustic imaging techniques and applications for surgical guidance.” She is a regular attendee and author of two SPIE communities and was honored as a new 2023 Fellow within both communities. Prof. Bell received her SPIE Fellow pin and certificate at SPIE Photonics West, presented by Symposium Chair Jennifer Barton and SPIE President Bernard Kress. Three weeks later, she was honored with a Fellow certificate presentation at SPIE Medical Imaging, delivered by Symposium Chair Despina Kontos.
Congratulations to PULSE Lab summer undergraduate student Khadijat Kokumo, who won the Best Paper Award runner up at the 2023 SPIE Physics of Medical Imaging conference! This conference features a student paper award specifically to recognize outstanding papers in development and application of medical imaging and diagnosis.
Khadijat’s first-author paper, entitled “Theoretical basis and experimental validation of harmonic coherence-based ultrasound imaging for breast mass diagnosis,” describes and summarizes research she completed in summer 2022 as a CSMR REU student from Northwestern University.
The award is sponsored by Konica Minolta, and it was presented to Khadijat by John Sabol from Konica Minolta Healthcare Americas, Inc. Lifeng Yu (Mayo Clinic) and Rebecca Fahrig (Siemens Healthcare GmBH) are the conference chairs. Prof. Bell is the senior author of the paper.
Two PULSE Lab abstracts were accepted to SPIE conferences this year.
SPIE Photonics West is taking place January 28- February 2, 2023, and the following work was presented by Jiaxin Zhang.
SPIE Medical Imaging will take place February 20-24, 2023, and the following work will be presented by Khadijat Kokumo.
The PULSE Lab also contributed to the following two collaborative works, which will also be presented at SPIE Medical Imaging.
In addition to the above papers, Prof. Bell was invited to be a session chair at SPIE Photonics West for the the Advanced Biomedical and Clinical Diagnostic and Surgical Guidance Systems XXI, Session 8: Novel Techniques on January 29th from 3:40-5:20 PM PST and for Multiscale Imaging and Spectroscopy IV, Session 7: Emerging Sources of Multiscale Contrast II on January 29th from 1:20 – 3:10 PM PST.
Prof. Bell was selected to receive the 2022 IEEE Ultrasonics Early Career Investigator Award, which was announced on at the IEEE International Ultrasonics Symposium in Venice, Italy. This award recognize the achievements of a young researcher in the area of ultrasonics and its applications. Prof. Bell was recognized for “pioneering contributions to spatial coherence beamforming theory and deep learning methods for ultrasound and photoacoustic image formation.”
Congratulations to Prof. Bell on winning the inaugural Science Diversity Leadership Award!
This $1.15 million award is offered by the Chan Zuckerberg Initiative (CZI) in partnership with the National Academies of Sciences, Engineering, and Medicine to launch this program. The award recognizes and furthers the leadership and scientific accomplishments of excellent biomedical researchers who—through their outreach, mentoring, and teaching—have a record of promoting diversity, equity and inclusion in their scientific fields. Recipients will additionally connect with each other and international scientific leaders through
gatherings over the course of the five years.
Congratulations to Prof. Bell on winning the 2022 Johns Hopkins Catalyst Award!
Awarded to 38 early-career faculty this year, across all divisions within Johns Hopkins, the Catalyst Award honors the accomplishments, creativity, originality, and academic impact of its recipients. The award provides a $75,000 grant to conduct preliminary studies with the eventual goal of redefining laser safety for photoacoustic-guided liver surgery. In addition to the grant, the award comes with mentoring opportunities and institutional recognition.
Two of our pioneering journal publications in this area include:
It is a huge honor to be a recipient of this award, and all recipients will be celebrated at a university-sponsored event taking place on October 20, 2022! Congrats again to Prof. Bell!
The following PULSE Lab abstracts were accepted for presentation during the 2022 IEEE International Ultrasonics Symposium (IUS) to be held October 10-13, 2022 in Venice, Italy.
Congrats to Prof. Bell, Jiaxin, Arunima, Lingyi, Mardava, and Guilherme!
In addition to co-authoring the above publications:
Symposium website: https://2022.ieee-ius.org/
Prof. Bell received a $1.4M NIH R01 grant from the National Institute of Biomedical Imaging and Bioengineering to support our project entitled, Minimizing Uncertainty in Breast Ultrasound Imaging with Real-Time Coherence-Based Beamforming. This project is motivated by the clinical challenges surrounding ultrasound images yielding inconclusive results in a subset of patients, necessitating biopsies, aspirations, or follow-up imaging, which increase patient anxiety and places additional burdens on the time available for clinical care and the resource allocations of our healthcare system. The goal of this project is to develop new, real-time ultrasound imaging technology that will simplify clinical workflows by distinguishing fluid-filled masses from solid masses and from complex cystic and solid masses, which all appear hypoechoic in traditional ultrasound B-mode images. This work will be completed in collaboration with breast radiologists Eniola Oluyemi, MD, Kelly Myers, MD, Emily Ambinder, MD, and Lisa Mullen, MD.
Three of our pioneering journal publications in this area include:
This work has also been featured in the following articles and press releases:
We additionally have a pending patent for these ideas.
Congratulations to PULSE Lab member Dr. Eduardo González! He successfully defended his PhD dissertation on September 26, 2022. His defense presentation was entitled Ultrasound and Photoacoustic Techniques for Surgical Guidance Inside and Around the Spine. Eduardo intends to pursue a career in industry, starting with post-academic training with Philips (one of the three major manufacturers of ultrasound imaging systems), with an offer to start in mid-October.
Congratulations to Eduardo González! His first author paper entitled, Dual-wavelength photoacoustic atlas method to estimate fractional methylene blue and hemoglobin contents, was accepted to the Journal of Biomedical Optics.
This work discusses a novel approach to estimate concentration levels from a mixture of two photoacoustic-sensitive materials after only two laser wavelength emissions. The work builds on our previously proposed acoustic atlas alternative to spectral unmixing, and it is the first to present an acoustic-based photoacoustic estimator that relies on training sets to estimate concentration levels from mixtures of photoacoustic-sensitive materials. Results are promising for real-time monitoring of the concentration of contrast agents in the operating room.
Citations:
González EA, Bell MAL, Dual-wavelength photoacoustic atlas method to estimate fractional methylene blue and hemoglobin contents, Journal of Biomedical Optics, 27(9):096002, 2022 [pdf]
González EA, Graham CA, Bell MAL, Acoustic frequency-based approach for identification of photoacoustic surgical biomarkers, Frontiers in Photonics, 2, 2021 [pdf]
Related News:
Welcome to Guilherme S. P. Fernandes! Guilherme is joining the PULSE Lab for one year as a visiting PhD student from the University of São Paulo, advised by Prof. Theo Pavan. His visit is supported by the Brazilian foundation FAPSEP.
Visiting PhD Student from University of São Paulo, Brazil B.S., Medical Physics, University of São Paulo, Ribeirao Preto – SP, Brazil
Guilherme and Prof. Bell initially met at SPIE Photonics West in 2020 when Prof. Bell visited his research poster.
Welcome to Khadijat Kokumo! Khadijat is joining the PULSE Lab this summer as part of the LCSR Research Experience for Undergraduates (REU) program in Computational Sensing and Medical Robotics. She hails from Atlanta, GA and is pursuing an undergraduate degree at Northwestern University.
Khadijat will be working with us for 10 weeks throughout the summer on an exciting project in the area of spatial coherence ultrasound beamforming.
Congratulations to PULSE Lab member Dr. Alycen Wiacek! She successfully defended her PhD dissertation on June 1, 2021. Her defense presentation was entitled Coherence-Based Ultrasound and Photoacoustic Imaging with Applications in Breast Mass Diagnosis and Hysterectomy Guidance. Alycen secured a tenure-track Assistant Professor position at her alma mater, Oakland University, and her post-graduate plans are to assume this new position in Fall 2022.
Prof. Bell was installed as the John C. Malone Professor on Monday, May 16, 2022. The John C. Malone Professorship was endowed through the generosity of John C. Malone ’64, ’69 to support outstanding Whiting School faculty members within the Malone Center for Engineering in Healthcare. Family, friends, colleagues, and students gathered together to celebrate this momentous occasion. The event was live-streamed, and the recording is available on YouTube.
Congratulations to Mardava Gubbi! His first-author paper entitled Theoretical Framework to Predict Generalized Contrast-to-Noise Ratios of Photoacoustic Images With Applications to Computer Vision was accepted for publication in IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control.
This work is the first to the first to present a novel framework to establish relationships among photoacoustic imaging system parameters, image quality, and computer vision-based task performance. Our framework leverages gCNR to quantify the relationships between system parameters (e.g., channel SNR, laser energy) and photoacoustic image quality. Within this framework, we present a theoretical derivation of gCNR predictions based on using the statistics of the target and background signal powers, then validate these predictions on simulated, experimental, and in vivo data. This framework was then leveraged to quantify the accuracy of a photoacoustic target segmentation algorithm as a function of gCNR and demonstrate the robustness of gCNR to thresholding, with possible extensions to other computer vision-based tasks (e.g., target tracking and image classification) and to improve the overall photoacoustic imaging system design process.
Citation: Gubbi MR, Gonzalez EA, Bell MAL,Theoretical Framework to Predict Generalized Contrast-to-Noise Ratios of Photoacoustic Images With Applications to Computer Vision,” IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 69(6):2098-2114, 2022 [pdf]
We are thrilled to welcome PULSE Lab alum Arun Nair, PhD back to the university campus for the Whiting School of Engineering doctoral hooding ceremony! Congratulations to Dr. Nair on this momentous occasion!
Congratulations to Mardava Gubbi on his successful completion of the ECE Department preliminary thesis research proposal and seminar requirement!
The topics discussed in Mardava’s seminar are summarized in the following peer-reviewed publications:
Congratulations to Alycen Wiacek for winning the New Investigator Award from the American Institute of Ultrasound in Medicine (AIUM)! Alycen was selected to present her research in the New Investigator Scientific Session Plenary at the AIUM 2022 Annual Meeting. She discussed her three first-author papers on the clinical implications of spatial coherence features for breast ultrasound:
Alycen was selected as the winner of this symposium, alongside Prof. Brooks Lindsey from Georgia Institute of Technology.
Congratulations to Prof. Muyinatu Bell on her election to the American Institute for Medical and Biological Engineering (AIMBE) College of Fellows! AIMBE Fellows represent the top 2% of medical and biological engineers. In addition, Prof. Bell is one of only four Assistant Professors to be elected at this career stage, out of 1,500 fellows elected in the past 10 years! This significant achievement highlights Prof. Bell’s outstanding research contributions and impactful advocacy for her field.
Prof. Bell was nominated, reviewed, and elected by peers and members of the AIMBE College of Fellows for pioneering contributions to development of ultrasonic and photoacoustic medical imaging systems, including coherence-based beamforming, photoacoustic-guided surgery, and deep learning applications.
Prof. Bell and Lingyi Zhao co-authored an invited review entitled, A Review of Deep Learning Applications in Lung Ultrasound Imaging of COVID-19 Patients, which was recently published in BME Frontiers.
This review is focused on deep learning applications in lung ultrasound imaging of COVID-19 and provides a comprehensive overview of ultrasound systems utilized for data acquisition, associated datasets, deep learning models, and comparative performance..
Citation: Lingyi Zhao, Muyinatu A. Lediju Bell, “A Review of Deep Learning Applications in Lung Ultrasound Imaging of COVID-19 Patients“, BME Frontiers, vol. 2022, Article ID 9780173, 17 pages, 2022. https://doi.org/10.34133/2022/9780173
Published less than two years ago in June 2020, Application of the generalized contrast-to-noise ratio to assess photoacoustic image quality received the honor of being a top-cited paper in the journal Biomedical Optics Express in January 2022. This paper investigates a newly developed, probability-based, generalized contrast-to-noise (gCNR) when applied to photoacoustic images. We recommend gCNR as a new standard for assessment of novel photoacoustic beamforming and image formation techniques.
Congratulations to Kelley, Michelle, Mardava, Theron, and Prof. Bell for contributing this foundational development for the photoacoustics and biomedical optics community!
Four PULSE Lab abstracts were accepted to various SPIE conferences this year.
SPIE Photonics West took place January 22-27, 2022, and the following work was presented by Michelle and Eduardo.
PULSE Lab PhD candidates Michelle Graham and Eduardo Gonzalez delivered two poster presentations at SPIE @PhotonicsWest this year. I was unable to attend, but I enjoyed seeing all of the updates, and I hope to return next year! pic.twitter.com/eYEDqEIGCv
— Bisi Bell (@MuyinatuBell) January 27, 2022
SPIE Medical Imaging will take place February 20-24, 2022, and the following work will be presented by Ben Frey.
In addition, Prof. Bell was invited to speak at SPIE Optics + Photonics, which will take place August 22-25, 2022, where she will deliver the presentation:
GEN Biotechnology is a new peer-reviewed journal launching in early 2022, focused on exceptional groundbreaking research across all aspects of biotechnology. Prof. Bell is one of the inaugural members of the Editorial Advisory Board. Submission instructions for your groundbreaking biotechnology research that validates and showcases advances in technology development and scientific and medical applications are available here.
Congratulations to Eduardo González! His first-author paper entitled Acoustic Frequency-Based Approach for Identification of Photoacoustic Surgical Biomarkers was accepted for publication in the journal Frontiers in Photonics.
This paper demonstrates a novel approach to accurately identify biological markers by analyzing the acoustic frequency response from either a single-wavelength emission (i.e., single-wavelength atlas method) or two consecutive wavelength emissions (i.e., dual-wavelength atlas method). The proposed approach relies on training sets to identify photoacoustic-sensitive materials, is robust against changes in fluence levels, and has comparable sensitivity, specificity, and accuracy to those obtained with conventional and enhanced spectral unmixing methods. This paper is part of the journal’s research topic Biophotonics Technologies for Clinical Translation.
Citation: González EA, Graham CA, Bell MAL, Acoustic frequency-based approach for identification of photoacoustic surgical biomarkers, Frontiers in Photonics, 2, 2021 [pdf]
The PULSE Lab welcomes Arunima Sharma, Junior Arroyo, and Jiaxin Zhang.
Arunima is a postddoctoral fellow who received her Ph.D. degree in Biomedical Engineering from Nanyang Technological University, Singapore.
Junior joins us from the Pontifical Catholic University of Peru in Lima, Peru, where he completed an M.S. degree in Digital Signal and Image Processing and a B.S. degree in Physics. He is a matriculating PhD student in the BME Department.
Congratulations to Mardava Gubbi for successfully disseminating his work to the general public at the 2021 Maryland STEM Festival! The event was live streamed with the recording now available on Youtube. Mardava was the first of 5 presenters.
Mardava describes work that was also presented to a technical audience at the 2021 IEEE International Conference on Robotics and Automation (ICRA). His associated peer-reviewed conference paper is entitled, “Deep Learning-Based Photoacoustic Visual Servoing: Using Outputs from Raw Sensor Data as Inputs to a Robot Controller.”
Alycen Wiacek and Jessica Su each received the distinction of being selected as scholars of the Achievement Rewards for College Scientists (ARCS) Foundation, Metropolitan Washington Chapter, for the 2021-2022 academic year. Jessica is the 2021-2022 Bill & Marilynn Sweetser Undergraduate Scholar. Alycen is the 2021-2022 JCM Foundation Graduate Scholar. Congratulations Alycen and Jessica!
Prof. Bell is a featured IEEE TMI Associate Editor for the month of October! Check out her profile here.
Congratulations to Alycen Wiacek! She was named to the 2022 Class of Siebel Scholars — a highly selective group of individuals representing the top graduate students in the world. Alycen was recognized in the bioengineering category, and she is the only student not enrolled in the JHU BME PhD program to be recognized in this category this year. Alycen is also the first JHU ECE PhD student to receive this outstanding recognition.
The following PULSE Lab abstracts were accepted for presentation during the 2021 IEEE International Ultrasonics Symposium (IUS) to be held on September 11-16, 2021 online (due to COVID-19).
Congrats to Alycen, Eduardo, Michelle, Kelley, and Mardava!
In addition to co-authoring the above publications:
Symposium website: https://2021.ieee-ius.org
Congrats to Benjamin Frey! He was our summer Research Experience for Undergraduates (REU) student who conducted a virtual summer research project with us. His research topic was centered on deep learning applied to lung ultrasound imaging of COVID-19 patients. His outstanding work earned him a second place presentation award at the 2021 Computational Sensing and Medical Robotics (CSMR) REU Final Presentations Award Ceremony. Ben joins a long list of PULSE Lab REU students to win this award.
Special thanks to Ben’s postdoc mentor, Lingyi Zhao, for helping to make Ben’s project such a resounding success!
Welcome to Camryn Graham and Ben Frey! Camryn and Ben are joining the PULSE Lab this summer as part of the LCSR Research Experience for Undergraduates (REU) program in Computational Sensing and Medical Robotics. They are pursuing undergraduate degrees at universities located in the midwest.
Camryn and Ben will be working with us for 10 weeks throughout the summer on projects in the area of ultrasound and photoacoustic imaging.
Within its first month of publication, Photoacoustic-Guided Surgery from Head to Toe, an invited review co-authored by Alycen Wiacek and Prof. Bell, received the honor of being a top 10 download from the journal Biomedical Optics Express. This invited review covers multiple aspects of the use of photoacoustic imaging to guide both surgical and related non-surgical interventions and includes a discussion of complete systems and tools needed to maximize success.
Congratulations to Alycen and Prof. Bell for capturing the attention of the biomedical optics community!
Congratulations to PULSE Lab member Dr. Arun Nair! He successfully defended his PhD dissertation on May 25, 2021. Arun was co-advised by ECE Profs. Bell and Tran. His defense presentation was entitled Machine Learning for Beamforming in Ultrasound, Radar, and Audio. Arun, his fellow labmates, and his co-advisors celebrated with an outdoor dinner and a delicious cake creation from PULSE Lab member Kelley Kempski. Arun’s post-graduate plans are to work for Amazon, Inc. in the Bay area.
Prof. Bell delivered a total of 17 invited talks to date in 2021 (compared to 13 in 2020 and over 70 talks total). Here is a summary of the 2020-2021 talk titles, dates, and locations, with additional highlights, announcements, and links to recordings wherever available:
2021
2020
Excellent invited talk by @MuyinatuBell at @RyersonSci on her work on #photoacoustic imaging. After the talk a @iBESTResearch lab tour to showcase work of @RyersonGraduate students. Also, a 500+ page Ph.D. thesis snuck in the discussions 😮 #research #bioengineering pic.twitter.com/3w78saj5VX
— Michael Kolios (@MichaelKolios) March 2, 2020
CANCELLED or POSTPONED DUE TO COVID-19
Congratulations to Alycen Wiacek! Her first-author paper entitled Photoacoustic-guided laparoscopic and open hysterectomy procedures demonstrated with human cadavers was accepted for publication in IEEE Transactions on Medical Imaging.
This work is the first to demonstrate a novel method for photoacoustic image-guided hysterectomies within the realistic imaging environment of a human cadaver during both open and laparoscopic procedures. With a contrast agent injected into the ureter, two laser wavelengths can be used to create a simultaneous display of the ureter and the uterine artery. This dual-wavelength approach was then integrated to create a novel surgical guidance system by estimating the tool-to-ureter distance and mapping that distance to an audible signal, similar to the parking sensor on a modern automobile. This auditory signal is intended to alert surgeons who are operating too closely to the ureter, which can lead to multiple life-threatening complications caused by accidental injury to the ureter during surgery.
Citation: Wiacek A, Wang KC, Wu H, Bell MAL, Photoacoustic-guided laparoscopic and open hysterectomy procedures demonstrated with human cadavers, IEEE Transactions on Medical Imaging (accepted May 13, 2021) [pdf]
Congratulations to Michelle Graham on her successful completion of the ECE Department preliminary thesis research proposal and seminar requirement!
Details about Michelle’s proposal seminar are available here: https://engineering.jhu.edu/ece/events/thesis-proposal-michelle-graham/?instance_id=1075#.YLSFAS33ZOk.
The topics discussed in Michelle’s seminar are summarized in the following publications:
Journal Articles
Conference Proceedings
Prof. Bell and Alycen Wiacek co-authored an invited review entitled, Photoacoustic-Guided Surgery from Head to Toe, which was recently published in Biomedical Optics Express.
This review covers multiple aspects of photoacoustic imaging to guide surgical & related non-surgical interventions, including a discussion of complete systems and tools needed to maximize success.
Citation: Alycen Wiacek and Muyinatu A. Lediju Bell, “Photoacoustic-guided surgery from head to toe [Invited],” Biomed. Opt. Express 12, 2079-2117 (2021) [bibtex]
Congratulations to Prof. Bell! She was appointed as the John C. Malone Assistant Professor of Electrical and Computer Engineering, Biomedical Engineering, and Computer Science, effective March 15, 2021.
Congratulations to Alycen Wiacek on her successful completion of the ECE Department preliminary thesis research proposal and seminar requirement!
Details about Alycen’s proposal seminar are available here: https://engineering.jhu.edu/ece/events/thesis-proposal-alycen-wiacek/?instance_id=1066#.YGna5khKi8o.
The topics discussed in Alycen’s seminar are summarized in the following publications:
Journal Articles
Conference Proceedings
Congratulations to Reese Dunne, our 2020 summer REU student, who was recently selected to receive the 2021 Barry S. Goldwater Scholarship! The Goldwater Scholarship Program is one of the oldest and most prestigious national scholarships in the natural sciences, engineering, and mathematics in the United States. This program seeks to identify and support college sophomores and juniors who show exceptional promise of becoming the nation’s next generation of research leaders.
After completing summer research in the PULSE Lab through our NSF-Funded CSMR REU Program, Reese returned to complete his undergraduate studies at Mississippi State University. Reese is now his university’s only Goldwater Scholar in 2021 and his university’s 6th winner since 2012. Reese’s additional successes since departing from our program and winning the program’s 2nd Best Presentation Award include winning the 2nd place award in the Biological Sciences and Engineering category at his school’s Fall 2020 Undergraduate Research Symposium and winning the Best Oral Presentation award in the STEM category at his state-wide Mississippi Honors Undergraduate Conference. Reese presented his summer research with us to secure these outstanding wins.
Mississippi State University News (re: Goldwater)
Mississippi State University News (re: Undergraduate Research Symposium)
Congratulations to Mardava Gubbi! His paper, Deep Learning-Based Photoacoustic Visual Servoing: Using Outputs from Raw Sensor Data as Inputs to a Robot Controller, was accepted for presentation at the IEEE International Conference on Robotics and Automation (ICRA), Xi’an, China, May 30 – June 5, 2021. This peer-reviewed paper was also accepted for inclusion in the conference proceedings.
ICRA is the IEEE Robotics and Automation Society’s flagship conference and the premier international forum for robotics researchers to present and discuss their work.
Congrats again on this significant achievement, recognition, and milestone, Mardava!
The PULSE Lab welcomes postdoc Lingyi Zhao. Lingyi received a PhD from the Georgia Tech/Emory/Peking University joint Ph.D. program in Biomedical Engineering. Prior to that, she received a B.S. degree in Physics with a minor in Acoustics from Nanjing University in Nanjing, China. Welcome Lingyi!
Five PULSE Lab abstracts were accepted to SPIE Photonics West. This conference is taking place virtually, March 6-11, 2021.
This work spans two tracks within the SPIE Photonics West BiOS Conference:
In addition to these five PULSE Lab contributions:
Prof. Bell was invited to give a seminar to the Bioengineering Department at the University of Washington on February 11, 2020. The seminar was entitled, Listening to the Sound of Light to Guide Surgeries.
Prof. Bell was invited to deliver a plenary presentation at the IEEE EMBS Grand Challenges Symposium on Medical Imaging on February 10, 2020. The presentation was entitled, Ultrasound Image Formation in the Deep Learning Age.
Prof. Bell co-authored a publication in the scientific journal Cell with fellow colleagues at 15 institutions across the nation to shed light on NIH funding disparities. The publication is entitled Fund Black Scientists. All academics are encouraged to read it, digest the contents, and reflect on what we each want our role to be at this historic moment in time.
Congratulations to Prof. Bell, who was selected to receive the 2021 SPIE Early Career Achievement Award. This award recognizes excellence in academia, particularly with regard to significant and innovative technical contributions in the engineering or scientific fields of relevance to SPIE. The SPIE Awards Committee made this recommendation in recognition of Prof. Bell’s pioneering contributions to photoacoustic imaging for surgical guidance, including innovative technology designs, novel deep learning applications, informative spatial coherence beamforming theory, and visionary clinical possibilities.
Congratulations to Eduardo González! His first-author journal paper entitled Combined ultrasound and photoacoustic image guidance of spinal pedicle cannulation demonstrated with intact ex vivo specimens was accepted to the journal IEEE Transactions on Biomedical Engineering.
This paper presents the first known combined ultrasound and photoacoustic image guidance system with software capabilities that are optimized for pedicle cannulation in posterior spinal fusion surgery. We demonstrate that both amplitude- and coherence-based beamforming methods are mutually beneficial for this task. Specifically, coherence-based beamforming of ultrasound images improved the visualization of bone for ultrasound-to-CT registration, while coherence-based beamforming of photoacoustic images improved target localization, which is important for tracking tool tips during pedicle hole creation. As shown in the figure, amplitude-based photoacoustic beamforming differentiated signals associated with an optical fiber place inside a pedicle hole (which is ideal for screw placement) from signals associated with an optical fiber touching cortical bone (which is characteristic of an impending bone breach that needs to be avoided). This proposed combination of imaging modalities and beamforming methods is promising to assist surgeons with identifying and avoiding accidental bone breaches during spinal fusion surgeries.
These new findings nicely complement our previous findings demonstrating that photoacoustic-based differentiation is possible prior to the creation of any holes, which is advantageous for correctly determining an appropriate starting point for hole creation. Together, these findings represent a complete system that can be used prior to and during pedicle hole creation for spinal fusion surgeries.
Citation: González E, Jain A, Bell MAL, Combined ultrasound and photoacoustic image guidance of spinal pedicle cannulation demonstrated with intact ex vivo specimens, IEEE Transactions on Biomedical Engineering (accepted December 17, 2020) [pdf]
The PULSE Lab welcomes Serene Kamal and Joshua Krachman.
Serene received the B.S. degree in Electrical Engineering from the University of California, Los Angeles. She will be matriculating as a PhD student in the ECE Department.
Prof. Bell was awarded $1M from the NSF to advance cardiac procedures with the broader goal of replacing fluoroscopy one day. The objective of this award is to apply theoretical spatial coherence models and experimental optical analyses to understand the limits of a novel, integrated robotic-photoacoustic imaging system for guiding cardiac surgeries and interventions. This work will be completed in collaboration with Jonathan Chrispin, MD at Johns Hopkins Medicine.
More details on the basic principles of the proposed approach are available in our initial journal publication on this topic:
This work has also been featured in the following articles and press releases:
We additionally have a pending patent for these ideas.
Alycen Wiacek and Kelley Kemspki were selected to receive the MICCAI Student Participation Award! The MICCAI Society provided 50 of these awards non-author student member registrations to support online participation from diverse members of the global scientific community, considering the virtual nature of the MICCAI 2020 conference this year. The award selection committee included representation from the MICCAI Student Board, the MICCAI Society Diversity Working Group, Women in MICCAI, and the MICCAI 2020 Conference Organization. This selection committee was chaired by the MICCAI awards coordinator. Congrats to Alycen and Kelley on their selection!
Prof. Bell shares her thoughts on Photoacoustic imaging for surgical guidance: Principles, applications, and outlook in an invited Perspective that was recently published in the Journal of Applied Physics. According to the journal’s website: Perspective articles are written to present an expert viewpoint on topics currently generating a lot of interest in the research community. While perspectives generally provide a brief overview of the topic, their main purpose is to provide a forward looking view on where progress in a particular research area is heading.
Citation: Bell MAL, Photoacoustic imaging for surgical guidance: Principles, applications, and outlook, Journal of Applied Physics, 128(6):060904, 2020 [pdf]
All researchers working in at least one of the following areas of Translational Photoacoustic Imaging for Disease Diagnosis, Monitoring, and Surgical Guidance are invited to submit to the Biomedical Optics Express feature issue on this topic.
Congratulations to Kelley Kempski! Her first-author journal paper entitled Application of the generalized contrast-to-noise ratio to assess photoacoustic image quality was published in Biomedical Optics Express.
This paper investigates a newly developed, probability-based, generalized contrast-to-noise (gCNR) when applied to photoacoustic images. More traditional metrics experience large variations when a target is fully detectable with additional increases bearing no impact on photoacoustic target detectability. In addition, gCNR is robust to changes in traditional metrics introduced by applying a minimum threshold to image amplitudes. Therefore, gCNR has promising potential to provide additional insight, particularly when designing new beamformers and image formation techniques and when reporting quantitative performance without an opportunity to qualitatively assess corresponding images (e.g., in text-only abstracts). We recommend gCNR as a new standard for assessment of novel photoacoustic beamforming and image formation techniques.
Citation: Kempski KM, Graham MT, Gubbi MR, Palmer T, Bell MAL, Application of the generalized contrast-to-noise ratio to assess photoacoustic image quality, Biomedical Optics Express, 11(7), 3684-3698, 2020 [pdf]
Congratulations to Eduardo González! His first-author journal paper entitled GPU implementation of photoacoustic short-lag spatial coherence imaging for improved image-guided interventions was accepted to Journal of Biomedical Optics.
This paper introduces the first known real-time implementation of short-lag spatial coherence (SLSC) beamforming for photoacoustic imaging and applies this real-time algorithm to improve signal segmentation during photoacoustic-based visual servoing with low-energy lasers. Results are promising for the use of low-energy, miniaturized lasers to perform GPU-SLSC photoacoustic-based visual servoing in the operating room with laser pulse repetition frequencies as high as 41.2 Hz.
Citation: González E, Bell MAL, GPU implementation of photoacoustic short-lag spatial coherence imaging for improved image-guided interventions, Journal of BiomedicalOptics, 25(7):077002, 2020 [pdf]
The following PULSE Lab abstracts were accepted for presentation during the 2020 IEEE International Ultrasonics Symposium (IUS) to be held on September 6-11, 2020 online (due to COVID-19).
Congrats to Alycen, Eduardo, Michelle, Kelley, and Mardava!
Prof. Bell also collaborated with colleagues on the following work that will be presented at IEEE IUS 2020:
In addition to the above presentations, Prof. Bell will give an invited lecture on the topic:
Symposium website: https://2020.ieee-ius.org
JBO webinars were created after the world switched to virtual activities. They help to keep us connected, featuring talks and discussions about some of the hottest technologies in biomedical optics. Brian Pogue, MacLean Professor of Engineering at Dartmouth and Editor in Chief of the Journal of Biomedical Optics is the host of this webinar series, with luminaries Lihong Wang and Paul Beard as the moderators for the invited session featuring Dr. Bell.
A replay of this webinar on Photoacoustic Imaging: The Next Generation includes Dr. Bell’s invited presentation on Photoacoustic imaging for Surgical and Interventional Guidance. Dr. Bell’s presentation starts at the 40 min mark (although viewing of all presentations is encouraged to gain a broader perspective of the current state of the field).
Congratulations to Michelle Graham! Her first-author journal paper entitled Simulations and human cadaver head studies to identify optimal acoustic receiver locations for minimally invasive photoacoustic-guided neurosurgery was accepted to the journal Photoacoustics.
This paper presents simulation and experimental studies performed with both an intact human skull (which was cleaned from tissue attachments) and a complete human cadaver head (with contents and surrounding tissue intact) to investigate optimal locations for ultrasound probe placement during photoacoustic-guided surgeries of the skull base. The combined simulation and experimental results newly introduce the eye as a suitable acoustic window for surgical guidance. We also demonstrate a light delivery design that is suitable for patient use. Results are generally promising toward identifying, quantifying, and overcoming major system design barriers for progression to future patient testing.
Citation: Graham MT, Huang J, Creighton FX, Bell MAL, Simulations and human cadaver head studies to identify optimal acoustic receiver locations for minimally invasive photoacoustic-guided neurosurgery, Photoacoustics, 19:100183, 2020 [pdf]
Congratulations to Michelle Graham! Her first-author journal paper entitled Photoacoustic Spatial Coherence Theory and Applications to Coherence-Based Image Contrast and Resolution was accepted to the journal IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control.
This paper presents the first known theoretical derivation for photoacoustic spatial coherence functions, demonstrating excellent agreement with experimental results, particularly in the short spatial lag region, which is represented as a percentage of the receive aperture (click on the .gif to see for yourself). The coherence functions theory can be described by relating the van Cittert Zernike theorem to photoacoustics. We achieved the associated incoherent source requirement by modeling a photoacoustic target as a collection of spatially incoherent absorbers. This theory was then used to hypothesize and test previously unexplored principles for optimizing photoacoustic short-lag spatial coherence (SLSC) images, including the influence of the incident light profile on photoacoustic spatial coherence functions and associated SLSC image contrast and resolution.
Citation: Graham MT, Bell MAL, Photoacoustic Spatial Coherence Theory and Applications to Coherence-Based Image Contrast and Resolution, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control (accepted May 26, 2020) [pdf]
Congrats to Reese Dunne! He was our summer Research Experience for Undergraduates (REU) student who conducted the first ever virtual summer research project with us. His research topic was centered on a comparison of compressional and elastic wave simulations for presurgical planning of photoacoustic guided neurosurgery, building on recently published paper from the PULSE Lab. His outstanding work earned him a second place presentation award at the 2020 Computational Sensing and Medical Robotics (CSMR) REU Final Presentations Award Ceremony. He joins a long list of PULSE Lab REU students to win this award.
Special thanks to Reese’s graduate student mentor, Michelle Graham.
Prof. Bell was invited to give a keynote presentation at the annual King’s College London School of Biomedical Engineering and Imaging Sciences (BMEIS) Postgraduate Research (PGR) Symposium. Her presentation was delivered via Microsoft Teams on the topic “Photoacoustic Imaging for Surgical and Interventional Guidance,” which included a discussion of her career path. After this presentation, she received a thoughtful appreciation award for her participation:
The PULSE Lab welcomes two students who will be working with us this summer:
These students will be working with us for 10 weeks or more on various projects in the areas of ultrasound and photoacoustic imaging. Projects will be completed remotely in light of our current ban on in-person laboratory research due to COVID-19. Welcome Reese and Zehua!
Congratulations to Arun Nair! His first-author journal paper entitled Deep learning to obtain simultaneous ultrasound image and segmentation outputs from a single input of raw channel data was accepted to IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control. The paper will appear in the journal’s special issue on Deep Learning in Medical Ultrasound – from image formation to image analysis.
This paper explores the use of deep neural network (DNNs) as alternatives to delay-and-sum beamforming. The DNNs learned information directly from raw channel data to simultaneously generate both a segmentation map for automated ultrasound tasks and a corresponding ultrasound B-mode image for interpretable supervision of the automation. Although the focus was visualization and segmentation of anechoic targets surrounded by tissue, the concept can be adapted to any specific task of interest. Overall, the DNNs successfully translated feature representations learned from simulated data to phantom and in vivo data, which is promising for this novel approach to simultaneous ultrasound image formation and segmentation.
Citation: Nair AA, Washington K, Tran T, Reiter A, Bell MAL, Deep learning to obtain simultaneous ultrasound image and segmentation outputs from a single input of raw channel data, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control (accepted May 6, 2020) [pdf]
Prof. Bell was invited to join the Editorial Board of IEEE Transactions on Medical Imaging as an Associate Editor. The list and profiles of IEEE T-UFFC Associate Editors are maintained here.
Congratulations to Alycen Wiacek! Her first-author journal paper entitled CohereNet: A Deep Learning Architecture for Ultrasound Spatial Correlation Estimation and Coherence-Based Beamforming was accepted to IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control. The paper will appear in the journal’s special issue on Deep Learning in Medical Ultrasound – from image formation to image analysis.
This paper presents details of a novel deep neural network (DNN) architecture, named CohereNet, that was trained to estimate spatial correlation functions. The DNN-estimated correlation functions were then used to create short-lag spatial coherence ultrasound images at a faster rate than a CPU approach and with more accuracy than a GPU approach. Results were generalizable across multiple phantoms, in vivo datasets, ultrasound transducers, and ultrasound system manufacturers not included during training. CohereNet has additional potential benefits in low-power DNN-based FPGA implementations of coherence-based beamforming for miniaturized ultrasound imaging systems. In addition, CohereNet has potential utility in other areas of ultrasound imaging that require fundamental cross-correlation calculations, including elastography, speckle tracking, sound speed correction, and other advanced beamforming algorithms, such as minimum variance beamforming.
Citation: A. Wiacek, E. González and M. A. L. Bell, “CohereNet: A Deep Learning Architecture for Ultrasound Spatial Correlation Estimation and Coherence-Based Beamforming,” IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, accepted March 20, 2020 [pdf]
The PULSE Lab welcomes postdoc Manish Bhatt. Manish received a PhD from Indian Institute of Science, Bangalore and a B.Tech from National Institute of Technology. Welcome Manish!
Prof. Bell was invited to speak at the Ryerson University Biomedical Physics Colloquium.
Congratulations to Alycen Wiacek! Her first-author journal paper entitled Coherence-based beamforming increases the diagnostic certainty of distinguishing fluid from solid masses in breast ultrasound exams was accepted to Ultrasound in Medicine & Biology. A major highlight of this paper is the inclusion of a task-based user study to determine the ability of coherence-based beamforming, specifically robust short-lag spatial coherence (R-SLSC) imaging, to assess breast mass content and ultimately impact clinical care.
The information from R-SLSC images reduced the uncertainty of fluid mass content from 47.5% to 15.8%, and the number of fluid-filled masses recommended for biopsy was reduced from 43.3% to 13.3%. This work is the first to investigate coherence-based beamforming in breast ultrasound to inform clinical decision making, highlighting the potential of this novel technique to improve diagnostic certainty and to reduce the number of unnecessary biopsies of of fluid-filled breast masses.
Citation: A Wiacek, E Oluyemi, K Myers, L Mulen, MAL Bell, Coherence-based beamforming increases the diagnostic certainty of distinguishing fluid from solid masses in breast ultrasound exams, Ultrasound in Medicine and Biology, accepted January 20, 2020 [pdf]
The PULSE Lab recently returned from SPIE Photonics West 2020, after enjoying multiple opportunities for exposure throughout various aspects of this grand annual event with 23,000+ attendees. First, Professor Bell was invited to give a Hot Topics presentation during the conference Plenary session. She was selected as the inaugural Journal of Biomedical Optics speaker for having the most impactful paper in 2019.
Three PULSE Lab students additionally presented aspects of their work on this hot topic.
Michelle Graham presented “Photoacoustic image guidance and robotic visual servoing to mitigate fluoroscopy during cardiac catheter interventions”
Alycen Wiacek presented “Dual-wavelength photoacoustic imaging for guidance of hysterectomy procedures”
Eduardo Gonzalez presented “A GPU approach to real-time coherence-based photoacoustic imaging and its application to photoacoustic visual servoing”
In addition to these four technical presentations, PULSE Lab members who were involved in the first known in vivo demonstration of photoacoustic image guidance for abdominal surgeries were featured in the Show Daily Weekend Edition (see pg. 3).
LaserFocusWorld Announcement (see first paragraph & “Hot Topics and Other Plenaries” section)
Congratulations to Prof. Bell for being selected to receive the inaugural IEEE UFFC Star Ambassador Lectureship Award! This award from the IEEE Ultrasonics Ferroelectrics and Frequency Control Society is intended to support early career professionals with the delivery of technical talks highlighting their research. Up to $2,500 of support is provided to create new contacts and promote new collaborations with colleagues and students at academic institutions, national laboratories and local industry.
Three PULSE Lab abstracts were accepted to SPIE Photonics West. This conference will take place February 1-6, 2019 at the The Moscone Center in San Francisco, California.
This work spans two tracks within the SPIE Photonics West BiOS Conference:
In addition to these three PULSE Lab contributions, Prof. Bell was invited to present her research during the BiOS Hot Topics Plenary Event on Saturday, February 1, 2020.
8:15 PM – 8:25 PM
Photoacoustic Imaging Assistants for Minimally Invasive Surgeries and Procedures
LaserFocusWorld Announcement (see first paragraph & “Hot Topics and Other Plenaries” section)