Investigative Techniques Commons^™

Beyond The Square Pulse: Waveform Shape, Eeg Correlates, And The Pursuit Of Natural Sensation In Tens, Jason Whitson

Honors Undergraduate Theses

This study investigates the relationship between electrical stimulus characteristics of shape and charge on evoked sensations and electroencephalogram (EEG) data during multi-waveform transcutaneous electrical nerve stimulation (TENS) of the median nerve. Neuromodulation methods have traditionally had little control over the location and quality of their associated evoked sensation (e.g., electric, vibration, touch). This experiment utilized five unique stimulus waveforms during TENS stimulation. EEG data were collected concurrently to provide an introductory objective measure of the neural responses underlying these sensory changes. Eleven participants completed three tasks (thresholding, super-threshold stimulation, two-alternative forced choice) using a two-electrode TENS approach. Stimulus waveforms were …

Near Real-Time Adaptive Isotropic And Anisotropic Image-To-Mesh Conversion For Cerebral Aneurysm Simulations, Kevin Garner, Chander Sadasivan, Nikos Chrisochoides

Computer Science Faculty Publications

This paper presents two performance optimization techniques for a mesh adaptation method that is designed to help streamline the discretization of complex vascular geometries within the numerical modeling process. This method is integrated into a pipeline with an image-to-mesh conversion tool to generate adaptive anisotropic meshes from segmented medical images. The pipeline is shown to satisfy quality, fidelity, smoothness, and robustness requirements while providing near real-time performance for medical image-to-mesh conversion. Tested with two brain aneurysm cases and utilizing up to 96 CPU cores within a single, multicore node on Purdue University’s Anvil supercomputer, the parallel adaptive anisotropic meshing method …

Adaptive Self-Attention For Enhanced Segmentation Of Adult Gliomas In Multi-Modal Mri, Evan P. Savaria, Jiangwen Sun

Computer Science Faculty Publications

Every year there are an estimated 80,000–90,000 new glioma cases, highlighting the need for reliable imaging-based decision support. Although deep learning has improved tumor sub-region segmentation, many state-of-the-art models fail to fully capture complementary information across T1, T1Gd, T2, and FLAIR MRI modalities and often operate as “black boxes,” limiting physician trust when precise delineation is critical for surgical planning, radiation targeting, and treatment monitoring. To address these limitations, we propose AIMS, an Adaptive Integrated Multi-Modal Segmentation framework that maintains modality-specific feature streams and employs adaptive self-attention within a hierarchical CNN-Transformer architecture to prioritize and fuse multi-modal MRI features. We …

Baseline Lymphopenia Predicts Survival In Ici-Naïve Solid Tumor Patients Receiving Immune Checkpoint Inhibitors: A Propensity-Matched Real-World Pan-Cancer Analysis, Ahmed Ismail, Nina Balanchivadze, George R. Simon, Yanis Boumber

Department of Medicine Faculty Publications

Background: Baseline lymphopenia is common among advanced solid tumors and may influence the efficacy/safety of immune checkpoint inhibitors (ICIs), but large real-world evidence is limited. We evaluated the association between baseline absolute lymphocyte count (ALC) and clinical outcomes in adults with solid tumors treated with ICIs in routine practice. Methods: We performed a retrospective cohort study using TriNetX. Adults with solid tumors who received pembrolizumab, nivolumab, or atezolizumab (ICI-Naïve) between January 2015 and June 2026 were included. Baseline ALC was measured within 30 days before first treatment and was classified as lymphopenic (ALC < 1.5 × 10⁹/L) or non-lymphopenic (ALC ≥ 1.5 × 10⁹/L). Propensity score matching (1:1) yielded 5249 patients per group. The index date was the first immunotherapy date, and outcomes were assessed at 6, 12, 24, 36 months, and 5 years. The primary outcome was 24-month overall survival (OS); secondary outcomes were OS at 6 and 12 months and 6-month risks of healthcare utilization, immune-related adverse events (irAEs), and serious infections; and exploratory outcomes included OS at 36 months and 5 years. All outcomes were analyzed using Kaplan–Meier analysis, Cox proportional hazards models, and risk ratios. Subgroup analysis included OS stratified by solid tumor subtypes and prior lines of therapy. Results: After matching, patients with baseline lymphopenia …

Microarray Analysis Of Human Abdominal Aortic Aneurysm With Emphasis On Cardiovascular Genes Revealed Differentially Expressed Genes, Song Lu, Li Ping Li, John V. White, Xiaoying Zhang, Ifeyinwa Nwaneshiudu, Adaobi Nwaneshiudu, Nectaria Ntaoula, John Gaughan, Dimitri S. Monos, Wan-Lu Lin, Charalambos C. Solomides, Emilia L. Oleszak, Chris D. Platsoucas

Biological Sciences Faculty Publications

Background/Aim: We examined gene expression profiles in abdominal aortic aneurysm (AAA) lesions vs. normal aortas by cDNA microarray and real-time quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR).

Materials and Methods: Phosphorus (32P)-labeled cDNA from AAA specimens (mean AAA size 6.65 cm) and normal aortas were hybridized with a 588-gene microarray primarily of the cardiovascular system. The results were validated by qRT-PCR.

Results: A total of 35 out of the 588 genes were differentially expressed, with either log2 ratio of AAAs/controls ≥1 (upregulated; 20 genes) or ≤−1 (downregulated; 15 genes) in AAA lesions vs. normal aorta, and 25 of these were significantly …

Preoperative Patient Sentiment Is Associated With Postoperative Outcomes In Adult Spinal Deformity Surgery, Ross J. Gore, David Mazur-Hart, Mohan K. Sunkara, Aaqib Ali, Qizar Ali, Christopher J. Lynch, Christopher Ames

Center for Secure and Intelligent Critical Systems (CSICS) Publications

Study Design: Prospective observational pilot study of adult spinal deformity surgery patients.

Objective: To determine whether preoperative patient sentiment, quantified using a 21-class valence scale extending the CARP paradigm implemented through an offline Large Language Model, predicts postoperative outcomes.

Summary of Background Data: Predicting adult spinal deformity surgery outcomes remains challenging with traditional clinical and radiographic parameters alone. Although patient psychological factors and expectations significantly influence postoperative satisfaction and quality of life, systematic approaches to capture these factors are underdeveloped. Offline Large Language Models offer scalable, privacy-preserving psychological risk stratification.

Materials and Methods: We prospectively enrolled 18 patients undergoing adult …

Brief Pulses Of High-Level Fluid Shear Stress Enhance Metastatic Potential And Rapidly Alter The Metabolism Of Cancer Cells, Amanda N. Pope, Devon L. Moose, Guy O. Hudson, Hank R. Weresh, Marion R. Dykstra, Aabha Y. Joshi, Patrick Breheny, Eric B. Taylor, Michael D. Henry

Department of Biomedical and Translational Sciences Faculty Publications

Circulating tumor cells (CTCs) face challenges to their survival, including mechanical and oxidative stresses that are different from cancer cells in solid primary and metastatic tumors. The impact of adaptations to the fluid microenvironment of the circulation on the outcome of the metastatic cascade is not well understood. Here, we find that cancer cells exposed to brief pulses of high-level fluid shear stress (FSS) exhibit enhanced invasiveness and anchorage-independent proliferation in vitro and enhanced metastatic colonization/tumor formation in vivo. Cancer cells exposed to FSS rapidly alter their metabolism in a manner that promotes survival by providing energy for cytoskeletal remodeling …

Us Drug Policy Does Not Align With Experts' Rankings Of Drug Harms: A Multi-Criteria Decision Analysis, Michael Broman, Alan K. Davis, Stacey Armstrong, Adam Levin, Kaltum Ahmed, Gustavo A. Angarita, Brooke J. Arterberry, Cecilia Bergeria, Mitch Earleywine, Kathryn S. Gex, Tom Gregoire, Jamey J. Lister, David S. Mathai, Nicky J. Mehtani, Nathan Menke, Charles D. Nichols, Hillary Shaub, Alayna P. Tackett, Brandon Weiss, Nefize Yalin, Lawrence D. Phillips

School of Medicine Faculty Publications

Background United States drug policy is primarily based on the Controlled Substances Act of 1970 and largely contradicts scientific evidence about how to mitigate drugs' harms. Expert consensus on drug harms could inform policy that improves the health of people who use drugs while reducing negative societal impacts of drug use. Therefore, this study adapted and extended the relevant 2010 United Kingdom multi-criteria decision analysis, rating drug harms by criteria comprising health and social impacts to people who use drugs and their families, communities, and society.Methods Seventeen experts on drug use in the US, including three with lived experience of …

Metastatic Uveal Melanoma Surveillance: A Delphi Panel Consensus, Juan Alban, R. Christopher Bowen, David A. Reichstein, Meredith Mckean, Jose Lutzky, Ezekiel Weis, Richard D. Carvajal, Susan Dulka, Brian G. Morse, Marcus O. Butler, Suthee Rapisuwon, Kevin B. Kim, Sanjay Chandrasekaran, Allison Betof Warner, Jonathan S. Zager, Bartosz Chmielowski, Sapna P. Patel, Leonel Fernando Hernandez-Aya, Zelia M. Correa, Leslie A. Fecher, Yana G. Najjar, Kamaneh Montazeri, Alexander N. Shoushtari, Asad Javed, Dan S. Gombos, April K. S. Salama, Katy Tsai, Frank H. Miller, Nikhil Khushalani, Rino S. Seedor, Evan J. Lipson, Sunil A. Reddy, Elizabeth Buchbinder, Shailender Bhatia, Anna Pavlick, Inderjit Mehmi, Thomas Aaberg, Alexandra P. Ikeguchi, Ivana K. Kim, Scott D. Walter, Arun D. Singh, Ryan J. Sullivan, Jacob S. Choi, Basil K. Williams, Marlana Orloff, Prithvi Mruthyunjaya, Megan D. Schollenberger, Namita Gandhi, J. William Harbour, Sunandana Chandra

Department of Radiology Faculty Papers

BACKGROUND/OBJECTIVES: Uveal melanoma is a rare but aggressive intraocular malignancy that metastasizes in up to half of patients, most commonly to the liver, despite effective local treatment. In the absence of robust evidence, there are no standardized guidelines for post-treatment surveillance, resulting in wide variation in imaging modalities, frequency, and duration across physicians and institutions. This study aimed to develop expert consensus recommendations for surveillance strategies in patients with uveal melanoma.

METHODS: A modified Delphi method was conducted across three iterative survey rounds between September 2024 and February 2025 using an online platform. Panelists included medical oncologists, ocular oncologists, radiologists, …

Concentric Macular Rings And Oct Corrugations In Foveal Hypoplasia: Proof Of Concept For An Optical Interference Mechanism, Ari August, Ralph Eagle, Tatyana Milman, Rebecca Procopio, Bruce Schnall, Jose Pulido

Wills Eye Hospital Papers

BACKGROUND: Concentric macular rings (CMR) and Henle fiber layer (HFL) corrugations, potential clinical biomarkers of foveal hypoplasia, have been observed in laser fundus photographs and optical coherence tomography (OCT) images, respectively. Some believe these findings represent true anatomical structural changes while others hypothesize that they are artifacts of interference; however, to our knowledge, no previous study has provided evidence to support either theory.

METHODS: This retrospective case series analyzed CMR and OCT corrugations in 3 patients (6 eyes) with foveal hypoplasia. Dark fringe diameters of CMR at different wavelengths (λ: red = 635, green = 532, blue = 488 nm) …

Application Of Flexible Endoscopy For Gastrointestinal Foreign Body Removal In A Leopard Gecko (Eublepharis Macularius), Jang-Hee Han, Seung Yoon Ahn, Do Na Lee, Seong Chan Yeon

The Thai Journal of Veterinary Medicine

A male captive-bred leopard gecko (Eublepharis macularius) presented with a history of inadvertent ingestion of a rubber tip from forceps during feeding. The foreign body was impalpable on physical examination, while radiographic evaluation confirmed its presence in the stomach. Considering the procedural risks associated with invasive surgical interventions, endoscopic retrieval under general anesthesia was pursued. An initial attempt using a 2.8 mm superfine flexible endoscope with 0.8 mm forceps was unsuccessful due to insufficient stability, which hindered effective navigation to the foreign body. In contrast, a second attempt using a larger 9.2 mm flexible endoscope with 2.3 mm …

Prediction Of Lung Vital Capacity Value From Thoracoabdominal Expansion In Young Adults, Aung Myo Htun, Aung Aung Nwe, Chatchaya Jaimanee, Thiwaphon Chatprem, Saowanee Nakmaroeng, Chatchai Phimphasak

Journal of Health Research

Background: Vital capacity (VC) is a fundamental indicator of pulmonary health, but its routine assessment often depends on spirometry devices that may be unavailable (i.e. because of access, cost) in many clinical or community settings. In contrast, lower costal (LC) and upper abdominal (AB) expansions are simple, equipment-free methods commonly used in physiotherapy.

Method: This cross-sectional study was aimed at developing prediction equations for VC using LC or upper AB expansion alongside demographic and anthropometric variables. The study involved 116 healthy nonsmokers (53 male and 63 female individuals) aged 18–39 years. VC was measured via spirometry using a …

A Phase-Ii Randomized Controlled Pilot And Feasibility Study Of Nicotinamide Riboside Supplementation In Older Adults With Amnestic Mild Cognitive Impairment, Christopher R. Martens, Kevin P. Decker, Theodore M. Deconne, Faria Sanjana, Fiona Horvat, Nicholas A. Rizzi, Catherine Awad, Elizabeth Habash, Joshua C. Hobson, Michael L. Armstrong, Nichole Reisdorph, Ryan T. Pohlig, Alyssa M. Lanzi, Curtis L. Johnson, Matthew L. Cohen, James M. Ellison

Department of Psychiatry and Human Behavior Faculty Papers

Abstract

Background

The decline of nicotinamide adenine dinucleotide (NAD+) with aging may elevate risk of Alzheimer’s disease and related neurocognitive disorders (ADRD) by impairing cellular energy metabolism and reducing cerebral blood flow.

Method

We conducted a 12-week double-blind, randomized, placebo-controlled pilot study to evaluate the safety, tolerability, and preliminary efficacy of the NAD+ precursor, nicotinamide riboside (NR; 500 mg b.i.d.), for enhancing cognitive function and cerebral perfusion in older adults with mild cognitive impairment (MCI).

Result

52 participants (33 females, 19 males) were randomized and 42 completed the trial (NR = 22, placebo = 20). Adherence was similar between groups …

P-15 Peptide Enhanced Bone Graft Improves Time To Fusion In Transforaminal Lumbar Interbody Fusion: A Randomized, Controlled, Investigational Device Exemption Study, James S. Harrop, Michael P. Steinmetz, John E. O'Toole, Christopher D Chaput, Rick C. Sasso, K. Brandon Strenge, Greg Maislin, Jeffrey P. Mullin, Thomas B. Freeman, Anthony Guanciale, Howard Lantner, Michael E. Janssen, David G. Schwartz, John M. Small, Wellington K. Hsu, Paul M. Arnold

Department of Neurosurgery Faculty Papers

STUDY DESIGN: Prospective, multicenter, single-blind, randomized, and controlled pivotal study.

OBJECTIVE: Compare time-to-fusion in patients treated with P-15L (PearlMatrix TM P-15 peptide enhanced bone graft) versus local autograft over 24 months and evaluate changes in pain and quality of life at 24 months relative to baseline.

SUMMARY OF BACKGROUND DATA: P-15L, an FDA-designated breakthrough device, is a composite bone graft with P-15, a 15-amino acid polypeptide that promotes cellular adhesion, proliferation, and differentiation to support bone formation.

METHODS: Patients (22-80 y) with degenerative disc disease were randomized to the investigational (P-15L) or control (local autograft) group during single-level transforaminal lumbar …

Genomic Ascertainment Of Chek2 -Related Cancer Predisposition, Sunyoung Kim, Jung Kim, Mark Ramos, Jeremy Haley, Diane Smelser, H. Shanker Rao, Uyenlinh L. Mirshahi, Katherine L. Nathanson, Barry I. Graubard, Hormuzd A. Katki, David Carey, Douglas R. Stewart

School of Graduate Studies Faculty Publications

Importance: There is clear evidence that deleterious germline variants in CHEK2 increase risk for breast and prostate cancers; there is limited or conflicting evidence for other cancers. Objective: To quantify the prevalence of as well as cancer risk and survival associated with CHEK2 germline pathogenic and likely pathogenic variants using genomic ascertainment. Design, Setting, and Participants: This case-control study used 2 electronic health record-linked and exome-sequenced biobanks: UK Biobank (n = 469765) and Geisinger MyCode (adults only; n = 167050). Variants were classified according to American College of Medical Genetics and Genomics and the Association for Molecular Pathology criteria. Cases …

Radiogenomic Profiling Of Prostate Tumors Prior To External Beam Radiotherapy Converges On A Transcriptomic Signature Of Tgf-Β Activity Driving Tumor Recurrence, Anson T. Ku, Uma Shankavaram, Shana Y. Trostel, Hong Zhang, Sumeyra Kartal, Houssein A. Sater, Stephanie A. Harmon, Nicole V. Carrabba, Yang Liu, Hyunnam Ryu, James A. Proudfoot, Boon Hao Hong, Bradford J. Wood, Peter A. Pinto, Peter L. Choyke, Mack Roach, Howard M. Sandler, Stephanie L. Pugh, Kenneth L. Zeitzer, Lucas C. Mendez, Nirav S. Kapadia, William A. Hall, Anand B. Desai, Radka S. Stoyanova, Alan Pollack, Elai Davicioni, Melvin L. K. Chua, Baris Turkbey, Adam G. Sowalsky, Deborah E. Citrin

Einstein Health Papers

PURPOSE: Clinical risk grouping based on PSA, tumor grade, and disease extent guides treatment intensity for localized prostate cancer. However, many patients with intermediate- or high-risk disease treated with external beam radiotherapy (EBRT) and androgen deprivation therapy (ADT) still develop biochemical recurrence (BCR). Early identification of patients at high risk for BCR could enable personalized treatment strategies.

EXPERIMENTAL DESIGN: We prospectively enrolled 29 patients with intermediate- or high-risk prostate cancer undergoing EBRT and ADT. Pretreatment biopsies (n = 60) underwent whole-transcriptome microarray and whole-exome sequencing. Patients received multiparametric MRI at baseline and 6 months after treatment, with a median follow-up …

Pediatric Anesthesia And Virtual Reality: Managing Perioperative Pain And Anxiety– A Scoping Review, Moneer Sharafi, Mason Pham, Alec Wiscombe

Doctoral Projects

Pediatric surgery is common, but it often causes considerable anxiety and pain. A staggering percentage of children experience preoperative anxiety, which can heighten pain, delay recovery, and contribute to complications such as emergence delirium and longer-term behavioral issues (Fortier & Kain, 2015). Virtual reality (VR), which immerses users in computer-generated environments, has been proposed as a distraction technique to reduce these challenges. This Doctor of Nursing Practice (DNP) project conducted a scoping review to examine the effectiveness of VR in reducing perioperative pain and anxiety in pediatric patients. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses …

Electrochemical Sensors For In Situ Monitoring Of Reactive Species During Cold Atmospheric Plasma-Based Therapies, Jonathan Thomas, Suneel Kumar, Gagana Karkada, Julia Sutter, Kristina Pattison, Jason Rainone, Dhruv Patel, Shashank Madhavan, Fred Krebs, Francois Berthiaume, Vandana Miller, Katharina Stapelmann

Kimmel Cancer Center Faculty Papers

Cold atmospheric pressure plasma (CAP) is emerging as a clinically relevant therapy for dermatological conditions such as actinic keratosis, warts, and chronic wounds. However, these therapies lack strategies to monitor CAP delivery in situ and to ensure delivery of an effective CAP dose without unwanted toxicity. CAP acts as a therapeutic agent in these biomedical applications primarily (but not solely) through reactive oxygen and nitrogen species (RONS) generated at transiently high local concentrations. Here we demonstrate the use of bio-electrochemical sensors capable of real-time measurements of key CAP RONS: hydrogen peroxide and oxidation-reduction-potential (ORP). In in vitro scratch assays and …

Model For Calculating Impact Force For Individualized Hip Fracture Prediction During A Fall, Alisha Agarwal, Daniel Kargilis, Nishtha Gupta, Michael Chang, Rui Feng, Gregory Chang, Chamith S. Rajapakse

Student Papers, Posters & Projects

Osteoporotic-related weakening of bone is a common cause of hip fractures. The standard of care for the diagnosis and management of osteoporosis is the dual-energy x-ray absorptiometry bone mineral density T-scores. Many individuals considered nonosteoporotic, however, still sustain fractures since these tools do not incorporate vital bone parameters and subject-specific characteristics. The purpose of this work was to (1) develop a simple analytical model for estimating the force exerted on the femur during a fall (i.e., impact force) based on measurable patient metrics and (2) define a quantifiable fracture risk index by comparing finite-element-derived bone strength and impact force, which …

First Mammography Screening Participation And Breast Cancer Incidence And Mortality, Forruk Ahmed, Anna Aleksyeyeva, Oman Balan, Ashley Hassang

Publications and Research

This population-based cohort study evaluated the long-term relationship between initial participation in mammography screening and subsequent breast cancer outcomes among approximately 432,000 women in Stockholm, Sweden. Women were invited to their first screening between 1991 and 2020 at ages 40 or 50 and followed for up to 25 years through national health registries. Overall, 32% did not attend their initial screening. Non-attenders were significantly less likely to participate in later screening rounds and were more likely to be diagnosed with advanced disease, showing 1.5-fold higher odds of stage III and more than 3.5-fold higher odds of stage IV breast cancer …