Siyar Bahadir, MD, PhD(c)

Neurosurgeon · Physician-Scientist · Clinical AI · Global Health

I am a neurosurgeon, physician-scientist and software builder working across clinical AI, bioelectronic medicine, connectomics and surgical technology. My clinical background includes two years as a rural emergency physician and regional EMS coordinator in a resource-constrained region; six years of neurosurgical residency at a high-volume academic center, including two years as chief resident and more than 450 operations across major neurosurgical subspecialties; and subsequent independent rural neurosurgical practice in Turkey.

Over the last several years, I have used AI to analyze clinical and scientific problems and turn them into practical tools and workflows that other people can use. That work now spans clinical AI, experimental science, treatment planning, connectomics and surgical technology, increasingly through global teams working across institutions and specialties. My work has also brought me into broader global health and science communities, including the 2025 Brain Economy Summit during the UN General Assembly.

2 years rural emergency medicine & EMS coordination6 years neurosurgery residency · 2 as chief resident450+ neurosurgical operations2 provisional patent applications
Selected work

Clinical problems turned into usable systems

Tools, papers, datasets, talks and visual work collected with the projects that produced them.

AI extending me as a clinician

During neurosurgical residency I was already building computer-vision models for intracranial hemorrhage on CT. By late 2022, early language models began extending what I could do in clinical research without a dedicated computational team.

One project grew into a reusable quantitative pipeline that offered a new way to examine normal-pressure hydrocephalus. It remains in use as new patients enter the study in Turkey, and global collaborators independently extended both the dataset and the method into new Hydrocephalus Society work, including an award-winning project.

Cistern — 3D anatomy & flow simulation

My neurosurgery thesis on normal-pressure hydrocephalus (NPH) developed quantitative MRI analysis of the brain and its cerebrospinal-fluid spaces. That work provided the anatomical foundation for Cistern, an interactive 3D modeling and simulation project. International collaborators subsequently extended the NPH methods and dataset into Hydrocephalus Congress presentations, including an award-winning project.

I built the browser application to bring ventricular and cisternal geometry, anatomical sections and an exploratory CSF-flow model into one workspace. The later simulation extension uses a lattice-Boltzmann fluid solver and advection–diffusion tracers, with configurable catheter inlets, outlets and drainage. Users can change an experiment and inspect tracer arrival and retention across compartments.

This is a research demonstration for exploring model behavior, rather than a validated prediction of an individual patient’s CSF physiology.

Cistern application showing colored 3D fluid compartments, anatomical sections and structure controls
Saved application view: thesis-derived fluid-space anatomy, 3D structures and anatomical sections.
3D modeling · scientific computing · interactive simulation

Ultrasound — learning from sparse annotations

With Netanel Ben-Shalom at Lenox Hill Hospital, whose work includes transcranioplasty ultrasound through sonolucent implants, I built a rapid ultrasound annotation and segmentation tool. It trains random forests from sparse annotations, designed around the limited input a clinician could realistically provide in the operating room.

My contribution was hands-on implementation: turning the annotation workflow and machine-learning approach into a usable research tool. The manuscript has been submitted, and a medRxiv preprint is planned. I also contribute to the group’s broader transcranioplasty-ultrasound research.

Image analysis · random forests · clinician-facing software

Manuscript submitted · Preprint planned

MRI–Ultrasound Explorer

I built an interactive imaging workspace that brings registered MRI and intraoperative ultrasound into a shared 3D scene, alongside reference white-matter pathways and cortical regions. Linked views let researchers inspect the ultrasound window in its wider anatomical context.

The example below combines RESECT MRI/ultrasound with mapped population-reference tractography and HCP-MMP cortical regions. The pathways and regions provide anatomical context; they are not structures directly measured by ultrasound.

Registration · tractography · anatomical visualization · web engineering

Interactive research demo available on request.

Data: RESECT (CC BY 4.0); Yeh population tractography atlas (CC BY-SA 4.0); HCP-MMP cortical regions under WU-Minn HCP data-use terms. Figures include registration, reslicing and visualization adaptations; shared under CC BY-SA 4.0 where applicable.

Clinical AI — evaluating capability and limits

In 2024, I co-authored a Clinical Neurology and Neurosurgery study evaluating ChatGPT on brain-tumor diagnosis and treatment planning. I built the API-based system that sent clinical questions to the model and captured its answers for independent assessment by practicing neurosurgeons.

With Randy D’Amico, I later moved from benchmarking performance to a harder question: what happens when AI becomes part of the clinical cognitive system? That became our 2026 Neurosurgery letter on the extended mind and the uneven frontier of clinical AI.

It also led to an invited Neurosurgery review on how AI studies should handle data quality, leakage, validation, interpretability, reproducibility and clinical meaning.

BrachyAtlas — specialist planning as an AI-integrated workflow

With A. Gabriella Wernicke and Netanel Ben-Shalom, I built BrachyAtlas to combine anatomy, imaging, implant geometry and radiation dose in one patient-specific intracranial brachytherapy workflow.

It integrates those inputs with an AI agent that helps the clinician work through voluminous connectomic and expected radiation-damage reports, surfacing the anatomy, likely network effects and treatment tradeoffs that matter most for planning.

Live system

Building new experimental science with AI

During my PhD at the Feinstein Institutes, working with Stavros Zanos and Eric H. Chang, I built a human peripheral-nerve imaging platform with AI as part of the process. Over three years, it grew to span tissue clearing, light-sheet microscopy, molecular anatomy, image analysis and single-fiber reconstruction.

AI also helped overcome physical constraints: I designed and iterated custom holders, access tools and medical-device concepts, then 3D-printed and tested them experimentally. Some concepts became the basis for provisional patent work—bridging ideas, code and physical tools.

The work led to invited presentations at Rockefeller University and the Center for Pain Studies at UT Dallas.

From the same program came the human vagus atlas: we turned thousands of anatomical branch observations into a standardized, surgically relevant map, a Brain Stimulation paper, open data and analysis, and an interactive explorer. NIH SPARC invited a dedicated seminar; Kevin Tracey called it “a major advance in the field of vagus nerve science,” noting the question had persisted “ever since the time of Galen.”

AI as a force multiplier for other teams

With Randy D’Amico’s brain-tumor group, I build systems that turn dense patient-specific connectomic data into interpretable phenotypes and longitudinal trajectories.

The Disconnectome Explorer is the quickest to try: place a tumor in a 3D brain and it returns the tracts it would disrupt. What began as analysis code has grown into tools the team can use directly—small analytical capabilities that can be called, combined and reused through increasingly agent-integrated workflows.

Live tools & current work

Neuroplastic surgery — reusable clinical tools

With Netanel Ben-Shalom, we converted visual cranial-deformity judgment into an automated 3D quantitative step. The work was presented orally at CNS and is accepted in Operative Neurosurgery.

The collaboration led to my involvement with the Society for Neuroplastic Surgery and tools its members can use. I built Neuroplastic Anatomy for publication-quality, reusable AI anatomy illustrations; outputs are entering Society educational supplements. I am a member of the Society for Neuroplastic Surgery and presented my quantitative cranial-shape measurement work at its event at Lenox Hill Hospital in New York. Our ongoing collaboration also includes Ben-Shalom’s transcranioplasty-ultrasound research through sonolucent implants.

Paper, presentation & tool
Experience & credentials

Clinical, scientific and technical background

Training and roles behind the work above.

Experience

The Feinstein Institutes for Medical Research / Elmezzi Graduate School

Elmezzi Scholar · PhD Candidate, Bioelectronic Medicine | 2023–present · Manhasset, NY

Human translational neuroscience focused on the vagus nerve and peripheral nervous system, integrating human anatomy, microscopy, molecular biology, computational imaging, software and device development.

Anamur State Hospital, Turkish Ministry of Health

Attending Neurosurgeon | 2023 · Mersin, Turkey

Independent emergency neurosurgical, trauma and acute neurological care in a resource-conscious public hospital.

Hacettepe University Faculty of Medicine

Neurosurgery Resident · Chief Resident | 2017–2023 · Ankara, Turkey

Comprehensive neurosurgical training with 450+ operations across cranial, tumor, vascular, trauma, spinal and functional neurosurgery.

Turkish Ministry of Health — Korkut District Hospital

Rural Emergency Physician · Regional EMS Coordinator | 2015–2017 · Turkey

Frontline emergency care, triage, resuscitation, interhospital transfer and regional EMS coordination across an underserved rural region.

CerebroMap

Founder | 2022–2025

Computational brain mapping, tractography, automated MRI analysis, 3D visualization and cloud-based neuroimaging workflows.

Selected publications & work in press
Additional papers, posters, abstracts & talks
2026The Sixth Bioelectronic Medicine Summit: Neurotechnologies for Individuals and Communities. Bioelectronic Medicine.Paper ↗
2025Augmented reality in cranial surgery: head-mounted fiber tractography for brain tumor surgery.Paper ↗
2023Virtual neurosurgery anatomy laboratory: collaborative remote education in the metaverse.Paper ↗
2022Traumatic subgaleal hematoma in Ehlers-Danlos syndrome.Paper ↗
2021Group-level ranking-based hubness analysis of the human brain connectome.Paper ↗
2020Emergency diagnosis and triage with artificial intelligence in intracranial hemorrhage.Paper ↗
2025Scalable 3D cytoarchitecture models from cleared intact human ganglia and peripheral nerve.Abstract ↗
2025Minimally invasive access routes to the human nodose ganglion.Poster ↗
2025Automated 3D Measurement and Topographic Representation for Cranioplasty. CNS oral presentation.Abstract ↗
2024Single-fiber tracking and 3D reconstruction of human vagus nerve trajectories. Minnesota Neuromodulation Symposium.Record ↗
2024Fascicular Organization and Fiber Composition of the Human Vagus Nerve at Levels of Branch Emergence.Abstract ↗
2022Volumetric Analysis of the Brain in Normal Pressure Hydrocephalus.Congress PDF ↗
2026NIH SPARC invited seminar: human vagus nerve atlas.Video ↗
2026Rockefeller University Light Sheet Microscopy Workshop. Invited presentation.
2026Center for Pain Studies, UT Dallas. Invited presentation.
2026Neuroplastic & Reconstructive Surgery Symposium, Lenox Hill Hospital. Invited presentation on quantitative cranial-shape measurement.
Contact

Clinical judgment, hands-on building, and making new capabilities useful in practice.

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