Transcranial eddy current damping sensors for detection and imaging of hemorrhagic stroke: feasibility in benchtop experimentation
Objective: Spontaneous intracerebral hemorrhage occurs in an estimated 10% of stroke patients, with high rates of associated mortality. Portable diagnostic technologies that can quickly and noninvasively detect hemorrhagic stroke may prevent unnecessary delay in patient care and help rapidly triage patients with ischemic versus hemorrhagic stroke. As such, the authors aimed to develop a rapid and portable eddy current damping (ECD) hemorrhagic stroke sensor for proposed in-field diagnosis of hemorrhagic stroke. Methods: A tricoil ECD sensor with microtesla-level magnetic field strengths was constructed. Sixteen gelatin brain models with identical electrical properties to live brain tissue were developed and placed within phantom skull replicas, and saline was diluted to the conductivity of blood and placed within the brain to simulate a hemorrhage. The ECD sensor was used to detect modeled hemorrhages on benchtop models. Data were saved and plotted as a filtered heatmap to represent the lesion location. The individuals performing the scanning were blinded to the bleed location, and sensors were tangentially rotated around the skull models to localize blood. Data were also used to create heatmap images using MATLAB software. Results: The sensor was portable (11.4-cm maximum diameter), compact, and cost roughly $100 to manufacture. Scanning time was 2.43 minutes, and heatmap images of the lesion were produced in near real time. The ECD sensor accurately predicted the location of a modeled hemorrhage in all (n = 16) benchtop experiments with excellent spatial resolution. Conclusions: Benchtop experiments demonstrated the proof of concept of the ECD sensor for rapid transcranial hemorrhagic stroke diagnosis. Future studies with live human participants are warranted to fully establish the feasibility findings derived from this study.
Additional Information© 2021 AANS. Submitted February 26, 2021. Accepted April 8, 2021. S.S., Y.C.T., A.W.T., N.S., and G.Z. are funded by National Institute of Neurological Disorders and Stroke (NINDS) grant no. R01 NS119596-01. Author Contributions: Conception and design: Shahrestani. Acquisition of data: Shahrestani. Analysis and interpretation of data: Shahrestani. Drafting the article: Shahrestani. Critically revising the article: Shahrestani, Strickland, Bakhsheshian, Mack, Toga, Sanossian, Tai. Reviewed submitted version of manuscript: all authors. Approved the final version of the manuscript on behalf of all authors: Zada. Statistical analysis: Shahrestani. Administrative/technical/material support: Zada, Tai. Study supervision: Zada, Tai. Disclosures: Dr. Mack reports being a consultant to Integra and having direct stock ownership in Rebound Therapeutics and Cerebrotech.