FREEnet: a dynamic deep-learning model for freehand diffuse optical tomography

Published: Jan. 1, 2024

A deep-learning (DL) model for handheld diffuse optical tomography is presented. The fully convolutional network can reconstruct 3D absorption and scattering from arbitrarily undersampled scan data at a rate of 18.5Hz, enabling real-time imaging.

Language: Английский

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Scalable Free-Space Photonic Antennas in Foundry SOI Silicon Photonic Platforms

Optics Express, Journal Year: 2024, Volume and Issue: 32(19), P. 32782 - 32782

Published: July 8, 2024

We present a flexible, scalable, and low-noise design scheme for coupling free-space light into silicon-on-insulator (SOI) electronic-photonic integrated circuit. The proposed utilizes arrays of grating couplers with compact, inverse-designed power combining networks to couple distributed optical collection area single output waveguide, forming photonic antenna. Fabrication density compliance is maintained regardless the antenna size, can be scaled while maintaining fixed noise floor. Using experimental array antennas fabricated in GF45CLO platform, we demonstrate up 6.7× increase signal-to-noise ratio (SNR) lens-less monolithic receiver using 4×4 array.

Language: Английский

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Deep learning-enabled high-speed, multi-parameter diffuse optical tomography

Journal of Biomedical Optics, Journal Year: 2024, Volume and Issue: 29(07)

Published: July 19, 2024

SignificanceFrequency-domain diffuse optical tomography (FD-DOT) could enhance clinical breast tumor characterization. However, conventional (DOT) image reconstruction algorithms require case-by-case expert tuning and are too computationally intensive to provide feedback during a scan. Deep learning (DL) front-load computational costs, enabling high-speed, high-fidelity FD-DOT.AimWe aim demonstrate simultaneous of three-dimensional absorption reduced scattering coefficients using DL-FD-DOT, with view toward real-time imaging handheld probe.ApproachA DL model was trained solve the DOT inverse problem realistically simulated FD-DOT dataset emulating probe for human tested both synthetic experimental data.ResultsOver test set 300 tissue phantoms reconstructions, DL-DOT root mean square error by 12%±40% 23%±40%, increased spatial similarity 17%±17% 9%±15%, anomaly contrast accuracy 9%±9% (μa), crosstalk 5%±18% 7%±11%, respectively, compared model-based tomography. The average time from 3.8 min 0.02 s single reconstruction. successfully verified two tumor-emulating phantoms.ConclusionsThere is potential functional FD-DOT.

Language: Английский

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Cerebral Autoregulation Assessment through Near-Infrared Spectroscopy and Arterial Monitoring: Advancements and Clinical Implications

New Trends in Medicine Sciences, Journal Year: 2024, Volume and Issue: 5(Supplemental Issue), P. 115 - 119

Published: July 28, 2024

Cerebral autoregulation, maintaining stable cerebral blood flow across varying arterial pressures, is vital in-patient care during surgery. Traditional views suggest a mean pressure range of 50-150 mm Hg for effective autoregulation. However, patient-specific variations in autoregulatory patterns, particularly cases impaired call personalized hemodynamic and management surgical procedures. In the evaluation NIRS serves as beneficial monitoring tool. The oximetry index, correlating oxygen saturation with perfusion pressure, aids determining autoregulation limits. literature shows impacts vasoactive drugs on patients different responses, emphasizing need individualized care. summary, crucial adjusting targets based data could improve prevention hyper/hypoperfusion. This approach, moving away from generalized strategy, advocates more customized, physiology-based patient management.

Language: Английский

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Electroconvulsive therapy generates a hidden wave after seizure

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 1, 2024

Abstract Electroconvulsive therapy (ECT) is a fast-acting, highly effective, and safe treatment for medication-resistant depression. Historically, the clinical benefits of ECT have been attributed to generating controlled seizure; however, underlying neurobiology understudied remains largely unresolved. Using optical neuroimaging probe neural activity hemodynamics in mouse model ECT, we demonstrated that second brain event follows seizure: cortical spreading depolarization (CSD). We further found stimulation pulse parameters electrode configuration directly shaped wave dynamics seizure subsequent CSD. To translate these findings human patients, tested presence hemodynamic signatures post-ictal CSD using non-invasive diffuse monitoring cerebral blood flow oxygenation during routine treatments. evidence humans generate hyperemic waves after which are consistent with These results challenge long-held assumption primary outcome point new opportunities optimizing precisely modulate outcomes.

Language: Английский

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Maximizing the Reliability and Precision of Measures of Prefrontal Cortical Oxygenation Using Frequency-Domain Near-Infrared Spectroscopy

Sensors, Journal Year: 2024, Volume and Issue: 24(8), P. 2630 - 2630

Published: April 20, 2024

Frequency-domain near-infrared spectroscopy (FD-NIRS) has been used for non-invasive assessment of cortical oxygenation since the late 1990s. However, there is limited research demonstrating clinical validity and general reproducibility. To address this limitation, recording duration adequate within- between-day reproducibility prefrontal was evaluated. assess validity, a reverse analysis 10-min-long measurements (n = 52) at different durations (1–10-min) quantified via coefficients variation Bland–Altman plots. within-subject reproducibility, participants 15) completed 2-min twice day (morning/afternoon) five consecutive days. While 1-min recordings demonstrated sufficient oxygen saturation (StO2) total hemoglobin concentration (THb), ≥4 min revealed greater utility oxy- (HbO) deoxyhemoglobin (HHb) concentration. Females had lower StO2, THb, HbO, HHb values than males, but variability approximately equal between sexes. Intraclass correlation ranged from 0.50–0.96. The minimal detectable change StO2 1.15% (95% CI: 0.336–1.96%) 3.12 µM THb 0.915–5.33 µM) females 2.75% (95%CI: 0.807–4.70%) 5.51 1.62–9.42 in males. Overall, FD-NIRS good levels reliability. These findings support application field-based settings indicate 1 allows valid measures; however, data are recommended when feasible.

Language: Английский

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A 0.57 mm² Platform with 70.7% Efficient 4 mA 3.2 V Charge Pump and a Current-Input Ramp ADC for Implantable Optical Sensing of Tumors

2022 IEEE Biomedical Circuits and Systems Conference (BioCAS), Journal Year: 2023, Volume and Issue: unknown, P. 1 - 5

Published: Oct. 19, 2023

Continuous and real-time in vivo monitoring of solid tumors using implanted sensors would be transformative for precision health cancer research treatment. Optical techniques such as spectroscopy offer a path towards realizing treatments, but require additional miniaturization efforts. To address this need, we have designed prototyped an integrated circuit (IC) implantable in-vivo optical sensing tumors. Our prototype, fabricated 65nm CMOS technology, occupies 0.57mm ² active area comprises high-efficiency cross-coupled charge pump two current-input ramp analog-to-digital converters (ADCs). The pump, with peak efficiency 70.7%, delivers 12.8 mW to power the off-chip light sources necessary spectroscopy. We validate our approach through measurements on tissue simulating phantom demonstrate prototypes suitability sensing.

Language: Английский

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