Welcome to the SALAR-Bio-Lab, the central hub for an integrated cardiac electrophysiology research ecosystem. This project is the culmination of 2–3 years of intensive R&D conducted within the Golestan Ischemic Disorder Lab.
The name SALAR stands for Smart and Low-cost Advanced Analysis and Research—an acronym that, while perfectly describing the project's mission to provide accessible high-end research tools, also happens to be my first name. The SALAR-Bio-Lab (Smart and Low-cost Advanced Analysis and Research) is the product of over two years of intensive R&D at the Golestan Ischemic Disorder Lab. It represents an end-to-end open-access framework for extracting complex heart characteristics, ranging from real-time electrical time-domain markers to spatial conduction velocity vectors.
The SALAR-Bio-Lab provides a complete, transparent alternative to expensive "black-box" commercial systems. It offers a comprehensive Software Architecture Map that bridges the gap between precision hardware actuation and sophisticated bio-signal analysis. The ecosystem is designed to handle everything from micro-level electrical pacing to macro-level spatial wave visualization.
The lab is divided into two primary technical pillars, coordinated through a central computer interface:
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SALAR-Bio-DAQ: A system for high-speed data acquisition and on-line time-domain signal processing. It utilizes the SDC-1721 hardware for isolated stimulation and precise bio-signal sensing.
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SALAR-Optical-Mapping: A tempo-spatial image processing suite designed to extract electrical characteristics of the heart from mass image data. This includes specialized workflows for spectrum-specific responses like Fura-2 or RH237.
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Smart Hardware Integration: The system features a custom-built synchronous LED driver and high-speed camera interface to ensure perfect alignment between excitation light and data capture.
The project integrates three distinct software layers with custom-engineered hardware to provide a holistic view of cardiac function:
This pillar handles the "electrical" side of the lab, managing real-time data acquisition and programmed stimulation.
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Hardware Interface (SDC-1721): A custom stimulator-isolator system featuring an ATMEGA32 pulse generator, 512KB SRAM for protocol storage, and a dual-battery power management system for month-long stability.
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On-Line Processing: Utilizing the Advantech DAQ-Navi SDK, the software performs real-time scaling, FIR low-pass filtering, and instantaneous calculation of APD80, rise/fall times, and restitution curves.
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Synchronous Pacing: The system maintains strict synchronization between the DAQ and the Signal Generator, allowing for dynamic protocol adjustments (WBCL, S1-S2) on a captured heart.
This pillar handles the "visual" side, processing mass image data to visualize electrical waves across the heart surface.
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Image Processing Flow: The software ingests mass input images, performs spectrum-specific intensification (optimized for Fura-2 or RH237 dyes), and crops the ROI for analysis.
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Super-Pixel Analysis: To maintain high signal-to-noise ratios, the system extracts "super-pixel" amplitudes and applies moving average filters to each.
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Vector Mapping: Post-processing calculates conduction velocity vectors (amplitude and direction) and conduction delays, displayed across a simultaneous 32x32 grid of charts and images.
A critical hardware component that links the two pillars.
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Precision Actuation: Using an ATXMEGUA4U microcontroller and AD558 DACs, the driver controls high-power MOSFETs to pulse excitation light sources in perfect sync with the high-speed camera.
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Closed-Loop Feedback: Includes current sensing to ensure stable illumination intensity across long-duration optical mapping sessions.
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System Overview: SALAR-Bio-DAQ: Overview & Signal Logic
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Hardware Setup: SDC-1721: Power & Connection Guide
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Optical Analysis: Optical Mapping: Spatial Image Processing
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Validation: Cross-Validation with ADInstruments LabChart
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SALAR-Bio-DAQ: The source code for online/offline signal processing and stimulator control.
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SALAR-Optical-Mapping: The source code for image processing and the synchronous LED driver logic.
For a researcher or engineer, the value of SALAR-Bio-Lab lies in its Pure Time-Domain philosophy. Unlike systems that rely on frequency-domain transformations (FFT), this suite treats cardiac signals as raw, instantaneous temporal events. This allows for zero-dependency on signal history, ensuring that every marker—from an APD80 in a single MAP trace to a conduction vector on a 32x32 mapping grid—is calculated with maximum temporal fidelity.
The SALAR ecosystem is a first-principles implementation designed to make high-end electrophysiology research more accessible by bridging custom hardware with sophisticated Delphi-based analysis. I am open to professional dialogue regarding:
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Academic Cooperation: Assisting research labs in implementing or adapting these time-domain algorithms for specific cardiac studies, such as real-time APD80 detection or super-pixel extraction.
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Technical Consulting: Deep-dive discussions on the mathematics behind conduction velocity mapping (both amplitude and direction) and effective signal processing in low-SNR optical environments.
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System Design: Inquiries regarding the hardware-software synchronization of optical acquisition with external stimulators and DAQ systems through custom serial protocols.
If you are a researcher or engineer interested in collaborating, debating the merits of time-domain vs. frequency-domain processing, or implementing this technology in your facility, please feel free to reach out.
📧 Email: salarbasiri.smart@gmail.com