Sigma-M Ventricular Pressure-Volume Analysis System for Hemodynamic Research

Overview

The Sigma-M Ventricular Pressure-Volume Analysis System is a modular, high-fidelity hemodynamic research platform engineered for real-time, in vivo assessment of cardiac function in preclinical animal models. Built upon a next-generation signal conditioning architecture leveraging surface-mount device (SMD) electronics and digital filtering, the Sigma-M enables simultaneous, synchronized acquisition of intraventricular pressure and conductance-based volume signals—delivering physiologically accurate pressure-volume (PV) loops with minimal drift and high reproducibility. Unlike conventional solid-state pressure catheters, the system integrates CD Leycom’s proprietary full-bridge silicon microchip transducers, which provide superior thermal stability, reduced zero-drift over extended recording durations, and enhanced signal-to-noise ratio. The Sigma-M serves as a direct evolutionary successor to the widely adopted Sigma-5DF platform, maintaining full backward compatibility with legacy Sigma-5DF and CFL-512 datasets—ensuring continuity in longitudinal studies and eliminating data bias introduced by platform migration.

Key Features

• Modular hardware architecture supporting up to eight expandable functional modules (e.g., V/P, ECG, auxiliary analog inputs)
• Real-time PV loop computation with user-defined time-scaling independent of sampling rate
• 16-bit A/D conversion at programmable sampling rates from 250 to 2000 Hz per channel
• Integrated ECG channel for beat-to-beat synchronization and arrhythmia detection
• Software-controlled hardware calibration—eliminating manual potentiometer adjustments and reducing operator-dependent variability
• Full-bridge solid-state pressure sensors with <1.5% full-scale drift over 60 minutes (per ISO 80601-2-27 compliant validation)
• Reusable conductance catheters rated for up to 80 animal experiments (validated per ASTM F2069-22 biocompatibility guidelines)
• 16-channel analog output option for integration with third-party DAQ systems or physiological monitors
• UL94-V0-rated ABS enclosure for electromagnetic compatibility and laboratory safety compliance

Sample Compatibility & Compliance

The Sigma-M supports a broad range of preclinical species—from murine (1.9F catheters) to bovine models—with interchangeable catheter configurations including dual-sensor 4F/7F pressure-volume catheters (with or without lumen), single-pressure 6F catheters (lumen-equipped for angiographic co-registration), and custom-length variants (6–12 mm electrode spacing). All catheters comply with ISO 10993-1 for biological evaluation of medical devices and meet FDA-recommended labeling requirements for investigational use only (IUO) in non-clinical cardiovascular research. The system architecture adheres to GLP-aligned data integrity principles: audit-trail-enabled software (Conduct-NT v5.3+), electronic signatures, and 21 CFR Part 11–compatible metadata logging—including timestamps, operator ID, calibration history, and sensor serial traceability.

Software & Data Management

Conduct-NT software provides an integrated environment for acquisition, real-time visualization, offline analysis, and regulatory-grade reporting. Key capabilities include automatic PV loop segmentation (end-diastolic, end-systolic, isovolumic phases), derivation of load-independent indices (e.g., end-systolic elastance E_es, preload recruitable stroke work PRSW), and export of time-series data in comma-separated value (.csv) format with user-definable column indexing (up to 60 parameters per beat). Raw data files retain native binary fidelity and support post-hoc reprocessing using updated algorithms without loss of resolution. Conduct-NT includes built-in tools for artifact rejection, baseline correction, and parallel processing of multi-animal cohorts—enabling batch analysis workflows aligned with FAIR (Findable, Accessible, Interoperable, Reusable) data principles.

Applications

• Preclinical evaluation of novel inotropes, lusitropes, and heart failure therapeutics
• Mechanistic studies of myocardial remodeling in hypertension, infarction, and genetic cardiomyopathies
• Validation of computational cardiac models against empirical PV dynamics
• Assessment of device effects (e.g., LVADs, valvular prostheses) on ventricular energetics and coupling efficiency
• Teaching and standardization of advanced hemodynamic metrics in graduate physiology laboratories
• Regulatory submission support for IND-enabling toxicology and pharmacodynamics studies

FAQ

Is the Sigma-M compatible with existing Sigma-5DF catheters and datasets?
Yes—the Sigma-M maintains full binary and metadata compatibility with all Sigma-5DF and CFL-512 acquisitions, enabling seamless retrospective analysis and cross-platform validation.
What catheter sizes are supported for mouse versus large-animal studies?
The system supports 1.9F catheters for murine models, 4F/6F/7F configurations for rat, rabbit, and porcine studies, and 7F/8F variants with extended electrode spacing for ovine and bovine applications.
Does Conduct-NT support automated calculation of derived hemodynamic indices?
Yes—software modules compute E_es, PRSW, arterial elastance E_a, ventriculo-arterial coupling ratio (E_es/E_a), and diastolic stiffness constants directly from raw PV data.
How is data integrity ensured during long-duration recordings?
All acquired data streams are timestamped with microsecond precision, logged with cryptographic hash verification, and stored with immutable audit trails—meeting ALCOA+ (Attributable, Legible, Contemporaneous, Original, Accurate, Complete, Consistent, Enduring, Available) standards.
Can the Sigma-M be integrated into a larger electrophysiology or imaging setup?
Yes—via UTP Ethernet interface and programmable analog outputs, the system synchronizes with optical mapping systems, MRI-compatible amplifiers, and high-speed video acquisition platforms using TTL or NIM trigger protocols.