LX7-S Polygraph System – Advanced Instrumentation for UK Polygraph Professionals

The LX7-S Polygraph System represents the latest generation of computerised polygraph instrumentation, engineered to meet the needs of professional examiners, trainers, and researchers in psychophysiological detection of deception (PDD). Building on the heritage of Lafayette’s LX series, the LX7-S delivers precise, high-resolution physiological data in a modular, examiner-friendly format.

With its advanced sensor technology, robust construction, and forward-looking design, the LX7-S is suited to diverse testing environments—from UK police vetting units and corporate security teams to private practice and academic research.

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Advanced Physiological Monitoring

Enhanced Photoelectric Plethysmograph (PPG) Sensitivity

The LX7-S incorporates an upgraded photoelectric plethysmograph sensor capable of detecting subtle, rapid variations in blood volume. For UK examiners, this improvement is particularly valuable when working with subjects who naturally exhibit low-amplitude cardiovascular signals, enabling more consistent and reliable chart data.

Streamlined Electrodermal Activity (EDA) Acquisition

With a wider galvanic skin response range and a constant 3.59 μA current, the EDA channel produces clearer, more stable recordings. This consistency is especially beneficial in multi-subject environments, where skin resistance can vary widely due to climate, age, or ethnicity.

New ECG Channel for Pulse Arrival Time (PAT)

A notable advancement is the addition of an ECG channel for Pulse Arrival Time measurement—calculating the interval between the heart’s electrical activity (ECG) and the peripheral pulse detected by the PPG. This metric is directly correlated with blood pressure and has been shown to be as discriminative as traditional cardiograph readings in deception detection.

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Ergonomic Hardware & Modular Design

Modern Enclosure with Improved Cable Management

The LX7-S is housed in a curved ABS/polycarbonate enclosure, improving workspace organisation for UK examiners working in both controlled offices and mobile setups. This ergonomic layout reduces clutter and speeds test preparation.

Medical-Grade Electrical Isolation

Each input channel is isolated at 5,000 Vrms, with an additional 2,000 Vrms on ECG and EDA channels. This exceeds standard safety requirements and aligns with medical-grade equipment protocols, giving reassurance when working in sensitive government or law enforcement contexts.

Expansion-Ready Architecture

A built-in expansion port supports future sensor integration, ensuring the system can adapt to evolving polygraph methodologies without requiring a full hardware replacement.

Compatibility with Existing LX6 Accessories

The LX7-S is backward-compatible with LX6 peripherals—such as cuffs, pneumo tubes, EDA electrodes, and activity sensors—allowing UK examiners to upgrade their Data Acquisition System (DAS) without replacing their entire kit.

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Complete System Package

The LX7-S package is supplied ready for deployment, including:

• LX7 Data Acquisition System

• LXEdge Software Suite with OSS-3 scoring algorithm

• Photoelectric PPG Sensor

• ECG Integration Channel

• Activity Sensor

• Vented Pneumo Chest Assemblies (Silver and Blue)

• Repositionable EDA Electrodes with reusable snap connectors

• Blood Pressure Cuff and Pump Bulb

• DAS Storage Pouch

• Professional Targus Backpack

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Technical Specifications