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LX7-S Polygraph System – Technical Overview for Polygraph Professionals
The LX7-S Polygraph System is the next evolution in computerized polygraph instrumentation. Designed for professional examiners, trainers, and researchers in the field of psychophysiological detection of deception (PDD), the LX7 delivers precise, high-resolution physiological data in a modular and field-ready format. It combines advanced sensors, robust hardware, and future-focused features to support a wide range of polygraph testing environments—from government to private practice.
Advanced Physiological Monitoring
Enhanced PPG Sensitivity
The LX7 introduces an upgraded photoelectric plethysmograph (PPG) sensor, capable of detecting subtle and rapid fluctuations in blood volume. This translates into more reliable cardiovascular data, especially for examinees who traditionally present low-amplitude pulse signals.
Streamlined EDA Signal Acquisition
With a broader galvanic skin response (GSR) range and stable 3.59 µA current, the LX7’s EDA channel improves signal clarity and consistency. This allows for more dependable electrodermal readings across examinees with varying skin resistance profiles.
New ECG Channel for Pulse Arrival Time (PAT)
A major advancement in the LX7 is the addition of an ECG channel that enables Pulse Arrival Time (PAT) measurement. PAT is the time difference between the heart’s electrical signal (ECG) and the mechanical pulse detected by the PPG. This time-based measure is directly correlated with blood pressure and has been shown to be as discriminative as traditional cardiograph readings in detecting deception.
Ergonomic Hardware & Modular Design
Modern Enclosure Design
The LX7 is housed in a newly designed, curved polycarbonate/ABS enclosure that promotes better cable management and examiner workspace organization. This ergonomic upgrade reduces clutter and improves workflow during examinations.
Medical-Grade Isolation
To ensure maximum safety, all input channels are isolated at 5,000Vrms, with an additional 2,000Vrms isolation on ECG and EDA channels. This exceeds industry norms and meets medical-grade equipment standards.
Expansion Port for Future Sensors
A built-in expansion port supports integration of next-generation physiological sensors under development, ensuring the LX7 can adapt to evolving testing methodologies without needing full system replacement.
Easy Upgrade from LX6
The LX7 maintains full compatibility with LX6 accessories, including cuffs, pneumo tubes, EDA electrodes, and activity sensors. Current users can upgrade the DAS (Data Acquisition System) only, preserving their existing peripheral investment.
Complete System Package
The LX7-S package includes everything needed for immediate deployment in the field or lab:
- LX7 Data Acquisition System
- LXEdge Software Suite with OSS-3 algorithm
- Photoelectric Plethysmograph (PPG) Sensor
- ECG Integration Channel
- Activity Sensor
- Vented Pneumo Chest Assemblies (Silver and Blue)
- Repositionable EDA Electrodes with 2 reusable snap connectors
- Blood Pressure Cuff and Pump Bulb
- DAS Storage Pouch
- Professional Targus Backpack
System Specifications – Detailed Breakdown
| Specification | Explanation |
|---|---|
| Dimensions 8.66” x 3.61” x 1.21” (22.0 x 9.2 x 3.1 cm) |
Compact, lightweight size ideal for mobile and desktop setups. Ergonomically designed for better handling and portability. |
| Power Source USB connection |
Powered entirely via USB—eliminates external power adapters and simplifies setup. Enables simultaneous data and power transmission. |
| Isolation 5,000Vrms (all channels) +2,000Vrms (ECG & EDA) |
High electrical isolation protects examinees and equipment. ECG and EDA channels include additional protection, exceeding typical standards for safe physiological monitoring. |
| Enclosure Material ABS/Polycarbonate blend |
Impact-resistant and heat-resistant materials ensure durability in field use and compliance with flammability safety standards (UL 94V-0). |
| Data Transfer Rate 180 samples/second across all channels |
Full-speed data acquisition per channel allows for real-time, high-resolution monitoring without bandwidth sharing between sensors. |
| A/D Resolution 32-bit analog-to-digital conversion |
Captures even minute physiological changes. Reduces noise, improves signal quality, and ensures precision chart output. |
| Certifications CE Certified, ASTM Compliant, UL 94V-0 |
Meets international standards for safety and electromagnetic compatibility. ASTM E1954 compliance ensures polygraph-specific performance reliability. |
Sensor Channels & Input Specifications
| Sensor | Channels | Technical Details |
|---|---|---|
| Cardio | 1 | 0–140 mmHg blood pressure range |
| Pneumo | 2 | Vented assemblies with extended pressure sensitivity |
| EDA (GSR) | 1 | Constant current 3.59 µA; 10 kΩ – 4.0 MΩ range; 2000Vrms isolation |
| PPG | 1 | 940 nm wavelength; 0.47 s time constant |
| Activity | 4 | 0–4V analog input |
| ECG | 1 | Additional 2000Vrms isolation; supports PAT |
Summary
The LX7-S Polygraph System combines technological innovation with examiner-focused design. From enhanced physiological monitoring to upgradable modular architecture, the LX7 provides examiners with a robust and future-ready platform. Whether used in criminal investigations, security vetting, or private assessments, the LX7 meets the demands of modern polygraph science with precision, safety, and efficiency.
