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Biocompatibility and Sub-1mmHg Accuracy Enable Invasive Monitoring
Release Date:2025/7/28 15:52:45

Core Technical Advantages: Performance Leap Over Conventional Medical Sensors

High-precision pressure sensors for medical devices deliver transformative improvements in measurement accuracy, biocompatibility, and long-term stability compared to conventional medical-grade pressure sensors. According to the 2024 Medical Sensor Technology White Paper, these sensors achieve a full-scale (FS) accuracy of ±0.05%—a 50% improvement over conventional medical sensors (±0.1% FS)—and a measurement resolution of 0.1mmHg, enabling detection of subtle pressure fluctuations in invasive blood pressure (IBP) monitoring. Critically, they meet ISO 10993-5 biocompatibility standards: after 30 days of in vitro cell exposure, the sensor’s surface exhibits <0.5% cytotoxicity, compared to 2% for conventional sensors, reducing tissue irritation risks. Additionally, their long-term drift rate is <0.01% FS/year, 75% lower than the 0.04% FS/year of traditional devices, ensuring reliable performance for implantable applications (e.g., ventricular assist devices) over 5+ years.

Key Manufacturing Breakthroughs: Biocompatible Coatings and Microfabrication

Two pivotal innovations have advanced the commercialization of medical-grade high-precision pressure sensors. First, titanium nitride (TiN) biocompatible coatings: Using atomic layer deposition (ALD), a 50nm-thick TiN layer is deposited on the sensor diaphragm, replacing conventional silicone coatings. This coating reduces protein adsorption by 80% (from 20μg/cm² to 4μg/cm² after 72 hours in human serum) and enhances corrosion resistance—after 1000 hours of immersion in simulated body fluid (SBF), the sensor’s electrical resistance increases by <2%, compared to 15% for silicone-coated sensors. The breakthrough is validated in a 2024 study published in IEEE Transactions on Biomedical Engineering. Second, deep reactive ion etching (DRIE) for microdiaphragms: A DRIE process creates 5μm-thin silicon diaphragms with a uniform thickness variation of <0.1μm, compared to 0.5μm for wet etching. This precision reduces sensor hysteresis from 0.08% FS to 0.02% FS, critical for accurate pressure readings in low-pressure ranges (0-300mmHg) typical of respiratory systems.

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Industrial Applications: Deployment in Critical Medical Scenarios

In invasive blood pressure (IBP) monitoring systems, these high-precision sensors reduce measurement error from ±2mmHg to ±0.5mmHg, enabling clinicians to detect early hypotension (systolic pressure <90mmHg) 1.5 minutes faster than conventional sensors, according to data from a leading hospital’s clinical trial. This early detection reduces the risk of organ hypoperfusion by 30%. For mechanical ventilators, the sensors’ 0.1mmHg resolution allows precise control of positive end-expiratory pressure (PEEP), maintaining it within ±0.2cmH₂O of the target value—compared to ±1cmH₂O for traditional sensors—lowering the incidence of ventilator-induced lung injury (VILI) by 25%. In minimally invasive surgical (MIS) instruments (e.g., laparoscopic trocars), the sensors monitor abdominal insufflation pressure (12-15mmHg) with a response time of 5ms, 80% faster than conventional sensors (25ms), preventing over-insufflation-related complications (e.g., pneumothorax) in 99.2% of procedures, vs. 96.5% for traditional setups.

Existing Challenges: Cost, Sterilization Compatibility, and Miniaturization

Despite their clinical value, medical-grade high-precision pressure sensors face three key challenges. Cost remains a barrier: The ALD TiN coating process adds 40% to sensor manufacturing costs, and DRIE equipment investment is 3x higher than wet etching tools, resulting in a unit cost of approximately  4). While scale-up to 8-inch wafer production is projected to reduce costs by 30% by 2026, this still limits adoption in low-resource healthcare settings. Second, sterilization compatibility: Autoclaving (121℃, 15psi, 20 minutes) causes a 0.03% FS accuracy loss per cycle—after 50 cycles, accuracy degrades to ±0.2% FS, exceeding clinical requirements. Alternative sterilization methods (e.g., ethylene oxide) add 20% to processing time and require aeration to remove residues. Finally, miniaturization vs. performance: Reducing sensor footprint from 3mm×3mm to 2mm×2mm (for use in pediatric catheters) increases noise floor by 15% (from 0.05mmHg to 0.0575mmHg), requiring additional signal filtering that increases power consumption by 10%—a tradeoff for battery-powered portable devices.