More accurate respiratory gas sensing for ventilation
In addition to our developments in pulse oximetry and our own capnography module CAP201, we continue to work on innovative sensor solutions to advance our customers and medical technology in Germany. This has resulted in a new patent for respiratory gas measurement, which was disclosed in April 2024, and we would like to introduce it to you here.
What Exactly Is It?
This patented invention describes an innovative method for measuring gas samples in a sidestream with the highest temporal resolution. The technology enables precise analysis of the gas composition in flowing gases or gas mixtures and is ideally suited for applications in medical technology, ventilation, and industrial analysis.
Functionality
The device takes gas samples directly from a main stream without affecting it. The samples are passed through a gas reservoir, a measuring device, and a suction pump. The measuring device, e.g., with CO2 and O2 sensors, analyzes the gas composition in real-time. The temporal resolution of the measurement can be flexibly adjusted by controlling the suction rate. This results in smaller volume samples due to slower extraction rates and larger relevant samples due to fast extraction rates. These flow alternately through the tubing and ultimately the sensor. At slow extraction rates, the larger samples remain in the sensor longer, resulting in additional measurement points for the same relevant sample. The resulting temporal resolution is therefore higher than the nominal temporal resolution of the sensor. This makes it possible to temporarily measure faster than the sensor actually allows.
Advantages Over Existing Solutions
Compared to conventional mainstream and sidestream methods, the patented technology offers significant advantages:
- Up to 5-fold Improvement in Temporal Resolution: Allows precise analysis of fast processes such as breathing or ventilation.
- Real-Time Results: Provides data in real-time, which is crucial for time-critical applications such as ventilation, anesthesia, and process control.
- Extended Measurement Range: Allows the determination of parameters that are not accessible with conventional methods, such as fiO2 and etO2.
- Reduced Delay: Minimizes distortions caused by gas mixing in the sample system, enabling more precise measurements.
- Robust Measurements: even at high respiratory rates, ideal for monitoring newborns.
Flexible Control of Temporal Resolution
The temporal resolution of the measurement can be flexibly adjusted by controlling the suction rate to meet the specific requirements of the application. For example, a higher temporal resolution can be chosen for monitoring newborns or patients with limited lung function – while for long-term monitoring or other industrial sectors a lower resolution is sufficient.
Medical Applications
- Medical Patient Monitoring: Monitoring CO2, oxygen, and other gases in the breath, including in newborns.
- Ventilation: Optimization of ventilation parameters based on real-time gas analysis, even in high-frequency ventilation (HFOV) and under resuscitation (e.g., CCSV – Chest Compression Synchronized Ventilation).
The extraction rate for sampling gas from the main flow can be adjusted to significantly increase the
effective time resolution of the measurement of individual gas samples.
Conclusion
The patented technology for sidestream gas analysis offers a number of advantages over existing solutions and is ideal for a variety of applications in medical technology, especially in ventilation. The high temporal resolution and flexible control enable precise and reliable monitoring of gas compositions in respiratory gases. The patent (DE 10 2022 127 681.3) is another element in our efforts to develop innovative, safe, and precise medical technology to bring high-quality devices to market faster together with our partners.