Ventilator Pressure Sensors
Extreme Resolution and Oversampling Improve Synchrony
Ventilators Require the Highest Reliability
Medical ventilators are sophisticated mechanical ventilation systems designed to move breathable air into and out of the lungs for patients physically unable to breathe on their own. Today’s systems are electronically controlled through embedded processing to tightly manage air pressure and flow characteristics to meet individual patient requirements. These systems are considered life-critical as system failures may result in serious harm to the patient. As such, these mechanical ventilators are carefully designed to ensure single points of failure do not harm patients.
The Ventilator industry manufactures the industry’s highest reliability products with appropriate features offered at acceptable cost levels. Identifying and replacing sensors prior to failure increases system reliability and has been shown to lower system alarm rates. This, in turn, saves lives.
VN Series Family of Pressure Sensors
The VN Series is a comprehensive set of pressure sensors for ventilator and high flow oxygen devices. The family of products includes sensors for measuring inlet (wall and tank), flow, inspiratory, expiratory, and barometric pressures. The series utilizes Multi-RangeTM technology to create the industry’s widest dynamic range, eliminating the need for fine-tuning or additional calibration.
- Eliminates the need for the ventilator to oversample sensor outputs, as the sensor oversamples at 12kHz and includes internal bandwidth filters to provide a clean > 1kHz data rate.
- Highest levels of accuracy and performance due to the architecture’s extremely low noise floor.
- Pure oxygen (O2) compatible.
- With optional advanced digital filtering customization and a 3-mode pressure switch, the VN Series is more than a pressure sensor – it is a pressure-sensing sub-system.
New Extreme Resolution Sensors
With the introduction of the VN Series, Superior Sensor Technology is taking resolution to the extreme! The product family has 24-bit output resolution, and we offer two extreme resolution sensors with approximately 18-bit effective resolution at high bandwidth. This is significantly higher than any other pressure sensors, and in critical high-speed applications like ventilators, the difference is significant.
The chart below shows the actual measured effective resolution of both VN extreme and standard resolution parts compared to several high-volume parts from competing companies. Not only do the VN parts support a wider bandwidth, but the gap in effective resolution continues to grow the higher the bandwidth (speed) requirement of the application.
As seen in the graph, at 200 Hz bandwidth the extreme resolution VN sensors have a 16x lower noise floor versus the best-performing competitive parts! At 500 Hz the gap in noise floor grows to at least a factor of 17! In addition, none of the competing parts have as wide a dynamic range as the VN Series sensors.
VN Series – Advanced Pressure Sensors for Ventilators
Family of Sensors for Ventilators and High Flow Oxygen Devices
Devices with two checks are better suited for that application versus those with one check
For an example of how the VN Series can be implemented in a mechanical ventilator, download the Ventilator Diagram.
For an example of how the VN Series can be implemented in a high flow oxygen therapy, download the High Flow Diagram.
FEATURES
- Inspiratory, expiratory, flow, inlet & barometric pressure sensors
- Highly integrated sensor with ADC and DSP
- Output Data Rate up to 1.09kHz
- 24-bit resolution (each selected range)
- Pure O2 compatible
- Up to 8 Selectable Pressure Ranges per Device
- Exceptional Zero Stability
- Selectable Bandwidth Filter from 1.0Hz to 500Hz
- Total Error Band less than 0.15% FSS
- Very High Accuracy ±0.05% of Selected Range
- Long Term Stability ±0.10% FSS
- Sensors for flow are available in high and extreme resolution
- Inlet & Barometric sensors include silicone gel protection
- Temperature Compensated 0°C to 50°C
- Fully Integrated Compensation Math
- Standard I2C and SPI Interface
Engineering Design Resources
3D Model & Configurator: VN Series
Select product requirements from the table to see the order part number. In addition, view & download 3D Models in native CAD format.
(model download requires registration at CADENAS PARTsolutions)
Getting Part Info…
CP301-SM06-R
PCB Viewer
Symbol
Footprint
90° Port Adapters
Depending on your product design, you may need the ports facing to the sides instead of the top. Superior offers highly reliable, high-quality adapters that plug into the two ports of our pressure sensors for easy implementation. With these 90° adapters, there is no need to worry about z-height.
90° adapters are available with and without o-rings:
KP-RAR: without o-rings
KP-ROR: with o-rings
Adapters are offered in packages of 50 and 1000.
Recommended NimbleSense Features for VN Series
A single device can accommodate up to eight different pressure ranges, with each range being factory-calibrated and optimized to maintain consistent total error band, accuracy, and stability. This alleviates the complexity and complications associated with working with multiple sensors. Utilizing a Multi-Range part streamlines both the design and manufacturing process, eliminating the need for researching, purchasing, and integrating numerous parts.
Implementing the same component in all designs enhances efficiency and ease, and pressure adjustments are conveniently controlled through a single software command. Moreover, Multi-Range provides the added benefit of a singular inventory item, adding value and convenience to manufacturing operations. In summary, the value of Multi-Range is apparent to both design and manufacturing teams alike.
Benefits of Multi-Range Technology include:
- Design flexibility with the ability to adjust pressure range throughout the development cycle
- Simplified product design with one sensor replacing up to 8 different sensors
- Ability to quickly develop product variants at different pressure ranges without changing hardware design
- Greater economies of scale by purchasing larger quantities of the same product
- Reduced manufacturing complexity and costs due to simplified calibration of sensors
- Up to 8x reduction in sensor inventory costs and product obsolescence
- Allows manufacturers to build fewer product variants, significantly lowering working capital requirements and inventory
Superior’s cutting-edge digital filter is a multi-order filter that leverages advanced filtering capabilities at the front end of the sub-system to eradicate critical noise caused by fans, blowers, or other dry air/gas sources before they reach the pressure-sensing sub-system. This is accomplished using the NimbleSense advanced filtering capability, which eliminates sensor-induced mechanical noise before it becomes an error signal that can negatively impact overall system performance. By replacing a competing component in customer deployments, our sensor has produced a more than 10-fold reduction in sensor-induced noise, significantly enhancing the SNR of the sensor output. This improvement is even more substantial in very low-pressure systems.
By incorporating both standard and optional digital filters, this feature offers considerably better noise reduction and eliminates the need to design an external filtering system, leading to more efficient, reliable, and cost-effective products. Our advanced digital filtering is fine-tuned for each application to ensure that mixed sampling noise is well below the noise floor. By eradicating mechanical noise, we maximize the overall performance of the system.
Below is an example of a 4th-order FIR filter that has been specifically designed to eliminate pump noise above 50 Hz, which has an equal magnitude of noise as the signal being monitored. The graphs illustrate the outcome of Superior’s advanced digital filter.
Benefits of the advanced digital filtering technology include:
- Greatly reduced system noise levels by 10x or more, especially important in very low pressure applications. For noise prone systems, an improvement of 100x to 1000x is not unreasonable.
- Eliminate noise sources such as fans and blowers before they reach the pressure sensing sub-system.
- Simplify product design with an integrated approach.
- Speed time to market by not having to design an external filtering system.
A pressure switch is a mechanical or electronic device that is activated when a certain pressure threshold or set point is reached. These failsafe response components instruct the system to perform an action if a certain pressure threshold is met.
Types of Pressure Switches
Fixed Pressure Switches
As their name implies, fixed pressure switches have pre-set, non-changeable pressure thresholds that are set by the pressure switch manufacturer. The device maker receives the pressure switch already configured and cannot change values. Examples where fixed pressure switches are common are certain types of medical devices, such as ventilators.
Variable Pressure Switches
With variable pressure switches, the threshold value can be set either by the device maker or dynamically in the field. If it is controlled by the device maker, when they build their product they select certain resistor pairs that control the voltage input that determines the threshold. Once they build the product, the threshold value cannot be changed.
In cases where the threshold can be set in the field, this is typically done via software or a mechanical knob/switch. In this scenario, the pressure switch is usually not implemented as a safety feature. A good example is with air filters – where depending on the system implementation, the threshold value needs to be adjusted to account for any head loss in the flow stream.
Superior’s pressure switch changes state depending on the measured pressure being above or below a certain threshold. This can be used as a fast response failsafe feature for overpressure conditions, and to provide other simplified on/off system feedback. However, unlike other more common pressure switches, the Superior Sensor pressure switch includes three modes for setting threshold pressure, one fixed and two variable:
- Fixed mode: Superior Sensor Technology sets the threshold and provides the ‘ready for use’ configured sensor (with integrated pressure switch) to the device manufacturer.
- Variable mode 1: The device manufacturer can configure and set the proper thresholds at the time of product manufacturing.
- Variable mode 2: Pressure thresholds are field programmable via software, so the pressure switch can be ‘tuned’ after product manufacture depending on the use case.
Benefits of Superior’s integrated pressure switch include:
- Flexibility with 3 modes of operation
- Lower system cost as the need for an external pressure switch is eliminated
- Smaller overall PCB footprint
- Improve the reliability of your product by eliminating external components
- Minimize system power and heat
- Simplify your product design
- Speed your time to market
With such a high demand for ventilators, it is critical that they continue to work without interruption. Eliminating failures before they become system alarms is a must. Implemented in close collaboration with partners, Superior’s proprietary Self Aware technology offers a capability that ensures maximum uptime and overall reliability.
Self Aware sensor technology tracks changes in error levels. By being part of a redundant system, the technology both eliminates a single point of failure service interruption and reduces false positives with respect to error notifications. Self Aware can reduce pressure sensor related alarm rates by up to 1000x.
If Self Aware technology is beneficial for your application, please contact us to discuss how we can implement this innovative feature to help differentiate your product.
Video Corner
VN Series Benefits Summary