The Superior Architecture for Sensing Pressure
Using Superior Sensor Technology’s proprietary NimbleSenseTM architecture allows highly differentiated advanced pressure sensing systems to be created from a design toolbox of technology building blocks, greatly improving system performance in the end application, while providing enhanced features and cost-optimized manufacturing solutions. We call this fully integrated platform the industry’s first System-in-a-Sensor.
The NimbleSense architecture incorporates processing intelligence with signal path integration and proprietary algorithms to provide sensor sub-system integration with maximized sensor performance. Choosing from a smorgasbord of proven and tested building blocks, Superior Sensor Technology design experts integrate the appropriate blocks into a pressure sensor sub-system to achieve optimized performance for the customer’s application requirements.
These different pieces provide significant design flexibility to satisfy customer goals. With these highly-integrated subsystems, a user can quickly and easily develop the pressure sensing solution required in their specific end product by simply adding a few low-cost external components. The plethora of technology building blocks in the NimbleSense architecture enables a 5 to 10x performance increase as well as a variety of application-specific features.
Flexibility is at the core of the NimbleSense architecture and the System-in-a-Sensor approach. This unique technology allows you to quickly prototype and design the sensor into your product, support multiple product lines with one particular sensor, add new capabilities and application specific features and reduce system cost through lower component count and greater product reliability. Based heavily on customer feedback, the Superior Sensor Technology engineering team is constantly innovating and introducing new building blocks in the NimbleSense architecture.
One device can support up to 8 different pressure ranges, and each pressure range is factory calibrated and optimized ensuring no degradation in total error band, accuracy or stability regardless of the range selected. This eliminates the complexity and headaches of working with multiple sensors.
Instead of having to research, purchase and design-in multiple parts, a single Multi-Range part simplifies both the design and manufacturing of a product. Designing in the same part throughout your designs is much more efficient than having to select multiple components. When you design in each of the Superior pressure sensors, the setting of the pressure is done via a single software command. It’s that simple. Add the fact that there is only one product to inventory, and your manufacturing team will also appreciate the value of Multi-Range!
Benefits of Multi-Range Technology include:
- Design flexibility with ability to ‘tweak’ pressure range throughout 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
To ensure the utmost accuracy in medical devices, the company has developed its proprietary Z-Track technology that virtually eliminates zero drift. Zero error reduction is critical in medical devices such as Spirometers, where an inaccurate reading can have life changing consequences.
Z-Track provides greater accuracy to devices such as spirometers, resulting in more effective diagnosis and better treatment plans. As you can see from the figure, Z-Track maintains minimal zero-point deviation with results that are consistent regardless of elapsed time. When combined with the Superior’s position insensitivity capability, the company’s pressure sensors provide the most accurate readings for all types of spirometry equipment including handheld and desktop units. Not only are you certain that the device has virtually eliminated all zero errors, but you can be sure of accurate readings regardless of how the spirometer is positioned or used.
Benefits of Z-Track Technology include:
- Eliminate zero errors to ensure the most accurate spirometer readings in the industry
- Consistent performance regardless of elapsed time
- Extremely fast data transfer rate
- More effective medical diagnoses and treatment plans
Closed Loop Control adds capabilities to set and maintain flow rates via pressure management by directly controlling motors, valves and actuators. Superior offers the option to have this capability integrated into the sensor in order to more effectively set and maintain flow rates by directly controlling motors, valves and actuators to maintain flow rate targets.
The integrated Closed Loop Control design significantly reduces loop delays in the electronic circuit by up to 100x. This integrated solution also eliminates the need to design and implement a complex control loop system, resulting in more efficient, more reliable and less costly products. Closed Loop Control is of extreme value in medical respiratory devices such as ventilators and CPAP, as well as in air quality measurement products.
The figure below shows a block diagram of an implementation of the Superior Closed Loop Control for an air quality application. In order to effectively measure the air quality, we require maintaining a constant/known airflow through the viewing window. The differential pressure across the venturi directly measures the flow into this viewing window. The system sets a target pressure level across the venturi and the differential pressure sensor automatically increases or decreases the drive to the pump to maintain the targeted differential pressure, ensuring a constant airflow into the viewing window. This is accomplished with the NimbleSense closed loop circuit used in combination with the company’s proprietary noise filtering, resulting in greater than 100x reduction in loop delay.
Benefits of the integrated Closed Loop Control include:
- Greatly reduce loop delays to improve accuracy and responsiveness of your product
- Improve the reliability of your product by eliminating discrete parts
- Reduce your overall system costs
- Minimize system power and heat
- Simplify your product design
- Speed your time to market
Superior’s advanced digital filter is a multi-order filter that utilizes advanced filtering capabilities on the front-end of the sub-system to eliminate critical noise created by fans, blowers or other dry air/gas sources prior to reaching the pressure sensing sub-system. The NimbleSense advanced filtering capability removes sensor induced mechanical noise before it becomes an error signal that can adversely impact overall system performance. In customer deployments where our sensor replaced a competing component, we have seen greater than 10x reduction in sensor induced noise, thus greatly improving the SNR of the sensor output. In very low pressure systems, the improvement is even more significant.
Incorporating both standard and optional digital filters, this feature provides significantly better noise reduction and eliminates the need to design an external filtering system, resulting in more efficient, more reliable and less costly products. Our advanced digital filtering is optimized for each application to ensure mixed sampling noise is kept well below the noise floor. By removing the mechanical noise, we maximize overall system performance.
The example below is of a 4th order FIR filter customized to block pump noise above 50 Hz, which has noise of equal magnitude as the signal of interest. The lower graphs show the resulting impact of the advanced digital filtering.
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.
As all of Superior’s pressure sensors have an extremely low noise floor, theoretically power line interference can be ‘heard’ when taking measurements. The integrated 50Hz/60Hz notch filter eliminates this noise so you maintain the advantage of having such a low noise floor pressure sensor without any external interference. With the notch filter seamlessly integrated in the pressure sensor module, the sensor blocks out the interference caused by these frequencies before it reaches the user application. Further, as the notch filter is internal to the sensor module, it eliminates the need for an engineer to design and implement an external notch filter. This feature removes an external notch filter, so the overall system is more efficient, more reliable and less costly.
- Eliminate the noise from the power grid and AC devices before it reaches the sensing element
- Simplify product design with an integrated approach
- Speed time to market by not having to design and/or implement an external notch filter
- Lower overall system cost as an external notch filter is no longer required
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.
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.
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.
- 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.
- Flexibility with 3 modes of operation
- Lower system cost as 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.
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NimbleSense, Multi-Range, Z-Track and Self-Aware are trademarks of Superior Sensor Technology.