Intravenous infusion therapy has helped to save and preserve the lives of millions of patients worldwide. Perhaps one of the most generic and widely used medical devices, infusion pumps are commonly used to deliver medications and nutrients to patients in hospital or ambulatory settings. With such a wide variety of uses, these pumps are an indispensable asset to doctors and nurses everywhere. 

The Role of Sensors in Infusion Pumps

While other sensing technologies may be present on many infusion pumps, the two primary types of sensors found on any infusion pump are bubble sensors to prevent delivering large doses of air to a patent’s circulatory system, and occlusion sensors to prevent tube blockages that could lead to dangerous venous pressures or improper dosing. 

Where Some Infusion Pumps Fall Short

These two sensors play a critical role in protecting patient safety; however, in an attempt to reduce costs as much as possible, some infusion pump manufacturers have opted for lower cost alternatives to robust and proven sensor technology. 

For example, optical bubble sensors can be a lower cost alternative to the more commonly used ultrasonic bubble sensing technology; however there are many disadvantages of optical sensors. Disadvantages can include sensitivity to ambient light variation, sensor degradation, and temperature sensitivity. A more detailed explanation can be found in our Frequently Asked Questions

Additionally, some infusion pump manufacturers have opted to detect tube occlusions using ultrasonic occlusion sensors instead of the more proven strain gauge force sensor technology. While we have the technology and expertise to design and manufacture such ultrasonic occlusion sensors, we’ve determined that they simply don’t work reliably enough in the vast majority of applications. Sensor output is significantly affected by too many external factors, such as micro-bubbles, the properties of the tubing, and non-repeatability of tube loading. While ultrasonic occlusion sensors may seem like a less expensive option, they may end up being more expensive in the long run, especially when you consider the costs of deploying an unreliable sensor.

We’ve worked with companies to replace their existing ultrasonic occlusion sensors with our thin film load cell technology due to excessive field failures that lead to caregiver complaints and contribute to alarm fatigue.

How Custom Sensors Can Help

We at SMD Sensors can produce a combination of custom bubble sensors, custom occlusion sensors, and custom load cells to combat these common failings and maintain the highest quality standards to ensure patient safety. 

Alternatively, if you’re designing a new generation of “smarter” infusion pump or similar product, you might consider adding a Disposable In-Line Flow meter or a Clamp-On Ultrasonic Flow meter to provide real-time accurate dosing information and better control pump flow rates. 



For more information or to reach our engineers, contact us!