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Custom Bubble & Occlusion Sensors For Ablation Cooling Pumps

Market: Medical | Product Line: Bubble Sensor & Occlusion


Medical devices use RF ablation to treat many medical issues, including heart issues, tumors, and back pain. A typical ablation system is made up of an RF generator, control and monitoring equipment, the antenna, and a cooling pump.

Customer Challenge:

In need of a sensor with the ability to detect bubbles that are pass through the device both upstream and downstream of the pump. In addition, the pump device also monitors the tubing for occlusions (ie., blockages) that may occur.

SMD Sensor Solution:

Strain Measurement Devices designed a custom bubble and occlusion sensor for medical device pumps. Working to to minimize the space required for each sensor offering a single sensor that can offer both a bubble sensor and an occlusion sensor in one small package.

Bubble Sensors work through the use of ultrasonic sound and proprietary control board software to selectively recognize (and reject) a targeted bubble size. SMD has in-house bubble generators capable of producing (repeatability) bubbles sizes of ½ micron and larger. Therefore, we can calibrate the sensor to “ignore” certain smaller size “nuisance” bubbles and monitor those sizes considered critical to our customer. Sizes range from 1/16” OD tubing to ½” OD tubing.

Occlusions cause an increase in pressure downstream of the pump and this expands the tubing and presses down on our miniature and accurate load cell. Occlusion sensors can reliably sense an “occlusion event” by triggering when rapid increase in pressure exceeds the customers predetermined value. SMD sensors use our proprietary “thin film sputtering” manufacturing process which is similar to how small semiconductors are made. This process has important benefits such as miniaturizing the sensor and offering excellent repeatability, accuracy, and long term stability.