The "Kessel Function"
Ben was a core part of the Ivenix engineering team and contributed to the development of its infusion system in many ways. One of the projects he worked on was to refine how they calibrate the pump during manufacturing to ensure that it always delivers fluid accurately.
The Ivenix pump uses pneumatic pressure to draw fluid in from a bag and push it out to the patient. The measurement and control system is based on ideal gas laws which dictate that any change in the volume of a gas results in a proportional change in pressure. The trick was that the calculations they were doing assumed a contact temperature which was not true in actual practice. The difference between assumption and reality resulted in errors in flow output, but the root cause of the problem was not immediately obvious.
Ben dug in and approached the challenge with a mix of creative problem solving and very deep knowledge of physics. He determined that there was a temperature differential between two portions of the pneumatic system and further determined how the ambient temperature of the surroundings during pump calibration affected the internal temperatures. In the end he worked this knowledge all down to a temperature compensation calculation that is used during calibration. After implementation, this compensation function fully resolved the flow errors they had been seeing, and that calculation is used to calibrate every pump they build.
His work to solve this problem was a major contribution Ben was known for, and his intuition to look into an aspect of the problem that others hadn’t thought of resulted in this innovation. To honor this contribution and his memory, Ivenix has officially named the temperature compensation calculation the “Kessel Function” in both its design documentation as well as the software itself.
Provided by Ben’s manager at Ivenix, Ben Powers
The Ivenix pump uses pneumatic pressure to draw fluid in from a bag and push it out to the patient. The measurement and control system is based on ideal gas laws which dictate that any change in the volume of a gas results in a proportional change in pressure. The trick was that the calculations they were doing assumed a contact temperature which was not true in actual practice. The difference between assumption and reality resulted in errors in flow output, but the root cause of the problem was not immediately obvious.
Ben dug in and approached the challenge with a mix of creative problem solving and very deep knowledge of physics. He determined that there was a temperature differential between two portions of the pneumatic system and further determined how the ambient temperature of the surroundings during pump calibration affected the internal temperatures. In the end he worked this knowledge all down to a temperature compensation calculation that is used during calibration. After implementation, this compensation function fully resolved the flow errors they had been seeing, and that calculation is used to calibrate every pump they build.
His work to solve this problem was a major contribution Ben was known for, and his intuition to look into an aspect of the problem that others hadn’t thought of resulted in this innovation. To honor this contribution and his memory, Ivenix has officially named the temperature compensation calculation the “Kessel Function” in both its design documentation as well as the software itself.
Provided by Ben’s manager at Ivenix, Ben Powers