My project partner Ian and I, designed, built, and tested a low-cost syringe pump. This was done in collaboration with the Digital Health Innovation Lab (DHIL) under the guidance of Dr. Mark Answermino and Dr. Guy Dumont.
Safe surgical care is an essential medical resource which is unavailable to billions of people in developing nations. Intravenous anesthesia plays a critical role in surgery, however conventional syringe pumps are too expensive for widespread use in low-resource settings. To address this issue, we developed a low-cost syringe pump using less than $25 of components. To meet the demands of surgery, we aimed to achieve an accuracy of ±15% at drug delivery rates of 10-200 mL/hr.
The syringe pump design employs a simple 3D printed chassis, which holds two syringes back-to-back. An air pump and valve drive one syringe, forcing anesthetic from the other syringe. Our solution substitutes expensive precision components for feedback-based control. Inlaid copper strips capacitively sense changes in the syringe volume, and a Raspberry Pi Zero uses this feedback to control pumping and deliver anesthetic smoothly. The entire system runs from a powered USB connection.
Testing over a wide range of flow rates, we found the pump met the design specifications for infusion rate accuracy. This testing employed an analytical balance to track the flow of water from the pump. These results demonstrate the viability of feedback-based syringe pump design and provide a foundation for future development. Further refinement and validation of the control algorithm will improve robustness and accuracy. Careful consideration of the surgical environment and consultation with healthcare providers will help ensure successful deployment of the device in field trials.
