University of Waterloo: Final project combats physical strain in medical imaging

Diagnostic medical ultrasound imaging requires sonographers to apply continuous pressure to the patient with an ultrasound probe over an extended period. This clinical imaging modality demands precise positioning and consistent image quality over long durations.

The Capstone Symposium team at the University of Waterloo in Ontario, Canada, tackled this problem for their final project. In their research, the students determined that a solution was needed to address this highly repetitive and physically demanding workflow. medical to contribute to innovation. They found that almost ninety percent of sonographers suffer from occupational pain, with eighty-three percent of respondents citing the physical exertion involved in using ultrasound equipment as the main cause of their discomfort.

Around biomechanical To solve a clinical challenge, the student team developed the Load Assistance for Reduced-Strain Sonography-System, known as the LARS system. LARS is a semi-robotic articulated arm designed to assist in applying force to the probe while the sonographer retains full control of the procedure.

Unlike large and expensive robotic alternatives, this system integrates directly into existing clinical workflows, providing support without interfering with established scanning methods used by medical professionals. See a Demo release of LARS by Progressive Automations on Instagram.

Integration of force sensors into medical robotics

Developing a system that responds naturally to human interactions requires highly precise force feedback. The student team integrated the WMC-110 Sealed Stainless Steel Miniature Load Cell of interface as well as a DMA2 DIN Rail Mount signal conditioner into the structural design. The miniature force sensor is positioned directly above the ultrasound fastening mechanism to measure the force exerted on the patient in real time.

HOW DOES IT WORK? The sensor continuously feeds data into a closed-loop control system. This architecture relies on an outer admittance loop and an inner PID position loop. The outer loop serves as the primary force sensing layer, where an admittance controller handles the error between the target force and the force measured by the load cell. This position error is then passed to the inner PID controller, which evaluates the feedback from the linear actuator and adjusts the position accordingly. The signal conditioner converts the load cell's output signal into a usable 0–3,3 V signal for proper communication with the microcontroller unit.

TIPP: Read the full Interface case study: University of Waterloo LARS Project Redefines Sonography Application.

LARS project results and academic recognition

The integration of precise force feedback enabled the LARS system to achieve a rapid response time of 0,12 seconds rise time and no overshoot. This responsiveness ensures consistent, stable force application during a live examination. The system successfully maintains the force level selected by the operator, dynamically adapting to subtle movements—including the patient's breathing or coughing.

The LARS final project achieved significant recognition in the academic and engineering community and received several awards for its technical implementation and design fidelity:

• Norman Esch Entrepreneurship Award (2026): Awarded for identifying a clear market need and demonstrating a viable commercial pathway to clinical implementation.
• Biomedical Engineering Capstone Best Prototype Winner (2026): Awarded to the team for the prototype with the highest accuracy within the department.
• Baylis Medical Capstone Design Award (2025): Recognized for its innovative and technically complex design with a strong biomedical focus.

Project participants: The Capstone Symposium team from the University of Waterloo, consisting of Luke Coulter, Alexa Daly, Rylin Soto, and Serena Wittenberg (pictured above). Images and technical resources are credited directly to the University of Waterloo.

Interface invests in the engineers of tomorrow

The success of LARS project This underscores the vital relationship between academic institutions and precise metrology tools and resources. Providing fundamental hardware support to engineering students enables the transition from theoretical design to highly accurate, functional prototypes. This collaborative investment helps prepare the next generation of engineers to tackle complex, real-world problems in the fields of engineering, technology, and mathematics. Biomedicine, Robotic and industrial automation to solve.

To ensure that students and faculty have access to resources for advanced testing and final projects, academic programs can utilize dedicated research funding structures. Interface offers Educational support and discount programs to help university test labs and student teams procure high-precision instrumentation within their budget constraints.

We are carrying on our investment legacy in measurement technology and education through our ForceEDU program fort, a focused online resource hub with materials and references to support learning about metrology, force measurement and testing procedures.