Multi-Axial Breath Delivery System
KEA TECHNOLOIGES INC.
(LITTLETON, MA)
​Project Summary:
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This project built upon a first-generation internal test platform designed to deliver both sober and dosed breath samples that accurately mimic human breathing conditions within a vehicle. The system is capable of delivering controlled breath samples at six standardized seating positions, ranging from a 95th-percentile male to a 5th-percentile female occupant.
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The platform consists of five primary subsystems: a gas blending system to mix gases at precise concentrations, an in-vehicle unit providing horizontal and vertical motion control, a nasal and oral breath delivery passage, an electronics enclosure housing motion control and data acquisition components, and a gas delivery line connecting the blending system to the in-vehicle unit. The original system served as an internal proof-of-concept with the long-term goal of evolving into a more productized solution.
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Note: Due to confidentiality restrictions, detailed CAD models and prototype images are not shown on this site. Public demonstration footage and media coverage are available for interview review.
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OBJECTIVES & REQUIREMENTS
This project was the second-generation iteration of an internal test platform designed to deliver controlled breath samples that accurately replicate a human breath within a vehicle. The system delivers both sober and dosed breath samples at six standardized seating positions, ranging from a 95th-percentile male to a 5th-percentile female occupant.
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The primary objective of the second-generation effort was to integrate humidity into the breath delivery path to more closely mimic real human breath. This introduced a critical requirement: all components downstream of humidity introduction needed to be heated sufficiently to prevent condensation and ensure stable, repeatable output.
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Additional objectives included reducing the overall form factor and weight of the in-vehicle unit where possible, implementing a repeatable setup position in the vehicle, improving motion system reliability, and modifying the nasal passage to allow for angular adjustment during testing.
CONSTRAINTS & DESIGN CONSIDERATIONS
This phase of the project was executed under several constraints. Midway through development, the chemistry and electrical teams experienced significant turnover, resulting in limited in-house expertise for gas blending, heating, and electrical integration. While some initial modifications were completed prior to this transition, the system had not yet been validated as a fully integrated platform.
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Schedule constraints required delivery of a functional system within approximately two months, limiting the feasibility of large-scale redesigns. A reuse-first approach was taken to minimize time and cost, requiring much of the existing first-generation hardware to remain unchanged. Certain system geometry—such as vertical actuator height—was required to stay fixed to maintain compatibility with the original platform.
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Design decisions therefore needed to balance improving system performance while working within tight schedule, resource, and reuse constraints.
Engineering Analysis and Design Validation
Initial system-level testing revealed multiple issues, including condensation in the breath path, unstable flow rates, back pressure in the gas blending system, electrical faults affecting valve operation, and incorrect motion behavior from the linear actuators.
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Condensation was traced to underperforming heat tape that could not reach required operating temperatures, confirmed through thermocouple measurements. Flow instability and back pressure were caused by mixing high-flow gases into low-flow sections and by insufficient tubing diameter. Electrical issues were identified through independent bench testing of ball valves and mass flow controllers, leading to replacement of faulty components. Motion issues were traced to incorrect wiring of motor controllers, identified by tracing wiring and verifying against wiring diagrams.
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Design validation included flow testing using manual flow meters, extended breath delivery testing across multiple durations to confirm elimination of condensation, and verification of stable chemistry instrumentation readings. Humidity and BrAC outputs were validated using chemistry equipment under multiple dosing scenarios, confirming alignment with expected values.
MANUFACTURING, PROTOTYPING, & ITERATION
Significant prototyping and iteration were required to stabilize the system. The heated gas delivery line was rebuilt using upgraded heat tape with integrated temperature control and improved insulation. Tubing diameters were increased in high-flow sections to reduce restriction and back pressure. The gas blending system layout was reorganized so low-flow components fed into high-flow components, improving overall system stability.
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Electrical wiring for motion control components was corrected and reorganized to improve clarity, reliability, and serviceability. Multiple test-build iterations were performed to evaluate changes, isolate remaining issues, and confirm improvements prior to full system reassembly.
These iterative efforts transformed the system from a partially functional prototype into a stable and repeatable test platform.
RESULTS, PRODUCTION STATUS & SKILLS
Results and Production Status:​
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The system is currently in active use as an internal test platform for vehicle-based testing and ongoing data collection. It enables repeatable, standardized breath delivery without reliance on human test subjects and serves as a critical tool for evaluating breath alcohol detection technology and informing future productization efforts. Building on the success of the current platform, two additional systems are planned with targeted design improvements informed by ongoing testing and data collected from the existing unit.
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This project demonstrates system-level problem solving, structured troubleshooting, and the ability to adapt to shifting responsibilities while maintaining focus on delivery. Technical domains involved included mechanical design, fluid and gas systems, thermal management, electrical systems and wiring, motion control, and system assembly.
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Skills Demonstrated:
​Tools and methods used included Onshape for CAD design, PowerPoint for wiring diagrams, thermal testing using temperature controllers and thermocouples, flow testing with mass flow meters and manual flow meters, and chemistry equipment to validate BrAC output based on ethanol concentration.