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Jonathan Leary

Jonathan Leary

Lead Wearable Test Engineer

San Diego, California, US
(858) ###-####

Background


About

About

Lead Wearable Test Engineer at Dexcom for Next Generation Wearable CGM medical devices. Specializing in practical hands-on cross-disciplinary engineering, root-cause analysis and debugging, test method and equipment develepment, and cross-functinonal teamwork.

Work Experience

Work Experience

  • Dexcom: Mechanical Engineer II

    Apr, 2016 - Feb, 20258 years 10 months

    Lead Wearable Test Engineer - R&D Test & Analysis.

    • Led testing of Dexcom's next generation wearable platform from POC to V&V handover.

    • Led small team using NUD/ECO and risk-based approach to prioritize and execute characterization, cliff, and reliability testing at component and system level.

    • Test planning, p-diagrams, risk register, documentation etc.

    • Developed tests...

    • Developed equipment...

    • Electro-mechanical debugging of complex wearable systems. Worked as part of several mission-critical 'Tiger Teams' to find and prove root cause on issues such as Environmental Stress Cracking, Adhesive Delamination, Rapid Voltage Decline/Brown-outs, Battery Electrolyte leakage, and other product performance related issues.

    • Developed Windows software for NFC communication and test specimen preparation and tracking, DUT data parsing and automated analysis using SAS JMP API including normalization and filtering, chart generation, distributions, T-tests, etc.

    • Developed novel methods and semi-automated equipment for attaching 0402 passive SMD components to end of 0.25mm dia. coax wire to emulate specific test loads, without the use of solder or significant thermal exposure.

    • Measurement routines and fixtures

    • Instron method and fixture development, including advanced uses of strain input to capture dynamic analog electrical data from DUT, and Digital I/O to trigger and sync external measurement equipment such as DMM, Oscilloscope, or SMU during compression/tensile/shear testing.

    • Highly skilled with use of optical microscopes and physical tools such as scalpels, tweezers, soldering irons, hot-plates, alongside CAD/CAM systems such as bench-top milling machines, 3D-printing, automated epoxy and adhesive dispensing equipment, to dissect and debug devices, prepare novel device configurations for test, and enable rapid prototyping of small electro-mechanical devices.

    • Use of embedded systems to enable high-n testing with limited expenditure, e.g. recording data to SD card from many sensors on a shared I2C or SPI bus, logging current, voltage, temperature, humidity through various environmental conditions. Development of a small form-factor multi-sensor BLE enabled PCBA to measure temperature, ambient pressure, humidity, condensation droplet formation inside a thumbnail sized enclosure.

    • Developed POC for MongoDB database integration into test flow and equipment such as LabView test beds, custom windows software, to demonstrate benefits of centralized data storage and access across R&D test teams, enable dashboarding and automated reporting and documentation on platforms such as Confluence.

  • Fleet Fuel Testing: Manufacturing Technician

    Jul, 2014 - Mar, 20161 year 8 months

    Biofuel Test Kit manufacturing.

    • Manufacturing of test kits for visible clarity, entrained water, and microbial contamination of biofuels.

    • Developed fixturing to improve lot size, yield, and reduction of RSI risk.

    • Increased efficiency of manufacturing processes through implementation of sub-assembly batch processing and improved organization of material inputs and outputs.

Skills

Skills

  • CAD/CAM

    Solidworks, Onshape, MeshCam, Carbide3D

  • Programming

    C#: Windows development for custom test and equipment software, NFC/Serial/RS232 communication, SQL/MongoDB databases, .csv/.xlsx, JMP API for Statistics, O.C.R for report scanning and digitization, etc...

    C/C++ for embedded applications

    basic Python scripting

    Matlab

    JSL

    VBA(Excel)

  • Electronics

    Schamatics/PCB Layout: Eagle, KiCad

    Soldering: hand, air, hotplate, SMD 0201/QFN/BGA etc.

  • Rapid Prototyping

    3D-Printing: FDM: Bambu Labs, MarkForged, Creality. Resin: Stratasys, FormLabs, Elegoo, Anycubic

    CNC Mill, Laser-Cutter, General machine shop equipment.

Interests

Interests

  • ElectronicsSoftware/Firmware3D-PrintingCADOpen Source HardwareDIY Guitar Pedals/Audio Effects
References

References

  • Available upon request.