RL Raymond Lei

Selected work

Product engineering from prototype to production.

Embedded, medical, and connected-device projects spanning firmware, desktop software, test systems, and manufacturing.

Connected medical device

iPad Device Monitoring

  • Enabled remote monitoring of drill speed and advance rate for a semi-automated orthopedic surgical drill system.
  • Built the firmware in C on a real-time operating system (Micrium), using an embedded TCP/IP stack for connectivity.
  • Developed a C# PC application to monitor the device's runtime status.

Near-field application

iPhone Temperature Reader with RFID Tag

  • Researched and selected components for near-field application requirements, then built proof-of-concept firmware for an iPhone accessory.
  • Programmed RFID devices and built test tools for the RFID reader and tag.

Production manufacturing

Thermo Cycler

  • Developed and refined manufacturing work instructions, including software load and test procedures.
  • Assembled chassis, electronics, interconnects, control boards, and shipping packaging, and trained assembly technicians.
  • Supported in-process high-precision temperature calibration, Hi-Pot testing, and functional test.

Desktop application

Home Use Stimulator for Treatment of Macular Degeneration

  • Built a Windows application in C# to interface with a portable stimulator, using a USB-HID library and a multi-threaded design.
  • Supported development of the software test requirements.

ARM firmware and test

Handheld CO2 Monitor Device

  • Developed firmware on the ARM7 platform using an open-source toolchain.
  • Built an Excel-based tool to plot and analyze test data.
  • Developed a C# Windows application to record test data to CSV files.

Constrained embedded system

Hospital Patient Warming System

  • Root-caused and fixed a firmware defect in C found in units returned from the field.
  • Added a new error-detection feature and led verification, validation, and test report updates, all within a system already at 96% ROM and 94% RAM usage.

DSP and device interfaces

CPAP Device

  • Developed firmware for the device's user interface and component drivers, including LCD, user switch, stepper motor, USB mass storage, RS-232, onboard flash, and real-time clock, on a TI DSP real-time OS.
  • Built a command-line console for system diagnostics and debugging.
  • Developed a C# Windows application, using the open-source ZedGraph library, to plot system test data in real time.