Danniel | Xingyu Hu

PHANES

🦿 Passive Exoskeleton for Sit-to-Stand and Elliptical Mobility

Role: R&D Lead & Biomechanical Engineer
Timeline: 2021–2023
Team: 5 mechanical engineers (initial design by self, later co-developed)

Overview

PHANES is a mobility-enhancing rehabilitation device developed for individuals living with spinal cord injuries (SCI). Combining a sit-to-stand mechanism and a modified elliptical system, PHANES empowers users to transition independently from sitting to standing and engage in guided exercise at home—supporting muscle activation, upright posture, and physical confidence.

Design Objectives

  • Increase access to physical activity for users with SCI through affordable, non-powered design
  • Enable independent postural transitions (sit ↔ stand)
  • Incorporate a modified elliptical trainer to promote upper-lower body coordination
  • Design for accessibility, safety, and manufacturability

Key Features

🔹 Sit-to-Stand Mechanism

  • Hand-powered system designed around the user’s functional upper body strength
  • 5 design iterations focused on dynamic simulation, strength analysis, and DFM/DFA
  • Validated through FEA and user-centered motion analysis

🔹 Elliptical Mechanism

  • Based on a commercial elliptical trainer modified to enable coordinated upper and lower body motion
  • Linkage geometry defined using MATLAB-based biomechanical modeling
  • Push-pull test rig built to validate SCI-friendly use

🔹 Accessibility

  • Custom transfer system integrated to support users with mobility impairments
  • Modular seat and harness design to improve usability and comfort

Technical Tools & Skills Applied

  • Biomechanical Modeling: MATLAB & motion studies to optimize joint coordination
  • Mechanical Design: SolidWorks, iterative CAD modeling, FEA analysis
  • Prototyping & Testing: Push/pull load testing, ergonomic verification
  • Project Management: Team coordination, funding acquisition ($25K R&D fund via pitch competitions)
  • Design for Manufacturing: Produced 26+ engineering drawings across two subsystems, transferred to fabrication partners (AHBM Systems & EMS E3)

IP & Commercialization Note

Core mechanisms and system integration are based on original designs led by the project author and collaborators. Specific load parameters, linkage geometries, and fabrication instructions are withheld from public documentation to preserve future IP and commercialization potential