Ergonomic CAD Design for Medical Breathalyzer

CAD Design Engineer for Raspberry Pi-Based Breathalyzer Device (Urgent ) Project Overview OraLens Healthcare is developing an innovative portable breathalyzer device for healthcare applications and seeks an experienced CAD design engineer to create a professional, ergonomic enclosure that integrates multiple electronic components into a cohesive, user-friendly medical device. This project represents a critical step in transitioning from breadboard prototype to a production-ready handheld device. As a healthcare technology company specializing in diagnostic solutions, we require a design that meets both functional engineering requirements and medical-grade aesthetic standards. The successful candidate will work directly with our CTO and engineering team to ensure the design meets our technical specifications while maintaining manufacturability and user experience standards. Component Integration Requirements The enclosure must precisely integrate the following specified components, with datasheets and detailed specifications provided upon project commencement: Core Electronics: Raspberry Pi Zero 2 W: Primary computing unit requiring secure mounting with screw bosses, thermal management considerations, and optional SD card access Seeed Studio LiPo Rider Plus: Power management board necessitating precise cutouts for USB-C charging port and USB-A output, with consideration for the module's height profile 1500mAh PCM Protected Micro Li-Po Battery: Dedicated battery compartment with strain relief and secure retention mechanism 5MP Raspberry Pi Camera Module: Critical alignment requirements with rigid mounting for consistent focal distance and optical path Two Push Buttons: User interface elements requiring ergonomic placement for intuitive thumb or index finger operation A Gas sensor: SC05-H₂S Critical Gas Sensing System - SC05-H₂S Sensor: Sensor Specifications (Multiple Variants Exist): The design must accommodate SC05-H₂S sensor variants with flexible mounting system: Potential Dimensions: 20mm diameter × 16.5mm height OR 24mm × 20mm × 16mm rectangular Interface Options: Analog output (requiring ADS1115 ADC module) OR digital UART/I2C Power Requirements: 5-50mA depending on variant Environmental Sensitivity: Highly sensitive to direct moisture exposure and airflow velocity Critical Design Note: Exact sensor specifications must be verified before final design, requiring modular mounting approach to accommodate variants. Dual-Chamber Architecture Requirements Chamber A: Gas Sampling System (Isolated "Wet Zone") Airflow Path Engineering: Mouthpiece Interface: Bayonet or snap-fit mount for disposable mouthpieces (8-10mm internal diameter) Flow Conditioning: Expansion chamber reducing breath velocity before sensor exposure Sensor Positioning: Side-mounted perpendicular to main airflow (prevents direct impingement damage) Chamber Volume: 35-45mL optimized for response time and sample adequacy Dead Volume: Minimized to <5mL between mouthpiece and sensor for rapid response Moisture Management System (Critical for Sensor Longevity): Primary Condensation Trap: Gravity-based separator immediately downstream of mouthpiece Collection Capacity: 2-3mL condensate collection with drainage system Sensor Protection: Mounting provision for 0.2μm hydrophobic PTFE membrane Drainage Path: External weep system preventing moisture accumulation Sealing: Complete isolation from electronics bay with sealed cable feedthroughs Chamber B: Electronics Bay (Isolated "Dry Zone") Component Layout Strategy: Bottom Layer: 1500mAh battery with secure retention and foam padding Middle Layer: Raspberry Pi Zero 2 W with thermal management (passive ventilation required) Interface Layer: Power management board and optional ADC module Cable Management: Internal routing for camera ribbon cable and sensor wiring Thermal Management Requirements: CPU Cooling: Ventilation slots positioned above Raspberry Pi CPU location Air Circulation: Minimum 2mm clearance for convection cooling Heat Isolation: Prevent thermal influence on sensor chamber temperature User Interface and Ergonomics Form Factor Specifications: Target Dimensions: 96mm × 52mm × 38mm Weight Target: Under 220 grams fully assembled for comfortable single-handed operation Ergonomic Design: Contoured surfaces with non-slip texture provisions Control Interface: 2 Push Buttons: to operate capturing pictures and to get breathelyzer readings Toggle switch with Seeed Studio LiPo Rider Plus : Power on and off the device Status Indicators: LED visibility through light pipes or transparent windows Charging Port: USB-C access positioned for convenient charging Critical Engineering Considerations: Thermal Management: The Raspberry Pi Zero 2 W generates significant heat during computer vision processing tasks, requiring passive ventilation near the CPU location Cable Management: The camera's ribbon cable is delicate and has limited flexibility - the design must ensure the distance between the Pi's CSI port and camera mounting point doesn't require sharp cable folds Component Height Constraints: The LiPo Rider Plus's USB-A port will likely dictate the minimum device thickness Design Requirements and Scope Functional Requirements: Ergonomic Design: Comfortable single-handed operation with intuitive button placement and secure grip design Breath Sampling Interface: Integrated mouthpiece design with internal airflow channel from user interface to sensor region, minimizing dead volume and preventing condensation damage to electronics Camera Integration: Proper positioning with clear optical path for facial verification during breath sampling, including protection via recessed opening or transparent cover Assembly Design: Two-part shell construction (top/bottom) using standard metric hardware (M2.5 or M3 screws) or engineered snap-fits for ease of assembly and maintenance Cable Routing: Internal pathways and clips to manage interconnecting cables, preventing pinching, rattling, or component interference Physical and Aesthetic Requirements: Form Factor: Handheld device similar in size to digital medical instruments, targeting under 220 grams fully assembled Professional Appearance: Medical-grade aesthetic with clean, modern industrial design language suitable for healthcare environments Accessibility: Clear access to charging port, button actuation, and any status LED indicators Finalized CAD files in multiple formats: Native CAD files (fully parametric) STEP/IGES files for manufacturing compatibility STL files optimized for 3D printing Complete 2D engineering drawings with dimensions, tolerances, and assembly instructions Exploded view assembly drawings showing component placement and assembly sequence Bill of Materials (BOM) with hardware specifications Minimum 5 high-quality photorealistic renderings from multiple angles Design rationale document explaining key design decisions and engineering considerations Required Qualifications and Skills Essential Requirements: Minimum 3 years of professional CAD design experience with consumer electronics or medical device enclosures Expert proficiency in professional parametric CAD software (SolidWorks, Fusion 360, Creo, or equivalent) Demonstrated understanding of Design for Manufacturing (DFM) and Design for Assembly (DFA) principles Portfolio showcasing relevant handheld device designs, particularly those involving embedded systems Experience with Raspberry Pi or similar single-board computer integration Preferred Qualifications: Previous experience designing medical devices or healthcare products Understanding of regulatory considerations for medical device housings Knowledge of thermal management in portable electronic devices Familiarity with breath-sampling devices or diagnostic equipment design Experience with both 3D printing and injection molding processes Professional Attributes: Strong attention to detail and dimensional accuracy Excellent communication skills for iterative design discussions Ability to work independently while collaborating effectively with engineering team Responsive to technical feedback and willing to iterate based on engineering requirements Understanding of ergonomics and human factors in medical device applications Application Requirements To apply, please submit the following materials: Portfolio: Examples of previous enclosure designs, particularly for electronic devices, medical equipment, or IoT products Technical Approach: Brief description (300-400 words) of your proposed design methodology and approach to this specific project Timeline and Pricing: Detailed project timeline with milestones and comprehensive pricing breakdown (fixed project fee preferred) Software Specification: Identify which CAD software you will use for this project Clarifying Questions: Any questions about project scope, component specifications, or technical requirements Project Terms and Communication Communication Expectations: Regular progress updates (minimum twice weekly) with availability for video conferences to discuss design progress and provide technical feedback. We maintain an collaborative approach with our engineering team available for technical consultations throughout the project. Intellectual Property: All designs, files, and documentation become the exclusive property of OraLens Healthcare upon project completion and final payment. Future Opportunities: This project represents potential for ongoing collaboration as our product line evolves through subsequent iterations and additional healthcare technology products. To Apply: Please submit your complete proposal with all required materials. This project offers the opportunity to contribute to meaningful healthcare technology innovation while working with an experienced engineering team in the medical technology sector.

ID do Projeto: 40140374