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Project Summary

Project Information

Problem Statement A mechanical model of the respiratory system demonstrates the various components involved in breathing mechanics. This model includes the lungs, diaphragm and rib cage; each is vital to normal human breathing. Accurate representation of the volumes and pressures present in the body are essential to an effective model. The current model used in the BME department is not anatomically accurate; therefore, has limited educational value. This project aims to improve the current “balloon in rigid cylinder” model used in RIT’s Systems Physiology Dynamics and Controls laboratory. The end goal is to prototype a device possessing physiologically relevant lung capacities and flow rates, as well as simulate accurate diaphragm and rib cage movements during various breathing patterns. It is expected to maximize ease of use. A budget of $250 and utilization of PASCO hardware for pressure and flow rate measurement is highly recommended. For preliminary information regarding this project see our Project Readiness Package. Current lung model (click image for demonstration)

Project Name Physiological Lung Model Project Number P16084 Project Family Biomedical Engineering Start Term Spring 2016 End Term Fall 2017 Faculty Guide John Kaemmerlen Primary Customer Dr. Jennifer Bailey Sponsor (financial support) :RIT Biomedical Engineering

Phase Summaries

Problem Definition

In this phase we assessed the deficiencies of the current lung model through discussion with our customer as well as experimentation with the model. From there, we identified key deliverables including engineering requirements, customer requirements, and the ability of our improved model to perform in it’s intended function and environment.

Systems Design

In the system design phase we began to define the overall functions of our model via functional decomposition and systems architecture. This process, along with a preliminary risk assessment and feasibility analysis , guided the selection of a high level design for an improved model. The outcome of this phase included a primary model design, as well as a high-tech option design.

Subsystem Design

This phase featured a more thorough analysis of the major sub-systems in our primary design. Optimal designs for each individual sub-system were assessed and subsequently modified in order to conform to the requirements of the overall system. Additionally, a preliminary bill of materials document was created to ensure design options satisfied budget constraints.

Preliminary Detailed Design

During this phase, a new design for the lung material was formulated and tested. A plan for the ribs was further developed. A bill of materials was presented for two options: a model with ribs or a model without ribs. The team consulted the customer before deciding on the rib inclusive model. The risk management plan was updated to reflect design changes.

Detailed Design

As a result of the comments from the previous phase, it was decided that a half-sized model would be utilized instead of the proper, physiological dimensions. New ideas were explored for the construction of the diaphragm and chest cavity. A more in depth understanding of the mechanics of the overall system, as well as the function of each component was developed. Subsystems were simulated/prototyped, material choices were determined, and preliminary test plans were created. The bill of materials and risks were assessed and updated accordingly.

Build & Test Prep

Test plans for each subsystem as well as the fully constructed system were determined. This phase was also used to update our project plan, order materials, and settle any outstanding issues from MSD 1. The team decided to forgo magnetic movement of the rib subsystem in favor of a mechanical, cable based system.

Subsystem Build & Test

The following subsystems were built in this phase: ribs, lungs and chest. A stand to hold the lung model during use has been partially assembled. In order to address some issues regarding thermoforming and pressure sealing our chest cavity, the design was tweaked and alternate methods of production were considered. Since our rib cage no longer needed to be treated chemically, we were afforded the opportunity to introduce sternum movement along with floating rib movement.

Team Members

Member	Role	Contact
Dakota Bolt	BME - Engineer, Materials Manager	djb7949@rit.edu
Jade Evans	BME - Engineer, Customer Relations	jjr1945@rit.edu
Alice Daniel	ME - Lead Engineer	axd9720@rit.edu
Meaghan Erlewein	BME - Engineer, EDGE Administrator	mae4886@rit.edu

Table of Contents

Content Guidelines:

MSD I & II	MSD I	MSD II
Planning & Execution Project Photos and Videos Imagine RIT	Problem Definition Systems Design Subsystem Design Preliminary Detailed Design Detailed Design	Build & Test Prep Subsystem Build & Test Integrated System Build & Test Integrated System Build & Test with Customer Demo Customer Handoff & Final Project Documentation