Frederico Gutierrez, Mitul Saha

1
Project Plan Presentation

• Frederico Gutierrez, Mitul Saha
• Yong Song and Anna Timbie
• Guidant mentors David Wolf-Bloom, Stephanie
  Szobota
• Stanford mentors Dr. Charles Taylor, Chris
  Elkins
• February 10, 2003

2
Guidant Corporation, Vascular Innovations

• Guidant is a leader in the design and
  development of cardiovascular medical products

3
Motivation

• The development of medical devices is limited by
  the ability of designers to evaluate them before
  human use.

4
Preclinical Test Methods

• Animal studies
• Expensive
• Unfeasible for high-volume
• Ethical considerations
• Simple plastic models
• Cannot replicate
• in vivo conditions
• Human disease state

5
Synthetic Arterial Model

• Simplified human knee to neck anatomy
• Tissue simulating materials
• Perfused with water or blood from pump

6
SAM

• Benefits
• Fluorcompatible
• Modular, plug-n-play
• Portable
• Limitations
• Static flow (roller pump)
• Static heart
• No respiratory movement

7
Project Goals

• To improve the clinical realism of the Guidant
  SAM by incorporating new design features
• Pulsatile flow through the vasculature
• Coronary Artery and Heart Wall Motion
• Respiratory Motion
• Provide Guidant with a tool for product testing
  and physician training

8
Project Scope

• Heart wall motion and pulsatile flow need not be
  coupled
• Anatomical realism of internal heart structure
  not necessary
• Flow rate and pressure within 10 of published
  values

9
Deliverables

• System for regulation of pulsatile flow from
  Harvard Pump through arterial model
• Prototype of mechanism to produce heart wall
  motion
• System for synchronization of heart beat and
  pulsatile flow
• Prototype of mechanism to produce diaphragm
  motion

10
Benchmarking

• Vascular Models
• Consist of Rigid Elements
• No Plug-n-Play Abilities
• Does Not Incorporate Pulsatile Flow

11
Benchmarking

• Beating Heart Models
• The Chamberlain Group
• Training model for beating heart surgery
• Electrically powered
• Uses Pneumatic Coils to Create Motion
• Suturable Exterior Skin
• Not Fluorocompatible

12
Benchmarking

• Mechanical Left A/V model
• Provides realistic flow and pressures of the left
  A/V
• Can be used to calibrate flow for mechanical
  hearts
• Not anatomically realistic

13
Related Technology

• Harvard Pump
• Generates Pulsatile Flow
• Adjustable Flow Rates and Stroke Volume
• Physiologically Accurate Motion

14
Related Technology

• Flexible Molding
• Casting Polyurethane and Silicone Materials
• Relatively low prototyping cost
• Materials range from Hardness of 10-95 (Shore A)
• Flexibility of up to 1000 original size

15
Critical Design Requirements

• Functional

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Critical Design Requirements

• Functional
• Pulsatile flow through the
• vasculature

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Critical Design Requirements

• Functional
• Pulsatile flow through the
• vasculature
• Realistic flow rate and pressure in the major
  arteries

18
Critical Design Requirements

• Functional
• Pulsatile flow through the
• vasculature
• Realistic flow rate and pressure in the major
  arteries
• Heart wall motion

19
Critical Design Requirements

• Functional
• Pulsatile flow through the
• vasculature
• Realistic flow rate and pressure in the major
  arteries
• Heart wall motion
• Synchronization of
• Pulsatile flow and
• Heart wall motion

20
Critical Design Requirements

• Physical
• Fluoro-compatible
• Approximate size and shape of human heart
• Interface with aortic tree and coronary arteries

21
Critical Design Requirements

• Physical
• Fluoro-compatible
• Approximate size and shape of human heart
• Interface with aortic tree and coronary arteries

22
Critical Design Requirements

• Physical
• Fluoro-compatible
• Approximate size and shape of human heart
• Interface with aortic tree and coronary arteries

23
Critical Design Requirements

• Physical
• Fluoro-compatible
• Approximate size and shape of human heart
• Interface with aortic tree and coronary arteries

24
Desirables

• Diaphragm movement
• Adjustable heart rate (70-120 bpm)
• Adjustable vessel pressure
• Easy plug-n-play
• Simulation of cardiovascular disease

25
Expected Difficulties

• Achieving accurate pressure and flow through
  entire model
• Molding of flexible heart
• Leakage due to material incompatibilities
• Air trapped in model
• System integration and controls

26
Timeline (Winter)

• 2/2 2/21 Design Beating Heart
  
• 2/10 2/19 Analytical Flow Model
• 2/10 2/19 Design Lab-View System
• 2/28 tbd Test and Tune Flow Model
• 2/19 3/1 Heart Critical Function Prototyping
• 3/1 Select Heart Design
• 3/10 3/14 Final Presentation Report

27
Timeline (Spring)

• Beating Heart Prototyping
• Diaphragm Motion Design and Prototyping
• Total System Integration and Testing
• Integrate Into SAM
• Final System Testing
• Final Presentation Report

28
Individual Responsibilities

• Eric ? Flow Modeling, Material Research,
• Molding Process
• Anna ? Flow Circuit Modeling, Flow Tuning
• Mitul ? Data Acquisition and Control Systems
• Song ? Harvard Pump Modification, Prototyping
• Full Team ? Background Research
• Benchmarking
• Brainstorming
• Prototyping
• Testing

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ITS A GREAT TIME TO BE ALIVE

• Questions?