Design of a Malignant Hyperthermia Susceptibility

Screening Device

Sara DollLisa KaczmarskiPhilip Magcalas

Department of AnesthesiologyChildren’s Hospital of Pittsburgh

University of PittsburghSenior Design – BioE1160

OverviewMalignant Hyperthermia (MH) is a chain reaction event wherein

susceptible patients, when administered common gas anesthetics, undergo drastic temperature elevation.

There are currently no standard devices or procedures in common practice to screen the general population for this condition.

The solution lies in the design of a device that measures the isometric force produced by the thumb when the ulnar nerve is stimulated.

Such a device would be beneficial to:

• Anesthesiologists

• Patients

• And their families

Project Goals

1. Establish a clear fundamental understanding of the effects of MH on muscle fatigue

2. Create a device design which comfortably accommodates the patient, while allowing for measurement of a solely isometric contraction force

3. Create a device design which would allow accurate measurements and clear methods of interpretation

4. Test and assess the effectiveness of the device in measuring forces within a specific range

5. Complete all of the above on a limited budget

Device Features & Benefits

Arm restraint platform

Firmly restrain patient’s forearm, hand, and thumb in a comfortable manner for all morphological body types

Force sensor

Accurately and safely measure contraction force of thumb

Overall

Maintain simplicity for ease of assembly, use, and data interpretation

Support

Adjustable mounting assembly that can be tightly secured during testing

Proposed Design

Other possible solutions…Arm restraint platform

• Adjustable straps• Adjustable restraint ‘walls’

• Interchangeable polymer thumb ‘molds’• Fixed metal ring with velcro strap

• Cushioned plastic• Laminated wood

Force sensor• Strain gage• Force transducer connected to metal ring

Support• Vises• Bed-mount

Competitors

Our Strengths Our Weaknesses

Compared to Dr. Hoyer’s

Device

•Simple Design

•Friendly User Interface

•Accessible

•Lacking years of research

•No previous clinical testing

•Time constraints

Compared to Caffeine

Halothane Contracture

Test

•Non-invasive

•Less expensive

•Usable for general population

•Potentially less accurate

•No previous clinical testing

•Time constraints

Collaborations

Universitat Wurzburg, Germany • Andreas Hoyer, M.D. • Melanie Veeser, M.D.

Children’s Hospital of Pittsburgh• Dr. Robert Sclabassi, M.D., Ph.D.

Neurologist, Professor in Departments of Neurological Surgery, Psychiatry, Neuroscience, Electrical Engineering, Mechanical Engineering and Bioengineering

• Dr. Barbara Brandom, M.D.Anesthesiologist, Director of North American MH Registry,

Professor of Anesthesiology

Technology

SolidWorks

- Mechanical component design

National Instruments’ LabView

- Circuitry design

Swanson Center for Product Innovation

- Prototypes, Final Product

Assumptions About Resources

• People• Robert J. Sclabassi, M.D., Ph.D.• Barbara Brandom, M.D.• Andreas Hoyer, M.D.• Mingui Sun, Ph.D. & George

Stetten, M.D., Ph.D.

• Software• Labview - B69• SolidWorks - B62

• Locations• Benedum Design Lab - B62• BioE Instrumentation Lab - B69• Children's Hospital of Pittsburgh

• Manufacturing• Swanson Center for Product

Innovation• Pitt Machining Shop

• Product Assistance• Component part companies• SolidWorks instructors

• But most importantly!• Time• Money

Schedule

December

- Preliminary SolidWorks drawing for arm board, support

- Preliminary circuitry design

- Order force transducer (Grass – model FT03)

January

- Gather materials for prototype

- Build initial prototype

February

- Prototype testing

- Design revisions

- Finalize SolidWorks drawing

- Order final materials

March

- Build/Assemble device

April

- Device testing, as time allows

- Draft final report and presentation

1/5

1/30

1/15

3/12

4/5

4/13

4/13

Nov 23 Nov 30 Dec 7 Dec 14 Dec 21 Dec 28 Jan 4 Jan 11 Jan 18 Jan 25 Feb 1 Feb 8 Feb 15 Feb 22 Feb 29 Mar 7 Mar 14 Mar 21 Mar 28 Apr 4 Apr 11 Apr 18Task Name

Detailed Design Stage

Prepare Prelim SolidWorks

Preliminary SolidWorks drawing

Research circuitry requirements

Preliminary Circuit schematic

Prototype

Obtain materials

Assemble/build

Prototype

Prototype testing

Design Revisions

Finalize SolidWorks drawing

Final Product

Obtain materials

Build/Assemble

Final device

Final Device testing

Testing report

Presentation

Prepare Presentation

Final Slide Presentation

Report

Prepare Report

Final Project Report

Who will be accountable for what

Group Member

Milestone

Sara - Prototype

- Component manufacturer research

- Final SolidWorks drawing

Phil - Preliminary device schematic

- Final Device Testing/Calibration report

- Final product

Lisa - Preliminary SolidWorks drawing

- Prototype Testing Report

- Final product

Current Status

• General MH research• Initial project meetings with mentor• Project planning/development

- Objective Tree- Function-Means Analysis- Human Factors testing plan- Goals, schedule, and milestones defined (Gantt

chart)- Device specifications defined- Preliminary Design Schematic

• Observation of Dr. Hoyer’s device in use

Acknowledgements

• Robert J. Sclabassi, M.D., Ph.D.

• Barbara Brandom, M.D.

• Andreas Hoyer, M.D.

• This is MH: =-(

• This is MH with our device: =)

…Any Questions?