Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip...

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Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital of Pittsburgh University of Pittsburgh Senior Design – BioE1161

Transcript of Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip...

Page 1: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Design of a Malignant Hyperthermia Susceptibility

Screening Device

Sara DollLisa KaczmarskiPhilip Magcalas

Department of AnesthesiologyChildren’s Hospital of Pittsburgh

University of PittsburghSenior Design – BioE1161

Page 2: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Overview-The Problem

Malignant Hyperthermia (MH) is a chain reaction event wherein susceptible patients, when administered common gas anesthetics, undergo drastic physiological changes.

• greatly increased body metabolism

• muscle rigidity

• fever up to or beyond 43°C

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

Page 3: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Overview-The Solution

It is hypothesized that MH susceptible muscle, when compared to normal muscle, will be significantly different in compound muscle action potential (CMAP) and force of contraction.

The solution lies in the design of a device that restricts arm movement, while measuring the isometric force produced by the thumb when the ulnar nerve is stimulated. This may then be used to develop a standardized protocol for MHS screening.

Such a device would ultimately be beneficial to:• Anesthesiologists • Patients and their families• The general Population

Page 4: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Project Goals

1. Create a device that meets design requirements

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

can be easily sanitizedcan be transported with ease (lightweight)has minimal assembly or adjustment requirementscan be used with both the right and left handsmaintains the arm at the same height as the OR bed

fastens securely to bed in operating room

securely restrains the patient’s forearm and hand

comfortably accommodates 3 to 5-year-old patients

Page 5: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Device Features

1- Arm board

2- Arm/hand restraints

3 – Force Transducer Mount

4 - Support

Page 6: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Design Options

Materials

Board• Wood

• Metal

• Polymer

Straps• Fabrics

• Polymers

Arm/Hand Restraints• U-shaped cushions

• Adjustable straps

• Top restraint

Force Transducer Mount

Track• Integrate into board

• Attach on edge

Orientation• Left hand only

• Ambidextrous

Range of motion• Fixed

• Planar

• Angular

Support• Moveable cart

• Vises on side of OR bed

• Integrate into existing equipment• Elevator• Recess for armboard

Page 7: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

The Design Process

- Prototypes (3 total)

- Frequent meetings• continuous design feedback and refinement of design requirements from mentors

- Anthropometric data

- Material samples• arm board and straps

- The process of manufacturing• Carrying out reality from concept - importance of details, details, details

Page 8: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

The Evolution of Design

Dec.

Concept Prototype #1

Jan.

Page 9: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

The Evolution of Design (cont’d)

metal

Nylon Velcrostraps

rigid, 1-1/2”polymer

Flexiblepolymer

Jan.

Concept #2

Feb.

Prototype #2

Page 10: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

The Evolution of Design (cont’d)

Prototype #3

Mar.

Page 11: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

The Final Design

3 – Force Transducer Mount

2- Arm/hand restraints x 4

4 - Supportx 3

1- Arm board

Page 12: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

The Final Design (cont’d)

TOP BOTTOM

Page 13: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Benefits of our Design

Arm board ambidextrous

sized for wide range arm/hand sizes

simple construction

Arm restraints adjustable

removable

flexible

single material, single piece

sanitizable

strong (resistance to tear)

Force Transducer Mount translation in two planes

interchangeable (support 2 diff. FT)

ambidextrous

Support integrates with existing equipment

sturdy

separable from arm board

Page 14: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Benefits of our Design

Overall - Simplicity

in design

in assembly

in manufacture

- Satisfies ALL design requirements

Page 15: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Competitive AnalysisCompetitors

• Halothane caffeine contracture testing (muscle biopsy segments)

Our Strengths• Non-invasive• Not necessary to wait for laboratory results• Less expensive• Quick procedure, which may be performed pre-op

Our Weaknesses• Potentially less accurate

- Not testing on actual muscle fiber- Not standardized process

Our device’s strengths outweigh the weaknesses…However

- Contingent upon accuracy of device

- Reliant upon efficiency of data acquisition program, which lies outside the scope of this project

Page 16: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Other Considerations for Design

Manufacturability• Acrylic

• Workable• Cost• Durable

• SolidWorks• Ease of Use• Available• Experience

Human factors• Contextual Inquiry• Device Observation• Design Plan Assessment• Heuristic Evaluation

Page 17: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Class II (moderate risk)• ‘isokinetic testing and evaluation system’ (890.1925)• contact with skin but non-invasive

No Predicate Device

Currently 510(k) and PMA exempt• Investigational device - clinical evaluation required for further

development

• IDE regulation will be required

However in the future, should the decision be made to pursue marketing this device, this will require a Class II PMA device application

Regulatory Concerns

Page 18: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Constraints to Further DevelopmentRegulatory

• Again, no predicate device. Final FDA approval will be complicated

Market• Limited now to Children’s Hospital until a more

precise MH susceptible screening protocol can be established.

Economic Resources• Limited breadth of project funds

Human Resources• Time constraints of all involved

Page 19: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Project Management

Our Goals What we Actually Achieved

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

Force Transducer Calibration• Known force range• Located an amplifier • Preliminary signal processing

Waveform filteringEstablish force-voltage relationship

Build a device that: •Comfortably accommodates 3 to 5 year old patients•Ambidextrous•Fastens securely to OR bed• Can be easily sanitized and transported with little assembly•Allows for accurate measurement of contraction force and clear data interpretation

• Arm Board and Support • Currently in machining

• Overall - accomplished a simple, compact design that satisfies all design requirements

• Straps (Adjustable size)• Assembled

• Force transducer• Grass/Astromed FT03, FT10 obtained• Mounting Device Currently in machining

Device In Pre-Assembly

Page 20: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Project management (cont’d)

December

- Preliminary SolidWorks drawing for armboard, support

- 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

December

- Discussed device requirements with advisors

- Researched materials

February

- Design revisions

- Gathered materials for and built Prototype 2

- Prototype 2 Assessment

- Preliminary SolidWorks drawing

April

- Device machining underway

- Draft final report and presentation

March

- Ordered final materials

- Anthropometric research

- Gathered materials for and built Prototype 3

- Finalized dimensions and SolidWorks Drawings

- Submitted design to machining

January

- Gathered materials for and built Prototype 1

- Ordered force transducers (Grass FT03, FT10)

- Prototype 1 assessment

Projected Schedule Completed Schedule

Page 21: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Project management (cont’d)

Who was responsible what

Sara Doll•Armboard SolidWorks•Strap SolidWorks•Concept SolidWorks•Mentor Meetings•Prototype 3

Lisa Kaczmarski•Material Research•Materials Acquisition•Contact with Suppliers•Prototype 1•Final Product (straps and armboard)

Philip Magcalas•Device Concept Drawings•Anthropometric Research•Force Transducer Mount Solid Works•Prototype 2•Final Product (FT supports)

Page 22: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Acknowledgements

• Dr. Brandom’s Clinical Research Fund• Children’s Hospital of Pittsburgh

• Dr. Barbara Brandom• Dr. Robert Sclabassi• Dr. Andreas Hoyer

• Prof. Mark Gartner• Dr. Mingui Sun• Joe Beuten

• Total Plastics, Inc.

• George Kurzdorfer• University of Pittsburgh

• Department of BioEngineering

Page 23: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Thank you!Questions?

Page 24: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Design Details – Arm Board

H=30cmW=33cm

Page 25: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Design Details - Support

H=9.8cmW=17.5cm

Page 26: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Design Details – Force Trans. Mount

H=4.4cmW=10.2cm

H=7.3cmW=28.1cm

Page 27: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.

Design Details - Straps

large

small

Page 28: Design of a Malignant Hyperthermia Susceptibility Screening Device Sara Doll Lisa Kaczmarski Philip Magcalas Department of Anesthesiology Children’s Hospital.