TEAM ADVSIOR: Mitch Tyler, MS PE Department of Biomedical Engineering

1. TEAM MEMBERS:Miguel Benson, Erik Bieging, Ross Gerber, Aman Ghotra, Abdikarim MahamudDepartment of Biomedical Engineering TEAM ADVSIOR: Mitch Tyler, MS PE Department of Biomedical Engineering TEAM CLIENT: Tom Brazelton, MD, MPH Department of Pediatrics UW-Madison Hospital and Clinics

2. Abstract We propose a physical prototype of a gurney-compatible- child seat for transporting children in ambulances. Current seats do not recline; Emergency Medical Technicians (EMTs) must unstrap the child out of seat and remove the seat off the gurney to lay the child flat on the gurney for specific medical treatments. However, this procedure takes up valuable time (~3 minutes) and protracts the time it takes to reach the hospital. As a result, our prototype reclines, and eliminates the need to remove the seat off the gurney to lay the child flat on the gurney. Also, our prototype supports children (1-10 years old) of various anatomical features unlike current ambulatory child seats. Initial testing of four subjects (1-10 year old) have given promising results but more testing needs to be done to assess prototype’s mechanical and safety constraints. Also, we need to seek lighter yet robust material to fabricate future design of the child seat.

3. Background • An estimated 5000 ambulance crashes annually [1] • Safest to transport children sitting up(<30 kg) in child seat attached to gurney in an ambulance [2] • For specific medical conditions, EMTs must unstrap child out of seat and remove the seat off the gurney to lay the child flat on the gurney [3]

4. Background/Motivation • Problems with Current Design: • Seat does not recline • Time consuming (~3 mins) because must remove the seat off gurney to lay child flat • Seat is bulky • Do not always carry seats in ambulances • Children more prone to injury

5. Problem Statement Develop a safe and compact child seat for transporting children (6-30 kg) in ambulances that allows Emergency Medical Technicians (EMTs) to recline the child in the seat from the sitting position to the lying position when strapped onto a stretcher.

6. Design Constraints The Child Seat: 1. Must be compatible with current stretchers; 2. Must secure a child (up to 10 year old) -Mass: 6-30 kg -Shoulder width:12.9-30.8 cm, -Hip to shoulder height: 20-44 cm [4]; 3. Must not restrict EMT’s ability to care for the child; 4. Must be cost-efficient and user-friendly; 5. Must be collapsible; 6. Must recline from 120-180 degrees; 7. Must be easily sterilized.

7. Overview of the Design • We have incorporated four unique features that make the child seat more conducive to ambulance transportation: • Recline Lock • Sliding Strap • Back Rest • Leg Support Overview of Design Concept

8. Figure A: Design Concept Figure B: Prototype Model Figure C: Prototype Model Recline Lock Mechanism • Function: • Reclines the seat • Mechanism: • Similar to a hinge joint • 2 plates joined at center rotate freely about the joint • 1 plate permanently fixed to the seat while the other is attached to the back rest on a rail mechanism • Lock in position with pin • Materials: • Wood and Screws

9. Figure D: Design Concept Figure E: Prototype Design Figure F: Prototype Design Sliding Strap Anchor • Function: • Used to adjust straps • Mechanism: • Latch secures slide in place • Over-center design allows for free hands • Deformable rubber disk for latch support • Materials: • Wood, Screws, Nails, Plastic

10. Figure G: Design Concept Figure H: Prototype Design Back Rest Track • Function: • Anchors back of seat to stretcher • Allows seat and stretcher to be reclined simultaneously • Mechanism: • Beam tracks on the back rest slide into groves in anchored back • Anchored back is strapped firmly to stretcher • Allows back rest to move relative to the stretcher while reclining • Materials: • Wood, PVC piping, screws

11. Leg Support • Function: • Elevates patient’s legs if necessary • Mechanism: • Slides out from beneath base of seat • Supported metal rails fit into base of seat • Materials: • Wood, railing Figure I: Design Concept Figure J: Prototype Design

12. Materials and Cost

13. Tested our prototype on four subjects from the following age groups: 1 year old 4 year old 6 year old 10 year old Subject Testing Figure K: 1 year old subject in upright position Figure L: 1 year old subject in laying position

14. Subject Testing Results: All 4 subjects fit well in seat Easy to adjust seat with subjects in it Difficult for one operator to adjust seat and straps simultaneously Testing (cont.) Figure M: 6 year old subject in upright position Figure N: 6 year old subject in laying position

15. Future Considerations

16. Acknowledgements:We would like to thank Dr. Tom Brazelton and his colleagues, and Biomedical Engineering Department for providing us an opportunity to work on this project. Also, we would like to thank our advisor, Mitch Tyler, for providing us feedback and pointing us in the right direction. References: [1] Safe Ride News. http://www.saferidenews.com/html/Spec_Amb.html [2] Detroit News. http://www.detnews.com/2003/specialreport/0301/27/a11-68893.htm [3] Brazelton, T. University of Wisconsin Hospital and Clinics. Interview. [4] Physical Characteristics of Children. http://www.itl.nist.gov/iaui/ovrt/projects/anthrokids/child.html

17. AMBULATORY

18. CHILD SAFET

19. Y SEAT