1. Detection of Patient Falls Using Three-Axis Accelerometer Umer Jamshaid Tyler Quarles Parampal Randhawa Martha Serna Matthew Treinish March 15, 2011 School of Electrical and Computer Engineering

2. 2 Project Motivation Broken Hipsters Monitoring System (BHMS) –What: Creation of automated fall detection system –Why: Large number of fall related injuries –Who: Residents at Assisted Living Centers –Cost: $59 per unit

3. 3 Goals Creation of Fall Detector Small enough to wear Low cost Low power Detects different falls Development of Control Box Detect resident in bed with pressure sensors Send alert signal to caretaker’s station

4. 4 Competition Push-to-Call emergency pendant available online Some problems: –Requires patients to remember they are wearing a pendant –Does not alarm staff unless button is pressed Patient alertness questionable High cost ($99.95 + $24.95/month)

5. 5 Previous Senior Design Work Use of semi-active RFID tag on patient, coupled with Antenna and Activator on floor –1 foot detection range from floor –Small area covered by Antenna –1 Watt Activator power

6. 6 BHMS Design Overview PIC18 Microprocessor Pressure Pad Red LED Three-Axis Accelerometer Xbee Module PIC18 Microprocessor Orientation Data Xbee Module Fall Detector Control Box Wireless Communication Pressure Data Alert Signal

7. 7 Fall Detector Placement Issue Original design proposal for belt-mounted Fall Detector –Able to detect hip orientation –Easily mounted on belt –Unobtrusive location Fall Detector mounted on an elastic band on leg is a better position: –Easier to detect orientation of patient –Patient injury less likely

8. 8 Modifying Fall Detection Algorithm Fall Detector microprocessor determines if fall has occurred Problem: fall detection algorithm based on orientation may be unable to detect specific types of falls Alternative: detect falls using patient acceleration –Speed of fall does not affect accuracy

9. 9 System Expandability Need to account for chairs and toilet seat in resident’s room to avoid false positives BHMS easily expandable due to modular design Pressure strips can be added to the system at minimal additional cost ZigBee protocol can accommodate multiple wireless modules as a single network

10. 10 Potential Room Layout Resident with Fall Detector Control Box Pressure strip

11. 11 Fall Detection Algorithm

12. 12 Project Schedule (03/01) - Design schematics for Fall Detector & Control Box (03/11) - Build prototypes (03/18) - Test & program microcontrollers (04/15) - Optimize Fall Detector algorithm (04/29) - Final project presentation

13. 13 Cost of Materials MaterialsPrice Triple Axis Accelerometer$ 14.95 Microcontrollers$ 12.20 XBee Wireless Modules$ 84.00 Computer and Monitor$ 500.00 Wires/Cables$ 8.00 Software Development environment$ 690.00 Miscellaneous materials$ 8.88 TOTAL COST$ 1,318.03

14. 14 Labor Cost Analysis TASKSTOTAL HOURS SALARY PER HOUR TOTAL COST PER TASK Lecture/Group meetings 90$30.00$2,700.00 Research90$30.00$2,700.00 Equipment Setup30$30.00$900.00 Software Programming 180$30.00$5,400.00 Debugging100$30.00$3,000.00 Product Testing100$30.00$3,000.00 Demos/Preparation40$30.00$1,200.00 TOTAL HOURS630TOTAL LABOR$18,900.00

15. 15 Total Cost Analysis Cost of Materials: $1,318.03 Cost of Labor: $18,900.00 –Cost of labor is based on 5 entry level engineers Prototyping first product will be expensive Mass production will lower the cost of product. –Final cost after 1000 units sold: $ 59.00

16. 16 Potential Future Work Commercializing BHMS Implement touch screen GUI at caretaker station Add remote access to caretaker station Target hospital and domestic markets

17. 17 Questions One in three people over 65 fall each year, and more than 300,000 hip fractures occur each year because of falls.