STATag Prototype Presentation Daniel Tubbs Jason Sadler Chad Hilton December 13, 2004 Brian Easton Latricia Simon James Mayor 1 Societal Problem Defined Hospital staff waste time locating mobile equipment, wasting billions of dollars annually. 35-60%1 of a nurse’s time is wasted on Searching for equipment Clarifying orders Entering redundant information Wasting $58 - $99 billion annually2 December 13, 2004 2 Solution The use of STATags will Reduce man hours searching for needed equipment Increase staff efficiency Increase a nurse’s efficiency at least 10%1 Lower operating costs Save a real $1 for every $4 of efficiency gained3 (reduction of overtime, increased turnaround) Increase job satisfaction3 December 13, 2004 3 STATag Goals Use dead-reckoning to determine current location Use network security Use a self-discovering and self-configuring network Handle large quantities of equipment December 13, 2004 4 STATag Goals (continued) Activate alarms Store historical location and usage data Run without intervention for long periods Battery must last 5-7 years Need calibration only when battery is changed December 13, 2004 5 STATag Limitations STATag will not: Prevent theft Collect or transmit personally identifiable health information (covered under HIPAA) Communicate further than 100 feet between STATags December 13, 2004 6 STATag System ` STATag Web Browser User STATag STATag Network Coordinator DB Server Internal Webserver STATag STATag Database December 13, 2004 7 Web Server / User Interface ` STATag Web Browser User STATag STATag Network Coordinator DB Server Internal Webserver STATag STATag Database December 13, 2004 8 Database ` STATag Web Browser User STATag STATag Network Coordinator DB Server Internal Webserver STATag STATag Database December 13, 2004 9 STATags ` STATag Web Browser User STATag STATag Network Coordinator DB Server Internal Webserver STATag STATag Database December 13, 2004 10 Web Server Open source web server Provides a bridge between the end user and the database Eliminates the need for client software Allows any client with a web browser to connect December 13, 2004 PC Laptop PDA 11 Database Open source relational database collects and stores STATag location information Real-time look-ups History Alarms Inventory Reports December 13, 2004 12 STATag Diagram Battery December 13, 2004 802.15.4 Module Usage Module (In use switch) Microcontoller Movement Detection Module (Accelerometers & Gyroscopes) Flash RAM (1MB) Tamper Detection Module (Tag Removed Switch) 13 STATag Accelerometers and gyroscopes detect orientation and motion Microcontroller calculates current position 802.15.4 module communicates to DB server via mesh network Switches provide state information RAM records position data when unable to communicate with DB server Battery keeps everything running for 5 years December 13, 2004 14 Project Risks – Web Interface Inadequate response time Complexity of use Complexity of administration December 13, 2004 15 Project Risks - Database Database size may grow too fast Database design may be too complicated to use without regular administration Response time may be inadequate for a large number of tags December 13, 2004 16 Project Risks – STATag Interference with hospital monitoring equipment STATag transmits 1% the power of other safe wireless devices Most major hospitals are implementing WiFi Conflicts with other 2.4 GHz networks 802.15.4 has been designed for interoperability 802.15.4 and ZigBee are new standards and therefore there may be unknown issues Hardware issues are being resolved by manufactures Software issues will be correctable by patching December 13, 2004 17 Prototype Goals Build a prototype for each subsystem Demonstrate integration of the subsystems Web server and user interface Database Individual STATag December 13, 2004 18 Prototype Diagram ` Web Browser User Dead Reckoning Module 8 N 11 02 . etw ork DB Server Internal Webserver Simulated Position Data Laptop Live Position Data Database December 13, 2004 19 Prototype vs. Real System Database Web Server User Interface Web Browser Hardware December 13, 2004 Prototype MSSQL IIS 5.1 ASP.NET Any Same PC Real System MySQL Apache Java Any Separate Servers 20 Prototype vs. Real System Accelerometer Microcontroller Wireless Network RAM Gyroscope In-use Switch Tag-removed Switch December 13, 2004 Prototype 2-axis Laptop 802.11b Log File No No No Real System 3-axis On-board 802.15.4 On-board 3-axis Yes Yes 21 Database Accomplishments Each STATag history entry requires 40 bytes Average hospital database size – 67.2 GB (1 year history of 1368 tags updated every 30 seconds) Database design is simple December 13, 2004 22 Database Schema sn_type description PK type_num PK serial_num description FK1 type_num region PK,FK1 PK,FK1 north south east west top bottom history PK PK,FK1 timestamp statag_id pos_x pos_y pos_z in_use December 13, 2004 region_id statag_id id_sn PK statag_id FK2 serial_num removed statag_region PK PK,FK1 region_id statag_id active 23 User Interface / Database Demo December 13, 2004 24 STATag Prototype ADXL202EB-232 2-axis accelerometer evaluation board with serial interface Custom application calculates position data from log file created by ADXL202EB-232 Position data sent to database server via 802.11b network December 13, 2004 25 ADXL202EB-232 December 13, 2004 26 ADXL202 Surface Mount Package December 13, 2004 27 STATag Demo Acceleration (a) Measured by accelerometer Speed (s) sfinal= sinitial + a * time Position (p) pfinal= pinitial + s * time December 13, 2004 28 Issues Encountered Minimum error - 0.0002 g 5-year cumulative error – minimum of 95 miles per axis Location uncertainty Prototype - 9,025 square-miles Production - 860,000 cubic-miles Maximum allowed error - 1.91 x 10-9 g (5 ft. error after 5 years) December 13, 2004 29 Position Uncertainty After 5 Years December 13, 2004 30 Five-year Error vs. Max. Error Cumulative Error (ft) 1000000 100000 10000 504,922 252,461 126,230 63,115 31,558 15,779 7,889 3,945 1,972 1000 986 493 247 123 100 62 31 15 10 8 4 1 09 E53 1. -09 E 05 3. -09 E 10 6. -08 E 22 1. -08 E 44 2. -08 E 88 4. -08 E 77 9. -07 E 95 1. -07 E 91 3. -07 E 81 7. -06 E 56 1. -06 E 13 3. -06 E 25 6. -05 E 25 1. -05 E 50 2. -05 E 00 5. -04 E 00 1. -04 E 00 2. Maximum Allowed Error (g) December 13, 2004 31 Detected Acceleration by Angle 100 90 Detected Acceleration (%) 80 70 60 50 40 30 20 10 0 88 84 80 76 72 68 64 60 56 52 48 44 40 36 32 28 24 20 16 12 8 4 0 Degrees December 13, 2004 32 Final Prototype Diagram ` Web Browser User Dead Reckoning Module DB Server Laptop Internal Webserver Simulated Position Data Database December 13, 2004 33 Options Continue working with Analog Devices to find an accelerometer / software combination that meets our design needs Replace the dead-reckoning functionality with Real-Time Locating Systems (RTLS) components Both options affect only the STATag subsystem and remaining subsystems remain the same December 13, 2004 34 Continue with Dead-Reckoning PRO Costs and profits are well understood Progress already being made CON May not be able to solve issues May require additional manpower or funding December 13, 2004 35 Switch to RTLS PRO Commercial off the shelf product Standardized, multiple vendors Not affected by cumulative error CON Higher wireless transmitting power Increased hospital installation cost Delayed hospital ROI December 13, 2004 36 Recommendations Move forward with database, web server, and user interface development Convert STATag to use RTLS components December 13, 2004 37 Questions? December 13, 2004 38 References & Calculations 1 Cindy Jimmerson, April 7, 2004 2 $166 Billion (Nurse’s Salary and Benefits)4 x 35% = $58 Billion $166 Billion (Nurse’s Salary and Benefits)4 x 60% = $99 Billion 3 Murphy, Mark: Eliminating Wasteful Work in Hospitals Improves Margin, Quality, and Culture December 13, 2004 39 References & Calculations 4 975,9625 Beds x 10 Mobile Medical Devices per bed = 9.76 Million Mobile Medical Devices 5 Hospital Statistics, 2004 edition, American Hospital Association, as reported by the American Hospital Association website December 13, 2004 40