Wireless Oximetry. BME 200/300 Design October 15, Client: Dr. Chris Green Advisor: Dr. Amit Nimunkar

Transcription

1 Wireless Oximetry BME 200/300 Design Octber 15, 2010 Client: Dr. Chris Green Advisr: Dr. Amit Nimunkar

2 Overview Pulse Oximetry Mtivatin Requirements Current Devices & Cncepts Pwer Wireless Hardware Next Steps Acknwledgements

3 Pulse Oximeter Nn invasive medical device Measures Oxygen saturatin Pulse

4 Pulse Oximetry Different wavelenghs f light absrbed differently by xygenated hemglbin Red Infrared (IR) Prbe has LEDs and phtdide Transmissin Reflectance

5 Pulse Oximetry Observing peaks in signal yields pulse Bld xygen saturatin Rati f red signal t infrared Lkup table gives number

6 Clinical Applicatins Anesthesia Pst Anesthesia Care Unit ICU Nenatal Transprt Diagnstic Lab

7 Mtivatin Children & babies are indiscriminant f cable Will remve prbe via cable Wuld allw fr a bigger range f mtin Utilize existing hardware Culd als be used fr adults (i.e. exercise studies) Nt main intentin

8 Requirements Device shuld have minimal Cst (under $500.00) Pwer cnsumptin Size Weight (under 70g) Aim: n data lss in ADC/DAC cnversins Shuld have self-cntained pwer supply f at least 5 hurs Must interface with existing hardware

9 Current Devices & Cncepts

10 Cntec Asian based cmpany with multiple ximetry devices that display readings directly n the prbe Sme f these prducts have Bluetth capabilities that allw the data t be transferred t a cmputer surce

11 Nnin Anther ppular ximeter manufacturer Has similar slutins as Cntec but at (~$500 price range) Can cnnect with many Bluetth devices Cell phne PDA, laptp etc. Mdel with wrist attachment (Bluetth) $

12 Current Wireless Oximeters Neither f these cmpanies have a mdular attachment fr an existing wired device

13 Pwer

14 Pwer Needs At least 5 hurs f cntinuus running time At least 5V Minimal weight/size

15 Traditinal Alkaline (AAA) Advantages Mre capacity Inexpensive Disadvantage Lwer vltage Heavier Dispsable ge=ppup_image&pid=299

16 Lithium In Rechargable Advantages Higher vltage Lightweight Reusable Disadvantages Lwer capacity arger/rcr_cmb.jpg Expensive

17 Design matrix General infrmatin regarding the batteries

18 Wireless

19 WiFi Advantages High bandwidth ~100 meter range ~50 Mbps transfer rate Cmputer interfacing Disadvantages Pwer cnsumptin Sftware required Hardware required (adapter, ruter, access pint)

20 Bluetth Advantages License free Lwest cst (~$75) Channel hpping avids interference Lw pwer cnsumptin Disadvantages ~10 meter range ~1 Mbps data transfer rate Security

21 Zigbee Advantages Lwest pwer cnsumptin Ad-Hc netwrk cnfiguratin Fast netwrk cnnectin Disadvantages New technlgy ~10 meter range ~250 kbps transfer rate Highest cst (~$250)

22 Infrared Advantages Lw pwer cnsumptin N sftware Ad-Hc netwrk cnfiguratin Disadvantages Range (requires line f sight) Lw level f security ~20 kbps transfer rate Interference frm ambient light

23 Design Matrix Bluetth WiFi Zigbee Infrared Pwer Cnsumptin (25) Size (15) Prgramming Feasibility (35) Bit Rate (5) Cst (20) Ttal (100)

24 Hardware

25 Schematic - Prbe + Micrcntrller DAC ADC * Wireless LEDs Phtdide Prbe * Methd f data transfer dependent n wireless methd and chip chsen

26 Schematic - Oximeter + Micrcntrller DAC ADC * Wireless Phtdide LEDs Oximeter * Methd f data transfer dependent n wireless methd and chip chsen

27 Cnsideratins Micrcntrller Shuld have bth ADC and DAC f sufficient reslutin Will need t pwer prbe Shuld allw fr In-Circuit Serial Prgramming (ICSP) Given schematics des nt include all necessary cmpnents

28 Cnsideratins Wireless Bth need t be paired Bidirectinal cmmunicatin necessary Pwer Oximeter dngle pwered by ximeter? Prbe dngle will need external pwer surce

29 Next Steps Cntinue testing n pulse ximeter Begin testing Bluetth chips Pick micrcntrller t fit needs Prttype

30 Acknwledgements Dr. Chris Green Cindy Mdie Amit Nimunkar Dennis Bahr

31 References Webster, J. G. ed Design f Pulse Oximeters. New Yrk: Taylr and Francis. Webster, J. G. ed Biinstrumentatin. New Yrk: Jhn Wiley & Sns, Inc. Principles f Pulse Oximetry Technlgy [Online] Clinical Applicatins [Online] In-Circuit Serial Prgramming (ICSP) Guide. Micrchip, Inc. May [Online] System.aspx

32 Questins