Smart Bandage Wound Monitoring Through a Connected Smart
Smart Bandage Wound Monitoring Through a Connected Smart Bandage Mike Blouin – Hardware & Embedded Jenna Hatchard – Embedded & Android Jared Cuglietta – Android & Web ECE 492 Group 1– Winter 2016
Motivation • In-home care of patients costs $1000/day • Bandage swapping may interfere with wound healing • Not replacing a bandage when it needs replacing can lead to infection/interference with healing • Optimally timing bandage replacement reduces costs, speeds healing
Solution Design • Goal: Small size representative of real-world solution • Bluetooth-capable TI CC 2640 Microcontroller • Integrated battery management for 110 m. Ah battery • Temperature, humidity, and moisture sensing • Software recognition of “interesting” data points • Android application for reading information from device and relaying • Web application for remote monitoring of patient information
System Architecture Direction of Data Flow
Components • Communications Module • Reusable enclosed module • Bandage Module • FPC Sewn into bandage
32. 39 mm Communications Module Hardware 15. 45 mm
Code Sample – Enumerating BLE Devices protected void on. Create(Bundle saved. Instance. State) { super. on. Create(saved. Instance. State); set. Content. View(R. layout. activity_main); m. Handler = new Handler(); m. Le. Device. List. Adapter = new Le. Device. List. Adapter(); lv = (List. View) find. View. By. Id(R. id. list. View); lv. set. Adapter(m. Le. Device. List. Adapter); scan. Btn = (Button) find. View. By. Id(R. id. scan. Btn); //api 23+ requires permission access to coarse location even for bluetooth //so we have to ask for permissions //first check if the app already has permissions to access if (Context. Compat. check. Self. Permission(this, Manifest. permission. ACCESS_COARSE_LOCATION) != Package. Manager. PERMISSION_GRANTED) { //prompt explanation if (Activity. Compat. should. Show. Request. Permission. Rationale(this, Manifest. permission. ACCESS_COARSE_LOCATION)) { } else { Activity. Compat. request. Permissions(this, new String[]{Manifest. permission. ACCESS_COARSE_LOCATION}, PERMISSION_REQUEST_COARSE_LOCATION); } } // Initializes Bluetooth adapter. final Bluetooth. Manager bluetooth. Manager = (Bluetooth. Manager) get. System. Service(Context. BLUETOOTH_SERVICE); m. Bluetooth. Adapter = bluetooth. Manager. get. Adapter(); // Ensures Bluetooth is available on the device and it is enabled. If not, // displays a dialog requesting user permission to enable Bluetooth. if (m. Bluetooth. Adapter == null || !m. Bluetooth. Adapter. is. Enabled()) { Intent enable. Bt. Intent = new Intent(Bluetooth. Adapter. ACTION_REQUEST_ENABLE); start. Activity. For. Result(enable. Bt. Intent, REQUEST_ENABLE_BT); } scan. Btn. set. On. Click. Listener(new View. On. Click. Listener() { @Override public void on. Click(View v) { Log. i("Button", "Clicked"); scan. Le. Device(true); } }); }
Testing • Hardware • Separate PCBs allow for individual testing of power stages and MCU • TI Launchpad to be used for development of BLE code • Software • Core State Machine can be easily unit tested • Android application will be largely unit tested • End-to-End test including the MCU and java/web apps will be used to test intercommunication.
Application Notes • PCB Review Guidelines • 3. 3 V Buck/Boost Converter • Talk to us if you are interested ASAP
Questions? Wound Monitoring Through a Connected Smart Bandage
Full Schematic
CC 2650 Launchpad • Code compatible with CC 2640 • Contains XDS 110 Debugger • Can program standalone devices
State Diagram for MCU • States: Sleep, Check, Transmit, Initialize, Temporary Error, Permanent Error • Events: • Check Timer Expires, BLE Timer Expires, Data Change, No Bandage Detected
Power Calculations State Seconds/Hour (S) Current Draw (u. A) CHECK_MODE 12 130, 367 TRANSMIT_MODE 10 8, 400 SLEEP_MODE 3588 2. 7 All Modes (Passive Consumption) 3600 133 Power Consumption: 0. 69 m. Ah Battery Life: 157 hours (6. 6 days) This could be optimized by introducing ultra-low power timers such as TI TPL 5110 for 33. 6% more battery life
Moisture Sensing • Goal: Detect surface moisture through resistivity • Grid of conductive material spaced at 1 cm intervals inside bandage • Max current of 0. 3 m. A < minimum threshold of sensation
Price Estimates • • Price Calculations For Smart Bandage Costs
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