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 Woman had wounds for 10 years, for 2 years received home care, total cost estimate around $1000/day. Over two years cost ~$730,000. With aid of the smart bandage, if only have to do homecare every other day for the 2 years, then the cost would be ~$367282.62 which saves a total of ~$362717.38 (calculations in appendix)
Solution Design Goal: Small size representative of real-world solution Bluetooth-capable TI CC2640 Microcontroller Integrated battery management for 110mAh 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 Bandage Module Reusable enclosed module Bandage Module FPC Sewn into bandage
Communications Module Hardware Battery image source: https://www.sparkfun.com/products/13112 Battery Dimensions: 5.7x12x28mm Stats: 32 Packages 83 SMDs 8 fine pitch
Code Sample – Enumerating BLE Devices protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mHandler = new Handler(); mLeDeviceListAdapter = new LeDeviceListAdapter(); lv = (ListView) findViewById(R.id.listView); lv.setAdapter(mLeDeviceListAdapter); scanBtn = (Button) findViewById(R.id.scanBtn); //api23+ 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 (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) { //prompt explanation if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.ACCESS_COARSE_LOCATION)) { } else { ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, PERMISSION_REQUEST_COARSE_LOCATION); } } // Initializes Bluetooth adapter. final BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE); mBluetoothAdapter = bluetoothManager.getAdapter(); // Ensures Bluetooth is available on the device and it is enabled. If not, // displays a dialog requesting user permission to enable Bluetooth. if (mBluetoothAdapter == null || !mBluetoothAdapter.isEnabled()) { Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE); startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT); } scanBtn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Log.i("Button","Clicked"); scanLeDevice(true); } }); }
Testing Hardware Software 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. Testing is all about isolation of problems. Goal with hardware is to have easily accessible paths for isolating various components/functions.
Application Notes PCB Review Guidelines 3.3V Buck/Boost Converter Talk to us if you are interested ASAP
Questions? Wound Monitoring Through a Connected Smart Bandage
Full Schematic
CC2650 Launchpad Code compatible with CC2640 Contains XDS110 Debugger Can program standalone devices
State Diagram for MCU States: Events: 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 (uA) CHECK_MODE 12 130,367 TRANSMIT_MODE 10 8,400 SLEEP_MODE 3588 2.7 All Modes (Passive Consumption) 3600 133 Power Consumption: 0.69mAh Battery Life: 157 hours (6.6 days) This could be optimized by introducing ultra-low power timers such as TI TPL5110 for 33.6% more battery life Would reduce the all mode passive consumption + SLEEP_MODE to ~40nA.
Moisture Sensing Goal: Detect surface moisture through resistivity Grid of conductive material spaced at 1cm intervals inside bandage Max current of 0.3mA < minimum threshold of sensation
Price Estimates Approximate cost for 2 year homecare without the Smart bandage 1000 365 2 = $𝟕𝟑𝟎,𝟎𝟎𝟎 Approximate cost for 2 year period with smart bandage 1000+6.2 365 = $𝟑𝟔𝟕,𝟐𝟖𝟐.𝟔𝟐 Overall Savings 730000− 3672.62=$𝟑𝟔𝟐,𝟕𝟏𝟕.𝟑𝟖 Price Calculations For Smart Bandage Costs