ANTS Anesthesiology Neuromuscular Monitoring System #25

Group Information Greg Angelotti (EE) Otto Cruz (CpE) Kristin “Zaza” Soriano (CpE/EE) Sponsor: Dr. Thomas Looke (Anesthesiologist/EE)

Current Methodology Administer Neuromuscular Blocking Agents (NMBA) –Blocks Acetylcholine (ACh) Trivial neuromuscular stimulating Subjective muscle response monitoring (if any at all) Pen and paper record keeping

Current Methodology *Courtesy of nursingcrib.com

Current Methodology StimulateMonitorLaments Ulnar NerveAdductor PollicisThumb Posterior Tibial NerveFlexor Hallucis BrevisFoot Facial NerveCorrugator SupercilliEyebrow* Facial NerveOrbicularis OcculiEyelid* * Research shows not as reliable as the first two sites

Objectives To safely stimulate targeted sites To effectively obtain patient signals To accurately record patient feedback To create a more organized environment

Requirements Must consist of safe modular subsystems Must obtain objective quantitative muscular responses Must produce individual patient feedback and logging Must reduce operating room clutter

Overall Block Diagram

Specifications Shocking Device Battery3.7 Volt 2200 mAh Lithium Ion Polymer Up Time6 Hours Idle Time3 Days Input Voltage3.7 Volts Output CurrentVariable 0 to 70 mA Output PulseSquare Wave Pulse 200us Duration Train of FourSingle Set of 4 Pulses Per 2 Seconds Tetanus100 Hz (100 Pulses Per Second) Twitch1 Pulse Per Second Dimensions30 x 40 x 10 mm

Shocking Device

MCU & Bluetooth PartCC2540BLE112 ManufacturerTexas InstrumentsBluegiga Dimensions6.5 x 6.5 x 1 mm MCU8051 Memory128/256 Kb TransceiverBluetooth 4.0 Receiver19.6 mA Transmitter24.0 mA27.0 mA Power Consumption2 to 3.6 volts Cost (Dev. Kit)$289.75$350.00

Shocking Device

Current Control PWM to produce the 200us square wave form. 10 Bit Serial SPI Dual Output DAC to control current output. 2^10 taps (1024) with a 10 bit DAC Issues deciding between Digital Potentiometer (voltage) and DAC (voltage & current).

Current Op amp Current input varies between 0 to 150 uA. Current output 0 to 750 mA. Availability and price is the reason for this part.

DC to DC Converter Optional part Input 3.1 to 75 volts Frequency Synchronization

Shocking Device

Negative Feedback DC Converter to ADC port on MCU Digital Integral controller to regulate the stimulation current. Using the formula above will allow us to control the stimulators output.

Shocking Device

Power Supply Voltage buck/boost regulator dual output 3.7 volts supplies processor & 5 volts supplies DAC Boost Voltage regulator supplies op amp at 8 volts The power supply is a 3.7 volt 2200 mAh lithium ion polymer.

Overall Block Diagram

Specifications Sensor Device Dimensions30 x 40 x 10 mm Battery5 V Up Time6 Hours Idle Time3 Days Data TransmissionBluetooth 4.0 Wireless Range<50 meters Data Resolution12 bit Action Potential Detection mV Pressure Detection lbs Flex Sensor Angle degrees

Sensor Device

Surface EMG Pick targeted sites Prepare the site Place Ag/Cl reference electrodes Ring Electrodes [preferred] Disc Electrodes [<10 mm] Ready to read patient action potentials 0-6 mV [Typical]

sEMG Preconditioning

Sensor Device

Tactile Pressure Sensor SensorFSR 400A301 ManufacturerSparkfun ElectronicsTekscan Sensing Area0.3”0.375” Force Range0-10 lbs0-25 lbs Response Time1-2 usec<5 usec Price5.95 USD16.25 USD Image

Pressure Sensor Conditioning Standard Resistance from sensor (FSR): –Appr. 1 MOhm VREF should be negative –Appr. -5 Volts The smaller RG is the more sensitive the sensor becomes Inverting Amplifier Vout = (Vref)*(RG/Sensor)

Sensor Device

Flexible Potentiometer Sensor SensorFS7548SoftSpot ManufacturerSpectra Symbol Length114 mm100 mm Thickness.48 mm.51 mm Resistance Range1 KOhm – 100 KOhm1 KOhm – 10 KOhm Price14.95 USD12.95 USD Image

Bend Sensor Conditioning Standard Resistance from sensor (FSR): –Appr. 10 KOhm VREF should be negative –Appr. -5 Volts The more the sensor bends the more the greater the impedance Inverting Amplifier Vout = (Vref)*(RG/Sensor)

Sensor Device

Power Distribution

Overall Block Diagram

Specifications Tablet Device Dimensions10” x 6 ¾” x 2” Battery4000 mAh, 5V Up Time4 Hours Idle Time8 Hours Data TransmissionBluetooth 4.0 Wireless Range<50 meters Screen Resolution1024 x 600 pixels

Main Device

Touchscreen ParameterSpecification Diagonal Size10.1” Aspect Ratio16:9 Resolution4096 x 4096 Accuracy±1.5 % Transmissivity90 % Active Current6 mA Sleep Current94 µA Digital Power Supply3.3 V DD

Touchscreen Controller Custom I 2 C Voltage-level Shifter Pandaboard ES J6 Expansion Header GND SCL SDA VIO

Main Device

TFT-LCD ParameterSpecification Diagonal Size10.1” Frame Rate60 Hz Resolution1024 x 600 pixels Maximum Power Consumption2.6 W Maximum Backlight Power Consumption1.5 W Thickness0.5 mm Digital Power Supply3.3 V DD IDD Current240 mA

LCD Controller LED Backlight Control I/O 30-pin LVDS Connection LCD I/O Pandaboard ES J3/J4

Main Device

Pandboard ES Features Dual Core ARM Cortex A9 (1.2 GHz) Graphics support (ex: OpenGL) LCD expansion header 1 GB low power DDR2 RAM SD card slot General I 2 C expansion headers b/g/n (WiFi) Bluetooth 4.0 Awesome support community!

Pandaboard ES

Main Device

Tablet Power 6 volts mAh 23 x 99 x 71 mm $15-17

Tablet Software Ubuntu C++ qT

Monitoring Screen

Bill of Materials (Tablet) ItemCost 10.1” TouchScreenFree 10.1” TFT-LCD Display$41.89 LVDS Cable$9.88 LCD Controller Expansion$57.18 Pandaboard ES$ Power adapter (dev)$ mm pitch male pin headers$6.46 USB to RS-232 adapter (dev)$7.00 HDMI to DVI cable (dev)$4.56 8Gb SD cardFree

Bill of Materials (Sensors) ItemCost sEMG ElectrodesFREE Pressure Sensor$5.95 Bend Sensor$12.95 Rotary Potentiometer$1.75 Low Noise Op Amp x 3$2.32 Differential Amp$10.25 CC2450 Developers Kit (2 Modules)$ PCB Cost (Expected)$70.00 Misc (Resistors,Capacitors,Diodes,etc)Free

Bill of Materials (Total) DeviceTotal Cost Main Device (Tablet)$ Sensor Device$ Shocking Device$70 Running Total$787.41

Progress

Coming Soon? Finish prototyping Finalize sensor PCB schematic for printing Program microcontrollers Sync Bluetooth devices Integrate tablet parts Software development …Profit

Questions?