Post on 19-Feb-2016
description
transcript
Comprehensive Health Monitoring System
Sponsored by:
Dept. of Veterans Affairs
Group #5
Samuel RodriguezDaniel ThompsonChadrick WilliamsGiselle Borrero
Physical Layout
Hand UnitChest UnitWaist Unit
Thigh Unit
Project Description Wireless monitoring pulse oximeter, blood oxygen
concentration (SpO2) and fall detection Consists of four units
◦ Receiving Display unit (RDU)◦ 3 Transmitting Sensor Units (TSU)
All units will be worn by the patient Finger sensor will obtain pulse and SpO2 and
transmit Chest and thigh sensor will determine patients
posture information Waist display will receive data, display data, and
transmit emergency signals
Goals Ultimately to monitor patients for chronic
heart and related health conditions Remotely contact emergency services Provide location to emergency services of
patient More affordable than existing wireless units Ideal for a variety of users Maximum protection at minimal to no cost
ObjectivesTransmitting Sensor Units (TSU) To be worn on the finger, wrist, chest and right thigh Battery powered Control the pulse oximeter sensor Make calculations to achieve pulse and oxygen concentration data Determine the posture of the patient Measure patient’s angular velocity and acceleration Monitor unit’s battery life Transmit data wirelessly to the waist unit (RDU)
Receiving Display Unit (RDU) Receive data wirelessly from TSUs Display patient’s pulse and oxygen concentration Contact emergency services Monitor unit’s battery life Audible and visual alerts for critical conditions, loss of signal and
battery life, and display personal information
Pulse Oximeter• Non-invasive optical measurement of heart
rate and blood oxygen saturation • Hemoglobin is the red colored substance in
blood and is the carrier of oxygen• Red and infrared light are attenuated less by
the body tissues and more by blood (600nm, 940nm)
• Light shines through finger and strikes a photodiode, which creates a very small current based on the amount of light incident on the photodiode
• This determine attenuation of light based on the output of the photodiode
Sensor◦ Generate alternating pulses of light at 600nm (red) and
940nm (infrared)◦ Photodiode must detect light in the range of 600nm to
940nm◦ Convert photodiode current to voltages values between
0V to 2.3V◦ Accuracy of ±2% (70% - 100%)◦ ±2 BPM for pulse
Transmit a maximum of 10 ft MCU
◦ Two DACs 12-bits◦ Three ADCs 12-bits◦ 12 GPIOs
Pulse Oximeter Design
Pulse Oximeter Subsystem
To calculate pulse oximetry the photodiode current must be converted to a voltage
This voltage has both a DC and AC component that represents attenuation of light
DC-constant volume of blood used for auto gain control AC – ebbing and flowing of blood used for measurements
Pulse-Ox Sensor
Control alternating pulses by pair of LED select lines (STG3155)
Common power lines DAC controls current
through system to avoid damage to LEDs
Sensor Control
MCU determines DAC output based on DC component input Utilizes constant DC equation because the DC component from the red
and infrared LEDs must be the same AGC constantly monitors output from diode and adjusts to maintain
the same voltage Co is the concentration of oxyhemoglobin (Hb02) Cr is the concentration of reduced hemoglobin (Hb) is the absorption coefficient of Hb02 at wavelength is the absorption coefficient of Hb at wavelength
Automatic Gain Control
𝑆𝑝𝑂2=𝐶𝑜
𝐶𝑜+𝐶𝑟=
∝𝑟 2𝑅−∝𝑟 1
(∝𝑟 2−∝𝑜2 )𝑅− (∝𝑟1−∝𝑜1 )
TSU – Pulse Oximeter
Pulse Oximeter
Chest and Thigh Fall Detection Design Determine the patient’s position (sitting,
standing or laying down) Measure angular velocity and acceleration
of patient Have a range of ±6g acceleration. Have an accuracy of angular velocity
between ±300˚/s to ±500˚/s Have a sampling rate of at least 120Hz
Consist of:◦ Two 3-axis gyroscopes (ITG-3200)◦ Two 3-axis accelerometers
(MMA7631L)◦ One of each in the center of the
chest and right thigh MCU MSP430FG438
◦ Three 12-bit ADCs◦ 34 GPIOs
RF Transceiver CC1101
Fall Detection Design
Fall Detection Block Diagram
TSU – Fall Detection
TSU – Fall Detection
RF transponder receives information from peripheral units
Multicontroller stores past data and makes decisions about patient status
16x2 LCD displays patient information, alerts, emergencies, or system status
Buzzer and LEDs provide visual and auditory stimulus for alerts
RDU Design
Waist Block Diagram(Receiving Display Unit)
Waist Schematic
Waist Schematic
Part number Component size (mm2)
Number of I/O pins Extra built-in features
Cost($)
JN5148 8 x 8 21 2.4GHz transceiver, 12-bit ADC, 12-
bitDAC, 4 wire audio interface
20
CC430 9 x 9 32 - 64 Sub 1GHz transceiver, 12-bit
ADC, CC1101
5.00*
MSP430F233 12 X12 48 12-bit ADC 2.50*
MSP430F2616 12 x 12 or 14 x14
48 or 64 12-bit ADC, 12-bit DAC, DMA controller
5.85*
MSP430FG437 14 x 14 48 12-bit ADC, 2x 12-bit DAC,3x Op Amps,
Analog comparator, DMA, SVS, LCD
driver
5.15*
Multicontroller
Separate unit from the MCU Built-in display controller May display pulse, blood oxygen content,
patient’s name, or alarm information
Liquid Crystal Display
Green LED- Blinks if a fall is detected Blue LED- Blinks if RDU loses signal from
peripherals Red LED- Blinks if emergency is active or
user has indicated panic Piezoelectric Buzzer- Pulses if emergency is
active
Alert Protocol
All units powered by a battery, through a DC/DC buck converter
2.5V supply to Gyroscope logic 3.3V supply to MCU, RF transceiver, and all
sensor units 5V supply to LCD Battery voltage monitored by built-in
comparator in the MSP430FG43x
Power Management
3.3V output supplies MCU and sensors, and another buck converter supplies 5V for the LCD anode
Buck DC/DC converter
Analog to digital converter internal to MCU
Output to Red-Yellow-Green LED
Voltage divider from battery, scaled with the MCU’s maximum input voltage
Battery Life Monitoring
Development Environments Language: C, JAVA
Testing: DevC++ V 4.9.9.2
Implementation: Code Composer Studio V4.2.1.00004, eclipse
Schematics: Cadsoft EAGLE V 5.11.0
Development Kit
MSP-FET430UIF EM430F6137RF900
Class Diagram
Class Diagram
Class Diagram
Class Diagram
Sequence Diagram
Activity Diagram
Fall Detection AlgorithmAccurate, Fast Fall Detection Using Gyroscopes and Accelerometer-Derived Posture Information
Fall Detection - Acceleration Sample Output
The linear acceleration and rotational rate of the chest and thigh for:◦ Standing◦ Walking◦ Sitting◦ Running
Functions
The uses-permission function is needed in order to use Bluetooth features in any application. This is required to perform different types of communication such as requesting and accepting connections, and transferring data.
The mBluetoothAdapter function is needed for any and all Bluetooth activity. It represents the Bluetooth adapter, or Bluetooth radio, and is used for the entire system.
The REQUEST_ENABLE_BT function is to ensure that the Bluetooth is enabled. If the Bluetooth on the device is set off, this function prompts the user to enable Bluetooth through the system settings without stopping the application.
Bluetooth
<uses-permissionandroid:name=“android.permission.BLUETOOTH”/>;mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
Functions
The startDiscovery() function searches and scans for other dvices. The scanning of devices takes about 12 seconds to complete and scans constantly.
The REQEST_CONNECT_DEVICE function is needed to actually connect to two devices. This is enabled by using the Bluettoth service socket which accepts a connection request and performs the connection.
The callIntent function allows the android application to make a phone call. The number is preset is this function.
Bluetooth
mBtAdapter.startDiscovery();startActivityForResult(serverIntent, REQUEST_CONNECT_DEVICE);startActivity(callIntent);
Bluetooth
BudgetSubsystemWaist $77.20Chest $75.98Hand $36.50Thigh $75.98Design $438.24Total $703.89
SubsystemWaist $90.72Chest $70.98Hand $54.39Thigh $70.98Design $199.00Total $486.07
Original budget Final Budget
Questions?