Comprehensive Health Monitoring System

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?