1. Measure heart rate
1.1. funtion requirements
1.1.1. precise heart rate
1.2. design
1.2.1. MAX 36100/30102 sensor
1.2.2. micro controller ESP 8266
1.2.3. 2,5 - 5,5 VDC
1.2.4. Efficient
1.2.5. I2C, TTL signal level
1.2.6. +- 3 bpm
1.2.7. 1,9*1,4*0,3(cm)
1.3. Analysis
1.3.1. contract with heartbeat
1.3.2. measuring the periodic changes
1.4. risk
1.4.1. motionartifacts
1.4.2. sensitivity to light
1.5. countermeasure
1.5.1. filter noise
1.5.2. improve signal stability
2. Non-contact body temperature mesurement
2.1. funtion requirement
2.1.1. Quickly
2.1.2. Non-control
2.1.3. Mitigation the rate of cross-infection
2.2. Design
2.2.1. MLX90614 sensor
2.2.2. Micro controller
2.2.3. 3,3 to 5V
2.2.4. 1,5 mA
2.2.5. Temperature range: 70 to 380 celcius degree
2.2.6. Measuring range: 2 to 10 cm
2.2.7. Sweep angle: 80 degree
2.2.8. Small, low cost
2.3. Analysis
2.3.1. The priciple of thermal emission of objects
2.3.2. Lens
2.3.2.1. Focus the light from the objects
2.3.3. Receive input
2.3.3.1. converts into heat
2.3.3.1.1. Tranformed into electrical signal
2.4. Risk
2.4.1. Confuse
2.4.2. Narrow scanning angle
2.4.3. deadzone
2.4.4. not detect through obstacles
2.4.5. short sensor range
2.4.6. high temperature, dust, humidity
2.5. Contermeasure:
2.5.1. Stable measurement distance
3. Data transmission
3.1. Function requirements:
3.1.1. Wireless
3.1.2. stable
3.1.3. low-power
3.2. Design:
3.2.1. chip
3.3. Analysis:
3.3.1. Wireless communication
3.3.2. bluetooth low energy
3.4. Risk:
3.4.1. High energy consumtion
3.5. Countermeasure:
3.5.1. Auto reconnect
3.5.2. Optize wireless power usage
4. Mearsure SpO2
4.1. Function requirements
4.1.1. estimate the oxygen saturation
4.1.2. different light and skincare
4.2. Design
4.2.1. MAX 36100/30102 sensor
4.2.2. PPG sensor
4.2.3. wave lenghts
4.2.4. micro controller ESP 8266
4.2.5. sperationg voltage
4.2.6. efficient
4.2.7. I2C, TTL signal level
4.2.8. +- 2% bpm
4.2.9. 1,9*1,4*0,3(cm)
4.3. Analysis
4.3.1. Intergrated
4.3.2. Receive from Esp 8266
4.3.3. Component
4.3.3.1. 2 LEDS
4.3.3.2. Photodetector
4.3.3.3. Improved optics
4.3.3.4. Low noise analog signal processing
4.3.3.5. 1,8V and 3,3 V power sources
4.3.3.6. Affordable
4.4. Risk
4.4.1. Ambient light onterference
4.4.2. Poor sensor placement
4.5. countermeasure
4.5.1. use instruction
4.5.2. warm and rub the skin
4.5.3. topical vasodilator
5. Power supply and energy consumption
5.1. function requirement:
5.1.1. Stable
5.1.2. Low power consumption
5.2. design
5.2.1. power-saving mode
5.2.2. Rechargeable battery
5.3. Analysis:
5.3.1. Manage power consumption
5.4. Risk:
5.4.1. Waste energy
5.4.2. Battery drain quickly
5.5. Countermeasure:
5.5.1. Use PMIC
5.5.2. Auto-sleep mode
6. Display result
6.1. Function requirements:
6.1.1. Clear
6.1.2. Readable
6.2. Design
6.2.1. LCD OLED 0,96 inch display
6.3. Analysis:
6.3.1. Realtime display
6.4. Risk:
6.4.1. Delay
6.4.2. Hard to read in bright light
6.5. Countermeasure:
6.5.1. Auto-adjust brightness
6.5.2. Increase display refesh rate