1. User Needs
2. Design Components
2.1. Handle
2.2. Casing
2.3. Mouthpiece
2.4. Size
2.5. Shape
2.6. Materials
2.7. Weight
2.8. Data processing
3. Laws and Regulations
4. User experience
5. Function
5.1. Measure Tidal Volume
5.1.1. mechanical
5.1.1.1. Peak flow meter
5.1.1.2. Pressure laws
5.1.1.2.1. will this work as should not be forced breathing(increasing pressure of fixed container)
5.1.1.3. bellows (draw on drum)
5.1.1.4. Inflatable container
5.1.2. Electronic
5.1.2.1. Chest expansion
5.1.2.1.1. Measuring current
5.1.2.1.2. Xethru (uses radar)
5.1.2.1.3. Strain Gauge
5.1.2.2. Pressure difference pneumotacograph
5.1.2.2.1. prototype with straws and rising water due to change in pressure
5.1.2.3. Analyse audio
5.1.2.3.1. from phone
5.1.2.3.2. microphone
5.1.2.3.3. video
5.1.2.4. Vane meter
5.1.2.4.1. photosensitive sensor
5.1.2.4.2. mechanical measurer
5.1.2.4.3. method to stop vane spinning as soon as test is complete
5.2. Measure Reserve Volume
5.2.1. From Vital Capacity
5.2.1.1. Use equations in Simon Ward's lectures
5.2.2. Gas transfer
5.2.2.1. Nitrogen washout
5.2.2.1.1. Cheap ways of measuring nitrogen
5.2.2.2. Breath by Breath
5.2.2.2.1. measure nitrogen
5.2.2.2.2. Full breathing to find VC
6. Technology
6.1. Electronic
6.1.1. Battery
6.1.1.1. Long lasting
6.1.1.2. cheap
6.1.1.3. Type
6.1.1.3.1. Rechargeable
6.1.1.3.2. Disposable