Hyperventilation or over-breathing  can have important consequences.  It paradoxically  starves the  brain of  oxygen and affects performance on different levels: 

physical - laboured breath, chest pains, fatigue, nausea, headaches

mental - poor concentration, fuzzy-headedness, impulsiveness

emotional - anxiety and panic, depression, emotional volatility.

It's a common, almost instinctive response to stress and anxiety. Under stress the breath tends to quicken and shift higher in the chest.

Carbon Dioxide & Why It Matters

The single most important factor in optimal breathing is carbon dioxide. Although it's a waste product, carbon dioxide serves vital functions in the body. Over-breathing  depletes carbon dioxide levels in the blood,  and  it's this that leads to the negative effects listed above.

Most breathing training focuses on the mechanics of breathing - how fast, how deep   without  necessarily  addressing  carbon dioxide levels.  You could learn very "proper" breathing mechanics - diaphragmatic breathing, etc. - and not affect your carbon dioxide levels - or even make them worse.

mircostream capnography,Handheld CO2 monitor,with cutting-edge NDIR(Non-dispersive Infrared) technology, solid craft design, provide reliable performance to users. measure Inspired CO2, End-Tidal CO2, Respiration rate, this device is only 0.5Kg, very best for ambulance, home care application.

Advanced features:

Cutting-edge NDIR technology, compatible Respironicx Loflo
Compensation gas includes O2, N2O, room air and anesthetic gas
Continue work more than 8-hours with rechargeable Li-battery
Compact design, only 0.5Kg

Specifications:

EtCO2
Method: Non-dispersive infared
Type: Sidestream or Mainstream
Measurement Range:  0 to 144mmHg, 0 to 15%
Accuracy: ±2mmHg
Resolution: 0.25mmHg
Sample Rate: 50mL/min(Sidestream/Ministream)
Compensation: Air, N20, O2

Respiration Rate
Rate: 2 to 120bpm
Resolution: 1 breath /min
Accuracy: ±2 breath /min

Trends
Memory: 96-hours data storage
Display: Real-time

Alarms
Indication: Visual & Audible
Mode: Mute,1 min/ 2mins/ Permanent

Interface
Screen Size: 2.8 inch Color LCD
Waveform: max 3 waveforms
Sweep Speed: 6.25, 12.5mm/sec

Power Requirements
Voltage: AC 100 to 240V,  50/60Hz
Power Consumption: 2W
Battery Type:  Rechargeable Lithium
Battery Life: Continuous 8 hours
Recharging Time: 4 hours

Environment Requirements
Operating Temperature: 15 to 35℃
Storage Temperature: -5 to 50℃
Humidity: 15%- 90%

Physical Property
Unit Dimension: 4 ×2 ×6cm
Unit net Weight: 0.5Kg
Packing Dimension:  20 11 15cm
Gross Weight: 1.5Kg

SpO2(Optional)
SpO2: 0-100%
Pulse Rate: based on SpO2

Accessories
Power adapter, Sample tube, Nasal tube, Water filter