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Measurements range and accuracy

Updated on 18 March, 2019

Aidlab’s sensors measure your heart’s ECG, respiration rate, attitude or skin temperature every time you use it. The sampling rate and resolution for some signals is presented as follows:

Accuracy of ECG and respiration rate monitor

Aidlab’s ECG and respiration monitor tracks the electric work of the heart and lungs. The respiratory rate is determined by Aidlab device by using the method of transthoracic impedance measurement. The chest has a basic electrical impedance (approximately 500 Ω) for a high frequency (64 kHz) test signal. When lung volume changes due to breathing, the impedance varies slightly from 0.2 to 5 Ω (peak-to-peak). By measuring and analyzing them we are able to determine the respiratory rate. Aidlab is able to detect impedance changes of ± 32 Ohms with a resolution of 16 bits.

These precise measurements can be influenced by several external conditions that you should consider when starting a measurement:

• Dry skin. Aidlab was made to fight this obstacle, but there can be some unreadable signals if your skin is too dry and will not conduct electricity. Air is not as good conductor as water.

• Other devices. Holding other electronic devices connected to electricity or being close to the source of a magnetic field will strongly influence Aidlab’s readings. Remember that your heart signal is weak compared to the signal collected from a hairdryer.

• No skin contact. To collect proper readings, electrodes should touch the chest. Aidlab will have problems measuring ECG or respiration rate if there is something - like hairs - between the sensor and the chest. Any dirt or mud will also influence the measurement.

The example output of Aidlab's signals can be reviewed here:

Accuracy of skin temperature sensor

You can review Aidlab's skin temperature sensor here.