Empatica E4 - Technical Specifications Overview

17
empaca
©
2015
2.1 TECHNICAL SPECIFICATIONS
The user should refer to the Technical Specicaon document to have a beer overview.
Below we will review only the main technical specicaons.
The expected life of the device depends mainly on the baery life which is 2 years.
PPG sensor
•
Sampling frequency 64 Hz (Non customizable).
• LEDs: Green (2 LEDs), Red (2 LEDs) Photodiodes: 2
units, total 15.5 mm
2
sensive area.
• Sensor output: Blood Volume Pulse (BVP) (variaon
of volume of arterial blood under the skin resulng
from the heart cycle).
• Sensor output resoluon 0.9 nW / Digit.
• Moon arfact removal algorithm:
• Combines dierent light wavelengths.
• Tolerates external lighng condions.
Infrared thermopile
•
Sampling frequency: 4 Hz (Non customizable).
• Range:
• -40...85°C for ambient temperature
(if available)*.
• -40...115°C for skin temperature.
• Resoluon: 0.02°C.
• Accuracy ±0.2°C within 36-39°C.
EDA sensor
•
Sampling frequency: 4 Hz (Non customizable).
• Resoluon: 1 digit ~900 pSiemens.
• Range: 0.01 µSiemens – 100 µSiemens.
• Alternang current (8Hz frequency) with a
max peak to peak value of 100 µAmps (at 100
µSiemens).
• Electrodes:
• Placement on the ventral (inner) wrist.
• Semi-permanent (screw in design).
• SUS03 stainless steel (standard) or Silver (Ag)
plated with metallic core.
• Electrode longevity:
• Lifeme (SUS03)
• 4–6 months (Ag)
3-Axis accelerometer
•
Sampling frequency: 32 Hz (Non customizable).
• High sensivity moon detecon across 3 axes:
X,Y, and Z.
• Default range ±2g.
• Ranges of ±4g or ±8g are selectable with custom
rmware.
• Resoluon: 8 bits of the selected range.
E4 operang range:
•
Relave Humidity 60 ±25% H.R.
Water resistance:
•
IP 22 - E4 is protected against inseron of ngers
and will not be damaged or become unsafe if
exposed to vercally or nearly vercally dripping
water.
* This is not generally available but can be turned on with custom engineering work.