High-resolution portable bluetooth module for ECG and EMG acquisition

Figures

• 

  Fig. 1. Hardware block structure.

• 

  Fig. 2. Track of the developed microcontroller firmware as a block diagram.

• 

  Fig. 3. Representation of correlation between analogue and digital values. (a) represents the original translation in the ADS129x's output. (b) represents the resulting translation after the distortion correction function is applied.

• 

  Fig. 4. GUI in acquisition tab with sample signal plotted. The controls are positioned on the left, with: Bluetooth® options to connect, disconnect, pause or resume acquisition; two selectors for the channel that will source the graphs; a sampling frequency slider for 1, 2 or 4 kHz; a graph sliding window size; and buttons to clear or download the acquired data. On the right, the two graphs show the acquired signal in real-time. Between the graphs, when the acquisition is paused, the user can scroll the window back to visualize the previous.

• 

  Fig. 5. The test functionalities window in connected state and acquisition paused.

• 

  Fig. 6. Assembled module with 10-electrode medical grade cable and 3-electrode to audio jack cable.

• 

  Fig. 7. Acquisition of the 8 simultaneous signals from the module. Channels 1 to 6 represent the ECG leads I, II, III, and V1, and sEMG from right and left flexor carpi radialis. Channels 7 and 8 are not accessible in the ADS1296 used, resulting in a constant 0 V. A factor of 1.5 mV shifts the signals to improve visibility.

• 

  Fig. 8. Visual Representation of the data reshaping performed by ‘algorithm 2’.

• 

  Fig. 9. Complexity from the three algorithms based on the big-o annotation. T represents the time consumed to iterate the input of size N.