Header Format

The header struct variable includes the technical information that describes an ECG recording. The ECG recording is referred as the ECG_matrix in this document, and is a integer matrix with the raw ADC samples. This structure has a set of mandatory fields that must be included:

• freq, is the sampling frequency of ECG_matrix signal, or in other words, the reciprocal of the sampling interval or time (in seconds) elapsed between ADC samples.
• desc, description strings about each of the leads/signals. It is a char matrix of [nsig × description_length], where description_length is the length of the longer description string.
• nsamp is the number of samples of ECG_matrix, or the size of the first matrix dimension (rows).
• nsig is the amount of leads or signals of ECG_matrix, or the size of the second matrix dimension (columns).
• gain is a double precision vector of [nsig × 1] with the gain of each lead ( ADCsamples / μV ).
• adczero is a double precision vector of [nsig × 1] with the offset of each lead in ADC samples.

Also other fields described in the Physionet header are accepted by the kit, check the source code for more details.