Table 3.

Types of signals acquired by the prototypes presented in the included studies (N=50).

Signals acquired	Value, n (%)
Cardiac only [32,57,60,67-69,78,80,88,105,118]	13 (26)
Respiratory only [31,42,47,51,79,87,104]	8 (16)
Electromyography only [38,103]	2 (4)
Numerous signals [3,22,24-26,33,34,36,37,39,40,44,50,58,59,77,80,86,99,102,113,114,120]	27 (54)