Table 3. A comparison of CW πNIRS to the state-of-the-art.

Approach	References	ACF resolution [ $\mathit{\mu }$ s]	Integration time [msec]	Source-collector separation [cm]
iDWS	[31,32]	3	100	1–5
SPAD array	[34,36]	3	30–100	1–1.5
Fiber bundle and APD array	[33]	0.2–3.2	6.5–29	1.4–2.9
CW $\pi$ NIRS	herein	0.9–1.6	2–10	1–3