Abstract: A cerebrospinal fluid (CSF) detection device includes a headband including at least four electrodes integrated into the headband. The electrodes are configured to make electrical contact with a person's head when the headband is placed on the person's head. The CSF detection device also includes an impedance circuit integrated into the headband and coupled to the at least four electrodes. The impedance circuit includes memory and an impedance analyzer coupled to the at least four electrodes and is configured to measure an impedance of the person's head. A first pair of the at least four electrodes is used by the impedance circuit to inject an electrical signal into the person's head and a second pair of the electrodes are used by the impedance analyzer to sense a signal. The first pair of electrodes is interleaved within the headband with respect to the second pair of electrodes.