An impedance measurement apparatus, for performing impedance measurements on a subject, the apparatus including: a) an input device, to receive input commands from an operator, b) a first processing system, coupled to the input device, and c) a second processing system coupled to the first processing system, wherein the second processing system: (i) applies one or more signals to the subject via electrodes (13, 14); (ii) receives an indication of the one or more signals applied to the subject via electrodes (15, 16); (iii) receives an indication of one or more signals measured across the subject; (iv) performs at least preliminary processing of the indications to thereby allow impedance values to be determined, characterised in that d) the first processing system includes a memory storing profiles representing predetermined impedance measurement procedures, wherein the first processing system: i) determines one of the impedance measurement procedures in accordance with input commands received by the input device from an operator; and, ii) selects instructions corresponding to the determined impedance measurement procedure; and e) the second processing system includes a programmable module controlled using the selected instructions, wherein the second processing system: (v) generates, using the instructions, the control signals being used to apply one or more signals implementing the determined impedance measurement procedure to the subject; and (iv) performs, using the instructions, at least preliminary processing of the indications to thereby allow impedance values to be determined. a) an input device, to receive input commands from an operator, b) a first processing system, coupled to the input device, and c) a second processing system coupled to the first processing system, wherein the second processing system: (i) applies one or more signals to the subject via electrodes (13, 14); (ii) receives an indication of the one or more signals applied to the subject via electrodes (15, 16); (iii) receives an indication of one or more signals measured across the subject; (iv) performs at least preliminary processing of the indications to thereby allow impedance values to be determined, (i) applies one or more signals to the subject via electrodes (13, 14); (ii) receives an indication of the one or more signals applied to the subject via electrodes (15, 16); (iii) receives an indication of one or more signals measured across the subject; (iv) performs at least preliminary processing of the indications to thereby allow impedance values to be determined, d) the first processing system includes a memory storing profiles representing predetermined impedance measurement procedures, wherein the first processing system: i) determines one of the impedance measurement procedures in accordance with input commands received by the input device from an operator; and, ii) selects instructions corresponding to the determined impedance measurement procedure; and i) determines one of the impedance measurement procedures in accordance with input commands received by the input device from an operator; and, ii) selects instructions corresponding to the determined impedance measurement procedure; and e) the second processing system includes a programmable module controlled using the selected instructions, wherein the second processing system: (v) generates, using the instructions, the control signals being used to apply one or more signals implementing the determined impedance measurement procedure to the subject; and (iv) performs, using the instructions, at least preliminary processing of the indications to thereby allow impedance values to be determined. (v) generates, using the instructions, the control signals being used to apply one or more signals implementing the determined impedance measurement procedure to the subject; and (iv) performs, using the instructions, at least preliminary processing of the indications to thereby allow impedance values to be determined.