A monitoring apparatus for non-invasively monitoring physiological parameters of an individual comprising: a monitoring garment (1, 30, 31) comprising a shirt for the torso of the individual to be monitored, one or more inductive plethysmographic, IP, sensors (4, 6, 20-25), each IP sensor comprising an inductance sensor including at least one conductive loop arranged to closely encircle the torso, such that the inductance of the conductive loop is responsive to the cross- sectional area of the torso enclosed by the loop, a cardiac cycle sensor (5, 7) for generating signals responsive to occurrence of cardiac ventricular contractions, a signal cable for carrying signals from said sensors, and a microprocessor unit comprising a microprocessor for receiving signals from said signal cable and for recording digital data derived from all received signals in a removable computer-readable memory media, wherein said monitoring apparatus further comprises circuitry for generating a variable-frequency signal from each IP sensor (4, 6, 20-25), the generated frequency being responsive to the inductance of the conductive loop of the IP sensor (4, 6, 20-25), and wherein the microprocessor unit further comprises circuitry for deriving digital data from the generated variable-frequency signals by sampling the variable-frequency signal and producing a digital data frequency output, the digital data comprising encoding of the variable frequency of the signals with errors of 100 ppm or less, the microprocessor being configured for subtracting a base carrier frequency from each frequency datum so that recorded frequency data are offset to have a substantially zero average frequency, and wherein the apparatus further comprises a memory accessible to the microprocessor, wherein the memory comprises encoded software instructions for causing the microprocessor to compress data before writing to the removable computer-readable memory media. a monitoring garment (1, 30, 31) comprising a shirt for the torso of the individual to be monitored, one or more inductive plethysmographic, IP, sensors (4, 6, 20-25), each IP sensor comprising an inductance sensor including at least one conductive loop arranged to closely encircle the torso, such that the inductance of the conductive loop is responsive to the cross- sectional area of the torso enclosed by the loop, a cardiac cycle sensor (5, 7) for generating signals responsive to occurrence of cardiac ventricular contractions, a signal cable for carrying signals from said sensors, and a microprocessor unit comprising a microprocessor for receiving signals from said signal cable and for recording digital data derived from all received signals in a removable computer-readable memory media, wherein said monitoring apparatus further comprises circuitry for generating a variable-frequency signal from each IP sensor (4, 6, 20-25), the generated frequency being responsive to the inductance of the conductive loop of the IP sensor (4, 6, 20-25), and wherein the microprocessor unit further comprises circuitry for deriving digital data from the generated variable-frequency signals by sampling the variable-frequency signal and producing a digital data frequency output, the digital data comprising encoding of the variable frequency of the signals with errors of 100 ppm or less, the microprocessor being configured for subtracting a base carrier frequency from each frequency datum so that recorded frequency data are offset to have a substantially zero average frequency, and wherein the apparatus further comprises a memory accessible to the microprocessor, wherein the memory comprises encoded software instructions for causing the microprocessor to compress data before writing to the removable computer-readable memory media.