Abstract: The invention relates to physiological sensor for measurement of carbon dioxide and a method of securing a carbon dioxide permeable membrane of the physiological sensor. The physiological sensor comprising a closed chamber containing a sensor liquid and being bounded, at least partially, by a carbon dioxide permeable membrane (12), at least two electrodes (10) provided within the chamber in contact with the sensor liquid, a support structure (23) for supporting the membrane (12); and at least one filament 28) wound around the support structure (23) and on top of the membrane (12) for securing the gas-permeable membrane (12) to the support structure (23).

Abstract: The invention provides a physiological sensing device for the measurement of pCO2, the device comprising: (i) a closed chamber bounded, at least partially, by a carbon dioxide permeable membrane; and (ii) at least two electrodes within said chamber, wherein said chamber contains a substantially electrolyte-free liquid in contact with the electrodes and the membrane and wherein the liquid comprises at least one metal or metalloid ion.