Design and fabrication of a multipoint pH and temperature recording probe for real-time heart muscle monitoring

This paper demonstrates a silicon micromachined probe integrated with three Au/Cu-based resistance temperature detectors, three iridium oxide (IrOx)/AgCl pH meters and a PET flexible board as electric interconnect for heart muscle monitoring. The probe exhibits linearity of ≥98% and sensitivities of -52.75 mV/pH and 0.0259Ω/°C for the pH and temperature sensing, respectively, and has been successfully utilized for monitoring a frozen pig heart defrosted at room temperature in different depths. Measurement results show the pH-value and temperature difference between the outer and inner surface of the pig heart, which can be important factors to judge the occurrence of myocardial necrosis during the heart preservation.