IEEE Transactions on Biomedical Engineering · 1992 · 60 citations · 14 references
EngineeringBioengineeringBiomedical EngineeringBiosensorsPhotonicsSensorsAbsorption SpectroscopyFiber OpticsFiber-optic Medical DevicesOptical BiosensorsOptical SensorsPh AnalysisFiber-optic SensingFiber-optic SensorsOptical DetectionOptical Fiber SensorsPh Measurement In Body FluidsPh SensingResponse TimeSensor Technology
A new fiber-optic pH sensor system has been developed. The sensor uses an absorbtive indicator compound with a long wave-length absorption peak near 625 nm; change in absorption over the pH range 6.8 to 7.8 is reasonably linear. The sensor is interrogated by a pulsed, red LED. Return light signal is split into short and long wave-length components with a dichroic mirror; the respective signals are detected by photodiodes, and their photocurrents are used to form a ratiometric output signal. In laboratory tests, the sensor system provided resolution of 0.01 pH, accuracy of +/- 0.01 pH, and response time of 30-40 s. Following gamma sterilization, laboratory sensor testing with heparinized human blood yielded excellent agreement (e.g., r = 0.992 for n = 42) with a clinical blood gas analyzer. Excellent sensor performance and low cost, solid-state instrumentation are hallmarks of this sensor-system design.
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Fiber optic pH probe for physiological use
John I. Peterson, Seth R. Goldstein, Raphael V. Fitzgerald et al. · Analytical Chemistry · 1980 · 447 citations