Abstract
Hollow fiber membranes are found to allow the development of extremely small diameter (0.22 mm) probe and catheter-type pH and pCO2 sensors. These types of sensors can be comparable to the size of fiber optic sensors for these analytes. This work employs a concentric-flow geometry to direct a micro-flow of sweep solutions through hollow fiber membranes made of cuprammonium rayon and silicone. The sweep solutions establish a diffusive equilibrium with the external environment and then flow into optical absorbance cells. The optical system, which is remote from the sensor membranes, consists of two separate transparent capillaries, 555-nm surface-mount LEDs and photodetectors to monitor absorbance changes. In buffer, a ±0.01 pH unit resolution is achieved over the range of 7.02-7.87 with a 5-min 90% response time, and a 1.5-mm Hg pCO2 resolution is achieved from 0 to 80 mm Hg with a 15-min 90% response time.
Original language | English (US) |
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Pages (from-to) | 177-181 |
Number of pages | 5 |
Journal | Sensors and Actuators, B: Chemical |
Volume | 62 |
Issue number | 3 |
DOIs | |
State | Published - Mar 10 2000 |
Externally published | Yes |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Instrumentation
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry