Blood pH optrode based on evanescent waves and refractive index change

• Sensing pH in blood with an silica multimode optical fiber. This sensor is based on evanescent wave absorption and measures the change of the refractive index and absorption in a cladding made of a biocompatible Polymer. In contrast to many existing fiber optical sensors which are based upon different dyes or florescent material to sense the pH, here presents a solution where a part of the cladding is replaced with a Poly (β-amino ester) made of 1.4-Butanediol diacrylate, Piperazine, and Trimethylolpropane Triacrylate. Piperazine has the feature of changing its volume by swelling or shrinking in response to the pH level. This paper utilizes this dimension effect and measure the refractive index and the absorption of the cladding in respect to different pH-levels. The alteration of refractive index also causes a change in the absorption and therefore the output power changes as a function of the pH level. The sensor is sensitive to pH in a wide spectral range and light absorbency can be observed for wavelengths ranging from UV to far IR. © 2014 SPIE.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Medicinteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Medical Engineering (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Keyword

Absorption

Blood

Evanescent wave

Hydrogel

Optical fiber

PH

Sensor

Publication and Content Type

ref (subject category)

kon (subject category)