Optical system to characterize the gross contractile response of a tissue-equivalent collagen matrix

Abstract

We present the theoretical operation and experimental results of a fiber optic interferometer, which we have used to measure the surface displacement of a collagen gel. Dispersed within the collagen gel are fibroblast cells. We describe a measurement system to assist in the detailed study of the biochemical and mechanical processes involved in fibroblast cell contraction. The interferometric system is non-contacting and offers a large dynamic range of measurement. Digital demodulation of a phase generated carrier results in an experimental sensitivity limit on the order of tens of nanometers with a measurement range of up to 2 mm. Computer-controlled data acquisition allows measurement of the contracting gel host over a period of several hours. We describe the optical interferometric system and present experimental results on a contracting collagen gel.

Modern Metrology Concerns

“…Specific examples will be cited throughout the literature as well as from our own research. Our research in digital demodulation techniques include applications in myofibroblast cell contraction (Kern et al, 2003), ballistic shock characterization (Kumar et al, 2009), and down-hole oil well drilling. In addition, we present a new (unpublished) digital demodulation algorithm.…”

Digital Demodulation of Interferometric Signals

“…This system is based on real-time digital processing of the interferometer's signal in the time domain. We have used this demodulation system to characterize the contraction of myofibroblast cells within a collagen matrix (Kern et al, 2003). In Section 3 of this chapter, we present a new demodulation algorithm whose kernel is based on a frequency domain analysis of the interferometer's phase-generated carrier signal.…”

“…Specific examples will be cited throughout the literature as well as from our own research. Our research in digital demodulation techniques include applications in myofibroblast cell contraction (Kern et al, 2003), ballistic shock characterization (Kumar et al, 2009), and down-hole oil well drilling. In addition, we present a new (unpublished) digital demodulation algorithm.…”