Fiber-Optic Raman Probes for Biomedical and Pharmaceutical Applications - Emerging Raman Applications and Techniques in Biomedical and Pharmaceutical Fields - page 33

2.3 Miniaturized Raman Probes
Much effort has gone into determining ways to miniaturize fiber-optic Raman
probes for biomedical applications [14-33]. Most of the development has been
for probes designed for diagnosis of cancers and arteriosclerosis. Mahadevan-
Jansen et al. developed a fiber-optic probe equipped with band-pass and notch
filters and measured normal and pre-cancerous cervical tissues in vivo [21].
They reported that some silica signals obscure tissue Raman bands below
900 cm − 1 . Their probe was 12 mm in diameter. Motz et al. developed a Raman
probe with a 2 mm diameter equipped with filters and a ball lens following
their optical design strategy to optimize collection eciency and minimize
noise [26]. Figure 2.5 depicts the head design of their Raman probe. Their
probe's performance was tested through simulations and experiments with
tissue models and several in vitro tissue types. Buschman et al. reported
the potential of Raman spectroscopy in the determination of the molecular
composition of an artery wall in vivo using a Raman fiber probe [24]. They
demonstrated the use of forward-viewing and side-viewing Raman fiber probes
with diameters of about 2.5 mm on lamb and sheep in vivo. Our laboratory
has developed two kinds of fiber-optic Raman probes. One is made of bundled
Fig. 2.5. Head structures of the miniaturized fiber-optic Raman probes developed
by Motz et al. (modified from [29])