Biomedical Engineering Reference
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consisting of normal, basal cell carcinoma, squamous cell carcinoma, and
melanoma from 39 patients were investigated. Raman spectra were recorded
at the surface and at 20 um intervals below the surface for each sample, down
to a depth of at least 100 um. Data reduction algorithms based on the nonlin-
ear maximum representation and discrimination feature (MRDF) and dis-
criminant algorithms using sparse multinomial logistic regression (SMLR)
were developed for classification of the Raman spectra relative to histopa-
thology. The tissue Raman spectra were classified into pathological states
with a maximal overall sensitivity and specificity for disease of 100%.
Hammody et al. examined the differences in the IR spectra of melanoma
tissues and the surrounding epidermis in skin biopsies [98]. Biopsies of 55
patients were analysed and it was demonstrated that the technique could
differentiate melanoma from the epidermis using parameters derived from
absorbance bands. Additionally, the absorbances from tyrosine and phos-
phate that are abnormally elevated in malignant melanoma could be used
as markers.
Gastrointestinal Cancer
Spectroscopy has also been employed to study gastrointestinal tissues (apart
from the colon), the details of which are tabulated in (Table 4.7). For example,
N. Fujioka et al. reported on discrimination between normal and malignant
human gastric tissues by FTIR spectroscopy. Their aim was to determine
whether malignant and normal human gastric tissues can be distinguished
by the technique. As a result, 22 out of 23 gastric tissue samples and 9 out of
12 gastric normal samples were correctly segregated, yielding 88.6% accu-
racy. Subsequently, they concluded that FTIR spectroscopy can be a useful
tool for screening gastric cancer [99].
H. Barr et al. has published an excellent review paper about the role of
optical spectroscopy for an early diagnosis of gastrointestinal malignancy
and stated that fluorescence spectroscopy combined with vibrational spec-
troscopy offers the most realistic prospect of an early clinical condition and
is currently under evaluation. In addition, optical coherence tomography
can differentiate the layers of the oesophageal wall. Although complicated,
Raman spectroscopy offers the greatest information with possible develop-
ment of a molecular endoscope [42].
W. Petrich has published a review with the title of “Mid-Infrared and
Raman Spectroscopy for medical diagnostics.” The article gives examples of
the potential of the method in supporting medical diagnostics, most of which
have been performed in the field of internal medicine, namely, angiology,
haematology, rheumatology, endocrinology, gastroenterology, and nephrol-
ogy. Further potential applications in neurology, gynaecology, obstetrics
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