traditional instrument, but “good
enough,” Wachsmann-Hogiu said. ;is
device could be used in the field to capture photos of blood samples and email
them to a pathologist.
;e spectroscopy attachment follows
the same principle of relative simplicity and low expense. ;e researchers
attached a small transmission grating to
the window of the cellphone, with two
additional apertures to collimate the
light. ;e results were not quite as sharp
as the spectra from a high-end spectrometer, but the cellphone attachment’s
components cost less than a dollar,
while the dedicated instrument would
(Left) The spectrum of a ;uorescent bulb taken by an iPhone spectrometer. (Right) A comparison of spectra from an iPhone and a commercial spectrometer manufactured by Ocean
Optics. While the iPhone is not as precise as the commercial unit, it accurately picks up the
peaks in color intensity.
350 400 450 500 550 600 650
350 400 450 500 550 600 650
Fluorescent bulb (iPhone)
Fluorescent bulb (oo)
;e group began its experiments
with an Apple iPhone 2, but the
attachments could be used on later
models of the iPhone and non-Apple
phones. ;e cellphone imagers could
find a home in the classroom as well as
the medical field.
Multi-Mode Imaging Probe
Could Detect Ovarian Cancer
University of Connecticut/Biomed. Opt. Exp.
Ovarian cancer is di;cult to diag- nose in its early stages because
symptoms often don’t manifest themselves until the disease has spread, and
also because there is no e;ective screening method. Researchers at the University of Connecticut and the University
of Southern California (U.S.A.) have
developed a multi-mode imaging probe
that could examine ovarian tissue via
minimally invasive surgery (Biomed.
Opt. Exp. 2, 2551; doi: 10.1364/
;e device built by Quing Zhu and
her colleagues integrates optical coherence tomography (OCT), photoacoustic
imaging and ultrasound into a single-probe device.
OCT is gaining ground in biomedical
imaging because it can reveal morpho-
logical changes and precancerous lesions
in the first few millimeters of tissue; how-
ever, ovarian tissue is so dense that OCT
cannot penetrate it beyond 1 to 2 mm.
Photoacoustic probes excel at revealing
angiogenesis, or the growth of excessive
blood vessels—which can be a sign that a
growth is turning malignant. Ultrasound
probes can detect deep morphological
changes in tissue. By combining these
three modes with their di;erent ranges
and functionality, scientists would get a
better view of the ovaries.
Co-registered images of malignant ovarian
tissue obtained with the hybrid imaging
device. (Top to bottom) OCT image, ultrasound image, superimposed photoacoustic
and ultrasound image and corresponding
histology. Yellow arrow: malignant tissue.
system. ;ey also want to make the
device less bulky and easier for physicians to use.