Technology Transfer Office
of the Institute for Physical Research, NAS of
Armenia
Registration Number: ___________
Date: “___“ ______________ 20___
“Optical screening device for medical diagnostics”
Technology ID
Basic data
1. Technology background
 Market need for the technology developed by the inventor
Medical imaging, screening and tomography are indispensable tools for diagnostics and treatment of
large variety of illnesses. Existing technlolgies and devices are based on ultrasonic acoustic waves, X- and
γ- rays, nuclear magnetic resonance, terahertz radiation, which are either expensive (γ- rays, nuclear
magnetic resonance, terahertz radiation) or harmful because of exposure of ionizing radiation (notably, Xand γ- rays).
We have developed a new technique for optical screening and imaging of up to 5 cm-thick biological
objects (e.g., human palm and wrist). It can be used for graphical (grayscale or 3D) visualization of bone
tendon and vascular structure of the hand, which will be helpful for revealing fractures, tumors and
anomalies. The developed device is cost-effective as compared with the above mentioned ones, entirely
harmless, and can be used as an alternative to known devices for specific applications where safety,
portability, continuous operation and low cost are of primary importance.
 Conceptual working methodology for the technology
The technique is based on straightforward optical transmission of single modulated several-mW cw nearinfrared laser diode beam by means of its synchronous spatial scanning together with photo-detector
across the unmovable tested object placed in-between. This approach is advantageous because of higher
attainable sensitivity. The method relies on highly-sensitive lock-in detection, acquisition and data
processing techniques, which allows overcoming problems imposed by large absorption and, especially,
scattering.
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The studied object is placed on a flat unmovable object table located between the laser diode (λ = 780 or
850 nm, P ~ 5 mW, Ø 1 mm) and solitary photodiode followed by operational amplifier. The laser diode
and photodiode are connected rigidly on a movable 2D X-Y scanning holder which is driven pixel-by-pixel
by computer DAQ card-controlled stepper motors. Recording and processing of acquired transmission
signal are also realized through the same DAQ card. The software code written in LabVIEW language
allows to easily adjust the number of X and Y pixels, scanning step for the chosen mapping area, and the
scanning rate (linked to sensitivity) depending on particular task.
Implementation of modulation of laser diode amplitude synchronized with measurement step and
synchronous detection of the photodiode signal using lock-in amplifier followed by real-time data
processing allowed us to attain the maximum sensitivity determined by noise equivalent power (NEP) of
the photodiode, as well as to reduce the hindering contribution from the background illumination and
gradual overall transmission changes across the object. Phase-sensitive lock-in detection also helps to
diminish multiply scattered (diffused) light component and enhancing the contribution of the signal
originated by ballistic and least-deflected photons.
At each step, the DAQ card averages specified number of measurements of lock-in amplifier voltage,
storing this value in a resulting data file. The latter is then presented graphically as a grayscale graph or 3D
image with Z axis showing the intensity of the transmitted radiation.
 Benefits of the technology
Since to our knowledge there are no commercial optical medical imaging devices, direct comparison can
be done with compact X-ray devices (unit price about 10000 USD). The advantages are: 1) safety (no
ionizing radiation), hence the screening can be performed continuously as required in the course of
diagnostics and treatment- no accumulative exposure problems; 2) easier digitalization and computer
processing of the output image: in our case it is intrinsic, while for X-rays the digital recording unit costs
about 3-fold more expensive as the film-based device itself; 3) in the case of proper optimization of
regimes, one can reach the same operation performance at a lower price.
 Application area to be focused upon
The main addressed application is medical diagnostics, namely optical screening and imaging of up to 5
cm-thick biological objects (e.g., human palm and wrist) to reveal fractures, tumors and anomalies of
bones, soft tissues, and vascular system.
Possible applications may also include other areas where screening and imaging of highly scattering and
absorbing objects is important, namely: security systems; quality testing and control in the industry
(detection of homogeneity and thickness imperfections in non-metallic material sheets and slabs);
readout of hidden information (EAN code- type marking), etc.
2. List of patents/ applications filed by the inventor for the particular technology (if
applicable).
There are none.
3. Present state of the technology
Laboratory prototype device is developed (both hardware and software); the operation is not yet
optimized for optimal performance.
 Lab test
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Since the optimum transmission for biological tissues occurs in the near infrared wavelength region (650–
1300 nm), all the tests were done with 780 or 850 nm wavelength laser radiations. The first tests were
done with flat model objects that combine absorption and scattering, namely, different absorbing objects
sandwiched in sheets of printer paper bearing scattering (see Fig.1). These tests were aimed at revealing
and optimization of spatial resolution and detection sensitivity. Similar results have been obtained for the
case of several cm-thick uniform macro-homogeneous scattering layers, e.g. foam rubber.
a)
b)
c)
d)
Figure 1. Examples of transmission images of objects enclosed between 20 sheets of similar paper (by 10 from each side): a)
steel razor; b) leaf; c) letters printed in black; g) paper clip.
Second set of tests has been performed to implement and optimize the radiation modulation and lock-in
(synchronous) detection technique (see above). This step is important to attain the maximum sensitivity,
as well as to overcome the problems of hindering contribution from the background illumination and
gradual overall transmission changes across the object arising when we switch to real biological
structures. Phase-sensitive lock-in detection also helps to diminish multiply scattered (diffused) light
component and enhancing the contribution of the signal originated by ballistic and least-deflected
photons.
a
b
c
d
Figure 2. The transmission images of ruler (a,b) and coin (c,d) sandwiched between the printer paper sheets: Pictures a),c):
direct transmission signal (no lock-in detection); pictures c),d): with lock-in detection.
As one can see from Fig.2, this measure indeed helps to visualize merely abrupt spatial changes, which in
real medical options can be e.g. bone fractures or cracks.
The last set of tests was done with human hands (palm area excluding fingers). Note that according to
literature, direct optical transmission screening becomes inefficient already at millimeter thickness
because of big scattering. Thanks to key features of our technique, we were able to visualize without
strong reduction of spatial resolution.
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Fig.3 shows the results of these tests. The top picture (a) presents the hand image taken by
straightforward transmission method (no lock-in detection). The drawbacks are poor spatial resolution
and ~ 100-fold change of overall transmission signal measured across the object (from 4 cm-thickness
towards the wrist to 2.5 cm-thickness towards the fingers). Implementation of lock-in signal detection
(bottom-right picture, c) helps indeed to overcome these problems, allowing to clearly see the outlines of
bones and vascular structure.
Figure 3. Transmission grayscale images of
human hand (fragments of palm area
excluded fingers). a) no lock-in detection; c)
with lock-in detection for the screening area
marked by a red square in b).
a)
b)
c)
X-ray image of
palm
f
palm
Optical differential-mode image of palm (fragment)
Further optimization requires substantial improvement of hardware solutions (2D scanning system,
photodetecting unit, etc.), and is not yet done because of lack of funding.
 Comparative test results with competitor technologies (if applicable)
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To our knowledge there are no commercial optical medical imaging devices in the market. R&D studies
are under way in several scientific labs, mainly focused at
4. Details about previous collaborations
 Any existing partnerships with any institutes/ companies for developing the technology
There are none.

Collaboration with other researchers
No working projects. Collaboration intention statement with Saratov State University, Russia (group of
Prof. V. Tuchin- worldwide-known expert in optical medical diagnostics and treatment), as well as with
National Institute of Health (USA).
 Details about any previous attempts to commercialize the technology
Application was presented to CRDF Technology Entrepreneurship Workshop, Yerevan, 2011.
Additional data
5. Estimated funding (maturation proposal) for developing the technology
 Approximate amount of capital required to develop the technology completely
According to our estimates, optimization of technology to meet the market demands, notably on spatial resolution
of ~ 0.5 mm and duration of scanning set (~ 10-30 s max.) will require extra funding of about 2000 USD.
The amount of further expenses to develop the technology completely (fabrication of prototype device sample,
testing facilities and procedure, market analysis, patenting [if needed], etc.) is difficult to estimate.
6. Any other information regarding possible competitors
No information.
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