Eric Murray
Tim Ficarra
Barbara Deschamp
 Eric
• Spectroscopy
 Tim
• Reverse Iontophoresis
 Barbara
• Fluorescence
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Study of the interaction of matter and light
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Light is focused on some area of the body
Light is absorbed and reflected in different ways by
different substances.
Subcategories include near-infrared, mid-infrared,
and photoacoustic spectroscopy.
Goal is to understand glucose's
spectroscopic properties, in order to
identify its presence in a sample
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Functions in .7 – 2.5 micrometer range
Explores tissue depths of 1 to 100
millimeters
Diffuse Reflection:
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Using NIR light to illuminate a spot on the body
Light is partially absorbed, scattered, and
reflected back to a detector
Reflectance spectrum of skin is compared to
reflectance spectrum of the glucose.
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A graph of the absorbance spectrum of
skin contains different spectral
signatures for different components that
are present.
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Glucose bands located at 1613, 1689, 1732,
2105, 2273, and 2326 nm.
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Work by Malin et al. Used custom-built
scanning near-infrared spectrometers.
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Detectors were composed of indium-galliumarsenide
Human forearm was the target
Instrument observed the intensity spectra for
diffuse reflectance for the wavelength range
1050-2450 nm
Sampling interval was 1 ns.
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Data from Malin's experiments
Prediction error of 9.1%
Prediction error of 3.6%
Image Source: Malin, Stephen F, et al. “Noninvasive Prediction of Glucose by Near Infrared Diffuse Reflectance
Spectroscopy.” Clinical Chemistry, Vol. 45, No. 9. 1999
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Sensys GTS by Sensys Medical, Inc.
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Been in development for 16 years
Design changes have been a result of the
dynamic nature of skin
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Texture
Color
Temperature
Further design changes to address positioning
of the skin.
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Glucose is very effective at absorbing
mid-infrared light
Unfortunately, so is water
The body's emission spectrum can be
used to measure glucose.
If the glucose to be measured is at the same
temperature as the tissue it's present in, no
glucose spectrum will be observed in the
emission spectrum.
Mid-Infrared
Spectroscopy
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Developed by OptiScan
Biomedical Corporation.
Uses mid-infrared
spectroscopy
Unfortunately, their
current implementation is
invasive, drawing blood
every 15 minutes.
Used for patients in
critical condition.
Image source: http://optiscancorp.com/optiscanner.html
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A beam of light is used to heat a target.
Optical energy from the light is
converted into acoustic energy.
This acoustic wave can be measured with
a microphone.
The optimum wavelength for glucose
detection is 9.676 micrometers.
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One study (MacKenzie et al.) used nearinfrared pulse laser sources, and
piezoelectric transducers.
The following relationship was found:
y = 0.21x – 0.02
where y is the change in the photoacoustic
response and x is the glucose concentration
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Correlation coefficient was 0.99
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Very accurate and promising
Equipment is expensive
Testing equipment is extremely sensitive
and requires a controlled environment.
 Technique
for extracting subdermal
molecules
• Apply DC current to the skin
• Current attracts charged molecules
• Force of the flow also draws neutral molecules
 Glucose
and lactate are among the
molecules which can be extracted
 First
commercially available non-invasive
glucose measurement technique
• Continuous monitoring
• Requires blood test for calibration
• Suffers inaccuracy in detecting hypoglycemia
 Discontinued
2007
by Animas Corporation in
 There
is a metabolic relationship
between lactate and glucose levels
• Lactate can be extracted using reverse
iontophoresis
• Lactate measurement could be used to improve
accuracy of GlucoWatch or similar technologies
 Lactate
measurement is still being
investigated
 Tool
for blood sugar testing
• Two minute test
• Utilizes five sensors
 In regions rich with sweat glands
 2 hands, 2 feet, 1 forehead
 Requires
no calibration
 Still in developmental stages
 Metabolic
heat conformation
 Carbon nantoubes (reverse iontophoreris)
 Fluorescence
Focus is on Fluorescence by means of a
contact lens, most diabetics need corrective
lenses due to vision problems caused by the
disease
 Ultimately it was most continuous and non
invasive form
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 Emission
of light by a substance that has
absorbed light of a different wavelength
• Wavelength A is absorbed
• Wavelength B is then emitted
 Using
a boronic acid doped contact lens,
glucose levels are monitored through
tears binding with the boronic acid
 The sensor responds to the different
concentrations through the diffraction of
light7 therefore changing fluorescence
and wavelength
 Measurements are taken by a handheld
device that correspond to blood glucose
levels
 It
is a electron deficient acid
 With the presence of glucose becomes
electron rich
 The changes of the boron atom can be
noticed by fluorescence spectral changes in
the probe
 Doped
lenses which react to tear glucose
level and measured by handheld device
 Sensors on the lens that change color
according to the glucose concentration in
tears
 Elevated
tear glucose levels were first
demonstrated by Michail, as early as 1937 7
 Does
not suffer from fluctuations of ambient
light
 Has a 30 min lag time with blood glucose levels
 Correlation coefficient of 0.998 9
• Response to various pH (in the range of
6.5-8.5)
• Polarity response
• Sensitivity enough to detect low
concentrations of healthy person the high
levels of a diabetic
• Comfort (daily disposable contact lens)6
 Biocompatibility
 Sensitivity
 Low
pH and polarity
 Toxicity (one study uses off the shelf
lenses)7
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1. Current development in non-invasive glucose monitoring, Amaral et al.,
Science Direct, Medical Engineering & Physics 30(2008)541-549
2. A glucose-sensing contact lens: from bench top to patient, Lakowics,
Current Opinion Biotechnology 2005;16,100-107
3. Fluorescent measurement in the non-invasive contact lens glucose sensor.
Diabetes Technology Therapeutics 2006;8, 312-317
4. Fluorescence glucose detection: advances toward the ideal in vivo
biosensor, Moschou et al Journal of Fluorescence, 14,5: September 2004
5. Current Problems and Potential Techniques in In Vivo Glucose Monitoring,
Wickramasinghe et al, Journal of Fluorescence, Vol 14, : September 2004
6. Clinical trial of noninvasive contact lens glucose sensor, March et al
Diabetes Technology Therapeutics. Volume 6; 782-789Dec 2004
7. A Glucose sensing contact lens: A new approach to non-invasive
continuous physiological glucose monitoring, Badugu et al, Journal of
Fluorescence vol. 13, No.5 September 2003
8. The Pursuit of Noninvasive Glucose: “Hunting the deceitful Turkey”, John L.
Smith
9. Contact-lens Type Glucose Sensor Fabricated using Bionic-Mems
Techniques for monitoring of Tear Sugar, Chu, Tokyo
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10.. "Diabetes Statistics - American Diabetes Association." 26 Jan. 2011. Web. 28 Feb. 2011.
<http://www.diabetes.org/diabetes-basics/diabetes-statistics/>.
9. Mathur, Ruchi. "Hemoglobin A1c Test Information on MedicineNet.com." MedicineNet. Ed.
Shiel. 15 Jan. 2009. Web. 01 Mar. 2011.
<http://www.medicinenet.com/hemoglobin_a1c_test/article.htm>.
William C.
10 "Diabetes - What Should My Blood Sugar Levels Be? - Diabetes Mellitus, Type 2 Diabetes, Type 1, and
Metabolic Disorders Treatment and Medications on MedicineNet.com." MedicineNet. Ed.
William C.
Shiel. 29 Mar. 2002. Web. 01 Mar. 2011.
<http://www.medicinenet.com/script/main/art.asp?articlekey=17384>.
11. "Product Information." Medtronic Minimed, Inc. Web. 01 Mar. 2011.
<http://www.minimed.com/products/index.html>.
12. Mendosa, David. "GlucoWatch." David Mendosa: A Writer About Diabetes. 31 Oct. 2007. Web.
01 Mar. 2011. <http://www.mendosa.com/glucowatch.htm>.
13. C.T.S. Ching, P. Conolly, Asian Journal of Health and Information Sciences, Vol. 1, No. 4,
pp. 393-410, 2007.
14. A. Ramachandran, et al., A New Non-Invasive Technology to Screen for Dysglycaemia Including Diabetes,
Diab. Res. Clin. Pract., 2010.
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15. Tak S Ching, Patricia Connolly, Simultaneous Transdermal Extraction of Glucose and Lactate from
Human Subjects by Reverse Iontophoresis, International Journal of Nanomedicine, 2008
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16 Kiel. “Near Infrared Spectroscopy. Introduction into the method.” 2004. Web. 04 Apr. 2011.
<http://www.ga-online.org/files/kiel2003/WS_Roos.pdf>
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17. Malin, Stephen F., et al. “Noninvasive Prediction of Glucose by Near-Infrared Diffuse Reflectance
Spectroscopy.” Clinical Chemistry, Vol. 45, No. 9. 1999.
18. "Sensys Medial, Inc – Near-Infreared Spectroscopy." Diabetes Mall. 2010. Web. 03 Apr. 2011.
<http://www.diabetesnet.com/diabetes_technology/meters-monitors/future-metersmonitors/sensys-medical>.
19. Klonoff, David C., et al. “Mid-Infrared Spectroscopy for Noninvasive Glucose Monitoring.” IEEE - The
World's Largest Professional Association for the Advancement of Technology. Apr. 1998. Web. 02 Apr. 2011.
<http://photonicssociety.org/newsletters/apr98/midinfrared.htm>.
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20. "Optiscan, Mid-Range Infrared Technology for the Measurement of Blood Glucose." Diabetes
Mall.
2010. Web. 03 Apr. 2011. <http://www.diabetesnet.com/diabetes_technology/optiscan.php>.
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21. "OptiScanner | Glucose Monitoring." OptiScan Corp. Web. 04 Apr. 2011.
<http://www.optiscancorp.com/tech.html>.
22. Christison GB, MacKenzie HA. “Laser photoacoustic determination
of physiological glucose concentrations in human whole blood.
” Med Biol Eng Comput 1993;31:284 –90.
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23. MacKenzie, Hugh A. et al. “Advances in Photoacoustic Noninvasive Glucose Testing.” Clinical
Chemistry, Vol. 45, No 9. 1999.
24. Waynant, R. W., and V. M. Chenault. "Overview of Non-Invasive Optical Glucose Monitoring
Techniques." IEEE - The World's Largest Professional Association for the Advancement of
Technology. Apr. 1998. Web. 01 Mar. 2011.
<http://www.ieee.org/organizations/pubs/newsletters/leos/apr98/overview.htm