370 likes | 1.69k Views
Non-Invasive Glucose Measurement. Barbara Deschamp Timothy Ficarra Eric Murray. Overview. Eric VeraLight Scout DS LighTouch Glucose Monitor OrSense NBM-200G Barbara GlucoScope GlucoView Tim GlucoWatch EZ Scan Symphony tCGM. Spectroscopy.
E N D
Non-Invasive Glucose Measurement Barbara Deschamp Timothy Ficarra Eric Murray
Overview • Eric • VeraLight Scout DS • LighTouch Glucose Monitor • OrSense NBM-200G • Barbara • GlucoScope • GlucoView • Tim • GlucoWatch • EZ Scan • Symphony tCGM
Spectroscopy • Study of the interaction of matter and light • Light is focused on some area of the body • Light is absorbed and reflected in different ways • Subcategories include near-infrared, mid-infrared, and photoacoustic spectroscopy. • Detect the presence of glucose by observing the reflectance of light against a sample.
VeraLight, Inc. • Scout DS • Consists of a light source, an optical detector, and spectrometer, all located on an arm-rest.
VeraLight, Inc. • Uses spectroscopy to measure advanced glycation end products (AGE) • Glycation occurs when a protein or lipid is bonded with glucose. • Hyperglycemia from diabetes results in higher cellular glucose levels. • This leads to increased glycation, and increased levels of AGE formation. • Product is only useful for predicting the development of Type 2 diabetes. • May eventually replace the current invasive diabetes screening methods.
LighTouch Medical, Inc. • LighTouch Glucose Monitor • 12 issued patents, more pending. • Projects a specific wavelength of light onto fingertip and detects the wavelength of reflected light. • Designed for daily testing and accuracy equal to finger-stick method. • Clinical trials began in 1999 with Joslin Diabetes Center, Syracuse, New York. • Monitor has been continually redesigned since.
LighTouch Medical, Inc. • Improvements have been made in speed, accuracy, cost, and form-factor. • Currently in the process of getting FTA approval. • Plans on releasing home version six to nine months after approval. • Potential to replace traditional method. • Plans to use their technology for other blood analyte measurement devices.
OrSense Ltd. • NBM-200G Glucose Monitor • Specific version of their NBM-200MP which measures hemoglobin, oximetry, and pulse rate. • Based on proprietary Occlusion spectroscopy technology. • Sensor wraps around finger, applying pressure. • The change in blood dynamics is used in allowing a strong optical response. • 51 patents worldwide, more than 20 pending. • Developed the concept of measuring analytes through occlusion of blood flow, a unique finger sensor, and algorithms to facilitate the measurement.
OrSense Ltd. OrSense NBM-200MP OrSense NBM-200G Image Source: http://www.orsense.com
OrSense Ltd. • NBM-200G currently undergoing clinical trials. • Tested on over 450 subjects over a 24-hour period • “At this stage the NBM-200G glucose monitor is utilized for investigation and market awareness purpose only” Image Source: http://www.orsense.com/?id=815
Overview • Eric • VeraLight Scout DS • LighTouch Glucose Monitor • OrSense NBM-200G • Barbara • GlucoScope • GlucoView • Tim • GlucoWatch • EZ Scan • Symphony tCGM
Glucoscope Monitor • Produced by Visual Pathways Inc • Received federal grant in 2003 under the U.S Department of the Army Medical Research Acquistion Activity • Received a patent December 2004 • Measures the glucose levels in the fluid of the anterior chamber of the eye
Visual Pathways Inc • A vision care diagnostic company • Headquarters in Prescott, Arizona • Developed a prototype in 2003 • GlucoScope Monitor uses infrared light to rapidly measure glucose levels in the eye • The handheld device looks like a small pair of binoculars
GlucoScope https://www.diabetesnet.com/diabetes-technology/meters-monitors/future-meters-monitors/visual-pathways
The Human Eye • The cornea and a lens form the anterior chamber • The anterior is also comprised of the iris and the aqueous humor
GlucoScope • Glucose concentration in the bloodstream is directly correlated to the concentration in the aqueous humor • Variation in the glucose concentration will cause variations in its index of refraction • The refractive index can be measured by interferometry
Interferometry • Two beams are directed into the eye and caused to interfere • The interference produces a fringe pattern (bright and dark lines) • The pattern is analyzed and the index of refraction of the eye is determined • The glucose concentrations is then determined • The glucose level in the blood can be determined from this information
Benefits of GlucoScope • Handheld • Portable • Digital readout
Drawbacks • Still in the research and development phase • Not commercially available
Glucoview • Produced by Sentek Group Inc • Licensed from the University of Pittsburg • Disposable contact lens which changes color according to glucose levels in tears • Uses a Crystalline Colloidal Array Technology • A red shift indicates hyperglycemia • A purple shift indicates hypoglycemia
Crystalline Colloidal Array (CCA)Technology • When the CCA is polymerized within a hydrogel PCCA , the PCCA optically reports volume changes experienced by the hydrogel • This is because the observed diffraction wavelength is directly related to the spacing between lattice planes
Crystalline Colloidal Array • The CCAs are brightly colored because they diffract visible light due to Bragg’s diffraction • nλ = 2dsinθ • where, • n is an integer • λ = wavelength of the incident wave • d is the spacing • Bragg diffraction depends on the refractive index of the system and the spacing between the diffracting planes
Benefits of Glucoview • It is non-invasive (no finger pricks) • It requires no instrumentation( to collect fluids or to analyze results) • Provides easily measurable, quantitative results • It is low-cost • Continuous monitoring • Helpful for caretakers of children and elderly
Drawbacks • Necessary to wear contact lenses (most diabetics have vision problems) • Does not collect data for future analysis
Overview • Eric • VeraLight Scout DS • LighTouch Glucose Monitor • OrSense NBM-200G • Barbara • GlucoScope • GlucoView • Tim • GlucoWatch • EZ Scan • Symphony tCGM
Reverse Iontophoresis • 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
GlucoWatch • First commercially available non-invasive glucose measurement technique • Continuous monitoring • Requires blood test for calibration • Suffers inaccuracy in detecting hypoglycemia • Discontinued by Animas Corporation in 2007
EZ Scan • 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
Symphony tCGM System • Transdermal Continuous glucose monitoring • Real time • Biosensor broadcasts wirelessly to a monitoring tool • No calibration • Uses a proprietary skin permeation device - Prelude • Improves effectiveness of reverse iontophoresis Image source: www.echotx.com
Prelude SkinPrep System • Improves permeability of skin for reverse iontophoresis • Tool removes the outmost layer of epidermis (stratum corneum) • Uses feedback control algorithm to prevent damage • .01mm in thickness comprised of dead skin Image source: www.echotx.com
Summary • Spectroscopy and Reverse Iontophoresis • Viable solutions for Non-Invasive Glucose Measurement • Symphony tCGM is one of the most viable candidates • Barbara maintains that the GlucoView will ultimately win