SignificanceGlaucoma, a leading cause of global blindness, disproportionately affects low-income regions due to expensive diagnostic methods. Affordable intraocular pressure (IOP) measurement is crucial for early detection, especially in low- and middle-income countries.AimWe developed a remote photonic IOP biomonitoring method by deep learning of the speckle patterns reflected from an eye sclera stimulated by a sound source. We aimed to achieve precise IOP measurements.ApproachIOP was artificially raised in 24 pig eyeballs, considered similar to human eyes, to apply our biomonitoring method. By deep learning of the speckle pattern videos, we analyzed the data for accurate IOP determination.ResultsOur method demonstrated the possibility of high-precision IOP measurements. Deep learning effectively analyzed the speckle patterns, enabling accurate IOP determination, with the potential for global use.ConclusionsThe novel, affordable, and accurate remote photonic IOP biomonitoring method for glaucoma diagnosis, tested on pig eyes, shows promising results. Leveraging deep learning and speckle pattern analysis, together with the development of a prototype for human eyes testing, could enhance diagnosis and management, particularly in resource-constrained settings worldwide.
SignificanceDiabetes is a prevalent disease worldwide that can cause severe health problems. Accurate blood glucose detection is crucial for diabetes management, and noninvasive methods can be more convenient and less painful than traditional finger-prick methods.AimWe aim to report a noncontact speckle-based blood glucose measurement system that utilizes artificial intelligence (AI) data processing to improve glucose detection accuracy. The study also explores the influence of an alternating current (AC) induced magnetic field on the sensitivity and selectivity of blood glucose detection.ApproachThe proposed blood glucose sensor consists of a digital camera, an AC-generated magnetic field source, a laser illuminating the subject’s finger, and a computer. A magnetic field is applied to the finger, and a camera records the speckle patterns generated by the laser light reflected from the finger. The acquired video data are preprocessed for machine learning (ML) and deep neural networks (DNNs) to classify blood plasma glucose levels. The standard finger-prick method is used as a reference for blood glucose level classification.ResultsThe study found that the noncontact speckle-based blood glucose measurement system with AI data processing allows for the detection of blood plasma glucose levels with high accuracy. The ML approach gives better results than the tested DNNs as the proposed data preprocessing is highly selective and efficient.ConclusionsThe proposed noncontact blood glucose sensing mechanism utilizing AI data processing and a magnetic field can potentially improve glucose detection accuracy, making it more convenient and less painful for patients. The system also allows for inexpensive blood glucose sensing mechanisms and fast blood glucose screening. The results suggest that noninvasive methods can improve blood glucose detection accuracy, which can have significant implications for diabetes management. Investigations involving representative sampling data, including subjects of different ages, gender, race, and health status, could allow for further improvement.
Significance: The ability to perform frequent non-invasive monitoring of glucose in the bloodstream is very applicable for diabetic patients.Aim: We experimentally verified a non-invasive multimode fiber-based technique for sensing glucose concentration in the bloodstream by extracting and analyzing the collected speckle patterns.Approach: The proposed sensor consists of a laser source, digital camera, computer, multimode fiber, and alternating current (AC) generated magnetic field source. The experiments were performed using a covered (with cladding and jacket) and uncovered (without cladding and jacket) multimode fiber touching the skin under a magnetic field and without it. The subject’s finger was placed on a fiber to detect the glucose concentration. The method tracks variations in the speckle patterns due to light interaction with the bloodstream affected by blood glucose.Results: The uncovered fiber placed above the finger under the AC magnetic field (150 G) at 140 Hz was found to have a lock-in amplification role, improving the glucose detection precision. The application of the machine learning algorithms in preprocessed speckle pattern data increase glucose measurement accuracy. Classification of the speckle patterns for uncovered fiber under the AC magnetic field allowed for detection of the blood glucose with high accuracy for all tested subjects compared with other tested configurations.Conclusions: The proposed technique was theoretically analyzed and experimentally validated in this work. The results were verified by the traditional finger-prick method, which was also used for classification as a conventional reference marker of blood glucose levels. The main goal of the proposed technique was to develop a non-invasive, low-cost blood glucose sensor for easy use by humans.
In this presentation we will present two types of sensors for detecting SARS-CoV-2 symptoms. The first part of the presentation will address a contact-free sensor while its operation principle involves illuminating the inspected subject with a laser beam and analyzing with artificial intelligence (AI) based algorithms, the temporal-spatial changes occurring in the back scattered secondary 2D speckle patterns captured through properly defocused optics. The sensing is performed from a distance of several meters away and is applied to different regions of the subject’s body. We demonstrate measurements performed from the chest and then we extract various cardio-pulmonary bio-sign (several simultaneously) including the sounds of subject’s heart and lungs (like a remote stethoscope). We also perform measurements from the sclera and search for anomalies in the random eye movements. From those anomalies we estimate amount of saturated oxygen in the blood stream. All of the above-mentioned bio-parameters could be useful for remote early detection of SARS-CoV-2 symptoms. The AI algorithms are applied not only to extract the various bio-signs but also to perform the bio-medical diagnosis.
In the second part of the presentation, we will present fiber based sensor that is incorporated into textile and clothing and make them a smart-clothing capable via a non-tight contact way to perform sensing of various vital bio-signs (several simultaneously). The bio-parameters to be sensed are related to cardio-pulmonary activity as well as blood-pressure and thus could be associated with early detection of SARS-CoV-2 symptoms. The fiber sensor is based on enhanced multi-mode fiber while at its output an artificial intelligence (AI) based algorithm analyses the temporal-spatial characterizations of the generated dynamic 2D speckle patterns. The fiber sensors are positioned in several locations in the clothing and can perform the bio-measurement from different organs of the wearer and thus allow a comparative measurement which could assist in obtaining more agnostic and more reliable bio-sensing. The AI algorithms are applied not only to extract the various bio-signs but also to perform the bio-medical diagnosis.
KEYWORDS: Optical fibers, Speckle pattern, Sensors, Blood pressure, Algorithm development, Cameras, Detection and tracking algorithms, Modulation, Signal to noise ratio
In this research we present a novel configuration allowing to perform high precision sensing of various vital bio-signs obtained from a fiber-based sensor performing the measurements in a non-tight contact with the skin of the measured subject. We will discuss usage of various types of fibers: single as well as multi-mode. Laser beam is injected into the fiber. In the case of a single mode fiber along the fiber, special artifacts that are breaking the total internal reflection condition, are inserted. Those artifacts are causing to some portion of the injected light to escape the fiber and to interact with the nearby surrounding of the fiber, realizing a smart photonic drip. Changes in the resulted interferencebased intensity at the output of the fiber-sensor is analyzed and associated with various bio-medical signs. In the case of a multi-mode fiber, a detector analyzes the temporal-spatial changes of the 2-D speckle pattern imaged at the tip of the fiber. In both cases the fiber strain, temperature change and vibration associated movements occurring in the proximity of the fiber or in the fiber itself, cause change of the fiber propagating photons phase, polarization and amplitude which leads to temporal-spatial changes in the analyzed speckle pattern or in the resulted interference based intensity measured at the output of the fiber-sensor. After applying proper artificial intelligence (AI) algorithmic, one may correlate those small changes with various vital bio-signs such as heart rate, heart rate variability (HRV), heart sound (phono-cardiogram), respiration rate and sound and even blood pressure.
Corneal thickness (CoT) is an important tool in the evaluation process for several disorders and in the assessment of intraocular pressure. We present a method enabling high-precision measurement of CoT based on secondary speckle tracking and processing of the information by machine-learning (ML) algorithms. The proposed configuration includes capturing by fast camera the laser beam speckle patterns backscattered from the corneal–scleral border, followed by ML processing of the image. The technique was tested on a series of phantoms having different thicknesses as well as in clinical trials on human eyes. The results show high accuracy in determination of eye CoT, and implementation is speedy in comparison with other known measurement methods.
Continuous noninvasive measurement of intraocular pressure (IOP) is an important tool in the evaluation process for glaucoma. We present a methodology enabling high-precision, noncontact, reproducible, and continuous monitoring of IOP based on the value of the damping factor of transitional oscillations obtained at the surface of the eye after terminating its stimulation by a sound wave. The proposed configuration includes projection of a laser beam and usage of a fast camera for analyzing the temporal–spatial variations of the speckle patterns backscattered from the iris or the sclera following the above-mentioned sound waves external stimulation. The methodology was tested on an artificial eye and a carp fish eye under varying pressure as well as on human eyes.
Breast cancer has become a major cause of death among women. The lifetime risk of a woman developing this disease has been established as one in eight. The most useful way to reduce breast cancer death is to treat the disease as early as possible. The existing methods of early diagnostics of breast cancer are mainly based on screening mammography or Magnetic Resonance Imaging (MRI) periodically conducted at medical facilities. In this paper the authors proposing a new approach for simple breast cancer detection. It is based on skin stimulation by sound waves, illuminating it by laser beam and tracking the reflected secondary speckle patterns. As first approach, plastic balls of different sizes were placed under the skin of chicken breast and detected by the proposed method.
Continuous noninvasive measurement of vital bio-signs, such as cardiopulmonary parameters, is an important tool in evaluation of the patient’s physiological condition and health monitoring. On the demand of new enabling technologies, some works have been done in continuous monitoring of blood pressure and pulse wave velocity. In this paper, we introduce two techniques for non-contact sensing of vital bio signs. In the first approach the optical sensor is based on single mode in-fibers Mach-Zehnder interferometer (MZI) to detect heartbeat, respiration and pulse wave velocity (PWV). The introduced interferometer is based on a new implanted scheme. It replaces the conventional MZI realized by inserting of discontinuities in the fiber to break the total internal reflection and scatter/collect light. The proposed fiber sensor was successfully incorporated into shirt to produce smart clothing. The measurements obtained from the smart clothing could be obtained in comfortable manner and there is no need to have an initial calibration or a direct contact between the sensor and the skin of the tested individual. In the second concept we show a remote noncontact blood pulse wave velocity and pressure measurement based on tracking the temporal changes of reflected secondary speckle patterns produced in human skin when illuminated by a laser beams. In both concept experimental validation of the proposed schemes is shown and analyzed.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.