Falls are a major risk for the elderly people living independently. Rapid detection of fall events can reduce the rate of mortality and raise the chances to survive the event and return to ...independent living. In the last two decades, several technological solutions for detection of falls were published, but most of them suffer from critical limitations. In this paper, we present a proof of concept to an automatic fall detection system for elderly people. The system is based on floor vibration and sound sensing, and uses signal processing and pattern recognition algorithm to discriminate between fall events and other events. The classification is based on special features like shock response spectrum and mel frequency ceptral coefficients. For the simulation of human falls, we have used a human mimicking doll: ldquoRescue Randy.rdquo The proposed solution is unique, reliable, and does not require the person to wear anything. It is designed to detect fall events in critical cases in which the person is unconscious or in a stress condition. From the preliminary research, the proposed system can detect human mimicking dolls falls with a sensitivity of 97.5% and specificity of 98.6%.
Solid malignant tumors are one of the leading causes of death worldwide. Many times complete removal is not possible and alternative methods such as focused hyperthermia are used. Precise control of ...the hyperthermia process is imperative for the successful application of such treatment. To that end, this research presents a fast method that enables the estimation of deep tissue heat distribution by capturing and processing the transient temperature at the boundary based on a bio-heat transfer model. The theoretical model is rigorously developed and thoroughly validated by a series of experiments. A 10-fold improvement is demonstrated in resolution and visibility on tissue mimicking phantoms. The inverse problem is demonstrated as well with a successful application of the model for imaging deep-tissue embedded heat sources. Thereby, allowing the physician then ability to dynamically evaluate the hyperthermia treatment efficiency in real time.
We propose a nanoparticles‐based system for the early detection of tumors, treatment under real‐time feedback, and monitoring. The building blocks of the system comprise a few modalities that are ...integrated into one powerful system which can operate at the patient's bedside in an outpatient clinic setting. The method relies on the unique characteristics of superparamagnetic nanoparticles. It takes advantage of their ability to produce acoustical signals under alternating magnetic fields (AMFs) and to produce heat under these same AMFs with different parameters. It utilizes the nanoparticles' coating for specific binding. The manuscript describes the various parts of this method for localization, source separation, confined heat elevation, triggering of cell death, and monitoring the response to treatment through fluorescence signaling. The entire system continues to evolve into a minimally invasive trans‐endoscopic set‐up.
This article is categorized under:
Diagnostic Tools > In Vivo Nanodiagnostics and Imaging
Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease
Proposed multi modal theranostic system concept.
Abstract Background Assessments of gaze direction (eye movements), pupil size, and the pupillary light reflex (PLR) are critical for neurological examination and neuroscience research and constitute ...a powerful tool in diverse clinical settings ranging from critical care through endocrinology and drug addiction to cardiology and psychiatry. However, current bedside pupillometry is typically intermittent, qualitative, manual, and limited to open-eye cases, restricting its use in sleep medicine, anesthesia, and intensive care. Methods We combined short-wave infrared (SWIR, ~0.9-1.7μm) imaging with image processing algorithms to perform rapid (~30 ms) pupillometry and eye tracking behind closed eyelids. Forty-three healthy volunteers participated in two experiments with PLR evoked by visible light stimuli or directing eye movements towards screen targets. Imaging was performed simultaneously on one eye closed, and the other open eye serving as ground truth. Data analysis was performed with a custom approach quantifying changes in brightness around the pupil area or with a deep learning U-NET-based procedure. Results Here we show that analysis of SWIR imaging data can successfully measure stimulus-evoked PLR in closed-eye conditions, revealing PLR events in single trials and significant PLRs in nearly all individual subjects, as well as estimating gaze direction. The neural net-based analysis could successfully use closed-eye SWIR data to recreate estimates of open-eye images and assess pupil size. Conclusions Continuous touchless monitoring of rapid dynamics in pupil size and gaze direction through closed eyes paves the way for developing devices with wide-ranging applications, fulfilling long-standing goals in clinical and research fields.
...the pathogenic process in this stage already induces measurable changes in the brain, in the cerebrospinal fluid (CSF), and in the blood. ...diagnostic tools for early detection of the disease, ...based on these pathological expressions, may have a significant advantage. ...these probes are still under development and are not commercially available, off the shelf products, hence could not be obtained. ...we decided to test our method and verify the accuracy of the concentration ratio estimation using two fluorescent probes that may be purchased easily. The shaving was performed both for the subcutaneous tubes and the abdomen tubes. Since the fluorescence intensity ratio was calculated, and it is assumed that the absorption and emission spectra of the fur is almost flat in the used wavelengths, the shaving should not affect the accuracy of the results. ...there are some differences in the absorption and scattering coefficients between the wavelengths used for the excitation of the two fluorophores, and therefore the errors in the concentration ratio estimation increase with an increase in the tissue thickness. Since the abdomen tubes have thicker overlying tissue than the subcutaneous tubes, the inaccuracy that results from not taking into account photon propagation attenuation has a higher effect, causing bigger errors.
Abstract This work describes the utilization of tumor-specific magnetic nanoparticles together with an alternating magnetic field as a means to thermally mark a tumor so as to detect it using a ...thermal imaging system. Experiments were conducted using an in vitro tissue model, an inductive heating system, and an infrared camera. The thermal images, recorded by the infrared camera during the experiments, were analyzed using an algorithm that was developed as part of this work. The results show that small tumor phantoms (diameter of 0.5 mm) that were embedded under the surface of the tissue phantom (up to 14 mm below the surface) can be detected and located, indicating that the proposed method could potentially offer considerable advantages over conventional thermography and other methods for cancer early detection. Nevertheless, several issues should be clarified in future studies before the method can be offered for clinical use. From the Clinical Editor Tumor-specific magnetic nanoparticles exposed to an alternating magnetic field provide a method to thermally mark a tumor for detection using thermal imaging systems. In-vitro tissue model experiments demonstrated that tumor phantoms of 0.5mm up to 14mm below the surface can be detected and located, indicating that the proposed method could offer considerable advantages over conventional thermography.
Partial aperture imaging is a combination of two different techniques; coded aperture imaging and imaging through an aperture that is only a part of the complete disk, commonly used as the aperture ...of most imaging systems. In the present study, the partial aperture is a ring where the imaging through this aperture resolves small details of the observed scene similarly to the full disk aperture with the same diameter. However, unlike the full aperture, the annular aperture enables using the inner area of the ring for other applications. In this study, we consider the implementation of this special aperture in medical imaging instruments, such as endoscopes, for imaging internal cavities in general and of the human body in particular. By using this annular aperture, it is possible to transfer through the internal open circle of the ring other elements such as surgical tools, fibers and illumination devices. In the proposed configuration, light originated from a source point passes through an annular coded aperture and creates a sparse, randomly distributed, intensity dot pattern on the camera plane. A combination of the dot patterns, each one recorded only once, is used as the point spread hologram of the imaging system. The image is reconstructed digitally by cross correlation between the object intensity response and the point spread hologram.
Abstract Magnetoacoustic detection is a new method for the noninvasive, early detection of cancer. It uses specific superparamagnetic nanoparticles (NPs) that bind to tumor sites together with ...magnetic excitation and acoustic detection of the tumor-NPs complex. This work tests the feasibility of such method theoretically and experimentally. An extensive analytic model has been developed that shows an ability to detect small tumors, a few centimeters deep inside the tissue. A series of experiments were conducted to validate the theoretical model. The performance of specially designed solenoids was measured, and the detection of the tumor presence in phantom was demonstrated. Experimental results agree well with the theoretical calculations, providing preliminary proof of concept. We demonstrate the ability to detect a 5-mm diameter spherical tumor located 3 cm deep. Instrumentation and measurements are inexpensive and accurate. The accuracy, speed, and costs of this method show the potential for early detection of cancer. From the Clinical Editor A sensitive and cost effective magentoacoustic tumor detection method is presented in this paper using superparamagnetic nanoparticles. The method is demonstrated in a phantom by detecting a 5-mm diameter spherical tumor located 3 cm deep.
Mid–infrared laser applications in medicine and biology Waynant, Ronald W.; Ilev, Ilko K.; Gannot, Israel
Philosophical transactions of the Royal Society of London. Series A: Mathematical, physical, and engineering sciences,
03/2001, Volume:
359, Issue:
1780
Journal Article
Peer reviewed
The mid-infrared (mid-IR) should be a fruitful area for medical research and instrumentation since this is the region where the most identifiable molecular molecules absorb and radiate. Due to the ...unique specificity of a biological molecule's spectrum in the mid-IR, semiconductor lasers in the mid-IR have a unique advantage over ultraviolet and visible or near-IR lasers. Small room-temperature laser diodes can be used in small hand-held, portable, and hopefully inexpensive, medical devices for rapid measurement, possibly in patient-operated home-care devices. Since the mid-IR radiation can be connected with otherwise invisible chemical processes, it becomes possible to watch the biochemical processes of life reveal themselves. Until recently, work in this region had been handicapped by lack of sources, detectors and optical materials, but this is changing, as this conference shows, and important new directions lie ahead.
Purpose:
Thermography is a potentially useful method for tumor progress monitoring since it is noninvasive, nonradiative, low‐cost, and rapid. Perfusion and metabolism are dominant factors for ...determining tumor temperature difference and are also correlated to the tumor's growth rate. Therefore, estimating them from the tumor thermal image can be a very useful tumor monitoring method, since thermal changes occur before physical changes. The goal of this work was to study the effect of tumor state on the thermal image in different tumor types, using simulations and measurements.
Methods:
Simulated tumor models, representing flat and extruding tumors, typical to transplantable and natural tumors, respectively, were simulated and the effects of tumor metabolism and perfusion on the temperature difference were analyzed. Data regarding tumor size and measured temperature differences were obtained from the literature, discussing five types of transplantable tumors in mice and rats. The growth rates of all tumors were calculated by fitting tumor size measurements to a tumor growth model and were used as an indicator to tumor aggressiveness. Tumor temperature difference was calculated by taking the effect of its extruding shape into account, according to a previously published method. Tumor state was estimated from the normalized temperature differences using simulations and compared to the calculated aggressiveness rates. Computational models of human breast cancers, both in round and flat breast models, were recreated using a finite‐element‐method heat transfer simulation. Tumor size and state were simulated according to the results obtained from the animal tumor analysis, representing two different tumor aggressiveness levels. The calculated temperature difference as a function of tumor size was calculated for each test case.
Results:
Perfusion was shown to be highly dominant in determining the tumor's temperature difference. Since both metabolism and perfusion were shown to have a linear effect on the temperature difference, a conversion value was defined between them. The analysis of the animal experimental results showed correlations between tumor aggressiveness and the following factors: the normalized temperature difference, the estimated tumor state, and the temperature difference change rate. The simulated human breast cancer models analysis showed highly varying temperature differences between the simulated models. Although for each model there is a clear difference between the temperature differences of the test cases simulated, the large differences between the results might make tumor state estimation difficult. However, reviewing the gradient of the tumor temperature change as a function of tumor size showed that the ratio between the gradients of both test cases was similar for all models. Therefore, the effect of model errors and differences in the simulated tissue structure and properties and the environmental conditions between the different models, can be mitigated. This pattern may be used to estimate tumor state in in vivo experiments.
Conclusions:
Continuous monitoring of tumor temperature difference produces valuable information on tumor state and aggressiveness that can be used both in the clinic and in the laboratory. Monitoring can be either performed on a single image, or continuous on multiple images, revealing changes in tumor state.
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