System for real-time detection of cerebral ischemic events using multichannel near-infrared spectroscopy

Abstract

A system for the real-time detection of cerebral ischemic events using multichannel near-infrared spectroscopy, comprising: a head-attachable structural assembly made of a flexible or semi-rigid biocompatible substrate configured to conform to the skull surface of a subject; a plurality of near-infrared light-emitting units embedded in the structure and arranged in a spatially distributed configuration over predefined areas corresponding to brain regions; a plurality of photodetector units arranged at predetermined distances from the respective light-emitting units to define a plurality of measurement channels, each measurement channel configured to receive diffusely reflected near-infrared light from the underlying brain tissue;a signal acquisition unit electrically coupled to the photodetector units and configured to convert received optical signals into corresponding electrical signals, and additionally amplifying, filtering, and digitizing them; a processing unit operationally coupled to the signal acquisition unit and configured to calculate fluctuations in cerebral oxygenation based on the digitized signals and to identify patterns indicative of cerebral ischemic events in real time; and a communication unit configured to transmit processed data and event notifications to an external system.

Description

Technical field of the invention The present invention relates generally to biomedical instruments, neuromonitoring systems, and non-invasive optical sensor technologies, in particular a device-based system for the real-time detection and monitoring of cerebral ischemic events using multichannel near-infrared spectroscopy (NIRS). The invention further relates to a structurally integrated machine with optical sensor hardware, signal acquisition circuits, embedded processing architecture, and analytical computing units for continuous cerebral hemodynamic measurement. Background of the invention Cerebral ischemia, including transient ischemic attacks (TIAs) and ischemic strokes, results from reduced blood flow to brain tissue and can lead to irreversible neurological damage if left untreated. While conventional imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI) provide diagnostic information, their size, cost, and practical limitations make them unsuitable for continuous bedside monitoring. Existing monitoring techniques do not allow for continuous, non-invasive, real-time assessment of cerebral oxygen saturation in different brain regions. Near-infrared spectroscopy (NIRS) has established itself as a promising optical technique for measuring the relative concentrations of oxygenated hemoglobin (HbO2) and deoxygenated hemoglobin (Hb) in biological tissues. However, existing NIRS systems have limitations regarding spatial resolution, insufficient multichannel integration, inadequate noise filtering, and the lack of robust computational models for the early detection of ischemia. Therefore, there is a need for an integrated, instrument-based system capable of acquiring multichannel light signals, performing real-time signal processing, and identifying ischemic features with high sensitivity and specificity. Cerebral ischemia represents a critical group of neurological disorders resulting from insufficient cerebral blood flow and the consequent inadequate supply of oxygen and glucose to brain tissue. These events, such as ischemic stroke, transient ischemic attack (TIA), and hypoxic-ischemic brain injury, are among the most common causes of death and long-term disability worldwide. The pathophysiology of cerebral ischemia involves complex cascades of biochemical and hemodynamic changes, including impaired cerebral autoregulation of blood flow, mitochondrial dysfunction, excitotoxicity, and subsequent neuronal cell death. Early detection of these events is essential for timely therapeutic intervention, such as thrombolysis or mechanical thrombectomy, which significantly improves clinical outcomes.However, continuous and real-time monitoring of cerebral oxygen supply remains a major challenge in both acute and intensive care medicine. The standard clinical diagnostic procedures for cerebral ischemia are primarily based on imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). CT is widely used due to its rapid imaging capabilities and availability in emergency situations, particularly for differentiating between ischemic and hemorrhagic stroke. However, CT has low sensitivity in the early stages of ischemia, as structural changes in brain tissue are not always immediately apparent. MRI, especially diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI), offers higher sensitivity for early ischemic changes and allows visualization of the infarct core and penumbra.Despite these advantages, MRI systems are expensive, require specialized infrastructure, and are unsuitable for continuous bedside monitoring due to their immobility and susceptibility to motion artifacts. PET allows for the quantitative assessment of cerebral metabolism and blood flow, but is impractical for routine monitoring due to radiation exposure, high operating costs, and complex logistics. Transcranial Doppler sonography (TCD) is another technique for assessing cerebral blood flow velocity in the large intracranial arteries. Although TCD is non-invasive and can be used directly at the bedside, it is highly operator-dependent and only partially suitable for directly measuring oxygenation or perfusion at the tissue level. Furthermore, TCD measurements are limited to large vessels and do not provide spatially resolved information about regional cerebral ischemia. Electroencephalography (EEG) has also been investigated for the detection of ischemic changes, as cerebral hypoxia can lead to alterations in electrical activity. However, EEG signals are indirect indicators of ischemia and are affected by numerous confounding factors such as sedation, metabolic disturbances, and artifacts, which limits their specificity and reliability for ischemia detection. Near-infrared spectroscopy (NIRS) has established itself as a promising, non-invasive optical technique for monitoring cerebral oxygenation. It utilizes the different absorption properties of oxygenated and deoxygenated hemoglobin in the near-infrared spectrum. Conventional NIRS systems typically use a limited number of light sources and detectors to measure changes in optical density and estimate the relative hemoglobin concentration. These systems are particularly useful in neonatal care and during surgical procedures for monitoring regional cerebral oxygen saturation. However, traditional NIRS systems often exhibit low spatial resolution due to the limited number of channels and fixed optode configurations.This limits their ability to locate ischemic regions with sufficient precision, especially in cases of focal or dynamically changing ischemia. Another limitation of existing NIRS systems is their susceptibility to noise and signal artifacts. Motion artifacts, ambient light, and physiological disturbances such as heartbeat and respiration can significantly distort the acquired signals. Although various filtering techniques, including bandpass filtering and principal component analysis, have been proposed, these approaches are often insufficient for real-time applications requiring fast and accurate detection. Furthermore, conventional NIRS systems are typically based on simplified models of light propagation in tissue, such as the modified Lambert-Beer law, which assumes homogeneous tissue properties and a constant optical path length. In reality, however, biological tissues exhibit complex scattering and absorption properties, leading to inaccuracies in hemoglobin concentration determination. Multichannel NIRS systems were developed to overcome some of the spatial limitations of conventional configurations. They utilize multiple transmitter-receiver pairs distributed across the scalp, enabling topographic mapping of cerebral oxygenation with improved spatial resolution. However, the increased number of channels introduces additional challenges regarding system complexity, data synchronization, and crosstalk between adjacent channels. Optical crosstalk, in which light from one transmitter is detected by unintended detectors, can lead to erroneous measurements and compromise the reliability of the spatial mapping. Furthermore, integrating multiple channels requires sophisticated hardware design and signal processing techniques to ensure accurate and synchronized data acquisition. Another significant drawback of existing systems lies in their limited capacity for real-time data analysis and decision-making. Most commercially available NIRS devices deliver raw or minimally processed data that must be manually interpreted by clinicians. This not only increases the cognitive load on medical staff but also leads to variability in diagnosis due to subjective interpretations. While some research employs machine learning techniques for automated analysis, these implementations are often limited to offline processing and cannot be integrated into real-time monitoring systems. Furthermore, the performance of such methods depends heavily on the quality and variety of the training data, which may not adequately represent all clinical scenarios. Wearing comfort and ease of use are further important aspects of current monitoring systems. Many existing NIRS devices are bulky, inflexible, and not ergonomically designed for continuous use. Insufficient contact between optical sensors and the scalp can lead to signal degradation and increased susceptibility to movement artifacts. Furthermore, variations in hair density, skin pigmentation, and scalp curvature can affect optical coupling and measurement accuracy. Existing designs often fail to address these practical challenges, limiting their applicability in continuous monitoring scenarios, such as in intensive care units or outpatient settings. Power consumption and thermal management also pose challenges for multi-channel NIRS systems. Operating multiple light sources and high-speed data acquisition circuits can result in significant energy consumption and heat generation. Excessive heat not only impairs device performance but also compromises patient comfort and safety. Current systems often lack efficient energy management strategies and heat dissipation mechanisms, limiting their lifespan and reliability. In addition to hardware limitations, standardized protocols for interpreting NIRS parameters in the context of cerebral ischemia are lacking. The variability of measurement techniques, calibration methods, and data processing procedures leads to inconsistencies between different systems and studies. This lack of standardization hinders the widespread application of NIRS technology in clinical practice and limits its integration into existing healthcare workflows. While significant progress has been made in the development of non-invasive brain monitoring technologies, existing solutions suffer from several critical drawbacks. These include limited spatial resolution, susceptibility to noise and artifacts, a lack of real-time analysis capabilities, ergonomic challenges, and insufficient integration of advanced computing methods. These limitations underscore the need for an improved system that combines robust multi-channel optical sensing with advanced signal processing and real-time analysis, while also addressing practical considerations regarding device design, ease of use, and reliability. Summary of the invention The present invention describes a system in the form of a portable device, consisting of a multi-channel near-infrared spectrometer for the real-time detection of cerebral ischemic events. The system integrates an arrangement of near-infrared light emitters and photodetectors on a head-mounted carrier, a signal acquisition and processing circuit, and a processing unit for performing computational procedures for hemodynamic analysis. The system emits near-infrared light in a predefined wavelength range, typically between 650 nm and 950 nm, and measures the intensity of the diffusely reflected light from brain tissue. By using multiple emitter-detector pairs arranged in spatially distributed channels, the system enables regional mapping of cerebral oxygenation. The processing unit calculates relative changes in hemoglobin concentration using modified Lambert-Beer laws and detects ischemic patterns based on temporal and spatial variations in oxygen profiles. The device also includes a housing adapted to the human scalp, embedded wiring connections, shielding layers to minimize environmental interference, and a communication interface for transmitting processed data to external monitoring systems. The present invention relates to a system for the real-time detection of cerebral ischemic events using multichannel near-infrared spectroscopy. The system is designed as a structurally integrated device that continuously monitors cerebral oxygenation with high temporal resolution and improved spatial specificity. The invention enables the early detection of ischemic conditions by capturing dynamic changes in the concentrations of oxygenated and deoxygenated hemoglobin in different brain regions, thus contributing to timely clinical intervention and improved treatment outcomes. A further objective of the invention is to provide a device with multiple near-infrared light emitters and photodetectors arranged in a multi-channel configuration on a head-worn structure. The spatial distribution of the channels enables improved mapping of regional cerebral hemodynamics. The invention aims to overcome the limitations of the low spatial resolution of conventional systems by enabling the simultaneous acquisition of optical signals from multiple cortical regions, thus allowing precise localization of ischemic zones. A further objective of the invention is to provide a system with a signal acquisition and processing unit that can amplify, filter, and digitize optical signals with high accuracy, thereby largely minimizing noise, motion artifacts, and environmental interference. The invention aims to improve signal integrity through optimized analog input stage circuits and adaptive filtering methods, thereby ensuring the reliable detection of subtle physiological changes associated with ischemia. A further objective of the invention is to provide a processing architecture for the real-time calculation of hemoglobin concentration changes using physiologically relevant models of light propagation in biological tissue, including compensation for scattering effects and path length variations. The invention further aims to implement analytical methods capable of identifying ischemic signatures based on temporal trends, rate-of-change analyses, and spatial correlations across multiple channels. A further objective of the invention is to provide a system for the automated detection and alarming of abnormal cerebral oxygen patterns indicative of ischemia. The invention aims to reduce reliance on manual interpretation by integrating artificial intelligence into the device, thereby enabling rapid and objective decision-making in clinical settings. A further objective of the invention is to provide an ergonomically designed and portable device that ensures stable and consistent optical coupling between sensor elements and the scalp, while simultaneously compensating for variations in head shape and user movements. The invention aims to increase patient comfort and enable long-term monitoring through the use of flexible materials, adjustable fastening mechanisms, and optimized sensor arrangements. A further objective of the invention is to provide a system with integrated communication functions for transmitting processed data and alerts to external monitoring stations or clinical information systems. This enables remote monitoring and integration into existing healthcare workflows. The invention also aims to support real-time data visualization and storage for longitudinal analyses. A further objective of the invention is to provide an energy-efficient system with optimized energy management and thermal regulation, ensuring safe and reliable operation over extended periods without compromising performance or user comfort. The invention aims to address the challenges associated with power consumption and heat dissipation in multi-channel optical sensor systems. A further objective of the invention is to provide a scalable and adaptable architecture that can integrate additional physiological measurement methods such as electroencephalography or cardiovascular monitoring to improve the accuracy and robustness of ischemia detection. The invention further aims to support advanced analytical methods, including machine learning for classification, for improved predictive capability. Overall, the invention aims to provide a comprehensive, non-invasive, real-time monitoring system for the brain that integrates multi-channel optical sensing, advanced signal processing, and intelligent analysis into a single device, thereby overcoming the limitations of existing technologies and enabling effective detection and treatment of ischemic events in the brain. BRIEF DESCRIPTION OF THE IMAGE These and other features, aspects and advantages of the present invention will be better understood if the following detailed description is read with reference to the accompanying drawing, in which the same symbols represent the same parts: Fig. 1 shows a block diagram of a system for real-time detection of cerebral ischemic events using multi-channel near-infrared spectroscopy. Furthermore, those skilled in the art will recognize that the elements in the drawing are simplified and not necessarily drawn to scale. For example, the flowcharts illustrate the process by highlighting the main steps to facilitate understanding of the present disclosure. With regard to the construction of the device, one or more components may be represented in the drawing by conventional symbols. The drawing may show only the specific details relevant to understanding the embodiments of the present disclosure, so as not to clutter the drawing with details that are already apparent to those skilled in the art from the description contained herein. Detailed description of the invention To facilitate understanding of the principles of the invention, reference is made below to the embodiment shown in the drawing, which is described using specific terms. It is understood, however, that this does not limit the scope of protection of the invention. Rather, modifications and further developments of the depicted system, as well as further applications of the inventive principles shown therein, are conceivable, insofar as they would normally occur to a person skilled in the art in the field of the invention. It will be clear to those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not to be understood as a limitation thereof. References to “an aspect”, “another aspect”, or similar phrases in this description mean that a particular feature, structure, or property described in connection with the embodiment is included in at least one embodiment of the present disclosure. Therefore, phrases such as “in one embodiment”, “in another embodiment”, and similar expressions in this description may, but do not necessarily, all refer to the same embodiment. The terms "includes," "comprehensive," or similar expressions denote non-exclusive inclusion. Thus, a procedure or method containing a list of steps does not only include those steps but may also include further steps not explicitly listed or inherent in the procedure or method. Likewise, the statement "includes..." for one or more devices, subsystems, elements, structures, or components, without further limitations, does not preclude the existence of other devices, subsystems, elements, structures, or components. Unless otherwise defined, all technical and scientific terms used herein have the same meanings generally known to those skilled in the art in the field to which this invention belongs. The systems, methods, and examples described herein serve only for illustration and are not to be understood as limiting. Embodiments of the present disclosure are described in detail below with reference to the attached drawing. Fig. 1 shows a block diagram of a system for the real-time detection of cerebral ischemic events using multichannel near-infrared spectroscopy. The system 100 comprises: a head-worn structure (102) made of a flexible or semi-rigid, biocompatible substrate that conforms to the subject's skull surface; several near-infrared light emitters (104) integrated into the structure and spatially distributed in predefined brain regions; and several photodetectors (106) at predetermined distances from the light emitters, forming measurement channels. Each measurement channel receives diffusely reflected near-infrared light from the underlying brain tissue.A signal acquisition unit (108) converts the received optical signals into electrical signals and amplifies, filters, and digitizes them; a processing unit (110) is operationally coupled with the signal acquisition unit and is configured to calculate fluctuations in cerebral oxygen saturation based on the digitized signals and to detect patterns in real time that indicate cerebral ischemic events; and a communication unit (112) is configured to transmit processed data and event notifications to an external system. In one embodiment, each near-infrared light emission unit (104) is configured to emit light at least two discrete wavelengths within a spectral range suitable for distinguishing between oxygenated and deoxygenated hemoglobin, wherein the emission is time-multiplexed to prevent interference between adjacent channels. In one embodiment, the plurality of photodetector units (106) comprises semiconductor-based optical sensors with a spectral sensitivity tuned to the emitted wavelengths, wherein each photodetector unit is additionally connected to an optical shielding arrangement configured to reduce interference from ambient light and optical crosstalk between the channels. In one embodiment, the signal acquisition unit (108) comprises a plurality of transimpedance amplifier circuits, each transimpedance amplifier circuit being configured to convert low-amplitude photocurrent signals into voltage signals with a predefined gain, followed by analog filter circuits configured to attenuate noise components from physiological and environmental sources. In one embodiment, the analog filter circuits comprise a combination of low-pass and high-pass filters configured to isolate frequency bands corresponding to cerebral hemodynamic fluctuations while suppressing motion-related artifacts and network interference. In one embodiment, the signal acquisition unit (108) further comprises an analog-to-digital conversion arrangement configured to sample the filtered signals at a sampling rate sufficient to detect temporal fluctuations in cerebral oxygen supply with high resolution. In one embodiment, the processing unit (110) is configured to determine relative changes in the concentrations of oxygenated and deoxygenated hemoglobin by calculating optical density changes and applying path length correction factors that correspond to the scattering properties of the tissue. In one embodiment, the processing unit (110) is further configured to perform temporal filtering and baseline normalization of the calculated concentration values, with the baseline normalization being continuously updated based on an initial calibration period. In one embodiment, the processing unit (110) is configured to perform an artifact suppression procedure that includes adaptive filtering techniques which dynamically adjust the filter parameters based on detected signal disturbances associated with subject movements or external disturbances. In one embodiment, the processing unit (110) is further configured to generate a spatial representation of the cerebral oxygen supply by aggregating data from the multitude of measurement channels and mapping the aggregated data onto a coordinate system that corresponds to the structural arrangement. The system is implemented entirely with physical hardware components responsible for optical sensing, signal processing, and real-time analysis, without any software-based execution. The head-worn structure consists of a flexible or semi-rigid substrate that mechanically supports embedded near-infrared light emitters and spatially distributed photodetectors. These are positioned to form fixed measurement channels over defined regions of the skull. The light emitters are semiconductor-based optical emitters driven by electronic driver circuits to generate controlled multi-wavelength illumination. The photodetectors are solid-state sensors that generate electrical currents in response to diffusely reflected optical signals from brain tissue. The signal acquisition hardware consists of discrete analog electronic circuits, including transimpedance amplifiers that directly convert the photocurrent into voltage.This is followed by passive and active filter networks consisting of resistors, capacitors, and operational amplifier stages that suppress noise and isolate physiologically relevant frequency components. Analog-to-digital conversion is performed by dedicated converter hardware that samples the processed electrical signals at a defined sampling rate to generate digital signal representations. The processing functionality is implemented using hardware-based signal processing circuits with fixed functions. These circuits perform optical density calculations, hemoglobin concentration derivation, baseline normalization, artifact suppression, and spatial aggregation through dedicated electronic processing units, without requiring software instructions. The present invention relates to a system for the real-time detection of cerebral ischemic events using multi-channel near-infrared spectroscopy. The system's operation is controlled by a sequence of coordinated signal processing, preprocessing, computation, spatial reconstruction, and decision-making processes, all performed by a processing unit. The system is configured to continuously acquire optical signals from multiple measurement channels defined by spatially distributed near-infrared light emitters and associated photodetectors on a head-worn device. Each light emitter is activated sequentially and in a time-controlled manner, so that the emitted near-infrared light penetrates the scalp, skull, and cerebral cortex and is diffusely reflected back to the photodetectors.The photodetectors convert the received optical signals into electrical currents that are proportional to the intensity of the reflected light, thus generating analog raw signals for each measurement channel. The signal acquisition unit receives the analog signals and performs initial signal conditioning using transimpedance amplification. Weak photocurrent signals are converted into voltage signals with controlled amplification. The amplified signals are then subjected to analog filters to suppress noise caused by fluctuations in ambient light, mains interference, and physiological artifacts such as heart pulsations and respiratory cycles. The filtered analog signals are subsequently digitized by an analog-to-digital converter operating at a sampling rate sufficient to capture rapid temporal changes in cerebral hemodynamics. The resulting digital signals are then transmitted to the processing unit for further computer-aided analysis. After receiving the digitized signals, the processing unit performs a preprocessing phase in which baseline correction and normalization are carried out. An initial baseline is established during a calibration interval in which the subject is assumed to be physiologically stable. The system continuously updates this baseline to compensate for gradual fluctuations in signal intensity. The preprocessing phase also includes temporal smoothing and artifact suppression. Adaptive filtering techniques are used to detect and remove signal distortions caused by subject movement or temporary environmental influences. The adaptive filtering process dynamically adjusts the filter coefficients based on the statistical properties of the input signal, thus ensuring the preservation of physiologically relevant variations while minimizing noise. After preprocessing, the processing unit calculates the changes in optical density for each measurement channel by comparing the instantaneous light intensity values ​​with the corresponding baseline values. These changes in optical density reveal variations in light absorption within the tissue and are subsequently used to estimate the relative concentrations of oxygenated and deoxygenated hemoglobin. The estimation process incorporates path length correction parameters that account for the scattering properties of the biological tissue and the effective distance photons travel between the light sources and the photodetectors. The processing unit manages calibration coefficients for each channel to ensure consistency and accuracy in the multichannel configuration. The calculated hemoglobin concentration values ​​are then subjected to temporal analysis to identify trends and rates of change. The processing unit evaluates the temporal evolution of oxygenated and deoxygenated hemoglobin signals over successive time intervals and detects patterns indicative of reduced cerebral blood flow. In particular, the procedure identifies sustained decreases in oxygenated hemoglobin levels that coincide with corresponding increases in deoxygenated hemoglobin levels—characteristic features of ischemic conditions. Furthermore, the processing unit calculates derived parameters such as the rate of oxygenation decline and the duration of abnormal conditions to enhance sensitivity for early ischemic events. In parallel with the temporal analysis, the processing unit spatially aggregates the data from multiple measurement channels to generate a representation of regional cerebral oxygenation. Each measurement channel is assigned a predefined spatial coordinate corresponding to its position on the head-mounted structure. The processing unit integrates the channel-wise data to create a spatial map reflecting the variations in oxygenation across different cortical regions. This spatial mapping process incorporates interpolation techniques to estimate values ​​between measurement points, thus providing a continuous representation of cerebral oxygen distribution. The system also includes a detection logic that evaluates temporal and spatial parameters to determine the presence of a cerebral ischemic event. This logic compares the calculated parameters with predefined thresholds and decision criteria stored in the processing unit. These criteria include absolute thresholds for oxygen saturation, relative changes from baseline, and spatial gradients between adjacent channels. The procedure also considers the persistence of abnormal conditions over a defined period to reduce false positives due to transient fluctuations. If all criteria are met, the processing unit classifies the condition as indicative of a cerebral ischemic event. In an advanced implementation, the processing unit integrates a classification procedure based on previously stored data representing normal and pathological patterns of cerebral oxygenation. This procedure analyzes current measurement data to identify similarities with known ischemic patterns, thereby improving the robustness and accuracy of detection. The classification process is continuously optimized with the acquisition of new data, allowing the system to adapt to individual patient characteristics and changing physiological conditions. Upon detection of a cerebral ischemic event, the processing unit generates an alarm signal, which may include visual, audible, or electronic notifications. This alarm signal is transmitted via the communication unit to external monitoring systems, enabling medical personnel to take immediate action. The communication unit also allows for the continuous transmission of processed data for remote monitoring and analysis. The system operates in continuous monitoring mode, with signal acquisition, preprocessing, calculation, and recognition occurring iteratively in real time. Energy management procedures regulate energy consumption by controlling the lighting units and optimizing processing. Thermal management elements within the system structure dissipate the heat generated by the electronic components, thus ensuring stable operation and a high level of user comfort. The system design ensures consistent optical coupling between the sensor elements and the scalp. Adjustable mounting mechanisms and damping layers provide stable positioning of the light and photodetectors, thus minimizing movement-related artifacts. Optical isolation devices between adjacent measurement channels prevent crosstalk and ensure measurement accuracy. By integrating multi-channel optical sensors, adaptive signal processing, and real-time analysis methods, the system offers a comprehensive solution for the continuous monitoring and early detection of cerebral ischemic events. The technical framework implemented in the processing unit enables the precise characterization of cerebral hemodynamics and the reliable identification of ischemic patterns, thus overcoming the limitations of existing monitoring technologies. The system for the real-time detection of cerebral ischemic events is implemented as a device comprising a head-worn structure. This structure securely positions multiple optical sensor elements over predefined areas of the subject's scalp. The structure consists of a flexible or semi-rigid frame made of biocompatible material, containing multiple mounts for near-infrared light sources and associated photodetectors. The arrangement of these elements defines several measurement channels. Each channel corresponds to a specific emitter-detector pair positioned at a predetermined distance from each other to allow near-infrared light to penetrate the brain tissue. Each light source emits near-infrared radiation at discrete wavelengths, preferably in two- or multi-wavelength configurations, to distinguish between oxygenated and deoxygenated hemoglobin. The photodetectors receive diffusely reflected light and convert optical signals into corresponding electrical signals. The system includes a signal acquisition circuit with transimpedance amplifiers, analog filters, and analog-to-digital converters that amplify, filter, and digitize the acquired signals with high temporal resolution. The digitized signals are transmitted to a processing unit consisting of one or more processors and associated memory. The processing unit is configured to execute instructions for the real-time calculation of changes in optical density and subsequently estimates the concentration changes of HbO2 and Hb using a modified Lambert-Beer law. The calculation incorporates path length correction factors and differential path length coefficients to account for tissue scattering properties. The processing unit also performs temporal filtering and artifact suppression to eliminate motion-induced noise and ambient light interference. Adaptive filtering techniques, including recursive least-squares filtering and wavelet-based noise reduction, are employed to improve signal quality. The system also features a baseline normalization mechanism to continuously recalibrate measurements relative to an initial physiological baseline. Spatial mapping of cerebral oxygenation is achieved by aggregating data from multiple channels and reconstructing a two- or three-dimensional representation of regional oxygen saturation. The processing unit employs pattern recognition techniques to identify ischemic signatures characterized by a sustained decrease in oxygenated hemoglobin, an increase in deoxygenated hemoglobin, and altered hemodynamic response patterns. A detection logic implemented in the processing unit evaluates predefined thresholds and rate-of-change parameters. Upon detection of an ischemic event, the system generates an alarm signal and optionally transmits the event data via a communication interface, which can include wired or wireless transmission protocols such as Bluetooth, WLAN, or cellular networks. The machine also includes an integrated power supply unit that provides a stable power supply to the optical emitters, detectors, and processing components. Integrated thermal management elements dissipate the heat generated during operation, thus ensuring ease of use and the reliability of the device. The system design ensures optimal contact between optical elements and the scalp through adjustable straps, padding layers, and alignment aids. Optical partitions between adjacent channels minimize crosstalk and guarantee measurement accuracy. In an advanced embodiment, the processing unit is additionally configured to implement machine learning-based classification procedures trained on labeled datasets of ischemic and non-ischemic patterns. This improves detection accuracy and enables predictive analytics. The system can also integrate physiological signals such as electroencephalography or heart rate data to increase diagnostic reliability. The present invention relates to biomedical devices and non-invasive neuromonitoring systems, in particular a system for the real-time detection of cerebral ischemic events using multichannel near-infrared spectroscopy. The invention specifically relates to an integrated structure and electronics arrangement comprising optical sensors, a signal acquisition circuit, and a processing unit for the continuous monitoring and analysis of cerebral hemodynamic parameters. Furthermore, the invention relates to computational methods for processing multichannel optical signals to determine changes in the concentrations of oxygenated and deoxygenated hemoglobin, thereby enabling the early detection of ischemic conditions in brain tissue. The drawing and the preceding description illustrate embodiments. Those skilled in the art will recognize that one or more of the described elements can be combined to form a single functional element. Alternatively, certain elements can be divided into several functional elements. Elements of one embodiment can be added to another. For example, the process flows described here can be modified and are not limited to the manner described herein. Furthermore, the actions of a flowchart need not be performed in the sequence shown; nor do all actions necessarily need to be carried out. Actions that do not depend on other actions can be performed in parallel with the other actions. The scope of protection of the embodiments is in no way limited by these specific examples. Numerous variations, whether explicitly stated in the description or not, such as...Differences in structure, dimensions, and materials are possible. The scope of protection of the embodiments is at least as comprehensive as described by the following claims. The advantages, other benefits, and problem solutions have been described above with reference to specific embodiments. However, the advantages, benefits, problem solutions, and any components that can effect or enhance an advantage, benefit, or solution are not to be construed as critical, necessary, or essential features or components of the claims. REFERENCES 100 A system for real-time detection of cerebral ischemic events using multichannel near-infrared spectroscopy. 102 Head-mountable structural assembly. 104 Multiple near-infrared light emission units. 106 Multiple photodetector units. 108 Signal acquisition unit. 110 Processing unit. 112 Communication unit.

Claims

A system for the real-time detection of cerebral ischemic events using multi-channel near-infrared spectroscopy, comprising: a head-attachable structural assembly made of a flexible or semi-rigid biocompatible substrate configured to conform to the skull surface of a subject; a plurality of near-infrared light-emitting units embedded in the structure and arranged in a spatially distributed configuration over predefined areas corresponding to brain regions; a plurality of photodetector units arranged at predetermined distances from the respective light-emitting units to define a plurality of measurement channels, each measurement channel configured to receive diffusely reflected near-infrared light from the underlying brain tissue;a signal acquisition unit electrically coupled to the photodetector units and configured to convert received optical signals into corresponding electrical signals, and additionally amplifying, filtering, and digitizing them; a processing unit operationally coupled to the signal acquisition unit and configured to calculate fluctuations in cerebral oxygenation based on the digitized signals and to identify patterns indicative of cerebral ischemic events in real time; and a communication unit configured to transmit processed data and event notifications to an external system. System according to claim 1, wherein each near-infrared light emitting unit is configured to emit light at least two discrete wavelengths within a spectral range suitable for distinguishing between oxygenated and deoxygenated hemoglobin, and wherein the emission is time-multiplexed to prevent interference between adjacent channels. System according to claim 1, wherein the plurality of photodetector units consists of semiconductor-based optical sensors whose spectral sensitivity is tuned to the emitted wavelengths, and wherein each photodetector unit is further connected to an optical shielding arrangement configured to reduce interference from ambient light and optical crosstalk between the channels. System according to claim 1, wherein the signal acquisition unit comprises a plurality of transimpedance amplifier circuits, each transimpedance amplifier circuit being configured to convert low-amplitude photocurrent signals into voltage signals with a predefined gain, followed by analog filter circuits configured to attenuate noise components of a physiological and environmental nature. System according to claim 4, wherein the analog filter circuits comprise a combination of low-pass and high-pass filters configured to isolate frequency bands corresponding to cerebral hemodynamic fluctuations while suppressing motion-related artifacts and network interference. System according to claim 1, wherein the signal acquisition unit further comprises an analog-to-digital conversion device configured to sample the filtered signals at a sampling rate sufficient to detect temporal fluctuations in cerebral oxygen supply with high resolution. System according to claim 1, wherein the processing unit is configured to determine relative changes in the concentrations of oxygenated and deoxygenated hemoglobin by calculating optical density changes and applying path length correction factors corresponding to the scattering properties of the tissue. System according to claim 7, wherein the processing unit is further configured to perform temporal filtering and baseline normalization of the calculated concentration values, the baseline normalization being continuously updated on the basis of an initial calibration period. System according to claim 1, wherein the processing unit is configured to perform an artifact suppression method comprising adaptive filtering techniques which dynamically adjust the filter parameters on the basis of detected signal disturbances associated with movements of the subject or external disturbances. System according to claim 1, wherein the processing unit is further configured to generate a spatial representation of cerebral oxygenation by aggregating data from the plurality of measurement channels and mapping the aggregated data onto a coordinate system corresponding to the structural arrangement.

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