Abstract: A cardiovascular monitoring system includes a first monitoring device configured to couple to a first body part of a subject and a second monitoring device configured to couple to a second body part of the subject. The first monitoring device is configured to measure a first cardiovascular signal and a first motion signal at the first body part, and the second monitoring device is configured to measure a second cardiovascular signal and a second motion signal at the second body part. A controller of the system receives the first and second cardiovascular signals and the first and second motion signals and filters the first and second cardiovascular signals by removing spectral components that correspond to spectral components of the first and second motion signals. Based on a correlated spectral component that is present in both the filtered first and second cardiovascular signals, the system determines cardiovascular information of the subject.

Abstract: The present disclosure generally relates to logging health-related events and for health-related coaching. In some embodiments, an event is logged by associating an action with a specific time and a user sentiment. In some embodiments, an event challenge, associated with a log entry, is transmitted to an external electronic device.

Abstract: Systems and methods for promoting sexual well-being in males and in some cases for treating erectile dysfunction and, more particularly, to such systems that use shock waves delivered to tissue.

Abstract: Systems and methods are disclosed for assessing organ and/or tissue transplantation by estimating blood flow through a virtual transplant model by receiving a patient-specific anatomical model of the intended transplant recipient; receiving a patient-specific anatomical model of the intended transplant donor, the model including the vasculature of the organ or tissue that is intended to be transplanted to the recipient; constructing a unified model of the connected system post transplantation, the connected system including the transplanted organ or tissue from the intended transplant donor and the vascular system of the intended transplant recipient; receiving one or more blood flow characteristics of the connected system; assessing the suitability for an actual organ or tissue transplantation using the received blood flow characteristics; and outputting the assessment into an electronic storage medium or display.

Abstract: Interferometric speckle visibility spectroscopy methods, systems, and non-transitory computer readable media for recovering sample speckle field data or a speckle field pattern from an off-axis interferogram recorded by one or more sensors over an exposure time and determining sample dynamics of a sample being analyzed from speckle statistics of the speckle field data or the speckle field pattern.

Abstract: Devices and methods for vascular navigation, assessment and/or diagnosis are described which determine the location of the tip of a vascular catheter using the introduction of a medium with a measurable parameter (e.g., temperature, light reflection, sound reflection, etc.) and sensing and measuring the measurable parameter as the catheter is advanced. Measurements of the parameter are tracked over time, recorded and analyzed. The value of the parameter and/or the shape of the parameter value vs. time curve may be used in the analysis. For example, curve amplitude, variability, standard deviation, slope, etc. may be used in the analysis of catheter location.

Abstract: A method of planarizing three dimensional data of a brain implemented by a computer according to an embodiment of the present disclosure includes acquiring a three-dimensional model of the brain scanned by a scanning device, the three-dimensional model including the three-dimensional data of the brain, and mapping, in the computer, the three-dimensional model onto a circle in an area-preserving manner to form an area-preserving map. The method can convert a three-dimensional brain model into a circle or unit disc on a two-dimensional plane so that the brain model can be compared with a reference brain model, and a doctor can judge the position and degree of a brain lesion more accurately.

Abstract: Embodiments of the present disclosure relate to implantable medical devices (IMDs). In an exemplary embodiment, an IMD comprises: a housing including a plurality of feedthroughs extending through the housing, a first electrode, a second electrode, and a biocompatible circuit board disposed around an outer surface of the housing. The biocompatible circuit board comprising a plurality of traces, wherein a first trace of the plurality of traces is coupled to the first electrode and a first feedthrough of the plurality of feedthroughs, and a second trace of the plurality of traces is coupled to the first electrode and a second feedthrough of the plurality of feedthroughs.

Abstract: Systems and methods are disclosed for determining blood flow characteristics of a patient. One method includes: receiving, in an electronic storage medium, patient-specific image data of at least a portion of vasculature of the patient having geometric features at one or more points; generating a patient-specific reduced order model from the received image data, the patient-specific reduced order model comprising estimates of impedance values and a simplification of the geometric features at the one or more points of the vasculature of the patient; creating a feature vector comprising the estimates of impedance values and geometric features for each of the one or more points of the patient-specific reduced order model; and determining blood flow characteristics at the one or more points of the patient-specific reduced order model using a machine learning algorithm trained to predict blood flow characteristics based on the created feature vectors at the one or more points.

Abstract: Disclosed herein are systems and methods for mitigating the risk of insulin stacking in automated insulin delivery systems. In AID systems configured to both automatically calculate insulin delivery based on glucose levels and receive manual programming of meal boluses configured to counteract carbohydrates in a meal, insulin stacking can result if the system automatically increases insulin delivery based on a rise in glucose levels in response to consumption of a meal and the user later programs a meal bolus for the meal. The risk of such double dosing is mitigated by the systems and methods disclosed herein by enabling the system to account for recent automated insulin increases when a meal bolus is programmed.

Abstract: The present disclosure may provide a method for perfusion analysis. The method may include: obtaining a plurality of scan images corresponding to a plurality of time points; obtaining a plurality of time-density discrete points based on the plurality of scan images; determining an initial time-density curve based on the plurality of time-density discrete points, the initial time-density curve indicating a density variation of a contrast agent in an organ or tissue over time, the organ or tissue corresponding to a pixel or voxel in the plurality of scan images; obtaining a first perfusion model; determining a first perfusion parameter based on the first perfusion model and the initial time-density curve; obtaining a second perfusion model; and determining a second perfusion parameter based on the second perfusion model and the first perfusion parameter.

Abstract: The present disclosure discloses a cerebral perfusion state classification apparatus, method and device, and a model training apparatus. In the apparatus, a transceiver module is used for receiving physiological feature data from different data collection devices; and a processor is used for extracting physiological features from the physiological feature data; inputting the physiological features into a random forest model to cause a plurality of decision-making trees in the random forest model to predict a cerebral perfusion state type corresponding to the physiological features; and classifying a cerebral perfusion state based on the cerebral perfusion state type corresponding to the physiological features.

Abstract: A flexible head probe and modular head probe system that includes an optical functional near-infrared spectroscopy (fNIRS) system and integrated position sensor. The head probe and modular head probe system determines physiological data based upon the optical information gathered by the fNIRS system and gathers motion and position data from the position sensor. The physiological data and motion and position data are combined to permit topographical and tomographic analyses of a user's brain tissue.

Abstract: Mechanisms are provided for training a hybrid machine learning (ML) computer model to simulate a biophysical system of a patient and predict patient classifications based on results of simulating the biophysical system. A mechanistic model is executed to generate a training dataset. A surrogate ML model is trained to replicate logic of the mechanistic computer model and generate patient feature outputs based on surrogate ML model input parameters. A transformation ML model is trained to transform patient feature outputs of the surrogate ML model into a distribution of patient features. A generative ML model is trained to encode samples from a uniform distribution of input patient data into mechanistic model parameter inputs that are coherent to the target distribution of patient features and are input to the surrogate ML model. Input patient data for a patient is processed through the ML models to predict a patient classification for the patient.

Abstract: Embodiments include a system for determining cardiovascular information for a patient with coronary artery disease. The system may include at least one computer system configured to receive patient-specific data regarding a geometry of the patient's heart and create a model representing at least a portion of the patient's heart based on the patient-specific data. The at least one computer system may be further configured to create, for a given level of physical activity, a physics-based model of blood flow through the patient's heart simulated during a selected level of physical activity; determine and normalize one or more values of at least one blood flow characteristic within the patient's heart during the simulated level of physical activity; and compare the one or more normalized values of the at least one blood flow characteristic to a threshold to determine whether the level of physical activity exceeds an acceptable level of risk.

Abstract: The invention relates to a blood treatment device having an extracorporeal blood circuit which comprises an arterial line, a blood pump, a blood treatment unit and a venous line, wherein the arterial and venous lines can be connected to a blood vessel of a patient, and wherein the blood treatment device has an evaluation and control unit, wherein the evaluation and control unit is configured to carry out the following steps: (a1) determining the blood recirculation in a blood vessel of the patient connected to the extracorporeal blood circuit; and (b) calculating the blood flow in the blood vessel using the blood recirculation determined in accordance with (a1) and using a provided value or a value likewise previously determined for the cardiac output of the patient.

Abstract: A system comprising a plurality of electrodes adapted to measure bio impedance measurements using electrical currents passing in a target thorax area of a target therebetween during a learning phase, at least one radiofrequency (RF) sensor adapted to measure RF interaction measurements of RF radiation interacting with the target thorax area during the learning phase, and at least one processor adapted to: calculate calibration function according to the bio impedance measurements and the RF interaction measurements, and determine a target thorax area value by adjusting subsequent bio impedance measurements using subsequent electrical currents passing in the target thorax area during an operational learning phase using the calibration function.

Abstract: Devices, systems and methods for controlling the temperature of all or part of the body of a human or animal subject.

Abstract: A machine learning system may automatically produce classifier algorithms and configuration parameters by selecting them into a set of predetermined unitary algorithms and associated parametrization values. Multiple digital representations of input object items may be produced by varying the position and orientation of the object to be classified and/or of the sensor to capture a digital representation of the object, and/or by varying a physical environment parameter which changes the digital representation capture of the object by the sensor. A robot arm or a conveyor may vary the object and/or the sensor positions and orientations. The machine learning system may employ generic programming to facilitate the production of classifiers suitable for the classification of multiple digital representations of input object items.

Abstract: A medical image processing apparatus according to an embodiment includes processing circuitry. The processing circuitry acquires image data including image data of a blood vessel of a subject. The processing circuitry performs analysis related to the blood vessel by using the image data, and specifies a region of interest in the blood vessel based on a result of the analysis. The processing circuitry performs fluid analysis on a region other than the region of interest at a first accuracy, and performs fluid analysis on the region of interest at a second accuracy that is higher than the first accuracy.

Abstract: A time-series morphology index and a time-series shape deformation index of the analysis target region on a time-series medical image are calculated by image processing. A dynamical model of a structural fluid analysis of the analysis target region is temporarily structured, based on the time-series morphology index, the time-series shape deformation index, and the time-series medical image. A latent variable of the identification region is identified so that at least one of a prediction value of a blood vessel morphology index and a blood flow volume index based on the temporarily structured dynamical model match with at least one of an observation value of the blood vessel morphology index and the blood flow volume index measured.

Abstract: An earpiece module includes a physiological sensor, an external energy sensor, a transceiver, a communication module, a data storage component, and a power source. The communication module includes a microphone, a speaker, and a signal processor. The signal processor processes audio information received from a remote source via the transceiver and communicates the processed audio information to a subject via the speaker. The signal processor processes information in real time from the physiological sensor and the external energy sensor, and the signal processor provides biofeedback to the subject based on signals produced by the physiological sensor. The data storage component includes a plurality of algorithms. At least one algorithm focuses processing resources on extracting physiological information from the physiological sensor, at least one algorithm is configured to be modified or uploaded wirelessly via the transceiver, and at least one algorithm is a compression/decompression (CODEC) algorithm.

Abstract: Interferometric speckle visibility spectroscopy methods, systems, and non-transitory computer readable media for recovering sample speckle field data or a speckle field pattern from an off-axis interferogram recorded by one or more sensors over an exposure time and determining sample dynamics of a sample being analyzed from speckle statistics of the speckle field data or the speckle field pattern.

Abstract: A biological information processing apparatus according to an embodiment of the present technology is provided with a sphygmographic sensor unit, a plurality of calculation units, and an output unit. The sphygmographic sensor unit outputs a pulse wave signal. The plurality of calculation units respectively calculate heart rate candidate information with a reliability on a basis of the output pulse wave signal. The output unit outputs heart rate information on a basis of the heart rate candidate information and the reliability thereof calculated by each of the plurality of calculation units.

Abstract: An improved skin blood flow measurement apparatus consists of a chassis with an antenna connected with the chassis such that the antenna directs RF energy at an area of a skin surface below the chassis. A temperature sensor is also connected with the chassis such that the temperature sensor is held in fixed relation to the antenna and such that the temperature sensor is also directed to the same said area of a skin surface below the chassis for measurement of temperature of the area and further where the temperature sensor does not contact the skin surface and where the chassis supports the antenna and the temperature sensor in fixed relation to the area.

Abstract: The present disclosure provides an operating method of a system for analyzing brain tissue based on computerized tomographic imaging, and the operation method includes steps as follows. A computed tomography image of a subject is aligned to a predetermined standard brain space image, to obtain a first normalized test computed tomography image. A voxel contrast of the first normalized test computed tomography image is enhanced to obtain an enhanced first normalized test computed tomography image. The enhanced first normalized test computed tomography image is aligned to an average computed tomographic image of a control group to obtain a second normalized test computed tomography image. An analysis based on the second normalized test computed tomography image and a plurality of computerized tomographic images of the control group is performed to obtain a t-score map.

Abstract: An apparatus for obtaining bio-information may include a pulse wave sensor including a light source and a detector. The light source is configured to emit multi-wavelength light to an object of interest and the detector is configured to detect light reflected from the object. In addition, the apparatus may include a processor configured to obtain a change in volume of a blood vessel based on one or more of quantity of detected multi-wavelength light and absorbance coefficients of respective wavelengths of the multi-wavelength light and obtain bio-information based on the measured change in volume of the blood vessel.

Abstract: A dynamic image analysis apparatus includes a hardware processor that acquires an X-ray dynamic image including continuous frame images acquired by continuously capturing a living body having a heartbeat in time series; performs logarithmic conversion for a pixel value of the acquired X-ray dynamic image to create a logarithmically converted image; sets, as a reference frame image, one frame image based on a heartbeat phase in at least one of the X-ray dynamic image and the logarithmically converted image; calculates (i) a difference or ratio between the X-ray dynamic image as the reference frame image and the X-ray dynamic image as a comparative frame image which is another frame image or (ii) a difference or ratio between the logarithmically converted image as the reference frame image and the logarithmically converted image as the comparative frame image; and generates a blood flow analysis image.

Abstract: A sensor probe has a sensor unit which is embedded in a sheath member which is suturable. The sheath member allows the sensor unit to be sutured and secured to any tissue even in a wet or moist environment. The sensor probe in accordance with the present invention is particularly useful as an intraoral sensor probe for measuring oxygen saturation of a flap tissue inside the oral cavity.

Abstract: In a simulation method according to the present invention, when performing a blood flow simulation by coupling a CFD model and an LPM model, a blood flow simulation for the CFD model is performed under a set initial condition and a boundary condition, a blood flow rate Qi for each outlet and a total outflow blood flow Qtot_cfd of the CFD model are calculated by a blood flow simulation, the microvascular bed parameters of the LPM model are updated using the blood flow rate for each outlet and the total outflow blood flow of the CFD model, the boundary condition of an outlet of the CFD model is updated using the updated LPM model, and the simulation is repeatedly performed until a convergence condition of the blood flow simulation for the CFD model is satisfied, thereby calculating blood flow information for the three-dimensional blood vessel model.

Abstract: In an example, the eyewear includes an optical element, electronic components, and a support structure configured to support the optical element and the electronic components. The support structure defines a region for receiving at least a portion of a head of a user. The eyewear also includes a biometric sensor coupled to the electronic components and supported by the support structure. The biometric sensor is attached to the support structure and positioned to detect, in the region, a biometric signal representative of a biometric of the user for processing by the electronic components.

Abstract: A biological analysis device includes a blood vessel calculation unit that calculates a blood vessel index related to a blood vessel of a biological body in accordance with a blood mass integration value obtained by integrating blood mass indexes relate to a blood mass of the biological body during an integration period and a blood flow integration value obtained by integrating blood flow indexes related to a blood flow of the biological body during the integration period.

Abstract: An electronic device includes a translucent layer that forms a portion of an exterior of the electronic device, an opaque material positioned on the translucent layer that defines micro-perforations, and a processing unit operable to determine information about a user via the translucent layer. The processing unit may be operable to determine the information by transmitting optical energy through a first set of the micro-perforations into a body part of the user, receiving a reflected portion of the optical energy from the body part of the user through a second set of the micro-perforations, and analyzing the reflected portion of the optical energy.

Abstract: A system for monitoring a user includes a garment configured to be placed on a foot of the user, a cover coupled to the garment, and a sensor arrangement between the garment and the cover, wherein the sensor arrangement comprises at least one temperature sensor to measure at least one temperature on the foot of the user. A method for making a system for monitoring a user includes forming a sensor arrangement including at least one sensor lead coupled to a temperature sensor, positioning at least a portion of the sensor arrangement on a garment configured to be placed on a foot of the user, and enclosing at least the portion of the sensor arrangement between the garment and a cover.

Abstract: Computational methods are used to create cardiovascular simulations having desired hemodynamic features. Cardiovascular modeling methods produce descriptions of blood flow and pressure in the heart and vascular networks. Numerical methods optimize and solve nonlinear equations to find parameter values that result in desired hemodynamic characteristics including related flow and pressure at various locations in the cardiovascular system, movements of soft tissues, and changes for different physiological states. The modeling methods employ simplified models to approximate the behavior of more complex models with the goal of to reducing computational expense. The user describes the desired features of the final cardiovascular simulation and provides minimal input, and the system automates the search for the final patient-specific cardiovascular model.

Abstract: Devices, systems, and methods of the present disclosure are directed to accurate and non-invasive assessments of anatomic vessels (e.g., the internal jugular vein (IJV)) of vertebrates. For example, a piezoelectric crystal may generate a signal and receive a pulse echo of the signal along an axis extending through the piezoelectric crystal and an anatomic vessel. A force sensor disposed relative to the piezoelectric crystal may measure a force exerted (e.g., along skin of the vertebrate) on the anatomic vessel along the axis. The pulse echo received by the piezoelectric crystal and the force measured by the force sensor may, in combination, non-invasively and accurately determine a force response of the anatomic vessel. In turn, the force response may be probative of any one or more of a variety of different characteristics of the anatomic vessel including, for example, location of the anatomic vessel and pressure of the anatomic vessel.

Abstract: The presence of a return of spontaneous circulation (ROSC) in a patient is determined by evaluating physiological signals in the patient. In one embodiment, methods and devices device evaluate optical characteristics of light transmitted into a patient to ascertain physiological signals, such as pulsatile changes in general blood volume proximate a light detector module. Using these features, the methods and devices determine whether pulsatile blood flow is present in the patient and also whether the patient has ROSC based on whether the pulsatile blood flow is present. Some examples of the methods and devices indicate that the patient has ROSC if the patient's pulsatile blood flow is detected after defibrillation therapy has been delivered to the patient. Other example methods and devices either prompt a user to deliver additional defibrillation therapy to a patient or automatically deliver additional defibrillation therapy to a patient if the patient does not have ROSC.

Abstract: The present invention relates to an apparatus (26) and a method for determining a fractional flow reserve. For this purpose, a new personalized hyperemic boundary condition model is provided. The personalized hyperemic boundary condition model is used to condition a parametric model for a simulation of a blood flow in a coronary tree (34) of a human subject. As a basis for the personalized hyperemic boundary condition model, a predefined hyperemic boundary condition model is used, which represents empirical derived hyperemic boundary condition parameters. However, these empirical hyperemic boundary condition parameters are not specific for a human subject under examination. In order to achieve a specification of the respective predefined hyperemic boundary condition model, specific human subject features are derived from a volumetric image of the coronary tree of the human subject.

Abstract: Systems and methods for generating synthesized images are provided. An input medical image patch, a segmentation mask, a vector of appearance related parameters, and manipulable properties are received. A synthesized medical image patch including a synthesized nodule is generated based on the input medical image patch, the segmentation mask, the vector of appearance related parameters, and the manipulable properties using a trained object synthesis network. The synthesized nodule is synthesized according to the manipulable properties. The synthesized medical image patch is output.

Abstract: The present disclosure provides an electronic device and system that include an electrode interface that can be brought in contact with the body of a user, a memory, and a processor operably coupled to the electrode interface and the memory, in which the processor is set to obtain user information through user authentication, generate a user authentication signal on the basis of the user information, and transmit the user authentication signal or a signal including at least a portion of the user authentication signal through the body of a user being in contact with the electrode interface.

Abstract: A system and medical device for the electromagnetic tracking of a medical instrument transported through the medical device. The medical device has a central axis and a channel that receives and transports a medical instrument through the medical device. The channel extends to a distal portion of the medical device and connects with an opening in the medical device that is not aligned with the central axis. The medical device includes a tracking component that is a plurality of coordinated electromagnetic sensors for generating a virtual axis of travel for the medical instrument, with the virtual axis passing through the opening of the device and being aligned with tool insertion axis.

Abstract: A wireless cardiac sensor is provided. The sensor may be utilized by a patient, on themselves, in an at home or other non-clinical environment. A sensor housing contains ECG electrodes and an audio transducer to simultaneously capture heart sound and ECG data with a single device. The ECG electrodes may be positioned on opposite sides of, and preferably adjacent to, an audio transducer sensor, for placement against a user's chest. The wireless cardiac sensor may include a button on a surface opposite the ECG electrodes and audio sensor, facilitating one-handed operation by a patient. The sensor transmits acquired data to a personal electronic device, such as a smartphone, via a wireless communication link. The personal electronic device may in turn transmit data to a centralized server and/or health care provider devices, via a wide area network.

Abstract: The arterial health of an individual can be determined by: attaching a fingertip photopiethysmography device to a fingertip of the hand of the elevated arm of the individual; measuring the analog pulse contour of the individual using the fingertip photopiethysmography device; digitizing the analog pulse contour; analyzing the digitized pulse contour for stable waveforms; processing the stable waveforms of the digitized pulse contour using dynamic time warping; comparing the stable waveforms to a library of known disease state waveforms; and assigning a most probable disease state for the individual based on said comparison.

Abstract: Methods, compositions, and apparatuses are disclosed and described for assessing systemic immune response by monitoring changes of biophysical properties of mammalian immune cells or immune relevant bacterial cells in response to a gradient of chemoattractant in vitro.

Abstract: A biological information detection apparatus includes: a light source which projects a pattern of near-infrared light onto an object including a living body; an imaging system which includes first photodetector cells detecting light in a near-infrared wavelength range and second photodetector cells detecting light in a visible wavelength range, and generates a first image signal representing a first image, which is an image taken in the near-infrared wavelength range, of the object on which the pattern is projected, and a second image signal representing a second image of the object taken in the visible wavelength range; and a calculator which calculates biological information concerning the living body using at least one selected from the group consisting of the first and second image signals.

Abstract: A Nuclear magnetic Resonance (NMR)-based system for measuring physical properties of a fluid, the system comprising an NMR spectrometer, configured to allow subjection of the fluid to radio frequency (RF) signals within a generated magnetic field, measurement of RF signals remitted by the fluid, and production of an NMR image of the fluid, a conduit, with a at least one segment of non-circular cross-section for accommodation of the flow of the fluid, and a flow-inducing mechanism, configured to allow generation of the flow of the fluid within the conduit, wherein the computer processor is configured to allow analytic processing of data related to the physical properties of the fluid under conditions of laminar and mixed laminar-turbulent flow through the conduit of non-circular cross-section so as to allow measurement of shear stress and shear rate of the fluid.

Abstract: A wearable biometric monitoring device is configured to assess the biometric signal quality of one or more sensors associated with the monitoring device, determine how the user should adjust the device to improve the biometric fit, and instruct the user to wear the biometric monitoring device a certain way. Communicating instructions to a user may include instructing the user to execute a testing regimen while wearing the biometric monitoring device. The testing regimen facilitates an estimation of a signal quality that can be used to provide feedback to the user that he/she needs to adjust the device to improve the biometric fit and the biometric signal quality.

Abstract: A wearable biometric monitoring device includes a physiological sensor configured to detect and/or measure physiological information from a subject wearing the device, an accelerometer, and a processor. The processor is configured to analyze signals from the accelerometer to identify a 1G force vector on the biometric monitoring device, and determine whether an orientation of the 1G force vector is aligned with a desired vector for the 1G force. The device may also include a transmitter, and the processor is configured to communicate information, via the transmitter, to the subject that the device is being worn correctly if the orientation of the 1G force vector is aligned with the desired vector for the 1G force and to communicate information to the subject that the device is not being worn correctly if the orientation of the 1G force vector is not aligned with the desired vector for the 1G force.

Abstract: Example embodiments relate to systems and methods for heart rate detection with motion artifact reduction. One embodiment includes an electronic system for heart rate detection. The electronic system includes a random sampling sensor module. The random sampling sensor module includes a first sensor circuit configured to provide nonuniform random samples below a Nyquist rate of a photoplethysmographic signal. The random sample sensor module also includes a second sensor circuit configured to provided nonuniform random samples below a Nyquist rate of a motion signal. The motion signal and the photoplethysmographic signals are sampled with an equivalent pattern. The electronic system also includes a heart rate detection module. The heart rate detection module is configured to calculate a heart rave value based on frequencies corresponding to peak powers of calculated power spectral density value sets corresponding to the photoplethysmographic signals in a frequency range of interest.

Abstract: There is provided an apparatus for monitoring the ingestion of food and/or drink by a subject, the apparatus comprising a control unit that comprises a first obtaining module configured to obtain measurements of one or more physiological characteristics of the subject; a second obtaining module configured to obtain measurements of eddy currents generated in the body of the subject by an externally-applied magnetic field; a setting module configured to set a respective cut-off frequency for one or more filtering stages based on a respective frequency for each of said one or more physiological characteristics; a filtering module configured to filter the measurements of eddy currents using the one or more filtering stages to remove signal components due to the one or more physiological characteristics; and a processing module configured to process the filtered measurements to determine whether food and/or drink is present in the stomach of the subject.