Pattern and component responses of primate MT neurons recorded with multi-contact electrodes, stimulated with 1D and 2D noise patterns.

Direction selective neurons in primary visual cortex (area V1) are affected by the aperture problem, i.e., they are only sensitive to motion orthogonal to their preferred orientation. A solution to this problem first emerges in the middle temporal (MT) area, where a subset of neurons (called pattern cells) combine motion information across multiple orientations and directions, becoming sensitive to pattern motion direction. These cells are expected to play a prominent role in subsequent neural processing, but they are intermixed with cells that behave like V1 cells (component cells), and others that do not clearly fall in either group. The picture is further complicated by the finding that cells that behave like pattern cells with one type of pattern, might behave like component cells for another. We recorded from macaque MT neurons using multi-contact electrodes while presenting both type I and unikinetic plaids, in which the components were 1D noise patterns. We found that the indices that have been used in the past to classify neurons as pattern or component cells work poorly when the properties of the stimulus are not optimized for the cell being recorded, as is always the case with multi-contact arrays. We thus propose alternative measures, which considerably ameliorate the problem, and allow us to gain insights in the signals carried by individual MT neurons. We conclude that arranging cells along a component-to-pattern continuum is an oversimplification, and that the signals carried by individual cells only make sense when embodied in larger populations.

In-Body Electromagnetic Sensor Combined with AI-Enhanced Electrocardiography for Pacemaker Working Status Telemonitoring

This paper describes the design and implementation of an in-body electromagnetic sensor for patients with implanted pacemakers. The sensor can either be mounted on myocardial tissue and monitor the electrocardiography (ECG) with contact electrodes or implanted under the skin and monitor the ECG with coaxial leads. A 16-bit high-resolution analog front-end (AFE) and an energy-efficient 32-bit CPU are used for instantaneous ECG recording. Wireless data transmission between the sensor and clinician’s computer is achieved by an embedded low-power Bluetooth transmitter. In order to automatically recognize the working status of the pacemaker and alarm the episodes of arrhythmias caused by pacemaker malfunctions, pacing mode classification and fault diagnosis on the recorded ECG were achieved based on an AI algorithm, i.e., a resource allocation network (RAN). A prototype of the sensor was implemented on a human torso, and the in vitro test results prove that the sensor can work properly for the 1-4-meter transmission range.

Bioimpedance plethysmography with capacitive electrodes and sole force sensors: comparative trial

Foot impedance plethysmography was implemented using two types of electrodes (dry and capacitive) and sole force sensors. The latter are commonly used for assessing diabetic foot ulcers (DFU). For impedance plethysmography, a tetrapolar configuration has been used with three different plantar setups: four skin contact electrodes, four capacitive contact electrodes and two Force Sensing Resistors (FSRs). In this work, FSRs have been considered as possible capacitive electrodes because the top substrate contains interdigitating conductive electrodes and a semiconductive polymer. All the measurements have been performed using a 1 mA/10 kHz excitation current and have been tried under the feet of a standing person to detect impedance plethysmography signals. Contact electrodes allow a good cardiac pulse signal while capacitive contact through the socks features mains interferences. Force sensing resistors with their force-dependent resistance in parallel to the capacitive coupling, were not able to detect cardiac pulse. But promising results can be anticipated from these findings provided higher frequencies are used and larger sensor areas to help detect altered skin states in diabetic foot.

Automated Low Investment Cost Evaporometers (ALICEs)

Evaporation is an important part of the hydrological cycle. This paper discusses the materials and methods we used to develop an evaporometer, which measures evaporation from the water surface, like a drop in water level. The main problem is that there are relatively small differences in the levels measured directly in the field. During the research, we tested conductive filament and stainless steel as measuring electrode materials. We used 3D printing in combination with low-cost open-source electronics and a hand-etched circuit board to make a device which measures the free water surface level. A 3D printed jig is used when assembling the device, and this ensures that the contact electrodes are set precisely. Another 3D printed jig is used to create the etched circuit board, which holds all the electronic devices. The device uses the low-cost open-source Arduino Uno electronics microcontroller board. Our results show that high-precision measurements can be gathered with the use of open-source electronics in 3D printed housing. The device is also durable and easy to maintain.

Forensic characteristics of damages to different types of fabrics (materials of clothing), which are formed due to the effect of electric shock devices

Annotation. The article describes the results of a study of experimentally caused damage to various types of non-biological material (simulators of clothing fabrics) under the action of different models of electroshock devices. Particularly, the morphological features of the damages and the elemental chemical composition in the areas of damages are established. In the study, 120 experimental objects were investigated – damage to four types of clothing fabrics (imitators of clothing fabrics – cotton knitwear, linen, synthetic fabrics) caused by the action of three models of electric shock devices. Applied research methods: visual examination (including via optical devices), morphometric, photographic, X-ray fluorescent spectral analysis, statistical. The research results are processed by standard methods of variation statistics. The purpose of the study is to establish the forensic diagnostic criteria for assessing damage to various fabrics (materials) of clothing, causing by the action of electric shock devices. In the course of the experiment, certain morphological features of damage were established, which are formed as a result of the action of electroshock devices on various types of materials (imitators of clothing fabrics). The results of the study indicate that the design features of electro-shock devices are reflected in the morphological pattern of damages on the tissues of clothing, namely, in the nature of the mutual arrangement of injuries, the distance between them, which can be used in forensic practice, as a sign indicating the action of an electroshock device specific model. When carrying out X-ray fluorescence spectral analysis from areas of material damage (simulators of clothing fabrics), metal deposits were found, which, in terms of their elemental composition, corresponded to the chemical composition of the contact electrodes of electroshock devices that caused damage. This regularity can be used as an objective sign of establishing the fact of the action of an electroshock device with a certain elemental composition of the metal of the contact electrodes.

Optimal Closed-loop Deep Brain Stimulation with Multi-Contact Electrodes

Deep brain stimulation (DBS) is a well-established treatment option for a variety of neurological disorders, including Parkinson’s disease (PD) and essential tremor (ET). It is widely believed that the efficacy, efficiency and side-effects of the treatment can be improved by stimulating ‘closed-loop’, according to the symptoms of a patient. Multi-contact electrodes powered by independent current sources are a recent development in DBS technology which allow for greater precision when targeting one or more pathological regions but, in order to realise the potential of such systems, algorithms must be developed to deal with their increased complexity. This motivates the need to understand how applying DBS to multiple regions (or neural populations) can affect the efficacy and efficiency of the treatment. On the basis of a theoretical model, our paper aims to address the question of how to best apply DBS to multiple neural populations to maximally desynchronise brain activity. Using a coupled oscillator model, we derive analytical expressions which predict how the symptom severity should change as a result of applying stimulation. On the basis of these expressions we derive an algorithm describing when the stimulation should be delivered to individual contacts. Remarkably, these expressions also allow us to determine the conditions for when stimulation using information from individual contacts is likely to be advantageous. Using numerical simulation, we demonstrate that our methods have the potential to be both more effective and efficient than existing methods found in the literature.