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Background: Monitoring the vital signs of delirious patients in an intensive care unit (ICU) is challenging, as they might (un-)intentionally remove devices attached to their bodies. In mock-up scenarios, we systematically assessed whether a motion detector (MD) attached to the bed may help in identifying emergencies. Methods: We recruited 15 employees of the ICU and equipped an ICU bed with an MD (IRON Software GmbH, Grünwald, Germany). Participants were asked to replay 22 mock-up scenes of one-minute duration each: 12 scenes with movements and 10 without movements, of which 5 were emergency scenes ("lying dead-still, with no or very shallow breathing"). Blinded recordings were presented to an evaluation panel consisting of an experienced ICU nurse and a physician, who was asked to assess and rate the presence of motions. Results: Fifteen participants (nine women; 173 ± 7.0 cm; 78 ± 19 kg) joined the study. In total, 286 out of 330 scenes (86.7%) were rated correctly. Ratings were false negative (FN: "no movements detected, but recorded") in 7 out of 180 motion scenes (3.9%). Ratings were false positive (FP: "movements detected, but not recorded") in 37 out of 150 scenes (24.7%), more often in men than women (26 out of 60 vs. 11 out of 90, respectively; p < 0.001). Of note, in 16 of these 37 FP-rated scenes, a vibrating mobile phone was identified as a potential confounder. The emergency scenes were correctly rated in 64 of the 75 runs (85.3%); 10 of the 11 FP-rated scenes occurred in male subjects. Conclusions: The MD allowed for identifying motions of test subjects with high sensitivity (96%) and acceptable specificity (75%). Accuracy might increase further if activities are recorded continuously under real-world conditions. [ABSTRACT FROM AUTHOR]

Background: Monitoring the vital signs of delirious patients in an intensive care unit (ICU) is challenging, as they might (un-)intentionally remove devices attached to their bodies. In mock-up scenarios, we systematically assessed whether a motion detector (MD) attached to the bed may help in identifying emergencies. Methods: We recruited 15 employees of the ICU and equipped an ICU bed with an MD (IRON Software GmbH, Grünwald, Germany). Participants were asked to replay 22 mock-up scenes of one-minute duration each: 12 scenes with movements and 10 without movements, of which 5 were emergency scenes (“lying dead-still, with no or very shallow breathing”). Blinded recordings were presented to an evaluation panel consisting of an experienced ICU nurse and a physician, who was asked to assess and rate the presence of motions. Results: Fifteen participants (nine women; 173 ± 7.0 cm; 78 ± 19 kg) joined the study. In total, 286 out of 330 scenes (86.7%) were rated correctly. Ratings were false negative (FN: “no movements detected, but recorded”) in 7 out of 180 motion scenes (3.9%). Ratings were false positive (FP: “movements detected, but not recorded”) in 37 out of 150 scenes (24.7%), more often in men than women (26 out of 60 vs. 11 out of 90, respectively; p < 0.001). Of note, in 16 of these 37 FP-rated scenes, a vibrating mobile phone was identified as a potential confounder. The emergency scenes were correctly rated in 64 of the 75 runs (85.3%); 10 of the 11 FP-rated scenes occurred in male subjects. Conclusions: The MD allowed for identifying motions of test subjects with high sensitivity (96%) and acceptable specificity (75%). Accuracy might increase further if activities are recorded continuously under real-world conditions.

The optic lobe of the fly is one of the prominent model systems for the neural mechanism of the motion detection. How a fly who lives under various visual situations of the nature processes the information from at most a few thousands of ommatidia in their neural circuit for the detection of moving objects is not exactly clear though many computational models of the fly optic lobe as a moving objects detector were suggested. Here we attempted to elucidate the mechanisms of ON-edge motion detection by a simulation approach based on the TEM connectome of Drosophila. Our simulation model of the optic lobe with the NEURON simulator that covers the full scale of ommatidia, reproduced the characteristics of the receptor neurons, lamina monopolar neurons, and T4 cells in the lobula. The contribution of each neuron can be estimated by changing synaptic connection strengths in the simulation and measuring the response to the motion stimulus. Those show the paradelle pathway provide motion detection in the fly optic lobe has more robustness and is more sophisticated than a simple combination of HR and BL systems. [ABSTRACT FROM AUTHOR]

Background. Lighting control systems in urban environments aim to improve the energy efficiency of lighting systems. The introduction of such technologies will significantly reduce energy costs in the urban environment. The aim of the study is to find and develop an optimal solution for controlling the illumination level of urban lighting devices, depending on the traffic activity of vehicles and the population. Materials and methods. To study intelligent urban lighting control systems, methods of analysis and synthesis of similar systems, and methods of modeling and visualization of the developed solution were used. Results and conclusions. An intelligent urban lighting system capable of adjusting the light intensity depending on traffic activity in the monitoring area has been investigated. The proposed system is considered as a tool for solving energy conservation problems and the basis for designing a smart city.

Employing inexact arithmetic circuits in error-resilient applications results in reduction of hardware-level metrics such as power consumption, delay and occupied area. These criteria are very important in portable applications because they are battery limited. Full Adder cell is as a building block of many arithmetic circuits. Therefore, it can influence the performance of the entire digital system. This paper presents a novel low-power and high-speed design of one-bit inexact full adder cell based on 32-nm (CNFET) technology for error resilient applications. This design technique can be utilized in various applications particularly in image processing. The presented design employs capacitive threshold logic (CTL) approach which significantly reduces the number of transistors. The peak signal-to-noise ratio (PSNR) is considered to evaluate accuracy of circuits at application level. Then extensive simulations regarding various power supplies, temperatures and loads at transistor level are performed to measure power consumption and propagation delay criteria. Moreover, some new metrics are introduced to trade-off between application and hardware level parameters. Comprehensive simulations demonstrate the supremacy of the proposed cell than others. [ABSTRACT FROM AUTHOR]

The radio signals range of selected wireless components of security systems is defined by the area within which components can communicate properly. In practice, the range of communication between components is often insufficiently taken into account, which results in the system malfunction. There are cases where the radio signal range of wireless components was inadequate due to use in an environment constructed from non-transmitting materials.The installation of wireless systems requires the implementation of a testing methodology of radio-communication range and its continuous improvement. Currently, the procedures within EN 50 131-5-3 and EN 300 220-1 standards can be used to test the wireless components, but they do not target the range between wireless components. Dependability and functionality are the main attributes of electrical security systems and need to be verified by testing the range of wireless components.

This paper deals with the design and implementation of Raspberry Pi Secure Home Automation for mobile applications using mobile technology, which ensure that we are safe in our home, and related monitoring activities. Our new integration of the camera and motion detector is the key to our proposed Home Security solution. Raspberry Pi operates and controls remote sensing, live video sharing and recording, and handles tasks for potential replication on home hardware, such as turning on/off a TV or a microwave. Initially, when the activity is detected and Raspberry Pi alerts householders for possible interference, the cameras will automatically start recording. Raspberry Pi has two primary interaction parts: web applications running on the portable device browser, and server scripts running on the Raspberry Pi hardware element in the cloud. Due to its friendliness and ease of use, we have decided to include domestic security and home safety in a single program. For example, when an attacker enters a room, the PRI sensors detect the activity and trigger the monitor, and the camera captures photos of an individual interacting with a live video feed. Additional backup and email services are also provided for the customer, which provides better recovery facility for the user. [ABSTRACT FROM AUTHOR]

This paper presents a water intake monitoring system for animal agriculture that tracks individual animal watering behavior, water quality, and water consumption. The system is deployed in an outdoor environment to reach remote areas. The proposed system integrates motion detectors, cameras, water level sensors, flow meters, Radio-Frequency Identification (RFID) systems, and water temperature sensors. The data collection and control are performed using Arduino microcontrollers with custom-designed circuit boards. The data associated with each drinking event are water consumption, water temperature, drinking duration, animal identification, and pictures. The data and pictures are automatically stored on Secure Digital (SD) cards. The prototypes are deployed in a remote grazing site located in Tucumcari, New Mexico, USA. The system can be used to perform water consumption and watering behavior studies of both domestic animals and wild animals. The current system automatically records the drinking behavior of 29 cows in a two-week duration in the remote ranch.

ABSTRACT: Wearable and antibacterial porous devices are promising new multifunctional materials with a wide range of applications in wound dressing and human motion monitoring systems. The deposition of carbon nanotubes and polypyrrole coating on conventional elastomers (polyurethane) is a single‐step procedure that results in a low‐cost, highly conductive, and flexible piezoresistive material with pressure sensitivity of 0.09 kPa−1, Gauge Factor of −10.3, high stability in response to different mechanical efforts and reversible netlike microcracks formation under moderate stretching deformation. The resulting porous material provides direct detection of simple movements from human joints (knee, finger, and elbow) and intrinsic antibacterial activity against Staphylococcus aureus, Klebsiella pneumoniae, and Escherichia coli. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 1063–1072 [ABSTRACT FROM AUTHOR]

The radio signals range of selected wireless components of security systems is defined by the area within which components can communicate properly. In practice, the range of communication between components is often insufficiently taken into account, which results in the system malfunction. There are cases where the radio signal range of wireless components was inadequate due to use in an environment constructed from non-transmitting materials. The installation of wireless systems requires the implementation of a testing methodology of radio-communication range and its continuous improvement. Currently, the procedures within EN 50 131-5-3 and EN 300 220-1 standards can be used to test the wireless components, but they do not target the range between wireless components. Dependability and functionality are the main attributes of electrical security systems and need to be verified by testing the range of wireless components. [ABSTRACT FROM AUTHOR]

In this paper, three novel low-power and high-speed 1-bit inexact Full Adder cell designs are presented based on current mode logic in 32 nm carbon nanotube field effect transistor technology for the first time. The circuit-level figures of merits, i.e. power, delay and power-delay product as well as application-level metric such as error distance, are considered to assess the efficiency of the proposed cells over their counterparts. The effect of voltage scaling and temperature variation on the proposed cells is studied using HSPICE tool. Moreover, using MATLAB tool, the peak signal to noise ratio of the proposed cells is evaluated in an image-processing application referred to as motion detector. Simulation results confirm the efficiency of the proposed cells. [ABSTRACT FROM AUTHOR]

This study aimed to examine motion detector with pir sensor,a commonly used sensor which detects objects or living creatures by the heat they emit. This kind of sensors are important when we aim to save energy and in fact, they are good to use almost in both everyday life and high technology. This sensor is bought together with a circuit we've designed.

This paper presents a novel inexact full adder based on carbon nanotube field-effect transistors (CNTFET) for approximate computations, which has soared in popularity especially for image processing applications. The proposed design generates the output carry without error. Therefore, the propagation of incorrect value to higher bit positions is avoided. It has the least relative error distance (Relative ED) compared to other approximate full adders reported in the literature. Practical simulations by using MATLAB demonstrate higher peak signal to noise ratio (PSNR) and image quality for motion detector image processing application. HSPICE simulations also confirm the efficiency of the proposed design. Moreover, area occupation is investigated by using electric tool. Power consumption, delay, area and ED are important evaluating factors in this subject. Comparisons are made by a comprehensive parameter (PDAEDP), based on which the new design has 23.8%, 41.5%, 70.5%, 78% and 83.6% higher performance than TGA1, TGA2, AXA1, AXA2 and AXA3, respectively. [ABSTRACT FROM AUTHOR]

This paper presents a region-based method for background subtraction. It relies on color histograms, texture information, and successive division of candidate rectangular image regions to model the background and detect motion. Our proposed algorithm uses this principle and combines it with Gaussian Mixture background modeling to produce a new method which outperforms the classic Gaussian Mixture background subtraction method. Our method has the advantages of filtering noise during image differentiation and providing a selectable level of detail for the contour of the moving shapes. The algorithm is tested on various video sequences and is shown to outperform state-of-the-art background subtraction methods.

During the production of iodine-131 from neutron irradiated tellurium dioxide by the dry distillation, a considerable amount of 131 I vapor is dispersed to the indoor air. People who routinely work at the production area may result in a significant risk of exposure to chronic intake by inhaled 131 I. This study aims to estimate the inhalation dose for individuals manipulating the 131 I at a radioisotope production. By using an application installed on smartphones, we collected the time-microenvironment data spent by a radiation group during work days in 2015. Simultaneously, we used a portable air sampler combined with radioiodine cartridges for grabbing the indoor air samples and then the daily averaged 131 I concentration was calculated. Finally, the time-microenvironment data jointed with the concentration to estimate the inhalation dose for the workers. The result showed that most of the workers had the annual internal dose in 1÷6 mSv. We concluded that using smartphone as a motion detector is a possible and reliable way instead of the questionnaires, diary or GPS-based method. It is, however, only suitable for monitoring on fixed indoor environments and limited the targeted people. [ABSTRACT FROM AUTHOR]

Automated behavioural observations are routinely used in many fields of biology, including ethology, behavioural ecology and physiology. When preferences for certain resources are investigated, the focus is often on simple response variables, such as duration and frequency of visits to choice chambers. Here we present an automated motion detector system that use passive infrared sensors to eliminate many drawbacks of currently existing methods. Signals from the sensors are processed by a custom-built interface, and after unnecessary data is filtered by a computer software, the total time and frequency of the subject's visits to each of the choice chambers are calculated. We validate the detector system by monitoring (using the system) and in the same time video recording mating preferences of zebra finches in a four-way choice apparatus. Manual scoring of the video recordings showed very high consistency with data from the detector system both for time and for frequency of visits. Furthermore, the validation revealed that if we used micro-switches or light barriers, the most commonly applied automatic detection techniques, this would have resulted in approximately 22% less information compared to our lossless system. The system provides a low-cost alternative for monitoring animal movements, and we discuss its further applicability. [ABSTRACT FROM AUTHOR]

Lightning is known as a discharge of atmospheric electricity that is triggered by a build-up of differing charges within a cloud. The result is a sudden release of energy that causes a distinctive bright flare, followed by a thunderclap. Lightning is a transient, high-current discharge whose path length is measured in kilometers. Each lightning bolt can contain from 3000 to 200000 amperes of electricity. A reliable protection against lightning has become very essential for buildings. Therefore buildings are constructed to include protective elements known as lightning conductor or lightning rod. Lightning conductor is a metal rod or metallic object mounted on top of a building, electrically bonded using a wire or electrical conductor to interface with ground through an electrode. Magnetic induction and magnetic field strength formed as a result of lightning cause motion detector errors and at the same time affect the wires of these motion detectors. This study presents an investigation and the results of electromagnetic coupling effects of the magnetic fields created by flowing high currents in through lightning conductors on indoor motion detectors and their cables using finite element method (FEM). [ABSTRACT FROM AUTHOR]

Abstract: This paper reports the screen printing of free-standing cantilever beams on to fabric, for use as motion detectors. Such low cost motion detectors could be used in clothing as activity monitors to indicate if the wearer is unconscious in safety critical applications, e.g. a fireman in a building. We have fabricated capacitive free-standing cantilevers by screen printing sacrificial and structural materials onto a fabric substrate. In this paper, these devices are used as motion detectors which are mounted and tested on a human forearm alongside a commercial accelerometer, for comparison. The results show the feasibility of using a fabric based cantilever to indicate that the wearer is moving. [Copyright &y& Elsevier]

This study aimed to examine motion detector with pir sensor,a commonly used sensor which detects objects or living creatures by the heat they emit. This kind of sensors are important when we aim to save energy and in fact, they are good to use almost in both everyday life and high technology. This sensor is bought together with a circuit we’ve designed. [ABSTRACT FROM AUTHOR]

Abstract: A series of experiments investigated the extent to which the spatial orientation of a signal line affects discrimination of its trajectory from the random trajectories of background noise lines. The orientation of the signal line was either parallel (iso-) or orthogonal (ortho-) to its motion direction and it was identical in all respects to the noise (orientation, length and speed) except for its motion direction, rendering the signal line indistinguishable from the noise on a frame-to-frame basis. We found that discrimination of ortho-trajectories was generally better than iso-trajectories. Discrimination of ortho-trajectories was largely immune to the effects of spatial jitter in the trajectory, and to variations in step size and line-length. Discrimination of iso-trajectories was reliable provided that step-size was not too short and did not exceed line length, and that the trajectory was straight. The new result that trajectory discrimination in moving line elements is modulated by line orientation suggests that ortho- and iso-trajectory discrimination rely upon two distinct mechanisms: iso-motion discrimination involves a ‘motion-streak’ process that combines motion information with information about orientation parallel to the motion trajectory, while ortho-motion discrimination involves extended trajectory facilitation in a network of receptive fields with orthogonal orientation tuning. [Copyright &y& Elsevier]

Abstract: This study assessed whether two persons with profound multiple disabilities would be able to control environmental stimulation using hand swing and a standard mouse with a newly developed mouse driver (i.e. a new mouse driver replaces standard mouse driver, and turns a mouse into a precise two-dimensional motion detector). The study was performed according to an ABAB design and included a 2-month post-intervention check. Data showed that both participants significantly increased their target response (hand swing) to activate the control system to produce environmental stimulation during the B (intervention) phases. This performance was maintained at the post-intervention check. Practical and developmental implications of the findings were discussed. [Copyright &y& Elsevier]

This paper proposes a CMOS motion detector which consumes extremely low power. CMOS Image sensor pixels in this motion detector senses image and image data are converted into just one-bit by using clocked comparators. Because using one-bit data makes additional processing units simple, total power consumption of this CMOS motion detector can be reduced. That is, internal memory which is composed of the clocked gating schemes based on the flip -flop and XOR function which compares a current image with a previous one in order to detect a difference are main features for the simple structure. However one-bit data process has a critical problem that it is hard to detect a motion when image inclines to white or block. For solving this problem, Reference Voltage Controller which makes about the same proportion of white and block is implemented. We have made a test module of the proposed CMOS motion detector and tested it by using FPGA. According to the measurement result, total power consumption is about 32 μW at 3.3 V. Therefore, this motion detector can be useful for portable battery-operated devices. [ABSTRACT FROM AUTHOR]

Abstract: For many animal species that are difficult to access, the behaviour of free-ranging individuals cannot be assessed by direct observation. In order to remedy this, we developed a new technique using a motion detector (acceleration data-logger) for monitoring the activity and behaviour of free-ranging vertebrates and tested its efficiency on a domestic cat, Felis catus. A total of 3615min of surging acceleration was measured along the longitudinal body axis of an adult male cat. The cat''s behaviour was also filmed for 113min, these video data being used to correlate the logger''s signals with the cat''s behaviour. Acceleration data-loggers attached on the cat''s collar recorded acceleration signals which were influenced by both the gravitational acceleration resulting from the body posture and the dynamic acceleration resulting from the dynamic behaviour of the cat. By applying spectral analysis based on a fast Fourier Transform to acceleration signals, body postures and some of the dynamic behaviours of the cat such as drinking, eating, and several paces of travelling were efficiently determined. The present study shows that acceleration data-loggers represent a useful and reliable system for accurately recording the activities and detail behaviours of the terrestrial animals. [Copyright &y& Elsevier]

Abstract: We have developed a visually based autopilot which is able to make an air vehicle automatically take off, cruise and land, while reacting appropriately to wind disturbances (head wind and tail wind). This autopilot consists of a visual control system that adjusts the thrust so as to keep the downward optic flow (OF) at a constant value. This autopilot is therefore based on an optic flow regulation loop. It makes use of a sensor, which is known as an elementary motion detector (EMD). The functional structure of this EMD was inspired by that of the housefly, which was previously investigated at our Laboratory by performing electrophysiological recordings while applying optical microstimuli to single photoreceptor cells of the insect''s compound eye. We built a proof-of-concept, tethered rotorcraft that circles indoors over an environment composed of contrasting features randomly arranged on the floor. The autopilot, which we have called OCTAVE (Optic flow based Control sysTem for Aerial VEhicles), enables this miniature (100g) rotorcraft to carry out complex tasks such as ground avoidance and terrain following, to control risky maneuvers such as automatic take off and automatic landing, and to respond appropriately to wind disturbances. A single visuomotor control loop suffices to perform all these reputedly demanding tasks. As the electronic processing system required is extremely light-weight (only a few grams), it can be mounted on-board micro-air vehicles (MAVs) as well as larger unmanned air vehicles (UAVs) or even submarines and autonomous underwater vehicles (AUVs). But the OCTAVE autopilot could also provide guidance and/or warning signals to prevent the pilots of manned aircraft from colliding with shallow terrain, for example. [Copyright &y& Elsevier]

Functional MRI studies are very sensitive to motion; head movements of as little as 1-mm translations or 1° rotations may cause spurious signals. An algorithm was developed that uses k-space MRI data to monitor subject motion during functional MRI time series. A k-space weighted average of squared difference between the initial scan and subsequent scans is calculated, which summarizes subject motion in a single quality parameter; however, the quality parameter cannot be used for motion correction. The evolution of this quality parameter throughout a time series indicates whether head motion is within a predetermined limit. Fifty functional MRI studies were used to calibrate the sensitivity of the algorithm, using the six rigid-body registration parameters (three translations and three rotations) from the statistical parametric mapping (SPM99) package as a reference. The average correlation coefficient between the new quality parameter and the reference value from SPM was 0.84. The simple algorithm correctly classified acceptable or excessive motion with 90% accuracy, with the remaining 10% being borderline cases. This method makes it possible to evaluate brain motion within seconds after a scan and to decide whether a study needs to be repeated. [Copyright &y& Elsevier]

ABSTRACT The visual response properties are described of a group of retinal slip neurons in the wallaby pretectum, referred to as slow cells. Their responses to motion are direction-selective: tempero-nasal and naso-temporal motion over the contralateral eye increase and decrease, respectively, the firing rate relative to the spontaneous level. Slow cells are maximally sensitive to image velocities from 0.08 to 10°/s. The present study focuses on slow cells that are maximally sensitive to image velocities below 1°/s. An interesting characteristic of 82% of slow cells is that once motion stops, the firing rate exhibits a same-sign after-response. This is characterized by a slow exponential return from the firing rate during motion to the spontaneous rate. The time constants of the after-responses are independent of the temporal frequency, velocity, duration and direction of the motion stimulus. It is proposed that the neurons may assist the stabilization of eye position during fixation. [ABSTRACT FROM AUTHOR]

Sensing visual motion gives a creature valuable information about its interactions with the environment. Flies in particular use visual motion information to navigate through turbulent air, avoid obstacles, and land safely. Mobile robots are ideal candidates for using this sensory modality to enhance their performance, but so far have been limited by the computational expense of processing video. Also, the complex structure of natural visual scenes poses an algorithmic challenge for extracting useful information in a robust manner. We address both issues by creating a small, low-power visual sensor with integrated analog parallel processing to extract motion in real-time. Because our architecture is based on biological motion detectors, we gain the advantages of this highly evolved system: A design that robustly and continuously extracts relevant information from its visual environment. We show that this sensor is suitable for use in the real world, and demonstrate its ability to compensate for an imperfect motor system in the control of an autonomous robot. The sensor attenuates open-loop rotation by a factor of 31 with less than 1 mW power dissipation. [ABSTRACT FROM AUTHOR]

This paper presents a water intake monitoring system for animal agriculture that tracks individual animal watering behavior, water quality, and water consumption. The system is deployed in an outdoor environment to reach remote areas. The proposed system integrates motion detectors, cameras, water level sensors, flow meters, Radio-Frequency Identification (RFID) systems, and water temperature sensors. The data collection and control are performed using Arduino microcontrollers with custom-designed circuit boards. The data associated with each drinking event are water consumption, water temperature, drinking duration, animal identification, and pictures. The data and pictures are automatically stored on Secure Digital (SD) cards. The prototypes are deployed in a remote grazing site located in Tucumcari, New Mexico, USA. The system can be used to perform water consumption and watering behavior studies of both domestic animals and wild animals. The current system automatically records the drinking behavior of 29 cows in a two-week duration in the remote ranch. [ABSTRACT FROM AUTHOR]

In this paper, we present two novel approximate Full Adder cells with capacitive threshold logic (CTL) using carbon nanotube field-effect transistor (CNFET) technology. To investigate the efficiency of the proposed cells, extensive simulations are carried out at both application and transistor levels. At the application level, by using the MATLAB tool, the proposed cells are applied to the motion detector algorithm as one of the practical image processing applications. Peak signal-to-noise ratio (PSNR) is considered as a legitimate application-level evaluating factor. In addition, by using the HSPICE tool, the hardware level parameters such as average power consumption, delay, and power-delay product (PDP) are estimated. Then, a compromise between the application and hardware-level metrics is considered. Noise analysis is also accomplished by taking noise immunity curve (NIC) and average noise threshold energy (ANTE) into account. Furthermore, Monte Carlo transient analysis is exploited to study the robustness of the introduced cells against diameter deviations of the carbon nanotubes (CNTs). Simulation results indicate the supremacy of the proposed cells compared to others. [ABSTRACT FROM AUTHOR]

A pulse Doppler radar with one-dimensional direction sensitivity is described. The system uses quadrature mixing to retain the direction information in an echo signal, and performs signal sampling over a predetermined time slot to ignore reflected signals from objects outside the range of interest. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 17: 227–229, 1998. [ABSTRACT FROM AUTHOR]

Physical activity is a critical behavioral variable in many research studies and is, therefore, important to quantify. However, existing methods for measuring physical activity have limitations which include high expense, specialized caging or equipment, and high computational overhead. To address these limitations, we present an open-source, cost-effective, device for measuring rodent activity. Our device is battery powered and designed to be placed in vivarium home cages to enable high-throughput, long-term operation with minimal investigator intervention. The primary aim of this study was to assess the feasibility of using passive infrared (PIR) sensors and microcontroller-based dataloggers in a rodent home cages to collect physical activity records. To this end, we developed an open-source PIR based data-logging device called the rodent activity detector (RAD). We publish the design files and code so others can readily build the RAD in their own labs. To demonstrate its utility, we used the RAD to collect physical activity data from 40 individually housed mice for up to 10 weeks. This dataset demonstrates the ability of the RAD to (1) operate in a high-throughput installation, (2) detect high-fat diet (HFD)-induced changes in physical activity, and (3) quantify circadian rhythms in individual animals. We further validated the data output of the RAD with simultaneous video tracking of mice in multiple caging configurations, to determine the features of physical activity that it detects. The RAD is easy to build, economical, and fits in vivarium caging. The scalability of such devices will enable high-throughput studies of physical activity in research studies., (Copyright © 2019 Matikainen-Ankney et al.)