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Biomedical Engineering Letters May 2022Conventional spike sorting and motor intention decoding algorithms are mostly implemented on an external computing device, such as a personal computer. The innovation of...
Conventional spike sorting and motor intention decoding algorithms are mostly implemented on an external computing device, such as a personal computer. The innovation of high-resolution and high-density electrodes to record the brain's activity at the single neuron level may eliminate the need for spike sorting altogether while potentially enabling in vivo neural decoding. This article explores the feasibility and efficient realization of in vivo decoding, with and without spike sorting. The efficiency of neural network-based models for reliable motor decoding is presented and the performance of candidate neural decoding schemes on sorted single-unit activity and unsorted multi-unit activity are evaluated. A programmable processor with a custom instruction set architecture, for the first time to the best of our knowledge, is designed and implemented for executing neural network operations in a standard 180-nm CMOS process. The processor's layout is estimated to occupy 49 mm of silicon area and to dissipate 12 mW of power from a 1.8 V supply, which is within the tissue-safe operation of the brain.
PubMed: 35529345
DOI: 10.1007/s13534-022-00217-z -
Frontiers in Neuroscience 2022Interictal high-frequency oscillations (HFO) detected in electroencephalography recordings have been proposed as biomarkers of epileptogenesis, seizure propensity,... (Review)
Review
Interictal high-frequency oscillations (HFO) detected in electroencephalography recordings have been proposed as biomarkers of epileptogenesis, seizure propensity, disease severity, and treatment response. Automatic HFO detectors typically analyze the data offline using complex time-consuming algorithms, which limits their clinical application. Neuromorphic circuits offer the possibility of building compact and low-power processing systems that can analyze data on-line and in real time. In this review, we describe a fully automated detection pipeline for HFO that uses, for the first time, spiking neural networks and neuromorphic technology. We demonstrated that our HFO detection pipeline can be applied to recordings from different modalities (intracranial electroencephalography, electrocorticography, and scalp electroencephalography) and validated its operation in a custom-designed neuromorphic processor. Our HFO detection approach resulted in high accuracy and specificity in the prediction of seizure outcome in patients implanted with intracranial electroencephalography and electrocorticography, and in the prediction of epilepsy severity in patients recorded with scalp electroencephalography. Our research provides a further step toward the real-time detection of HFO using compact and low-power neuromorphic devices. The real-time detection of HFO in the operation room may improve the seizure outcome of epilepsy surgery, while the use of our neuromorphic processor for non-invasive therapy monitoring might allow for more effective medication strategies to achieve seizure control. Therefore, this work has the potential to improve the quality of life in patients with epilepsy by improving epilepsy diagnostics and treatment.
PubMed: 35720714
DOI: 10.3389/fnins.2022.861480 -
Nature Communications Dec 2022Tensor analytics lays the mathematical basis for the prosperous promotion of multiway signal processing. To increase computing throughput, mainstream processors...
Tensor analytics lays the mathematical basis for the prosperous promotion of multiway signal processing. To increase computing throughput, mainstream processors transform tensor convolutions into matrix multiplications to enhance the parallelism of computing. However, such order-reducing transformation produces data duplicates and consumes additional memory. Here, we propose an integrated photonic tensor flow processor (PTFP) without digitally duplicating the input data. It outputs the convolved tensor as the input tensor 'flows' through the processor. The hybrid manipulation of optical wavelengths, space dimensions, and time delay steps, enables the direct representation and processing of high-order tensors in the optical domain. In the proof-of-concept experiment, an integrated processor manipulating wavelengths and delay steps is implemented for demonstrating the key functionalities of PTFP. The multi-channel images and videos are processed at the modulation rate of 20 Gbaud. A convolutional neural network for video action recognition is demonstrated on the processor, which achieves an accuracy of 97.9%.
PubMed: 36577748
DOI: 10.1038/s41467-022-35723-2 -
Science and Technology of Advanced... Jun 2020Recent advancements in molecular robotics have been greatly contributed by the progress in various fields of science and technology, particularly in supramolecular... (Review)
Review
Recent advancements in molecular robotics have been greatly contributed by the progress in various fields of science and technology, particularly in supramolecular chemistry, bio- and nanotechnology, and informatics. Yet one of the biggest challenges in molecular robotics has been controlling a large number of robots at a time and employing the robots for any specific task as flocks in order to harness emergent functions. Swarming of molecular robots has emerged as a new paradigm with potentials to overcome this hurdle in molecular robotics. In this review article, we comprehensively discuss the latest developments in swarm molecular robotics, particularly emphasizing the effective utilization of bio- and nanotechnology in swarming of molecular robots. Importance of tuning the mutual interaction among the molecular robots in regulation of their swarming is introduced. Successful utilization of DNA, photoresponsive molecules, and natural molecular machines in swarming of molecular robots to provide them with processing, sensing, and actuating ability is highlighted. The potentials of molecular swarm robots for practical applications by means of their ability to participate in logical operations and molecular computations are also discussed. Prospects of the molecular swarm robots in utilizing the emergent functions through swarming are also emphasized together with their future perspectives.
PubMed: 32939158
DOI: 10.1080/14686996.2020.1761761 -
The Journal of International Advanced... Nov 2023RONDO 2 is a lightweight, compact, wirelessly charged, and fully integrated single-unit speech processor. Single-unit processors provide an effective and convenient...
BACKGROUND
RONDO 2 is a lightweight, compact, wirelessly charged, and fully integrated single-unit speech processor. Single-unit processors provide an effective and convenient alternative to behind-the-ear processors for adults. Therefore, the aim of this study was to investigate if RONDO 2 is suitable for and did not compromise the hearing performance of young children in everyday life.
METHODS
Thirteen children aged -lt;4 years were fitted with the RONDO 2 speech processor at the first activation of the cochlear implant. They were evaluated with the LittlEARS® Auditory Questionnaire, LittlEARS® Early Speech Production Questionnaire, and the Speech, Spatial, and Qualities of Hearing Scale 12 pre-implantation. In addition to these measures, they were evaluated with the Audio Processor Satisfaction Questionnaire post-implantation. Duration of daily use and troubleshooting data were acquired. Evaluation occurred at 4 time points: before implantation and 1, 3, and 12 months post-initial activation.
RESULTS
Ten out of 13 children continued using RONDO 2 after the study. Twelve months after implantation, they used it on average 11.6 hours per day and had an average Audio Processor Satisfaction Questionnaire score of 9.1 out of 10. Average hearing performance scores continuously improved throughout the follow-up period across measures. Twelve months after implantation, the mean scores were 30.1 out of 35 for the LittlEARS® Auditory Questionnaire, 19.9 out of 27 for the LittlEARS® Early Speech Production Questionnaire, and 7.4 out of 10 for the Speech, Spatial, and Qualities of Hearing Scale 12.
CONCLUSION
Participants demonstrated high levels of satisfaction and good hearing performance with RONDO 2, which indicates that this single-unit processor could be a viable and comfortable alternative to behind-the-ear processors in young children, although larger controlled experiments are warranted.
Topics: Adult; Child; Humans; Child, Preschool; Cochlear Implants; Cochlear Implantation; Hearing; Speech Perception; Hearing Tests
PubMed: 38088315
DOI: 10.5152/iao.2023.22979 -
Scientific Reports Aug 2023Electromagnetic wave-based analogue computing has become an interesting computing paradigm demonstrating the potential for high-throughput, low power, and parallel...
Electromagnetic wave-based analogue computing has become an interesting computing paradigm demonstrating the potential for high-throughput, low power, and parallel operations. In this work, we propose a technique for the calculation of derivatives of temporal signals by exploiting transmission line techniques. We consider multiple interconnected waveguides (with some of them being closed-ended stubs) forming junctions. The transmission coefficient of the proposed structure is then tailored by controlling the length and number of stubs at the junction, such that the differentiation operation is applied directly onto the envelope of an incident signal sinusoidally modulated in the time domain. The physics behind the proposed structure is explained in detail and a full theoretical description of this operation is presented, demonstrating how this technique can be used to calculate higher order or even fractional temporal derivatives. We envision that these results may enable the development of further time domain wave-based analogue processors by exploiting waveguide junctions, opening new opportunities for wave-based single operators and systems.
PubMed: 37573358
DOI: 10.1038/s41598-023-40046-3 -
International Journal of Food Science 2022Baobab fruit demand has been on the rise in the recent past, and in an attempt to match the demand, farmers and middlemen are forced to harvest immature fruits which are...
Baobab fruit demand has been on the rise in the recent past, and in an attempt to match the demand, farmers and middlemen are forced to harvest immature fruits which are not fully dried. To ensure an acceptable moisture content, baobab fruits are subjected to solar drying, which is a slow process and often carried out in open and unhygienic conditions raising safety concerns. This study was conducted to investigate the microbial and aflatoxin contamination levels in ready-to-eat baobab products from selected formal and informal processors in specific counties of Kenya. Selected processed baobab products were sampled randomly from formal and informal processors and analyzed for the total aerobic count, Enterobacteriaceae, yeast and molds, ergosterol, aflatoxins, moisture, and water activity. The moisture and water activity of baobab pulp and candies from formal processors ranged between 7.73% and 15.06% and 0.532 and 0.740 compared to those from informal processors which ranged from 10.50% to 23.47% and 0.532 to 0.751, respectively. In this study, baobab pulp from formal processors had significantly ( = 0.0008, 0.0006) lower Enterobacteriaceae and yeast and molds loads (0.7 ± 0.29 and 3.1 ± 0.38 log 10 CFU/g, respectively) than pulp from informal processors (3.1 ± 0.70 and 5.3 ± 0.11 log 10 CFU/g, respectively). Similarly, the Enterobacteriaceae counts of candies from formal processors (nondetectable) were considerably lower ( = 0.015) than those from informal processors (1.8 ± 0.56 log 10 CFU/g). The ergosterol content in these baobab product samples ranged between 0.46 and 1.92 mg/100 g while the aflatoxin content ranged between 3.93 and 11.09 × 103 g/kg, respectively. Fungal and aflatoxin contamination was detected in 25% and 5% of pulp from formal and informal processors, respectively, and in 5% of candies from informal processors. Microbial contamination in processed baobab products shows an unhygienic processing environment while the fungal and aflatoxin contamination may indicate poor postharvest handling, transport, and storage conditions of baobab fruits along the baobab value chain.
PubMed: 35252436
DOI: 10.1155/2022/2577222 -
Sensors (Basel, Switzerland) Jan 2023Synthetic aperture radar (SAR), which can generate images of regions or objects, is an important research area of radar. The chirp scaling algorithm (CSA) is a...
Synthetic aperture radar (SAR), which can generate images of regions or objects, is an important research area of radar. The chirp scaling algorithm (CSA) is a representative SAR imaging algorithm. The CSA has a simple structure comprising phase compensation and fast Fourier transform (FFT) operations by replacing interpolation for range cell migration correction (RCMC) with phase compensation. However, real-time processing still requires many computations and a long execution time. Therefore, it is necessary to develop a hardware accelerator to improve the speed of algorithm processing. In addition, the demand for a small SAR system that can be mounted on a small aircraft or drone and that satisfies the constraints of area and power consumption is increasing. In this study, we proposed a CSA-based SAR processor that supports FFT and phase compensation operations and presents field-programmable gate array (FPGA)-based implementation results. We also proposed a modified CSA flow that simplifies the traditional CSA flow by changing the order in which the transpose operation occurs. Therefore, the proposed CSA-based SAR processor was designed to be suitable for modified CSA flow. We designed the multiplier for FFT to be shared for phase compensation, thereby achieving area efficiency and simplifying the data flow. The proposed CSA-based SAR processor was implemented on a Xilinx UltraScale+ MPSoC FPGA device and designed using Verilog-HDL. After comparing the execution times of the proposed SAR processor and the ARM cortex-A53 microprocessor, we observed a 136.2-fold increase in speed for the 4096 × 4096-pixel image.
Topics: Radar; Aircraft; Algorithms; Cell Movement; Cerebral Cortex
PubMed: 36679756
DOI: 10.3390/s23020959 -
Journal of Agromedicine Oct 2023The Risk Information System for Commercial Fishing (RISC Fishing) merged information on fishermen and vessel incident types from various databases. This descriptive...
OBJECTIVES
The Risk Information System for Commercial Fishing (RISC Fishing) merged information on fishermen and vessel incident types from various databases. This descriptive study examined linked fisherman injury records (fatal and nonfatal) and vessel incident records in Oregon and Washington from 2000 to 2018 in the RISC Fishing database. The circumstances of incidents and any association with fishermen outcomes were explored to identify injury prevention opportunities.
METHODS
The statistical analyses included a descriptive study of incidents related to the injury characteristics and frequency of outcomes by incident type. Further analyses included contingency tables and Pearson Chi-Square tests for selected variables to determine if there were associations between vessel incident outcomes (fatality, nonfatal injury, no injury).
RESULTS
A total of 375 reported incidents with 93 cases of fatalities, 239 nonfatal injuries, and over 6,575 fishermen with no injury were described. Of fatalities, 90% were due to drowning, with only 2% of victims reported donning survival equipment. Deckhands experienced fatal and nonfatal injuries most frequently. The most common factors associated with nonfatal injuries included contact with objects (event), walking on vessel and hauling gear (work activities), and fractures and open wounds (nature). The most common final event leading to a vessel disaster with no injury being reported was sinking (76%). Distributions between the incident outcomes (fatality, nonfatal injury, and no injury) differed by vessel activity/type, fishery/gear, and event leading to the incident.
CONCLUSION
Linked information of fishermen injury outcomes and vessel incident information showed that events and settings that involve fatalities are qualitatively different from incidents resulting in only nonfatal injuries or uninjured survivors. Vessel-level approaches for mitigating fatalities, such as ensuring vessel stability, improving navigation/operation decisions, and spotlighting survival equipment policies/rescue priorities could have a significant impact. Work task-specific prevention strategies for nonfatal injuries related to the larger vessels (catcher/processors and processors) and smaller vessels (with pot/trap gears) are paramount. The use of linked information provided in reports can provide a fuller incident picture to advance efforts to improve the working conditions of commercial fishermen.
Topics: Humans; Accidents, Occupational; Hunting; Oregon; Washington; Fractures, Bone; Wounds and Injuries
PubMed: 37387508
DOI: 10.1080/1059924X.2023.2229827 -
Microbial Biotechnology Mar 2023Biology leverages a range of electrical phenomena to extract and store energy, control molecular reactions and enable multicellular communication. Microbes, in... (Review)
Review
Biology leverages a range of electrical phenomena to extract and store energy, control molecular reactions and enable multicellular communication. Microbes, in particular, have evolved genetically encoded machinery enabling them to utilize the abundant redox-active molecules and minerals available on Earth, which in turn drive global-scale biogeochemical cycles. Recently, the microbial machinery enabling these redox reactions have been leveraged for interfacing cells and biomolecules with electrical circuits for biotechnological applications. Synthetic biology is allowing for the use of these machinery as components of engineered living materials with tuneable electrical properties. Herein, we review the state of such living electronic components including wires, capacitors, transistors, diodes, optoelectronic components, spin filters, sensors, logic processors, bioactuators, information storage media and methods for assembling these components into living electronic circuits.
Topics: Electronics; Synthetic Biology; Electricity; Biotechnology
PubMed: 36519191
DOI: 10.1111/1751-7915.14171