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Research Interests:
This paper has proposed an energy-efficient epilepsy detection framework for embedded systems. The epilepsy detection framework is implemented in 11 layers Convolution Neural Network (CNN) with a 2-stage RISC-V core and a coprocessor to... more
This paper has proposed an energy-efficient epilepsy detection framework for embedded systems. The epilepsy detection framework is implemented in 11 layers Convolution Neural Network (CNN) with a 2-stage RISC-V core and a coprocessor to accelerate CNN inferences. The CNN algorithm provides 97.8% and 93.5% accuracy on floating-point and fixedpoint operations respectively. The proposed CNN coprocessor is designed to offload CNN inference from RISC-V core to hardware with 51 nJ data transfer energy and 0.9 µJ inference energy for each 500 points input data frame. The coprocessor reduces the runtime of CNN inferences over 10^6x to perform only 0.012 s latency for each classification. According to the energy-efficient coprocessor, an AI-based solution is practical for real-time epilepsy detection on wearable devices for consumer electronics.
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During hemodialysis (HD), intradialytic hypotension (IDH) is a serious complication and a major risk factor of mortality. This study aimed to use machine learning to predict IDH occurrence to improve prevention. In the proposed model in... more
During hemodialysis (HD), intradialytic hypotension (IDH) is a serious complication and a major risk factor of mortality. This study aimed to use machine learning to predict IDH occurrence to improve prevention. In the proposed model in this study, we conducted Gated Recurrent Units, Deep Neural Networks, and Long-Short-term Memory models to predict SBP values. For predicting IDH, a binary classification model was established. The results showed an accuracy of 90% with a difference between the predicted and actual value of 25mm- Hg for SBP value prediction. Also, the binary classification model had a threshold of 90mm-Hg with a accuracy of 93% and a specificity of 97%.
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The number of studies on closed-loop detection and electrical stimulation systems [1]–[2] for efficient control of neurological disorders is increasing, because recent clinical studies have shown their efficiency and usefulness in symptom... more
The number of studies on closed-loop detection and electrical stimulation systems [1]–[2] for efficient control of neurological disorders is increasing, because recent clinical studies have shown their efficiency and usefulness in symptom suppression. Electrical stimulation can produce enough stimulation to affect a large range of nerves. However, all nerves near the stimulus are excited and hurt, and over time, currents start to exceed acceptable limits. Therefore, optogenetic stimulation [3]–[4] has become compelling in recent years due to several advantages: (1) no artificial noise on the EEG; (2) ability to stimulate specific nerves; and (3) no injurious effects on nerves. In this study, a wireless programmable stimulating system-on-chip (WPSSoC) is reported that provides wireless open/closed-loop optogenetic and electrical stimulation to improve treatment for epilepsy suppression. The system is demonstrated on programmable stimulation parameters wirelessly controlled by a software Graphical User Interface (GUI) on a computer. Moreover, an animal experiment conducted on optogenetic tissue was successful, thereby demonstrating that the nerve injury on optogenetic stimulation is lower than that of electrical stimulation.
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Research Interests:
Background and Aims In HD treatment, venous needle dislodgement (VND) is a major concern in healthcare systems worldwide. Although VND is not an extremely common occurrence, it could be life-threatening or even cause death. The report of... more
Background and Aims In HD treatment, venous needle dislodgement (VND) is a major concern in healthcare systems worldwide. Although VND is not an extremely common occurrence, it could be life-threatening or even cause death. The report of the Taiwan Patient Safety Reporting System listed the dislodgement of needles, catheters, and similar devices as third among thirteen common incident types that threaten patient safety. Hospitals are jointly liable for the blood leakage and have to provide emergency treatment such as emergency hemostasis, blood transfusion, Erythropoietin (EPO) injection and hospitalization. To a worse extent, hospitals, physicians and paramedics have to face criminal charges and the claims raised by the patients’ families. This study employed digital technology to develop a real-time multi-bed monitoring system to detect fluid leakage and control the state of multi-bed blood leakage simultaneously, allowing paramedics to respond to and solve issues swiftly. The res...
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The impact of leukoaraiosis on the risk of symptomatic intracerebral hemorrhage (SICH) after stroke thrombolysis is conflicting, and the data on Asian populations are lacking. Therefore, in this study, we assessed the association between... more
The impact of leukoaraiosis on the risk of symptomatic intracerebral hemorrhage (SICH) after stroke thrombolysis is conflicting, and the data on Asian populations are lacking. Therefore, in this study, we assessed the association between leukoaraiosis and SICH, and the association between leukoaraiosis and the 90-day functional outcome in the Asian population. Data were collected from a two-center prospective registry of acute ischemic stroke patients given intravenous tissue plasminogen activator between 2006 and 2014. A total of 614 pretreatment brain CT and 455 posttreatment MRI were retrospectively assessed using two different rating scales for the presence of leukoaraiosis. Outcome measures were the occurrence of SICH with three definitions and any hemorrhage after thrombolysis and functional outcome at 3 months. Of the 614 patients assessed, 30.3% showed severe leukoaraiosis on the baseline brain CT. The SICH rate was 4.6% - 7.2% based on different definitions, and overall, 24...
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Nerve conduction block with a high intensity-focused ultrasound (HIFU) transducer has been performed in normal and diabetic animal models recently. HIFU can reversibly block the conduction of peripheral nerves without damaging the nerves... more
Nerve conduction block with a high intensity-focused ultrasound (HIFU) transducer has been performed in normal and diabetic animal models recently. HIFU can reversibly block the conduction of peripheral nerves without damaging the nerves while using an appropriate ultrasonic parameter. Temporary and partial block of the action potentials of nerves shows that HIFU has the potential to be a useful clinical treatment for pain relief. This work demonstrates the procedures for suppressing the action potentials of neuropathic nerves in diabetic rats in vivo using an HIFU transducer. The first step is to generate adult male diabetic neuropathic rats by streptozotocin (STZ) injection. The second step is to evaluate the peripheral diabetic neuropathy in STZ-induced diabetic rats by an electronic von Frey probe and a hot plate. The final step is to record in vivo extracellular action potentials of the nerve exposed to HIFU sonication. The method showed here may benefit the study of ultrasound...
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Research Interests:
The purpose of this study was to investigate the effects of ipsilateral arm movement and contralateral hand grasp on the spastic hand opened by open-loop electrical stimulation. The major problem of applying proper electrical stimulation... more
The purpose of this study was to investigate the effects of ipsilateral arm movement and contralateral hand grasp on the spastic hand opened by open-loop electrical stimulation. The major problem of applying proper electrical stimulation is variable spasticity, the intensity of which changes with posture and movements of other parts of the body. Electrical stimulation was applied to extensor digitorum communis and ulnar nerve to open the affected hand. Different procedures were then used to assess the effects of moving the ipsilateral forearm and contracting the contralateral normal hand. Electrical stimulation opened the spastic hand in more than 95% of trials in all subjects, whether stimulation was applied before or after the movement of the forearm. Moving the ipsilateral forearm did have an effect on opening the hand, and making adjustment of stimulation intensities was necessary in all subjects. The stimulation opened the spastic hand during the contraction of the contralatera...
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Diabetes mellitus can lead to diabetic polyneuropathy (DPN) and cognitive deficits that manifest as peripheral and central neuropathy, respectively. In this study we investigated the relationship between visuospatial working memory (VSWM)... more
Diabetes mellitus can lead to diabetic polyneuropathy (DPN) and cognitive deficits that manifest as peripheral and central neuropathy, respectively. In this study we investigated the relationship between visuospatial working memory (VSWM) capacity and DPN severity, and attempted to improve VSWM in DPN patients via the use of transcranial direct current stimulation (tDCS). Sixteen DPN patients and 16 age- and education-matched healthy control subjects received Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) and Montreal Cognitive Assessment (MOCA) for baseline cognitive assessment. A forward- and backward-recall computerized Corsi block tapping task (CBT), both with and without a concurrent motor interference task was used to measure VSWM capacity. Each DPN patient underwent a pre-treatment CBT, followed by tDCS or sham treatment, then a post-treatment CBT on two separate days. We found that although patients with severe DPN (Dyck's grade 2a or 2b) showed comparable ge...
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A small group of patients with inherited neuropathy that has been shown to be caused by mutations in the BSCL2 gene. However, little information is available about the role of BSCL2 mutations in inherited neuropathies in Taiwan. Utilizing... more
A small group of patients with inherited neuropathy that has been shown to be caused by mutations in the BSCL2 gene. However, little information is available about the role of BSCL2 mutations in inherited neuropathies in Taiwan. Utilizing targeted sequencing, 76 patients with molecularly unassigned Charcot-Marie-Tooth disease type 2 (CMT2) and 8 with distal hereditary motor neuropathy (dHMN), who were selected from 348 unrelated patients with inherited neuropathies, were screened for mutations in the coding regions of BSCL2. Two heterozygous BSCL2 mutations, p.S90L and p.R96H, were identified, of which the p.R96H mutation is novel. The p.S90L was identified in a pedigree with CMT2 while the p.R96H was identified in a patient with apparently sporadic dHMN. In vitro studies demonstrated that the p.R96H mutation results in a remarkably low seipin expression and reduced cell viability. BSCL2 mutations account for a small number of patients with inherited neuropathies in Taiwan. The p.R9...
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Research Interests: Neuroscience, Psychology, Cognitive Science, Transcranial Magnetic Stimulation, Attention, and 15 moreWorking Memory, Medicine, Prefrontal Cortex, Brain and Cognition, Humans, Female, Male, Reaction Time, Young Adult, Transcranial Direct Current Stimulation, Adult, Short Term Memory, Neurosciences, Dorsolateral Prefrontal Cortex, and Neuropsychological Tests
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Identification of genetic mutations has been of burgeoning importance in amyotrophic lateral sclerosis (ALS) in recent years. The aim of this study was to determine the frequency and spectrum of mutations in major ALS-causing genes in a... more
Identification of genetic mutations has been of burgeoning importance in amyotrophic lateral sclerosis (ALS) in recent years. The aim of this study was to determine the frequency and spectrum of mutations in major ALS-causing genes in a Taiwanese ALS cohort of Han Chinese origin. Mutational analyses of the SOD1, TARDBP, FUS, OPTN, VCP, UBQLN2, SQSTM1, PFN1, HNRNPA1, and HNRNPA2B1 genes were carried out by direct sequencing in 161 unrelated patients with ALS, including 30 with familial ALS (FALS) and 131 with sporadic ALS (SALS). The CAG repeat size in ATXN2 and the GGGGCC repeat expansion in C9ORF72 of the patients were also investigated. Mutations were identified in 33 patients (20.5%, 33/161), including 22 with FALS and 11 with SALS. Mutations were identified most frequently in SOD1 (7.5%). Three mutations are novel, including SOD1 p.G10A, SOD1 p.D83N, and OPTN p.L494W. These findings broaden the spectrum of ALS-causing mutations and are indispensable for designing optimal strategies of mutational analysis and genetic counseling of ALS for patients of Chinese origin.
Research Interests: Biology, Medicine, Amyotrophic Lateral Sclerosis, Humans, Mutation, and 15 moreTaiwan, Female, Male, Genetic Association Studies, Proteins, Superoxide Dismutase, Clinical Sciences, Aged, Middle Aged, Adult, Asian Continental Ancestry Group, Neurobiology of Aging, DNA binding proteins, Neurosciences, and Cohort Studies
Research Interests: Neuroscience, Cognitive Science, Computer Science, Neuromuscular Control, Medicine, and 15 moreNeural Prosthesis, High Frequency, Animals, Male, New Zealand, Medical Electronics, Nerve Block, Rabbits, Long Term Effect, Statistical Methods for Neuroscience, Axons, Neurosciences, Tibial nerve, Neuroscience Methods, and Electric stimulation
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... 33, no. 1, pp. 94-102, Oct.2006. [9] A. Drzezga, T. Grimmer, G. Henriksen, I. Stangier, R. Perneczky, J. ehl-Schmid, CA Mathis, WE Klunk, J. Price, S. DeKosky, HJ Wester, M. Schwaiger, and A. Kurz, "Imaging of amyloid plaques... more
... 33, no. 1, pp. 94-102, Oct.2006. [9] A. Drzezga, T. Grimmer, G. Henriksen, I. Stangier, R. Perneczky, J. ehl-Schmid, CA Mathis, WE Klunk, J. Price, S. DeKosky, HJ Wester, M. Schwaiger, and A. Kurz, "Imaging of amyloid plaques and Page 5. ...
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Research Interests:
We report a case with a sequential appearance and disappearance of homonymous hemianopsia, palinopsia and metamorphopsia in the defective visual field within two days. She had a stroke nine months ago and recovered completely. During that... more
We report a case with a sequential appearance and disappearance of homonymous hemianopsia, palinopsia and metamorphopsia in the defective visual field within two days. She had a stroke nine months ago and recovered completely. During that episode, dizziness and unsteadiness happened suddenly and was followed by above-mentioned visual symptoms. Brain image and blood perfusion studies showed an old right occipital lesion with hemodynamic changes. Electroencephalograms performed immediately just after the disappearance of all the above-mentioned symptoms subsided and four months later showed similar findings, some isolated independent sharp waves over bilateral temporal areas, with right posterior extension. These were independent of her visual symptoms. The pathophysiologies of our case could be a sequential hemodynamic change in the right occipital area, from hypoperfusion to transient hyperperfusion and finally to normal perfusion. Potential mechanisms are discussed with literature review.
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Normal brain function depends on normal neuronal metabolism, which is closely related to systemic homeostasis of metabolites, such as glucose, electrolytes, amino acids and ammonia. "Metabolic... more
Normal brain function depends on normal neuronal metabolism, which is closely related to systemic homeostasis of metabolites, such as glucose, electrolytes, amino acids and ammonia. "Metabolic encephalopathy" indicates diffuse brain dysfunction caused by various systemic derangements. Electroencephalogram (EEG) is widely used to evaluate metabolic encephalopathy since 1937, when Berger first observed slow brain activity induced by hypoglycemia. EEG is most useful in differentiating organic from psychiatric conditions, identifying epileptogenicity, and providing information about the degree of cortical or subcortical dysfunction. In metabolic encephalopathy, EEG evolution generally correlates well with the severity of encephalopathy. However, EEG has little specificity in differentiating etiologies in metabolic encephalopathy. For example, though triphasic waves are most frequently mentioned in hepatic encephalopathy, they can also be seen in uremic encephalopathy, or even in aged psychiatric patients treated with lithium. Spike-and-waves may appear in hyper- or hypo-glycemia, uremic encephalopathy, or vitamin deficiencies, etc. Common principles of EEG changes in metabolic encephalopathy are (1) varied degrees of slowing, (2) assorted mixtures of epileptic discharge, (3) high incidence of triphasic waves, and (4), as a rule, reversibility after treatment of underlying causes. There are some exceptions to the above descriptions in specific metabolic disorders and EEG manifestations are highly individualized.
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The present study aimed to describe the day-by-day temporal patterns of body temperatures in acute stroke and to delineate the differences in serial daily changes in body temperatures between intracerebral hemorrhage (ICH) and cerebral... more
The present study aimed to describe the day-by-day temporal patterns of body temperatures in acute stroke and to delineate the differences in serial daily changes in body temperatures between intracerebral hemorrhage (ICH) and cerebral infarct (CI). We retrospectively enrolled 90 patients (32 with ICH and 58 with CI), admitted within 12 hours after the onset of stroke. Body temperatures were measured as the tympanic temperatures during the initial 6 days of hospitalization. Patients with clinical infections were excluded. The severity of stroke was assessed by Scandinavian Stroke Scale (SSS). SSS score < or = 30 was defined as severe stroke, and SSS score >30 as mild-to-moderate stroke. Mean body temperature was significantly higher in patients with ICH than those with CI in 0 approximately 12 hours; 12 approximately 24 hours, 24 approximately 48 hours, and 48 approximately 72 hours (all p<0.05) after the onset of stroke. Among patients with ICH, the body temperature was significantly higher in the severe group than the mild-to-moderate group during 24 approximately 48 hours and 48 approximately 72 hours (both p<0.05) after the onset of stroke. No significant difference in body temperatures was observed between patients with severe stroke and patient with mild-to-moderate CI. The serial time course of body temperature in the acute stage of stroke differs between ICH and CI. This study showed that, in ICH but not in CI, the elevation of body temperature has significant association with the stroke severity. Our results may help in the management of hyperthermia during acute stroke.
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Ramsay Hunt syndrome (RHS) complicated with encephalitis is rare, and the appearance of hemi-motosensory deficit in RHS is even rarer. We reported two such cases. Both patients had a peripheral type facial palsy, facial numbness and... more
Ramsay Hunt syndrome (RHS) complicated with encephalitis is rare, and the appearance of hemi-motosensory deficit in RHS is even rarer. We reported two such cases. Both patients had a peripheral type facial palsy, facial numbness and zoster in the ipsilateral ear canal. The consciousness was clear and cognitive function was normal. The functional deficits of extremities were ipsilateral to the facial palsy in one case, but contralateral in the other. Magnetic resonance imaging of the brain in both cases showed no abnormality. The manifestations were compared with two more cases from the literature.
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Traditional neural stimulation method recruits the muscle nerves in a reverse order of physiologic manner, i.e., can not recruit small diameter nerve fibers without recruiting large diameter ones. However, high frequency blocking... more
Traditional neural stimulation method recruits the muscle nerves in a reverse order of physiologic manner, i.e., can not recruit small diameter nerve fibers without recruiting large diameter ones. However, high frequency blocking technique is a feasible method for achieving selective stimulation and blocking nerve fibers. The aim of the study is to establish an animal model for studying order recruitment
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Aortic dissection, which typically manifests as sudden tearing or migratory pain, is a well-known medical emergency. However, in 5% of aortic dissection patients, there is no pain. In these patients, the diagnosis depends on the... more
Aortic dissection, which typically manifests as sudden tearing or migratory pain, is a well-known medical emergency. However, in 5% of aortic dissection patients, there is no pain. In these patients, the diagnosis depends on the development of neurologic complications. After analyzing the initial symptoms of a series of patients with aortic dissection, we found 4/211 (1.9%) patients suffered from paraparesis. We suggested that the mid- or low thoracic cord be most vulnerable site during acute aortic dissection. This report highlighted the importance of considering the diagnosis of aortic dissection in a patient with a history of acute onset of transient or permanent neurological symptoms in the lower limbs. Whether paraparesis can be an indicator of the prognosis of aortic dissection requires further researches.
Research Interests: Humans, Female, Male, Clinical Sciences, Aged, and 4 moreMiddle Aged, Paraparesis, Aortic Aneurysm, and Neurosciences
Purpose: Symptomatic TN accounts for up to 15% of all TN. Though there are many established "red flag" signs, it is still sometimes difficult to sift symptomatic from classic TN. We herein report two cases of isolated TN with... more
Purpose: Symptomatic TN accounts for up to 15% of all TN. Though there are many established "red flag" signs, it is still sometimes difficult to sift symptomatic from classic TN. We herein report two cases of isolated TN with normal neurologic examinations and then tissue proved as epidermoid cyst. Case Report: Case 1: A 17-year-old girl presented with paroxysmal intense pain mixed dull background pain at right mandibular region for one month. The blink reflex demonstrated brainstem lesion and brain magnetic resonance imaging (MRI) revealed a huge lobulated tumor in right cerebellopontine angle (CPA) with obvious brainstem compression. Her right facial pain was nearly completely disappeared postoperatively. Case 2: The 48-year-old woman had chronic paroxysmal electric-like and burning pain in left V3 region for more than 5 years. Because of refractory pain, brain MRI was arranged and showed a non-enhancing cystic lesion at left CPA. Post operative complications occurred as...
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Primary angiitis of the central nervous system is a rare idiopathic inflammation of vessels. We report on a 75-year-old male with primary angiitis of the central nervous system and cerebral amyloid angiopathy. He presented with subacute... more
Primary angiitis of the central nervous system is a rare idiopathic inflammation of vessels. We report on a 75-year-old male with primary angiitis of the central nervous system and cerebral amyloid angiopathy. He presented with subacute onset of progressive decline in cognitive functions, followed by confusion and coma. Initial brain magnetic resonance imaging favored meningoencephalitis. There was no improvement after treatment with antibiotics. Final diagnosis was proven by brain biopsy. Corticosteroids were given, but without significant improvement. This case is reported because of its rarity and its clinical presentation.
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Internuclear ophthalmoplegia is caused by a lesion; stroke, multiple sclerosis, brain metastases, or trauma may produce lesions of the medial longitudinal fasciculus (MLF). Imaging techniques, such as DWI, can help identify the site of... more
Internuclear ophthalmoplegia is caused by a lesion; stroke, multiple sclerosis, brain metastases, or trauma may produce lesions of the medial longitudinal fasciculus (MLF). Imaging techniques, such as DWI, can help identify the site of the lesion in order to speed diagnosis and lead to appropriate treatment. Over an 8-month period, eight consecutive patients with suspected MLF syndrome (most secondary to ischemic stroke) underwent MRI examinations, including DWI sequencing, at an academic center in Taiwan. In all eight patients, abnormal high-signal lesions were found close to the floor of the fourth ventricle on the dorsal side of the pons. A neuroanatomical comparison showed that the location of the lesions was identical to the anatomical position of the MLF. Using DWI, good clinico-radiological correlation was found in all eight ischemic stroke patients diagnosed with MLF syndrome. DWI may broaden the application of MRI in the diagnosis of MLF syndrome.
Research Interests: Stroke, Humans, Taiwan, Female, Male, and 5 moreMedical Physiology, Aged, Middle Aged, Retrospective Studies, and Syndrome
The main purpose of this study was to develop a better feedback control algorithm for controlling muscle force generated by electrical stimulation via cuff electrodes at nerves. We combined a hybrid amplitude /pulse width modulation... more
The main purpose of this study was to develop a better feedback control algorithm for controlling muscle force generated by electrical stimulation via cuff electrodes at nerves. We combined a hybrid amplitude /pulse width modulation scheme with a fuzzy logic, and created several types of fuzzy controllers approximately equivalent to the linear PI, PD and PID controllers. The controllers were
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Due to the inconvenience in passing bifurcated blood vessels via changing curvature of guide-wires during surgery, active catheter or guide-wire systems are developed recently. For lightweight and large bending deformation, the ionic... more
Due to the inconvenience in passing bifurcated blood vessels via changing curvature of guide-wires during surgery, active catheter or guide-wire systems are developed recently. For lightweight and large bending deformation, the ionic polymer metal composites (IPMCs) have been employed in many biomedical applications. For controlling an IPMCbased active cardiac guide-wire system, the goal of this research is to develop methods that can actuate an IPMC and detect its deformation without extra sensors. The method is to parallel a reference IPMC with an actuated IPMC. Then a mixed driving signal that consisted of high and low frequencies was applied to drive the IPMCs. The low frequency signal makes the IPMC to deform and change its surface electrical resistance, while the high frequency signal retains the deformation information. By utilizing a lock-in amplifier to demodulate the high frequency signal, the deformation can be measured. When low frequency actuation signal is absent, the sensing signal follows the deformation well. However, when sinusoidal or square wave actuation signals of frequency 0.1Hz was applied transient error appeared. The error may due to the mismatch of electric resistances and capacitances between the actuation and reference IPMCs. However, when the frequency of actuating signal was reduced to 0.01Hz, the transient error disappeared. For practical applications like catheter guide wire, a low frequency actuation signal induces a large deformation so the method might be feasible for simultaneously sensing and actuating an IPMC.
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The goal of this study was to investigate the eligibility of using surface electromyography (EMG) as a feedback signal for ankle torque control in both normal and stroke subjects performing ankle joint angle tracking with a rehabilitation... more
The goal of this study was to investigate the eligibility of using surface electromyography (EMG) as a feedback signal for ankle torque control in both normal and stroke subjects performing ankle joint angle tracking with a rehabilitation robot. The potential advantage of using EMG as an estimator of active torque is direct facilitation of torque control of individual muscle. A fuzzy PD+I controller was implemented to control the robot. A static EMG-torque map was constructed at 5 ankle positions experimentally for each subject. The map was interpolated to estimate the active dorsiflexion torque exerted on the ankle from the EMG of tibialis anterior muscle. Both EMG and the output of the torque sensor were acquired and a weighting factor was used to adjust the relative contribution from these two signals for controlling the robot. Six normal subjects and seven stroke patients were recruited. The angle trajectory to be tracked was alternating ramps (3 degrees/s) of dorsiflexion and p...
The population density approach has been used for modeling the dynamics of large-scale neuronal networks to consider the stochastic nature of the signal processing in the brain. From the conservation principle, the time evolution of... more
The population density approach has been used for modeling the dynamics of large-scale neuronal networks to consider the stochastic nature of the signal processing in the brain. From the conservation principle, the time evolution of population density can be described by a nonlinear partial differential equation (PDE). The finite difference method (FDM) has been proposed for solving this PDE. However, FDM is sensitive to the density gradient of the solution and is confined to problems that have a regular state space. An irregular state space is always obtained if realistic neuronal models are considered. In this study, the finite element method (FEM) is formulated to solve this PDE and apply it to solve the orientation tuning problem. The results show that when the state space discretization is coarse, FEM retains high accuracy whereas FDM does not. Furthermore, FEM reduces computation time by 90% compared to that required for FDM. In addition, FEM can easily handle the existence of...
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Purpose: Thermal threshold and thermal pain threshold determinations are part of quantitative sensory tests. Usually the average of many repeated trials is defined as the threshold. The inter-trial interval (ITI) may have an effect on the... more
Purpose: Thermal threshold and thermal pain threshold determinations are part of quantitative sensory tests. Usually the average of many repeated trials is defined as the threshold. The inter-trial interval (ITI) may have an effect on the later trials. The main purpose of this study was to investigate the influence of ITI on the test results. Methods: Forty-two healthy subjects were recruited. The limit method was adopted. Each subject received 4 sessions of testing, with one ITI equal to 10, 20, 40 and 60 seconds, respectively. In each session, all four modalities (warm and cold thresholds and cold and hot pain thresholds) were performed. Thermal thresholds were the averages of four trials and thermal pain thresholds were the averages of three trials. The ITI order and the modality order were pseudo-randomized. Analyses of variance were utilized to test the influence of ITI, the modality order and the trial order. Results: The results implied that the test results by the limit meth...
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wave is the spontaneous EEG activity around 10Hz originating from Rolandic area and is suppressed by voluntary movements. The current study was designed to test whether µ wave was also suppressed by passive movements. The passive... more
wave is the spontaneous EEG activity around 10Hz originating from Rolandic area and is suppressed by voluntary movements. The current study was designed to test whether µ wave was also suppressed by passive movements. The passive movements of right thumb (driven by a custom-made mechanism) of two different frequencies, namely, 5 and 10 Hz, were used as the sensory inputs. Sixteen channels of EEG signals in bilateral central area were recorded with a digital EEG machine with a sampling rate of 256 Hz. Two time-frequency signal processing methods, short time Fourier Transform and wavelet decomposition were employed to analyze the data. Three normal subjects were recruited. The results of both short time Fourier Transform and wavelet decomposition analyses indicated that µ wave on the contralateral somatosensory area was suppressed during passive movements.