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Background: The recommended target low-density lipoprotein cholesterol (LDL-C) level for coronary artery disease (CAD) patients has been lowered from 100 to 70 mg/dL in several clinical guidelines for secondary prevention. We aimed to assess whether initiating statin treatment in CAD patients with baseline LDL-C 70–100 mg/dL in Taiwan could be cost-effective. Methods: A Markov model was developed to simulate a hypothetical cohort of CAD patients with a baseline LDL-C level of 90 mg/dL. The incidence and recurrence of MI and stroke related to specific LDL-C levels as well as the statin effect, mortality rate, and health state utilities were obtained from the literature. The direct medical costs and rate of fatal events were derived from the national claims database. The incremental cost-effectiveness ratio (ICER) per quality-adjusted life years (QALYs) was calculated, and sensitivity analyses were performed. Results: Moderate-intensity statin use, a treatment regimen expected to achieve LDL

Postural orthostatic tachycardia syndrome (POTS) typically occurs in youths, and early accurate POTS diagnosis is challenging. A recent hypothesis suggests that upright cognitive impairment in POTS occurs because reduced cerebral blood flow velocity (CBFV) and cerebrovascular response to carbon dioxide (CO2) are nonlinear during transient changes in end-tidal CO2 (PETCO2). This novel study aimed to reveal the interaction between cerebral autoregulation and ventilatory control in POTS patients by using tilt table and hyperventilation to alter the CO2 tension between 10 and 30 mmHg. The cerebral blood flow velocity (CBFV), partial pressure of end-tidal carbon dioxide (PETCO2), and other cardiopulmonary signals were recorded for POTS patients and two healthy groups including those aged &gt, 45 years (Healthy-Elder) and aged &lt, 45 years (Healthy-Youth) throughout the experiment. Two nonlinear regression functions, Models I and II, were applied to evaluate their CBFV-PETCO2 relationship and cerebral vasomotor reactivity (CVMR). Among the estimated parameters, the curve-fitting Model I for CBFV and CVMR responses to CO2 for POTS patients demonstrated an observable dissimilarity in CBFVmax (p = 0.011), mid-PETCO2 (p = 0.013), and PETCO2 range (p = 0.023) compared with those of Healthy-Youth and in CBFVmax (p = 0.015) and CVMRmax compared with those of Healthy-Elder. With curve-fitting Model II for POTS patients, the fit parameters of curvilinear (p = 0.036) and PETCO2 level (p = 0.033) displayed significant difference in comparison with Healthy-Youth parameters, range of change (p = 0.042), PETCO2 level, and CBFVmax also displayed a significant difference in comparison with Healthy-Elder parameters. The results of this study contribute toward developing an early accurate diagnosis of impaired CBFV responses to CO2 for POTS patients.

To study the impaired cerebral autoregulation mechanism of postural orthostatic tachycardia syndrome (POTS) patients under carbon dioxide, a nonlinear regression model was applied to evaluate their cerebrovascular responses to carbon dioxide (CO 2 ). The cerebral blood flow (CBFV), end-tidal carbon dioxide (${{\text{P}}_{{\text{ETC}}{{\text{O}}_2}}}$), and other cardiopulmonary signals were processed for each subject with a tilt table experiment and hyperventilation. The sigmoidal model for cerebrovascular responses to CO 2 during the hyperventilation phase for POTS patients demonstrated an observable dissimilarity in comparison with control groups of healthy elders and healthy youths, especially in its range of change in CBFV.

Background and aims Renal dysfunction is a potent risk factor for cardiovascular diseases, including stroke. This study aimed to evaluate the impact of admission estimated glomerular filtration rate (eGFR) levels on short-term (1-month) and long-term (1-year) mortality in patients with acute ischemic stroke. Methods From the Taiwan Stroke Registry data, we classified ischemic stroke patients, identified from April 2006 to December 2015, into 5 groups by eGFR at admission: ≥ 90, 60–89, 30–59, 15–29, and Results Among 52,732 ischemic stroke patients, 1480 died within one month. The 1-month mortality rate was over 5-fold greater in patients with eGFR Conclusions After acute ischemic stroke, patients with reduced eGFR are at elevated risks of short-term and long-term deaths in a graded relationship.

We investigated the impact of serum cholesterol levels on 30-day mortality after ischemic stroke in dialysis patients.From the Taiwan Stroke Registry data, we identified 46,770 ischemic stroke cases, including 1101 dialysis patients and 45,669 nondialysis patients from 2006 to 2013.Overall, the 30-day mortality was 1.46-fold greater in the dialysis group than in the nondialysis group (1.75 versus 1.20 per 1000 person-days). The mortality rates were 1.64, .62, 2.82, and 2.23 per 1000 person-days in dialysis patients with serum total cholesterol levels of 120 mg/dL, 120-159 mg/dL, 160-199 mg/dL, and ≥200 mg/dL, respectively. Compared to dialysis patients with serum total cholesterol levels of 120-159 mg/dL, the corresponding adjusted hazard ratios of mortality were 4.20 (95% confidence interval [CI] = 1.01-17.4), 8.06 (95% CI = 2.02-32.2), and 6.89 (95% CI = 1.59-29.8) for those with cholesterol levels of 120 mg/dL, 160-199 mg/dL, and ≥200 mg/dL, respectively.Dialysis patients with serum total cholesterol levels of ≥160 mg/dL or 120 mg/dL on admission are at an elevated hazard of 30-day mortality after ischemic stroke.

Made available in DSpace on 2019-10-04T12:41:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-07-02 National Health and Medical Research Council of Australia Background-The uptake of proven stroke treatments varies widely. We aimed to determine the association of evidence-based processes of care for acute ischemic stroke (AIS) and clinical outcome of patients who participated in the HEADPOST (Head Positioning in Acute Stroke Trial), a multicenter cluster crossover trial of lying flat versus sitting up, head positioning in acute stroke. Methods and Results-Use of 8 AIS processes of care were considered: reperfusion therapy in eligible patients; acute stroke unit care; antihypertensive, antiplatelet, statin, and anticoagulation for atrial fibrillation; dysphagia assessment; and physiotherapist review. Hierarchical, mixed, logistic regression models were performed to determine associations with good outcome (modified Rankin Scale scores 0-2) at 90 days, adjusted for patient and hospital variables. Among 9485 patients with AIS, implementation of all processes of care in eligible patients, or defect-free care, was associated with improved outcome (odds ratio, 1.40; 95% CI, 1.18-1.65) and better survival (odds ratio, 2.23; 95% CI, 1.62-3.09). Defect-free stroke care was also significantly associated with excellent outcome (modified Rankin Scale score 0-1) (odds ratio, 1.22; 95% CI, 1.04-1.43). No hospital characteristic was independently predictive of outcome. Only 1445 (15%) of eligible patients with AIS received all processes of care, with significant regional variations in overall and individual rates. Conclusions-Use of evidence-based care is associated with improved clinical outcome in AIS. Strategies are required to address regional variation in the use of proven AIS treatments. Univ New South Wales, Fac Med, George Inst Global Hlth, Sydney, NSW, Australia Ctr Estudios Clin, Inst Ciencias & Innovac Med, Santiago, Chile Clin Alemana Univ Desarrollo, Fac Med, Serv Neurol, Dept Neurol & Psiquiatria, Santiago, Chile Peking Univ, Hlth Sci Ctr, George Inst Global Hlth, Beijing, Peoples R China Australian Catholic Univ, Nursing Res Inst, St Vincents Hlth Australia Sydney, Sydney, NSW, Australia Univ Cent Lancashire, Fac Hlth & Wellbeing, Preston, Lancs, England Univ Chile, Fac Med, Dept Ciencias Neurol, Santiago, Chile Univ Sao Paulo, Ribeirao Preto Med Sch, Stroke Serv Neurol Div, Ribeirao Preto, Brazil Fukuoka Univ, Fac Med, Dept Prevent Med & Publ Hlth, Fukuoka, Fukuoka, Japan Univ Leicester, Dept Cardiovasc Sci, Leicester Biomed Res Ctr, Leicester, Leics, England Univ Leicester, Natl Inst Hlth Res, Leicester Biomed Res Ctr, Leicester, Leics, England Univ Edinburgh, Ctr Clin Brain Sci, Edinburgh, Midlothian, Scotland George Inst Global Hlth, Sydney, NSW, Australia Univ Desarrollo, Serv Neurol, Dept Neurol & Psiquiatria Clin Alemana Santiago, Santiago, Chile St Vincents Hlth Australia Sydney, Sydney, NSW, Australia Australian Catholic Univ, Sydney, NSW, Australia Univ Cent Lancashire, Stroke Practice Res Unit, Sch Hlth, Lancashire Clin Trials Unit, Preston, Lancs, England Univ Leicester, Dept Cardiovasc Sci, Cardiovasc Res Ctr, British Heart Fdn, Leicester, Leics, England Univ Kelaniya, Dept Pharmacol, Fac Med, Colombo, Sri Lanka Christian Med Coll & Hosp, Dept Neurol, Ludhiana, India Kaohsiung Med Univ & Hosp, Dept Neurol, Kaohsiung, Taiwan Linkou Chang Gung Mem Hosp, Dept Neurol, Taipei, Taiwan Peking Union Med Coll Hosp, Beijing, Peoples R China Univ Sao Paulo, Ribeirao Preto Sch Med, Ribeirao Preto, Brazil Monash Univ, Dept Epidemiol & Prevent Med, Melbourne, Vic, Australia Univ Cent Lancashire, Sch Hlth Sci, Coll Hlth & Wellbeing, Preston, Lancs, England Univ Desarrollo, Santiago, Chile Univ New South Wales, Neurosci Res Australia, Sydney, NSW, Australia Natl Univ Singapore, Dept Pharmacol, Singapore, Singapore Bradford Royal Infirm, Bradford Inst Hlth Res, Leeds, W Yorkshire, England Christian Med College, Ludhiana, Punjab, India RemediumOne Pvt Ltd, Kandy, Sri Lanka Kaohsiung Med Univ, Chung Ho Mem Hosp, Kaohsiung, Taiwan Calvary Publ Hosp Bruce, Bruce, Australia Royal North Shore Hosp, St Leonards, NSW, Australia Royal Prince Alfred Hosp, Camperdown, NSW, Australia Concord Repatriat Gen Hosp, Camperdown, NSW, Australia Fiona Stanley Hosp, Camperdown, NSW, Australia Macquarie Base Hosp, Melbourne, Vic, Australia Univ Sao Paulo, Fac Med Ribeirao Preto, Hosp Clin, Sao Paulo, Brazil Hosp Governador Celso Ramos, Florianopolis, SC, Brazil Sao Paulo State Univ, Hosp Fac Med Botucatu, UNESP, Sao Paulo, Brazil Yangquan Coalmine Grp Gen Hosp, Yangquan, Peoples R China Nanjing Med Univ, Nanjing Hosp 1, Nanjing, Jiangsu, Peoples R China 85 Hosp Peoples Liberat Army, Beijing, Peoples R China Chifeng Univ, Affiliated Hosp, Chifeng, Peoples R China Beijing Pinggu Hosp, Beijing, Peoples R China Wenzhou Med Univ, Affiliated Hosp 1, Wenzhou, Peoples R China Soochow Univ, Affiliated Hosp 2, Suzhou, Peoples R China Hebei Med Univ, Hosp 3, Shijiazhuang, Hebei, Peoples R China Capital Med Univ, Xuanwu Hosp, Beijing, Peoples R China Jining Med Univ, Affiliated Hosp, Jining, Peoples R China Third Peoples Hosp Huizhou, Huizhou, Peoples R China Second Cangzhou Cent Hosp, Cangzhou, Peoples R China Shanghai Jiao Tong Univ, Hosp Affiliated, Sch Med, Shanghai, Peoples R China Baogang Hosp, Baotou, Peoples R China Harbin Med Univ, Affiliated Hosp 1, Harbin, Heilongjiang, Peoples R China Shanghai Jiao Tong Univ Sch, Tong Ren Hosp, Peoples Hosp Hejian City, Shanghai, Peoples R China Peking Univ, Shougang Hosp, Beijing, Peoples R China Guangzhou Med Univ, Affiliated Hosp 3, Guangzhou, Guangdong, Peoples R China Second Hosp Nanchang, Nanchang, Jiangxi, Peoples R China Bethune Int Peace Hosp, Beijing, Peoples R China Hua Henan Prov Peoples Hosp, Beijing, Peoples R China Hua Henan Prov Peoples Hosp, Zhengzhou, Henan, Peoples R China Shanghai Jiao Tong Univ, Sch Med, Shanghai Ninth Peoples Hosp, Shanghai, Peoples R China Shijiazhuang Cent Hosp, Shijiazhuang, Hebei, Peoples R China Hosp Base San Jos de Osorno, Osorno, Chile Christian Med Coll & Hosp, Ludhiana, Punjab, India Unit Narayana Hrudayalaya Ltd, Mazumdar Shaw Med Ctr, Bangalore, Karnataka, India Dr Ramesh Cardiac & Multispecial Hosp Pvt Ltd, Guntur, India Post Grad Inst Med Educ & Res, Chandigarh, India Baby Mem Hosp Ltd, Calicut, Kerala, India Sree Chitra Tirunal Inst Med Sci & Technol, Thiruvananthapuram, Kerala, India Sri Jayawardenepura Gen Hosp, Sri Jayawardenepura Kott, Sri Lanka Colombo North Teaching Hosp, Colombo, Sri Lanka Colombo South Coching Hosp, Colombo, Sri Lanka Linkou Chang Gung Mem Hosp, Taoyuan, Taiwan Taipei Med Univ, Shuang Ho Hosp, Taipei, Taiwan En Chu Kong Hosp, New Taipei, Taiwan Natl Cheng Kung Univ Hosp, Tainan, Taiwan Queen Alexandra Hosp, Portsmouth, Hants, England Portsmouth Hosp NHS Natl Hlth Serv iTrust, Portsmouth, Hants, England Univ Coll London Hosp NHS Fdn Trust, London, England Univ Hosp Birmingham NHS Fdn Trust, Queen Elizabeth Hosp Birmingham, Birmingham, W Midlands, England Southend Univ Hosp NHS Fdn Trust, Southend On Sea, England Kings Coll Hosp London, London, England York Teaching Hosp NHS Fdn Trust, York, N Yorkshire, England Nottingham Univ Hosp NHS Trust, Nottingham, England Blackpool Teaching Hosp NHS Fdn Trust, Blackpool, England Gloucestershire Hosp NHS Fdn Trust, Gloucestershire Royal Hosp, Gloucester, England Teaching Hospi NHS Fdn Trust, London, England Royal Cornwall Hosp NHS Trust, Truro, England Royal London Hosp, Barts Hlth NHS Trust, London, England Sheffield Teaching Hosp NHS Fdn Trust, Sheffield, S Yorkshire, England Cambridge Univ Hosp NHS Fdn Trust, Addenbrookes Hosp, Cambridge, England Royal Victoria Hosp, Belfast Hlth & Social Care Trust, London, England Pinderfields Gen Hosp, Mid Yorkshire Hosp NHS Trust, Wakefield, England Royal Devon & Exeter NHS Fdn Trust, London, England Bradford Teaching Hosp NHS Fdn Trust, Bradford, W Yorkshire, England Great Western Hosp NHS Fdn Trust, Swindon, Wilts, England Watford Dist Gen Hosp, Watford, England Imperial Coll Healthcare NHS Trust, London, England Medway NHS Fdn Trust, Gillingham, England Royal Liverpool & Broadgreen Univ NHS Trust, Liverpool, Merseyside, England Calderdale & Huddersfield NHS Fdn Trust, Huddersfield, W Yorkshire, England Hywel Dda Univ Hlth Board, Haverfordwest, Wales Chesterfield Royal Hosp NHS Fdn Trust, Calow, England Luton & Dunstable Univ Hosp NHS Fdn Trust, Luton, Beds, England Countess Chester Hosp NHS Fdn Trust, Chester, Cheshire, England Peterborough City Hosp, Peterborough, Cambs, England Univ Hosp Leicester NHS Trust, Leicester Royal Infirm, Leicester, Leics, England Dist Hosp NHS Fdn Trust, London, England Barnsley Hosp NHS Fdn Trust, Barnsley, England Dorset Cty Hosp NHS Fdn Trust, Dorchester, England Royal Bournemouth & Christchurch Hosp NHS Fdn Tru, Royal Bournemouth Hosp, Bournemouth, Dorset, England Southern Hlth & Social Care Trust, Craigavon Area Hosp, Portadown, England United Lincolnshire Hosp NHS Trust, Pilgrim Hosp, Lincoln, England Bedford Hosp NHS Trust, Bedford, England Sao Paulo State Univ, Hosp Fac Med Botucatu, UNESP, Sao Paulo, Brazil National Health and Medical Research Council of Australia: 1066966

In this paper, with the use of noninvasive TCD, Finapres, and Capnography, we investigated the cerebrovascular response to CO 2 in PD patients and explored the interaction between cerebral autoregulation and ventilatory control by using nonlinear regression model. The results of these patients were compared with those of healthy subjects by examining their CBFV, CVMR (cerebrovascular Vasomotor Reactivity), and CVC i (cerebrovascular conductance index) responses to CO 2 . Statistical analysis of significance values between PD patients and healthy groups was evaluated. The results showed that the PD patients demonstrated a significantly lower level of CBFV max (%) than the healthy elders with nonlinear regression model.

Background and Purpose— The study aimed to assess whether onset headache is an ominous sign in patients with first-ever ischemic stroke. Methods— A large population of ischemic stroke patients was obtained from the Taiwan Stroke Registry. Stroke subtypes were classified by the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) criteria. On the basis of the International Classification of Headache Disorders, second version, onset headache was defined as a new headache that developed at the onset of ischemic stroke. Clinical features and impact on stroke outcomes, including in-hospital stroke in evolution, changes in National Institutes of Health Stroke Scale on discharge, and Barthel index and modified Rankin scale ≤6 months after stroke were compared between those with and without onset headache. Results— Among 11 523 patients with first-ever ischemic stroke, 848 had onset headache (7.4%). Patients with specific cause, large-artery atherosclerosis, or cardioembolism were more likely to have onset headache. Patients with onset headache were younger, predominantly female, and more likely to have posterior circulation ischemic lesions. Compared with patients without onset headache, those with onset headache had a lower frequency of stroke in evolution (4.5% versus 6.7%; adjusted relative risk, 0.64; 95% confidence interval, 0.52–0.79), greater improvement in National Institutes of Health Stroke Scale score on discharge (0.08 versus −0.20; P =0.02), higher mean Barthel index scores (86.5±20.0 versus 83.9±23.3; adjusted difference, 1.43; 95% confidence interval, 0.28–2.89), and a lower frequency of modified Rankin scale higher than 2 (27.6% versus 31.5%; adjusted relative risk, 0.85; 95% confidence interval, 0.72–0.95) at 1-month follow-up. There was also a trend for better functional outcome in 3- and 6-month follow-ups. Conclusions— By adopting standard classification criteria, this large-scale study demonstrated that onset headache was associated with modest but significantly better outcomes after ischemic stroke.

Current paper focus on Parkinson's patients with autonomic dysfunction and how their interactions between cerebral autoregulation and ventilatory control are affected. The experimental data of dynamic CA assessment from the ANS Laboratory of CCGH was accessed for further processing and analysis. The subjects were classified into the groups of healthy and with Parkinson's disease. Based on the accessed ventilation and CBF data, the percentage changes in ventilation and CBF responses to PETCO2 were examined. To minimize effects of changes in ABP on cerebral vasomotor reactivity (CVMR) estimation, cerebrovascular conductance index (CVCi) was calculated, and CBFV-PETCO2 and CVCi-PETCO2 relationships were quantified by nonlinear logistic regression. The interaction between ventilation responses and CBF autoregulation will be modeled and parameters will be validated.

Background Discharge disposition planning is vital for poststroke patients. We investigated clinical factors associated with discharging patients to nursing homes, using the Taiwan Stroke Registry data collected from 39 major hospitals. Methods We randomly assigned 21,575 stroke inpatients registered from 2006 to 2008 into derivation and validation groups at a 3-to-1 ratio. We used the derivation group to develop a prediction model by measuring cumulative risk scores associated with potential predictors: age, sex, hypertension, diabetes mellitus, heart diseases, stroke history, snoring, main caregivers, stroke types, and National Institutes of Health Stroke Scale (NIHSS). Probability of nursing home care and odds ratio (OR) of nursing home care relative to home care by cumulative risk scores were measured for the prediction. The area under the receiver operating characteristic curve (AUROC) was used to assess the model discrimination against the validation group. Results Except for hypertension, all remaining potential predictors were significant independent predictors associated with stroke patient disposition to nursing home care after discharge from hospitals. The risk sharply increased with age and NIHSS. Patients with a cumulative risk score of 15 or more had an OR of 86.4 for the nursing home disposition. The AUROC plots showed similar areas under curves for the derivation group (.86, 95% confidence interval [CI], .85-.87) and for the validation group (.84, 95% CI, .83-.86). Conclusions The cumulative risk score is an easy-to-estimate tool for preparing stroke patients and their family for disposition on discharge.

In this study, time, frequency domain analyses and cross-correlation function (CCF) were applied to evaluate the relationship between systolic arterial blood pressure and mean heart rate signals acquiring from healthy subjects and hypertension patients both in supine and head-up tilt positions to evaluate the effect of antihypertensive drug treatment on baroreflex. 11 hypertension patients (50.1±10.3 years) and 11 healthy subjects (58.4±8.4 years) were included in this study. Results revealed that baroreflex before treatment, cardiacbaroreceptor sensitivity (BRS) values in healthy subjects were significantly higher (p 0.05). It might indicate hypertension could affect baroreflex function but the treatment could lead the function of baroreflex tend to those in healthy groups. The values of α index indicated the significant difference (p 0.05). However, max CCF index (sec) reduced significantly (p

Improving the quality of sleep is an important issue for many researches. A number of biomedical signals, such as EEG, EMG, and EOG were used to classify sleep stages. Based on those signals, one can detect and diagnose the sleep related disorders. There were many researches focused on automatic sleep stages classification. In this research, a new classification method is presented by applying Elman neuron network combined with fuzzy rules and features are extracted by wavelets packets. Nine subjects were recruited from Cheng-Ching General Hospital, Taichung, Taiwan. The sampling frequency is 250Hz and the single channel (C3-A1) EEG signal was acquired for each subject. Combined network was used to recognize the sleep stages in each epoch (a 10 second segment data). The classification results relied on the strong points of neural network and fuzzy logic with average sensitivity is 88.48%, average specificity achieves 95.96%, and average accuracy is 93.79%. The data samples and the length of sleep intervals will be increased for experiment in the future to improve the accuracy.

In this study, cross-correlation function (CCF) were applied to assess the correlation between systolic arterial blood pressure and mean heart rate signals acquiring from stroke and hypertension patients both in supine and head-up tilt positions to evaluate the difference of high blood pressure on baroreflex. 11 hypertension patients (50.1±10.3 years) and 10 stroke patients (56.0±10.1 years) were included in this study. Mean arterial blood pressure level in these two group did not show significant difference (stroke: supine: 117.99 mmHg; tilt:112.25mmHg,; hypertension: supine:107.04 mmHg; tilt: 105.54mmHg, p>0.05). Results revealed that cardiac-baroreceptor sensitivity (BRS) and α index values in these two groups were not significantly different (p>0.05) during supine and headup tilt positions. However, α index values in stroke and hypertension patients reduced in response to head-up tilt (stroke: supine:10.21; tilt:7.14, p

In this study, time and frequency domain analyses were applied to evaluate the relationship between arterial blood pressure and mean heart rate signals acquiring from healthy subjects and hypertension patients both in supine and head-up tilt positions to evaluate the effect of posture change on baroreflex. 11 hypertension patients (50.1±10.3 years) and 11 healthy subjects (58.4±8.4 years) were included in this study. Results revealed that the mean arterial blood pressure (MABP) values of hypertension patients in response to posture changes were maintained (average BP; supine: 104.7±20.2mmHg, tilt: 104.8±19.0 mmHg). However, MABP values in healthy subjects were become higher in head-up tilt position (average BP; supine: 88.3±8.2 mmHg, tilt: 95.3±11.7 mmHg). Both of MABP values of healthy subjects in supine and head-up tilt positions were significantly lower than those in hypertension patients (p

Parkinson’s disease cases have been on the rise in the recent years, which promoted several different researches into the disorder. However, there hasn’t much research been done in the non-motor aspects of the disease. This study aims to improve the understanding of one of the non-motor symptoms of Parkinson’s disease. Specifically, this research aims to further understand cerebral autoregulation in patients with Parkinson’s disease. In order to achieve this aim, 25 subjects were recruited, with 11 healthy controls and 14 patients with Parkinson’s disease. The continuous blood pressure and continuous cerebral blood flow velocity of all subjects were recorded and processed while the subjects were at rest, tilt-up, and during hyperventilation. Linear signal and system analysis techniques were applied such as the power spectral density analysis and cross-correlation function analysis. Results showed that patients with Parkinson’s disease did not show a significant difference from the control group while at rest and after tilt-up. However, there was a significant difference between the groups during hyperventilation. The results obtained in this study suggested that the metabolic regulatory pathway for cerebral autoregulation is impaired in patients with Parkinson’s disease.

n this study, we investigate the feasibility of using power spectral density (PSD) analysis to assess the healthy subjects and diabetics with mild, moderate and severe autonomic neuropathy. Continuous cerebral blood flow velocity (CBFV) was measured using transcranial Doppler ultrasound (TCD), and continuous arterial blood pressure (ABP) was measured using Finapres device under supine and hyperventilation conditions. Four groups of subjects were recruited in this study including 11 healthy adults (56.4±8.1 years), 15 diabetics with mild autonomic neuropathy (50.8±15.7 years), 21 diabetics with moderate autonomic neuropathy (61.8±9.0 years), and 25 diabetics with severe autonomic neuropathy (61.4±10.0 years). According to the results of PSD, it can be speculated that while the diabetic autonomic neuropathy of a patient becomes more serious, the function of cerebral auto regulation (CA) tends to be more imbalance. In conclusion, sympathetic activity was different on diabetics with autonomic neuropathy from supine to hyperventilation by the analysis of power spectrum. Sympathetic activity was increased to reduce CBFV from supine to hyperventilation. Due to hyperventilation make oxygen increase in the brain, cerebral auto regulation can make sympathetic activity increased. Therefore, power spectral analysis can be a useful tool to investigate autonomic neuropathy in diabetics.

To develop a simulation and control mechanism for mechanical ventilator of respiratory therapy is aimed as the continuous mandatory ventilation mode is also objected for study. Based on the optimal chemical-mechanical respiratory control model, sinusoidal waveform which is commonly utilized in clinical applications of volume-targeted approach is modeled and optimized. To meet the needs for ventilation by considering both the chemical and mechanical cost, the effort of breathing for simulated patient under mechanical ventilation is minimized through the optimization tool. The experiments are performed and the resultant waveforms are examine under various simulations of muscular exercise, CO2 inhalation, and resistive and elastic loading for simulate patient. The system is found to perform properly as the resultant ventilatory responses and optimized waveforms are examined through an implemented MATLAB® Graphic User Interface.

In this study, we investigate the feasibility of using the linear cross-correlation function (CCF) and nonlinear correlation dimension (CD) features of mean arterial blood pressure (MABP) and mean cerebral blood flow velocity (MCBFV) as a signature to classify diabetics with various degrees of autonomic neuropathy. 72 subjects were recruited. For each subject, continuous CBFV was measured using a Transcranial Doppler ultrasound, and continuous ABP recorded using a Finapres device in supine position. The CCFs and CDs of pre-filtered spontaneous MABP and MCBFV were computed. Twelve CCF features and one CD feature were extracted from three frequency ranges: very low frequency (VLF, 0.015-0.07Hz), low frequency (LF, 0.07-0.15 Hz), and high frequency (HF, 0.15-0.40Hz). The feature vectors are classified using a support vector machine (SVM) classifier; and a classification rate of 91.67% is obtained under the leave-one-out cross validation evaluation scheme. This very encouraging result indicates that the proposed linear and nonlinear features between MABP and MCBFV can be effective features to discriminate diabetic patients with autonomic neuropathy.

Atherosclerosis of the intracranial arteries is a well-recognized cause of ischemic stroke in Asians, and extracranial carotid artery disease is more often seen in western countries. The relationship of common carotid artery intima-media thickness (CCA-IMT), intracranial arteries stenosis (ICS) and vascular cognitive impairment (VCI) after ischemic stroke has not been fully elucidated. In this study, we investigated the relationship between CCA-IMT and the severity of ICS and VCI.We recruited patients from December 2004, to June 2005, with the inclusion criteria: (1) first-ever ischemic stroke, (2) admission within 3 days of stroke onset, (3) under 80 years old, and (4) no previous dementia history. We excluded patients with stroke scores greater than an NIHSS of 15; those with recurrent stroke, and those with extracranial internal carotid artery stenosis50%. All the patients underwent brain MR angiography, carotid ultrasonography and neuropsychological testing during hospitalization and at 3 months after stroke. We defined the percent of ICS using the method of Warfarin-Aspirin Symptomatic Intracranial Disease. Measurement of CCA-IMT was made on the far wall of the common carotid artery, 1.5 cm proximal to the bifurcation at a point free of plaques. Cognitive performance was assessed using the Cognition Assessment State Instrument (CASI).Thirty patients (21M/9F, mean age 65.97 +/- 10.33 years) were studied. The initial CCA-IMT was 1.04 +/- 0.59 mm and the initial CASI was 64.73 +/- 14.75. The ICS was 70 +/- 26%. At 3 months after stroke, the CCA-IMT was 1.06 +/- 0.59 mm; and CASI was 70.07 +/- 18.50. Compared with patients with CCA-IMT0.87 mm, those with CCA-IMTor = 0.87 mm had lower ICS (57 +/- 23% vs. 81 +/- 24%, p = 0.013), but similar initial CASI score (67.92 +/- 13.52 vs. 61.93 +/- 16.64, p = 0.28). The improvement of CASI score at 3 months was significantly higher in patients with CCA-IMTor = 0.87 mm (67.92 +/- 13.52 vs. 77.36 +/- 14.12, p = 0.001), than those with CCA-IMT0.87 mm (61.93 +/- 16.64 vs. 63.69 +/- 19.89, p = 0.612).CCA-IMT might be associated with the severity of ICS and VCI at 3 months after the first-ever ischemic stroke. The patients with lower CCA-IMT had a better CASI evaluation at 3 months after stroke. A larger scale of study to explore the association of CCA-IMT, VCI and ICS at 3 months after stroke might help farther delineation of these relationships.

Mean arterial blood pressure (MABP) and mean cerebral blood flood velocity (MCBFV) were analyzed by cross-correlation functions (CCFs) in hypertensive patients. Two antihypertensive drugs, Cozaar and Renitec, were adopted to investigate the effects on cerebral autoregulation (CA). Seventeen hypertensive patients were chosen and separated randomly into two groups. The other group was recruited with nine age-matched normal subjects. MABP and MCBFV were acquired during both supine and tilting positions before and after 2 months treatment. Crosscorrelation functions were applied to evaluate CA. During supine position, the results showed that the mean value of max CCF indices in the group of patients before Renitec treatment was significantly different (p < 0.05) from those after 2 months treatment. It might indicate that time lag (generally existed for normal subjects) was improved after treatment. However, these two groups did not exist significant difference comparing with the group of normal subjects before and after treatment. On the other hand, during tilting position, the results revealed that the mean value and coefficient of variation of max CCF values in the group with Cozaar were significantly different (p < 0.05) after treatment. In the group with Renitec, it also revealed that coefficient of variation of max CCF values was significantly different (p < 0.05) after treatment. It might indicate that the correlation between MABP and MCBFV was increased and became more stable after 2 months treatment. Although the mean value of max CCF times and indices in the group with Renitec and the mean value of max CCF values in the group with Cozaar were significantly different (p < 0.05) from normal subjects during tilt-up position before treatment, it makes no significant difference between patients and normal subjects after treatment. Therefore, the CCFs analysis revealed that the CA conditions of patients will tend to be normal with these two antihypertensive drugs after treatment.

Cerebral autoregulation (CA) was assessed by chaotic analysis based on mean arterial blood pressure (MABP) and mean cerebral blood flow velocity (MCBFV) in 19 diabetics with autonomic neuropathy (AN) and 11 age-matched normal subjects. MABP in diabetics dropped significantly in response to tilting (91.6 +/- 14.9 vs. 74.1 +/- 13.4 mmHg, P0.05). Valsalva ratio of heart rate was reduced in diabetics compared to normal (1.1 +/- 0.1 vs. 1.5 +/- 0.2, P0.05). It indicated AN affects the vasomotor tone of peripheral vessels and baroreflex. Nonlinear results showed higher correlation dimension values of MABP and MCBFV in diabetics compared to normal, especially MABP (3.7 +/- 2.3 vs. 2.0 +/- 0.8, P0.05). It indicated CA is more complicated in diabetics. The lower Lyapunov exponent and the higher Kolmogorov entropy values in diabetics indicated less predictable behavior and higher chaotic degree. This study suggests impaired autoregulation would be more chaotic and less predictable.

Mean arterial blood pressure (MBP) was anabzed by spectral and chaotic anabses in hypertensive patients. Two antihypertensive drugs, Cozaar and Renifec, were adopted to investigate the efects on U B P . 17 subjects were separated randomly into two groups. MBP was acquired during both supine and tilt-up positions before and after treatment. Correlation dimension (CO/ was applied to evaluate the complexify of MBP. In spectral analysis, the ratio of low- to high-frequency power was increased more in the group with Renitec. It may indicate that Cozaar has more manijesf effect for suppressing the activiv of sympathetic nervous system. In [he iwo groups. CD values of WBP increased in the supine position. The nonlinear analysis results might reveal that patients will tend to be noma1 with the two drugs. Keyword: mean arterial blood pressure (MBP), spectral analysis, chaos, correlation dimension (CO)

Background The relationship between the striatal dopaminergic system and cardiovascular activity is not well known. The aim of this study is to investigate the relationship between striatal D2/D3 receptor binding and cardiovascular activity. Methods The striatal D2/D3 receptor binding of 34 healthy volunteers was assessed by the single-photon emission computed tomography (SPECT) imaging method with the [123I]-iodobenzoamide (IBZM) ligand. The ratio of the radioactivity in the striatum (St) and the frontal cortex (Fc) (St/Fc ratio) was used as the marker for striatal D2/D3 receptor binding. Their cardiac autonomic functions were measured by continuously monitoring their heart rate and blood pressure (BP) in supine position during 10 min. The heart rate variability (HRV) was analyzed by spectral analysis and the geometric method. Results The St/Fc ratio of striatal dopamine D2/D3 receptor binding correlated negatively with heart rate (HR), and positively with cardiac vagal index (CVI) and low frequency (LF) power in healthy subjects who were in a supine resting position. Conclusions Striatal dopamine D2/D3 receptors may play a part in cardiovascular regulation.

Background: Sensitive and real-time methods are required to characterize the symptoms and resolve the complicated pathology of hypohidrosis. Method: We constructed a conductometric humidity sensor and a stopped-flow manifold with suitable dynamic range for monitoring impaired perspiration. The mini-sensor was coated with a water-absorbing polymer of poly-(2-acrylamido-2-methylpropane sulfonate). Results: Perspiration from palms of normal individuals and hypohidrosis patients were monitored and compared. Tangent slopes of the sensorograms were capable of discriminating hypohidrosis patients from normal individuals. Conclusion: The conductometric min-sensor and the stopped-flow manifold were proven to be useful as a diagnostic tool for hypohidrosis.

The authors use a personal computer combined with a general-purpose data acquisition board and LabVIEW environment to develop techniques for acquiring physiological signals which include HR, BP (systolic pressure, mean pressure and diastolic pressure) and pulse signals from Finapres. These acquired signals can then be recorded, stored and analyzed simultaneously in real time. The techniques presented in this paper include the removal of servo components from the pulse signals of Finapres, and the reduction of respiratory effect in pulse signals using a Wiener filter. These techniques can afford valuable information to understand central autonomic regulatory mechanisms by clinical experiments.

Independent component analysis (ICA) has been proven to be a powerful tool for removing artifacts from electroencephalogram (EEG) recordings in the form of blind source separation (BSS). Independent components (ICs) come from undesired sources that are mixed with the useful signal, and the assessment of such ICs allows them to be detected. But the unwanted ICs also can contain some useful information. To overcome this problem, wavelet-enhanced ICA (wICA) can be used, and this method applies a wavelet threshold for each wavelet coefficient to suppress abnormal deformation in each wavelet coefficient. Using the wICA algorithm to suppress artifacts provides an EEG signal with less distortion in the amplitude and in the phase of the cerebral part of the EEG, and the cerebral part of the EEG can be estimated and obtained very similar to control conditions. However, the EEG signals are affected by various artifact components, and those that have the greatest influence are electromyography (EMG) and electrooculography (EOG). These artifacts may appear simultaneously, randomly or interruptedly, so a fixed threshold level is not really appropriate. We proposed a system including wICA integrated with an adaptive filter model, and this combination system can provide the best prediction of the impacts of artifacts to set up a threshold value that is adaptive and suitable. Our experimental results showed that are approach provided better rejection of artifacts than the wICA system.

Recognition of sleep stages is an important task in the assessment of the quality of sleep. Several biomedical signals, such as EEG, ECG, EMG and EOG are used extensively to classify the stages of sleep, which is very important for the diagnosis of sleep disorders. Many sleep studies have been conducted that focused on the automatic classification of sleep stages. In this research, a new classification method is presented that uses an Elman neural network combined with fuzzy rules to extract sleep features based on wavelet decompositions. The nine subjects who participated in this study were recruited from Cheng-Ching General Hospital in Taichung, Taiwan. The sampling frequency was 250 Hz, and a single-channel (C3-A1) EEG signal was acquired for each subject. The system consisted of a combined neural network and fuzzy system that was used to recognize sleep stages based on epochs (10-second segments of data). The classification results relied on the strong points of combined neural network and fuzzy system, which achieved an average specificity of approximately 96% and an average accuracy of approximately 94%.

Time domain cross-correlation analysis of pre-filtered mean arterial blood pressure (MABP) and mean cerebral blood flow velocity (MCBFV) was applied to assess the cerebral autoregulation (CA). Beat-to-beat time series of spontaneous arterial blood pressure and cerebral blood flow velocity were obtained from 13 young normal volunteers with the Finapres device and the transcranial Doppler for periods of approximately 5 min in the supine position. Cross-correlation functions (CCFs) were estimated using a 64 beat wide moving window. Mean CCF patterns were obtained for each subject and for the entire population. The MABP and MCBFV signals were bandpass filtered in the very low-frequency range (VLF, 0.015– 0.07 Hz ), low-frequency range (LF, 0.07– 0.15 Hz ) and high-frequency range (HF, 0.15– 0.40 Hz ) before applying CCF for the purpose of studying the effect of different bandwidths on the resulting mean CCFs. Results revealed that the corresponding time lags of the peak values of the MABP–MCBFV CCFs increased significantly between the LF and HF frequency ranges (LF: −1.20±0.91 s , HF: −0.07±0.42 s , p ; paired sign test). The left-shift (negative lag) of the CCF peak between MABP and MCBFV is a result of the phase-lead property. The increasing time lag of the CCF peak indicated evidence of the autoregulatory disturbance. The CCF of pre-filtered spontaneous MABP and MCBFV could be a useful tool to estimate the CA dynamic response.