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1.
J Biomed Opt ; 29(Suppl 3): S33302, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38707651

RESUMO

Significance: Cerebral oximeters have the potential to detect abnormal cerebral blood oxygenation to allow for early intervention. However, current commercial systems have two major limitations: (1) spatial coverage of only the frontal region, assuming that surgery-related hemodynamic effects are global and (2) susceptibility to extracerebral signal contamination inherent to continuous-wave near-infrared spectroscopy (NIRS). Aim: This work aimed to assess the feasibility of a high-density, time-resolved (tr) NIRS device (Kernel Flow) to monitor regional oxygenation changes across the cerebral cortex during surgery. Approach: The Flow system was assessed using two protocols. First, digital carotid compression was applied to healthy volunteers to cause a rapid oxygenation decrease across the ipsilateral hemisphere without affecting the contralateral side. Next, the system was used on patients undergoing shoulder surgery to provide continuous monitoring of cerebral oxygenation. In both protocols, the improved depth sensitivity of trNIRS was investigated by applying moment analysis. A dynamic wavelet filtering approach was also developed to remove observed temperature-induced signal drifts. Results: In the first protocol (28±5 years; five females, five males), hair significantly impacted regional sensitivity; however, the enhanced depth sensitivity of trNIRS was able to separate brain and scalp responses in the frontal region. Regional sensitivity was improved in the clinical study given the age-related reduction in hair density of the patients (65±15 years; 14 females, 13 males). In five patients who received phenylephrine to treat hypotension, different scalp and brain oxygenation responses were apparent, although no regional differences were observed. Conclusions: The Kernel Flow has promise as an intraoperative neuromonitoring device. Although regional sensitivity was affected by hair color and density, enhanced depth sensitivity of trNIRS was able to resolve differences in scalp and brain oxygenation responses in both protocols.


Assuntos
Circulação Cerebrovascular , Espectroscopia de Luz Próxima ao Infravermelho , Humanos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Espectroscopia de Luz Próxima ao Infravermelho/instrumentação , Feminino , Masculino , Adulto , Circulação Cerebrovascular/fisiologia , Hemodinâmica/fisiologia , Oximetria/métodos , Oximetria/instrumentação , Oxigênio/sangue , Oxigênio/metabolismo , Encéfalo/diagnóstico por imagem , Encéfalo/irrigação sanguínea , Desenho de Equipamento
4.
Crit Care Explor ; 6(5): e1083, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38694846

RESUMO

OBJECTIVES: This prospective cohort study aimed to investigate changes in intracranial pressure (ICP) and cerebral hemodynamics in infants with congenital heart disease undergoing the Glenn procedure, focusing on the relationship between superior vena cava pressure and estimated ICP. DESIGN: A single-center prospective cohort study. SETTING: The study was conducted in a cardiac center over 4 years (2019-2022). PATIENTS: Twenty-seven infants with congenital heart disease scheduled for the Glenn procedure were included in the study, and detailed patient demographics and primary diagnoses were recorded. INTERVENTIONS: Transcranial Doppler (TCD) ultrasound examinations were performed at three time points: baseline (preoperatively), postoperative while ventilated (within 24-48 hr), and at discharge. TCD parameters, blood pressure, and pulmonary artery pressure were measured. MEASUREMENTS AND MAIN RESULTS: TCD parameters included systolic flow velocity, diastolic flow velocity (dFV), mean flow velocity (mFV), pulsatility index (PI), and resistance index. Estimated ICP and cerebral perfusion pressure (CPP) were calculated using established formulas. There was a significant postoperative increase in estimated ICP from 11 mm Hg (interquartile range [IQR], 10-16 mm Hg) to 15 mm Hg (IQR, 12-21 mm Hg) postoperatively (p = 0.002) with a trend toward higher CPP from 22 mm Hg (IQR, 14-30 mm Hg) to 28 mm Hg (IQR, 22-38 mm Hg) postoperatively (p = 0.1). TCD indices reflected alterations in cerebral hemodynamics, including decreased dFV and mFV and increased PI. Intracranial hemodynamics while on positive airway pressure and after extubation were similar. CONCLUSIONS: Glenn procedure substantially increases estimated ICP while showing a trend toward higher CPP. These findings underscore the intricate interaction between venous pressure and cerebral hemodynamics in infants undergoing the Glenn procedure. They also highlight the remarkable complexity of cerebrovascular autoregulation in maintaining stable brain perfusion under these circumstances.


Assuntos
Circulação Cerebrovascular , Cardiopatias Congênitas , Hemodinâmica , Pressão Intracraniana , Ultrassonografia Doppler Transcraniana , Humanos , Lactente , Estudos Prospectivos , Feminino , Masculino , Pressão Intracraniana/fisiologia , Cardiopatias Congênitas/cirurgia , Cardiopatias Congênitas/fisiopatologia , Cardiopatias Congênitas/diagnóstico por imagem , Circulação Cerebrovascular/fisiologia , Ultrassonografia Doppler Transcraniana/métodos , Hemodinâmica/fisiologia , Estudos de Coortes , Técnica de Fontan , Veia Cava Superior/fisiopatologia , Veia Cava Superior/diagnóstico por imagem
5.
Andes Pediatr ; 95(2): 202-212, 2024 Apr.
Artigo em Espanhol | MEDLINE | ID: mdl-38801369

RESUMO

Sepsis is one of the main causes of admission to Intensive Care Units (ICU). The hemodynamic objectives usually sought during the resuscitation of the patient in septic shock correspond to macrohemodynamic parameters (heart rate, blood pressure, central venous pressure). However, persistent alterations in microcirculation, despite the restoration of macrohemodynamic parameters, can cause organ failure. This dissociation between the macrocirculation and microcirculation originates the need to evaluate organ tissue perfusion, the most commonly used being urinary output, lactatemia, central venous oxygen saturation (ScvO2), and veno-arterial pCO2 gap. Because peripheral tissues, such as the skin, are sensitive to disturbances in perfusion, noninvasive monitoring of peripheral circulation, such as skin temperature gradient, capillary refill time, mottling score, and peripheral perfusion index may be helpful as early markers of the existence of systemic hemodynamic alterations. Peripheral circulation monitoring techniques are relatively easy to interpret and can be used directly at the patient's bedside. This approach can be quickly applied in the intra- or extra-ICU setting. The objective of this narrative review is to analyze the various existing tissue perfusion markers and to update the evidence that allows guiding hemodynamic support in a more individualized therapy for each patient.


Assuntos
Hemodinâmica , Microcirculação , Humanos , Criança , Microcirculação/fisiologia , Hemodinâmica/fisiologia , Choque Séptico/terapia , Choque Séptico/fisiopatologia , Choque Séptico/diagnóstico , Monitorização Fisiológica/métodos , Monitorização Hemodinâmica/métodos , Doença Aguda , Sepse/diagnóstico , Sepse/terapia , Sepse/fisiopatologia , Biomarcadores/sangue
6.
Khirurgiia (Mosk) ; (5): 95-100, 2024.
Artigo em Russo | MEDLINE | ID: mdl-38785244

RESUMO

A personalized approach with attention to anamnesis and specific symptoms is necessary in patients with internal carotid artery tortuosity. Neuroimaging (especially before elective surgery) or functional stress tests following ultrasound of supra-aortic vessels may be necessary depending on medical history and complaints. In addition to standard Doppler ultrasound, these patients should undergo rotational and orthostatic transformation tests. We analyze changes in shape and hemodynamic parameters within the tortuosity area in various body positions. This is especially valuable for patients with concomitant carotid artery stenosis. The article presents a clinical case illustrating the importance of such approach.


Assuntos
Artéria Carótida Interna , Estenose das Carótidas , Humanos , Artéria Carótida Interna/diagnóstico por imagem , Artéria Carótida Interna/anormalidades , Artéria Carótida Interna/fisiopatologia , Estenose das Carótidas/fisiopatologia , Estenose das Carótidas/complicações , Estenose das Carótidas/diagnóstico , Estenose das Carótidas/cirurgia , Masculino , Feminino , Pessoa de Meia-Idade , Ultrassonografia Doppler/métodos , Hemodinâmica/fisiologia , Aterosclerose/complicações , Aterosclerose/diagnóstico , Aterosclerose/fisiopatologia , Malformações Vasculares/diagnóstico , Malformações Vasculares/complicações , Malformações Vasculares/fisiopatologia , Idoso , Artérias/anormalidades , Instabilidade Articular , Dermatopatias Genéticas
7.
Sci Rep ; 14(1): 11649, 2024 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-38773192

RESUMO

Recent research has revealed that hemodynamic changes caused by lung recruitment maneuvers (LRM) with continuous positive airway pressure can be used to identify fluid responders. We investigated the usefulness of stepwise LRM with increasing positive end-expiratory pressure and constant driving pressure for predicting fluid responsiveness in patients under lung protective ventilation (LPV). Forty-one patients under LPV were enrolled when PPV values were in a priori considered gray zone (4% to 17%). The FloTrac-Vigileo device measured stroke volume variation (SVV) and stroke volume (SV), while the patient monitor measured pulse pressure variation (PPV) before and at the end of stepwise LRM and before and 5 min after fluid challenge (6 ml/kg). Fluid responsiveness was defined as a ≥ 15% increase in the SV or SV index. Seventeen were fluid responders. The areas under the curve for the augmented values of PPV and SVV, as well as the decrease in SV by stepwise LRM to identify fluid responders, were 0.76 (95% confidence interval, 0.61-0.88), 0.78 (0.62-0.89), and 0.69 (0.53-0.82), respectively. The optimal cut-offs for the augmented values of PPV and SVV were > 18% and > 13%, respectively. Stepwise LRM -generated augmented PPV and SVV predicted fluid responsiveness under LPV.


Assuntos
Hidratação , Salas Cirúrgicas , Humanos , Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Hidratação/métodos , Respiração com Pressão Positiva/métodos , Respiração Artificial/métodos , Pulmão/fisiologia , Pulmão/fisiopatologia , Volume Sistólico/fisiologia , Hemodinâmica/fisiologia
8.
Curr Probl Cardiol ; 49(7): 102619, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38723794

RESUMO

OBJECTIVE: This systematic review aims to assess the comparative effectiveness and safety of temporary mechanical circulatory support (MCS) devices in various subgroups of patients with acute cardiogenic shock, providing insights for personalized clinical decision-making. METHODS: We conducted a comprehensive search across major databases to identify studies that reported on the use of temporary MCS devices like TandemHeart, Impella, and VA-ECMO in acute cardiogenic shock. Special attention was given to subgroup analyses based on etiologies of shock, patient demographics, and comorbid conditions. RESULTS: Our analysis revealed that while devices like TandemHeart and Impella offer significant hemodynamic support, their effectiveness and safety profiles vary across different patient subgroups. VA-ECMO demonstrated the highest flow rates and potential for mortality benefits but requires careful management due to associated risks. The lack of randomized controlled trials in specific patient subgroups highlights a gap in the current literature, underscoring the need for targeted research. CONCLUSION: The review underscores the necessity of a personalized approach in selecting temporary MCS devices for patients with acute cardiogenic shock, guided by specific patient characteristics and clinical scenarios. Future research should focus on addressing the identified evidence gaps through well-designed studies that provide robust subgroup-specific data, enabling clinicians to optimize treatment strategies and improve patient outcomes in this critical care context.


Assuntos
Oxigenação por Membrana Extracorpórea , Coração Auxiliar , Choque Cardiogênico , Choque Cardiogênico/terapia , Choque Cardiogênico/mortalidade , Humanos , Coração Auxiliar/efeitos adversos , Oxigenação por Membrana Extracorpórea/métodos , Oxigenação por Membrana Extracorpórea/efeitos adversos , Resultado do Tratamento , Doença Aguda , Hemodinâmica/fisiologia
9.
Sensors (Basel) ; 24(9)2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38733027

RESUMO

Heart failure (HF) is a complex clinical syndrome associated with significant morbidity, mortality, and healthcare costs. It is characterized by various structural and/or functional abnormalities of the heart, resulting in elevated intracardiac pressure and/or inadequate cardiac output at rest and/or during exercise. These dysfunctions can originate from a variety of conditions, including coronary artery disease, hypertension, cardiomyopathies, heart valve disorders, arrhythmias, and other lifestyle or systemic factors. Identifying the underlying cause is crucial for detecting reversible or treatable forms of HF. Recent epidemiological studies indicate that there has not been an increase in the incidence of the disease. Instead, patients seem to experience a chronic trajectory marked by frequent hospitalizations and stagnant mortality rates. Managing these patients requires a multidisciplinary approach that focuses on preventing disease progression, controlling symptoms, and preventing acute decompensations. In the outpatient setting, patient self-care plays a vital role in achieving these goals. This involves implementing necessary lifestyle changes and promptly recognizing symptoms/signs such as dyspnea, lower limb edema, or unexpected weight gain over a few days, to alert the healthcare team for evaluation of medication adjustments. Traditional methods of HF monitoring, such as symptom assessment and periodic clinic visits, may not capture subtle changes in hemodynamics. Sensor-based technologies offer a promising solution for remote monitoring of HF patients, enabling early detection of fluid overload and optimization of medical therapy. In this review, we provide an overview of the CardioMEMS device, a novel sensor-based system for pulmonary artery pressure monitoring in HF patients. We discuss the technical aspects, clinical evidence, and future directions of CardioMEMS in HF management.


Assuntos
Insuficiência Cardíaca , Humanos , Insuficiência Cardíaca/terapia , Insuficiência Cardíaca/fisiopatologia , Cardiologia/métodos , Monitorização Fisiológica/métodos , Monitorização Fisiológica/instrumentação , Gerenciamento Clínico , Hemodinâmica/fisiologia
10.
Eur J Cardiothorac Surg ; 65(5)2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38710669

RESUMO

OBJECTIVES: The objective of this analysis was to assess the normal haemodynamic performance of contemporary surgical aortic valves at 1 year postimplant in patients undergoing surgical aortic valve replacement for significant valvular dysfunction. By pooling data from 4 multicentre studies, this study will contribute to a better understanding of the effectiveness of surgical aortic valve replacement procedures, aiding clinicians and researchers in making informed decisions regarding valve selection and patient management. METHODS: Echocardiograms were assessed by a single core laboratory. Effective orifice area, dimensionless velocity index, mean aortic gradient, peak aortic velocity and stroke volume were evaluated. RESULTS: The cohort included 2958 patients. Baseline age in the studies ranged from 70.1 ± 9.0 to 83.3 ± 6.4 years, and Society of Thoracic Surgeons risk of mortality was 1.9 ± 0.7 to 7.5 ± 3.4%. Twenty patients who had received a valve model implanted in fewer than 10 cases were excluded. Ten valve models (all tissue valves; n = 2938 patients) were analysed. At 1 year, population mean effective orifice area ranged from 1.46 ± 0.34 to 2.12 ± 0.59 cm2, and dimensionless velocity index, from 0.39 ± 0.07 to 0.56 ± 0.15. The mean gradient ranged from 8.6 ± 3.4 to 16.1 ± 6.2 mmHg with peak aortic velocity of 1.96 ± 0.39 to 2.65 ± 0.47 m/s. Stroke volume was 75.3 ± 19.6 to 89.8 ± 24.3 ml. CONCLUSIONS: This pooled cohort is the largest to date of contemporary surgical aortic valves with echocardiograms analysed by a single core lab. Overall haemodynamic performance at 1 year ranged from good to excellent. These data can serve as a benchmark for other studies and may be useful to evaluate the performance of bioprosthetic surgical valves over time. CLINICAL TRIAL REGISTRATION NUMBER: NCT02088554, NCT02701283, NCT01586910 and NCT01531374.


Assuntos
Valva Aórtica , Bioprótese , Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas , Hemodinâmica , Humanos , Hemodinâmica/fisiologia , Valva Aórtica/cirurgia , Valva Aórtica/diagnóstico por imagem , Idoso , Feminino , Masculino , Idoso de 80 Anos ou mais , Implante de Prótese de Valva Cardíaca/métodos , Ecocardiografia , Pessoa de Meia-Idade , Desenho de Prótese
11.
J Biomech ; 168: 112124, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38701696

RESUMO

Congenital arterial stenosis such as supravalvar aortic stenosis (SVAS) are highly prevalent in Williams syndrome (WS) and other arteriopathies pose a substantial health risk. Conventional tools for severity assessment, including clinical findings and pressure gradient estimations, often fall short due to their susceptibility to transient physiological changes and disease stage influences. Moreover, in the pediatric population, the severity of these and other congenital heart defects (CHDs) often restricts the applicability of invasive techniques for obtaining crucial physiological data. Conversely, evaluating CHDs and their progression requires a comprehensive understanding of intracardiac blood flow. Current imaging modalities, such as blood speckle imaging (BSI) and four-dimensional magnetic resonance imaging (4D MRI) face limitations in resolving flow data, especially in cases of elevated flow velocities. To address these challenges, we devised a computational framework employing zero-dimensional (0D) lumped parameter models coupled with patient-specific reconstructed geometries pre- and post-surgical intervention to execute computational fluid dynamic (CFD) simulations. This framework facilitates the analysis and visualization of intricate blood flow patterns, offering insights into geometry and flow dynamics alterations impacting cardiac function. In this study, we aim to assess the efficacy of surgical intervention in correcting an extreme aortic defect in a patient with WS, leading to reductions in wall shear stress (WSS), maximum velocity magnitude, pressure drop, and ultimately a decrease in cardiac workload.


Assuntos
Hemodinâmica , Modelos Cardiovasculares , Síndrome de Williams , Humanos , Síndrome de Williams/fisiopatologia , Síndrome de Williams/diagnóstico por imagem , Hemodinâmica/fisiologia , Cardiopatias Congênitas/fisiopatologia , Cardiopatias Congênitas/complicações , Cardiopatias Congênitas/diagnóstico por imagem , Aorta/fisiopatologia , Aorta/diagnóstico por imagem , Velocidade do Fluxo Sanguíneo/fisiologia , Masculino , Feminino , Simulação por Computador
12.
Sci Rep ; 14(1): 10242, 2024 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-38702415

RESUMO

Cerebral infra-slow oscillation (ISO) is a source of vasomotion in endogenic (E; 0.005-0.02 Hz), neurogenic (N; 0.02-0.04 Hz), and myogenic (M; 0.04-0.2 Hz) frequency bands. In this study, we quantified changes in prefrontal concentrations of oxygenated hemoglobin (Δ[HbO]) and redox-state cytochrome c oxidase (Δ[CCO]) as hemodynamic and metabolic activity metrics, and electroencephalogram (EEG) powers as electrophysiological activity, using concurrent measurements of 2-channel broadband near-infrared spectroscopy and EEG on the forehead of 22 healthy participants at rest. After preprocessing, the multi-modality signals were analyzed using generalized partial directed coherence to construct unilateral neurophysiological networks among the three neurophysiological metrics (with simplified symbols of HbO, CCO, and EEG) in each E/N/M frequency band. The links in these networks represent neurovascular, neurometabolic, and metabolicvascular coupling (NVC, NMC, and MVC). The results illustrate that the demand for oxygen by neuronal activity and metabolism (EEG and CCO) drives the hemodynamic supply (HbO) in all E/N/M bands in the resting prefrontal cortex. Furthermore, to investigate the effect of transcranial photobiomodulation (tPBM), we performed a sham-controlled study by delivering an 800-nm laser beam to the left and right prefrontal cortex of the same participants. After performing the same data processing and statistical analysis, we obtained novel and important findings: tPBM delivered on either side of the prefrontal cortex triggered the alteration or reversal of directed network couplings among the three neurophysiological entities (i.e., HbO, CCO, and EEG frequency-specific powers) in the physiological network in the E and N bands, demonstrating that during the post-tPBM period, both metabolism and hemodynamic supply drive electrophysiological activity in directed network coupling of the prefrontal cortex (PFC). Overall, this study revealed that tPBM facilitates significant modulation of the directionality of neurophysiological networks in electrophysiological, metabolic, and hemodynamic activities.


Assuntos
Eletroencefalografia , Córtex Pré-Frontal , Espectroscopia de Luz Próxima ao Infravermelho , Humanos , Córtex Pré-Frontal/fisiologia , Córtex Pré-Frontal/metabolismo , Masculino , Adulto , Feminino , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Terapia com Luz de Baixa Intensidade/métodos , Adulto Jovem , Descanso/fisiologia , Oxiemoglobinas/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Hemodinâmica/fisiologia , Rede Nervosa/fisiologia , Rede Nervosa/metabolismo
13.
PLoS One ; 19(5): e0302828, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38722930

RESUMO

Cupping therapy is a popular intervention for improving muscle recovery after exercise although clinical evidence is weak. Previous studies demonstrated that cupping therapy may improve microcirculation of the soft tissue to accelerate tissue healing. However, it is unclear whether the cupping size could affect the spatial hemodynamic response of the treated muscle. The objective of this study was to use 8-channel near-infrared spectroscopy to assess this clinical question by assessing the effect of 3 cupping sizes (35, 40, and 45 mm in inner diameter of the circular cup) under -300 mmHg for 5 min on the muscle hemodynamic response from the area inside and outside the cup, including oxyhemoglobin and deoxy-hemoglobin in 18 healthy adults. Two-way factorial design was used to assess the interaction between the cupping size (35, 40, and 45 mm) and the location (inside and outside the cup) and the main effects of the cupping size and the location. The two-way repeated measures ANOVA demonstrated an interaction between the cupping size and the location in deoxy-hemoglobin (P = 0.039) but no interaction in oxyhemoglobin (P = 0.100), and a main effect of the cup size (P = 0.001) and location (P = 0.023) factors in oxyhemoglobin. For the cupping size factor, the 45-mm cup resulted in a significant increase in oxyhemoglobin (5.738±0.760 µM) compared to the 40-mm (2.095±0.312 µM, P<0.001) and 35-mm (3.134±0.515 µM, P<0.01) cup. Our findings demonstrate that the cupping size and location factors affect the muscle hemodynamic response, and the use of multi-channel near-infrared spectroscopy may help understand benefits of cupping therapy on managing musculoskeletal impairment.


Assuntos
Hemodinâmica , Músculo Esquelético , Oxiemoglobinas , Espectroscopia de Luz Próxima ao Infravermelho , Humanos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Masculino , Hemodinâmica/fisiologia , Feminino , Adulto , Músculo Esquelético/fisiologia , Músculo Esquelético/irrigação sanguínea , Oxiemoglobinas/metabolismo , Oxiemoglobinas/análise , Ventosaterapia/métodos , Adulto Jovem , Hemoglobinas/metabolismo
14.
Sci Rep ; 14(1): 11287, 2024 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-38760449

RESUMO

Spectrum power analysis in the low frequency oscillations (LFO) region of functional near infrared spectroscopy (fNIRS) is a promising method to deliver information about brain activation and therefore might be used for prognostication in patients with disorders of consciousness in the neurocritical care unit alongside with established methods. In this study, we measure the cortical hemodynamic response measured by fNIRS in the LFO region following auditory and somatosensory stimulation in healthy subjects. The significant hemodynamic reaction in the contralateral hemisphere correlation with the physiologic electric response suggests neurovascular coupling. In addition, we investigate power spectrum changes in steady state measurements of cerebral death patients and healthy subjects in the LFO region, the frequency of the heartbeat and respiration. The spectral power within the LFO region was lower in the patients with cerebral death compared to the healthy subjects, whereas there were no differences in spectral power for physiological activities such as heartbeat and respiration rate. This finding indicates the cerebral origin of our low frequency measurements. Therefore, LFO measurements are a potential method to detect brain activation in patients with disorders of consciousness and cerebral death. However, further studies in patients are needed to investigate its potential clinical use.


Assuntos
Morte Encefálica , Acoplamento Neurovascular , Espectroscopia de Luz Próxima ao Infravermelho , Humanos , Masculino , Feminino , Adulto , Acoplamento Neurovascular/fisiologia , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Morte Encefálica/fisiopatologia , Pessoa de Meia-Idade , Hemodinâmica/fisiologia , Idoso , Encéfalo/fisiopatologia , Encéfalo/fisiologia , Encéfalo/diagnóstico por imagem , Frequência Cardíaca/fisiologia
15.
Sensors (Basel) ; 24(10)2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38794026

RESUMO

Participant movement is a major source of artifacts in functional near-infrared spectroscopy (fNIRS) experiments. Mitigating the impact of motion artifacts (MAs) is crucial to estimate brain activity robustly. Here, we suggest and evaluate a novel application of the nonlinear Hammerstein-Wiener model to estimate and mitigate MAs in fNIRS signals from direct-movement recordings through IMU sensors mounted on the participant's head (head-IMU) and the fNIRS probe (probe-IMU). To this end, we analyzed the hemodynamic responses of single-channel oxyhemoglobin (HbO) and deoxyhemoglobin (HbR) signals from 17 participants who performed a hand tapping task with different levels of concurrent head movement. Additionally, the tapping task was performed without head movements to estimate the ground-truth brain activation. We compared the performance of our novel approach with the probe-IMU and head-IMU to eight established methods (PCA, tPCA, spline, spline Savitzky-Golay, wavelet, CBSI, RLOESS, and WCBSI) on four quality metrics: SNR, △AUC, RMSE, and R. Our proposed nonlinear Hammerstein-Wiener method achieved the best SNR increase (p < 0.001) among all methods. Visual inspection revealed that our approach mitigated MA contaminations that other techniques could not remove effectively. MA correction quality was comparable with head- and probe-IMUs.


Assuntos
Artefatos , Espectroscopia de Luz Próxima ao Infravermelho , Humanos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Masculino , Adulto , Feminino , Movimento/fisiologia , Movimento (Física) , Oxiemoglobinas/análise , Encéfalo/fisiologia , Adulto Jovem , Hemoglobinas/análise , Algoritmos , Processamento de Sinais Assistido por Computador , Hemodinâmica/fisiologia
16.
Aerosp Med Hum Perform ; 95(6): 297-304, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38790119

RESUMO

INTRODUCTION: Negative pressure breathing is breathing with decreased pressure in the respiratory tract without lowering pressure acting on the torso. We lowered air pressure only during inspiration (NPBin). NPBin, used to increase venous return to the heart, is considered a countermeasure against redistribution of body fluids toward the head during spaceflight. We studied NPBin effects on circulation in healthy humans with an emphasis on NPBin-induced oscillations of hemodynamic parameters synchronous with breathing. We propose an approach to analyze the oscillations based on coherent averaging.METHODS: Eight men ages 24-42 yr participated in the NPBin and control series. During the series, to reproduce fluids shift observed under microgravity, subjects were supine and head down (-8°). Duration of NPBin was 20 min, rarefaction -20 cm H2O. Hemodynamic parameters were measured by Finometer. Electrical impedance measurements were used to estimate changes in blood filling of cerebral vessels.RESULTS: Mean values of hemodynamic parameters virtually did not change under NPBin, but NPBin induced oscillations of the parameters synchronous with respiration. Peak-to-peak amplitude under NPBin were: mean arterial pressure, 4 ± 1 (mmHg); stroke volume, 7 ± 3 (mL); and heart rate, 4 ± 1 (bpm). Electrical impedance of the head increased during inspiration. The increase under NPBin was three times greater than under normal breathing.DISCUSSION: Analysis of oscillations gives more information than analysis of mean values. NPBin induces short-term decrease in left ventricle stroke volume and arterial blood pressure during each inspiration; the decrease is compensated by increase after inspiration. NPBin facilitates redistribution of body fluids away from the head.Semenov YS, Melnikov IS, Luzhnov PV, Dyachenko AI. Oscillations of hemodynamic parameters induced by negative pressure breathing in healthy humans. Aerosp Med Hum Perform. 2024; 95(6):297-304.


Assuntos
Hemodinâmica , Humanos , Masculino , Adulto , Hemodinâmica/fisiologia , Adulto Jovem , Frequência Cardíaca/fisiologia , Volume Sistólico/fisiologia , Deslocamentos de Líquidos Corporais/fisiologia , Ausência de Peso , Voluntários Saudáveis , Respiração , Decúbito Inclinado com Rebaixamento da Cabeça/fisiologia , Inalação/fisiologia
17.
Physiol Behav ; 281: 114574, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38697274

RESUMO

Postural change from supine or sitting to standing up leads to displacement of 300 to 1000 mL of blood from the central parts of the body to the lower limb, which causes a decrease in venous return to the heart, hence decrease in cardiac output, causing a drop in blood pressure. This may lead to falling down, syncope, and in general reducing the quality of daily activities, especially in the elderly and anyone suffering from nervous system disorders such as Parkinson's or orthostatic hypotension (OH). Among different modalities to study brain function, functional near-infrared spectroscopy (fNIRS) is a neuroimaging method that optically measures the hemodynamic response in brain tissue. Concentration changes in oxygenated hemoglobin (HbO2) and deoxygenated hemoglobin (HHb) are associated with brain neural activity. fNIRS is significantly more tolerant to motion artifacts compared to fMRI, PET, and EEG. At the same time, it is portable, has a simple structure and usage, is safer, and much more economical. In this article, we systematically reviewed the literature to examine the history of using fNIRS in monitoring brain oxygenation changes caused by sudden changes in body position and its relationship with the blood pressure changes. First, the theory behind brain hemodynamics monitoring using fNIRS and its advantages and disadvantages are presented. Then, a study of blood pressure variations as a result of postural changes using fNIRS is described. It is observed that only 58 % of the references concluded a positive correlation between brain oxygenation changes and blood pressure changes. At the same time, 3 % showed a negative correlation, and 39 % did not show any correlation between them.


Assuntos
Pressão Sanguínea , Encéfalo , Hemodinâmica , Postura , Espectroscopia de Luz Próxima ao Infravermelho , Humanos , Encéfalo/diagnóstico por imagem , Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Pressão Sanguínea/fisiologia , Postura/fisiologia , Hemodinâmica/fisiologia
18.
J Cardiothorac Surg ; 19(1): 284, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38730503

RESUMO

INTRODUCTION: Post liver transplantation (LT) patients endure high morbidity rate of multi-organ ischemic symptoms following reperfusion. We hypothesize that enhanced external counterpulsation (EECP) as a typical non-invasive assisted circulation procedure, which can efficiently inhibit the relative ischemic symptoms via the systemic improvement of hemodynamics. CASE PRESENTATION: A 51-year-old male patient, 76 kg, 172 cm, received orthotopic LT surgery for viral hepatitis B induced acute-on-chronic liver failure hepatic failure. His medical records revealed ischemic symptoms in multi-organ at the time of hospital discharge, including headache, refractory insomnia, abdominal paralysis, and lower limb pain. The EECP treatment was introduced for assisted rehabilitation and to improve the postoperative quality of life. Doppler Ultrasound examination showed significant augmentation of blood flow volume in the carotid arteries, the hepatic artery, the portal vein and the femoral artery during EECP intervention. A standard 35-hour EECP treatment led to significant improvement in quality of life, e.g. sleep quality and walking ability. CONCLUSION: We report a case of multi-organ ischemic symptoms in a post LT patient. EECP treatment can significantly improve the quality of life via the systematic promotion of hemodynamics.


Assuntos
Contrapulsação , Hemodinâmica , Transplante de Fígado , Humanos , Masculino , Pessoa de Meia-Idade , Contrapulsação/métodos , Hemodinâmica/fisiologia , Complicações Pós-Operatórias/terapia , Qualidade de Vida , Isquemia/cirurgia , Isquemia/fisiopatologia
20.
J Neural Eng ; 21(2)2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38621377

RESUMO

Objective.Dopaminergic treatment is effective for Parkinson's disease (PD). Nevertheless, the conventional treatment assessment mainly focuses on human-administered behavior examination while the underlying functional improvements have not been well explored. This paper aims to investigate brain functional variations of PD patients after dopaminergic therapy.Approach.This paper proposed a dynamic brain network decomposition method and discovered brain hemodynamic sub-networks that well characterized the efficacy of dopaminergic treatment in PD. Firstly, a clinical walking procedure with functional near-infrared spectroscopy was developed, and brain activations during the procedure from fifty PD patients under the OFF and ON states (without and with dopaminergic medication) were captured. Then, dynamic brain networks were constructed with sliding-window analysis of phase lag index and integrated time-varying functional networks across all patients. Afterwards, an aggregated network decomposition algorithm was formulated based on aggregated effectiveness optimization of functional networks in spanning network topology and cross-validation network variations, and utilized to unveil effective brain hemodynamic sub-networks for PD patients. Further, dynamic sub-network features were constructed to characterize the brain flexibility and dynamics according to the temporal switching and activation variations of discovered sub-networks, and their correlations with differential treatment-induced gait alterations were analyzed.Results.The results demonstrated that PD patients exhibited significantly enhanced flexibility after dopaminergic therapy within a sub-network related to the improvement of motor functions. Other sub-networks were significantly correlated with trunk-related axial symptoms and exhibited no significant treatment-induced dynamic interactions.Significance.The proposed method promises a quantified and objective approach for dopaminergic treatment evaluation. Moreover, the findings suggest that the gait of PD patients comprises distinct motor domains, and the corresponding neural controls are selectively responsive to dopaminergic treatment.


Assuntos
Encéfalo , Doença de Parkinson , Humanos , Doença de Parkinson/fisiopatologia , Doença de Parkinson/tratamento farmacológico , Masculino , Feminino , Encéfalo/fisiopatologia , Pessoa de Meia-Idade , Idoso , Hemodinâmica/fisiologia , Hemodinâmica/efeitos dos fármacos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Rede Nervosa/fisiopatologia , Rede Nervosa/efeitos dos fármacos , Dopaminérgicos/administração & dosagem , Caminhada/fisiologia
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