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2.
PLoS One ; 15(1): e0227145, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31899768

RESUMO

Measurement of cardiac function is vital for the health of pediatric patients with heart disease. Standard tools to measure function including echocardiogram and magnetic residence imaging are time intensive, costly, and have limited accessibility. The Vivio is a novel, non-invasive, handheld device that screens for cardiac dysfunction by analyzing intrinsic frequencies (IF) ω1 and ω2 of carotid artery waveforms. Prior studies demonstrated that left ventricular ejection fraction can be derived from IFs in adults. This study 1) studies whether the Vivio can capture carotid arterial pulse waveform data in children ages 0-19 years old; 2) tests the performance of two sensor head geometries, one larger and smaller than the standard size used in adults, designed for the pediatric population; 3) compares the IFs between pediatric age groups and adults with normal function. The Vivio successfully measured a carotid artery waveform in all children over 5 years old and 28% of children under the age of five. The small head did not accurately measure a waveform in any age group. One-way analysis of variance (ANOVA) demonstrated a difference in the IF ω1 between the adult and pediatric cohorts (F = 7.3, Prob>F = 0.0001). Post host analysis demonstrated a difference between the adult cohort (ω1 = 99 +/- 5 bpm) and the cohorts ages 0-4 (ω1 = 111 +/- 2 bpm; p = 0.0006) and 15-19 years old (ω1 = 105 +/-5 bpm; p = 0.02). One-way ANOVA demonstrated a difference in the IF ω2 between the adult and pediatric cohorts (F = 4.8, Prob>F = 0.003), specifically between the adult (ω2 = 81 +/- 13 bpm) and age 0-4 cohorts (ω2 = 48 +/- 8 bpm; p = 0.002). These results suggest that the Vivio can be used to capture carotid pulse waveform data in pediatric populations and that the data produced can be used to measure intrinsic frequencies.


Assuntos
Determinação da Frequência Cardíaca/instrumentação , Monitorização Hemodinâmica/instrumentação , Estudo de Prova de Conceito , Volume Sistólico/fisiologia , Função Ventricular Esquerda/fisiologia , Tecnologia sem Fio/instrumentação , Adolescente , Adulto , Artérias Carótidas/fisiologia , Cefalometria , Criança , Pré-Escolar , Estudos de Coortes , Estudos de Viabilidade , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Pulso Arterial , Adulto Jovem
3.
Int J Sports Med ; 41(2): 69-74, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31791087

RESUMO

Oxygen uptake (V̇O2), heart rate (HR), energy cost (EC) and oxygen pulse are lower during downhill compared to level or uphill locomotion. However, a change in oxygen pulse and EC during prolonged grade exercise is not well documented. This study investigated changes in cardiorespiratory responses and EC during 45-min grade exercises. Nine male healthy volunteers randomly ran at 75% HR reserve during 45-min exercise in a level (+1%), uphill (+15%) or downhill (-15%) condition. V̇O2 , minute ventilation (V̇E ) and end-tidal carbon dioxide (PetCO2) were recorded continuously with 5-min averaging between the 10th and 15th min (T1) and 40th and 45th min (T2). For a similar HR (157±3 bpm), V̇O2 , V̇E , and PetCO2 were lower during downhill compared to level and uphill conditions (p<0.01). V̇O2 and V̇E decreased similarly from T1 to T2 for all conditions (all p<0.01), while PetCO2 decreased only for the downhill condition (p<0.001). Uphill exercise required greater EC compared to level and downhill exercises. EC decreased only during the uphill condition between T1 and T2 (p<0.01). The lowest V̇O2 and EC during downhill exercise compared to uphill and level exercises suggests the involvement of passive elastic structures in force production during downhill. The lower cardiorespiratory response and the reduction in PetCO2 during downhill running exercise, while EC remained constant, suggests an overdrive ventilation pattern likely due to a greater stimulation of efferent neural factors.


Assuntos
Metabolismo Energético/fisiologia , Frequência Cardíaca/fisiologia , Consumo de Oxigênio/fisiologia , Troca Gasosa Pulmonar/fisiologia , Corrida/fisiologia , Adulto , Meio Ambiente , Humanos , Masculino , Pulso Arterial , Adulto Jovem
4.
Am Heart J ; 220: 1-11, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31756389

RESUMO

BACKGROUND: Heart failure (HF) emergence in atrial fibrillation (AF) patients undergoing different treatment strategies has not been studied. METHODS: AFFIRM trial subjects with no history of HF, without clinical HF and normal left ventricular ejection fraction at enrollment were identified. The principal outcome was time to development of a composite of New York Heart Association class ≥II HF and/or cardiovascular (CV) death. It was compared for rate and rhythm strategies and correlated with electrocardiographic parameters on follow-up (FU). RESULTS: A total of 1,771 patients (880 rate, 891 rhythm) were evaluated. The principal outcome occurred in 21.4% of rate and 16.8% of rhythm subjects at 5 years (hazard ratio [HR] 1.32, 95% CI 1.04-1.69, P = .024). HF increment by 2 classes increased total mortality (HR 2.83, 95% CI 1.91-4.18, P < .0001), cardiac mortality, (HR 4.27, 95% CI 2.03-9.04, P = .0001), and CV hospitalizations (HR 3.04, 95% CI 2.15-4.29, P < .0001). HF emergence during FU was associated with AF (P = .0004), ventricular rate >80 beats/min (P = .0106), and higher frequency of recorded AF in the rhythm arm (25%-75% vs <25%, HR 1.69, 95% CI 1.09-2.64, P = .020; >75% vs <25%, HR 3.15, 95% CI 1.87-5.34, P =< .001). CONCLUSIONS: (1) In AF patients without HF, symptomatic HF emergence was more frequent with rate control than with rhythm control. (2) HF appearance presages increased mortality risk. (3) Delaying HF emergence is associated with effective rhythm control with documented sinus rhythm during >75% of FU visits as well as ventricular rate control.


Assuntos
Fibrilação Atrial/complicações , Insuficiência Cardíaca/etiologia , Frequência Cardíaca , Pulso Arterial , Idoso , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/mortalidade , Fibrilação Atrial/fisiopatologia , Causas de Morte , Estudos de Coortes , Eletrocardiografia , Feminino , Seguimentos , Cardiopatias/mortalidade , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/fisiopatologia , Hospitalização , Humanos , Estimativa de Kaplan-Meier , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Fatores de Tempo , Resultado do Tratamento , Função Ventricular Esquerda/fisiologia
5.
PLoS One ; 14(12): e0225950, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31825982

RESUMO

BACKGROUND: There is a large group of patients with ischemia of lower limbs not suitable for surgical reconstruction of arteries treated with the help of external assist by intermittent pneumatic compression devices (IPC). Until recently the generally accepted notion was that by compressing tissues below the knee, veins become emptied, venous pressure drops to zero and the increased arterial-venous pressure gradient enables greater arterial flow. We used a pump that, in contradiction to the "empty veins" devices, limited the limb venous outflow by venous obstructions and in a long period therapy expanded the perfusion vessels and brought about persistent reactive hyperemia. AIM: To check the toe and calf arterial inflow measured by venous stasis plethysmography and capillary flow velocity during arterial assist IPC in a long-term therapy of ischemic legs. MATERIAL AND METHODS: Eighteen patients (12M, 6F) age 62 to 75 with leg peripheral arterial disease (PAD, Fontaine stage II) were studied. Pneumatic device with two 10cm wide cuffs (foot, calf) (Bio Compression Systems, Moonachie, NJ, USA) inflated to 120 mmHg for 5-6 sec to obstruct the venous flow, deflation time 16 sec, applied for 45-60 min daily for a period of 2 years. RESULTS: At pump inflation increase in toe arterial pressure, volume, capillary blood flow velocity and one-minute arterial inflow test was observed. Increased toe volume appeared concomitantly with the inflated chamber venous obstruction. Resting pressure in the great saphenous vein increased. The two years therapy showed persistence of the resting limb increased toe capillary flow. Intermittent claudication distance increased by 20-120%. After two years arterial assist TBI increased from 0.2 to 0.6 (range 0.3 to 0.8) (p<0.05 vs pre-therapy). The toe arterial inflow dominated over that in calf skin and muscles, nevertheless, there was prolongation of the claudication distance presumably due to dilatation of exchange vessels also in muscles. CONCLUSIONS: Our arterial assist IPC brought about increase in the toe capillary flow, long lasting dilatation of toe capillaries and extension of painless walking distance. The crucial factor of rhythmic repeated venous outflow obstructions should be taken into account in designing effective assist devices.


Assuntos
Artérias/fisiopatologia , Dispositivos de Compressão Pneumática Intermitente , Isquemia/fisiopatologia , Isquemia/terapia , Perna (Membro)/irrigação sanguínea , Fluxo Sanguíneo Regional , Veias/fisiopatologia , Velocidade do Fluxo Sanguíneo , Feminino , Humanos , Fluxometria por Laser-Doppler , Masculino , Pletismografia , Pulso Arterial , Meias de Compressão , Fatores de Tempo , Pressão Venosa
6.
BMC Biol ; 17(1): 103, 2019 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-31831016

RESUMO

BACKGROUND: Videographic material of animals can contain inapparent signals, such as color changes or motion that hold information about physiological functions, such as heart and respiration rate, pulse wave velocity, and vocalization. Eulerian video magnification allows the enhancement of such signals to enable their detection. The purpose of this study is to demonstrate how signals relevant to experimental physiology can be extracted from non-contact videographic material of animals. RESULTS: We applied Eulerian video magnification to detect physiological signals in a range of experimental models and in captive and free ranging wildlife. Neotenic Mexican axolotls were studied to demonstrate the extraction of heart rate signal of non-embryonic animals from dedicated videographic material. Heart rate could be acquired both in single and multiple animal setups of leucistic and normally colored animals under different physiological conditions (resting, exercised, or anesthetized) using a wide range of video qualities. Pulse wave velocity could also be measured in the low blood pressure system of the axolotl as well as in the high-pressure system of the human being. Heart rate extraction was also possible from videos of conscious, unconstrained zebrafish and from non-dedicated videographic material of sand lizard and giraffe. This technique also allowed for heart rate detection in embryonic chickens in ovo through the eggshell and in embryonic mice in utero and could be used as a gating signal to acquire two-phase volumetric micro-CT data of the beating embryonic chicken heart. Additionally, Eulerian video magnification was used to demonstrate how vocalization-induced vibrations can be detected in infrasound-producing Asian elephants. CONCLUSIONS: Eulerian video magnification provides a technique to extract inapparent temporal signals from videographic material of animals. This can be applied in experimental and comparative physiology where contact-based recordings (e.g., heart rate) cannot be acquired.


Assuntos
Ambystoma mexicanum/fisiologia , Frequência Cardíaca , Fisiologia/métodos , Gravação de Videoteipe/métodos , Peixe-Zebra/fisiologia , Animais , Embrião de Galinha , Humanos , Camundongos , Pulso Arterial/instrumentação , Análise de Onda de Pulso/instrumentação
7.
PLoS One ; 14(12): e0226671, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31869370

RESUMO

BACKGROUND: Atrial fibrillation (AF) is the most common type of cardiac arrhythmia and is associated with increased risk of stroke and congestive heart failure. Lead-I electrocardiogram (ECG) devices are handheld instruments that can detect AF at a single-time point. PURPOSE: To assess the diagnostic test accuracy, clinical impact and cost effectiveness of single-time point lead-I ECG devices compared with manual pulse palpation (MPP) followed by a 12-lead ECG for the detection of AF in symptomatic primary care patients with an irregular pulse. METHODS: Electronic databases (MEDLINE, MEDLINE Epub Ahead of Print and MEDLINE In-Process, EMBASE, PubMed and Cochrane Databases of Systematic Reviews, Cochrane Central Database of Controlled Trials, Database of Abstracts of Reviews of Effects, Health Technology Assessment Database) were searched to March 2018. Two reviewers screened the search results, extracted data and assessed study quality. Summary estimates of diagnostic accuracy were calculated using bivariate models. Cost-effectiveness was evaluated using an economic model consisting of a decision tree and two cohort Markov models. RESULTS: Diagnostic accuracy The diagnostic accuracy (13 publications reporting on nine studies) and clinical impact (24 publications reporting on 19 studies) results are derived from an asymptomatic population (used as a proxy for people with signs or symptoms of AF). The summary sensitivity of lead-I ECG devices was 93.9% (95% confidence interval [CI]: 86.2% to 97.4%) and summary specificity was 96.5% (95% CI: 90.4% to 98.8%). Cost effectiveness The de novo economic model yielded incremental cost effectiveness ratios (ICERs) per quality adjusted life year (QALY) gained. The results of the pairwise analysis show that all lead-I ECG devices generate ICERs per QALY gained below the £20,000-£30,000 threshold. Kardia Mobile is the most cost effective option in a full incremental analysis. Lead-I ECG tests may identify more AF cases than the standard diagnostic pathway. This comes at a higher cost but with greater patient benefit in terms of mortality and quality of life. LIMITATIONS: No published data evaluating the diagnostic accuracy, clinical impact or cost effectiveness of lead-I ECG devices for the target population are available. CONCLUSIONS: The use of single-time point lead-I ECG devices in primary care for the detection of AF in people with signs or symptoms of AF and an irregular pulse appears to be a cost effective use of NHS resources compared with MPP followed by a 12-lead ECG, given the assumptions used in the base case model. REGISTRATION: The protocol for this review is registered on PROSPERO as CRD42018090375.


Assuntos
Fibrilação Atrial/diagnóstico , Eletrocardiografia/métodos , Idoso , Idoso de 80 Anos ou mais , Análise Custo-Benefício , Eletrocardiografia/economia , Eletrocardiografia/instrumentação , Feminino , Humanos , Masculino , Cadeias de Markov , Pessoa de Meia-Idade , Atenção Primária à Saúde/economia , Atenção Primária à Saúde/métodos , Pulso Arterial
8.
Sensors (Basel) ; 19(21)2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31683718

RESUMO

Fabry-Perot interferometric (FPI) sensors are an accurate and well-established sensing technology that are used to monitor a wide range of parameters such as strain, temperature, and refractive index, among many others. Nevertheless, due to the limited number and high cost of existing interrogation techniques for FPIs, its use is often restricted to discrete measurements, not being so explored for dynamic applications. The development of an alternative interrogation technique for a high rate of acquisition may propel this type of sensor into less explored fields such as dynamic biomedical applications. In this work, we present the theoretical and experimental analyses of an FPI sensing architecture by using an alternative high rate dynamic acquisition methodology, based on frequency to amplitude conversion, where the FPI spectral shift is detuned by the convolution of the optical light source with the FPI interference pattern. The good agreement between the theoretical and experimental results verified the reliability of the proposed methodology. Moreover, preliminary results show that the developed sensing architecture can be a suitable solution to monitor biomedical parameters such as the carotid pulse wave.


Assuntos
Tecnologia Biomédica/instrumentação , Interferometria/instrumentação , Monitorização Fisiológica/instrumentação , Algoritmos , Materiais Biocompatíveis/química , Simulação por Computador , Humanos , Ácido Láctico/química , Fibras Ópticas , Impressão Tridimensional , Pulso Arterial
11.
Biomed Res Int ; 2019: 3252178, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31355255

RESUMO

The low cost, simple, noninvasive, and continuous measurement of cerebral blood flow velocity (CBFV) by transcranial Doppler is becoming a common clinical tool for the assessment of cerebral hemodynamics. CBFV monitoring can also help with noninvasive estimation of intracranial pressure and evaluation of mild traumatic brain injury. Reliable CBFV waveform analysis depends heavily on its accurate beat-to-beat delineation. However, CBFV is inherently contaminated with various types of noise/artifacts and has a wide range of possible pathological waveform morphologies. Thus, pulse onset detection is in general a challenging task for CBFV signal. In this paper, we conducted a comprehensive comparative analysis of three popular pulse onset detection methods using a large annotated dataset of 92,794 CBFV pulses-collected from 108 subarachnoid hemorrhage patients admitted to UCLA Medical Center. We compared these methods not only in terms of their accuracy and computational complexity, but also for their sensitivity to the selection of their parameters' values. The results of this comprehensive study revealed that using optimal values of the parameters obtained from sensitivity analysis, one method can achieve the highest accuracy for CBFV pulse onset detection with true positive rate (TPR) of 97.06% and positive predictivity value (PPV) of 96.48%, when error threshold is set to just less than 10 ms. We conclude that the high accuracy and low computational complexity of this method (average running time of 4ms/pulse) makes it a reliable algorithm for CBFV pulse onset detection.


Assuntos
Circulação Cerebrovascular , Fluxo Pulsátil , Pulso Arterial , Hemorragia Subaracnóidea , Ultrassonografia Doppler Transcraniana , Adulto , Velocidade do Fluxo Sanguíneo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Hemorragia Subaracnóidea/diagnóstico por imagem , Hemorragia Subaracnóidea/fisiopatologia
12.
Biosensors (Basel) ; 9(3)2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31295893

RESUMO

This paper compares the structural design of two organic biosensors that minimize power consumption in wireless photoplethysmogram (PPG) waveform monitoring. Both devices were fabricated on the same substrate with a red organic light-emitting diode (OLED) and an organic photodiode (OPD). Both were designed with a circular OLED at the center of the device surrounded by OPD. One device had an OLED area of 0.06 cm2, while the other device had half the area. The gap distance between the OLED and OPD was 1.65 mm for the first device and 2 mm for the second. Both devices had an OPD area of 0.16 cm2. We compared the power consumption and signal-to-noise ratio (SNR) of both devices and evaluated the PPG signal, which was successfully collected from a fingertip. The reflectance-based organic pulse meter operated successfully and at a low power consumption of 8 µW at 18 dB SNR. The device sent the PPG waveforms, via Bluetooth low energy (BLE), to a PC host at a maximum rate of 256 kbps data throughput. In the end, the proposed reflectance-based organic pulse meter reduced power consumption and improved long-term PPG wireless monitoring.


Assuntos
Técnicas Biossensoriais , Fotopletismografia/instrumentação , Fotopletismografia/métodos , Pulso Arterial , Tecnologia sem Fio , Desenho de Equipamento , Frequência Cardíaca , Humanos , Dispositivos Ópticos , Razão Sinal-Ruído
14.
J Surg Res ; 243: 301-308, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31254903

RESUMO

BACKGROUND: There currently are no well-defined animal models for traumatic pulseless electrical activity (PEA). Our objective was to develop a swine model of traumatic PEA that would be useful for laboratory research where mortality is an outcome of interest. In this pilot study, we hypothesized that animals that remained in PEA without intervention for a longer period would have increased mortality. MATERIALS AND METHODS: Sixteen Yorkshire swine were alternately allocated to either 5 or 10 min of traumatic PEA without intervention. After the nonintervention period, basic life support (BLS) with mechanical cardiopulmonary resuscitation was initiated and performed for 10 min followed by advanced life support (ALS) for an additional 10 min. Hemodynamic and laboratory values are reported for baseline, posthemorrhage, end of BLS, and end of ALS periods. RESULTS: Mortality in the 10-min PEA group (100%) was higher than the 5-min group (38%) (P = 0.03). Animals in the 5-min group had improved aortic diastolic blood pressure, coronary perfusion pressure, and end-tidal CO2 at the end of both the BLS (P = 0.02, 0.002, and 0.02, respectively) and ALS (P = 0.009, 0.005, and 0.008, respectively). The 10-min animals had increased hyperkalemia at the end of the BLS (P = 0.004) and ALS (P = 0.005) periods. All animals in the 10-min group developed ventricular fibrillation (VF) and 38% of the 5-min animals developed VF (P = 0.03). CONCLUSIONS: In our pilot study of traumatic PEA in a swine model, a shorter period of nonintervention resulted in increased survival, improved hemodynamics during resuscitation, decreased hyperkalemia, and less incidence of conversion to VF arrest.


Assuntos
Reanimação Cardiopulmonar , Modelos Animais de Doenças , Parada Cardíaca , Hipovolemia , Ferimentos e Lesões/complicações , Animais , Feminino , Projetos Piloto , Pulso Arterial , Suínos , Fatores de Tempo
15.
Injury ; 50(9): 1507-1510, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31147183

RESUMO

BACKGROUND: Generally considered a sign of life, PEA is the most common arrhythmia encountered following pre-hospital traumatic cardiac arrest. Some recommend cardiac ultrasound (CUS) to determine cardiac wall motion (CWM) prior to terminating resuscitation efforts. This purpose of this study was to evaluate the outcomes of patients with traumatic cardiac arrest presenting with PEA, with and without CWM. METHODS: Trauma patients who underwent pre-hospital CPR were identified from the registries of two level-1 trauma centers. Pre-hospital management by emergency medical transport services was guided by advanced life support protocols. The on-duty trauma surgeon directed the resuscitations and performed or supervised CUS and determined CWM. RESULTS: Among 277 patients who underwent pre-hospital CPR, 110 patients had PEA on arrival to ED. 69 (62.7%) were injured by blunt mechanisms. Median CPR duration was 20.0 and 8.0 min for pre-hospital and ED, respectively. Sixty-three patients (22.7%) underwent resuscitative thoracotomy. One hundred seventy-two patients (62.1%) received CUS and of these 32 (18.6%) had CWM. CWM was significantly associated with survival to hospital admission (21.9% vs. 1.4%; P < 0.001); however, no patient with CUS survived to hospital discharge. Overall, only one patient with PEA on arrival survived to discharge. CONCLUSION: Following pre-hospital traumatic cardiac arrest, PEA on arrival portends death. Although CWM is associated with survival to admission, it is not associated with meaningful survival. Heroic resuscitative measures may be unwarranted for PEA following pre-hospital traumatic arrest, regardless of CWM.


Assuntos
Reanimação Cardiopulmonar/métodos , Serviços Médicos de Emergência/métodos , Parada Cardíaca/fisiopatologia , Pulso Arterial/instrumentação , Adulto , Reanimação Cardiopulmonar/mortalidade , Eletrocardiografia , Feminino , Parada Cardíaca/classificação , Parada Cardíaca/mortalidade , Parada Cardíaca/terapia , Humanos , Masculino , Futilidade Médica , Pessoa de Meia-Idade , Estudos Retrospectivos , Estatísticas não Paramétricas , Adulto Jovem
16.
Anesth Analg ; 128(6): 1145-1151, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31094781

RESUMO

BACKGROUND: Pulse pressure variation (PPV) can be used to predict fluid responsiveness in anesthetized patients receiving controlled mechanical ventilation but usually requires dedicated advanced monitoring. Capstesia (Galenic App, Vitoria-Gasteiz, Spain) is a novel smartphone application that calculates PPV and cardiac output (CO) from a picture of the invasive arterial pressure waveform obtained from any monitor screen. The primary objective was to compare the ability of PPV obtained using the Capstesia (PPVCAP) and PPV obtained using a pulse contour analysis monitor (PPVPC) to predict fluid responsiveness. A secondary objective was to assess the agreement and the trending of CO values obtained with the Capstesia (COCAP) against those obtained with the transpulmonary bolus thermodilution method (COTD). METHODS: We studied 57 mechanically ventilated patients (tidal volume 8 mL/kg, positive end-expiratory pressure 5 mm Hg, respiratory rate adjusted to keep end tidal carbon dioxide [32-36] mm Hg) undergoing elective coronary artery bypass grafting. COTD, COCAP, PPVCAP, and PPVPC were measured before and after infusion of 5 mL/kg of a colloid solution. Fluid responsiveness was defined as an increase in COTD of >10% from baseline. The ability of PPVCAP and PPVPC to predict fluid responsiveness was analyzed using the area under the receiver-operating characteristic curve (AUROC), the agreement between COCAP and COTD using a Bland-Altman analysis and the trending ability of COCAP compared to COTD after volume expansion using a 4-quadrant plot analysis. RESULTS: Twenty-eight patients were studied before surgical incision and 29 after sternal closure. There was no significant difference in the ability of PPVCAP and PPVPC to predict fluid responsiveness (AUROC 0.74 [95% CI, 0.60-0.84] vs 0.68 [0.54-0.80]; P = .30). A PPVCAP >8.6% predicted fluid responsiveness with a sensitivity of 73% (95% CI, 0.54-0.92) and a specificity of 74% (95% CI, 0.55-0.90), whereas a PPVPC >9.5% predicted fluid responsiveness with a sensitivity of 62% (95% CI, 0.42-0.88) and a specificity of 74% (95% CI, 0.48-0.90). When measured before surgery, PPV predicted fluid responsiveness (AUROC PPVCAP = 0.818 [P = .0001]; PPVPC = 0.794 [P = .0007]) but not when measured after surgery (AUROC PPVCAP = 0.645 [P = .19]; PPVPC = 0.552 [P = .63]). A Bland-Altman analysis of COCAP and COTD showed a mean bias of 0.3 L/min (limits of agreement: -2.8 to 3.3 L/min) and a percentage error of 60%. The concordance rate, corresponding to the proportion of CO values that changed in the same direction with the 2 methods, was poor (71%, 95% CI, 66-77). CONCLUSIONS: In patients undergoing cardiac surgery, PPVCAP and PPVPC both weakly predict fluid responsiveness. However, COCAP is not a good substitute for COTD and cannot be used to assess fluid responsiveness.


Assuntos
Determinação da Pressão Arterial/instrumentação , Pressão Sanguínea , Débito Cardíaco , Procedimentos Cirúrgicos Cardíacos , Monitorização Intraoperatória/instrumentação , Pulso Arterial , Smartphone , Adulto , Idoso , Algoritmos , Área Sob a Curva , Pressão Arterial , Determinação da Pressão Arterial/métodos , Feminino , Hidratação , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Aplicativos Móveis , Monitorização Intraoperatória/métodos , Estudos Prospectivos , Curva ROC , Reprodutibilidade dos Testes , Respiração Artificial , Termodiluição/métodos
17.
Biomech Model Mechanobiol ; 18(6): 1629-1638, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31073807

RESUMO

Arterial wall parameters (i.e., radius and viscoelasticity) are prognostic markers for cardiovascular diseases (CVD), but their current monitoring systems are too complex for home use. Our objective was to investigate whether model-based analysis of arterial pulse signals allows tracking changes in arterial wall parameters using a microfluidic-based tactile sensor. The sensor was used to measure an arterial pulse signal. A data-processing algorithm was utilized to process the measured pulse signal to obtain the radius waveform and its first-order and second-order derivatives, and extract their key features. A dynamic system model of the arterial wall and a hemodynamic model of the blood flow were developed to interpret the extracted key features for estimating arterial wall parameters, with no need of calibration. Changes in arterial wall parameters were introduced to healthy subjects ([Formula: see text]) by moderate exercise. The estimated values were compared between pre-exercise and post-exercise for significant difference ([Formula: see text]). The estimated changes in the radius, elasticity and viscosity were consistent with the findings in the literature (between pre-exercise and 1 min post-exercise: - 11% ± 4%, 55% ± 38% and 28% ± 11% at the radial artery; - 7% ± 3%, 36% ± 28% and 16% ± 8% at the carotid artery). The model-based analysis allows tracking changes in arterial wall parameters using a microfluidic-based tactile sensor. This study shows the potential of developing a solution to at-home monitoring of the cardiovascular system for early detection, timely intervention and treatment assessment of CVD.


Assuntos
Artérias/fisiologia , Modelos Cardiovasculares , Pulso Arterial , Processamento de Sinais Assistido por Computador , Adulto , Algoritmos , Elasticidade , Exercício Físico , Feminino , Frequência Cardíaca/fisiologia , Hemodinâmica , Humanos , Masculino , Microfluídica , Pessoa de Meia-Idade , Projetos Piloto , Análise de Onda de Pulso , Resistência Vascular
18.
Clin Podiatr Med Surg ; 36(3): 361-370, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31079603

RESUMO

The accurate assessment of peripheral perfusion is a critical step in caring for a diabetic patient with active ulceration. This article guides the provider through diagnostic and therapeutic options. The perfusion assessment begins with a physical examination and augmented using noninvasive tests. Although some of these tests can be performed at the bedside, often a dedicated vascular laboratory is required. Additional cross-sectional imaging studies or formal angiography should be performed as well. These tools aid in the creation of the best therapeutic plan, which aims to restore perfusion and allow for rapid wound healing via open or endovascular means.


Assuntos
Diabetes Mellitus/fisiopatologia , Pé Diabético/cirurgia , Doença Arterial Periférica/diagnóstico , Doença Arterial Periférica/cirurgia , Índice Tornozelo-Braço , Circulação Sanguínea/fisiologia , Pressão Sanguínea/fisiologia , Pé Diabético/diagnóstico por imagem , Diagnóstico por Imagem , Procedimentos Endovasculares , Pé/irrigação sanguínea , Pé/diagnóstico por imagem , Humanos , Doença Arterial Periférica/fisiopatologia , Exame Físico , Pulso Arterial , Procedimentos Cirúrgicos Vasculares
19.
Nat Biomed Eng ; 3(1): 47-57, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30932072

RESUMO

The ability to monitor blood flow is critical to patient recovery and patient outcomes after complex reconstructive surgeries. Clinically available wired implantable monitoring technology requires careful fixation for accurate detection and needs to be removed after use. Here, we report the design of a pressure sensor, made entirely of biodegradable materials and based on fringe-field capacitor technology, for measuring arterial blood flow in both contact and non-contact modes. The sensor is operated wirelessly through inductive coupling, has minimal hysteresis, fast response times, excellent cycling stability, is highly robust, allows for easy mounting and eliminates the need for removal, thus reducing the risk of vessel trauma. We demonstrate the operation of the sensor with a custom-made artificial artery model and in vivo in rats. This technology may be advantageous in real-time post-operative monitoring of blood flow after reconstructive surgery.


Assuntos
Artérias/fisiologia , Circulação Sanguínea/fisiologia , Monitorização Fisiológica/instrumentação , Pulso Arterial/instrumentação , Tecnologia sem Fio/instrumentação , Anastomose Cirúrgica , Animais , Artérias/cirurgia , Desenho de Equipamento , Maleabilidade , Ratos Sprague-Dawley
20.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 36(2): 298-305, 2019 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-31016948

RESUMO

The extraction of pulse rate variability(PRV) in daily life is often affected by exercise and blood perfusion. Therefore, this paper proposes a method of detecting pulse signal and extracting PRV in post-ear, which could improve the accuracy and stability of PRV in daily life. First, the post-ear pulse signal detection system suitable for daily use was developed, which can transmit data to an Android phone by Bluetooth for daily PRV extraction. Then, according to the state of daily life, nine experiments were designed under the situation of static, motion, chewing, and talking states, respectively. Based on the results of these experiments, synchronous data acquisition of the single-lead electrocardiogram (ECG) signal and the pulse signal collected by the commercial pulse sensor on the finger were compared with the post-auricular pulse signal. According to the results of signal wave, amplitude and frequency-amplitude characteristic, the post-ear pulse signal was significantly steady and had more information than finger pulse signal in the traditional way. The PRV extracted from post-ear pulse signal has high accuracy, and the accuracy of the nine experiments is higher than 98.000%. The method of PRV extraction from post-ear has the characteristics of high accuracy, good stability and easy use in daily life, which can provide new ideas and ways for accurate extraction of PRV under unsupervised conditions.


Assuntos
Eletrocardiografia Ambulatorial , Frequência Cardíaca , Orelha , Dedos , Humanos , Monitorização Ambulatorial , Movimento (Física) , Pulso Arterial
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