Cardiovascular Fitness in Normal Weight and Obese Children and Adolescents - A Systematic Review of Studies Published After 2000s / Condición Cardiovascular en Niños y Adolescentes con Peso Normal y Obesos: Una Revisión Sistemática de Estudios Publicados Después de la Década del 2000

SUMMARY: The primary aim was to gather available data published after the 2000s, on cardiovascular fitness in normal weight and obese children and adolescents. Based on the data, the secondary aims were to identify the most used outcomes and to determine the differences in cardiovascular fitness in the mentioned populations. Following PRISMA recommendations, multiple databases were searched: Google Scholar, PubMed, Cochrane Library, ProQuest, and Research Gate, with additional inclusion criteria: original study published in English, normal weight and obese children and adolescents as participant sample, studies that have assessed cardiovascular fitness parameters, and studies with participant's nutrition state. A total of 19 studies, with a total of 4,988 included participants (both obese and normal weight) were identified, with the most common participants have presented better results in terms of BMI, BF%, VO2max, VO2peak and METs, while the HR values are inconsistently presented. Despite deficiencies the study deficiency in the last two decades, there are differences in the mentioned populations. Further studies should focus on including the technology that reaches teens and families for overweight and obesity prevention and advancements in standard measurements for juvenile overweight and obesity, as well as for the creation, adaption, and validation of measuring instruments. As good framework for future directions, there is a need for more concise and unified measurements of cardiovascular fitness parameters in normally weight and obese children and adolescents.

El objetivo principal fue recopilar datos disponibles publicados después de la década del 2000 sobre la condición cardiovascular en niños y adolescentes con peso normal y obesos. En base a estos datos, los objetivos secundarios fueron identificar los resultados más utilizados y determinar las diferencias en la condición cardiovascular en las poblaciones mencionadas. Siguiendo las recomendaciones de PRISMA, se realizaron búsquedas en múltiples bases de datos: Google Scholar, PubMed, Cochrane Library, ProQuest y Research Gate, con criterios de inclusión adicionales: estudio original publicado en inglés, niños y adolescentes con peso normal y obesidad como muestra participante, estudios que hayan evaluado enfermedades cardiovasculares, parámetros de condición física y estudios con el estado nutricional de los participantes. Se identificaron un total de 19 estudios, con un total de 4.988 participantes incluidos (tanto obesos como con peso normal), siendo las variables más comunes: IMC, %BF, VO2máx, VO2pico, FC, PAD, PAS y MET. Generalmente, los participantes con peso normal han presentado mejores resultados en términos de IMC, %BF, VO2máx, VO2peak y MET, mientras que los valores de FC se presentan de manera inconsistente. Independientemente de la deficiencia de estudios en las últimas dos décadas, existen diferencias en las poblaciones mencionadas. Estudios futuros deberían centrarse en incluir tecnología que llegue a adolescentes y familias para la prevención del sobrepeso y la obesidad y avances en las mediciones estándar del sobrepeso y la obesidad juvenil, así como para la creación, adaptación y validación de instrumentos de medición. Como buen marco para direcciones futuras, se necesitan mediciones más concisas y unificadas de los parámetros de la condición cardiovascular en niños y adolescentes con peso normal y obesos.

Efeitos do exercício intradialítico sobre a qualidade do sono e a modulação autonômica cardíaca / Effects of intradialytic exercise on sleep quality and cardiac autonomic modulation / Efectos del ejercicio intradialítico sobre la calidad del sueño y la modulación autonómica cardíaca

Objetivo: avaliar os efeitos de um programa de exercício resistido intradialítico sobre a qualidade do sono e a modulação autonômica cardíaca de pacientes em hemodiálise. Método: ensaio clínico não randomizado, realizado entre fevereiro de 2019 e outubro de 2020, com 52 indivíduos renais crônicos dialíticos, alocados em grupo intervenção (GI; n=32) e grupo controle (GC; n=20). O GI realizou 12 semanas de treinamento físico intradialítico, três vezes por semana. Foram mensurados índices de qualidade do sono e modulação autonômica cardíaca. Resultados: houve incremento nos índices desvio padrão dos intervalos batimento a batimento (SDNN) (ms) (p=0,0004), raiz quadrada da média do quadrado dos intervalos batimento a batimento adjacentes (RMSSD) (ms) (p<0,0001), desvio padrão 1 (SD1) (ms) (p=0,03) e razão desvio padrão 1/desvio padrão 2 (SD1/SD2) (p=0,0003). Não houve melhora da qualidade do sono. Conclusão: O exercício resistido intradialítico, é capaz de melhorar a modulação autonômica cardíaca em pacientes com doença renal crônica(AU)

Objective: to evaluate the effects of an intradialytic resistance exercise program on sleep quality and cardiac autonomic modulation in hemodialysis patients. Method: non-randomized clinical trial, carried out between February 2019 and October 2020, with 52 individuals with chronic renal failure on dialysis, divided into an intervention group (IG; n=32) and a control group (CG; n=20). The IG performed 12 weeks of intradialytic physical training, three times a week. Indices of sleep quality and cardiac autonomic modulation were measured. Results: there was an increase in the standard deviation indices of beat-to-beat intervals (SDNN) (ms) (p=0.0004), square root of the mean square of adjacent beat-to-beat intervals (RMSSD) (ms) (p<0. 0001), standard deviation 1 (SD1) (ms) (p=0.03) and standard deviation 1/standard deviation 2 (SD1/SD2) ratio (p=0.0003). There was no improvement in sleep quality. Conclusion: Intradialytic resistance exercise is able to improve cardiac autonomic modulation in patients with chronic kidney disease(AU)

Objetivo: evaluar los efectos de un programa de ejercicios de resistencia e intradialíticos sobre la calidad del sueño y la modulación autonómica cardíaca en pacientes en hemodiálisis. Método: ensayo clínico no aleatorizado, realizado entre febrero de 2019 y octubre de 2020, junto a 52 individuos en diálisis con insuficiencia renal crónica, divididos en grupo intervención (GI; n=32) y grupo control (GC; n=20). El GI realizó 12 semanas de entrenamiento físico intradialítico, tres veces por semana. Se midieron índices de calidad del sueño y modulación autonómica cardíaca. Resultados: hubo un aumento en los índices de desviación estándar de los intervalos entre latidos (SDNN) (ms) (p=0,0004), raíz cuadrada del cuadrado medio de los intervalos entre latidos adyacentes (RMSSD) (ms) (p<0,0001), desviación estándar 1 (DE1) (ms) (p=0,03) y relación desviación estándar 1/desviación estándar 2 (DE1/DE2) (p=0,0003). No hubo mejoría en la calidad del sueño. Conclusión: el ejercicio de resistencia intradialítico puede mejorar la modulación autonómica cardíaca en pacientes con enfermedad renal crónica(AU)

Las ecuaciones predictoras de frecuencia cardiaca máxima no superan prueba clave de validación externa / Maximum heart rate prediction equations fail key external validation test / Equações de predição da frequência cardíaca máxima não superam teste-chave de validação externa

Resumen Las ecuaciones de frecuencia cardiaca máxima (FCmax) se han utilizado por su fácil obtención y practicidad, en comparación con las pruebas de esfuerzo. Sin embargo, la ecuación más conocida "220 − edad" presenta baja fiabilidad y desviaciones de hasta 12 lat/min. Se han planteado nuevas fórmulas, pero estas no han sido correctamente validadas. El propósito de este estudio fue validar 7 ecuaciones de predicción utilizando una base de datos independiente. Se utiliza una base con datos de 634 sujetos (474 hombres y 160 mujeres) de 18-85 años, que fueron obtenidos como parte de un servicio de salud desarrollado en la Universidad de Michigan entre 1990-1992. Los sujetos realizaron una prueba de vO2max en banda sin fin, siguiendo un protocolo libre. Se utilizó la técnica de regresión lineal, en la que las ecuaciones adecuadas fueron aquellas que cumplieron con las dos hipótesis: pendiente = 1 y constante = 0. De acuerdo con los resultados, ninguna de las ecuaciones analizadas para toda la muestra aceptó ambas hipótesis. Al realizar el análisis de acuerdo con el sexo, seis de las ecuaciones cumplieron con las dos hipótesis para las mujeres, pero ninguna para los hombres; y, cuando se realizó de acuerdo con el grupo de edad, 4 de las ecuaciones cumplieron las hipótesis para el grupo de personas de 40 años o menos, pero no para el grupo de mayores de 40 años. La FCmax parece ser difícil de predecir por una única ecuación, por lo que se recomienda que, cuando se necesite una medida válida de esta variable, se recurra a una prueba directa.

Abstract Maximum heart rate equations (HRmax) have been used due to their easy availability and practicality, as compared to stress tests. However, the best-known equation, "220 - age", shows low reliability and deviations of up to 12 beats/min. New formulae have been proposed, but they have not been correctly validated. The purpose of this study was to validate 7 prediction equations by using and independent data base. A data base of 634 subjects (474 men and 160 women) from 18-85 years of age, obtained within a health service developed at the University of Michigan from 1990-1992, has been used. The subjects performed a vO2max test in a treadmill, following a free protocol. A linear regression technique was used in which the appropriate equations were those that met the two hypotheses: slope = 1 and constant = 0. According to the results, none of the equations analyzed for the full sample accepted both hypotheses. When doing the analysis by sex, six of the equations met the two hypotheses for the women, but none of them for the men; and when the analysis was done by age group, 4 of the equations met the hypotheses for the group 40 years old or younger, but not for those above 40. The HRmax seems to be difficult to predict through a single equation. Therefore, it is recommended that, when a valid measure for this variable is needed, a stress test be used.

Resumo As equações de predição da frequência cardíaca máxima (FCmax) têm sido utilizadas devido à sua facilidade de obtenção e praticidade, quando comparadas aos testes de esforço. No entanto, a equação mais conhecida "220 − idade" apresenta baixa confiabilidade e desvios de até 12 batimentos/min. Foram propostas novas fórmulas, entretanto não foram devidamente validadas. O objetivo deste estudo foi validar 7 equações de predição usando um banco de dados independente. Utiliza-se um banco de dados de 634 indivíduos (474 homens e 160 mulheres) com idades entre 18 e 85 anos, obtidos como parte de um serviço de saúde desenvolvido na Universidade de Michigan entre 1990-1992. Os sujeitos realizaram um teste de vO2máx em uma esteira, seguindo um protocolo livre. Utilizou-se a técnica de regressão linear, na qual as equações apropriadas foram aquelas que preencheram as duas hipóteses: inclinação = 1 e constante = 0. De acordo com os resultados, nenhuma das equações analisadas para toda a amostra aceitou ambas as hipóteses. Ao realizar a análise por sexo, seis das equações atenderam às duas hipóteses para as mulheres, mas nenhuma para os homens; e, quando realizadas de acordo com a faixa etária, 4 das equações atenderam às hipóteses para o grupo de pessoas com 40 anos ou menos, mas não para o grupo de pessoas com mais de 40 anos. A FCmax parece ser difícil de prever por uma única equação, por isso recomenda-se que, quando uma medida válida dessa variável for necessária, seja utilizado um teste direto.

Efficacy of a single dose of esmolol to prevent extubation-related complications during emergence from anesthesia: a randomized, double-blind, placebo-controlled trial

Abstract Background Few trials have examined the efficacy of esmolol to attenuate hemodynamic and respiratory responses during extubation. However, the most appropriate dose of esmolol and an optimal protocol for administering this beta-blocker are uncertain. Methods Ninety patients ASA physical status I, II, and III (aged 18-60 years) scheduled to procedures with general anesthesia and tracheal extubation were selected. Patients were randomized into esmolol and placebo group to evaluate the efficacy and safety of a single bolus dose of esmolol (2 mg.kg-1) on cardiorespiratory responses during the peri-extubation period. The primary outcome was the rate of tachycardia during extubation. Results The rate of tachycardia was significantly lower in esmolol-treated patients compared to placebo-treated patients (2.2% vs. 48.9%, relative risk (RR): 0.04, 95% confidence interval (95% CI) = 0.01 to 0.32, p= 0.002). The rate of hypertension was also significantly lower in the esmolol group (4.4% vs. 31.1%, RR: 0.14, 95% CI 0.03 to 0.6, p= 0.004). Esmolol-treated patients were associated with higher extubation quality compared to patients who received placebo (p< 0.001), with an approximately two-fold increase in the rate of patients without cough (91.1%) in the esmolol group compared to the placebo group (46.7%). The rate of bucking was approximately 5-fold lower in the esmolol group (8.9% vs. 44.5%, respectively, RR: 0.20 (95% CI, 0.1 to 0.5, p= 0.002, with an NNT of 2.8). Conclusion A single bolus dose of esmolol is an effective and safe therapeutic strategy to attenuate cardiorespiratory responses during the peri-extubation period.

Relación del ritmo de repetición del CrossFit WOD Karen con la frecuencia cardíaca y el esfuerzo percibido / Relationship of Crossfit wod Karen repetition rate to heart rate and perceived exertion

Introducción: El CrossFit representa un paradigma interesante del fitness para los profesionales del ejercicio y la medicina deportiva. No obstante, aún se desconoce si el ritmo de repetición influye en las respuestas cardiovasculares y la percepción del esfuerzo en este tipo de entrenamiento físico. Objetivo: Relacionar el ritmo de repetición del CrossFit WOD Karen con la frecuencia cardíaca y el esfuerzo percibido en sujetos físicamente activos. Métodos: Se realizó un estudio descriptivo-correlacional de enfoque cuantitativo a una muestra no probabilística de 20 sujetos. Durante la aplicación de la prueba WOD Karen y el test Course-Navette, la frecuencia cardíaca se monitoreó a través de pulsómetros Polar H7; el esfuerzo percibido se valoró con la escala de Borg CR-10 y el ritmo de repetición se calculó mediante una ecuación matemática. Los datos se analizaron con el paquete estadístico PSPP y se empleó el coeficiente de correlación de Spearman. Resultados: La intensidad relativa del entrenamiento (r = -0,67) y la percepción subjetiva del esfuerzo (r = -0,68) se relacionan negativamente en las mujeres. En ambos sexos no existió significación (p < 0,05). Conclusión: Las mujeres con un ritmo de repetición más rápido presentaron una frecuencia cardíaca y un esfuerzo percibido más bajo(AU)

Introduction: CrossFit represents an interesting fitness paradigm for exercise and sports medicine professionals. However, it is still unknown whether the repetition rate of this type of physical training influences cardiovascular responses and perceived exertion. Objective: To find the relation between the repetition rate of the CrossFit WOD Karen to heart rate and the perceived exertion in physically active subjects. Methods: A descriptive-correlational study with a quantitative approach was performed with a non-probabilistic sample of 20 subjects. During the application of the WOD Karen test and the Course-Navette test, heart rate was monitored with pulsometers; perceived exertion was assessed through the Borg CR-10 scale and repetition rate was calculated using a mathematical equation. Data were analyzed with the PSPP statistical package and the Spearman's correlation coefficient was used. Results: Relative training intensity (r = -0.67) and subjective perception of effort (r = -0.68) were negatively related in women. In both genders there was no significance (p < 0.05). Conclusion: Women with a faster repetition rate had a lower heart rate and lower perceived exertion(AU)

Premature newborn positionings and physiologic parameters - a randomized clinical study / Posicionamentos de recém-nascidos prematuros e parâmetros fisiológicos - um estudo clínico randomizado

Abstract Introduction Multiple studies have shown the effects of prone (PP), supine (SP) and kangaroo (KP) positions on clinical and physiological outcomes in preterm newborns, but none compared these three types of positioning between them. Objective To investigate the influence of these positionings on heart rate, respiratory rate, peripheral oxygen saturation (SpO2) and alertness status in clinically stable preterm newborns (NBs) admitted to a neonatal intensive care unit. Methods In a randomized clinical trial, clinically stable NBs with gestational ages from 30 to 37 weeks who were breathing spontaneously were allocated in three positioning groups: PP, SP and KP. Heart rate, breathing frequency, SpO2 and alertness status were evaluated immediately before and after 30 minutes of positioning. Results In all, 66 NBs were assessed (corrected age: 35.48 ± 1.94 weeks; weight: 1840.14 ± 361.09 g), (PP: n = 22; SP: n = 23; KP: n = 21). NBs in the PP group showed a significant improvement in peripheral SpO2 (97.18 ± 2.16 vs 95.47 ± 2.93 vs 95.57 ± 2.95, p = 0.03) compared with the SP and KP groups. Conclusion In clinically stable preterm NBs, the PP was associated with better peripheral oxygen saturation than the SP or KP. In addition, there was a reduction in heart rate within prone position group and in the KP group there was an increase in the number of NBs in the deep sleep classification.

Resumo Introdução Vários estudos têm demonstrado os efeitos das posições prona (PP), supina (SP) e canguru (KP) sobre os resul-tados clínicos e fisiológicos em recém-nascidos prematuros, mas nenhum comparou esses três tipos de posicionamento. Objetivo Investigar a influência desses posicionamentos na frequência cardíaca, frequência respiratória, saturação periférica de oxigênio (SpO2) e estado de alerta em recém-nascidos pré-termo (RN) clinicamente estáveis internados em uma unidade de terapia intensiva neonatal. Métodos Em um ensaio clínico randomizado, RN clinicamente estáveis com idade gestacional de 30 a 37 semanas e respirando espontaneamente foram alocados em três grupos de posicionamento: PP, SP e KP. Frequência cardíaca e respiratória, SpO2 e estado de alerta foram avaliados imediatamente antes e após 30 minutos de posicionamento. Resultados Ao todo, foram avaliados 66 RNs (idade corrigida: 35,48 ± 1,94 semanas; peso: 1840,14 ± 361,09 g), (PP: n = 22; SP: n = 23; KP: n = 21). Os RNs do grupo PP apresentaram melhora significativa na SpO2 periférica (97,18 ± 2,16 vs 95,47 ± 2,93 vs 95,57 ± 2,95, p = 0,03) em comparação aos grupos SP e KP. Conclusão Em RN prematuros clinicamente estáveis, o PP foi associado à melhor saturação periférica de oxigênio do que o SP ou KP. Além disso, houve redução da frequência cardíaca no grupo de posição prona e no grupo KP houve aumento do número de RNs na classificação sono profundo.

Analysis of the impact of different exercise methods on the physical health of obese adolescents / Análise do impacto entre diferentes métodos de exercício na saúde física de adolescentes obesos / Análisis del impacto entre diferentes métodos de ejercicio en la salud física de adolescentes obesos

ABSTRACT Introduction: The unregulated development in the current life pattern has strengthened obesity among adolescents, and this problem is becoming more serious. Objective: Compare the impact of two exercise methods on the physical health of obese adolescents. Methods: 24 obese adolescents (12 females; BMI>30% ± 3%; age concentrated between 10 and 16 years) were selected and divided into group I and group II for a 4-week experimental study, and changes in physical fitness and function were recorded. Results: After four weeks of aerobic exercise control (group I), waist circumference, hip circumference, skinfold thickness, and abdominal fold thickness were significantly reduced in boys (p<0.05), and girls' body shape indicators were significantly altered (p<0.05). After four weeks of aerobic exercise combined with resistance training (group II), the effects of weight, BMI, and body size were significant in boys and girls. Conclusion: Aerobic exercise can effectively improve the physical problems of obese adolescents. Under the same external conditions, the effect of aerobic exercise was shown to be more effective when combined with resistance training in the physical improvement of the analyzed group. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: O desenvolvimento desregrado no padrão de vida atual fortaleceu a obesidade entre os adolescentes e esse problema está se tornando cada vez mais grave. Objetivo: Comparar o impacto entre dois métodos de exercício na saúde física de adolescentes obesos. Métodos: Foram selecionados 24 adolescentes obesos (12 mulheres; IMC>30% ± 3%; idade concentrada entre 10 e 16 anos) e divididos no grupo I e no grupo II para um estudo experimental de 4 semanas, sendo registradas as alterações no condicionamento e função física. Resultados: Após 4 semanas de controle de exercício aeróbico (grupo I), a circunferência da cintura, circunferência do quadril, espessura da dobra cutânea e espessura da dobra abdominal foram significativamente reduzidas em meninos (p<0,05), e os indicadores de forma corporal das meninas foram significativamente alterados (p<0,05). Após 4 semanas de exercício aeróbico combinado com treinamento de resistência (grupo II), os efeitos do peso, IMC e tamanho do corpo foram significativos em meninos e meninas. Conclusão: O exercício aeróbico pode melhorar efetivamente os problemas físicos dos adolescentes obesos. Sob as mesmas condições externas, o efeito do exercício aeróbico demonstrou-se mais eficaz quando aliado ao treinamento de resistência na melhoria física do grupo analisado. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: El desarrollo desordenado en el patrón de vida actual ha potenciado la obesidad entre los adolescentes y este problema es cada vez más grave. Objetivo: Comparar el impacto de dos métodos de ejercicio en la salud física de adolescentes obesos. Métodos: Se seleccionaron 24 adolescentes obesos (12 mujeres; IMC>30% ± 3%; edad concentrada entre 10 y 16 años) y se dividieron en el grupo I y el grupo II para un estudio experimental de 4 semanas, y se registraron los cambios en la aptitud física y la función. Resultados: Después de 4 semanas de control de ejercicio aeróbico (grupo I), la circunferencia de la cintura, la circunferencia de la cadera, el grosor de los pliegues cutáneos y el grosor de los pliegues abdominales se redujeron significativamente en los niños (p<0,05), y los indicadores de la forma corporal de las niñas se alteraron significativamente (p<0,05). Tras 4 semanas de ejercicio aeróbico combinado con entrenamiento de resistencia (grupo II), los efectos del peso, el IMC y el tamaño corporal fueron significativos en chicos y chicas. Conclusión: El ejercicio aeróbico puede mejorar eficazmente los problemas físicos de los adolescentes obesos. En las mismas condiciones externas, el efecto del ejercicio aeróbico se mostró más eficaz cuando se combinó con el entrenamiento de resistencia en la mejora física del grupo analizado. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Benefits of running on cardiac protection and the culture of exercise health awareness / Benefícios da corrida para a proteção cardíaca e a cultura da consciência sanitária do exercício / Beneficios de la carrera para la protección cardíaca y el cultivo de la conciencia de la salud del ejercicio

ABSTRACT Introduction: Several programs to encourage physical activity has been encouraged to reduce the sedentary lifestyle in China. Running is among them because it has potentially positive effects on cardiovascular diseases, hypertension, diabetes mellitus, and hypercholesterolemia, in addition to the intrinsic psychological and social benefits of outdoor sports. Objective: Explore the protective effect of running on the cardiac system by analyzing strategies for cultivating exercise health awareness. Methods: A group of ten healthy volunteers, five women aged 25-35 years, underwent a 45-minute running program, performed four times a week for three weeks. Data collected by spirometry and cardiac monitoring were collected, treated, compared, and discussed. This paper introduced the concept of subjective exercise intensity to find the best analysis and judgment of Cardiac Function. Finally, a quantitative investigation involving the analysis of 315 questionnaires explored the current status of sports health awareness in running fans. Results: Heart rate amplitude during running remained in the range of 120-160, belonging to the normal heart rate range for the surveyed audience. In most cases, women's heart rate was higher than men's (P<0.05). The exercise intensity was fixed at a frequency below the value of 16, which is a slightly strenuous stage, and the relative exercise intensity was controlled between 50% and 71.5%. Conclusion: Running has a good cardiac protective effect, and its followers are highly aware of sports health. Due to the beneficial effect of sports practice, its dissemination is recommended as a form of physical and social therapeutic activity. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: Com o intuito de reduzir o índice de sedentarismo na China, diversos programas de incentivo à atividade física foram estimulados. A corrida está dentre eles pois tem potenciais efeitos positivos nas doenças cardiovasculares, hipertensão arterial, diabetes mellitus e hipercolesterolemia, além dos benefícios psicológicos e sociais intrínsecos na prática esportiva ao ar livre. Objetivo: Explorar o efeito protetor da corrida no sistema cardíaco analisando as estratégias para a cultura da consciência sanitária do exercício. Métodos: Um grupo de dez voluntários saudáveis, com cinco mulheres e idade entre 25 a 35 anos foram submetidos a um programa de corrida por 45 minutos, realizado quatro vezes por semana, durante três semanas. Dados coletados por espirometria e monitoramento cardíaco foram coletados, tratados, comparados e discutidos. Este artigo introduziu o conceito de intensidade de exercício subjetivo para encontrar a melhor análise e julgamento da Função Cardíaca. Por fim, uma investigação quantitativa envolvendo a análise de 315 questionários explorou a situação atual da conscientização em saúde esportiva em adeptos da corrida. Resultados: A amplitude de frequência cardíaca durante a corrida manteve-se na faixa de 120-160, pertencente à faixa normal de frequência cardíaca ao público pesquisado. A frequência cardíaca das mulheres foi maior do que a dos homens na maioria dos casos (P<0,05). A intensidade do exercício fixou-se numa frequência inferior ao valor de 16, que é um estágio ligeiramente extenuante, e a intensidade relativa do exercício ficou controlada entre 50% e 71,5%. Conclusão: A corrida apresenta um bom efeito protetor cardíaco, seus adeptos possuem elevada conscientização da saúde esportiva. Devido ao efeito salutar da prática esportiva, recomenda-se a sua divulgação como forma de atividade terapêutica física e social. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: Con el fin de reducir el estilo de vida sedentario en China, se han estimulado varios programas para fomentar la actividad física. La carrera se encuentra entre ellos porque tiene potenciales efectos positivos sobre las enfermedades cardiovasculares, la hipertensión, la diabetes mellitus y la hipercolesterolemia, además de los beneficios psicológicos y sociales intrínsecos del deporte al aire libre. Objetivo: Explorar el efecto protector de correr sobre el sistema cardíaco analizando las estrategias para cultivar la conciencia de la salud del ejercicio. Métodos: Un grupo de diez voluntarios sanos, cinco mujeres, con edades comprendidas entre los 25 y los 35 años, fueron sometidos a un programa de carrera durante 45 minutos, realizado cuatro veces por semana durante tres semanas. Los datos recogidos por la espirometría y la monitorización cardíaca fueron recogidos, tratados, comparados y discutidos. Este trabajo introdujo el concepto de intensidad subjetiva del ejercicio para encontrar el mejor análisis y juicio de la Función Cardíaca. Por último, una investigación cuantitativa que incluyó el análisis de 315 cuestionarios exploró el estado actual de la conciencia de la salud deportiva en los aficionados a las carreras. Resultados: La amplitud de la frecuencia cardíaca durante la carrera se mantuvo en el rango de 120-160, perteneciendo al rango de frecuencia cardíaca normal para el público encuestado. La frecuencia cardíaca de las mujeres fue mayor que la de los hombres en la mayoría de los casos (P<0,05). La intensidad del ejercicio se fijó en una frecuencia inferior al valor de 16, que es una etapa ligeramente agotadora, y la intensidad relativa del ejercicio se controló entre el 50% y el 71,5%. Conclusión: La acción de correr presenta un buen efecto cardioprotector, sus adeptos poseen alta conciencia de la salud deportiva. Debido al efecto saludable de la práctica deportiva, se recomienda su difusión como forma de actividad terapéutica física y social. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Impact of high-intensity interval training on body mass index in college students / Impacto do treinamento intervalado de alta intensidade sobre o índice de massa corporal em estudantes universitários / Impacto del entrenamiento por intervalos de alta intensidad en el índice de masa corporal de estudiantes universitarios

ABSTRACT Introduction: Due to academic pressure, many college students feel unmotivated to exercise, leading to serious obesity problems. One of the effective resources for weight loss is high-intensity interval training, but there is no extensive research on the effect on this specific group. Objective: To explore the impact of high-intensity interval training on body fat index (BFI) in college students, analyzing the scientific basis and safety of this exercise training through heart rate indicators. Methods: Two experimental groups, MICT (moderate-intensity continuous training) and HIIT (high-intensity interval training), were compared. The HIIT group used stationary bicycles, according to the high-intensity interval training method. MICT is a moderate-intensity continuous training method, so the load was half that of the HIIT group. Results: The IGC of women after training was 22.81±2.87, the IGC was significantly reduced, and there was a very significant difference; the IGC of men after training was 22.74±2.12, the IGC was significantly reduced, and they very significant difference. This shows that the exercises have a good effect on weight loss. Conclusion: HIIT training is more effective, both in time and strength of adherence. It has a good effect on improving cardiopulmonary function, and optimizing IGC are strongly impacted. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: Devido à pressão acadêmica, muitos estudantes universitários sentem-se desmotivados para o exercício, acarretando a sérios problemas de obesidade. Um dos recursos eficazes para a perda de peso é o treinamento intervalado de alta intensidade, porém não há pesquisas amplas sobre o efeito nesse grupo específico. Objetivo: Explorar o impacto do treinamento intervalado de alta intensidade no índice de gordura corporal (IGC) dos estudantes universitários, analisando o embasamento científico e a segurança desse treinamento de exercício através dos indicadores de frequência cardíaca. Métodos: Dois grupos experimentais MICT (treinamento contínuo de intensidade moderada) e HIIT (treinamento intervalado de alta intensidade) foram comparados. O grupo HIIT utilizou bicicletas estacionárias, de acordo com o método de treinamento intervalado de alta intensidade. MICT é um método de treinamento contínuo de intensidade moderada, portanto a carga foi a metade do grupo HIIT. Resultados: O IGC das mulheres após o treinamento foi de 22,81±2,87, o IGC foi significativamente reduzido e houve uma diferença muito significativa, o IGC dos homens após o treinamento foi de 22,74±2,12, o IGC foi significativamente reduzido e houve uma diferença muito significativa. Isso mostra que os exercícios têm um bom efeito na perda de peso. Conclusão: O treinamento HIIT é mais eficaz, tanto em tempo quanto na resistência da adesão. Tem um bom efeito de melhora na função cardiopulmonar, sendo a otimização do IGC fortemente impactada. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: Debido a la presión académica, muchos estudiantes universitarios se sienten desmotivados para hacer ejercicio, lo que conduce a graves problemas de obesidad. Uno de los recursos efectivos para la pérdida de peso es el entrenamiento de intervalos de alta intensidad, sin embargo, no hay amplias investigaciones sobre el efecto en este grupo específico. Objetivo: Explorar el impacto del entrenamiento interválico de alta intensidad en el índice de grasa corporal (IGC) de estudiantes universitarios, analizando la base científica y la seguridad de este entrenamiento de ejercicio a través de indicadores de frecuencia cardíaca. Métodos: Se compararon dos grupos experimentales MICT (entrenamiento continuo de intensidad moderada) y HIIT (entrenamiento por intervalos de alta intensidad). El grupo HIIT utilizó bicicletas fijas, según el método de entrenamiento por intervalos de alta intensidad. El MICT es un método de entrenamiento continuo de intensidad moderada, por lo que la carga era la mitad que la del grupo HIIT. Resultados: El IGC de las mujeres después del entrenamiento fue de 22,81±2,87, el IGC se redujo significativamente y hubo una diferencia muy significativa, el IGC de los hombres después del entrenamiento fue de 22,74±2,12, el IGC se redujo significativamente y hubo una diferencia muy significativa. Esto demuestra que los ejercicios tienen un buen efecto en la pérdida de peso. Conclusión: El entrenamiento HIIT es más efectivo, tanto en tiempo como en resistencia a la adherencia. Tiene un buen efecto de mejora de la función cardiopulmonar, con un fuerte impacto en la optimización del IGC. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Predictive value of pulse infusion index in the short-term prognosis of patients with sepsis-induced acute kidney injury / 中华危重病急救医学

OBJECTIVE@#To investigate the predictive value of pulse infusion index (PPI) in the short-term prognosis of patients with sepsis-induced acute kidney injury (AKI).@*METHODS@#A retrospective cohort study was conducted. The clinical data of patients with sepsis-induced AKI admitted to intensive care unit (ICU) of the First Affiliated Hospital of Soochow University from July 2021 to December 2022 were enrolled. The basic information of the patients were collect, including age, gender, site of infection, underlying disease, mean arterial pressure (MAP) and heart rate (HR) at admission, as well as the use of mechanical ventilation and vasoactive drugs, and norepinephrine (NE) dosage. Laboratory indicators, sequential organ failure assessment (SOFA) score and PPI within 24 hours of admission were also recorded, and the patient's prognosis during ICU hospitalization was also recorded. The differences in clinical data between the patients of two groups with different prognosis were compared. Spearman correlation method was used to analyze the correlation between PPI and SOFA score. Binary multivariate Logistic regression analysis was used to screen independent risk factors for death during ICU hospitalization in sepsis patients with AKI. Receiver operator characteristic curve (ROC curve) was plotted to evaluate the predictive value of PPI for the short-term prognosis of patients with sepsis-induced AKI.@*RESULTS@#A total of 102 patients with sepsis-induced AKI were enrolled, of which 70 patients in the survival group and 32 patients in the death group, with ICU mortality of 31.4. Compared with the survival group, SOFA score, HR, procalcitonin (PCT), serum creatinine (SCr), and NE dosage in the death group were significantly increased [SOFA score: 11.22±2.48 vs. 8.56±2.01, HR (bpm): 103.80±12.47 vs. 97.41±9.73, PCT (μg/L): 9.22 (5.24, 17.84) vs. 6.19 (3.86, 7.71), SCr (μmol/L): 163.2 (104.7, 307.9) vs. 125.5 (89.3, 221.0), Lac (mmol/L): 2.81 (1.95, 4.22) vs. 2.13 (1.74, 2.89), NE usage (μg×kg-1×min-1): 0.7 (0.4, 1.1) vs. 0.5 (0.2, 0.6), all P < 0.05], while PPI was significantly lower than that in survival group [0.83 (0.42, 1.55) vs. 1.70 (1.14, 2.20), P < 0.01]. Spearman correlation analysis showed that based on SOFA score, PPI was closely related to the severity of patients with sepsis-induced AKI (r = -0.328, P < 0.05). Binary multivariate Logistic regression analysis showed that PPI [odds ratio (OR) = 0.590, 95% confidence interval (95%CI) was 0.361-0.966, P = 0.002], SOFA score (OR = 1.406, 95%CI was 1.280-1.545, P < 0.001), PCT (OR = 2.061, 95%CI was 1.267-3.350, P = 0.006) were independent risk factors of the short-term prognosis of patients with sepsis-induced AKI. ROC curve analysis showed that the area under the ROC curve (AUC) of PPI for death during ICU hospitalization in patients with sepsis-induced AKI was 0.779 (95%CI was 0.686-0.855, P < 0.001), which superior to PCT (AUC = 0.677, 95%CI was 0.577-0.766, P = 0.004), and similar to SOFA score (AUC = 0.794, 95%CI was 0.703-0.868, P < 0.001). When the cut-off value of PPI was 0.72, the sensitivity was 50.0%, and the specificity was 97.1%.@*CONCLUSIONS@#PPI has a good predictive value for the short-term prognosis of patients with sepsis-induced AKI during ICU hospitalization.

From Lung to Brain: Respiration Modulates Neural and Mental Activity / 神经科学通报·英文版

Respiration protocols have been developed to manipulate mental states, including their use for therapeutic purposes. In this systematic review, we discuss evidence that respiration may play a fundamental role in coordinating neural activity, behavior, and emotion. The main findings are: (1) respiration affects the neural activity of a wide variety of regions in the brain; (2) respiration modulates different frequency ranges in the brain's dynamics; (3) different respiration protocols (spontaneous, hyperventilation, slow or resonance respiration) yield different neural and mental effects; and (4) the effects of respiration on the brain are related to concurrent modulation of biochemical (oxygen delivery, pH) and physiological (cerebral blood flow, heart rate variability) variables. We conclude that respiration may be an integral rhythm of the brain's neural activity. This provides an intimate connection of respiration with neuro-mental features like emotion. A respiratory-neuro-mental connection holds the promise for a brain-based therapeutic usage of respiration in mental disorders.

Research Progress in Physiological Evaluation and Treatment of Visually Induced Motion Sickness in Virtual Reality / 中国医学科学院学报

Visually induced motion sickness(VIMS)is the major barrier to be broken in the development of virtual reality(VR)technology,which seriously affects the progress in the VR industry.Therefore,the detection and evaluation of VIMS has become a hot research topic nowadays.We review the progress in physiological assessment of VIMS in VR based on several physiological indicators,including electroencephalogram(EEG),postural sway,eye movements,heart rate variability,and skin electrical signals,and summarize the available therapies,aiming to provide an outlook on the future research directions of VIMS.

Effects of moxibustion of "biaoben acupoint combination" on heart rate variability, atrial natriuretic peptide in the model rats of IBS-D complicated with anxiety / 中国针灸

OBJECTIVE@#To compare the effects on the heart rate variability (HRV) and the expression of the atrial natriuretic peptide (ANP) in the model rats of irritable bowel syndrome with predominant diarrhea (IBS-D) rats complicated with anxiety between moxibustion of "biaoben acupoint combination" and that of "conventional acupoint combination".@*METHODS@#Of 50 healthy SPF female SD rats, aged 3 months, 8 rats were selected randomly as a blank group, and the rest rats were prepared to be the model of IBS-D complicated with anxiety. Twenty-four rats after successfully modeled were randomized into a model group, a conventional acupoint combination group (convention group) and a biaoben acupoint combination group (biaoben group), 8 rats in each one. In the convention group, moxibustion was delivered at "Tianshu" (ST 25), "Zusanli"(ST 36) and "Shangjuxu"(ST 37); and in the biaoben group, moxibustion was applied to "Neiguan" (PC 6), "Zusanli" (ST 36), and "Guanyuan" (CV 4). One session of moxibustion took 20 min, once daily, for 14 days in total. Before and after intervention, the body mass and fecal moisture content were compared in the rats of each group; using abdominal wall withdrawal reflex, the visceral hypersensitivity was evaluated; with elevated plus maze (EPM) and light-dark box (LDB), the anxiety conditions were assessed. After intervention, HRV was compared among groups, the ultrastructure of intestinal mucosa was observed under the transmission electron microscope in the rats of each group, and ANP expression in the myocardial tissue was detected using Western blot method and immunofluorescence.@*RESULTS@#Before the intervention, compared with the blank group, the body mass and visceral pain threshold of rats were reduced in the model group, the convention group and the biaoben group (P<0.05), fecal moisture content and AWR scores (at the dilatation pressure of 40, 60 and 80 mm Hg, 1 mm Hg ≈ 0.133 kPa) were elevated (P<0.05); and time in the open arm, the open arm entry number and the total movement distance (EPM), the time spent in the light compartment, the number of dark to light transitions and the total transition distance (LDB) were decreased (P<0.05). After the intervention, compared with the blank group, in the model group, the body mass, visceral pain threshold, standard diviation of NN intervals (SDNN) and root mean square of successive RR interval differences (RMSSD) were dropped (P<0.05), fecal moisture content, AWR scores (the dilation pressures of 40, 60 and 80 mm Hg), LF/HF and ANP expression were increased (P<0.05), the time in open arm, the open arm entry number and the total movement distance (EPM), the time spent in the light compartment, the number of dark to light transitions and the total transition distance (LDB) were decreased (P<0.05). When compared with the model group, in the convention group and the biaoben group, the body mass, visceral pain threshold, SDNN and RMSSD were increased (P<0.05), fecal moisture content, AWR scores (the dilation pressures of 60 and 80 mm Hg), LF/HF and ANP expression were dropped (P<0.05), the time in open arm, the open arm entry number and the total movement distance (EPM), the time spent in the light compartment, the number of dark to light transitions and the total transition distance (LDB) were increased (P<0.05). In the biaoben group, compared with the convention group, the body mass, visceral pain threshold, SDNN and RMSSD were elevated (P<0.05), fecal moisture content, AWR score (the dilation pressure of 80 mm Hg), LF/HF and ANP expression were decreased (P<0.05), the time in open arm, the open arm entry number and the total movement distance (EPM), the time spent in the light compartment, the number of dark to light transitions and the total transition distance (LDB) were increased (P<0.05). The epithelial cells of the intestinal mucosa showed a normal morphology in the blank group, the tight junction of the cells was disrupted and the junction was loose in the model group; the tight junction was imperfect in the convention group, but it was intact in the biaoben group.@*CONCLUSION@#Compared with the conventional acupoint combination, moxibustion of biaoben acupoint combination is more effective on the symptoms of IBS-D complicated with anxiety in the model rats. The effect mechanism may be related to attenuating anxiety-like negative emotions, positively regulating HRV, stabilizing IBS-D intestinal mucosal barrier and down-regulating the expression of ANP in myocardium.

Theory and application of pulse diagnosis at Renying and Cunkou regions / 中国针灸

Renying and Cunkou pulse diagnostic method is one of the important parts of the pulse diagnosis in Huangdi Neijing (Inner Canon of Yellow Emperor) and has been controversial since its proposal. This article takes WANG Shu-he's diagnostic operation as the evidence, and is in reference of the statement, "Cun region (the region ahead of Guan region of Cunkou) determines the human life, that on the left hand refers to Renying, while on the right hand is Qikou". The pulse conditions on the left and right hands represent yin and yang. If Renying pulse on the left is greater, the diseases are in yang meridians, while if Cunkou pulse on the right is bustling, the diseases are in yin meridians. By comparing the pulse condition and strength, as well as the pulse beating (rapid and urgent) between Guan region and region ahead of Guan on the same side, the conditions of three yang and three yin meridians are detected. In treatment, based on the records of Renying and Cunkou pulse diagnosis in Huangdi Neijing, the principles are proposed for reinforcing and reducing methods on hand and foot meridians of yin and yang. Five-shu points and yuan-source points are taken as the main acupoints in acupuncture treatment. During treatment, the changes in pulse conditions should be emphasized specifically and those at Renying and Cunkou regions are the criteria for judging qi arrival and qi regulation.

Associations between indoor volatile organic compounds and nocturnal heart rate variability of young female adults: A panel study / 北京大学学报(医学版)

OBJECTIVE@#To investigate the association between short-term exposure to indoor total volatile organic compounds (TVOC) and nocturnal heart rate variability (HRV) among young female adults.@*METHODS@#This panel study recruited 50 young females from one university in Beijing, China from December 2021 to April 2022. All the participants underwent two sequential visits. During each visit, real time indoor TVOC concentration was monitored using an indoor air quality detector. The real time levels of indoor temperature, relative humidity, noise, carbon dioxide and fine particulate matter were monitored using a temperature and humidity meter, a noise meter, a carbon dioxide meter and a particulate counter, respectively. HRV parameters were measured using a 12-lead Holter. Mixed-effects models were used to evaluate the association between the TVOC and HRV parameters and establish the exposure-response relationships, and two-pollutant models were applied to examine the robustness of the results.@*RESULTS@#The mean age of the 50 female subjects was (22.5±2.3) years, and the mean body mass index was (20.4±1.9) kg/m2. During this study, the median (interquartile range) of indoor TVOC concentrations was 0.069 (0.046) mg/m3, the median (interquartile range) of indoor temperature, relative humidity, carbon dioxide concentration, noise level and fine particulate matter concentration were 24.3 (2.7) ℃, 38.5% (15.0%), 0.1% (0.1%), 52.7 (5.8) dB(A) and 10.3 (21.5) μg/m3, respectively. Short-term exposure to indoor TVOC was associated with significant changes in time-domain and frequency-domain HRV parameters, and the exposure metric for most HRV parameters with the most significant changes was 1 h-moving average. Along with a 0.01 mg/m3 increment in 1 h-moving average concentration of indoor TVOC, this study observed decreases of 1.89% (95%CI: -2.28%, -1.50%) in standard deviation of all normal to normal intervals (SDNN), 1.92% (95%CI: -2.32%, -1.51%) in standard deviation of average normal to normal intervals (SDANN), 0.64% (95%CI: -1.13%, -0.14%) in percentage of adjacent NN intervals differing by more than 50 ms (pNN50), 3.52% (95%CI: -4.30%, -2.74%) in total power (TP), 5.01% (95%CI: -6.21%, -3.79%) in very low frequency (VLF) power, and 4.36% (95%CI: -5.16%, -3.55%) in low frequency (LF) power. The exposure-response curves showed that indoor TVOC was negatively correlated with SDNN, SDANN, TP, and VLF when the concentration exceeded 0.1 mg/m3. The two-pollutant models indicated that the results were generally robust after controlling indoor noise and fine particulate matter.@*CONCLUSION@#Short-term exposure to indoor TVOC was associated with significant negative changes in nocturnal HRV of young women. This study provides an important scientific basis for relevant prevention and control measures.

Anesthesia Depth Monitoring Based on Anesthesia Monitor with the Help of Artificial Intelligence / 中国医疗器械杂志

OBJECTIVE@#To use the low-cost anesthesia monitor for realizing anesthesia depth monitoring, effectively assist anesthesiologists in diagnosis and reduce the cost of anesthesia operation.@*METHODS@#Propose a monitoring method of anesthesia depth based on artificial intelligence. The monitoring method is designed based on convolutional neural network (CNN) and long and short-term memory (LSTM) network. The input data of the model include electrocardiogram (ECG) and pulse wave photoplethysmography (PPG) recorded in the anesthesia monitor, as well as heart rate variability (HRV) calculated from ECG, The output of the model is in three states of anesthesia induction, anesthesia maintenance and anesthesia awakening.@*RESULTS@#The accuracy of anesthesia depth monitoring model under transfer learning is 94.1%, which is better than all comparison methods.@*CONCLUSIONS@#The accuracy of this study meets the needs of perioperative anesthesia depth monitoring and the study reduces the operation cost.

Design and implementation of a modular pulse wave preprocessing and analysis system based on a new detection algorithm / 生物医学工程学杂志

As one of the standard electrophysiological signals in the human body, the photoplethysmography contains detailed information about the blood microcirculation and has been commonly used in various medical scenarios, where the accurate detection of the pulse waveform and quantification of its morphological characteristics are essential steps. In this paper, a modular pulse wave preprocessing and analysis system is developed based on the principles of design patterns. The system designs each part of the preprocessing and analysis process as independent functional modules to be compatible and reusable. In addition, the detection process of the pulse waveform is improved, and a new waveform detection algorithm composed of screening-checking-deciding is proposed. It is verified that the algorithm has a practical design for each module, high accuracy of waveform recognition and high anti-interference capability. The modular pulse wave preprocessing and analysis software system developed in this paper can meet the individual preprocessing requirements for various pulse wave application studies under different platforms. The proposed novel algorithm with high accuracy also provides a new idea for the pulse wave analysis process.

Sulfur dioxide in the caudal ventrolateral medulla reduces blood pressure and heart rate in rats via the glutamate receptor and NOS/cGMP signal pathways / 生理学报

This study was designed to investigate the cardiovascular effects of sulfur dioxide (SO2) in the caudal ventrolateral medulla (CVLM) of anesthetized rats and its mechanism. Different doses of SO2 (2, 20, 200 pmol) or artificial cerebrospinal fluid (aCSF) were injected into the CVLM unilaterally or bilaterally, and the effects of SO2 on blood pressure and heart rate of rats were observed. In order to explore the possible mechanisms of SO2 in the CVLM, different signal pathway blockers were injected into the CVLM before the treatment with SO2 (20 pmol). The results showed that unilateral or bilateral microinjection of SO2 reduced blood pressure and heart rate in a dose-dependent manner (P < 0.01). Moreover, compared with unilateral injection of SO2 (2 pmol), bilateral injection of 2 pmol SO2 produced a greater reduction in blood pressure. Local pre-injection of the glutamate receptor blocker kynurenic acid (Kyn, 5 nmol) or soluble guanylate cyclase (sGC) inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 1 pmol) into the CVLM attenuated the inhibitory effects of SO2 on both blood pressure and heart rate. However, local pre-injection of nitric oxide synthase (NOS) inhibitor NG-Nitro-L-arginine methyl ester (L-NAME, 10 nmol) only attenuated the inhibitory effect of SO2 on heart rate but not blood pressure. In conclusion, SO2 in rat CVLM has cardiovascular inhibitory effects, and its mechanism is related to the glutamate receptor and NOS/cGMP signal pathways.

Development of a Multi-parameter Pulmonary Function Test System / 中国医疗器械杂志

To comprehensively evaluate the human body's respiratory, circular metabolism and other functions, and to diagnose lung disease, an accurate and reliable pulmonary function test (PFT) is developed. The system is divided into two parts:hardware and software. It realizes the collection of respiratory, pulse oxygen, carbon dioxide, oxygen and other signals, and draws flow-volume curve (FV curve), volume-time curve (VT curve), respiratory waveform, pulse wave, carbon dioxide and oxygen waveform in real time on the upper computer of the PFT system, and conducts signal processing and parameter calculation for each signal. The experimental results prove that the system is safe and reliable, it can accurately measure the basic functions of human body, and provide reliable parameters, and has good application prospects.

An Atrial Fibrillation Classification Method Study Based on BP Neural Network and SVM / 中国医疗器械杂志

Atrial fibrillation is a common arrhythmia, and its diagnosis is interfered by many factors. In order to achieve applicability in diagnosis and improve the level of automatic analysis of atrial fibrillation to the level of experts, the automatic detection of atrial fibrillation is very important. This study proposes an automatic detection algorithm for atrial fibrillation based on BP neural network (back propagation network) and support vector machine (SVM). The electrocardiogram (ECG) segments in the MIT-BIH atrial fibrillation database are divided into 10, 32, 64, and 128 heartbeats, respectively, and the Lorentz value, Shannon entropy, K-S test value and exponential moving average value are calculated. These four characteristic parameters are used as the input of SVM and BP neural network for classification and testing, and the label given by experts in the MIT-BIH atrial fibrillation database is used as the reference output. Among them, the use of atrial fibrillation in the MIT-BIH database, the first 18 cases of data are used as the training set, and the last 7 cases of data are used as the test set. The results show that the accuracy rate of 92% is obtained in the classification of 10 heartbeats, and the accuracy rate of 98% is obtained in the latter three categories. The sensitivity and specificity are both above 97.7%, which has certain applicability. Further validation and improvement in clinical ECG data will be done in next study.