A Light Adaptive Heart Rate Detection Method Based on Webcam / 中国医疗器械杂志

In order to extract the pulse wave signal of blood volume effectively in the case of uneven light, a light-adaptive heart rate detection method based on webcam was proposed. In this method, adaptive gamma transform is applied to face image sequence to eliminate the influence of illumination. The pulse wave source signal was extracted from the forehead area and the blood volume pulse wave was obtained by wavelet filtering. The heart rate is estimated by Fourier transform analysis. The Bland-Altman analysis indicates that the method used in this paper is in good agreement with the measurement results of the electronic sphygmomanometer, and the adaptive gamma transformation used in this paper eliminates the influence of light interference, and the measurement error of heart rate is significantly reduced, which is completely able to meet the requirements of daily heart rate monitoring.

Validity and Acceptability of Image-based Food Record in Assessing Nutrient Intake among selected Malaysian Undergraduates

@#Introduction: Recognising the limitations of present dietary assessments method, recent attention had been drawn to image-based food record (IBFR) to assess dietary intake of the population. Thus, the present study aimed to compare nutrient intake assessed using IBFR with 24-hour diet recall (24DR) among nutrition and dietetics student. Method: There were 46 nutrition and dietetic undergraduates participated in the study, and information on the socio-demographic background and acceptability toward IBFR were obtained. Respondents were trained to complete one-day IBFR, and they were interviewed by researchers on the following day for their 24DR. Result: The mean age of respondents was 21.4±1.7 years old. The present study revealed that there were significantly higher protein and beta-carotene, but lower vitamin C reported by IBFR compared to 24DR. Medium to strong correlations were found between IBFR and 24DR for energy and nutrients intakes. The Bland-Altman analysis demonstrated a good level of agreement between IBFR and 24DR for energy and macronutrients (carbohydrates, protein and fat), respectively. The mean differences between IBFR and 24DR were -36 kcal for total daily energy intake, while mean differences of -12.24g, 0.79g, and 1.52g were reported for carbohydrates protein, and fat, respectively. Moderate level of agreement toward acceptability was demonstrated, and most of them (67.4%) preferred IBFR method. Conclusion: The present study revealed that IBFR showed a good level of agreement with 24DR in assessing nutrient intake. However, more extensive works should be considered to improve IBFR in assessing the energy and nutrients intake for the general population.

Study on Respiratory Rate Monitoring Method Based on Breath Sounds / 中国医疗器械杂志

The article aims to discuss the feasibility of using respiratory sounds to monitor respiratory rate. The average power of respiratory sounds was created firstly, the autocorrelation algorithm was used to calculate the respiratory cycle. The respiratory cycle of nasal flow pressure signal was calculated simultaneously, and the result was taken as a reference standard, then, two groups of respiratory cycle data were analyzed by correlation analysis and Bland-Altman analysis. The respiratory rate is relatively stable, using respiratory sounds monitor respiratory rate is feasible, the respiratory rate changes obviously, the existing methods and algorithm using respiratory sounds are temporarily unable to accurately reflect the changes of respiratory rate, further research is needed.

Association between pulse pressure variation of radial artery and pulse pressure variation of dorsal pedal artery in neurosurgery operation / 临床麻醉学杂志

Objective To discuss the agreement between pulse pressure variation of radial artery and pulse pressure variation of dorsal pedalartery in neurosurgery.Methods Twenty-five patients undergoing selective craniotomy under general anesthesia were enrolled.The following data were monitored and recorded respectively after tracheal intubation general anesthesia under different time:radial artery pulse pressure variability (PPV1) and dorsalis pedis pulse pressure variation (PPV2).Tidal volume was set to 8 ml/kg.Bland-Altman plots were created to assess agreement between PPV1 and PPV2.Results The mean differences and the limits of agreement between PPV1 and PPV2 are 20 min after induction of anesthesia 0.5% (-1.9%-2.8%), boneless flap instantly-0.5% (-3.8%-2.9%), Cut the dura mater instantly-0.1% (-3.2%-3.0%), and bone flap 0.1% (-2.4%-2.6%).Conclusion Dorsal pedal artery pulse pressure variation in neurosurgery craniotomy has certain guiding significance to the monitoring and management.

Calorimetria indireta na monitoração hemodinâmica e metabólica em cães sob diferentes situações hemodinâmicas / Indirect calorimetry in hemodinamic and metabolic monitoring in dogs under different hemodynamic states

A monitoração do estado hemodinâmico visa ao equilíbrio entre a oferta e a demanda de oxigênio tecidual. O objetivo deste estudo foi avaliar a utilização da calorimetria indireta (CI) frente à termodiluição (TD) em cães sob diferentes estados hemodinâmicos. Utilizaram-se nove cães pesando 19,6±1,3kg, os quais foram anestesiados com isofluorano a 1,4V% (Basal), submetidos à ventilação mecânica (VM) e estados hipodinâmico (Hipo), com isofluorano a 3,5V%, e hiperdinâmico (Hiper), com dobutamina a 5µg/kg/min. Utilizou-se um cateter de Swan-Ganz para aferição do índice cardíaco (IC) por TD, cálculo do consumo de oxigênio pelo método de Fick (VO2Fick) e para coleta de sangue venoso central e misto. Com a CI, obtiveram-se os valores de consumo de oxigênio (VO2), produção de CO2(VCO2) e expirado de CO2 (EtCO2). Para a determinação do IC por CI, utilizou-se o princípio de Fick com os valores de VO2 e os sangues arteriais e venosos misto (Fickmix) ou central (Fickvc), e pela relação dos valores de VCO2 e EtCO2(FickCO2). A análise estatística compreendeu os testes de Dunnet, para diferença entre as fases, e Tukey, para diferenças entre os métodos (P≤0,05). Foram realizadas as análises de correlação de Pearson e de concordância de Bland-Altman. A CI forneceu valores de VO230 a 40% maiores que VO2Fick, mas identificou a redução no VO2 após a VM e Hipo, o que não ocorreu com VO2Fick. Os valores de VCO2diminuíram nas fases VM e Hipo. Houve redução do IC na fase Hipo com todos os métodos e aumento na fase Hiper com TD e Fickvc. Os valores de IC pelos métodos de Fickmixe Fickvc foram maiores que TD em todos os momentos, e FickCO2foi menor que TD na fase Hiper. Nenhum dos métodos apresentou concordância e correlação com a TD. Conclui-se que a CI pode ser utilizada na mensuração do VO2 e VCO2 de cães sob diferentes estados hemodinâmicos. Contudo, embora seja possível a identificação dos diferentes estados hemodinâmicos, os valores de IC não podem ser comparados à termodiluição.

Monitoring the hemodynamic state seeks a balance between the supply and demand of oxygen by tissues. The aim of this study was to evaluate the use of indirect calorimetry (IC) compared to thermodilution (TD) in dogs under different hemodynamic states. Nine dogs weighing 19.6±1.3kg were anesthetized with isoflurane at 1.4 V% (Baseline) and subjected to mechanical ventilation (MV), a hypodynamic state (Hypo) with isoflurane at 3.5V% and hyperdynamic state (Hyper) with dobutamine infusion at 5μg/kg/min. We used a Swan-Ganz catheter for measurement of cardiac index (CI) by TD, calculation of oxygen consumption by Fick's method (VO2Fick) and to collect central and mixed venous blood. With the IC we obtained oxygen consumption (VO2), CO2 production (VCO2) and end tidal CO2(EtCO2). For the determination of CI by IC we used the Fick's principle with VO2values, and arterial and mixed venous blood (Fickmix)or arterial and central venous blood (Fickvc); and by the ratio of the values of VCO2 and EtCO2(FickCO2). We performed the statistical analysis by Dunnet tests, for the difference between the states, and Tukey for differences between methods (P≤0.05). Pearson correlation and Bland-Altman analysis was performed for correlation and agreement analysis. IC provided VO2values 30 to 40% higher than the VO2Fick but identified the reduction in VO2after VM and Hypo, which did not occur with VO2Fick. The VCO2 values decreased in VM and Hypo. CI values decreased in Hypo with all methods and increase in Hyper with TD and Fickvc. The CI values for Fickmix and Fickvc were greater than TD at all times and FickCO2 was lower than TD in the Hyper. None of the methods presented agreement and correlation with TD. Thus, indirect calorimetry can be used to measure the VO2 and VCO2 in dogs in different hemodynamic states. However, although it is possible to identify the hemodynamic status, cardiac index values cannot be compared to thermodilution.

Assessment of Blood Glucose Values Measured by Blood Gas Analyzer or Portable Glucometer / 대한마취과학회지

BACKGROUND: A portable glucometer is commonly used to immediately check the blood glucose level. In the anesthetic field, some blood gas analyzers can also give a rapid indication of the blood sugar level but the accuracy is unknown. Therefore, this study assessed the accuracy of the blood glucose values measured by either a blood gas analyzer or portable glucometer. METHODS: Venous blood from diabetic patients was used to measure the glucose level with either a blood gas analyzer or a portable glucometer. The difference and 5% deviation from reference values was analyzed. These values were also assessed using a Bland-Altman plot and clinical significance was examined using a Clarke error grid. RESULTS: The differences from the reference values were smaller using the blood gas analyzer (1.3 +/- 7.8 mg/dl) than using the portable glucometer (-5.1 +/- 16.7 mg/dl)(P < 0.01). 73.4% of the values measured by the blood gas analyzer and 40.0% of those measured by the portable glucometer were within 5% of the reference value. The 95% limits of agreement in the difference ranged from -14.3 to 16.9 in the blood gas analyzer and -38.5 to 28.2 in the portable glucometer. Error grid analysis showed that 100% of the values measured by the blood gas analyzer were located in zone A. When locating the values measured using the portable glucometer, 95.6% were located in zone A, and the remaining 4.4% are located in zone B. CONCLUSIONS: The blood gas analyzer measures the blood glucose more accurately than the portable glucometer. However, the blood glucose values measured by the portable glucometer are clinically acceptable.