Cuffless and Continuous Blood Pressure Estimation from the Heart Sound Signals.

Cardiovascular disease, like hypertension, is one of the top killers of human life and early detection of cardiovascular disease is of great importance. However, traditional medical devices are often bulky and expensive, and unsuitable for home healthcare. In this paper, we proposed an easy and inexpensive technique to estimate continuous blood pressure from the heart sound signals acquired by the microphone of a smartphone. A cold-pressor experiment was performed in 32 healthy subjects, with a smartphone to acquire heart sound signals and with a commercial device to measure continuous blood pressure. The Fourier spectrum of the second heart sound and the blood pressure were regressed using a support vector machine, and the accuracy of the regression was evaluated using 10-fold cross-validation. Statistical analysis showed that the mean correlation coefficients between the predicted values from the regression model and the measured values from the commercial device were 0.707, 0.712, and 0.748 for systolic, diastolic, and mean blood pressure, respectively, and that the mean errors were less than 5 mmHg, with standard deviations less than 8 mmHg. These results suggest that this technique is of potential use for cuffless and continuous blood pressure monitoring and it has promising application in home healthcare services.

Efficacy and safety of apatinib plus docetaxel as the second or above line treatment in advanced nonsquamous NSCLC: A multi center prospective study.

BACKGROUND: Apatinib is an oral small-molecule tyrosine kinase inhibitor targeting vascular endothelial growth factor receptor 2 (VEGFR-2). Some clinical trials have demonstrated that apatinib is efficacious against advanced nonsquamous NSCLC. OBJECTIVE: This study aimed to probe efficacy and safety of apatinib plus docetaxel, as the second or above line treatment, in advanced nonsquamous NSCLC. DESIGN: Multicenter, prospective, single arm study. SETTING: Three teaching hospitals centers in the Sichuan. PARTICIPANTS: Fourteen patients with stage IVA/B nonsquamous NSCLC had previously received at least 1 platinum-based chemotherapy regimen. INTERVENTION: Patients who were enrolled between November 2016 and January 2018 were given docetaxel (75 mg/m, i.v., d1) plus oral apatinib (250 mg/d), 4 weeks as one cycle, until disease progression or intolerance to adverse events (AE). MAIN OUTCOME MEASURES: The primary endpoint was progression-free survival (PFS). The secondary endpoints comprised objective response rate (ORR), disease control rate (DCR), overall survival (OS), and AE incidence rate. RESULTS: All patients carried adenocarcinoma by pathological type. The median follow-up duration was 9.76 months. Out of 14 cases, 12 were evaluable, showing ORR of 33.33%, DCR of 66.67%, DCR of 50% in cases with brain metastasis, median PFS of 2.92 months (95% CI: 1.38-4.48), and 6-month OS of 80%. Primary AEs encompassed: leukopenia in 7 cases (58.33%), hand-foot skin reaction in 5 cases (41.67%), and diarrhea in 4 cases (33.33%). Among them, grade 3 AEs were: leukopenia in 4 cases (33.33%), and hand-foot skin reaction in 1 case (8.33%). No grade 4/5 AEs were reported. Univariate and multivariate analysis were conducted respectively for PFS and OS. These factors encompassed: gender, age, gene mutations, clinical stage, ECOG scores, quantity of metastatic foci, brain metastasis, and hand-foot skin reaction. Results demonstrated zero risk factors for PFS or OS. CONCLUSION: Apatinib plus docetaxel, as the second or above line treatment, is effective and safe against advanced nonsquamous NSCLC, with good tolerance profile. TRIAL REGISTRATION: NCT03416231.

Time-frequency analysis of heart rate variability during the cold pressor test using a time-varying autoregressive model.

Heart rate variability is a useful clinical tool for autonomic function assessment and cardiovascular disease diagnosis. To investigate the dynamic changes of sympathetic and parasympathetic activities during the cold pressor test, we used a time-varying autoregressive model for the time-frequency analysis of heart rate variability in 101 healthy subjects. We found that there were two sympathetic peaks (or two parasympathetic valleys) when the abrupt changes of temperature (ACT) occurred at the beginning and the end of the cold stimulus and that the sympathetic and parasympathetic activities returned to normal in about the last 2 min of the cold stimulus. These findings suggested that the ACT rather than the low temperature was the major cause of the sympathetic excitation and parasympathetic withdrawal. We also found that the onsets of the sympathetic peaks were 4-26 s prior to the ACT and the returns to normal were 54-57 s after the ACT, which could be interpreted as the feedforward and adaptation of the autonomic regulation process in the human body, respectively. These results might be helpful for understanding the regulatory mechanisms of the autonomic system and its effects on the cardiovascular system.

[The association of paraoxonase 2 gene C311S variant with ischemic stroke in Chinese type 2 diabetes mellitus patients].

OBJECTIVE: To investigate the association between the C311S polymorphism of paraoxonase 2 (PON2) gene and ischemic stroke in Chinese type 2 diabetes mellitus (T2DM) patients. METHODS: A case-control study of 279 Chinese subjects (including 162 T2DM with or without ischemic stroke and 117 non-diabetic control) was performed. Genotype frequencies of C311S polymorphism were studied by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) analysis with DdeI digestion. RESULTS: C311S polymorphism of PON2 gene was detected in Chinese with the C/S allele frequencies 0.145 and 0.855. The frequency distribution showed significant difference between Chinese and Asian Indian. Furthermore, the genotype distribution (SS, CS and CC) of the PON2 C311S gene polymorphism exhibited a significant difference between T2DM patients complicated with ischemic stroke and T2DM without ischemic stroke, the former had a significantly higher C allele frequency(P<0.05). CONCLUSION: The above data indicate that the polymorphism at codon 311(Cys --> Ser)in the PON2 gene is associated with ischemic morbidity in Chinese T2DM patients and C allele might be a risk factor.