Using radial pulse wave as hemodynamic measurements to quantify effects of acupuncture therapy for patients with traumatic brain injury and ischemia stroke.

Background and aim: Traumatic Brain Injury (TBI) and stroke are major sources of death and disability worldwide. Acupuncture has been used as a supplemental therapy for patients with TBI and stroke. This study was aimed to evaluate the effects of acupuncture therapy for patients with TBI and stroke by radial pulse spectrum. Experimental procedure: 22 patients (6 TBI and 16 stroke) were enrolled and underwent radial pressure wave measurement before and after acupuncture treatment at Dubi (ST-35), Zusanli (ST-36) and Jiexi (ST-41). The harmonic analysis of the radial pressure wave was calculated and transformed into Fourier series coefficients Cn, Pn and the variation coefficient CnCV. Results: After acupuncture, systolic blood pressure, heart rate, and Glasgow Coma Scale changed very slightly. The harmonic index C4, C7, C9, C10, C3CV and C5CV had significant increases. (P < 0.05) After 3-week course acupuncture treatment, systolic blood pressure, C7, C8, C9, C10 and P10 had significant increases. (P < 0.05). Conclusion: Harmonic analysis of radial pulse waves may detect earlier circulatory system changes of acupuncture treatment before they were evident with other hemodynamic readings or scale.

A non-invasive harmonic analysis to assess risk of retinopathy in type 2 diabetes mellitus.

AIMS: Assessing the hemodynamic changes of diabetic retinopathy (DR) using harmonic analysis of both non-invasively measured radial pulse and photoplethysmography (PPG) signals to propose a DR risk indicator. METHODS: A total of 1879 patients with diabetes were followed on average of 3.5 years. The radial pulse and PPG signals were measured at the beginning of the trial. Kaplan-Meier curves of the DR risk indicator was analyzed. In addition, the correlation between the measurements of the radial pulse and PPG was evaluated. RESULTS: In comparison of the patients' clinical characteristics, years of diabetes, systolic blood pressure, HbA1C, ACR, urinary albumin and fourth harmonic (C4) were higher in the DR group, and eGFR and third harmonic (C3) were lower. Patients in the high-DR risk group had a 1.8-fold higher risk of developing retinopathy than those in the low-risk group (log-rank test, p < 0.001). The correlation coefficient between radial pulse and PPG measurements for C3 and C4 were 0.727 and 0.628, respectively. CONCLUSIONS: The harmonic analysis of radial pulse and PPG signals may be used to reflect the effect of DR in hemodynamics and the derived harmonic components may predict the risk of DR of patients with type 2 diabetes.

Non-Invasive radial pressure wave analysis may digitally predict women's risks of type 2 diabetes (T2DM): A case and control group study.

BACKGROUND: Women not only have worse diabetes complications, but also have menstrual cycle, pregnancy, and menopause which can make managing diabetes more difficult. The aim of this study was to investigate if radial pressure wave analysis may non-invasively screen for women's risk of type 2 diabetes. METHODS: Spectrum analysis of the radial pressure wave was performed to evaluate the first five harmonic components, C1 to C5. The study consisted of a total of 808 non-pregnant female subjects aged 20-95 over the period of 4 years, and 404 of them were diagnosed with Type 2 diabetes as the case group. RESULT: The first five harmonic components are significantly different in a comparison of the case group and the control group. In the logistic regression analysis, T2DM was found to be associated with C1 (OR = 1.055, CI = 1.037-1.074, p < 0.001), C2 (OR = 1.051, CI = 1.019-1.085, p = 0.002), and C3 (OR = 0.972, CI = 0.950-0.994, p = 0.013). In the Receiver Operating Characteristic curve analysis, the Area Under Curve of using C3 only (70%, p <0.05), weighted C1, C2 and C3, (75%, p < 0.05), and weighted C1, C2 and C3 and Body mass Index (84%, p <0.05) were tested for the accuracy on how well these tests separate the women into the groups with and without the T2DM. CONCLUSION: We thus concluded that pulse spectrum was a non-invasive predictor for women's risk of T2DM.

Noninvasively measured radial pressure wave analysis provides insight into cardiovascular changes during pregnancy and menopause.

OBJECTIVE: Pregnancy and menopause are significant life events associated with major changes in female hormone levels and changes in cardiovascular health. The role of estrogen in influencing cardiovascular risk is an ongoing research topic. Many studies have provided evidence that radial pressure wave characteristics are an important indicator to consistently and independently predict cardiovascular events. The aim of this study was to investigate if radial pressure wave analysis provided statistical insights into the physiological variations due to pregnancy and menopause. Furthermore, the study investigated how these variations could serve as an indicator for cardiovascular risks. As the radial pulse measurement is non-invasive and speedy, it may be helpful in evaluating cardiovascular changes and risk during these transitions. MATERIALS AND METHOD: A total of 702 randomly selected female subjects (90 pregnant and 97 post-menopausal), aged 20-59, enrolled in the study. The visit measured the subject's hemodynamic parameters including heart rate, systolic blood pressure (SBP), diastolic blood pressure (DBP) and radial pressure waves. SBP and DBP were evaluated by an automatic blood pressure monitor. Radial pressure wave data were continuously recorded for 12-s using a TD01C pulse measuring instrument. Spectrum analysis of the radial pressure wave was performed to evaluate the first five harmonic components (C1-C5). RESULTS: A comparison of pregnant women to non-pregnant women showed C3 and C5 were lower. Heart rate C2 and C4 were higher in pregnant women. A comparison of women pre-menopausal and post-menopausal showed no significant difference in SBP or DBP. Menopause significantly changed the C1 and C4 radial pressure wave harmonics. An increase in C1 and a decrease in C4 were observed. CONCLUSION AND DISCUSSION: This study provided further clinical evidence to support the hemodynamic model that describes the cardiovascular changes and risks related to the harmonic components of the pulse spectrum. Beyond blood pressure, the effects of menopause on the radial pressure wave, especially on hemodynamic index C4, independent of age and BMI, may explain increased post-menopausal cardiovascular risk. This and past studies collectively suggest that radial pressure wave components may be an indicator of a female body's ability to supply oxygen and nutrients. Harmonic analysis of the radial pressure wave may provide additional insights into the underlying mechanism of the cardiovascular changes over the lifespan of a woman.

Risk assessment of macrovascular and microvascular events in patients with type 2 diabetes by analyzing the amplitude variation of the fourth harmonic component of radial pulse wave.

This investigation explored the hypothesis that whether the coefficient of variation of the fourth harmonic amplitude of the radial pulse wave (C4CV) predicts the risk of macrovascular and microvascular events in patients with type 2 diabetes mellitus (T2DM). Radial pulse wave and brachial blood pressure were measured at baseline in 2324 patients with T2DM and C4CV was calculated using the Fourier series method. Macrovascular and microvascular events during follow-up were determined by medical records. We plotted the Kaplan-Meier curve and performed a Cox proportional hazard model and a log-rank test to estimate the effectiveness of C4CV as a risk predictor. We divided patients into quartile groups based on C4CV (<4.3%, 4.3% to 6.8%, 6.8% to 11.4%, and >11.4%). Compared with patients with C4CV < 4.3%, patients with C4CV> 11.4% had a double incidence of macrovascular events (hazard ratio, 2.13; 95% CI, 1.70-2.67) and microvascular events (hazard ratio, 2.08; 95% CI, 1.67-2.58), and the incidence of cardiovascular death was three times (hazard ratio, 3.03; 95% CI, 1.10-8.83). The Cox regression analysis demonstrated that the risk of both macrovascular and microvascular outcomes increases with the increase in quartile level of C4CV value (P < 0.0001). These associations remained after adjustment for age, gender, smoking, systolic blood pressure, diastolic blood pressure, dyslipidemia, diabetes duration, Hba1c, and cardiovascular disease (P < 0.0001). C4CV is a novel independent predictor of cardiovascular mortality, macrovascular events, and microvascular events in patients with T2DM.

The first harmonic of radial pulse wave predicts major adverse cardiovascular and microvascular events in patients with type 2 diabetes.

This brief report take a further look on the first harmonic of radial pulse wave (C1) after the 1.8 ±â€¯0.5 years follow-up and demonstrated that the quartile level of C1 independently predicts the risk of cardiovascular death, major adverse cardiovascular events, and microvascular outcomes in 2324 patients with type 2 diabetes.

Fourth harmonic of radial pulse wave predicts adverse cardiac events in asymptomatic patients with type 2 diabetes.

AIMS: Studies have shown that the fourth harmonic of the radial pulse wave (C4) is associated with atherosclerotic processes and myocardial ischemia. We sought to investigate whether C4 is an independent predictor of adverse cardiac events (ACE). METHODS: The baseline C4 is calculated using the Fourier series method. 1968 asymptomatic patients with type 2 diabetes were followed up for 1.8 ±â€¯0.4 years and survival analysis were performed using Cox proportional hazard model. RESULTS: The Cox regression analysis showed that the C4 value is independent and inversely related to ACE both before and after adjusting for age, sex, smoke, systolic blood pressure, dyslipidemia, and Hba1c. (P for trend < 0.001) CONCLUSIONS: Decreasing C4 is associated with an increased risk of ACE in asymptomatic patients with type 2 diabetes.

Effect of Black Tea and Green Tea on the Radial Pulse Spectrum in Healthy Humans.

The consumption of black tea and green tea has been shown to be beneficial for cardiovascular health. Because the chemical composition of the two teas varies widely, the purpose of the study was to investigate whether the consumption of green tea and black tea had different effects on the arterial system. Thirty-three healthy subjects received a single dose of green tea (dose = 0.05 g/kg) and black tea (dose = 0.05 g/kg) in different weeks. Radial blood pressure and radial pulse pressure were measured before and after drinking tea. The harmonic analysis was performed on radial pressure waves, and harmonics (Cns) were recorded. The results showed that both black tea and green tea consumption significantly increased the C1, C2, C6, C7, C8, C9, and C10 of the radial pressure wave. Furthermore, the results confirmed that the consumption effect of green tea on C6-C10 increase is greater than that of black tea. This report also found a subtle difference that consumption of green tea increased C4, whereas consumption of black tea increased C3. We concluded that black tea and green tea have similar patterns in higher harmonics, but with varying degrees.

The effect of radial pulse spectrum on the risk of major adverse cardiovascular events in patients with type 2 diabetes.

Radial pulse spectrum has been shown to correlate with coronary stenosis in patients with type 2 diabetes mellitus (T2DM). In academia, it has not been demonstrated that the radial artery pulse spectrum is an independent risk factor for major adverse cardiovascular events (MACE), including myocardial infarction, stroke, and all-cause mortality. The primary objective of this study is to assess the risk of MACE, in patients with T2DM and to determine if an increase in MACE would be associated with a first harmonic (C1) increase in the radial artery pulse. 1972 consecutive patients with T2DM were enrolled. All subjects received measurements of radial pulse waves at baseline. Harmonic analysis of radial pressure wave was performed. The hazard ratios for MACE and its 95% confident interval were estimated using Cox proportional hazard model. The follow-up period lasted for one year. MACE was detected in 232 (11.8%) of those with T2DM. The log-rank test demonstrated that the cumulative incidence of patients with C1 above 0.96 was greater than those with C1 bellow 0.96. Comparing the patients with C1 smaller than first quartile to the patients with C1 greater than third quartile, higher C1 increased the cardiovascular risks as follows: MACE (Hazard ratio,1.93; 95% CI,1.31-2.86), stroke (Hazard ratio, 1.61; 95% CI, 0.90-2.90), myocardial infarction (Hazard ratio, 2.23; 95% CI, 1.33-3.74). The risk for the composite MACE increased continuously as C1 increased (P < 0.001 for trend). The hazard ratio and trend for all-cause mortality were not significant. Increased C1 resulted in increased risk for nonfatal stroke, and nonfatal myocardial infarction among patients with T2DM. Our results indicate that the degree of C1 is a risk factor for nonfatal MACE. Therefore, the radial pulse spectrum could identify patients with T2DM at high risk of nonfatal MACE.

The First Harmonic of Radial Pulse as an Early Predictor of Silent Coronary Artery Disease and Adverse Cardiac Events in Type 2 Diabetic Patients.

BACKGROUND: It has been reported that harmonics of radial pulse is related to coronary artery disease (CAD) in patients with type 2 diabetes mellitus (T2DM). It is still unclear whether or not the first harmonics of the radial pulse spectrum is an early independent predictor of silent coronary artery disease (SCAD) and adverse cardiac events (ACE). OBJECTIVES: To measure the risk of SCAD in patients with T2DM and also to survey whether or not an increment of the first harmonic (C1) of the radial pulse increases ACE. METHODS: 1968 asymptomatic individuals with T2DM underwent radial pulse wave measurement. First harmonic of the radial pressure wave, C1, was calculated. Next, the new occurrence of ACE and the new symptoms and signs of coronary artery disease were recorded. The follow-up period lasted for 14.7 ± 3.5 months. RESULTS: Out of 1968 asymptomatic individuals with T2DM, ACE was detected in 239 (12%) of them during the follow-up period. The logrank test demonstrated that the cumulative incidence of ACE in patients with C1 above 0.96 was greater than that in those patients with C1 below 0.89 (P < 0.01). By comparing the data of patients with C1 smaller than the first quartile and the patients with C1 greater than the third quartile, the hazard ratios were listed as follows: ACE (hazard ratio, 2.29; 95% CI, 1.55-3.37), heart failure (hazard ratio, 2.22; 95% CI, 1.21-4.09), myocardial infarction (hazard ratio, 2.44; 95% CI, 1.51-3.93), left ventricular dysfunction (Hazard ratio, 2.01; 95% CI, 0.86-4.70), and new symptoms and signs for coronary artery disease (hazard ratio, 2.03; 95% CI, 1.45-2.84). As C1 increased, the risk for composite ACE (P < 0.001 for trend) and for coronary disease (P < 0.001 for trend) also increased. The hazard ratio and trend for cardiovascular-cause mortality were not significant. CONCLUSIONS: This study showed that C1 of the radial pulse wave is correlated with cardiovascular events. Survival analysis showed that C1 value is an independent predictor of ACE and SCAD in asymptomatic patients with T2DM. Thus, screening for the first harmonic of the radial pulse may improve the risk stratification of cardiac events and SCAD in asymptomatic patients although they had no history of coronary artery disease or angina-related symptom.

Radial Pulse Spectrum Analysis as Risk Markers to Improve the Risk Stratification of Silent Myocardial Ischemia in Type 2 Diabetic Patients.

Diabetic patients with silent myocardial ischemia (SMI) have elevated rates of morbidity and mortality and need intensive care and monitoring. An early predictor of SMI may lead to early diagnosis and medical treatment to prevent progression and adverse clinical events. Therefore, this paper was aimed to evaluate the radial pulse spectrum as risk markers to improve the risk stratification of SMI in type-2 diabetic patients; 195 diabetic patients at high-risk of SMI were enrolled. All patients underwent myocardial perfusion imaging and radial pressure wave measurement. The spectrum analysis of the radial pressure wave was calculated and transformed into Fourier series coefficients Cns and Pns. The risk of SMI (odds ratio: 4.46, 95%, C.I. 1.61-12.4, [Formula: see text]) was raised in diabetic patients classified high-risk group by C2. Multivariable regression analysis showed that C2 ([Formula: see text]) and ankle-brachial index [(ABI) [Formula: see text])] were related to SMI ([Formula: see text] and [Formula: see text]). The myocardial ischemic score (MIS), combining C2, C3, and P5, the albumin-to-creatinine ratio (ACR), and ABI, presented an excellent risk stratification performance in enrolled patients (odds ratio: 5.78, 95%, C.I. 2.29-14.6, [Formula: see text]). The area under receiver operating characteristic curves for C2, C3, P5, ABI, ACR, and MIS were 0.66, 0.60, 0.68, 0.51, 0.56, and 0.74, respectively, in identifying SMI. This paper demonstrated that C2 was independently associated with the extent of SMI in multivariable regression analysis. Odds ratio and chi-square tests reflected that C2 could be an important marker for the risk stratification of SMI. Furthermore, MIS, adding radial pulse spectrum analysis to ACR and ABI, could significantly improve the risk stratification of SMI in type-2 diabetic patients compared to any single risk factor.

A retrospective on the LBNL PEM project.

We present a retrospective on the LBNL Positron Emission Mammography (PEM) project, looking back on our design and experiences. The LBNL PEM camera utilizes detector modules that are capable of measuring depth of interaction (DOI) and places them into 4 detector banks in a rectangular geometry. In order to build this camera, we had to develop the DOI detector module, LSO etching, Lumirror-epoxy reflector for the LSO array (to achieve optimal DOI), photodiode array, custom IC, rigid-flex readout board, packaging, DOI calibration and reconstruction algorithms for the rectangular camera geometry. We will discuss the high-lights (good and bad) of these developments.

The eccentric position of the heart in the mammalian body and optimal energy transfer in single tube models.

Many phenomena cannot be explained by traditional haemodynamics models. For example, the hearts of all mammals are neither at one end of the circulatory system nor at the geometric centre. Based on a new circulation model, we report that if the heart is located at either of these two positions, the energy saving rule will be violated. We assume that the main arterial system is under a steady, distributed transverse vibration with the heart as the input power source. The equation of motion of the artery is governed by a new pressure wave equation with total energy. We analyse the effects of the heart position on the pressure pulse shape and the spectrum. By a simplifying T-tube model, we find that there are many harmonic oscillating modes for the overall arterial system. The position of the heart affects the weights of different modes. If the heart is at the midpoint or at one end of the body, none of the even harmonic modes can be excited. If the heart is at a third along the whole system, the third oscillation mode in the system is missing. Thus, from an efficiency point of view, this model gives a strong reason for all mammals' hearts being at an eccentric position. Tube simulations were carried out to confirm the theoretical prediction. A new standing wave model to analyse the variation of the pressure pulse shape along the artery is discussed. The interesting result indicates that our new pressure wave equation possesses a high problem solving potential. It provides a new tool for studying arterial dynamics.

Pressure pulse velocity is related to the longitudinal elastic properties of the artery.

It is known that arteries in their natural position are always subject to a longitudinal stress. However, the effect of this strong longitudinal tension has seldom been addressed. In this paper, we point out that the traditional pulse wave velocity formulae considering only the circumferential elasticity fail to include all the important energies. We present a vigorous derivation of a pressure wave equation, the pressure wave equation with total energy, which considers all the important energies of the whole arterial system by treating the arterial wall and the blood as one system. Our model proposes that the energy transport in the main arterial system is primarily via the transverse vibration motion of the elastic wall. The final equation indicates that the longitudinal stress is essential and the high frequency phase velocity is related to the longitudinal tension along the arterial wall and its Young's shearing modulus. By applying this equation, we suggest that longitudinal elastic property is an important factor in hemodynamics and in the treatment of cardiovascular diseases.