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Hemodynamic profiles of arterial hypertension with ambulatory blood pressure monitoring. Hypertens Res 2023:10.1038/s41440-023-01196-z. [PMID: 36890272 DOI: 10.1038/s41440-023-01196-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 12/28/2022] [Accepted: 01/23/2023] [Indexed: 03/10/2023]
Abstract
Blood pressure (BP) measurements obtained during a twenty-four-hour ambulatory blood pressure monitoring (24 h ABPM) have not been reliably applied to extract arterial hemodynamics. We aimed to describe the hemodynamic profiles of different hypertension (HT) subtypes derived from a new method for total arterial compliance (Ct) estimation in a large group of individuals undergoing 24 h ABPM. A cross-sectional study was conducted, which included patients with suspected HT. Cardiac output, Ct, and total peripheral resistance (TPR) were derived through a two-element Windkessel model without having a pressure waveform. Arterial hemodynamics were analyzed according to HT subtypes in 7434 individuals (5523 untreated HT and 1950 normotensive controls [N]). The individuals mean age was 46.2 ± 13.0 years; 54.8% were male, and 22.1% were obese. In isolated diastolic hypertension (IDH), the cardiac index (CI) was greater than that in normotensive (N) controls (CI: IDH vs. N mean difference 0.10 L/m/m2; CI 95% 0.08 to 0.12; p value <0.001), with no significant clinical difference in Ct. Isolated systolic hypertension (ISH) and divergent systolic-diastolic hypertension (D-SDH) had lower Ct values than nondivergent HT subtype (Ct: divergent vs. nondivergent mean difference -0.20 mL/mmHg; CI 95% -0.21 to -0.19 mL/mmHg; p value <0.001). Additionally, D-SDH displayed the highest TPR (TPR: D-SDH vs. N mean difference 169.8 dyn*s/cm-5; CI 95% 149.3 to 190.3 dyn*s/cm-5; p value <0.001). A new method is provided for the simultaneous assessment of arterial hemodynamics with 24 h ABPM as a single diagnostic tool, which allows a comprehensive assessment of arterial function for hypertension subtypes. Main hemodynamic findings in arterial HT subtypes with regard to Ct and TPR. The 24 h ABPM profile reflects the state of Ct and TPR. Younger individuals with IDH present with a normal Ct and frequently increased CO. Patients with ND-SDH maintain an adequate Ct with a higher TPR, while subjects with D-SDH present with a reduced Ct, high PP and high TPR. Finally, the ISH subtype occurs in older individuals with significantly reduced Ct, high PP and a variable TPR proportional to the degree of arterial stiffness and MAP values. There was an observed increase in PP with age in relation to the changes in Ct (see also text). SBP: systolic blood pressure; DBP: diastolic blood pressure; MAP: mean arterial pressure; PP: pulse pressure; N: normotension; HT: hypertension; IDH: isolated diastolic hypertension; ND-SDH: nondivergent systole-diastolic hypertension; D-SDH: divergent systolic-diastolic hypertension; ISH: isolated systolic hypertension; Ct: total arterial compliance; TPR: total peripheral resistance; CO: cardiac output; 24 h ABPM: 24 h ambulatory blood pressure monitoring.
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Liu SH, Yang ZK, Pan KL, Zhu X, Chen W. Estimation of Left Ventricular Ejection Fraction Using Cardiovascular Hemodynamic Parameters and Pulse Morphological Characteristics with Machine Learning Algorithms. Nutrients 2022; 14:4051. [PMID: 36235703 PMCID: PMC9572754 DOI: 10.3390/nu14194051] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 09/22/2022] [Accepted: 09/26/2022] [Indexed: 11/16/2022] Open
Abstract
It is estimated that 360,000 patients have suffered from heart failure (HF) in Taiwan, mostly those over the age of 65 years, who need long-term medication and daily healthcare to reduce the risk of mortality. The left ventricular ejection fraction (LVEF) is an important index to diagnose the HF. The goal of this study is to estimate the LVEF using the cardiovascular hemodynamic parameters, morphological characteristics of pulse, and bodily information with two machine learning algorithms. Twenty patients with HF who have been treated for at least six to nine months participated in this study. The self-constructing neural fuzzy inference network (SoNFIN) and XGBoost regression models were used to estimate their LVEF. A total of 193 training samples and 118 test samples were obtained. The recursive feature elimination algorithm is used to choose the optimal parameter set. The results show that the estimating root-mean-square errors (ERMS) of SoNFIN and XGBoost are 6.9 ± 2.3% and 6.4 ± 2.4%, by comparing with echocardiography as the ground truth, respectively. The benefit of this study is that the LVEF could be measured by the non-medical image method conveniently. Thus, the proposed method may arrive at an application level for clinical practice in the future.
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Affiliation(s)
- Shing-Hong Liu
- Department of Computer Science and Information Engineering, Chaoyang University of Technology, Taichung City 41349, Taiwan
| | - Zhi-Kai Yang
- Department of Computer Science and Information Engineering, Chaoyang University of Technology, Taichung City 41349, Taiwan
| | - Kuo-Li Pan
- Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Chiayi Branch, Chiayi City 61363, Taiwan
- College of Medicine, Chang Gung University, Taoyuan City 33305, Taiwan
- Heart Failure Center, Chang Gung Memorial Hospital, Chiayi Branch, Chiayi City 61363, Taiwan
| | - Xin Zhu
- Division of Information Systems, School of Computer Science and Engineering, University of Aizu, Aizu-Wakamatsu City, Fukushima 965-8580, Japan
| | - Wenxi Chen
- Division of Information Systems, School of Computer Science and Engineering, University of Aizu, Aizu-Wakamatsu City, Fukushima 965-8580, Japan
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Cheng KS, Su YL, Kuo LC, Yang TH, Lee CL, Chen W, Liu SH. Muscle Mass Measurement Using Machine Learning Algorithms with Electrical Impedance Myography. SENSORS (BASEL, SWITZERLAND) 2022; 22:3087. [PMID: 35459072 PMCID: PMC9031580 DOI: 10.3390/s22083087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/15/2022] [Accepted: 04/16/2022] [Indexed: 02/04/2023]
Abstract
Sarcopenia is a wild chronic disease among elderly people. Although it does not entail a life-threatening risk, it will increase the adverse risk due to the associated unsteady gait, fall, fractures, and functional disability. The import factors in diagnosing sarcopenia are muscle mass and strength. The examination of muscle mass must be carried in the clinic. However, the loss of muscle mass can be improved by rehabilitation that can be performed in non-medical environments. Electronic impedance myography (EIM) can measure some parameters of muscles that have the correlations with muscle mass and strength. The goal of this study is to use machine learning algorithms to estimate the total mass of thigh muscles (MoTM) with the parameters of EIM and body information. We explored the seven major muscles of lower limbs. The feature selection methods, including recursive feature elimination (RFE) and feature combination, were used to select the optimal features based on the ridge regression (RR) and support vector regression (SVR) models. The optimal features were the resistance of rectus femoris normalized by the thigh circumference, phase of tibialis anterior combined with the gender, and body information, height, and weight. There were 96 subjects involved in this study. The performances of estimating the MoTM used the regression coefficient (r2) and root-mean-square error (RMSE), which were 0.800 and 0.929, and 1.432 kg and 0.980 kg for RR and SVR models, respectively. Thus, the proposed method could have the potential to support people examining their muscle mass in non-medical environments.
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Affiliation(s)
- Kuo-Sheng Cheng
- Department of Biomedical Engineering, National Cheng Kung University, Tainai 701, Taiwan; (K.-S.C.); (Y.-L.S.); (T.-H.Y.)
| | - Ya-Ling Su
- Department of Biomedical Engineering, National Cheng Kung University, Tainai 701, Taiwan; (K.-S.C.); (Y.-L.S.); (T.-H.Y.)
| | - Li-Chieh Kuo
- Department of Occupational Therapy, National Cheng Kung University, Tainan 701, Taiwan;
| | - Tai-Hua Yang
- Department of Biomedical Engineering, National Cheng Kung University, Tainai 701, Taiwan; (K.-S.C.); (Y.-L.S.); (T.-H.Y.)
| | - Chia-Lin Lee
- Department of Physical Education, National Kaohsiung Normal University, Kaohsiung City 80201, Taiwan;
| | - Wenxi Chen
- Biomedical Information Engineering Laboratory, The University of Aizu, Aizu-Wakamatsu City, Fukushima 965-8580, Japan;
| | - Shing-Hong Liu
- Department of Computer Science and Information Engineering, Chaoyang University of Technology, Taichung 413310, Taiwan
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Theoretical and Experimental Study on Assessment of Flow-Mediated Dilatation Using the Cuff Method in Brachial Arteries. ELECTRONICS 2022. [DOI: 10.3390/electronics11030351] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Endothelial dysfunction has been shown to be an important risk factor in the pathogenesis of atherosclerosis, hypertension, and heart failure. The flow-mediated vasodilation (FMD) of the peripheral arteries is an endothelium-dependent function, which is assessed by measuring the diameter change in the brachial artery before and after ischemic stress. Brachial-artery ultrasound scanning (BAUS) is the gold standard for assessing the FMD in clinical practice. However, ultrasonography requires an operator or physician with a professional training to perform accurate measurement of the diameter of the brachial artery. Thus, some studies have used the cuff method to measure the FMD in percentage, the value of which is significantly larger than that using BAUS. The goal of this study was to explore this phenomenon. We explain the interaction between the volume changes (oscillation magnitudes in volume due to cardiac pulsations) of the artery and cuff bladder under different transmural pressures when a sphygmomanometer is wrapped around an upper arm. The compliance of the cuff bladder would be of a fixed value when the cuff pressure is low. The cuff-volume change could be replaced with a cuff-pressure change (oscillation magnitude in cuff pressure due to cardiac pulsation). With the cuff method, the FMDc could be assessed with pressure changes. Then, an inequality formula regarding FMD values by both BAUS (FMDu) and the cuff method (FMDc) was derived; FMDc > 2*FMDu + FMDu2. In order to experimentally verify this inequality formula, fifty-one subjects, including thirty-eight healthy adults and thirteen patients with hypertension, participated in this study. The systolic and diastolic diameters of their brachial arteries and cuff-pressure changes due to cardiac pulsations were separately measured by BAUS and a pressure sensor before and after an ischemic stress. The results showed that FMDu and FMDc were 8.1 ± 4.3% and 121.6 ± 48.6% in the healthy group and 4.5 ± 1.1% and 55.2 ± 22.8% in the patient group, respectively. Thus, the experimental findings comply with the theoretically derived inequality formula.
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Pestel G, Fukui K, Higashi M, Schmidtmann I, Werner C. [Meta-analyses on measurement precision of non-invasive hemodynamic monitoring technologies in adults]. Anaesthesist 2019; 67:409-425. [PMID: 29789877 DOI: 10.1007/s00101-018-0452-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
An ideal non-invasive monitoring system should provide accurate and reproducible measurements of clinically relevant variables that enables clinicians to guide therapy accordingly. The monitor should be rapid, easy to use, readily available at the bedside, operator-independent, cost-effective and should have a minimal risk and side effect profile for patients. An example is the introduction of pulse oximetry, which has become established for non-invasive monitoring of oxygenation worldwide. A corresponding non-invasive monitoring of hemodynamics and perfusion could optimize the anesthesiological treatment to the needs in individual cases. In recent years several non-invasive technologies to monitor hemodynamics in the perioperative setting have been introduced: suprasternal Doppler ultrasound, modified windkessel function, pulse wave transit time, radial artery tonometry, thoracic bioimpedance, endotracheal bioimpedance, bioreactance, and partial CO2 rebreathing have been tested for monitoring cardiac output or stroke volume. The photoelectric finger blood volume clamp technique and respiratory variation of the plethysmography curve have been assessed for monitoring fluid responsiveness. In this manuscript meta-analyses of non-invasive monitoring technologies were performed when non-invasive monitoring technology and reference technology were comparable. The primary evaluation criterion for all studies screened was a Bland-Altman analysis. Experimental and pediatric studies were excluded, as were all studies without a non-invasive monitoring technique or studies without evaluation of cardiac output/stroke volume or fluid responsiveness. Most studies found an acceptable bias with wide limits of agreement. Thus, most non-invasive hemodynamic monitoring technologies cannot be considered to be equivalent to the respective reference method. Studies testing the impact of non-invasive hemodynamic monitoring technologies as a trend evaluation on outcome, as well as studies evaluating alternatives to the finger for capturing the raw signals for hemodynamic assessment, and, finally, studies evaluating technologies based on a flow time measurement are current topics of clinical research.
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Affiliation(s)
- G Pestel
- Klinik für Anästhesiologie, Universitätsmedizin Mainz, Langenbeckstr. 1, 55131, Mainz, Deutschland.
| | - K Fukui
- Klinik für Anästhesiologie, Universitätsmedizin Mainz, Langenbeckstr. 1, 55131, Mainz, Deutschland
| | - M Higashi
- Klinik für Anästhesiologie, Universitätsmedizin Mainz, Langenbeckstr. 1, 55131, Mainz, Deutschland
| | - I Schmidtmann
- Institut für Medizinische Biometrie, Epidemiologie und Informatik (IMBEI), Universitätsmedizin Mainz, Mainz, Deutschland
| | - C Werner
- Klinik für Anästhesiologie, Universitätsmedizin Mainz, Langenbeckstr. 1, 55131, Mainz, Deutschland
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Using the Characteristics of Pulse Waveform to Enhance the Accuracy of Blood Pressure Measurement by a Multi-Dimension Regression Model. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9142922] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
With the advancement of wearable technology, many physiological monitoring instruments are gradually being converted into wearable devices. However, as a consumer product, the blood pressure monitor is still a cuff-type device, which does perform a beat-by-beat continuous blood pressure measurement. Consequently, the cuffless blood pressure measurement device was developed and it is based on the pulse transit time (PTT), although its accuracy remains inadequate. According to the cardiac hemodynamic theorem, blood pressure relates to the arterial characteristics and the contours of the pulse wave include some characteristics of the artery. Therefore, the purpose of this study was to use the contour characteristics of the pulses measured by photoplethysmography (PPG) to estimate the blood pressure using a linear multi-dimension regression model. Ten subjects participated in the experiment, and the blood pressure levels of the subjects were elevated by exercise. The results showed that the mean and standard deviation (mean ± SD) of the root mean square error of the estimated systolic and diastolic pressures within the best five parameters were 6.9 ± 2.81 mmHg and 4.0 ± 0.65 mmHg, respectively. Compared to the results that used one parameter, the PTT, for estimating the systolic and diastolic pressures, 8.2 ± 2.1 mmHg and 4.5 ± 0.79 mmHg, respectively, our results were better.
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Ghosh S, Chattopadhyay BP, Roy RM, Mukherjee J, Mahadevappa M. Estimation of echocardiogram parameters with the aid of impedance cardiography and artificial neural networks. Artif Intell Med 2019; 96:45-58. [PMID: 31164210 DOI: 10.1016/j.artmed.2019.02.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 01/06/2019] [Accepted: 02/13/2019] [Indexed: 11/24/2022]
Abstract
The advent of cardiovascular diseases as a disease of mass catastrophy, in recent years is alarming. It is expected to spread as an epidemic by 2030. Present methods of determining the health of one's heart include doppler based echocardiogram, MDCT (Multi Detector Computed Tomography), among various other invasive and non-invasive hemodynamic monitoring techniques. These methods require expert supervision and costly clinical set-ups, and cannot be employed by a common individual to perform a self diagnosis of one's cardiac health, unassisted. In this work, the authors propose a novel methodology using impedance cardiography (ICG), for the determination of a person's cardio-vascular health. The recorded ICG signal helps in extraction of features which are used for estimating parameters for cardiac health monitoring. The proposed methodology with the aid of artificial neural network is able to determine Stroke Volume (SV), Left Ventricular End Systolic Volume (LVESV), Left Ventricular End Diastolic Volume (LVEDV), Left Ventricular Ejection Fraction (LVEF), Iso Volumetric Contraction Time (IVCT), Iso Volumetric Relaxation Time (IVRT), Left Ventricular Ejection Time (LVET), Total Systolic Time (TST), Total Diastolic Time (TDT), and Myocardial Performance Index (MPI), with error margins of ±8.9%, ±3.8%, ±1.4%, ±7.8%, ±16.0%, ±9.0%, ±9.7%, ±6.9%, ±6.2%, and ±0.9%, respectively. The proposed methodology could be used in screening of precursors to cardiac ailments, and to keep a check on the cardio-vascular health.
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Affiliation(s)
- Sudipta Ghosh
- School of Medical Science & Technology, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India
| | | | - Ram Mohan Roy
- Department of Cardiology, Medical College & Hospital, Kolkata 700073, West Bengal, India
| | - Jayanta Mukherjee
- Department of Computer Science & Engineering, Indian Institute Of Technology Kharagpur, Kharagpur 721302, West Bengal, India
| | - Manjunatha Mahadevappa
- School of Medical Science & Technology, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India.
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Su CH, Liu SH, Tan TH, Lo CH. Using the Pulse Contour Method to Measure the Changes in Stroke Volume during a Passive Leg Raising Test. SENSORS 2018; 18:s18103420. [PMID: 30322018 PMCID: PMC6210240 DOI: 10.3390/s18103420] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 10/04/2018] [Accepted: 10/11/2018] [Indexed: 11/16/2022]
Abstract
The pulse contour method is often used with the Windkessel model to measure stroke volume. We used a digital pressure and flow sensors to detect the parameters of the Windkessel model from the pulse waveform. The objective of this study was to assess the stability and accuracy of this method by making use of the passive leg raising test. We studied 24 healthy subjects (40 ± 9.3 years), and used the Medis® CS 1000, an impedance cardiography, as the comparing reference. The pulse contour method measured the waveform of the brachial artery by using a cuff. The compliance and resistance of the peripheral artery was detected from the cuff characteristics and the blood pressure waveform. Then, according to the method proposed by Romano et al., the stroke volume could be measured. This method was implemented in our designed blood pressure monitor. A passive leg raising test, which could immediately change the preloading of the heart, was done to certify the performance of our method. The pulse contour method and impedance cardiography simultaneously measured the stroke volume. The measurement of the changes in stroke volume using the pulse contour method had a very high correlation with the Medis® CS 1000 measurement, the correlation coefficient of the changed ratio and changed differences in stroke volume were r² = 0.712 and r² = 0.709, respectively. It was shown that the stroke volume measured by using the pulse contour method was not accurate enough. But, the changes in the stroke volume could be accurately measured with this pulse contour method. Changes in stroke volume are often used to understand the conditions of cardiac preloading in the clinical field. Moreover, the operation of the pulse contour method is easier than using impedance cardiography and echocardiography. Thus, this method is suitable to use in different healthcare fields.
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Affiliation(s)
- Chun-Hung Su
- Institute of Medicine, School of Medicine, Chung-Shan Medical University; Department of Internal Medicine, Chung-Shan Medical University Hospital, Taichung 402, Taiwan.
| | - Shing-Hong Liu
- Department of Computer Science and Information Engineering, Chaoyang University of Technology, Taichung 413, Taiwan.
| | - Tan-Hsu Tan
- Department of Electrical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan.
| | - Chien-Hsien Lo
- Department of Internal Medicine, Chung-Shan Medical University Hospital, Taichung 402, Taiwan.
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Functional Activation-Informed Structural Changes during Stroke Recovery: A Longitudinal MRI Study. BIOMED RESEARCH INTERNATIONAL 2017; 2017:4345205. [PMID: 29204440 PMCID: PMC5674725 DOI: 10.1155/2017/4345205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Revised: 06/09/2017] [Accepted: 09/12/2017] [Indexed: 01/21/2023]
Abstract
Objective Neuroimaging studies revealed the functional reorganization or the structural changes during stroke recovery. However, previous studies did not combine the functional and structural information and the results might be affected by heterogeneous lesion. This study aimed to investigate functional activation-informed structural changes during stroke recovery. Methods MRI data of twelve stroke patients were collected at four consecutive time points during the first 3 months after stroke onset. Functional activation during finger-tapping task was used to inform the analysis of structural changes of activated brain regions. Correlation between structural changes in motor-related activated brain regions and motor function recovery was estimated. Results The averaged gray matter volume (aGMV) of contralesional activated brain regions and laterality index of gray matter volume (LIGMV) increased during stroke recovery, and LIGMV was positively correlated with Fugl-Meyer Index (FMI) at initial stage after stroke. The aGMV of bilateral activated brain regions was negatively correlated with FMI during the stroke recovery. Conclusion This study demonstrated that combining the stroke-induced functional reorganization and structural change provided new insights into the underlying innate plasticity process during stroke recovery. Significance This study proposed a new approach to integrate functional and structural information for investigating the innate plasticity after stroke.
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Reshetnik A, Compton F, Schölzel A, Tölle M, Zidek W, Giet MVD. Noninvasive oscillometric cardiac output determination in the intensive care unit - comparison with invasive transpulmonary thermodilution. Sci Rep 2017; 7:9997. [PMID: 28855727 PMCID: PMC5577225 DOI: 10.1038/s41598-017-10527-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 08/09/2017] [Indexed: 11/09/2022] Open
Abstract
Assessment of the cardiac output (CO) is usually performed with invasive techniques requiring specialized equipment in the intensive care unit (ICU). With TEL-O-GRAPH (TG), CO can be derived from the oscillometrically obtained brachial pulse wave during the measurement of brachial blood pressure. CO and stroke volume (SV) determinations with TG were compared with transpulmonary thermodilution measurements with the PICCO system (PICCO) in 38 haemodynamically unstable ICU patients with a total of 84 comparison measurements performed. SV (33.3 ± 9.0 ml/m2 vs. 44.3 ± 14.4 ml/m2, p < 0.001) and CO (2.7 ± 0.5 l/min/m2 vs. 3.8 ± 1.2 l/min/m2, p < 0.001) were underestimated significantly with TG and oscillometric brachial systolic blood pressure (BP) was significantly lower and diastolic BP significantly higher than invasive femoral artery pressure. A linear correlation was found between CO dimension and CO underestimation with TG. Correct tracking of CO changes with a fluid challenge was possible in 69.5% of measurements. Oscillometric noninvasive CO is possible in the ICU, but accuracy and precision of this new method are lacking. Implementation of a correction factor accounting for the linear increase in CO underestimation observed with increasing CO could improve CO assessment with TG in haemodynamically unstable patients.
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Affiliation(s)
- Alexander Reshetnik
- Department of Nephrology and intensive care medicine, Charité Universitaetsmedizin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203, Berlin, Germany.
| | - Friederike Compton
- Department of Nephrology and intensive care medicine, Charité Universitaetsmedizin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Anna Schölzel
- Department of Nephrology and intensive care medicine, Charité Universitaetsmedizin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Markus Tölle
- Department of Nephrology and intensive care medicine, Charité Universitaetsmedizin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Walter Zidek
- Department of Nephrology and intensive care medicine, Charité Universitaetsmedizin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Markus van der Giet
- Department of Nephrology and intensive care medicine, Charité Universitaetsmedizin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203, Berlin, Germany
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Liu SH, Wang JJ, Cheng DC, Su CH, Lin TH. Assessment of the endothelial function with changed volume of brachial artery by menstrual cycle. Biomed Eng Online 2016; 15:106. [PMID: 27599988 PMCID: PMC5012016 DOI: 10.1186/s12938-016-0230-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 08/30/2016] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND The endothelial function has been proven to be an important factor in the pathogenesis of atherosclerosis, hypertension and heart failure. The flow-mediated vasodilation (FMD) of the peripheral artery is an endothelium-dependent function. Brachial-artery ultrasound scanning is the popular method for evaluating FMD. However, good technical training on ultrasonography is required for the user to obtain high-quality data. Therefore, the goal of this study was to propose a new method which only used a sphygmomanometer cuff to occlude the blood flow and record the vascular volume waveform (Vwave). RESULTS We used this method to assess the FMD in the menstrual cycle for 26 volunteer females. All female subjects were evaluated two times (M: menstrual phase; F: luteal phase) in one menstrual cycle and for two cycles. In the first cycle, the FMD volume ratio in M was 101.9 ± 45.5 % and was higher in L, at 137.5 ± 62.1 % (p = 0.0032 versus M). In the second cycle, the FMD volume ratios in M and L were 91.4 ± 37.0 % and 124.0 ± 56.4 %, respectively (p < 0.001 vs. M). CONCLUSIONS Our results have confirmed those results in the study of Hametner et al. Blood pressure measurement and FMD assessment all used the same mechanic of digital blood pressure monitor, which makes our method suitable using at home.
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Affiliation(s)
- Shing-Hong Liu
- Department of Computer Science and Information Engineering, Chaoyang University of Technology, Taichung, Taiwan
| | - Jia-Jung Wang
- Department of Biomedical Engineering, I-Shou University, Kaohsiung, Taiwan
| | - Da-Chuan Cheng
- Department of Biomedical Imaging and Radiological Science, China Medical University, 91, Xueshi Road, Hsueh-Shih Road, Taichung, 40402, Taiwan.
| | - Chun-Hung Su
- Institute of Medicine, School of Medicine, Chung-Shan Medical University, Taichung, Taiwan. .,Department of Internal Medicine, Chung-Shan Medical University Hospital, No.110, Sec.1, Jianguo N. Rd., Taichung, 40201, Taiwan.
| | - Tzu-Hsin Lin
- Department of Cardiology, Lin-Shin Hospital, Taichung, Taiwan
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Shi J, Wang F, Liu S. Radiolabeled cyclic RGD peptides as radiotracers for tumor imaging. BIOPHYSICS REPORTS 2016; 2:1-20. [PMID: 27819026 PMCID: PMC5071373 DOI: 10.1007/s41048-016-0021-8] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 03/01/2016] [Indexed: 12/19/2022] Open
Abstract
The integrin family comprises 24 transmembrane receptors, each a heterodimeric combination of one of 18α and one of 8β subunits. Their main function is to integrate the cell adhesion and interaction with the extracellular microenvironment with the intracellular signaling and cytoskeletal rearrangement through transmitting signals across the cell membrane upon ligand binding. Integrin αvβ3 is a receptor for the extracellular matrix proteins containing arginine–glycine–aspartic (RGD) tripeptide sequence. The αvβ3 is generally expressed in low levels on the epithelial cells and mature endothelial cells, but it is highly expressed in many solid tumors. The αvβ3 levels correlate well with the potential for tumor metastasis and aggressiveness, which make it an important biological target for development of antiangiogenic drugs, and molecular imaging probes for early tumor diagnosis. Over the last decade, many radiolabeled cyclic RGD peptides have been evaluated as radiotracers for imaging tumors by SPECT or PET. Even though they are called “αvβ3-targeted” radiotracers, the radiolabeled cyclic RGD peptides are also able to bind αvβ5, α5β1, α6β4, α4β1, and αvβ6 integrins, which may help enhance their tumor uptake due to the “increased receptor population.” This article will use the multimeric cyclic RGD peptides as examples to illustrate basic principles for development of integrin-targeted radiotracers and focus on different approaches to maximize their tumor uptake and T/B ratios. It will also discuss important assays for pre-clinical evaluations of the integrin-targeted radiotracers, and their potential applications as molecular imaging tools for noninvasive monitoring of tumor metastasis and early detection of the tumor response to antiangiogenic therapy.
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Affiliation(s)
- Jiyun Shi
- Interdisciplinary Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China ; Medical Isotopes Research Center, Peking University, Beijing, 100191 China
| | - Fan Wang
- Interdisciplinary Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China ; Medical Isotopes Research Center, Peking University, Beijing, 100191 China
| | - Shuang Liu
- School of Health Sciences, Purdue University, West Lafayette, IN 47907 USA
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