Pulse Wave Characteristics Research Articles

Pulse Wave Cycle Features Analysis of Different Blood Pressure Grades in the Elderly.

Background and Objective The same range of blood pressure values may reflect different vascular functions, especially in the elderly. Therefore, a single blood pressure value may not comprehensively reveal cardiovascular function. This study focused on identifying pulse wave features in the elderly that can be used to show functional differences when blood pressure values are in the same range. Methods First, pulse data were preprocessed and pulse cycles were segmented. Second, time domain, higher-order statistics, and energy features of wavelet packet decomposition coefficients were extracted. Finally, useful pulse wave features were evaluated using a feature selection and classifier design. Results A total of 6,075 pulse wave cycles were grouped into 3 types according to different blood pressure levels and each group was divided into 2 categories according to a history of hypertension. The classification accuracy of feature selection in the 3 groups was 97.91%, 95.24%, and 92.28%, respectively. Conclusion Selected features could be appropriately used to analyze cardiovascular function in the elderly and can serve as the basis for research on a cardiovascular risk assessment model based on Traditional Chinese Medicine pulse diagnosis.

Mathematical modeling of pulse wave propagation along human aorta

Background: Physical characteristics of pulse waves, which are generated by the heart contractions and propagated along the arteries, are used in medicine for diagnostics of the blood circulation system and blood supply to the organs and tissues. At the sites with significant wave reflections the high local pressure oscillations appear that may lead to damage of the endothelium, development of atherosclerotic plaques and aortic aneurysm. Therefore, elaboration of a detailed biophysical model of the individual aorta based on tomography and determination of the dangerous sites with high wave reflections are important for medical diagnostics. Objectives: The aim of the work is to study the regularities of the pulse wave propagation and reflection along the aorta and to propose new methods for early diagnosis of disorders in the blood circulation system. Materials and methods: The measurement data on diameters and lengths of segments of aorta and its branches conducted on 5 corpses have been used. Calculations of the wave conduction and reflection coefficients are based on the linear theory of pulse waves developed by J. Lighthill. Results: It is shown that from the biophysical point of view, the aorta is an optimal waveguide, which provides almost zero local reflections of the pulse waves. Most of the branches possess negative reflection, which accelerates the blood flow and decreases the load on the heart due to the suction effect. The calculated values of the branching coefficients and pulse waves speeds correspond to the data of the previous experimental measurements. It is shown that most of the branches have an optimal Murray coefficient close to one. It implies, aorta also provides the optimal volumetric blood flow over the period of cardiac contraction with minimal energy expenses. Conclusions: Human aorta and its branches possess optimal biophysical properties, which ensure the blood flow with minimal energy consumption. Aorta as an optimal waveguide provides pulse wave propagation with almost without reflection. The proposed method of estimation of the biophysical properties of aorta as a waveguide can be useful for medical diagnostics, allowing early identification of the regions which are dangerous in terms of the progressive development of vascular pathologies in the individual geometry of the patient's vasculature.

A novel flexible pressure sensor array for depth information of radial artery

Pulse wave collection from multi-points of radial artery under different static pressures is an essential method to diagnose diseases. However, there are some problems in the currently-used measuring instruments. Single-type sensor has limitations to pulse wave acquisition. It is not enough to set three sampling points to detect variation trend of radial artery pulse wave. Adaptation to different wrist surfaces and mutual interference of sensors are neglected. This paper proposes a novel flexible compound pressure sensor array for measuring radial artery pulse wave to overcome the problems mentioned above. Our compound pressure sensor consists of a piezoelectric sensor and a piezoresistive sensor which are used to measure pulse wave and static pressure separately. A bending structure of the sensor could guarantee the signal intensity and prevent the occurrence of inverted waveform. In this study, poroelastic materials are used to achieve flexible connection and decrease interference among sensors. In addition, the amplitude characteristics of pulse wave in radial artery are described and the arrangement and size of the sensor array is designed based on statistical data. Anti-interference, repeatability and validation experiments are carried out to evaluate the performance of the sensor array. The results show that the flexible compound pressure sensor array not only reflects depth information of radial artery pulse wave under a wide range of static pressures, but also has good repeatability and anti-interference performance.

Aortic hemodynamics in postmenopausal women following cessation of hormone therapy.

Central (aortic) blood pressure and aortic pulse wave characteristics are measures of cardiovascular health, predictive of cardiovascular mortality. Previous studies have compared aortic hemodynamics in women who do and do not take menopausal hormone therapy, but characteristics of these parameters following cessation of treatment have not been defined. Therefore, the purpose of this study was to define aortic pulse wave characteristics in postmenopausal women with and without a history of menopausal hormone therapy use. Pulse wave analysis was conducted on 67 women who had participated in the randomized, double‐blind, placebo‐controlled Kronos Early Estrogen Prevention Study (KEEPS), 3 years subsequent to the four‐year treatment period. Treatment was oral conjugated equine estrogen (0.45 mg/day; n = 18); transdermal 17β‐estradiol (50 μg/day; n = 23) each with oral micronized progesterone (Prometrium 200 mg); and placebo pills and patch (n = 26). At post‐treatment, median age (60 years) and body mass index (27 kg/m2) did not differ across prior treatment assignment. Aortic blood pressures (median systolic 115 mm Hg and diastolic 76 mm Hg) and augmentation index (median 33%) did not differ among women across prior treatment assignment. These results suggest that these doses and formulations of menopausal hormone therapy had no long‐term effects on central vascular function 3 years after cessation of treatment.

Detection of multipoint pulse waves and dynamic 3D pulse shape of the radial artery based on binocular vision theory

Background and objectivePulse signals contain a wealth of human physiological and pathological information. How to get full pulse information is especially challenging, and most of the traditional pulse sensors can only get the pulse wave of a single point. This study is aimed at developing a binocular pulse detection system and method to obtain multipoint pulse waves and dynamic three-dimensional pulse shape of the radial artery. MethodsThe proposed pulse detection approach is image-based and implemented by two steps. First, a new binocular pulse detection system is developed based on the principle of pulse feeling used in traditional Chinese medicine. Second, pulse detection is achieved based on theories and methods of binocular vision and digital image processing. In detail, the sequences of pulse images collected by the designed system as experimental data are sequentially processed by median filtering, block binarization and inversion, area filtering, centroids extraction of connected regions, to extract the pattern centroids as feature points. Then stereo matching is realized by a proposed algorithm based on Gong-shape scan detection. After multipoint spatial coordinate calculation, dynamic three-dimensional reconstruction of the thin film shape is completed by linear interpolation. And then the three-dimensional pulse shape is achieved by finding an appropriate reference time. Meanwhile, extraction of multipoint pulse waves of the radial artery is accomplished by using a suitable reference origin. The proposed method is analyzed from three aspects, which are pulse amplitude, pulse rate and pulse shape, and compared with other detection methods. ResultsAnalysis of the results shows that the values of pulse amplitude and pulse rate are consistent with the characteristics of pulse wave of the radial artery, and pulse shape can correctly present the shape of pulse in space and its change trend in time. The comparison results with the other two previously proposed methods further verify the correctness of the presented method. ConclusionsThe designed binocular pulse detection system and proposed algorithm can effectively detect pulse information. This tactile visualization-based pulse detection method has important scientific significance and broad application prospects and will promote further development of objective pulse diagnosis.

Evaluation of Propagation Characteristics of Pulse Waves in Dispersive Nonlinear Photonic Crystal Waveguides

Evaluation of Propagation Characteristics of Pulse Waves in Dispersive Nonlinear Photonic Crystal Waveguides

A pulse wave monitoring system based on a respiratory pacemaker

We constructed a reasonable healthcare monitoring system with pulse wave and respiratory analysis to assess blood vessel conditions and the autonomic function in daily life. Filter circuits with an infrared sensor were carefully designed to complete the peripheral pulse wave measurement and analysis, considering individual differences to a pulse sensor and the potential for the system to be used as wearable devices and applications. The analyzer for our system is capable of predicting arterial states and stiffness. A user interface with a respiratory pacemaker can assist voluntary breathing, visualize pulse wave features, and regulate them in real time. The user interface software is widely compatible and could be easily applied to mobile healthcare devices. We also evaluated how respiration control reflected pulse rate variability [i.e., fluctuations in peak-to-peak intervals (PPI)] associated with the autonomic nervous system. An experimental study under various breathing rates was performed using the created user interface with a respiratory pacemaker. The transfer gain of the PPI caused resonance at the respiratory rate of 0.1 Hz (p < 0.5), corresponding to the sufficiently stimulated vagal tone of the heart. A simulation study revealed that the fuzzy inference indicates the robustness of respiratory regulation to maximize the amplitude of PPI oscillations under the inclusion of individual difference and unexpected response. As future perspective, the respiratory pacemaker used to regulate the pulse wave feature could be applied to an effective recovery support system especially under blunted autonomic function such as during mental stress and hypoxia.

Development of a Cardiovascular Simulator for Studying Pulse Diagnosis Mechanisms.

This research was undertaken to develop a cardiovascular simulator for use in the study of pulse diagnosis. The physical (i.e., pulse wave transmission and reflection) and physiological (i.e., systolic and diastolic pressure, pulse pressure, and mean pressure) characteristics of the radial pulse wave were reproduced by our simulator. The simulator consisted of an arterial component and a pulse-generating component. Computer simulation was used to simplify the arterial component while maintaining the elastic modulus and artery size. To improve the reflected wave characteristics, a palmar arch was incorporated within the simulator. The simulated radial pulse showed good agreement with clinical data.

Influence of sympathetic nerve activity on aortic hemodynamics and pulse wave velocity in women.

Central (aortic) blood pressure, arterial stiffness, and sympathetic nerve activity increase with age in women. However, it is unknown if the age-related increase in sympathetic activity influences aortic hemodynamics and carotid-femoral pulse wave velocity (cfPWV), an index of central aortic stiffness. The goal of this study was to determine if aortic hemodynamics and cfPWV are directly influenced by sympathetic nerve activity by measuring aortic hemodynamics, cfPWV, and muscle sympathetic nerve activity (MSNA) in women before and during autonomic ganglionic blockade with trimethaphan camsylate. We studied 12 young premenopausal (23 ± 4 yr) and 12 older postmenopausal (57 ± 3 yr) women. These women did not differ in body mass index or mean arterial pressure (P > 0.05 for both). At baseline, postmenopausal women had higher aortic pulse pressure, augmented pressure, augmentation index adjusted for a heart rate of 75 beats/min, wasted left ventricular pressure energy, and cfPWV than young women (P < 0.05). During ganglionic blockade, postmenopausal women had a greater decrease in these variables in comparison to young women (P < 0.05). Additionally, baseline MSNA was negatively correlated with the reductions in aortic pulse pressure, augmented pressure, and wasted left ventricular pressure energy during ganglionic blockade in postmenopausal women (P < 0.05) but not young women. Baseline MSNA was not correlated with the changes in augmentation index adjusted for a heart rate of 75 beats/min or cfPWV in either group (P > 0.05 for all). Our results suggest that some aortic hemodynamic parameters are influenced by sympathetic activity to a greater extent in older postmenopausal women than in young premenopausal women.NEW & NOTEWORTHY Autonomic ganglionic blockade results in significant decreases in multiple aortic pulse wave characteristics (e.g., augmented pressure) and central pulse wave velocity in older postmenopausal women but not in young premenopausal women. Certain aortic pulse wave parameters are negatively influenced by sympathetic activity to a greater extent in older postmenopausal women.

Recognition of Pulse Wave Feature Points and Non-invasive Blood Pressure Measurement

Humans have a variety of pulse waveforms based on their physiological state. The recognition of the feature points of the pulse wave is very helpful in analyzing the body's physiological and pathological conditions and in preventing and diagnosing cardiovascular diseases. This paper proposes an accurate recognition algorithm of the feature points based on wavelet analysis and time domain characteristics of the pulse wave. Further, this study examines the Hidden Markov Model and performs non-invasive blood pressure estimation on a number of subjects. The experiments show that the algorithm can effectively identify the feature points of the pulse wave. The results of the model are consistent with the actual measurement results and the correlation coefficient reached 96 %, which indicates that the algorithm is significant as a method for non-invasive blood pressure monitoring.

Parameters of Overnight Pulse Wave under Treatment in Obstructive Sleep Apnea

Background: Sleep-related breathing disorders may promote cardiovascular (CV) diseases. A novel and differentiated approach to overnight photoplethysmographic pulse wave analysis, which includes risk assessment and measurement of various pulse wave characteristics, has been evaluated in obstructive sleep apnea (OSA). Objectives: The purpose of this study was to assess if and which of the differentiated pulse wave characteristics might be influenced by OSA treatment with positive airway pressure (PAP). Methods: The study included two protocols. In the case-control study (group A), pulse wave-derived CV risk indices recorded during PAP therapy were compared with those obtained in age, body mass index, and CV risk class-matched patients with untreated OSA (n = 67/67). In the prospective PAP treatment study (group B), 17 unselected patients undergoing a full-night sleep test at baseline and after 23 ± 19 weeks of treatment were analyzed. Results: In untreated OSA patients (group A), the overnight hypoxic load was increased (SpO₂ index 38.7 ± 17.5 vs. 24.0 ± 11.1, p < 0.001) and the pulse wave attenuation index (PWA-I) was lower (29.4 ± 9.2 vs. 33.5 ± 11.8, p = 0.022) than in treated patients. In group B, PAP therapy reduced the hypoxic load and increased the PWA-I significantly. The composite CV risk index was slightly but not significantly reduced. Conclusions: PAP therapy modified the hypoxic load and pulse wave-derived markers. The PWA-I - associated with sympathetic vascular tone - was most prominently modified by PAP. This novel approach to markers of CV function should be further evaluated in prospective studies.

Real-time arrhythmia detection with supplementary ECG quality and pulse wave monitoring for the reduction of false alarms in ICUs

False intensive care unit (ICU) alarms induce stress in both patients and clinical staff and decrease the quality of care, thus significantly increasing both the hospital recovery time and rehospitalization rates. In the PhysioNet/CinC Challenge 2015 for reducing false arrhythmia alarms in ICU bedside monitor data, this paper validates the application of a real-time arrhythmia detection library (ADLib, Schiller AG) for the robust detection of five types of life-threatening arrhythmia alarms. The strength of the application is to give immediate feedback on the arrhythmia event within a scan interval of 3 s–7.5 s, and to increase the noise immunity of electrocardiogram (ECG) arrhythmia analysis by fusing its decision with supplementary ECG quality interpretation and real-time pulse wave monitoring (quality and hemodynamics) using arterial blood pressure or photoplethysmographic signals. We achieved the third-ranked real-time score (79.41) in the challenge (Event 1), however, the rank was not officially recognized due to the ‘closed-source’ entry. This study shows the optimization of the alarm decision module, using tunable parameters such as the scan interval, lead quality threshold, and pulse wave features, with a follow-up improvement of the real-time score (80.07). The performance (true positive rate, true negative rate) is reported in the blinded challenge test set for different arrhythmias: asystole (83%, 96%), extreme bradycardia (100%, 90%), extreme tachycardia (98%, 80%), ventricular tachycardia (84%, 82%), and ventricular fibrillation (78%, 84%). Another part of this study considers the validation of ADLib with four reference ECG databases (AHA, EDB, SVDB, MIT-BIH) according to the international recommendations for performance reports in ECG monitors (ANSI/AAMI EC57). The sensitivity (Se) and positive predictivity (+P) are: QRS detector QRS (Se, +P) > 99.7%, ventricular ectopic beat (VEB) classifier VEB (Se, +P) = 95%, and ventricular fibrillation detector VFIB (P + = 94.8%) > VFIB (Se = 86.4%), adjusted to the clinical setting requirements, giving preference to low false positive alarms.

Pulse Wave Detection Magnetoelastic Sensing Device Based on Nanocrystalline Microwires for the Indirect Diagnosis of Paroxysmal Rhythm Disorders

The results on a new magnetoelastic sensing device for monitoring the pulse wave characteristics are reported. The main application area for this device is the indirect diagnosis of paroxysmal rhythm disorders. The proposed device is employing a novel nanocrystalline microwire with enhanced soft magnetic properties, obtained after accurate post-processing treatments. It has a high sensitivity to detect the pulse wave, being at the same time small and autonomous (battery operated). It also has a large internal memory for data storage and Internet connectivity options. The information processed and stored by the device is extremely useful for healthcare professionals and for patients with cardiac arrhythmias. The monitoring of the main parameters of the pulse wave, such as frequency, regularity, and signal amplitude, allows one to differentiate a regular arrhythmia from an irregular one. Online transmission of the recorded pulse wave information is helpful for telediagnosis and for home monitoring of patients with paroxysmal rhythm disorders.

Methods for reliable estimation of pulse transit time and blood pressure variations using smartphone sensors

Hypertension is known to affect around one third of adults globally and early diagnosis is essential to reduce the effects of this affliction. Today’s Blood Pressure (BP) monitoring cuffs are obtrusive and inconvenient for performing regular measurements, and continuous non-invasive blood pressure devices are too complex and expensive for ambulatory use. Hence, there is a strong need for affordable systems that can measure blood pressure (BP) variations throughout the day as this will allow to monitor, diagnose and follow-up not only patients at risk, but also healthy population in general for early diagnosis. A promising method for arterial BP estimation is to measure the Pulse Transit Time (PTT) and derive pressure values from it. However, current methods for measuring this surrogate marker of BP require complex sensing and analysis circuitry and the related medical devices are expensive and inconvenient for the user. In this paper, we present new methods to estimate PTT reliably and subsequently BP, from the baseline sensors of smartphones. This new approach involves determining PTT by simultaneously measuring the time the blood leaves the heart, by recording the heart sound using the standard microphone of the phone, and the time it reaches the finger, by measuring the pulse wave using the phone’s camera. We present algorithms that can be executed directly on current smartphones to obtain clean and robust heart sound signals and to extract the pulse wave characteristics. We also present methods to ensure a synchronous capture of the waveforms, which is essential to obtain reliable PTT values with inexpensive sensors. Additionally, we combine Autocorrelation and Fast Fourier Transform (FFT)-based methods for reliably estimating the user heart rate (HR) from his/her heart sounds, and describe how to use the calculate HR to compensate for the camera frame rate variations and to improve the robustness of PTT estimation. Our experiments show that the computational overhead of the proposed processing methods is minimum, which allows real-time feedback to the user, and that the PTT values are fully accurate (beat-to-beat), thereby enabling state-of-the-art smartphones to be used as affordable medical devices.

The Fixed Combination of Amlodipine and Bisoprolol Eliminates the Effect of -Blockers on Central Pulse Wave in Patients With Arterial Hypertension

to assess effect of -blockers in the characteristics of the central pulse wave and the effect of switching to a fixed bisoprolol/amlodipine (B/A) combination. Untreated patients (n=28, age 53.6+/-5.7 years, 19 men) with uncomplicated hypertension without diabetes were given bisoprolol 5-10 mg. After 4 weeks at blood pressure (BP) >40/90 mmHg amlodipine (5 mg) was added by switching to a fixed B/A combination. The dose of amlodipine in this combination was increased to 10 mg in order to achieve target BP. The duration of combination therapy was 8 weeks. Analysis of the contour of central pulse wave and measurement of pulse wave velocity between carotid and femoral arteries (PWV) were evaluated before treatment, after monotherapy with bisoprolol, and after therapy with fixed B/A combination. After monotherapy with bisoprolol 5 patients achieved BP control, 23 were switched to a fixed B/A combination. Monotherapy with bisoprolol reduced mainly peripheral BP and increased augmentation index (AI) of aortic pulse pressure, normalized to heart rate of 75 beats/min (AI-75). Switching to a fixed B/A combination resulted in further reduction of peripheral BP and significantly greater lowering of central systolic and pulse pressure, return of AI-75 to baseline values, significant decrease of PWVCA. Switching to a fixed B/A combination eliminates the potentially undesirable effects of -blockers on the parameters of the reflected wave, thus resulting in effective lowering of central systolic and pulse BP, and reduction of PWV.

Abstract P138: Novel Arterial Stiffness Index Was Associated with Pulmonary Function

Introduction: Recent studies have shown that the results of vascular function tests, such as pulse wave velocity or cardio-ankle vascular index (CAVI), were associated with pulmonary function in children or hypertensive patients, and increased CAVI might be correlated with progression of chronic obstructive pulmonary disease. However, the association between vascular function and pulmonary function remains unclear, especially in healthy adult people. Arterial velocity index (AVI) is a novel arterial stiffness index that can be measured more easily than previous methods. The aim of this study was to investigate the association between AVI and pulmonary function test results in the healthy adult population. Methods: We conducted a cross-sectional survey of healthy adults aged 20 years or older at a single large medical center in Hachinohe, Japan between April 2014 and March 2015. We measured AVI using cuff oscillometry. AVI means the characteristics of pulse waves at higher cuff pressure than systolic BP. The outcome measure was forced expiratory volume in one second (FEV1), which was measured with spirometry. We used log-transformed values of AVI and FEV1, as the distributions of these values were skewed. We calculated a correlation coefficient between AVI and FEV1, and performed multiple linear regression analyses to adjust for effects of age, sex, height, and smoking status. Results: In total, 777 men and 530 women participated in this study. The mean age of total participants was 44.9 years (SD = 5.9), and the percentage of current smokers was 32.0 % (418 out of 1,307). The mean AVI was 15.6 (SD = 4.9), and the mean FEV1 was 3.13 L (SD = 0.65). AVI was negatively correlated with FEV1 (r = –0.21, p &lt; 0.001). In fully-adjusted models, AVI was independently associated with FEV1 (β = –0.03, p = 0.017, 95 % CI = –0.06 to –0.01). Conclusions: Our study showed that an increase of arterial stiffness as assessed via AVI was independently associated with a decrease in FEV1 in the healthy Japanese population. Further study is warranted to confirm these findings in cohort studies.

Inverse-model-based cuffless blood pressure estimation using a single photoplethysmography sensor.

This paper proposes an inverse-model-based cuffless method for estimating blood pressure using a single photoplethysmography sensor. The proposed method, which is based on the relationship between blood pressure and the features of pulse waves, employs an inverse estimation and uses the blood pressure as the explanatory variable. Using this method, the blood pressure can be estimated with high accuracy even in situations where the pulse wave features are scattered, as the method uses the dynamic signal-to-noise ratio of the Taguchi method. In order to verify the effectiveness of the proposed method, we employed it to measure the systolic blood pressure. It could be confirmed that the estimation accuracy of the proposed method is higher than that of similar methods.

Aortic Pulse Wave Characteristics In Postmenopausal Women With And Without A History Of Hypertensive Pregnancy

&lt;a name=“OLE_LINK2”&gt;&lt;/a&gt;&lt;a name=“OLE_LINK1”&gt;Hypertensive pregnancy (HP) disorders have been linked to a four‐fold increased risk for development of future cardiovascular diseases. We examined whether history of HP in postmenopausal women (N=20, 59±5 yr) influenced the risk factors for cardiovascular disease as assessed by aortic pulse wave characteristics, compared to age and parity matched controls (N=18, 60±4 yr). Non‐invasive aortic pressure waveforms were synthesized from high‐fidelity pressure waveforms obtained from SphygmoCor applanation tonometry using the radial artery. Aortic systolic and diastolic blood pressure (ASBP, ADBP), aortic augmentation index (AIx), augmented pressure (AP), aortic pulse pressure (APP), and left ventricular wasted energy (Ew) were calculated from the generated aortic pressure waveform. There were no differences in ASBP (125±4 vs. 129±4 mmHg), ADBP (79±2 vs. 81±2 mmHg), AP (17±2 vs. 17±2 mmHg), AIx (35±2 vs. 29±1%), AIx @75BPM (31±2 vs. 29±1%), Ew (3313±338 vs. 3364±432 dynes/cm2/s), between women with a history of HP vs. matched controls, respectively (P&gt;0.05 for all). Body mass index was significantly higher in women with a history of HP (30.6±1 vs. 26.7±1 kg/m2, P&lt;0.05), however it did not statistically influence any of the indices (P&gt;0.05 for all). Our results suggest that postmenopausal women with a history of HP do not demonstrate elevated aortic blood pressure or altered aortic pulse wave characteristics in comparison to matched controls. &lt;/a&gt;Supported by: National Institute of Aging 1P50AG044170‐01 and CTSA UL1 TR000135 and HL 118154

Mask-Less Electrochemical Additive Manufacturing: A Feasibility Study

Additive manufacturing (AM) of metallic structures by laser based layered manufacturing processes involve thermal damages. In this work, the feasibility of mask-less electrochemical deposition as a nonthermal metallic AM process has been studied. Layer by layer localized electrochemical deposition using a microtool tip has been performed to manufacture nickel microstructures. Three-dimensional free hanging structures with about 600 μm height and 600 μm overhang are manufactured to establish the process capability. An inhouse built CNC system was integrated in this study with an electrochemical cell to achieve 30 layers thick microparts in about 5 h by AM directly from STL files generated from corresponding CAD models. The layer thickness achieved in this process was about 10 μm and the minimum feature size depends on the tool width. Simulation studies of electrochemical deposition performed to understand the pulse wave characteristics and their effects on the localization of the deposits.

Method of Photoplethysmography Diagnostics of Domesticated Animals Cardiovascular Diseases

At present time the standard procedure to diagnose cardiovascular diseases (CVD) of domesticated animals (dogs) is electrocardiography (ECG) monitoring at animal clinic. Sadly, results, obtained that way, are often mistaken because of stressful state of the animal, caused by medical manipulations [1]. The usage of photoplethysmography (PPG) method can become a good substitute for CVD monitoring. Main advantages of PPG, in compare with ECG, are single probe placement (on the ear or tailset), no need of gel electrodes and capability of measuring actual CVS parameters without need of special medical training or laboratory conditions. It is one of non-invasive methods for measuring the amount of the blood volume changes inside the blood vessels, applicable for cardio activity estimation by calculating heart rate variability. In most cases, PPG monitoring devises are small, easy to place and can monitor different physiological parameters of the animal, such as heart rate, pulse wave characteristics, blood oxygen saturation, etc.