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Sample records for ballistocardiography

  1. Ballistocardiography in sitting and horizontal positions

    International Nuclear Information System (INIS)

    The purpose of this study is to examine the effect of posture in the sitting and supine positions on ballistocardiography (BCG) measurements by using EMFi (electromechanical film) sensors. The experiment, measuring the subject's electrocardiography (ECG), BCG and carotid pulse (CP) signal, was repeated in the sitting and different horizontal positions. Additionally, the duration and the amplitudes of the BCG and CP signal components were studied. Certain properties of BCG differed significantly in the sitting and horizontal positions. Amplitudes of measured signals were larger, and time intervals were greater in the sitting position compared to the supine position. Thus, posture significantly influences cardiac performance evaluated by BCG. Sitting and supine positions are clearly distinguishable in the BCG signal. This provides new methods for evaluation of the hemodynamic changes induced by the body position

  2. Nocturnal Sleep Quality and Quantity Analysis with Ballistocardiography

    OpenAIRE

    Nurmi, Sami

    2016-01-01

    The aim of this thesis was to evaluate usability and performance of a ballistocardiography (BCG) based method for qualitative and quantitative analysis of sleep. The method was validated and the basis for sleep stage detection was presented. Sleep problems are one of the most common medical complaints today. Polysomnography (PSG) as the current standard for sleep analysis is expensive, intrusive and complicated. Thus, finding a reliable and unobtrusive method for longer-term home use is...

  3. MRI-based aortic blood flow model in 3D ballistocardiography.

    Science.gov (United States)

    Lejeune, L; Prisk, G K; Nonclercq, A; Migeotte, P-F

    2015-08-01

    Ballistocardiography (BCG) is a non-invasive technique which measures the acceleration of a body induced by cardiovascular activity, namely the force exerted by the beating heart. A one dimensional aortic flow model based on the transmission lines theory is developped and applied to the simulation of three dimensional BCG. A four-element Windkessel model is used to generate the pressure-wave. Using transverse MRI slices of a human subject, a reconstruction of the aorta allows the extraction of parameters used to relate the local change in mass of the 1D flow model to 3D acceleration BCG. Simulated BCG curves are then compared qualitatively with the ensemble average curves of the same subject recorded in sustained microgravity. Confirming previous studies, the main features of the y-axis are well simulated. The simulated z-axis, never attempted before, shows important similarities. The simulated x-axis is less faithful and suggests the presence of reflections. PMID:26737946

  4. Three-dimensional ballistocardiography in microgravity: a review of past research.

    Science.gov (United States)

    De Ridder, S; Migeotte, P-F; Neyt, X; Pattyn, N; Prisk, G K

    2011-01-01

    This paper gives a short review of research on ballistocardiography in microgravity and indicates the benefits from this research for the use of BCG as a terrestrial cardiac monitoring system. In the past, 3-D methods required large devices to decouple the subject from the terrestrial environment and hence, BCG on Earth is usually limited to unidirectional recordings of the motion in the head-to-foot direction. However, microgravity provides a suspension-free environment where accelerations can be measured in all directions without the influence of gravity. Microgravity research indicated that along with the acceleration in the head-to-foot direction, the accelerations in the lateral and dorso-ventral direction are important in understanding the physiological forces during a cardiac cycle. Further, lung volume has a large influence on the transmission of cardiac forces to the surface of the body. To date, only the three separate components of the acceleration vector have been analyzed in 3-D BCG studies. Using the true acceleration and displacement vector (orientation and magnitude), rather than the three separate components, may permit more accurate cardiac event detection. PMID:22255282

  5. Applying Novel Time-Frequency Moments Singular Value Decomposition Method and Artificial Neural Networks for Ballistocardiography

    Science.gov (United States)

    Akhbardeh, Alireza; Junnila, Sakari; Koivuluoma, Mikko; Koivistoinen, Teemu; Värri, Alpo

    2006-12-01

    As we know, singular value decomposition (SVD) is designed for computing singular values (SVs) of a matrix. Then, if it is used for finding SVs of an [InlineEquation not available: see fulltext.]-by-1 or 1-by- [InlineEquation not available: see fulltext.] array with elements representing samples of a signal, it will return only one singular value that is not enough to express the whole signal. To overcome this problem, we designed a new kind of the feature extraction method which we call ''time-frequency moments singular value decomposition (TFM-SVD).'' In this new method, we use statistical features of time series as well as frequency series (Fourier transform of the signal). This information is then extracted into a certain matrix with a fixed structure and the SVs of that matrix are sought. This transform can be used as a preprocessing stage in pattern clustering methods. The results in using it indicate that the performance of a combined system including this transform and classifiers is comparable with the performance of using other feature extraction methods such as wavelet transforms. To evaluate TFM-SVD, we applied this new method and artificial neural networks (ANNs) for ballistocardiogram (BCG) data clustering to look for probable heart disease of six test subjects. BCG from the test subjects was recorded using a chair-like ballistocardiograph, developed in our project. This kind of device combined with automated recording and analysis would be suitable for use in many places, such as home, office, and so forth. The results show that the method has high performance and it is almost insensitive to BCG waveform latency or nonlinear disturbance.

  6. Applying Novel Time-Frequency Moments Singular Value Decomposition Method and Artificial Neural Networks for Ballistocardiography

    Directory of Open Access Journals (Sweden)

    Koivistoinen Teemu

    2007-01-01

    Full Text Available As we know, singular value decomposition (SVD is designed for computing singular values (SVs of a matrix. Then, if it is used for finding SVs of an -by-1 or 1-by- array with elements representing samples of a signal, it will return only one singular value that is not enough to express the whole signal. To overcome this problem, we designed a new kind of the feature extraction method which we call ''time-frequency moments singular value decomposition (TFM-SVD.'' In this new method, we use statistical features of time series as well as frequency series (Fourier transform of the signal. This information is then extracted into a certain matrix with a fixed structure and the SVs of that matrix are sought. This transform can be used as a preprocessing stage in pattern clustering methods. The results in using it indicate that the performance of a combined system including this transform and classifiers is comparable with the performance of using other feature extraction methods such as wavelet transforms. To evaluate TFM-SVD, we applied this new method and artificial neural networks (ANNs for ballistocardiogram (BCG data clustering to look for probable heart disease of six test subjects. BCG from the test subjects was recorded using a chair-like ballistocardiograph, developed in our project. This kind of device combined with automated recording and analysis would be suitable for use in many places, such as home, office, and so forth. The results show that the method has high performance and it is almost insensitive to BCG waveform latency or nonlinear disturbance.

  7. Applying Novel Time-Frequency Moments Singular Value Decomposition Method and Artificial Neural Networks for Ballistocardiography

    Directory of Open Access Journals (Sweden)

    Alpo Värri

    2007-01-01

    Full Text Available As we know, singular value decomposition (SVD is designed for computing singular values (SVs of a matrix. Then, if it is used for finding SVs of an m-by-1 or 1-by-m array with elements representing samples of a signal, it will return only one singular value that is not enough to express the whole signal. To overcome this problem, we designed a new kind of the feature extraction method which we call ‘‘time-frequency moments singular value decomposition (TFM-SVD.’’ In this new method, we use statistical features of time series as well as frequency series (Fourier transform of the signal. This information is then extracted into a certain matrix with a fixed structure and the SVs of that matrix are sought. This transform can be used as a preprocessing stage in pattern clustering methods. The results in using it indicate that the performance of a combined system including this transform and classifiers is comparable with the performance of using other feature extraction methods such as wavelet transforms. To evaluate TFM-SVD, we applied this new method and artificial neural networks (ANNs for ballistocardiogram (BCG data clustering to look for probable heart disease of six test subjects. BCG from the test subjects was recorded using a chair-like ballistocardiograph, developed in our project. This kind of device combined with automated recording and analysis would be suitable for use in many places, such as home, office, and so forth. The results show that the method has high performance and it is almost insensitive to BCG waveform latency or nonlinear disturbance.

  8. Identifying sleep apnea syndrome using heart rate and breathing effort variation analysis based on ballistocardiography.

    Science.gov (United States)

    Weichao Zhao; Hongbo Ni; Xingshe Zhou; Yalong Song; Tianben Wang

    2015-08-01

    Sleep apnea syndrome (SAS) is regarded as one of the most common sleep-related breathing disorders, which can severely affect sleep quality. Since SAS is usually accompanied with the cyclical heart rate variation (HRV), many studies have been conducted on heart rate (HR) to identify it at an earlier stage. While most related work mainly based on clinical devices or signals (e.g., polysomnography (PSG), electrocardiography (ECG)), in this paper we focus on the ballistocardiographic (BCG) signal which is obtained in a non-invasive way. Moreover, as the precision and reliability of BCG signal are not so good as PSG or ECG, we propose a fine-grained feature extraction and analysis approach in SAS recognition. Our analysis takes both the basic HRV features and the breathing effort variation into consideration during different sleep stages rather than the whole night. The breathing effort refers to the mechanical interaction between respiration and BCG signal when SAS events occur, which is independent from autonomous nervous system (ANS) modulations. Specifically, a novel method named STC-Min is presented to extract the breathing effort variation feature. The basic HRV features depict the ANS modulations on HR and Sample Entropy and Detrended Fluctuation Analysis are applied for the evaluations. All the extracted features along with personal factors are fed into the knowledge-based support vector machine (KSVM) classification model, and the prior knowledge is based on dataset distribution and domain knowledge. Experimental results on 42 subjects in 3 nights validate the effectiveness of the methods and features in identifying SAS (90.46% precision rate and 88.89% recall rate). PMID:26737303

  9. A NOVEL BCG SENSOR-ARRAY FOR UNOBTRUSIVE CARDIAC MONITORING

    OpenAIRE

    Anna Böhm; Christoph Brüser; Steffen Leonhardt Leonhardt

    2013-01-01

    Unobtrusive heart rate monitoring is a popular research topic in biomedical engineering. The reason is that convential methods, e.g. the clinical gold standard electrocardiography, require conductive contact to the human body. Other methods such as ballistocardiography try to record these vital signs without electrodes that are attached to the body. So far, these systems cannot replace routine procedures. Most systems have some drawbacks that cannot be compensated, such as aging of the sensor...

  10. PoC: Pilvipalveluun tallennettavan terveystiedon parsiminen Pythonilla

    OpenAIRE

    Ahola, Antti

    2016-01-01

    Opinnäytetyön aiheena oli Pilvipalveluun tallennettavan terveystiedon parsiminen Pythonilla. Työssä tutustutaan mHealthiin, pilvipalveluihin sekä proof of conceptin toteuttamiseen vaadittavaan teknologiaan. Työn tavoitteena oli suorittaa proof of concept, jossa BCG-anturista (Ballistocardiography) saatu terveysdata parsitaan Python-ohjelmointikielellä ja siirretään MySQL-tietokantaan. BCG-anturi on erittäin herkkä kiihtyvyysanturi, joka mittaa sydämen sykkimisestä aiheutuvia kiihtyvyyksiä...

  11. [Stress-protective properties of lithium nicotinate--a new derivative of nicotinic acid].

    Science.gov (United States)

    Kresiun, V I

    1984-03-01

    Experiments were made to study stress-protective properties of a new psychotropic agent lithium nicotinate developed on the basis of natural metabolites. Prophylactic treatment of the drug given in courses entails an increase in the physical endurance and work fitness, improvement of animals' orientation under stress, facilitating the avoidance behavior. These effects were particularly demonstrable in highly emotional animals. In these animals, stress produced a paralyzing action. According to the electro- and ballisto-cardiography, the drug prevented the stress-induced disorders of cardiovascular function. PMID:6538449

  12. Less Contact Ballistogram Recording during Sleep as a Perspective Technology for the Medical Monitoring System in a Mission to Mars

    Science.gov (United States)

    Baevsky, R. M.; Bogomolov, V. V.; Funtova, I. I.

    strong argument for success of a future Martian mission is absence of pathologies developed in cosmonauts following one-year or longer space flights that might forbid further gradual extension of piloted missions. However, functional shifts in the neurohormonal regulation revealed during the long-term Mir missions suggest that homeostasis of the vital important body systems is maintained owing to active functioning of the regulatory mechanisms (Grigoriev A.I. et al., 1998). Since overstrain of these mechanisms constitutes one of the main factors of risk of diseases, it is important to provide unfailing and systematic monitoring of the body regulation functional reserves. night ballistocardiography, made it possible to obtain data on super-slow heart rhythm fluctuations reflective of activation of the neurohormonal regulation (Baevsky R.M. et al., 1999). Analysis of the data showed that on a background of extended exposure of the human organism to various stressful factors the cardiovascular homeostasis is maintained through consecutive recruitment in adaptation of higher levels of regulation of the physiological systems (Grigoriev A.I., Baevsky R.M., 2001). This validates the hypothesis concerning the role of the higher autonomous centers in long-term adaptation to the spaceflight factors and opens up the new way to diagnosis and prediction of the human body functional reserves. It was first demonstrated in space during the Mir primary mission 9 in 1991. Sensor-accelerometer secured to cosmonaut's sleeping bag registered micromovements conditioned by the heart, respiratory and motor activities of a sleeping cosmonaut. The joint Russian-Austrian space investigations in 1992-1995 resulted in technology refinement and enhancement. Advantages of medical monitoring during sleep are obvious not only because of the time saving and opportunity to receive systematically information pertaining to the crew health. Records allow, to begin with, evaluate the functional state in

  13. Unobtrusive Non-Contact Detection of Arrhythmias using a “Smart” Bed

    Directory of Open Access Journals (Sweden)

    Ch. Brueser

    2011-01-01

    Full Text Available We present an instrumented bed for unobtrusive, non-contact monitoring of cardiac and respiratory activity. The system presented here is based on the principle of ballistocardiography (BCG, and measures cardiopulmonary vibrations of the body by means of an electromechanical foil (EMFi attached to the mattress. Using our system, a clinical study with 13 participants was conducted to assess the BCG’s ability to distinguish atrial fibrillations from normal sinus rhythms. By computing a time-frequency representation of the recorded signals based on parametric autoregressive estimators, we can show clear qualitative differences between normal and arrhythmic BCG episodes. The same distinctive features could also be observed when applying our method to a simultaneously recorded reference ECG. Our results suggest that ECG and BCG both contain the same basic information with respect to the presence of atrial fibrillations, and that a bed-mounted BCG sensor can indeed be used to detect atrial fibrillations.

  14. A NOVEL BCG SENSOR-ARRAY FOR UNOBTRUSIVE CARDIAC MONITORING

    Directory of Open Access Journals (Sweden)

    Anna Böhm

    2013-12-01

    Full Text Available Unobtrusive heart rate monitoring is a popular research topic in biomedical engineering. The reason is that convential methods, e.g. the clinical gold standard electrocardiography, require conductive contact to the human body. Other methods such as ballistocardiography try to record these vital signs without electrodes that are attached to the body. So far, these systems cannot replace routine procedures. Most systems have some drawbacks that cannot be compensated, such as aging of the sensor materials or movement artifacts. In addition, the signal form differs greatly from an ECG, which is an electrical signal. The ballistocardiogram has a mechanical source, which makes it harder to evaluate. We have developed a new sensor array made of near-IR-LEDs to record BCGs. IR-sensors do not age in relevant time scales. Analog filtering was neccesary, because the signal amplitude was very small. The digitized data was then processed by various algorithms to extract beat-to-beat or breath-to-breath intervals. The redundancy of multiple BCG channels was used to provide a robust estimation of beat-to-beat intervals and heart rate. We installed the system beneath a mattress topper of a hospital bed, but any other bed would have been sufficient. The validation of this measurement system shows that it is well suited for BCG recordings. The use of multiple channels has proven to be superior to relying on a single BCG channel.

  15. A low-noise ac-bridge amplifier for ballistocardiogram measurement on an electronic weighing scale

    International Nuclear Information System (INIS)

    Ballistocardiography is a non-invasive technique for evaluating cardiovascular health. This note presents an ac-bridge amplifier for low-noise ballistocardiogram (BCG) recording from a modified weighing scale. The strain gauges in a commercial scale were excited by an ac source—square or sine wave—and the differential output voltage resulting from the BCG was amplified and demodulated synchronously with the excitation waveform. A standard BCG amplifier, with a simple dc-bridge excitation, was also built and the performance was compared to both the square- and sine-wave excited ac-bridge amplifiers. The total input-referred voltage noise (rms) integrated over the relevant BCG bandwidth of 0.3–10 Hz was found to be 30 nV (square wave source) or 25 nV (sine-wave source) for the ac-bridge amplifier and 52 nV for the standard amplifier: an improvement of 4.8 dB or 6 dB, respectively. These correspond to input-referred force noise (rms) values of 5 mN, 4 mN and 8.3 mN. The improvement in SNR was also observed in recorded waveforms from a seated subject whose BCG signal was measured with both dc- and ac-bridge circuits. (note)

  16. The application of a piezo-resistive cardiorespiratory sensor system in an automobile safety belt.

    Science.gov (United States)

    Hamdani, Syed Talha Ali; Fernando, Anura

    2015-01-01

    Respiratory and heart failure are conditions that can occur with little warning and may also be difficult to predict. Therefore continuous monitoring of these bio-signals is advantageous for ensuring human health. The car safety belt is mainly designed to secure the occupants of the vehicle in the event of an accident. In the current research a prototype safety belt is developed, which is used to acquire respiratory and heart signals, under laboratory conditions. The current safety belt is constructed using a copper ink based nonwoven material, which works based on the piezo-resistive effect due to the pressure exerted on the sensor as a result of expansion of the thorax/abdomen area of the body for respiration and due to the principle of ballistocardiography (BCG) in heart signal sensing. In this research, the development of a theoretical model to qualitatively describe the piezo-resistive material is also presented in order to predict the relative change in the resistance of the piezo-resistive material due to the pressure applied. PMID:25831088

  17. The Application of a Piezo-Resistive Cardiorespiratory Sensor System in an Automobile Safety Belt

    Directory of Open Access Journals (Sweden)

    Syed Talha Ali Hamdani

    2015-03-01

    Full Text Available Respiratory and heart failure are conditions that can occur with little warning and may also be difficult to predict. Therefore continuous monitoring of these bio-signals is advantageous for ensuring human health. The car safety belt is mainly designed to secure the occupants of the vehicle in the event of an accident. In the current research a prototype safety belt is developed, which is used to acquire respiratory and heart signals, under laboratory conditions. The current safety belt is constructed using a copper ink based nonwoven material, which works based on the piezo-resistive effect due to the pressure exerted on the sensor as a result of expansion of the thorax/abdomen area of the body for respiration and due to the principle of ballistocardiography (BCG in heart signal sensing. In this research, the development of a theoretical model to qualitatively describe the piezo-resistive material is also presented in order to predict the relative change in the resistance of the piezo-resistive material due to the pressure applied.