Phonocardiogram

Last updated
Phonocardiogram
Phonocardiogram.jpg
Phonocardiogram and jugular venous pulse tracing from a middle-aged man with pulmonary hypertension (pulmonary artery pressure 70 mm Hg) caused by cardiomyopathy. The jugular venous pulse tracing demonstrates a prominent a wave without a c or v wave being observed. The phonocardiograms (fourth left interspace and cardiac apex) show a murmur of tricuspid insufficiency and ventricular and atrial gallops. [1]
Synonyms PCG
ICD-9-CM 89.55
Phonocardiograms of common murmurs. Phonocardiograms from normal and abnormal heart sounds.png
Phonocardiograms of common murmurs.

A phonocardiogram (or PCG) is a plot of high-fidelity recording of the sounds and murmurs made by the heart with the help of the machine called the phonocardiograph; thus, phonocardiography is the recording of all the sounds made by the heart during a cardiac cycle. [2] [3]

Contents

Medical use

Wiggers diagram of various events of a cardiac cycle, including a phonocardiogram at bottom. Wiggers Diagram.svg
Wiggers diagram of various events of a cardiac cycle, including a phonocardiogram at bottom.

Heart sounds result from vibrations created by the closure of the heart valves. There are at least two; the first (S1) is produced when the atrioventricular valves (tricuspid and mitral) close at the beginning of systole and the second (S2) when the aortic valve and pulmonary valve (semilunar valves) close at the end of systole. [4] Phonocardiography allows the detection of subaudible sounds and murmurs and makes a permanent record of these events. [5] In contrast, the stethoscope cannot always detect all such sounds or murmurs and provides no record of their occurrence. The ability to quantitate the sounds made by the heart provides information not readily available from more sophisticated tests and provides vital information about the effects of certain drugs on the heart. It is also an effective method for tracking the progress of a patient's disease.[ medical citation needed ]

Discrete and the packet wavelet transform

According to a review by Cherif et al., discrete wavelet transform DWT is better at not affecting S1 or S2 while filtering heart murmurs. Packet wavelet transform affects internal components structure much more than DWT does. [6]

History

William Birnbaum with a Phonocardiogram System for use in Project Gemini, 1965 William Birnbaum with a Phonocardiogram System 4t64gn45n.tiff
William Birnbaum with a Phonocardiogram System for use in Project Gemini, 1965

Awareness of the sounds made by the heart dates to ancient times. The idea of developing an instrument to record it may date back to Robert Hooke (1635–1703), who wrote: "There may also be a possibility of discovering the internal motions and actions of bodies - whether animal, vegetable, or mineral, by the sound they make". The earliest known examples of phonocardiography date to the 1800s. [7]

Monitoring and recording equipment for phonocardiography was developed through the 1930s and 1940s. Standardization began by 1950, when the first international conference was held in Paris. [7]

A phonocardiogram system manufactured by Beckman Instruments was used on at least one of the Project Gemini manned spaceflights (1965–1966) to monitor the heartbeat of astronauts on the flight. It was one of many Beckman Instruments specialized for and used by NASA. [8]

John Keefer filed a patent for a phonocardiogram simulator in 1970 while he was an employee of the U.S. government. The original patent description indicates that it is a device which via electrical voltage mimics the human heart's sounds. [9]

Fetal Phonocardiogram

A fetal phonocardiogram (or fPCG) is a specialized application of phonocardiography designed to be a non-invasive diagnostic technique to capture the sounds of the fetal heart in utero. These fetalphonocardiograms can be analyzed to detect any abnormalities in the fetal heart. Fetal phonocardiography has become an important tool in prenatal care, as it allows clinicians to detect and monitor potential heart problems in the fetus before birth. [10]

The use of phonocardiography to study the fetal heart dates back to the 1960s, when researchers first began to explore the feasibility of detecting fetal heart sounds using external microphones. [10] Early studies focused on using phonocardiography to measure fetal heart rate and rhythm. Over time, advances in technology and techniques have enabled researchers to use fetal phonocardiography to detect a wider range of fetal heart abnormalities. [11] [12] Fetal phonocardiography is typically performed during routine prenatal visits, starting around 18–20 weeks of gestation. The procedure involves placing a small microphone on the mother's abdomen over the fetal heart. The microphone captures the sounds of the fetal heart, which are then amplified and recorded for analysis. Khandoker et al. developed a multi-channel fetal phonocardiogram (fPCG) with four sound transducers applied in a simple and consistent pattern across the maternal abdomen. [13] [14] The intellectual property (IP) technology license was given to the home-based monitoring device, the Emirati startup, that helps pregnant mothers monitor fetal heartbeat and the baby’s cardiac activity. [15]

See also

Related Research Articles

<span class="mw-page-title-main">Stethoscope</span> Medical device for auscultation

The stethoscope is a medical device for auscultation, or listening to internal sounds of an animal or human body. It typically has a small disc-shaped resonator that is placed against the skin, with either one or two tubes connected to two earpieces. A stethoscope can be used to listen to the sounds made by the heart, lungs or intestines, as well as blood flow in arteries and veins. In combination with a manual sphygmomanometer, it is commonly used when measuring blood pressure.

<span class="mw-page-title-main">Heart murmur</span> Medical condition

Heart murmurs are unique heart sounds produced when blood flows across a heart valve or blood vessel. This occurs when turbulent blood flow creates a sound loud enough to hear with a stethoscope. The sound differs from normal heart sounds by their characteristics. For example, heart murmurs may have a distinct pitch, duration and timing. The major way health care providers examine the heart on physical exam is heart auscultation; another clinical technique is palpation, which can detect by touch when such turbulence causes the vibrations called cardiac thrill. A murmur is a sign found during the cardiac exam. Murmurs are of various types and are important in the detection of cardiac and valvular pathologies.

<span class="mw-page-title-main">Palpitations</span> Perceived cardiac abnormality in which ones heartbeat can be felt

Palpitations are perceived abnormalities of the heartbeat characterized by awareness of cardiac muscle contractions in the chest, which is further characterized by the hard, fast and/or irregular beatings of the heart.

<span class="mw-page-title-main">Mitral valve prolapse</span> Medical condition

Mitral valve prolapse (MVP) is a valvular heart disease characterized by the displacement of an abnormally thickened mitral valve leaflet into the left atrium during systole. It is the primary form of myxomatous degeneration of the valve. There are various types of MVP, broadly classified as classic and nonclassic. In severe cases of classic MVP, complications include mitral regurgitation, infective endocarditis, congestive heart failure, and, in rare circumstances, cardiac arrest.

<span class="mw-page-title-main">Auscultation</span> Listening to the internal sounds of the body, usually using a stethoscope

Auscultation is listening to the internal sounds of the body, usually using a stethoscope. Auscultation is performed for the purposes of examining the circulatory and respiratory systems, as well as the alimentary canal.

<span class="mw-page-title-main">Pulmonary valve</span> Semilunar valve of the heart

The pulmonary valve is a valve of the heart that lies between the right ventricle and the pulmonary artery, and has three cusps. It is one of the four valves of the heart and one of the two semilunar valves, the other being the aortic valve. Similar to the aortic valve, the pulmonary valve opens in ventricular systole when the pressure in the right ventricle rises above the pressure in the pulmonary artery. At the end of ventricular systole, when the pressure in the right ventricle falls rapidly, the pressure in the pulmonary artery closes the pulmonary valve.

<span class="mw-page-title-main">Aortic regurgitation</span> Medical condition

Aortic regurgitation (AR), also known as aortic insufficiency (AI), is the leaking of the aortic valve of the heart that causes blood to flow in the reverse direction during ventricular diastole, from the aorta into the left ventricle. As a consequence, the cardiac muscle is forced to work harder than normal.

<span class="mw-page-title-main">Photoplethysmogram</span> Chart of tissue blood volume changes

A photoplethysmogram (PPG) is an optically obtained plethysmogram that can be used to detect blood volume changes in the microvascular bed of tissue. A PPG is often obtained by using a pulse oximeter which illuminates the skin and measures changes in light absorption. A conventional pulse oximeter monitors the perfusion of blood to the dermis and subcutaneous tissue of the skin.

<span class="mw-page-title-main">Mitral regurgitation</span> Form of valvular heart disease

Mitral regurgitation (MR), also known as mitral insufficiency or mitral incompetence, is a form of valvular heart disease in which the mitral valve is insufficient and does not close properly when the heart pumps out blood. It is the abnormal leaking of blood backwards – regurgitation from the left ventricle, through the mitral valve, into the left atrium, when the left ventricle contracts. Mitral regurgitation is the most common form of valvular heart disease.

Sonicaid Ltd was a medical electronics company headquartered in West Sussex best known for its range of Doppler fetal monitors. The company also developed early ultrasound scanners. The word "Sonicaid" is in generic use for Doppler fetal monitors. Sonicaid is now a registered trademark of Huntleigh Healthcare.

<span class="mw-page-title-main">Wavelet transform</span> Mathematical technique used in data compression and analysis

In mathematics, a wavelet series is a representation of a square-integrable function by a certain orthonormal series generated by a wavelet. This article provides a formal, mathematical definition of an orthonormal wavelet and of the integral wavelet transform.

Geophysical survey is the systematic collection of geophysical data for spatial studies. Detection and analysis of the geophysical signals forms the core of Geophysical signal processing. The magnetic and gravitational fields emanating from the Earth's interior hold essential information concerning seismic activities and the internal structure. Hence, detection and analysis of the electric and Magnetic fields is very crucial. As the Electromagnetic and gravitational waves are multi-dimensional signals, all the 1-D transformation techniques can be extended for the analysis of these signals as well. Hence this article also discusses multi-dimensional signal processing techniques.

<span class="mw-page-title-main">Computer-aided diagnosis</span> Type of diagnosis assisted by computers

Computer-aided detection (CADe), also called computer-aided diagnosis (CADx), are systems that assist doctors in the interpretation of medical images. Imaging techniques in X-ray, MRI, Endoscopy, and ultrasound diagnostics yield a great deal of information that the radiologist or other medical professional has to analyze and evaluate comprehensively in a short time. CAD systems process digital images or videos for typical appearances and to highlight conspicuous sections, such as possible diseases, in order to offer input to support a decision taken by the professional.

<span class="mw-page-title-main">Third heart sound</span> Medical condition

The third heart sound or S3 is a rare extra heart sound that occurs soon after the normal two "lub-dub" heart sounds (S1 and S2). S3 is associated with heart failure.

<span class="mw-page-title-main">Magnetomyography</span>

Magnetomyography (MMG) is a technique for mapping muscle activity by recording magnetic fields produced by electrical currents occurring naturally in the muscles, using arrays of SQUIDs. It has a better capability than electromyography for detecting slow or direct currents. The magnitude of the MMG signal is in the scale of pico (10−12) to femto (10−15) Tesla (T). Miniaturizing MMG offers a prospect to modernize the bulky SQUID to wearable miniaturized magnetic sensors.

Computer-aided auscultation (CAA), or computerized assisted auscultation, is a digital form of auscultation. It includes the recording, visualization, storage, analysis and sharing of digital recordings of heart or lung sounds. The recordings are obtained using an electronic stethoscope or similarly suitable recording device. Computer-aided auscultation is designed to assist health care professionals who perform auscultation as part of their diagnostic process. Commercial CAA products are usually classified as clinical decision support systems that support medical professionals in making a diagnosis. As such they are medical devices and require certification or approval from a competent authority.

<span class="mw-page-title-main">Doppler ultrasonography</span> Ultrasound imaging of the movement of tissues and body fluids using the Doppler effect

Doppler ultrasonography is medical ultrasonography that employs the Doppler effect to perform imaging of the movement of tissues and body fluids, and their relative velocity to the probe. By calculating the frequency shift of a particular sample volume, for example, flow in an artery or a jet of blood flow over a heart valve, its speed and direction can be determined and visualized.

Bio-radiolocation is a technology for remote detection and diagnostics of biological objects by means of radar, even behind optically opaque obstacles. Devices based on this method are called bio-radars.

<span class="mw-page-title-main">Ear-EEG</span>

Ear-EEG is a method for measuring dynamics of brain activity through the minute voltage changes observable on the skin, typically by placing electrodes on the scalp. In ear-EEG, the electrodes are exclusively placed in or around the outer ear, resulting in both a much greater invisibility and wearer mobility compared to full scalp electroencephalography (EEG), but also significantly reduced signal amplitude, as well as reduction in the number of brain regions in which activity can be measured. It may broadly be partitioned into two groups: those using electrode positions exclusively within the concha and ear canal, and those also placing electrodes close to the ear, usually hidden behind the ear lobe. Generally speaking, the first type will be the most invisible, but also offer the most challenging (noisy) signal. Ear-EEG is a good candidate for inclusion in a hearable device, however, due to the high complexity of ear-EEG sensors, this has not yet been done.

<span class="mw-page-title-main">Pulse watch</span> Electronic devices

A pulse watch, also known as a pulsometer or pulsograph, is an individual monitoring and measuring device with the ability to measure heart or pulse rate. Detection can occur in real time or can be saved and stored for later review. The pulse watch measures electrocardiography data while the user is performing tasks, whether it be simple daily tasks or intense physical activity. The pulse watch functions without the use of wires and multiple sensors. This makes it useful in health and medical settings where wires and sensors may be an inconvenience. Use of the device is also common in sport and exercise environments where individuals are required to measure and monitor their biometric data.

References

  1. https://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=cm&part=A622&rendertype=figure&id=A633 Chapter 8/no page given/Google
  2. Tang, Hong; Zhang, Jinhui; Sun, Jian; Qiu, Tianshuang; Park, Yongwan (2016-04-01). "Phonocardiogram signal compression using sound repetition and vector quantization". Computers in Biology and Medicine. 71: 24–34. doi: 10.1016/j.compbiomed.2016.01.017 . ISSN   0010-4825. PMID   26871603.
  3. Silverman, Mark E.; Fleming, Peter R.; Hollman, Arthur; Julian, Desmond G.; Krikler, Dennis M. (2012-12-06). British Cardiology in the 20th Century. Springer Science & Business Media. ISBN   9781447107736.Chapter 8/no Google page given
  4. Hall, John E. (2015-04-23). Pocket Companion to Guyton & Hall Textbook of Medical Physiology. Elsevier Health Sciences. p. 283. ISBN   9780323375238.
  5. Daniels, Rick (2009). Delmar's Manual of Laboratory and Diagnostic Tests . Cengage Learning. p.  800. ISBN   978-1418020668 . Retrieved 27 November 2016. phonocardiogram purpose.
  6. Cherif, L. Hamza; Debbal, S. M.; Bereksi-Reguig, F. (1 March 2010). "Choice of the wavelet analyzing in the phonocardiogram signal analysis using the discrete and the packet wavelet transform". Expert Systems with Applications. 37 (2): 913–918. doi:10.1016/j.eswa.2009.09.036.
  7. 1 2 Sprague, H. B. (December 1957). "History and Present Status of Phonocardiography". IRE Transactions on Medical Electronics. PGME-9: 2–3. doi:10.1109/IRET-ME.1957.5008615. ISSN   0097-1049.
  8. "Beckman Instruments Supplying Medical Flight Monitoring Equipment" (PDF). Space News Roundup. March 3, 1965. pp. 4–5. Retrieved 7 August 2019.
  9. M, Keefer John (Apr 28, 1970), Phonocardiogram simulator , retrieved 2016-06-02
  10. 1 2 Morgenstern, J; Abels, T; Leblanc, R; Naumann, U; Schettler, H; Wolf, P (1986-01-01), Rolfe, Peter (ed.), "Chapter 19 - The fetal phonocardiogram", Fetal Physiological Measurements, Butterworth-Heinemann, pp. 115–123, doi:10.1016/b978-0-407-00450-4.50021-6, ISBN   978-0-407-00450-4 , retrieved 2023-08-30
  11. Koutsiana, Elisavet; Hadjileontiadis, Leontios J.; Chouvarda, Ioanna; Khandoker, Ahsan H. (2017-09-08). "Fetal Heart Sounds Detection Using Wavelet Transform and Fractal Dimension". Frontiers in Bioengineering and Biotechnology. 5: 49. doi: 10.3389/fbioe.2017.00049 . ISSN   2296-4185. PMC   5596097 . PMID   28944222.
  12. Marzbanrad, Faezeh; Kimura, Yoshitaka; Endo, Miyuki; Palaniswami, Marimuthu; Khandoker, Ahsan H. (August 2015). "Transfer entropy analysis of maternal and fetal heart rate coupling". 2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). Vol. 2015. IEEE. pp. 7865–7868. doi:10.1109/embc.2015.7320215. ISBN   978-1-4244-9271-8. PMID   26738115. S2CID   32510704.
  13. Khandoker, Ahsan; Ibrahim, Emad; Oshio, Sayaka; Kimura, Yoshitaka (2018-09-11). "Validation of beat by beat fetal heart signals acquired from four-channel fetal phonocardiogram with fetal electrocardiogram in healthy late pregnancy". Scientific Reports. 8 (1): 13635. Bibcode:2018NatSR...813635K. doi: 10.1038/s41598-018-31898-1 . ISSN   2045-2322. PMC   6134006 . PMID   30206289.
  14. "Novel digital device to detect heart murmurs". gulfnews.com. 2015-03-28. Retrieved 2023-08-30.
  15. National, The (2020-03-18). "Khalifa University grants IP licence to Emirati startup". The National. Retrieved 2023-08-30.

Further reading