Abstract— The electrocardiogram (ECG) is widely used for the detection of cardiac diseases. Normally, the recorded ECG signal is often contaminated by noise. In order to extract the useful information from the noisy ECG signal, the raw ECG signal has to be proceed. The detection of QRS complexes in an ECG signal provides information about the heart rate, the conduction velocity, the condition of tissues within the heart as well as various abnormalities. An algorithm based on wavelet transforms (WT)has been developed for detecting ECG characteristics points. The wavelet based ECG detector consist of a wavelet decomposer with wavelet filter banks, a QRS complex detector of hypothesis testing with wavelet-demodulated ECG signal, and a noise detector
One of the most commonly implemented biomedical devices is the cardiac pacemaker, which is widely used to detect, monitor and guarantee the patient’s heart-beating rate within a safe range. Fig.1 shows a block diagram of the implantable pacemaker integrated circuit (IPIC). The Electrocardiogram (ECG) detector checks the heart-beating rate and rhythm with the digitized ECG signals from an analog-to-digital converter (ADC). When an abnormal heart-beating is detected, electrical stimulations are applied to the heart using the high-voltage multiplier and pulse generator. In order to achieve a high guarantee of safety for the patients, high detection reliability is the most essential property of the cardiac pacemaker. Moreover, once it is implanted inside human body[1], the pacemaker is expected to operate over several years without changing the battery. To avoid repeated surgeries due to battery exhaustion, low power consumption is another extremely important design requirement for IPIC extremely important design requirement for IPIC.
Fig 1.Block diagram of cardiac pacemker[1]
According to previous research works, while the analog circuits including amplifiers and bias circuit take about half of the overall
This detector is based on the wavelet filter bank that decomposes the input signal into sub bands[2]. The threshold function of the hypothesis test determines whether the incoming beat is considered as cardiac activity or as noise. The electrical activity at the pacemaker electrode tip is reflected by the intra-cardiac electrogram (EGM). The depolarization and repolarization waves are decomposed into two perpendicular waves: one that propagates horizontally and another that propagates transversally to the myocardial wall. Thus, the morphologies of these two waves differ significantly. The horizontal wave is composed of a large positive charge that rapidly changes to a negative charge resulting in a biphasic wave, whereas the transversal wave results in a monophasic wave[8]. Ventricular depolarization usually represents the cardiac event in an EGM and is referred to as the “R-wave”. Its duration is normally between 60 and 100 ms
There are several different heart problems that show up as an abnormal EKG reading. For example, a heart block can occur when there is a delay in the signals coming from the SA node, AV node, or the Purkinje fibers. However, clinically the term heart block is used to refer to an AV block. This delays or completely stops communication between the atria and the ventricles. AV block is shown on the EKG as a delayed or prolonged PR interval. The P wave represents the activity in the atria, and the QRS complex represents ventricular activity. This is why the PR interval shows the signal delay from the AV node. There are three degrees of severity, and if the delay is greater than .2 seconds it is classified as first degree. Second degree is classified by several regularly spaced P waves before each QRS complex. Third degree can be shown by P waves that have no spacing relationship to the QRS complex. Another type of blockage is bundle branch block. This is caused by a blockage in the bundle of His, creating a delay in the electrical signals traveling down the bundle branches to reach the ventricles. This results in a slowed heart beat, or brachycardia. On an EKG reading this is shown as a prolonged QRS complex. A normal QRS is about .8-.12 seconds, and anything longer is considered bundle branch block. Another type of abnormal EKG reading is atrial fibrillation, when the atria contracts very quickly. On the EKG this is shown by no clear P waves, only many small fibrillating waves, and no PR interval to measure. This results in a rapid and irregular heartbeat. On the other hand, ventricular fibrillation is much more serious and can cause sudden death if not treated by electrical defibrillation.
In this lab, I took two recordings of my heart using an electrocardiogram. An electrocardiogram, EKG pg. 628 Y and pg. 688 D, is a recording of the heart's electrical impulses, action potentials, going through the heart. The different phases of the EKG are referred to as waves; the P wave, QRS Complex, and the T wave. These waves each signify the different things that are occurring in the heart. For example, the P wave occurs when the sinoatrial (SA) node, aka the pacemaker, fires an action potential. This causes the atria, which is currently full of blood, to depolarize and to contract, aka atrial systole. The signal travels from the SA node to the atrioventricular (AV) node during the P-Q segment of the EKG. The AV node purposefully delays
Two heart sounds are normally heard through a stethoscope on the chest wall, "lab" "dap". The first sound can be described as soft, but resonant, and longer then the second one. This sound is associated with the closure of AV valves (atrioventricular valves) at the beginning of systole. The second sound is louder and sharp. It is associated with closure of the pulmonary and aortic valves (semilunar valves) at the beginning of diastole. There is a pause between the each set of sounds. It is a period of total heat relaxation called quiescent period.
Cardiac monitoring has been available since the early 1960s (Henriques-Forsythe, Ivonye, Jamched, Kamuguisha, Olejeme & Onwuanyi, 2009). George, Walsh-Irwin, Queen, Vander Heuvel, Hawkins, & Roberts (2015) explain, “Remote telemetry monitoring is the monitoring of cardiac rhythms of acute care inpatients from a central locate by personnel who are not directly involved with patient care” (p. 11). Researchers and authors published a multitude of articles, best practices, and standards for hospital monitoring (Drew, 2004, Funk, 2010). A basic internet query reveals injuries and deaths related to remote telemetry monitoring. Guidelines, best practices, and research provide the best evidence in the delivery of safe quality care
In the early 1950s, the first ever amazing invention of an external cardiac Pacemaker was developed by Dr. John Hopps. It was large (about 30 cm long, and several centimetres high and wide), the pulses were generated by vacuum tubes and the entire unit was powered by 60 Hz household current.(The Pacemaker) Hopps was an electric engineer appointed by the National Research Council of Canada in 1941 after training at the University of Manitoba as an electrical engineer. Pacemakers helped with the pumping of blood by sending electric signals but it occupied too much space. John Hopps was recognized as “The Father of Biomedical Engineering”. "The financial cost of the pacemaker was minimal" which made the pacemaker even popular and appealing as a weapon to treat problems in rhythm of the heart. (Drew)
The study of cardio physiology was broken up into five distinct parts all centering on the cardiovascular system. The first lab was utilization of the electrocardiogram (ECG). This studied the electrical activities of the heart by placing electrodes on different parts of the skin. This results in a graph on calibrated paper of these activities. These graphs are useful in the diagnosis of heart disease and heart abnormalities. Alongside natural heart abnormalities are those induced by chemical substances. The electrocardiogram is useful in showing how these chemicals adjust the electrical impulses that it induces.
The two assessment tools chosen are the 12 lead ECG and blood tests. The 12 lead ECG provides more detailed views and angles of the hearts electrical activity in both horizontal and frontal planes. The 12 lead has 6 limb leads and the other 6 for chest leads (Phalen & Aehlert, 2006).
Lidwell and Edgar H. Booth invented the first pacemaker. It was a portable device that consisting of two poles, one of which included a needle that would be plunged into a cardiac chamber. It was very crude, but it succeeded in reviving a stillborn baby at a Sydney hospital in 1928. The decades that followed, inventors came up with increasingly sophisticated versions of the pacemaker. However, these devices; which relied upon vacuum tubes; remained heavy and bulky, affording little or no mobility for patients. Colombian electrical engineer Jorge Reynolds Pombo developed a pacemaker in 1958 weighed 99 lbs and was powered by a 12-volt auto battery. Surgeons at the Karolinska Institute in Sweden were the first to place a fully implantable device into a patient in 1958. Rune Elmqvist and surgeon Ake Senning invented this pacemaker, which was implanted in the chest of Arne Larsson. The first device failed after three hours, the second after two days. Larsson would have 26 different pacemakers implanted in him. He died at the age of 86 in 2001, outliving both Elmqvist and Senning. In the world there are many heart attacks and as people grow they can get abnormalities in there heart(Medlineplus). When someone 's heart stops working it can be fixed with a pacemaker, it makes the heart beat properly. The artificial pacemaker is a wonder of modern science. A small, implantable device that regulates a human heartbeat through electrical impulses have saved millions of lives. The development of this vital medical device owes much to the advances in electronics and communications brought about by the Space Age.Pacemakers may be used for people who have heart problems that cause their heart to beat too slowly. A slow heartbeat is called Bradycardia two common problems that cause a slow heartbeat are sinus node disease and heart block. When your heart
AIM: - the aim of this experiment is to find out what the effects of exercise are on the heart rate. And to record these results in various formats. VARIABLES: - * Type of exercise * Duration of exercise * Intensity of exercise * Stage of respiration
The heart is a pump with four chambers made of their own special muscle called cardiac muscle. Its interwoven muscle fibers enable the heart to contract or squeeze together automatically (Colombo 7). It’s about the same size of a fist and weighs some where around two hundred fifty to three hundred fifty grams (Marieb 432). The size of the heart depends on a person’s height and size. The heart wall is enclosed in three layers: superficial epicardium, middle epicardium, and deep epicardium. It is then enclosed in a double-walled sac called the Pericardium. The terms Systole and Diastole refer respectively and literally to the contraction and relaxation periods of heart activity (Marieb 432). While the doctor is taking a patient’s blood pressure, he listens for the contractions and relaxations of the heart. He also listens for them to make sure that they are going in a single rhythm, to make sure that there are no arrhythmias or complications. The heart muscle does not depend on the nervous system. If the nervous s...
In a normal strip, one can clearly identify a P wave before every QRS complex, which is then followed by a T wave; in Atrial Fibrillation, the Sinoatrial node fires irregularly causing there to be no clear P wave and an irregular QRS complex (Ignatavicius & Workman, 2013). Basically, it means that the atria, the upper chambers of the heart, are contracting too quickly and no clear P wave is identified because of this ‘fibrillation’ (Ignatavicius & Workman, 2013). Clinical Manifestations and Pathophysiology A normal heart rhythm begins at the sinoatrial node and follows the heart's conduction pathway without any problems. Typically the sinoatrial node fires between 60-100 times per minute (Ignatavicius & Workman, 2013).
Pacemakers are an electrical pulse regulatory mechanism, that helps create well balanced heart beats in patients in need. Pacemaker monitoring in the past has been limited to Physician visits, and emergent visit to the hospitals. Proper pacemaker monitoring with real-time implications leaves new insight and advancement within the medical field; while delivering real-time possible life saving patient information to appropriate personnel.
Basic Mathematics for Electronics seventh edition: Nelson M. Cooke, Herbert F.R Adams, Peter B. Dell, T. Adair Moore; Copyright 1960
A microprocessor inside the defibrillator interprets (analyzes) the victim's heart rhythm through adhesive electrodes (some AED models require you to press an ANALYZE button). The computer analyzes the heart rhythm and advises the operator whether a shock is needed. AEDs advise a shock only to ventricular fibrillation and fast ventricular tachycardia. The electric current is delivered through the victim's chest wall through adhesive electrode pads.
Hickey, H. (2011, July 11). Wireless power could cut cord for patients with implanted heart pumps. Retrieved from http://www.washington.edu/news/2011/07/12/wireless-power-could-cut-cord-for-patients-with-implanted-heart-pumps/