Related Research Articles
Bradycardia, also called bradyarrhythmia, is a resting heart rate under 60 beats per minute (BPM). While bradycardia can result from a variety of pathologic processes, it is commonly a physiologic response to cardiovascular conditioning, or due to asymptomatic type 1 atrioventricular block. Resting heart rates less than 50 BPM are often normal during sleep in young and healthy adults, and in athletes. In large population studies of adults without underlying heart disease, resting heart rates of 45-50 BPM appear to be the lower limits of normal, dependent on age and sex. Bradycardia is most likely to be discovered in the elderly, as both age and underlying cardiac disease progression contribute to its development.
The diagnostic tests in cardiology are methods of identifying heart conditions associated with healthy vs. unhealthy, pathologic heart function.
Clinical neurophysiology is a medical specialty that studies the central and peripheral nervous systems through the recording of bioelectrical activity, whether spontaneous or stimulated. It encompasses both research regarding the pathophysiology along with clinical methods used to diagnose diseases involving both central and peripheral nervous systems. Examinations in the clinical neurophysiology field are not limited to tests conducted in a laboratory. It is thought of as an extension of a neurologic consultation. Tests that are conducted are concerned with measuring the electrical functions of the brain, spinal cord, and nerves in the limbs and muscles. It can give the precise definition of site, the type and degree of the lesion, along with revealing the abnormalities that are in question. Due to these abilities, clinical neurophysiology is used to mainly help diagnose diseases rather than treat them.
Electrocardiography is the process of producing an electrocardiogram, a recording of the heart's electrical activity through repeated cardiac cycles. It is an electrogram of the heart which is a graph of voltage versus time of the electrical activity of the heart using electrodes placed on the skin. These electrodes detect the small electrical changes that are a consequence of cardiac muscle depolarization followed by repolarization during each cardiac cycle (heartbeat). Changes in the normal ECG pattern occur in numerous cardiac abnormalities, including:
An evoked potential or evoked response is an electrical potential in a specific pattern recorded from a specific part of the nervous system, especially the brain, of a human or other animals following presentation of a stimulus such as a light flash or a pure tone. Different types of potentials result from stimuli of different modalities and types. Evoked potential is distinct from spontaneous potentials as detected by electroencephalography (EEG), electromyography (EMG), or other electrophysiologic recording method. Such potentials are useful for electrodiagnosis and monitoring that include detections of disease and drug-related sensory dysfunction and intraoperative monitoring of sensory pathway integrity.
Biofeedback is the technique of gaining greater awareness of many physiological functions of one's own body by using electronic or other instruments, and with a goal of being able to manipulate the body's systems at will. Humans conduct biofeedback naturally all the time, at varied levels of consciousness and intentionality. Biofeedback and the biofeedback loop can also be thought of as self-regulation. Some of the processes that can be controlled include brainwaves, muscle tone, skin conductance, heart rate and pain perception.
In medicine, a Holter monitor is a type of ambulatory electrocardiography device, a portable device for cardiac monitoring for at least 24 hours.
The cardiac conduction system transmits the signals generated by the sinoatrial node – the heart's pacemaker, to cause the heart muscle to contract, and pump blood through the body's circulatory system. The pacemaking signal travels through the right atrium to the atrioventricular node, along the bundle of His, and through the bundle branches to Purkinje fibers in the walls of the ventricles. The Purkinje fibers transmit the signals more rapidly to stimulate contraction of the ventricles.
Electromyography (EMG) is a technique for evaluating and recording the electrical activity produced by skeletal muscles. EMG is performed using an instrument called an electromyograph to produce a record called an electromyogram. An electromyograph detects the electric potential generated by muscle cells when these cells are electrically or neurologically activated. The signals can be analyzed to detect abnormalities, activation level, or recruitment order, or to analyze the biomechanics of human or animal movement. Needle EMG is an electrodiagnostic medicine technique commonly used by neurologists. Surface EMG is a non-medical procedure used to assess muscle activation by several professionals, including physiotherapists, kinesiologists and biomedical engineers. In computer science, EMG is also used as middleware in gesture recognition towards allowing the input of physical action to a computer as a form of human-computer interaction.
Polysomnography (PSG), a type of sleep study, is a multi-parameter study of sleep and a diagnostic tool in sleep medicine. The test result is called a polysomnogram, also abbreviated PSG. The name is derived from Greek and Latin roots: the Greek πολύς, the Latin somnus ("sleep"), and the Greek γράφειν.
A flatline is an electrical time sequence measurement that shows no activity and therefore, when represented, shows a flat line instead of a moving one. It almost always refers to either a flatlined electrocardiogram, where the heart shows no electrical activity (asystole), or to a flat electroencephalogram, in which the brain shows no electrical activity. Both of these specific cases are involved in various definitions of death.
A biosignal is any signal in living beings that can be continually measured and monitored. The term biosignal is often used to refer to bioelectrical signals, but it may refer to both electrical and non-electrical signals. The usual understanding is to refer only to time-varying signals, although spatial parameter variations are sometimes subsumed as well.
The 10–20 system or International 10–20 system is an internationally recognized method to describe and apply the location of scalp electrodes in the context of an EEG exam, polysomnograph sleep study, or voluntary lab research. This method was developed to maintain standardized testing methods ensuring that a subject's study outcomes could be compiled, reproduced, and effectively analyzed and compared using the scientific method. The system is based on the relationship between the location of an electrode and the underlying area of the brain, specifically the cerebral cortex.
A Bioamplifier is an electrophysiological device, a variation of the instrumentation amplifier, used to gather and increase the signal integrity of physiologic electrical activity for output to various sources. It may be an independent unit, or integrated into the electrodes.
Electroencephalography (EEG) is a method to record an electrogram of the spontaneous electrical activity of the brain. The biosignals detected by EEG have been shown to represent the postsynaptic potentials of pyramidal neurons in the neocortex and allocortex. It is typically non-invasive, with the EEG electrodes placed along the scalp using the International 10–20 system, or variations of it. Electrocorticography, involving surgical placement of electrodes, is sometimes called "intracranial EEG". Clinical interpretation of EEG recordings is most often performed by visual inspection of the tracing or quantitative EEG analysis.
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.
Clinical Electrophysiological Testing is based on techniques derived from electrophysiology used for the clinical diagnosis of patients. There are many processes that occur in the body which produce electrical signals that can be detected. Depending on the location and the source of these signals, distinct methods and techniques have been developed to properly target them.
Electrodiagnosis (EDX) is a method of medical diagnosis that obtains information about diseases by passively recording the electrical activity of body parts or by measuring their response to external electrical stimuli. The most widely used methods of recording spontaneous electrical activity are various forms of electrodiagnostic testing (electrography) such as electrocardiography (ECG), electroencephalography (EEG), and electromyography (EMG). Electrodiagnostic medicine is a medical subspecialty of neurology, clinical neurophysiology, cardiology, and physical medicine and rehabilitation. Electrodiagnostic physicians apply electrophysiologic techniques, including needle electromyography and nerve conduction studies to diagnose, evaluate, and treat people with impairments of the neurologic, neuromuscular, and/or muscular systems. The provision of a quality electrodiagnostic medical evaluation requires extensive scientific knowledge that includes anatomy and physiology of the peripheral nerves and muscles, the physics and biology of the electrical signals generated by muscle and nerve, the instrumentation used to process these signals, and techniques for clinical evaluation of diseases of the peripheral nerves and sensory pathways.
Electrography may refer to electrophotography, that is, Kirlian photography.
Fetal electroencephalography, also known as prenatal EEG includes any recording of electrical fluctuations arising from the brain of a fetus. Doctors and scientists use EEGs to detect and characterize brain activity, such as sleep states, potential seizures, or levels of a coma. EEG captures the electrical activity in the vicinity of the recording electrodes. The majority of the neural electrical activity arises from the flow of current from the cell bodies of pyramidal neurons to their apical dendrites, which become depolarized by excitatory inputs from other neurons. To record the most accurate signals, scientists try to minimize the distance between the recording electrode and the neural activity that they want to detect. Given the difficulty of attaching electrodes to a fetus inside a uterus, doctors and scientists use a variety of techniques to record fetal brain activity.
References
- ↑ "Definition of 'Electrogram'". Collins English Dictionary .
- ↑ Dubey, A.; Ray, S. (2019-05-29). "Cortical Electrocorticogram (ECoG) Is a Local Signal". Journal of Neuroscience. 39 (22): 4299–4311. doi: 10.1523/JNEUROSCI.2917-18.2019 . ISSN 0270-6474. PMC 6538865 . PMID 30914446.