Biomedical
signals
are
observations
of
physiological activities of organisms, ranging
Biomedical Signal Processing
from gene and protein sequences, to neural and cardiac rhythms, to tissue and organ images. Biomedical signal processing aims at extracting significant information from biomedical signals. With the aid of biomedical signal processing, physiologists can discover new physiology and physicians can monitor distinct illnesses.
课程安排
第一讲 第二讲 第三讲 第四讲 第五讲 第六讲 第七讲 第八讲 第九讲 第十讲 第十一讲 考试 绪论 时域分析 频谱分析 现代信号处理技术 脑机接口 应用举例 图像处理基础 图像增强 图像重建 图像压缩与编码 图像分割 Chapter1 Introduction
装卸过桥1. Biomedical signal 2. Characteristics of biomedical signal 3. Application 4. Common signal processing algorithm 5. Commonly used software of signal processing
1. Biomedical signal
physiologic signals 主动信号(active signal )： 人体自身生命运动中不断发出的生理信号 被动信号(inactive signal ) 在一定条件（刺激）下产生的生理信号； 信号源不是由生命体自身产生而是外加的
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Active Signal
1.电信号(electrical signal )： 心电图(ECG)、脑电图(EEG)、脑磁图(MEG)、 眼电图(EOG)、肌电图(EMG)、胃电图（EGG） 2.非电信号(non-electrical signal )： 心音(PCG)、血压(blood pressure)、 体温(body temperature)、 各种生化信号(biochemical signal)
心电图(ECG)：electrocardiogram 脑电图(EEG)：electroencephalogram 脑磁图(MEG)：magnetoencephalogram 眼电图(EOG)：electrooculogram 肌电图(EMG)：electromyogram 心音图(PCG) : phonocardiogram 胃电图(EGG): electrogastrogram
Inactive Signal
1.诱发电位 Evoked Potential,EP 视觉诱发电位 Visual Evoked Potential, VEP 听觉诱发电位 Auditory Evoked Potential, AEP 体感诱发电位 Somatosensory Evoked Potential, SEP 事件相关电位 Event-related Potential, ERP 2.医学图像 Biomedical Image 超声图像 Ultrasound Image X-射线图像 X-ray Image 计算机断层成像Computed Tomography,CT 核磁共振成像 Magnetic Resonance Imaging,MRI 正电子发射断层成像 Positron Emission Tomography,PET 单光子发射断层成像 Single Photon Emission Tomography,SPECT
Examples
ECG
Electrocardiography is the interpretation of the electrical activity of the heart over time captured and externally recorded by skin electrodes. It is a noninvasive recording produced by an electrocardiographic device.
12 Lead ECG
Ⅰ,Ⅱ,Ⅲ: limb leads(肢体导联) aVR, aVL, and aVF ：augmented limb leads V1~V6:precordial leads
"ECG- simplified. Aswini Kumar M.D". LifeHugger.
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Waves and intervals
Image showing a patient connected to the 10 electrodes necessary for a 12-lead ECG
Schematic representation of normal ECG
Application
Cardiac murmurs 心脏杂音 Syncope or collapse晕厥或衰竭
P：心房除极； QRS：心室除极； S-T：心室肌细胞动作电位的 平台期。
Dysrhythmias 心律不齐 myocardial infarction心肌梗塞 Fetal Electrocardiogram (FECG)
Monitoring the baby's heart
Animation of a normal ECG wave
MECG
EEG
EEG is the recording of electrical activity along the scalp produced by the firing of neurons within the brain the recording of the brain's spontaneous electrical activity over a short period of time
EEG
Computer Electroencephalograph Neurovisor-BMM 40
Scalp EEG activity shows oscillations at a variety of frequencies These oscillations represent synchronized activity over a network of neurons
oscillations in EEG
An early EEG recording, obtained by Hans Berger in 1924. The upper tracing is EEG, and the lower is a 10 Hz timing signal.
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EEG
Clinical use the diagnosis of in the case of epilepsy, as epileptic activity can create clear abnormalities on a standard EEG study the diagnosis of coma, encephalopathies, and brain death. used to be a first-line method for the diagnosis of tumors, stroke and other focal brain disorders
Epileptic wave
Spike wave and sharp wave
MEG
a technique for mapping brain activity by recording magnetic fields produced by electrical currents occurring naturally in the brain, using arrays of SQUIDs (superconducting quantum interference devices)
MEG system
Triple sensor element manufactured on silicon chip女用站式小便器
Origin of the brain's magnetic field. The electric current also produces the EEG signal .
时规带
MEG vs. EEG
Magnetic fields are less distorted than electric fields by the skull and scalp, which results in a better spatial resolution of the MEG. Scalp EEG is sensitive to extracellular volume currents produced by postsynaptic potentials. MEG primarily detects intracellular currents associated with these synaptic potentials because the field components generated by volume currents tend to cancel out in a spherical volume conductor. MEG is reference-free, while scalp EEG relies on a reference that, when active, makes interpretation of the data difficult.
校园网管理系统MEG use in the field
Focal epilepsy
localizing the cortex for surgical planning in patients with brain tumors or intractable epilepsy
Fetal MEG
study cognitive processes such as vision, audition and language processing in fetuses and newborns
multiple sclerosis, Alzheimer's disease…
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肌电信号（EMG）
Electromyography (EMG) is a technique for evaluating and recording the electrical activity produced by skeletal muscles. The electrical source is the muscle membrane potential of about -90 mV. Measured EMG potentials range between less than 50 μV and up to 20 to 30 mV, depending on the muscle under observation. Typical repetition rate of muscle motor unit firing is about 7–20 Hz, depending on the size of the muscle
肌电信号（EMG）
辐照灭菌设备
two kinds of EMG
surface EMG intramuscular (needle and fine-wire) EMG
Applications of EMG
a diagnostics tool for identifying neuromuscular diseases, assessing low-back pain, kinesiology, and disorders of motor control a control signal for prosthetic devices such as prosthetic hands, arms, and lower limbs
胃电EGG
心音图(PCG)
Measures muscle activity related to the stomach and abdominal region. Measured from a baseline reading containing a regular rhythm. In a normal subject a current increase is observed after a meal. Still an early experimental procedure because it has yet to become a standard medical procedure.
Recording of the sounds made by the heart during a cardiac cycle. The sounds are thought to result from vibrations created by closure of the heart valves
胃电EGG
October 14, 1921
First recording of Electrogastrogram Scientists begin to discover changes due to specific stimuli such as stress and anxiety Use EGG to measure gastric emptying
耳声发射信号：(Otoacoustic Emission，OAE) a sound which is generated from within the inner ear.
spontaneous otoacoustic emissions (SOAEs) which can occur without external stimulation, evoked otoacoustic emissions (EOAEs) which require an evoking stimulus.
留言板制作Recent research has shown that improving quality of life will improve gastrointestinal disease.
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