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MEDICAL ELECTRONICS. Mr. DEEPAK P. Associate Professor ECE Department SNGCE. UNIT 1. Introduction to Human Physiological Systems and Transducers. Objective. At the end of this Unit You will learn Physiological Systems of human body Bio medical Transducers and Electrodes.
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MEDICAL ELECTRONICS Mr. DEEPAK P. Associate Professor ECE Department SNGCE
UNIT 1 Introduction to Human Physiological Systems and Transducers
Objective At the end of this Unit You will learn Physiological Systems of human body Bio medical Transducers and Electrodes
Biomedical Engineering • Biomedical Engineering is the application of engineering principles and design concepts to medicine and biology • The biomedical engineering provides electrical, electronic, electro-optical, and computer engineering supporttoclinical and biomedical applications. • Biomedical Engineering improves the field of healthcare diagnosis, monitoring and therapy.
Biomedical Instruments • Classification of Biomedical Equipments • Diagnostic equipment • Therapeutic equipment • Clinical equipment • Laboratory equipment
Components in Man – Instrument system Control feedback Signal conditioning equipment Transducer Display Stimulus Transducer Transducer Recording , data processing and transmission of data
Man – Instrument system • Measurement in biomedical instrumentation can be divided in to two • VIVO • Measurement is made on or within the human body • Eg . Device inserted in to the blood stream to measure PH of blood • VITRO • Measurement is performed outside of the body. • Eg . Measurement of blood PH from blood samples.
Sources of Bioelectric potentials • The systems in the human body generate their on monitoring signals when they carry out their functions. • These signals provide useful information about their function. • Bioelectric potentials are actually ionic voltages produced as a result of electro chemical activity of certain cell. • Transducers are used to convert these ionic potentials in to electrical signals
Resting and Action potentials • Certain types of cells within the body , such as nerve and muscle cells are encased in a semi permeable membrane. • This membrane permits some substances to pass throughwhile others are kept out. • Surrounding the cells of the body are the body fluids • These fluids are conductive solutions containing charged atomsknown as ions
Resting potentials • The principle ions are sodium(Na+) Potassium(K+) and chloride(C-) • The membrane of excitable cells permit entry of Potassium(K+) and chloride(C-) ions but blocks the entry of sodium(Na+) ions. • So inside the cell is more negative than outside cell • This membrane potentials is called Resting potentials • This potential is measured from inside the cell with respect to body fluids. • So resting potential of a cell is negative.
Resting potentials/Polarization • This resting potential ranging from -60mv to -100 mv. • Cell in the resting state is called polarized cell. Cell Membrane V -70 mV Ground
Depolarization of cell • When a cell is exited, the membrane change its characteristic. • The sodium ions are rushed in to the cell. • At the same time potassium ions try move from inside. • After a equilibrium state is reached, the sodium is moved back to outside
Depolarization of cell Na+ K+ Cell Membrane K+ Na+ Na+ K+ K+ K+ Na+ K+ Na+ K+ K+ Na+ Na+ Na+
Action potentials Cell Membrane 20 mV V Ground
Re Polarization • Cell comes from de polarized state in to polarized state is called Re polarization. Cell Membrane V -70 mV Ground
Propagation of Action potentials • When a cell is exited and generates an action potentials ionic currents to flow. • This process excite neighboring cells or adjacent area of the same cell
Physiological systems of human body • In simple terms "Human Physiology" is the study of the body and its functions in each of the different systems in any living body. Input System Output
Physiological Systems in the Human body Vision Speech Appearance Hearing Behavior Smell Expired air Taste INPUTS Body movements Inspired air Tactile sensation OUTPUTS Liquid intake Liquid wastes Solid wastes Food intake
Physiological systems of human body • There are 11systems in the body: • The Skeletal System Bones & joints • Muscular System Skeletal muscle • Nervous SystemBrain, spinal cord & nerves • Endocrine System Hormone-producing cells & glands • Cardiovascular System Blood, heart & blood vessels • Respiratory System Lungs & airways • Digestive System Organs of the gastrointestinal tract • Urinary System Kidneys, bladder and ureters • Reproductive System Male & female reproductive organs • The Integumentary System The skin & derived structures • Lymphatic & Immune System Lymphatic vessels & fluid
Physiology • Physiology can be classified in to • Cell Physiology • Study of cells • Patho Physiology • Pathological Functions • Circulatory Physiology • Study of blood circulation • Respiratory Physiology • Study of breathing organs
Cardio Vascular system • Cardio vascular system can be viewed as closed hydraulic system with 4 chamber pump. • Cardio Vascular system is mainly used for transportation of oxygen, Carbon dioxide, numerous chemical compounds and the blood cells. • Pump-----Heart • Flexible tubes---Blood vessels
Cardio Vascular system • In some part of the system diameter of the arteries are changed to control pressure. • Pump(heart) is a isolated two stage synchronized chamber • The first stage is to collect blood from the system and pump it in to 2nd stage. • The second stage then pump these blood to the system
Heart & Valves Bicuspid/ Left Atrio-ventricular valve Right Atrio-ventricular valve
Heart Layers • Heart wall consists of three layers • Pericardium • Outer most layer, keeps outer surface moist, prevents friction • Myocardium • Middle layer, Main muscle of heart, made up of short cylindrical fibres • Endocardium • Inner layer of heart, Provides smooth lining for blood flow
Heart Valves • Heart has 4 valves • Tricuspid/Right Atrio-Ventricular valve • Between Right A and V, Prevents blood flow from right V to A • Bicuspid/ left Atrio-Ventricular valve • Between left A and V, Prevents blood flow from left V to A • Pulmonary valve • At right ventricle, It has 3 cusps • Aortic Valve • Between left ventricle and aorta, It has 3 cusps
Cardio Vascular System • One of the two stage pump(Right side)collect fluid from the system and pump it through oxygenation system(Lungs). • Other side pumpreceives blood from oxygenation system(Lungs)andpump blood to main hydraulic system. • Blood act as communication and supply network for all parts of the body
Cardio Vascular system • Fluid contains fuel suppliers andwaste particles are transported to destination. • Fluid contain mechanism for rejecting foreign elements and mechanism for repairing small system puncture. • Sensors are provided to detect the changes in the need of suppliers, the build of waste materialandout-of- tolerance pressurein the system known as chemoreceptors, Pco2 sensorsand baroreceptorsrespectively.
Cardio Vascular Circulation • The blood is carried out to the various parts of the body through blood vessels. • There are three types of blood vessels • Arteries--- Thick, Carries oxygenated blood • Veins--- Thin, De-oxygenated blood • Capillaries---Smallest, Last level of blood vessels, 800000 km of capillaries
Cardio Vascular Circulation • Heart pumps blood through the pulmonary circulation to the lungs and through the systemic circulation to the other parts of the body. • Pulmonary circulation • Systemic circulation • In pulmonary circulation, venous blood(de-oxygenated) flows from right ventricle through pulmonary artery to lungs . • The arterial( oxygenated) blood flows to left atrium through pulmonary veins. • In systemic circulation blood flows from left auricle to left ventricle and it is pumped to aorta and its branches
Respiratory systems • It is the Pneumatic system. • A system that work with air pressure. • An air pump(diaphragm) which alternatively create negative and positive pressures in a sealed chamber(Thoracic cavity). • Thoracic cavity sucked air in to and forced out to two elastic bags(Lungs). • The lungs are connected to the external environment through a pass way (nasal cavities, pharynx, larynx, trachea, bronchi and bronchioles)
Respiratory systems • At one point , this passage is common with the tube that carries liquid and solids to stomach. • A special valving arrangement interrupts the respiratory system whenever solid or liquid passes through the common region. • The passage divides to carry air in to each bag. • In each bag , it is sub divided many times to carry air in to and out of each of many tiny air spaces(pulmonary alveoli).
Respiratory systems • In case of nasal blockage , air input can be taken from mouth. • Oxygenis taken from the air and transferred in to blood. • Cabondioxide is transferred from blood to air. • The system has a number of fixed volumes and capacities.
Respiratory systems • Tidal volume • The volume inspired and expired during each normal breath • Inspiratory reserve volume • Additional volume that can be inspired after a normal inspiration. • Expiratory reserve volume • Additional volume that can be expired after a normal expiration.
Respiratory systems • Residual volume • Amount of air remaining in the lungs after all possible air has been forced out. • Vital capacity • Tidal volume+ Inspiratory reserve volume+ Expiratory reserve volume
Blood purification in the human body • The overall functioning of our body heavily depends on the proper functioning of our blood. • We take toxins into our body daily and these toxins disrupts the functions of our internal organs. • Regular detoxificationof our blood is important • Detoxifying the blood and body helps to remove harmful toxins from our body and improve the functioning of our vital organs such as the kidney and liver
Blood purification in the human body • When our body has too much toxins, our vital organs start to get damage and under-perform and we start to develop symptoms of allergies, low immunity, headaches, fatigue and several other health related problems. • The lungs help remove carbon dioxide, the kidneys remove water-soluble waste and the liver removes fat soluble wastes and many other impurities from the blood.
Blood purification by lungs • The un oxygenated (unpurified) blood comes into right atrium of heart by superior and inferior vena-cava which then passes to right ventricle, then to lungs by pulmonary artery. • In lungs this blood gets oxygenated (purified) which then goes into left chamber of heart from which blood is passed to aorta and then circulatedto whole body