MEDICAL ELECTRONICS Mr. DEEPAK P. Associate Professor ECE Department SNGCE MEDICAL ELECTRONICS Mr. DEEPAK P. Associate Professor ECE Department SNGCE DEEPAK.P DEEPAK P

SNGCE UNIT 3 ECG, EMG, Telemetry DEEPAK.P DEEPAK P

EEG DEEPAK.P

Electroencephalography (EEG) Electroencephalography (EEG) is the recording of electrical activity along the scalp. EEG measures voltage fluctuations resulting from ionic current flows within the neurons of the brain. Electroencephalogram (EEG) was first measured in humans by Hans Berger in 1929. EEG is most often used to diagnose epilepsy, which causes abnormalities in EEG readings. DEEPAK.P

Electroencephalography (EEG) DEEPAK.P

Electroencephalography (EEG) It is also used to diagnose sleep disorders, coma, and brain death Among the basic waveforms are the alpha, beta, theta, and delta rhythms. Alpha waves occur at a frequency of 8 to 12 cycles per second in a regular rhythm. They are present only when you are awake but have your eyes closed. Usually they disappear when you open your eyes or start mentally concentrating. DEEPAK.P

Electroencephalography (EEG) Beta waves occur at a frequency of 13 to 30 cycles per second. They are usually associated with anxiety, depression, or the use of sedatives. Theta waves occur at a frequency of 4 to 7 cycles per second. They are most common in children and young adults. Delta waves occur at a frequency of 0.5 to 3.5 cycles per second. They generally occur only in young children during sleep. DEEPAK.P

Electroencephalography (EEG) . DEEPAK.P

Electroencephalography (EEG) . DEEPAK.P

Electroencephalography (EEG) . DEEPAK.P

Evoked Potentials . DEEPAK.P

Electroencephalography (EEG) EEG machine consists of the following components 1- Electrodes. 2- Amplifiers. 3- Filters. 4- Recording unit. DEEPAK.P

Analog EEG DEEPAK.P

Digital EEG DEEPAK.P

EEG Electrodes DEEPAK.P

EEG Electrodes There are two system of electrode placement: 1- 10-20 international system: includes 21 electrodes. 2- 10-10 international system: includes 64 electrodes. DEEPAK.P

EEG Electrodes DEEPAK.P

EMG DEEPAK.P

Electromyogram (EMG) 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 An Electromyograph detects the electrical potential generated by muscle cells when these cells are electrically or neurologically activated Measured EMG potentials range between less than 50 μV and up to 20 to 30 mV, depending on the muscle under observation. DEEPAK.P

Electromyogram (EMG) An electromyogram (EMG) measures the electrical activity of muscles at rest and during contraction. Nerve conduction studies measure how well and how fast the nerves can send electrical signals. Body temperature can affect the results of this test. DEEPAK.P

Electromyogram (EMG) DEEPAK.P

Electromyogram (EMG) DEEPAK.P

Electromyogram (EMG) DEEPAK.P

Electromyogram (EMG) EMG is used clinically for the diagnosis of neurological and neuromuscular problems. There are two kinds of EMG in widespread use: Surface EMG Intramuscular (needle and fine-wire) EMG. A surface electrode may be used to monitor the general picture of muscle activation To perform intramuscular EMG, a needle electrode or a needle containing two fine-wire electrodes is inserted through the skin into the muscle tissue. DEEPAK.P

Electromyogram (EMG) DEEPAK.P

Electromyogram (EMG) DEEPAK.P

Simple Block diagram (EMG) DEEPAK.P

pre-amplifier DEEPAK.P

Properties of an ideal pre-amplifier High common mode rejection ratio Very high input impedance Short distance to the signal source Strong DC signal suppression DEEPAK.P

Analog EMG Block diagram DEEPAK.P

Digital EMG Block diagram DEEPAK.P

Digital EMG Block diagram DEEPAK.P

Bed -Side Monitor 33 DEEPAK.P

Patient Monitoring In medicine, monitoring is the observation of a disease, condition or one or several medical parameters over time. It can be performed by continuously measuring certain parameters by using a medical monitor Transmitting data from a monitor to a distant monitoring station is known as telemetry or biotelemetry. Vital signs (often shortened to just vitals) are used to measure the body’s basic functions DEEPAK.P

Patient Monitoring Vital measurements are taken to help assess the general physical health of a person, give clues to possible diseases. There are four primary vital signs: body temperature, blood pressure, pulse (heart rate), and breathing rate (respiratory rate). DEEPAK.P

Patient Monitoring in ICU DEEPAK.P

Simple Block Diagram of Patient Monitoring Automatic control Patient equipment Computer DBMS Reports Mouse and keyboard Display Transducers Clinician DEEPAK.P

Bed-Side Monitor DEEPAK.P

Measuring Parameters Cardiac monitoring: Electrocardiography Cardiac output Hemodynamic blood pressure and blood flow Respiratory monitoring: Pulse oximetry,Capnography, airway respiratory rate) Blood glucose monitoring Childbirth monitoring Body temperature monitoring DEEPAK.P

Central Monitor 40 DEEPAK.P

Central Monitoring Bedside Monitors Physiological data Hard wire Remote Link From other beds Central Monitor Console DEEPAK.P

Central Monitoring DEEPAK.P

Bio Telemetry 43 DEEPAK.P

Bio-Telemetry The term telemetry is derived from the two Greek terms: “tele” and “metron”, which mean “remote” and “measure”. In general, a physical variable or quantity under measurement, whether local or remote, is called a measurand. Telemetry is a technology that allows the remote measurement and reporting of information of interest to the system designer or operator. Literally, biotelemetry is the measurement of biological parameters over a distance. DEEPAK.P

Elements of Telemetry DEEPAK.P

Elements of Telemetry Transducer or Sensor: Converts the physical variable to be telemetered into an electrical quantity. Signal Conditioner-1: Converts the electrical output of the transducer (or sensor) into an electrical signal compatible with the transmitter. Transmitter: Its purpose is to transmit the information signal coming from the signal conditioner-1 using a suitable carrier signal to the receiving end. DEEPAK.P

Elements of Telemetry The transmitter may perform one or more of the following functions: (i) Modulation: Modulation of a carrier signal by the information signal. (ii) Amplification: As and if required for the purpose of transmission. (iii) Signal Conversion: As and if required for the purpose of transmission. (iv) Multiplexing: If more than one physical variables need to be telemetered simultaneously from the same location, then either frequency-division multiplexing (FDM) or time-division multiplexing (TDM) is used. DEEPAK.P

Elements of Telemetry Receiver: Its purpose is to receive the signal(s) coming from the transmitter (located at the sending end of the telemetry system) via the signal transmission medium and recover the information from the same. It may perform one or more of the following functions: Amplification Demodulation: Reverse Signal Conversion De-multiplexing DEEPAK.P

Elements of Telemetry Signal Conditioner-2: Processes the receiver output as necessary to make it suitable to drive the given end device. End Device: The element is so called because it appears at the end of the system. End device may be performing one of the following functions: Analog Indication: Digital Display Digital Storage Data Processing Closed-Loop Control DEEPAK.P

Subsystems of Telemetry System (a) Measurement Subsystem: It comprises the transducer (or sensor), signal conditioner and the end device, like any conventional measurement system. (b) Communication Subsystem: It comprises the transmitter and receiver along with the transmission medium linking the two, like any communication system. DEEPAK.P

Telemetry Classification Based on Transmission Medium Wire-Link Telemetry or Wire Telemetry Radio Telemetry or Wireless Telemetry DEEPAK.P

Wired Telemetry DEEPAK.P

Elements of Wired Bio-Telemetry(Analog) DEEPAK.P

Elements of Wired Bio-Telemetry(Digital) DEEPAK.P

Elements of Wired Bio-Telemetry DEEPAK.P

Elements of Wireless Bio-Telemetry A typical biotelemetry system comprises: Sensors appropriate for the particular signals to be monitored Battery-powered, Patient worn transmitters A Radio Antenna and Receiver A display unit capable of concurrently presenting information from multiple patients It is two types Short-Range Radio Telemetry Satellite-Radio Telemetry DEEPAK.P

Elements of Basic Wireless Bio-Telemetry DEEPAK.P

Elements of Wireless Bio-Telemetry DEEPAK.P

Wireless Bio-telemetry Transmitter DEEPAK.P

Wireless Bio-telemetry Receiver DEEPAK.P

Elements of Wireless Bio-Telemetry DEEPAK.P

Telemetry Classification Based on Modulation Method DC Telemetry Systems 1. Direct voltage telemetry system 2. Direct current telemetry system AC Telemetry Systems 1. Amplitude modulation (AM) telemetry system 2. Frequency modulation (FM) telemetry system Pulse Telemetry Systems 1. Pulse amplitude modulation (PAM) telemetry system 2. Pulse width modulation (PWM) telemetry system 3. Pulse phase modulation (PPM) telemetry system 4. Pulse frequency modulation (PFM) telemetry system 5. Pulse code modulation (PCM) telemetry system DEEPAK.P

Direct Current Telemetry DEEPAK.P

FM Radio Telemetry DEEPAK.P

Single Channel PWM Telemetry DEEPAK.P

Single Channel PCM Telemetry DEEPAK.P

Portable Telemetry DEEPAK.P

Portable Telemetry DEEPAK.P

Cardiac Tachometer 69 DEEPAK.P

Tachometer Tachometer is generally used for measuring the speed Tachometer can be classified in to Analog Tachometer– It consists of needle and dial Digital Tachometer-- It consists of memory, LCD and LED Contact Tachometer–Sensor is directly contact with rotor Non Contact Tachometer Time/ Frequency measurement Tachometer DEEPAK.P

Tachometer DEEPAK.P

Applications Tachometer It is commonly used in automobiles and machineries. It is used in automobiles to indicate the rotation rate of crank shaft of engine. Used to estimate the traffic speed of vehicles. Used in medical field to measure the heart rate , blood flow rate, respiratory gas flow rate. DEEPAK.P

Cardiac Tachometer It senses the heart beat from finger tip using IR reflection method When heart contracts, the volume of blood in the finger tip decreases. When heart expands, the volume of blood in the finger tip increases. The resultant pulsing of blood volume inside the tip is proportional to heart rate. DEEPAK.P

Cardiac Tachometer IR TX-RX pair is placed in finger tip with close contact. The reflected IR wave is sensed by the circuit. The intensity of the reflected wave is proportional to the volume of blood in the finger tip. DEEPAK.P

Block Diagram of Cardiac Tachometer DEEPAK.P

Cardiac Tachometer DEEPAK.P

IR Sensor DEEPAK.P

Cardiac Tachometer DEEPAK.P

Cardiac Tachometer DEEPAK.P

Cardiac Tachometer DEEPAK.P

Cardiac Tachometer DEEPAK.P

Cardiac Tachometer DEEPAK.P

Cardiac Tachometer DEEPAK.P

Cardiac Tachometer DEEPAK.P

Alarms 85 DEEPAK.P

Comparator Alarm Circuits DEEPAK.P

Alarm Circuits using Cardiac Tachometer DEEPAK.P

Lead Fault Indicator 88 DEEPAK.P

Lead fault indicator DEEPAK.P

Lead fault indicator When a monitor electrode or lead wire comes loose, the appearance of display will be either a base line or 60Hz interface. DEEPAK.P