Introduction to Electrical Measurements in Radiology PDF

:Introduction to Electrical Measurements in Radiology Dr. Ehab Hegazy 1 Introduction to Electrical Measurements Electrical measurements are fundamental in radiological and radiotherapy devices for monitoring, control...

:Introduction to Electrical Measurements in Radiology Dr. Ehab Hegazy 1 Introduction to Electrical Measurements Electrical measurements are fundamental in radiological and radiotherapy devices for monitoring, control, and diagnosis. These measurements ensure the safety and performance of diagnostic tools like X-rays, CT scanners, MRIs, and radiation therapy equipment. 2 Importance of Electrical Measurements in Radiology Accuracy and Precision: Electrical measurements ensure the proper functioning of radiological devices. Ensuring that diagnostic equipment provides clear, precise images. Ensuring the correct radiation dose is delivered in therapy. Patient Safety: Monitoring electrical parameters prevents equipment malfunction and ensures the safe delivery of treatments 3 Basic Electrical Quantities in Radiology Voltage (V): Electrical potential difference across components, important for powering imaging equipment.(volts) Current (I): The flow of electric charge, measured in amperes (A). Critical for operating X-ray tubes and MRI coils. Resistance (R): Opposition to current flow, measured in ohms (Ω). Plays a key role in maintaining equipment efficiency. Power (P): Energy consumption of devices, measured in watts (W), essential for understanding device load. 4 Measurement Instruments Used in Radiology Multimeter: Measures voltage, current, and resistance in diagnostic machines (X-ray, CT). Oscilloscope: Visualizes electrical signals in real time, used for detailed analysis of electronic systems. Electrometer: Measures very low electrical currents and voltages, essential for radiation dosimetry. Power Meter: Monitors the power consumption of imaging devices like MRI machines and linear accelerators. 5 Electrical Measurements in Diagnostic Imaging X-ray Machines: Voltage and current measurements are crucial to control the quality of X-ray beams. CT Scanners: Accurate voltage measurements ensure image clarity and patient safety by controlling X-ray intensity. MRI Systems: Magnetic fields and radiofrequency (RF) signals are monitored using precise electrical measurements to maintain imaging accuracy. 6  Instruments The instruments is used to Measure, Record, and Control process variables.  Properties of intelligent instruments? Better control higher efficiency lower energy less time higher quality cost effective.  A measuring system : provide information about the physical value of some variable being measured. Elements of a Measurement System  1- Sensor sensor is a device that detects and responds to some type of input from the physical environment. The input can be light, heat, motion, moisture, pressure. The sensor converts these physical changes into signal that can be measured  Classification of Sensors The Sensor can be classified as Based on Power Requirement Active Sensors: These Sensors require an external excitation signal or power source to work. Laser radar Passive Sensors: These Sensors do not require any external power source and it can directly generate the output response. Barometer resistor capacitor Tld 12  Types of sensor Temperature sensors Accelerometer sensors Radiation sensor Gas sensors Optical sensors Touch sensors 13 14  2-Variable conversion elements Are needed where the output variable of a primary sensor is in an inconvenient form and has to be converted to a more convenient form. Scintillation detector In some cases, the primary sensor and variable conversion element are combined; this combination is known as a transducer.* 3-Signal processing elements Signal processing elements exist to improve the quality of the output of a measurement system. electronic amplifier which amplifies the output of the primary transducer or variable conversion element, thus improving the sensitivity and resolution of measurement. This element of a measuring system is particularly important where the primary transducer has a low output. In some devices, signal processing is incorporated into a transducer, which is then known as a transmitter.*  4- Signal transmission Transmit the signal to some remote point and second to display or record the signal The signal transmission element has traditionally consisted of single or multicored cable., which is often screened to minimize signal corruption by induced electrical noise. However, fiber-optic cables are being used in ever-increasing numbers in modern installations, in part because of their low transmission loss and imperviousness to the effects of electrical and magnetic fields. Difference between Optical Fiber and Coaxial Cable Both Optical fiber Cable and Coaxial Cable are the types of guided media. Any Questions? 2 5