Term
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Definition
| Reversible conversion of electrical energy to mechanical deformation |
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Term
| Piezoelectric crystals can be made from: |
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Definition
Naturally occurring crystals (sugar, quartz)
Man-made crystals (quartz-like substances)
Ceramic-based materials – Most Contemporary Transducers
Polymers {Polyvinylidene fluoride (PVDF) |
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Term
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Definition
| A two-dimensional picture of a body radiation source is obtained through the use of radioisotopes. |
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Term
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Definition
| Short wavelength electromagnetic radiation of produced when high-speed electrons strike a solid-state target (radiographic film). |
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Term
| Examples of Scintigraphic Techniques |
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Definition
Thallium treadmill stress test
V/Q scan looking for pulmonary embolus in lungs
PET and CT imaging for tumors or cancer, or PE
Angiogram (or myo-, arterio-, veno-, or lympho-) |
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Term
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Definition
Positron Emission Tomography
Nuclear medical imaging technique
Produces a three-dimensional image of functional processes in the body
Detects radioisotopes, which are introduced into the body on a metabolically active molecule. |
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Term
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Definition
Computer (Aided) Tomography
Uses x-ray technology to create images
Produce multiple images of the body part being examined (from different angles)
Computer joins them together, in cross-sectional views
The images can then be examined on a computer monitor or printed |
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Term
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Definition
| Change a physical property to electrical energy |
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Term
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Definition
| Respond to physical or physiological changes in the body |
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Term
| Three Categories of Signal Conditioners |
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Definition
Amplifiers :Alter the energy level of the signal
Filters: Alter the frequency content of the signal
Signal Processors: Derive (new) information from the (old) signal |
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Term
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Definition
| Alter the energy level of the signal |
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Term
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Definition
| Alter the frequency content of the signal |
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Term
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Definition
| Derive (new) information from the (old) signal |
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Term
Amplification ratio?
called? |
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Definition
output/input
called SENSITIVITY or GAIN |
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Term
| Biological signals are __________ in amplitude |
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Definition
| small, In the microvolt to millivolt range; considered low level signals |
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Term
| Output device signals require __________ amplitudes |
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Definition
| large, In the volts range, 1- 10 volts (or more); considered high level signals |
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Term
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Definition
| In the output signal of a device, distortion caused by the presence of frequencies that are not present in the input signal. |
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Term
| total harmonic distortion (THD): |
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Definition
| When an amplifier is driven with a signal, the output of the amplifier is an amplified version of the input signal plus any distortion of the signal created by the amplifier. All signal processors add distortion. |
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Term
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Definition
| a multiple of the fundamental frequency. For example, a harmonic frequency of 300 Hz developed in a 60-Hz system, is the fifth harmonic (300 Hz / 60 Hz = 5). |
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Term
| The maximum input signal level is called: |
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Definition
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Term
| The maximum output voltage is limited by the __________ __________ __________. |
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Definition
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Term
| Electrical impedance, or simply impedance, describes __________ to sinusoidal alternating (AC) current. |
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Definition
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Term
| Impedance extends the concept of __________ to AC circuits, describing not only the relative amplitude of the voltage and current, but also the relative phases. |
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Definition
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Term
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Definition
Introduced in the amplification process
Inevitable product of electronic components
Measured in either decibels or peak output voltage produced by the amplifier when no signal is applied |
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Term
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Definition
When an amplifier reaches its maximum capacity & cannot amplify any further (or saturation voltage)
The result is a distortion, known as clipping. Only some of the signal is being amplified. Where is the rest of the signal? |
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Term
| __________ filters utilize resistors, capacitors & inductors to operate. |
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Definition
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Term
| filters use computer code to operate. |
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Definition
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Term
| A decibel is a __________ value |
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Definition
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Term
| An important reference value is a change of __________ in any signal power, voltage or current. |
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Definition
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Term
| A decibel (dB) change for: Voltage or Current is calculated as of __________ the ratio. Therefore, a reduction of 3 decibels in voltage or current results in a reduction __________ __________ of the original value |
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Definition
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Term
| A decibel (dB) change for: Power is calculated as __________ of the ratio. Therefore, a reduction of 3 decibels in power results in a reduction __________ __________ of the original value |
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Definition
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Term
| Filters content __________ __________ __________ of a signal |
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Definition
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Term
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Definition
| A filter that passes frequencies above a specified cut-off frequency (fco) |
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Term
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Definition
| A filter that passes frequencies below a specified cut-off frequency (fco) |
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Term
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Definition
| A filter that passes frequencies between two cut-off frequencies, but removes all other frequencies above & below the cut-off frequencies. |
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Term
| Band Reject, or Notch Filter |
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Definition
| A filter that passes frequencies below a cut-off frequency and above a second cut-off frequency but removes all frequencies in-between. |
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Term
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Definition
| filter not functional, or active |
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Term
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Definition
| filter begins to perform function |
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Term
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Definition
filter considered operational, or functional
cut-off frequency (fCO)
-3 Db or 50% or 70.7% of
original signal |
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Term
| A filter is said to be “active in the __________ band” because the frequencies in that range do not have enough energy to perform “__________”. |
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Definition
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Term
| Functional cut-off frequency: |
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Definition
| the point at which the frequency reaches a 3 dB reduction of the original signal amplitude. |
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Term
| A reduction to 70.7% of the signal’s original __________ amplitude. |
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Definition
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Term
| A reduction to 50.0% of the signal’s original __________ amplitude. |
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Definition
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Term
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Definition
| The steepness or slope of signal amplitude reduction |
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Term
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Definition
| Derive NEW information from the signal |
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Term
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Definition
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Term
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Definition
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Term
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Definition
| neon & xenon ionized to plasma |
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Term
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Definition
Access time measured in nanoseconds (10-9)
Temporary RAM (fixed within the circuitry)
This is the CPU or central processing unit
Math, Algebra, and Logical Operators occur here
Solid State components
No moving parts
Nothing to wear out
Enemy is heat generated when processing |
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Term
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Definition
Access time measured in milliseconds (10-3)
Hard drive, thumb or flash drive, external drive
Currently, a rotational device with access arm
Head can “crash” into the hard drive, destroying some or all of your data
Requires dust-free environment
Future secondary storage devices moving toward solid state (no moving parts) but currently expensive |
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Term
| Tertiary (when time is not the issue, volume is) |
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Definition
Extraordinarily massive data storage system
Thousands of CD’s or hard drives
Climate-controlled environment
Extremely slow (10-60 seconds) access time or more
CD or hard drive media storage
Information accessed via robotic arm by electronic request |
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Term
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Definition
Digital Imaging and Communications in Medicine
A standard for handling, storing, printing and transmitting information in medical imaging.
Includes a file format definition and a network communications protocol.
DICOM files can be exchanged between two sites capable of receiving image and patient data in DICOM format, similar to internet but “private”.
Devices include scanners, CPU’s, printers, any form of monitor, and storage devices including CD or DVD.
Media can be in optical or solid-state format.
Modem and Internet transmission / reception in
DICOM format are used for longer distance transfers.
Devices are referred to as being “DICOM compatible”. |
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Term
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Definition
Picture Archiving and Communication Systems
ACS are migrating from radiology reading rooms into cardiology, oncology, operating rooms (OR), emergency rooms (ER), the cath, vascular and echo lab, physicians’ offices and across the healthcare enterprise (for hospital-wide access). DICOM compatible.
3D/4D Advanced Visualization Capability
Richer Image Databases
On-Demand Access to Accurate, Detailed Images and Prior Exam Data
Greater Storage Needs – File Size, Sharing, Distribution |
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Term
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Definition
| Bayonet Neill Concelman connector |
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