Instrumentation Flashcards
(17 cards)
Electromyography (EMG)
How it Works: EMG measures the electrical activity produced by skeletal muscles.
Uses in Speech Pathology: EMG is utilized to assess and monitor muscle activity during speech and swallowing, aiding in the diagnosis and treatment of disorders like dysphagia and speech motor impairments.
Advantages: Non-invasive, provides real-time data, useful for biofeedback therapy.
Disadvantages: Uncomfortable, hard to know if the target muscle is actually being measured, placement of electrodes is of the utmost importance
Respiratory inductance plethysmography (RIP)
How it Works: RIP involves placing elastic bands with embedded sensors around the chest and abdomen to measure respiratory movements by detecting changes in inductance as the chest and abdomen expand and contract.
Uses in Speech Pathology: Helps in evaluating respiratory patterns during speech and swallowing, essential for patients with respiratory or swallowing disorders.
Advantages: Non-invasive, allows for continuous monitoring, provides data on respiratory effort and timing.
Disadvantages: May be uncomfortable for patients, sensitive to movement artifacts, requires proper calibration.
Stroboscopy
How it Works: Uses a pulsing light to simulate movement at a rate slower than the actual rate of movement of the object being imaged
Uses in Speech Pathology: Assists in diagnosing voice disorders by allowing visualization of vocal fold vibration patterns.
Advantages: Provides detailed images of vocal fold function, helps in assessing voice disorders.
Disadvantages: Requires patient cooperation, may not capture high-frequency vibrations accurately, cannot capture disordered voices.
High-speed laryngeal imaging
How it Works: Utilizes high-speed cameras to capture rapid movements of the larynx during speech or swallowing.
Uses in Speech Pathology: Enables detailed analysis of laryngeal dynamics, aiding in the diagnosis and treatment of voice and swallowing disorders.
Advantages: Captures rapid laryngeal movements, provides high-resolution images. The accuracy with which even highly irregular vibration of the vocal folds can be imaged
Disadvantages: Expensive equipment, image sharpness is less than stroboscopy
Videokymography
How it Works: Based on the acquisition of images at a very rapid rate, but does not image the entire area of the vocal folds; typically, the middle of the vocal folds, where vibratory amplitude is widest, is selected for scanning
Uses in Speech Pathology: Analyzes vocal fold vibration dynamics, useful in assessing voice disorders.
Advantages: True cycle-to-cycle imaging of vocal fold vibration, less expensive than high-speed cameras
Disadvantages: Limited to viewing a single line, may miss complex vibratory patterns. The visual image is not intuitive; the images are in black and white, and it must be coupled with either stroboscopy or high-speed video to obtain complete visualization of the vocal folds
Photoglottography
How it Works: Provides information about the relative size of the glottal opening; measures the amount of light passing through the vocal folds during each vibratory cycle
Uses in Speech Pathology: Assesses vocal fold contact and glottal closure patterns.
Advantages: Non-invasive, provides real-time data.
Disadvantages: Provides information only about the relative glottal area, not the absolute or true area, invasive, lack of reference confounds interpretation of the waveform, the light sensor may not accurately register the light transmitted through the glottis due to vocal tract movement
Electroglottography (EGG)
How it Works: Provides a waveform that has been shown to correspond to the relative contact of the vocal folds during vibration. A pair of surface electrodes that are placed on the outside of the neck over the left and right sides of the thyroid cartilage
Uses in Speech Pathology: Evaluates glottal closure patterns and vocal fold contact.
Advantages: Non-invasive, provides real-time data, useful for biofeedback therapy.
Disadvantages: Sensitive to skin impedance, may require proper electrode placement.
X-rays
How it Works: X-rays use electromagnetic radiation to create images of the internal structures of the body. Some energy is absorbed, and some passes through (the passing through allows us to see what’s inside the body)
Uses in Speech Pathology: Historically used to study articulatory movements; however, due to radiation exposure, its use is now limited.
Advantages: Relatively low-cost.
Disadvantages: Noninvasive, but not harmless (damaging to human tissue)
Takes a 3D image and collapses it into a 2D plane
Different types of tissues with similar densities cannot be distinguished from one another
Computed tomography (CT)
How it Works: CT scans use X-ray technology to create detailed cross-sectional images of the body using a narrow x-ray beam that rotates around the body.
Uses in Speech Pathology: Assists in visualizing anatomical structures, particularly in complex cases.
Advantages: Tissues of similar density can be distinguished because of the narrow x-ray beam, and the borders of the tongue and other tissue structures are imaged more clearly in the CT than conventional x-ray because of the composite image created from multiple angles
Disadvantages: Slow scanning speed (too slow for speech)
Scanning angles are limited to transverse and oblique
Far greater cost than conventional radiography
Very high x-ray dosage
Magnetic resonance imaging (MRI)
How it Works: MRI uses strong magnetic fields and radio waves to generate detailed images of internal structures.
Uses in Speech Pathology: Visualizes soft tissue structures, useful in assessing neurological aspects of speech and swallowing.
Advantages: No radiation exposure, provides high-resolution images. Has provided a lot of information:
- Postures of the vocal tract
- Effect of vocal tract postures on voice quality
- Lifespan changes in vocal tract size
Disadvantages: Resolution (good, but not as clear as a CT scan)
Scan rate
MRI slides are wider than a CT, so if there are structures not separated by that much, they’ll be squished together
Requires the person to lie in a tube
Noisy
Ultrasound
How it Works: Ultrasound uses high-frequency sound waves to create images of internal structures.
Uses in Speech Pathology: Assesses tongue movement and positioning during speech.
Advantages: Non-invasive, real-time imaging, portable. The ability to image movement without much difficulty
Disadvantages: The large number of data points obtained with the scan
Identifying the tongue contour with clarity
Identifying specific location points on the tongue
Inability to image the tongue tip
Point-tracking
How it Works: Involves tracking specific points on the articulators using various imaging techniques.
X-ray microbeam
How it works: A very narrow radiation beam is focused upon tiny gold pellets affixed to the articulators, allowing for clearer
movement
Uses in Speech Pathology: articulation
Advantages: Can track up to 1,000 pellet positions per second (so it can track the speed movements of the articulators properly for speech production)
Disadvantages: Pellets may interfere with natural tongue movement
Complexity and expense of x-ray microbeam instrumentation
Though minimized, there is still x-ray exposure
Electromagnetic midsagittal articulography (EMMA)
How it works: Detects the position and orientation of the articulators in the midsagittal measurement plane by measuring electromagnetically induced currents in receiver coils placed around the head
Uses in Speech Pathology: Articulation - Used to track the movements of the lips, soft palate, tongue, and mandible during speech production
Advantages: More than one articulator can be tracked simultaneously, and high velocity movements can be tracked accurately
Disadvantages: Only points are measured, not whole structures, and kinematic data can be obtained only from the midline points on the tongue, lips, or jaw
Optoelectronic tracking
How it works:
Uses in Speech Pathology: Used to assess stability, velocity, and displacement of articulators in children
Advantages: The ability to record kinematic data in 3D
Disadvantages: The LEDs must be visible to the recording sensors, and so tongue movement cannot be measured using this instrumentation (but it is useful for lip and jaw movement tracking)
Strain gauges
How it works: measures the amount of strain
Uses in Speech Pathology: can measure movements of the lip and jaw
Electropalatography
How it works: Uses an array of touch-sensitive electrodes embedded in a thin acrylic palate called a pseudopalate
Uses in Speech Pathology: Records the location and timing of the contact between the tongue and the palate during speech production
Advantages: Unique information provided about articulation, safety.
Disadvantages: Information is acquired only when the tongue is in contact with the palate (so, useful for complex consonants, but not so much for vowels)
