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| Echocardiography Machine |
The echocardiographic machine's controls are separated into several functional areas. While the specifics may vary from manufacturer to manufacturer or even machine to machine, there are common functions to all echocardiographic machines. The common functional areas are:
- Monitor/Screen (Viewing)
- VCR/DVD/Magneto Optical Drive (Recording)
- Machine Setup
- Analysis
- Keyboard
- Gain (Global, LGC, TCG)
- Microphone
- Ultrasound Modes
- Measuring/Tracing Controls w/ Trackball
- Probe Socket
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| Transesophageal Machine Equipment
and Controls |
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| The Screen |
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| After the echocardiographic machine has been turned on and booted up many of the settings appear on the screen. When referring to the screen, the screen top, screen bottom, screen left, and screen right may or may not refer to the patient's anatomical top (cephalad), bottom (caudad), left and right. The tip of the sector scan is the location of the echocardiographic probe, shown here, at the screen's top. The sector scan is divided into fields. The field nearest to the probe's location is the near field. The field farthest from the probe's location is the far field. Whether the scan is a transesophageal or transthoracic, the screen can be set to be inverted or not inverted. The standard format is to not show an inverted screen, so the anatomy is inverted when comparing transthoracic and transesophageal scans. While other machines will differ in their screen location of the settings and information, these settings are ubiquitous throughout the echocardiographic world. On the screen, in the left upper corner, in this image, the patient's name and institutional information would be displayed. The machine will have a setup area where the patient's name, echocardiographic technologist, echocardiographer and other information could be entered. |
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| Screen Directions |
The Screen |
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Also on the screen is information about the tape/DVD/CD time, gain setting, compress setting, heart rate, and the depth of the sector scan. Some machines will also display the frame rate in this area. |
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| On the screen will be an area signifying the frequency setting for the echocardiographic
probe.
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On the screen is the patient's and the probe's temperature. If the probe become too hot then the probe will shut down to prevent patient thermal injury. Modes that require more energy, such color modes, will increase the temperature more rapidly than lower energy modes.
 During a scan, when you are not looking at the screen, put the probe into freeze mode. Freeze mode will stop the energy flow thru the probe and the local tissues will cool. When returning to the screen, unfreeze the echo probe and the scan can continue. |
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| On the screen should be a graphic signifying the amount of electronic or longitudinal angle of the transesophageal probe. |
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| Also, on the screen is a graphic representing the color map, gray scale map, the center setting (baseline) of the color map, the range of velocities of the color map, and the probe's frequency setting for the color doppler |
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| On the bottom of the screen is the ECG. The ECG should be attached and recorded for all patients. The timing of events and specific measurements should be made during specific times requires the use of an ECG tracing. The sweep speed of the ECG can be changed for more accurate timing of cardiac events.
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| The Monitor |
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| The monitor is an easily overlooked setting, usually getting lost in the various knobs and settings of the echocardiographic machine. The contrast and brightness of the monitor should be set in the normal viewing ambient light prior to the exam. The contrast knob should be set at the midpoint. The brightness knob should be decreased maximally and then slowly increased until the darkest grayscale box barely appears. The contrast and brightness of the monitor are now set. The CRT projects the image via a magnetic field. External magnetic fields may alter the internal magnetic field causing areas on the screen that are blurry or have hue's or tints in them. In the images below increasing the brightness increases the pixel value of all of the pixels. In the operating theatre, the ambient light is very bright. Because of the bright ambient light, the gain is typically turned up so the images can be visualized in the operating rooms. Once those images are viewed in a low ambient light viewing room, the images appear to be too bright. To control this effect, turn up the brightness control as outlined above so the images can be easily seen in the bright-light environment. |
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| The usual setting for the monitor is contrast near 50% and the brightness increased until the darkest gray bar of the gray scale is visible. |
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Brightness High
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Brightness Low
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| Contrast Low |
Contrast High |
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| Setup Controls |
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| The setup area controls the standard settings or presets of the echocardiographic machines. A touch of a button will change the machine from a transesophageal to a transthoracic machine. Also, all of the internal settings or preferences can be set. Selecting the probe socket and probe if multiple probes are connected can also be done here. Setup information about institution, clock, and other information can be input to be displayed on the screen. |
| This area can also contain information about input from monitors, such as an electrocardiogram. intra-arterial monitor, respiratory monitor, or heart sounds, and the settings for the monitor, such as sweep speed and height, for timing events in the cardiac cycle. |
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| Mode Control |
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| Control of the echocardiographic modes can be quite confusing. There are controls of each of the "pure" modes such as 2D, M-Mode, Color Flow Doppler, Continuous Wave Doppler, and Pulse Wave Doppler. Then there are the combination of modes such as Color M-Mode, and Tissue Doppler Interrogation. There is also sub modes of modes such as Color Tissue Doppler. Each of these modes, sub modes, or combination modes has its own set of controls but most of the controls overlap, thereby contributing to the confusion. We will discuss each mode that is selectable in a normal echocardiographic machine. Under each mode or combination of modes the controls will also be covered. |
