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Content Reviewed 09/30/2008
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Sonography
Use and Orientation of Ultrasound Equipment |
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Figure 1. Example of proper room setup. |
Using ultrasound equipment including the console,
keyboard and transducer may present a significant risk of musculoskeletal
disorders (MSDs) to the sonographer if not properly arranged. Due to the high cost of
ultrasound equipment, older
equipment may stay in use for some time. Older equipment often has the monitor,
console and keyboard bundled into a single unit, allowing for few adjustments.
In addition, the transducer is generally designed based on diagnostic
performance and not necessarily for ease of use. Newer equipment is much
more adjustable. When replacing this ultrasound equipment, models with maximum
adjustability may help to prevent work-related MSDs.
Using the Transducer and Imaging Supplies
The transducer is the part of the ultrasound
equipment that comes in contact with the patient's skin. It is almost
always handheld and, depending on the application, it may be small or
large. Generally, the transducer is made from a hard, smooth material to
ensure that it can be adequately cleaned. Many procedures require the
sonographer to exert force when pressing the head of the transducer toward
the area of interest. To get the best picture of the affected area, the
sound wave emitted from the transducer needs to be redirected during the
process, often requiring the use of highly repetitive motions. In addition
to the transducer, other items such as gloves and coupling agents may be
necessary to improve the scans and provide sanitary conditions. Use and
placement of these items may create additional hazards.
Potential Hazards
- Use of highly repetitive motions and prolonged forceful hand
exertions often in bent wrist postures when using the transducer. This
increases the risk of injury to the hand, wrist and elbow.
- Exerting force while the forearm is rotated, especially if the wrist
is bent inward (flexed). This increases risk of injuries to the elbow.
- Supporting or moving heavy cables repeatedly or for prolonged
periods of time increases the risk of injury to the shoulder, arm and
wrist.
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- Repeatedly dragging or pulling the transducer cable during
scanning motions creates resistance to transducer movement causing
torque. Torque increases the amount of force the muscles of the
forearms must exert, increasing the risk of injury to the hand, wrist
and elbow. (Figure 2)
- Repeatedly using the thumb to push against the ledge of the
transducer deQuervain’s disease
(tendonitis).
- Resting the elbow or forearm on hard surfaces while scanning may compress nerves
and blood vessels, increasing the risk of numbness and tingling in the fingers.
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Figure 2. The users wrist is bent and the arm is unsupported. The
cord of the transducer creates drag on the transducer and increases
the finger force which must be exerted. |
- Using significant force to expel coupling agent gel,
increasing the risk of injury to the hands, wrist and elbow.
- Stretching and reaching beyond the control panel to access gel
holders or boxes.
- Using gloves that are too small, creating resistance when opening the
hand, requiring additional force.
- Using gloves that are too large, leaving excess material in the palm,
increasing the force needed to close the hand around the tool.
- Reduced tactile response of the fingers when using gloves,
especially when combined with a lubricant. This also increases the
hand force the sonographer must exert to gain adequate control of
the transducer.
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Possible Solutions
- Provide transducers which minimize the risk to the sonographer.
- The transducer should be lightweight and the contact point should be
balanced to minimize the torque on the wrist.
- A design that facilitates a power grip without a stretched and
expanded hand posture.
- A design that allows the wrist to stay in a neutral posture during
many scans.
- A design that minimizes the force which must be exerted. A flange on a long cylindrical handle or a change in
orientation would provide a better power grip.
(Figure 3)
- Transducers should be of an appropriate size for the sonographers if at all
possible.
- The handles should have a slip-resistant surface.
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Figure 3. Operator holding transducer using a power grip. |
- Use arm rests or cushions to support the arm during scans.
This reduces the muscle force needed to hold the arm and any devices
held in the hand.
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- Transducer cables should be supported during the exam. A cable brace
may be used to position cables overhead or along the arm. (Figure 4) Using a cable brace to manage transducer cable to minimize the
amount of force exerted by muscles.
- When using a cable brace, place it on the forearm of the scanning
arm, just below the elbow.
- Port connector permits ease of use, single-handed use, minimizing
the reach, force and necessity of a pinch grip. This does not
interfere with access to equipment or system interaction.
- Trap transducer cable
underneath the strap on the cable brace. Lengthen the amount of cable
between the transducer and the strap so that movement is not
restricted.
- Once the exam is completed, disconnect the cable brace, remove your
glove and take a moment to stretch your hand, arm, shoulder and neck.
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Figure 4. Operator has wrist and forearm supported, hand
comfortably draped around the transducer and cable brace in use,
reducing the torque on wrist.
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- Ensure that the length of cables is appropriate for the procedures
being performed. The cables should be long enough to provide
unrestricted access to all other pieces of equipment after they are
arranged, to minimize the sonographer's awkward posture. However, the
cable should be short enough to minimize the weight, which must be
supported during an exam.
- Ensure transducer holder is easily accessible while keeping the
elbow close to the torso. It should not require much force to remove
the transducer from the holder.
- Always scan while maintaining the arm in front of the
body and abducted (spread) less than about 30 degrees.
- Sonographers should not use the ledge of the tranducer to push
towards
the patient's body. In addition, a standing position should be used,
rather than sitting and pushing from the hips, when scanning bariatric
patients.
- Position yourself as close to the patient as possible to minimize
reach distances.
- Move around the table rather than reaching over the patient.
- Keep the elbows close to the torso and the forearm approximately
parallel with the floor. Reaching up to 20 inches can fatigue the arms
in as little as 7 minutes. [Handbook of Human Factors and Ergonomics,
1997]
- Store all imaging supplies within easy access in the examination
area.
- Use gel bottles with large openings to reduce the force
needed to squeeze and extract gel.
- Use gel bottles small enough in diameter to avoid excessive grip
span.
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- Use gloves that are appropriately sized and as thin as possible, to
minimize resistance. The gloves should be textured to improve tactile function and
reduce force required to grip. "One size fits all" gloves are not
suitable for ultrasound scanning as they do not always provide
proper fit. (Figure 5)
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Figure 5.
Wear gloves that fit and have
textured fingers. Gloves that are too large can slip and reduce the
force. |
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