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gregorysawicki43
02-20-2008, 08:38 AM
Hello listservers;
As promised, here are the responses to my Survey of Ultrasound Systems.
Cheers
Greg S.

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1. STUART MILLER, Brunel University

We currently use the MEGAS GPX from ESAOTE. I have attached the
brochure for it with all the contact information. We have had this a
number of years, and as such, there are probably numerous other
machines that you can acquire. A few observations I would like to
address are:

1 - probe width - we currently use a 50 mm probe. We are just able to
achieve constant observation of the MTJ during movements for both the
tibialis anterior, and the Gastrocnemius medialis. However, it leads
to a long process during preparation when trying to locate the optimal
position for the probe. A bigger probe is highly recommended (up to
100 mm), however these are expensive, and not very common.

2 - connection to the subject - I have found that using a few straps
of zinc oxide tape to attach the probe to the leg, following my an
elastic bandage (commonly used for support following sports injuries)
is very effective, and results in minimal, if any, movement of the
probe.

Our machine is connected to a video recorder so our data is extracted
at 25 Hz. Our machine can achieve 28 Hz, so using the video recorder,
we don't lose much. I think you can probably get higher rates now
though. Most research to date has been done using this approximate
rate of data collection.

If you're hoping to look at locomotion overground, think about the
process of keeping the unit alongside the subject. If using on a
treadmill, I would recommend validation on using this. We are about to
start comparing treadmill and overground actions of the tibialis
anterior, so will hopefully have some idea in the near future.

Hope this has been of some help. Feel free to contact me if you want
anymore help.
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2. GLEN LICHTWARK Griffith University

The machine that you should choose depends a lot on what measures you
want to make. The following are the details of the machine we have
used in the past -

1. What you use ultrasound to measure: Muscle fascicle length changes,
gastroc/Achilles MTJ position, 3D reconstructions of whole
muscles/tendons

2. Company and Model # of your system (with mailing
address/e-mail/phone contact info if possible) : Telemed, Lithuania
(www.telemed.lt). We use the Echoblaster 128 External and hook this to
a standard laptop via USB 2.0. The LogicScan 128 is a better machine
as it also has doppler function.

3. Probe Type (e.g. Linear, # of elements) : a. Linear Veterinary
Probe (LV7.5/60/96Z) 96 Elements. b. Linear Standard Probe
(HL9.0/60/128Z) 128 Elements

4. Probe Scanning Frequency Range (and what setting you prefer to use)
a. 5-8MHz (depends on function, typically 6MHz for muscle and higher
for tendon) b. 5-10MHz

5. Probe Dimensions: Both probes have a field of view of 60mm

6. Depth and Width Resolution: The software produces 512 x 512 pixel
images, but the actual image you get depends on the depth at which you
are scanning. If you scan to a depth of 65mm, this pretty much fills
the 512x512 output. There is no compression in the x and y directions,
unlike the analog video output that comes from many machines.

7. How data is output and at what frame rate (e.g. USB 50 Hz): USB
2.0. Frame rate can be set. Max frame rate depends on many things like
scan depth, number of focal points and further digital processing. It
is possible to run up to 120fps, although for most muscle imaging we
do we set it up so the refresh rate is 60-80fps and record at 50fps.

8. Cost of the system: This depends on the supplier and which probe
you buy. These machines are very cheap compared to some, in Australian
dollars approx $7200 for the machine, $2600 and $4200 for probes a.
and b. respectively.

9. Any general recommendations/feedback/ words of wisdom you would
like to share: For dynamics imaging it is pretty much essential to
buy the veterinary type probe as this can be strapped to the leg quite
easily and moves very little with respect to the leg. However the
other probe produces nicer images and can be used during more 'static'
contractions (e.g. isometric). Telemed have also modified our machine
to produce an output signal which signifies when the software is
recording to the buffer.... this is very useful for triggering the
collection of other devices (e.g. motion analysis, force data etc).
This costs a little extra to make the modification.

We have also looked at other more expensive machines. The biggest
difficulty with most of these is synchronising with other systems. The
Terason machines (www.terason.com) produce nice images and you can
hijack the ECG trace to synchronise systems. They don't sell
veterinary probes but do have some 'sidefire' probes which are
similar. Unfortunately the field of view of many of these probes is
rather small (