BTL – 07p
operating manual & user's guide
page 13
necessary to eliminate even a minimal air gap between the skin, the bag and the emitter head by using
vaseline or paraffin oil, often considered unnecessarily time-consuming.
Ultrasound frequency
Older instruments operate at a fixed frequency, usually 0.8 - 1 MHz. Newer ones have a choice of frequencies.
The level of frequency is determined by the affected tissue’s location (see above). A frequency of 1 MHz for deep
tissues and 3 MHz for superficial tissues is recommended.
Modes of operation
A/ continuous ultrasound - predominantly deep heat generation in tissues. This form of ultrasound is
contraindicated in inflamed areas and in cases where local warming of the tissue is undesirable.
B/ pulse ultrasound - the shortened impulse time is followed by a decreased pulse-to-period ratio - PPR. As
a result, the thermic effect is suppressed. With a PPR smaller than 1:8, an athermic effect can be expected.
The BTL-07p’s impulse time is shown by a proportional number. This number actually represents a fraction, which
expresses a certain part of the ultrasonic emission period. With a pulse frequency of 100 Hz, the period time is 10
ms. A 1:4 PPR means that the impulse lasts 1/4 of the period (2.5 ms). A pause lasts the rest of the period (7.5
ms).
1:8 PPR - the impulse lasts 1.25 ms (1/8 of 10 ms) and the pause 8.75 ms.
With a pulse frequency of 50 Hz, the period is 20 ms long. 1:4 PPR - the impulse time is 5 ms (1/4 of 20 ms),
pause 15 ms. 1:16 PPR - the impulse time is 1.25 ms (1/16 of 20 ms), pause 18.75 ms.
Emitter head size
The emitter head size determines the effective radiating area - ERA 1 cm
2
(small) and 4 cm
2
(medium - although
some producers consider it large). The choice of emitter head size is determined by the size of the application
site. Ultrasound emission to large areas is difficult for the therapist, lasts too long, and the dose is not applied
consistently.
Small ERA 1 cm
2
emitter heads are used either to manage trigger points and scars or to manage small, uneven
surfaces which have to be treated by the subaqual method if the emitter head size is large.
Application time
Individual application times vary. They largely depend on the stage of the disease or condition. In acute states, an
application lasts 3 minutes; in chronic states, 5 minutes. Application time is then extended using a
positive step
method. Application time usually must not exceed 10 minutes. When the application site area is x-times larger
than the emitter head ERA, application time must be prolonged x-times.
The dynamic method should be used.
Intensity
An intensity of 0.5 W/cm
2
is used initially in acute states. In certain cases it is even lower - e.g. in trismus
0.2 W/cm
2
on the spasmodic fibres of m. temporalis. This muscle is situated just below the surface, on the bone.
Since work is usually performed in a close ultrasonic field, a very low intensity is chosen.
In chronic states, a 0.8 - 1.0 W/cm
2
intensity is initially used.
Using a positive step method and paying close attention to the patient’s reactions, the intensity is increased.
Continuous ultrasound intensity must not exceed 2.0 W/cm
2
or a pulse ultrasound intensity of 3.0 W/cm
2
.
It is not recommended to increase two parameters at the same time. If application time is extended, do not
increase intensity. If intensity is increased, do not extend application time.
Procedure frequency
For acute cases: 5 times a week. For chronic cases: 3 times a week. In some cases it is suitable to change the
procedure
frequency during the treatment process (e.g. 3 times a day, 3 times every second day).
Total number of treatments
The total number of treatments varies according to individual circumstances, and can range from a single
application prior to myosceletal surgery to 9 applications over a 3-week period for chronic states.