Intramuscular Heating Rates of a Chattanooga Intelect XT Therapeutic Ultrasound With 3 MHz, 1.0 W/cm2 at Three Depths up to 2.5 cm
Phase: NA
Conditions: Ultrasound Therapy; Complications
Sponsor: North Dakota State University

Intramuscular Heating Rates of a Chattanooga Intelect XT Therapeutic Ultrasound with a 3 MHz 
frequency and 1.0 W/cm2 Intensity at Three Depths up to 2.5 cm. 
 
1-22-19 
 
 

Methods and Procedures Attachment 
Individual subjects will report to the Bentson Bunker Fieldhouse, Room 14. They will be 
instructed to wear appropriate shorts or pants that can be rolled up to expose the gastrocnemius 
(calf) muscle. Upon their arrival to room 14, they will be given a copy of the consent form to 
read and sign. The subject will be given the opportunity to ask questions to the researchers 
regarding the consent form at this time. The subjects will lie prone on a treatment table for 
insertion of the thermocouple and for the ultrasound treatment. A towel will be placed under the 
subjects’ knee as needed for comfort. The 21-gauge flexible, implantable thermocouples (very 
small temperature probes) will be calibrated before the study begins and then will be sterilized in 
MetriCide for at least 12 hours before use. The thermocouples will be inserted into the medial 
side of the gastrocnemius muscle horizontally and parallel to the ultrasound treatment surface at 
depths of 1.0cm, 1.75cm, and 2.5cm. Horizontal insertion of the thermocouples allows the 
ultrasound to be applied without interfering with the thermocouple lead wires. 
The subject will lay prone on the treatment table with the foot and lower leg off of the 
treatment table in a relaxed, comfortable position. The following procedures will be completed 
using universal precautions: 
1.  The investigator will prep the treatment area by having the subject flex the calf to 
determine the proper location for the ultrasound treatment in the middle of the medial 
gastrocnemius muscle belly at its largest girth.  
a. A carpenter’s square with markings along the vertical arm at the three 
experimental depths (1.0, 1.75, 2.5 cm) will be used.  

b. The horizontal arm of the carpenter’s square will be covered in tape. The 
carpenter’s square is then placed just proximal to the treatment mark while the 
level on the horizontal arm is used to maintain a level measure.    
c. Marks will be made on the muscle belly parallel to the marks on the vertical 
axis at 1.0, 1.75 and 2.5 cm depths.  
d. A mark is also made on the horizontal arm tape in line with the treatment 
mark on the medial gastrocnemius. 
 
2. The Terason uSmart 3300 diagnostic ultrasound unit will be used to measure the 
adipose thickness over the treatment area and look for abnormalities in the treatment 
and thermocouple insertion areas. Aquasonic® 100 ultrasound gel will be placed on 
the 15L4 transducer. The transducer with gel will be placed over the mark of the 
treatment area. Once the transducer is in place, the screen will be frozen and the skin 
and adipose thickness will be measured using the caliper tool. 
a. If adipose thickness is greater than 1.0 cm or any tissue abnormalities exist 
that could contraindicate thermocouple insertion, the subject will be excluded. 

3. The thermocouples will be removed from the MetriCide after sterilizing for a 
minimum of 12 hours prior to insertion.  
a. The distal aspect of the thermocouple will be wiped dry with sterile gauze. 
b. A mark with a sharpie will be made on each thermocouple just past the length 
marked on the horizontal arm of the carpenter’s square. This allows the tip of 
each thermocouple to be directly below the treatment site. A second mark will 
be made at 5 cm to make sure the thermocouple does not go too deep into the 
tissue. 
 
c. The distal end of the thermocouple will be wiped clean again using a 70% 
isopropyl alcohol wipe up to the marks and then the thermocouple will be 
wrapped in sterile gauze until it is inserted.  

 
4. The insertion areas will be shaved to remove any body hair (if necessary) and cleaned 
using Betadine.  
a. Once the Betadine dries, 70% isopropyl alcohol will be wiped over the 
insertion area and given time to dry.  
 
5. The subject will be instructed to take two deep breaths, while the researcher lightly 
grasps the gastrocnemius to confirm muscle relaxation.  
a. During the second exhalation, the 1.16 in needle catheter will be placed into 
the subject’s calf at the 1.0 cm depth insertion mark using the level to guide 
the needle in.  The needle will be removed leaving the catheter in the tissue. 
 

b. The thermocouple will be threaded through the catheter to the appropriate 
depth marked on the thermocouple and the catheter will be removed.  
 
c. The thermocouple will be secured using medical tape to keep it from moving.  
d. This procedure will be performed 3 times, with one thermocouple placed at 
each respective depth: 1.0 cm, 1.75 cm, and 2.5 cm.  
6. Each thermocouple will be attached to the Iso Thermex electronic thermometer 
(Columbus Instruments, Columbus, OH), which will measure and record 
intramuscular temperatures from the tips of the thermocouples. 
7. An ultrasound treatment template will be applied at the treatment site and secured 
with tape to maintain consistent treatment size.  
a. This template will be twice the size of the transducer’s Effective Radiating 
Area (ERA). 
 

8. A metronome will be utilized to consistently move the transducer at a rate of 4 cm/s . 
9. The ultrasound treatment will begin once the intramuscular temperature has remained 
the same for a minute. 
10. Each subject will receive one ultrasound treatment at the following parameters:  3 
MHz frequency, 1.0 W/cm2 intensity, and 100% duty cycle using the Chattanooga 
Intelect® Legend XT.  
a. Termination of treatment will result when any of the following occur:  
i. A 15-minute treatment time is obtained. 
ii.  A 4°C temperature increase occurs at all three depths as this has been 
shown as the necessary temperature change to increase tissue 
extensibility. 
iii.  A 45°C temperature is reached at any depth, due to concern of tissue 
damage at high temperatures.  
iv. The subject experiences any pain or discomfort during the treatment.  
11. Following the treatment, the ultrasound gel will be wiped from the leg, the template 
and thermocouples will be removed, and the insertion sites will be cleaned with 70% 
isopropyl alcohol wipes and covered with a band aid. 
12.  The subject will then be instructed on the possibility of minor soreness for the next 
day or two and instructed on an icing schedule to decrease discomfort.