your smartphone
TRANSCRIPT
your smartphone
M. Hirata1, R. Watanabe2
Matsuyama Shimin Hospital, 1Radiology, 2Surgery Matsuyama Ehime/JP
We have no disclosure and financial support.
Abstract ID 69730 -
1. How to use “Smart Puncture”, which is a free application to make
your gyroscope equipped smartphone into beneficial tool for CT-
guided puncture.
2. The advantages of this application.
To overcome this,
we developed a smartphone application to assist CT-guided puncture.
• In CT-guided puncture, with traditional step-wise approach (non-use of CT fluoroscope),
physician has to define the angle of puncture needle by eye measurement as planned
on the reference images.
• This process depends on the physician’s sense. It can be a cause of inaccurate
puncture with large angle error.
Function of the Application
“Smart Puncture” for iOS and Android.
You can move the rotation center by tapping on
the display. It also can be locked if necessary.
Available for free
After setting puncture angle, the smartphone
displays a guideline.
While holding it at any angle, it automatically
rotates the guideline to maintain appropriate
angle.
movie
movie
Function of the Application
It also detects the tilt of the smart phone, and
change the color of the background.
movie
movie
CT scan with radiopaque marker.
Definition of needle angle and entry site.
Mark the entry site and beam line.
Turn on Airplane mode.
Turn off Auto-Lock
Put the smartphone into
sterilized nylon bag
Input the angle(α) into the smartphone
Hold the smartphone along the beam line.
Adjust the tilt of device to make the background black.
Move center of guideline to suitable position and lock.
Finally, just advance the needle along the guideline
shown on the device.
Measure the
Puncture angle on
CT console.
A piece
of cake!
Smartphone
Sixty-seven years old man with sacral bone tumor.
CT guided bone biopsy was done using this application.
Planed puncture angle was defined as 23°.
Finally, biopsy needle was placed at 22°.
23°
22°
After putting the smartphone into a nylon bag,
you can hold it more easily.
movie
This application also works on tablet.
If assistant holds it nearby the workspace,
the physician can concentrate on needle
operation.
CT scan
3. After puncture, the target was scanned by CT.
Then angle Error was evaluated on a workstation.
In order to evaluate the accuracy of this application,
experimental puncture test was carried out.
1. A puncture target was made from melamine sponge.
2. For simulating the procedure without gantry tilt, punctures was carried out using this
application with angles setting of 30 50 70 degrees in a vertical plane
For simulating the procedure with gantry tilt, punctures were done in the same manner
in tilted plane of 15, 30, 45 degrees.
0° 15°
30°
45°
30°
50°
70°
Set angle 30° 50° 70°
Angle Error (XY) 1° 0° 0°
Set angle 30° 50° 70°
Angle Error (XY) 3° 0° 0°
Angle Error (Z) 1° 1° 1°
Set angle 30° 50° 70°
Angle Error (XY) 1° 2° 1°
Angle Error (Z) 0° 3° 3°
Set angle 30° 50° 70°
Angle Error (XY) 2° 1° 0°
Angle Error (Z) 1° 2° 1°
The maximum angle error was 1° without gantry tilt.
The maximum angle error was 3° with gantry tilt. iPhone6 was used for this puncture test.
Tilt of LCD = 0°
Tilt of LCD = 15°
Tilt of LCD = 30°
Tilt of LCD = 45°
Most of smartphones have vibrating structure gyroscope inside, in order
to recognize the movement of the device itself. This application makes
your smartphone into a handy tool which present appropriate puncture
guideline in real time with high accuracy.
Advantages:
1. High availability of devices.
2. Easy preparation. (Just put the smartphone into sterilized nylon bag.)
3. Easy to complete procedure without assistant.
Type of sensor installed in device is nondisclosure.
Accuracy should be verified for each device in usage.
Accuracy should be verified.