Contributed EIT Data:

Detailed information on measurement protocol

% ************************************
% Electrical Impendance Tomography
% VIASYS invitro data
% University of Ottawa
% Department of Electrical Engineering
% Date:   October 14, 2005
% Author: Camille Gomez-Laberge
% ************************************

This README file is the documentation that accompanies the
data collected in these directories: ph1t1/ ph2t1/ ph3t1/
ph3t2/

% ****************************
% THE EXPERIMENT
% ****************************
Experimenter: Camille Gomez-Laberge
Date Collected: October 4, 2005
Locale: Research laboratory, University of Ottawa
Equipment: EIT Viasys / University of Gottingen
Phantoms: All phantoms used are polyethylene pails 30 cm in height and diameter.
Electrodes: See individual phantom descriptions in each part of the experiment.
Electrolytic solution: 0.9% saline solution
Objects: 2 golf balls (non-conductive) 2 cm radius spheres
suspended in solution with 2.7 kg tension fishing line
(nylon).
Measurement Procedure: Ambient temperature in room is 25
degrees Celsius. Details for each part of the experiment
follow:

PART I:
Directory: ph1t1/
Phantom description: Phantom 1 - Uses brass plated,
steel thumb-tacs as electrodes.  They are arranged in
a 16 electrode plane 13 cm above the phantom bottom.
The ground electrode is placed in the centre of the
bottom. The solution is filled to the 26 cm mark.
With time these electrodes became very corroded. The
coordinate system to define the object positions in the
phantom use the ground electrode as the origin. The x-axis
is aligned with electrode 1 and the y-axis with electrode
5. The z-axis is aligned upwards.

Procedure: There are 5 different measurement setups. Each
setup was measured 5 times. Objects are placed at the
electrode plane level (i.e. we only vary the x and y
coordinates). 

Setup 1: No objects in phantom (just solution)
Data files: vitro200905_ph1t1_001.get - vitro200905_ph1t1_005.get

Setup 2: Object 1 in centre of electrode ring (0,0) cm
Data files: vitro200905_ph1t1_006.get - vitro200905_ph1t1_010.get

Setup 3: Object 1 at (0,7) cm
Data files: vitro200905_ph1t1_011.get - vitro200905_ph1t1_015.get

Setup 4: Object 1 at (0,7) cm and object 2 at (7,0) cm
Data files: vitro200905_ph1t1_016.get - vitro200905_ph1t1_020.get

Setup 5: Object 1 at (0,7) cm and object 2 at (7,0)
cm and phantom is distored into an elliptical shape by
compressing the walls in the y-axis direction until the
short axis measures 25 cm across.
Initially the phantom is circular, during the first 6
seconds it is gradually compressed into the elliptical
shape and held like so for the remainder of the
measurement.
Data files: vitro200905_ph1t1_021.get - vitro200905_ph1t1_025.get
Note: Object positions were measured before distorting the phantom.

Averaged data: The five measurements in each setup (1-4
only) have been read into Matlab and avereaged. The average
data is stored in the avgdata_ph1t1.mat file.

PART II:
Directory: ph2t1/
Phantom description: Phantom 2 - Uses brass plated, steel
thumb-tacs as electrodes.  They are arranged in two 8
electrode planes. The lower is at z = 10 cm level and the
upper at z = 20 cm.  The upper ring is offset by a small
rotation so that the electrodes between both planes form
a zig-zag pattern (e.g. Charlie Brown's sweater). The
ground electrode is placed in the centre of the bottom
(0,0,0). The solution is filled to the 30 cm mark.
With time these electrodes became very corroded. The
coordinate system to define the object positions in the
phantom use the ground electrode as the origin. The x-axis
is aligned with electrode 1 (upper plane) and the y-axis
with electrode 5 (upper). The upper plane has all odd
numbered electrodes. The z-axis is aligned upwards.

Procedure: There are 6 different measurement setups. Each
setup was measured 5 times. Objects are placed using
(x,y,z) coordinates.

Setup 1: No objects in phantom (just solution)
Data files: vitro200905_ph2t1_002.get - vitro200905_ph2t1_006.get
Note: Measurement 001.get was discarded.

Setup 2: Object 1 in centre of electrode ring (0,0,15) cm
Data files: vitro200905_ph2t1_007.get - vitro200905_ph2t1_011.get

Setup 3: Object 1 at (0,7,10) cm; object 2 (0,7,20) cm
Data files: vitro200905_ph1t1_012.get - vitro200905_ph1t1_016.get

Setup 4: Object 1 at (7,0,10) cm and object 2 at (0,7,10) cm
Data files: vitro200905_ph2t1_017.get - vitro200905_ph2t1_021.get

Setup 5: Object 1 at (7,0,10) cm and object 2 at (0,7,20) cm
Data files: vitro200905_ph2t1_022.get - vitro200905_ph2t1_026.get

Setup 6: Object 1 at (7,0,10) cm and object 2 at (0,7,20)
cm and phantom is distored into an elliptical shape by
compression. See PART I setup 5.
Data files: vitro200905_ph2t1_027.get - vitro200905_ph2t1_031.get
Note: Object positions were measured before distorting the phantom.

Averaged data: The five measurements in each setup (1-5
only) have been read into Matlab and avereaged. The average
data is stored in the avgdata_p2t1.mat file.

PART III:
Directory: ph3t1/
Phantom description: Phantom 3 - Uses stainless-steel
screws as electrodes.  They are arranged in two 16
electrode planes. The lower is at z = 10 cm level and the
upper at z = 20 cm.  The electrodes between rings are
aligned vertically.  The ground electrode is placed in
the centre of the bottom (0,0,0). The solution is filled
to the 30 cm mark. The coordinate system to define the
object positions in the phantom use the ground electrode as
the origin. The x-axis is aligned with electrode 1 (upper
plane) and the y-axis with electrode 5 (upper). The upper
plane has electrodes 1-16 and lower 17-32. The z-axis is
aligned upwards.
Procedure: Only 16 electrodes were used (the entire bottom ring).
There is only one measurement here as it was used as a
proof of concept test.  The single object is moved around
in a circular motion during the entire measurement.
Data file: vitro200905_ph3t1_001.get
Note: Electrodes were found to have varying impedances between 200 and 400 Ohms according to the system's calibration test. These values are all within the system's acceptable limits.

PART IV:
Directory: ph3t2/
Phantom description: Phantom 3 - see PART III.
Procedure: Only 16 electrodes were used (the entire bottom ring).
The first 5 setups are almost as in PART I. A sixth setup is also added.
Setup 1: No objects in phantom (just solution)
Data files: vitro200905_ph3t2_001.get - vitro200905_ph3t2_005.get

Setup 2: Object 1 in centre of electrode ring (0,0) cm
Data files: vitro200905_ph3t2_006.get - vitro200905_ph3t2_010.get

Setup 3: Object 1 at (0,7) cm
Data files: vitro200905_ph3t2_011.get - vitro200905_ph3t2_015.get

Setup 4: Object 1 at (0,7) cm and object 2 at (-7,0) cm
Data files: vitro200905_ph3t2_016.get - vitro200905_ph3t2_020.get

Setup 5: Object 1 at (0,7) cm and object 2 at (7,0)
cm and phantom is distored into an elliptical shape by
compression. See PART I setup 5.
Data files: vitro200905_ph1t1_021.get - vitro200905_ph1t1_025.get
Note: Object positions were measured before distorting the phantom.

Setup 6: Object 1 at (0,7) cm and object 2 at (-7,0)
cm and phantom is distored into an elliptical shape by
compressing the walls in the y-axis direction until the
short axis measures 25 cm across.
Initially the phantom is circular, during the first 6
seconds it is gradually compressed into the elliptical
shape. Then for the next 6 seconds it is slowly restored
to original shape. This is repeated to simulate periodic
motion (as in chest wall expansion during breathing)
until measurement is complete (60 seconds).
Data files: vitro200905_ph3t2_026.get
Note: Object positions were measured before distorting the phantom.

Averaged data: The five measurements in each setup (1-4
only) have been read into Matlab and avereaged. The average
data is stored in the avgdata_p3t2.mat file. 
% END OF EXPERIMENT