The implementation combines a variety of graphical techniques to create a very powerful system and provide useful graphical results. The software uses a finite elements 3D model of the hand to visualize the measured currents along the characteristic points (Figure 6). Thanks
to this model the points can be precisely identified on the surface of the skin together with the amplitudes of the measured currents. Figure 6 shows the Top and Perspective visualization of the 3D-model and of the currents emitted by selected points. The tool was used to test many characteristic points on different subjects and in particular to analyze points located at the hand. All the measurements were performed by holding the probe in an upright position, at an angle of 80 degrees to the skin, with the tip in contact with the characteristic point being tested. All the conducted measurements showed that the pressure compensation system allows the operator to work on the measurement point with a well defined and repetitive pressure obtaining reliable and repeatable measures that are virtually insensitive to fluctuations in pressure over a wide range of values. The pressure compensation system parameters can be checked and modified by the user through the Graphical User Interface. A computational unit calculates the standard deviation of the data coming from the acquisition circuit in a given number of samples. When the standard deviation is lower than a preset threshold, the current value is accepted and displayed in the results mask.
Figure 6: 3D visualization of the model of the hand and of the currents emitted by selected points.
To analyse the replicability of the measurements, the consistency of the currents emitted by different characteristic points over a time period of 10 minutes was studied. Table I shows the results of the measured currents emitted by point A, 10 times, with an interval of
60 seconds. Point A is point LU10 (Yu Ji or Fish Border) of the Lung Channel (see Figure 7) and it is located in the depression behind the thenar eminence of the thumb, about the midpoint of the palmar side of the thumb, on the junction of the red and white skin.
Table I: Results of the measured currents emitted by point A 10, with an interval of 60 sec.
Figure 7: Various points along the Lung Channel.
All the indicated currents are in nA and the table also provides the standard deviation (SD) and the mean value (MV). Figure 8 illustrates the standardized values of the current (in p.u.) showing that no significant change in current amplitude was found during the time period of 10
minutes. Other detectable currents were measured repeatedly at various point of the hand in different subjects at 60 sec intervals.
Figure 8: Standardized values of the currents emitted by point A every 60 seconds.
One of the innovative features of the tool is the possibility to create and visualize a 3D map of the characteristic points and of the related emitted currents. In fact it can be very useful to have a graphic representation of the value of the currents emitted by a characteristic point and by points located in the nearby surroundings. To perform these measurements the circular surface illustrated in Figure 9 was set. This area is a 1cm radius circle and the centre of the circle represents the position of the point on the skin. The probe was first used to measure the current emitted by the characteristic point and then, moving the electrode around the circumference, to measure the currents emitted by points located at different angles. Detectable currents were measured repeatedly at a specific point of the hand in four different subjects. For example, Figure 10 shows the results of the current emitted by point LU-10 and by nearby points in the first subject. The figure shows the values of the currents emitted by the points in nA and the current % variation with regard to the value of the current emitted by the LU-
Figure 9: Map set to measure the currents emitted by points located in a 1cm radius circular area around the characteristic point.
Figure 10: Values of the emitted currents and % variation.
Figure 11 shows the 3D graphical results of all the measured currents around point LU-10 and Figure 12 shows the current % variation with respect to the value measured in the characteristic point. Figures 13 to 15 show the results of the currents emitted by point LU-10 and nearby surrounding points on the other 3 subjects. All 3D-graphics show the behaviour of the emitted currents in the 4 subjects indicating that the acupuncture points have higher emitted current than the nearby surrounding points. The results of the measurements can be displayed in a realistic way using the developed finite elements 3D model of the hand as illustrated in Figures 16-17. As can
be seen in the figures, the model allows to exactly locate on the skin of the subject the points to be analyzed.
Figure 11: Visualization of the currents emitted by point LU-10 and nearby surrounding points in subject 1.
Figure 12: Current % variation with respect to measured in the characteristic point
Figure 13: Visualization of the currents emitted by point LU-10 and nearby surrounding points in subject 2.
Figure 14: Visualization of the currents emitted by point LU-10 and nearby surrounding points in subject 3.
Figure 15: Visualization of the currents emitted by point LU-10 and nearby surrounding points in subject 4.
Figure 16: 3D model visualization of the currents emitted by characteristic points LU-10 and LU-6.
Figure 17: Visualization of the currents emitted by the characteristic point LU-11 of the hand.
Figure 18 shows the comparison of the measurements conducted on three characteristic points (LU-11, LU-10 and LU-6) along the Lung Channel of a male subject.
Figure 18: Visualization of the currents emitted by characteristic points of the lung channel LU-6, LU-10 and LU-11.