Authors reply to comments on "Line patterns in the mosaic electric properties of human skin-a cross correlation study"

We read with interest the comments of Lin et al. [ibid., vol. 49, p. 274, 2002] on our paper "Line patterns in the mosaic electric properties of human skin-A cross correlation study" [ibid., vol. 48, p. 731-4, 2001]. The authors point out that our measurements will only reveal meridian lines expressed in the epidermis. This is indeed true and the instrumentation was intentionally designed to focus on the epidermis since, to our knowledge, most publications regarding the electrical properties of acupuncture points or meridian lines deal with low-frequency or direct current and, hence, only the epidermis (dominated by the dead stratum corneum). The authors furthermore suggest identifying meridian lines indirectly by locating low-resistance points in the epidermis. The ohmic resistance of the epidermis is totally dominated by the dead stratum comeum and will greatly change locally where active sweat ducts form electrical shunt paths through the stratum corneum. Since the density of sweat orifices on most nonpalmar or nonplantar skin sites is roughly 100 pr /spl middot/ cm/sup 2/, these sweat ducts will be the most obvious reason for any low-resistance points found on skin, at least until otherwise is shown. Consequently, any detection method for acupuncture points will be inadequate if based on, or even influenced by, the direct current resistance (or conductance) of the skin, since it will also detect the large number of densely dispersed sweat ducts in the skin. This is the reason why also electrical susceptance was measured in our study, since this parameter is not influenced by the sweat ducts.

[1]  William Montagna,et al.  The Structure and Function of Skin , 1956, The Yale Journal of Biology and Medicine.

[2]  P. Caminal,et al.  Alignment methods for averaging of high-resolution cardiac signals: a comparative study of performance , 1991, IEEE Transactions on Biomedical Engineering.

[3]  M. S. Mobin,et al.  Weighted averaging of evoked potentials , 1992, IEEE Transactions on Biomedical Engineering.

[4]  D. Holmes,et al.  Echocardiographic identification of commissural calcium: A simple but effective predictor of outcome after percutaneous mitral balloon valvuloplasty , 1996 .

[5]  Sverre Grimnes,et al.  Bioimpedance and Bioelectricity Basics , 2000 .

[6]  Low Frequency Dielectric Dispersion of Microporous Membranes in Electrolyte Solution , 1998 .

[7]  Sverre Grimnes,et al.  Measuring depth depends on frequency in electrical skin impedance measurements , 1999 .

[8]  Sverre Grimnes,et al.  Line patterns in the mosaic electrical properties of human skin-a cross-correlation study , 2001, IEEE Transactions on Biomedical Engineering.

[9]  P. Lander,et al.  Time-frequency plane Wiener filtering of the high-resolution ECG: development and application , 1997, IEEE Transactions on Biomedical Engineering.

[10]  J C Zhong,et al.  On two weighted signal averaging methods and their application to the surface detection of cardiac micropotentials. , 1991, Computers and biomedical research, an international journal.

[11]  L Sörnmo,et al.  Detection of cardiac late potentials in nonstationary noise. , 1997, Medical engineering & physics.

[12]  Michael E. Cain,et al.  Signal-averaged electrocardiography , 1996 .

[13]  V Hombach,et al.  Standards for analysis of ventricular late potentials using high-resolution or signal-averaged electrocardiography: a statement by a task force committee of the European Society of Cardiology, the American Heart Association, and the American College of Cardiology. , 1991, Journal of the American College of Cardiology.

[14]  P. Lander,et al.  Time-frequency plane Wiener filtering of the high-resolution ECG: background and time-frequency representations , 1997, IEEE Transactions on Biomedical Engineering.