Rife Frequencies, The Skin Effect and
Bio-electrical Impedance Analysis. Including
the Necessity of using an RF Carrier Frequency

There are some who sell so-called "Rife Machines" that use single ray tubes and two hand-held ray tubes. They claim that the frequencies which Dr. Rife used on microorganisms will not penetrate into human skin and internal body tissue when using metal hand-cylinder electrodes. They claim only their single ray tube or hand-held ray tubes have this capability. This belief is based on their incorrect understanding of what the "Skin Effect" really is and how it works. They are applying the "Skin Effect" definition of a metal wire to human skin and tissue as though they are made of the same material. Here is one of their quotes:

"Much research has been done proving that the higher the frequency, the more the current follows the outside of the body. Thus it is referred to as the skin effect. The higher the frequency, the shallower the penetration. At frequencies above 1 MHz, skin effect will limit penetration to a fraction of
an inch."

Actually this claim is false and misleading. There has been no research done that verifies this claim for any of the frequencies in the range that Dr. Rife used and his frequency range went from 15,779 Hertz to about 18 million Hertz or cycles per second. The research on high frequencies they are talking about deals with frequencies thousands of millions of Hertz higher than want Dr. Rife used.

In a 1997 Harvard Education Course about "Absorption of RF Radiation" (Not dangerous X-ray radiation), the following is stated under the title of "How do different tissues absorb radiation?" We quote:

"At frequencies between 300 and 3000 MHz [300 million Hertz to 3000 million Hertz], electromagnetic energy can penetrate into more deeply situated tissues, making it especially desirable for therapeutic applications."
http://people.seas.harvard.edu/~jones/cscie129/pages/health/
absorp.htm#frequency

Since the frequency range that Dr. Rife used did not even exceed 20 MHz (20 million Hertz) and this frequency range can and does "penetrate into more deeply situated tissues." This means their statement that "At frequencies above 1 MHz [1 million Hertz], skin effect will limit penetration to a fraction of an inch" is incorrect. It is actually frequencies which are below 1 MHz (1 million Hertz) that have difficulties penetrating human cells and this is the main reason why Dr. Rife used an RF Carrier frequency of 1 MHz or higher with these low audio frequencies. The importance of why Dr. Rife used an RF Carrier frequency will become apparent as we continue to discuss the topics of the "Skin Effect", “Body Impedance Analysis” and an "RF Carrier" frequency. Every quote we give will be backed up with links to the supporting documents.

Having now corrected this 1 MHz "penetration to a fraction of an inch" incorrect information we will continue by reading the "Skin Effect" definition which will correct additional incorrect statements that have been made. Quote:

“Skin effect is the tendency of an alternating electric current (AC), electrons to flow more at the outer surface of the wire rather than through the middle. The higher the frequency, the more the skin effect and the greater the resistance. Stranded wire produces less skin effect than solid wire, because there is more surface area. The skin effect enables copper-clad steel wire to be used. The steel adds cable strength, and the current flows mostly through the better conducting copper. The skin effect is due to opposing eddy currents induced by the changing magnetic field resulting from the alternating current. At 60 Hertz in copper, the skin depth is about 8.5 mm. At high frequencies the skin depth becomes much smaller. Increased AC resistance due to the skin effect can be mitigated by using specially woven litz wire.” https://en.wikipedia.org/wiki/Skin_effect

If you read carefully the "Skin Effect" definition above, you notice that the "Skin Effect" only pertains to a metal conductor or electrical wire. There is no mention of human skin or tissue in its definition because it has nothing to do with it. In fact, the "Skin Effect" does not pertain to human tissue, skin or any of the frequency ranges used by Dr. Rife with all of his "Rife Machines" built from the 1920s to the 1950s.

There are many videos and written scientific reports on the web about how frequencies can and do penetrate body tissue. If you just do a search of "Body Impedance Analysis" you will find dozens of these reports and the equipment used for taking these measurements. These reports deal with body composition such as body fat, lean muscle mass, bone, and water which is measured by sending various frequencies into the body tissue, with stick-on electrodes, which work no different than metal hand-cylinder electrodes. The most important part about this scientific "Body Impedance Analysis" information is that it scientifically shows how frequencies can and do penetrate human skin and body tissue. Also you will find below on this page a complete scientific "Body Impedance Analysis" report and links to several of these reports. There is also a link to an "Absorption of RF (Radio Frequency) Radiation Report" for those who want to read more about this subject since Dr. Rife used audio and RF frequencies in his Rife instruments.

Some people find these body impedance reports difficult to understand so we
have included links for 2 videos which talk about "Body Impedance Analysis" and show how frequencies penetrate human skin and tissue. You will want to watch these 2 short easy to understand videos. The first video is only about 3 minutes. The second video is only about 5 minutes and it talks about some of the same information which is in the first video, but it also mentions at 3 minutes and 50 seconds a 534-ohm body resistance reading measured with the "Body Impedance Analysis" instrument used in the test. This 534-ohm body resistance reading will be important to this discussion of how electrical frequencies penetrate human skin and other body tissues.

#1 https://www.youtube.com/watch?v=047lML9ndPo

#2 https://www.youtube.com/watch?v=vTcUS3qCLSU

There is more information that should be understood before reading the "Body Impedance Analysis" report below. In this discussion, we do not want to get lost in how these "Body Impedance Analysis" instruments are able to read lean muscle mass, body fat, and water. What we are interested in is how frequencies penetrate the skin, body fat, cells and muscle mass using electrodes. If there really was a "Skin Effect" with human tissue then the many available body impedance instruments sold on the market today would not be able to read anything because the frequencies they use would not be able to penetrate the skin or body tissue. All of the scientific evidence proves there is no such thing as the "Skin Effect" with human tissue.

There is another type of report on this subject that can give us information about how frequencies interact with human skin and tissue. They are 'Deaths By Electrocution.' We will be quoting from these type of reports.

The U.S. Department Of Health And Human Services published a summary of The National Institute for Occupational Safety and Health (NIOSH) report entitled "Workers Deaths By Electrocution." On pages numbered 6, 7 and 8 of that 51-page report, they talk about how common house wall socket electricity of 110 volts at 60 Hertz (60 cycles per second) can enter the body causing both injury and death if the current or amperage is too high. In the last two paragraphs on page 7, they state the following about the bodies resistance levels. Quote:

"Under dry conditions, the resistance offered by the human body may be as high as 100,000 Ohms. Wet or broken skin may drop the body’s resistance to 1,000 Ohms...Ohm’s law demonstrates how moisture affects low-voltage electrocutions...High-voltage electrical energy quickly breaks down human skin, reducing the human body’s resistance to 500 Ohms. Once the skin is punctured, the lowered resistance results in massive current flow...Again, Ohm’s law is used to demonstrate the action." https://www.cdc.gov/niosh/docs/
98-131/pdfs/98-131.pdf

Now with this understanding, we will discuss the 534-ohm body resistance reading mentioned in the above second video. Because the human body skin and tissue resistance varies from person to person there have been many scientific tests done to determine what the overall body average resistance is. In one such scientific report intitled "Conduction of Electrical Current to and Through the Human Body: A Review" it states on pages 408, 417 and 418 the following. Quote:

"Unless otherwise noted, this article is referring to currents and voltages of 60 (or 50) Hz AC [alternating current] rms. Also, by resistance, we actually mean the magnitude of the impedance...The total body resistance from hand to foot in water is considered to be 300 ohms when considering safety precautions. Smoot measured a total body resistance of 400 ohms with immersion. Much of this is due to the internal body resistance. Thus, immersion eliminates most of the skin resistance...The total body resistance in water is of 300 ohms. Thus, the current needed and the resistance it must experience are known."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2763825/pdf/
eplasty09e44.pdf

Below are two diagrams. The first one is of the average internal human body resistance or impedance without the external skin impedence measurements. This diagram (in its black and white version) can be found in the document entitled "Comparison of touch and step voltages between IEEE Std 80 and IEC 479-1" at the link below. It is a read online document. There are many other body impedance diagrams similar to this one on the internet, but this one we believe has the most accurate measurements. Other diagrams will give readings of about 500 ohms from the hand to the foot which is the average measurement, but they do not explain that their reading includes internal body impedance and the two skin impedance readings which must be included. This diagram gives all of the readings including measurements if you use two hands and one foot. Doing this gives more skin surface area for the electrodes which would lower the overall impedance for the frequency being used. The second diagram below shows how the body impedence lowers as the frequency goes higher.

https://dokumen.tips/documents/iec-479-1.html

In the above second video, the hand-to-foot 534-ohm body resistance reading was done with stick-on electrodes. They are not as conductive as immersing the skin into water. If you look at the above diagram with its measurements you can see the resistance for hand-to-foot is 100 ohms. This must be added to the two skin contact points of 50 to 100 ohms each. If we use the 100 ohms measurement this would equal 300 ohms matching the statement "The total body resistance in water is of 300 ohms." The person in video #2 had a hand-to-foot 534-ohm body resistance reading. The average person measurement was listed as "400 ohms." These measurements give us an average ohms range from 400 ohms to about 550 ohms for testing the power output capability of any instrument. This ohms measurement is necessary when doing any type of “Load Test” when using an "ohms law calculator" to determine the power output in watts of an instrument.

In all "Bio-Impedance Analysis" reports, like the one which was quoted above, we find that water "immersion eliminates most of the skin resistance." This covers all of the frequencies in the low audio frequency range. It also has the same effect with higher frequencies which are in the higher RF (Radio Frequency) ranges that Dr. Rife used. The reason for this is that the higher the frequencies go up into the RF range the body impedence or resistance lessens and the frequencies penetrate easier into the tissue. An easy way to understand this is that a radio station broadcasts on its RF frequency band and its signal is able to penetrate through our walls and we can listen to that station. The wall cannot stop the radio station frequencies. The combination of the wet skin and higher frequencies completely eliminates any cell and tissue resistance if an RF Carrier frequency of at least 1 Megahertz (1 million Hertz) is used with lower frequencies.

Because of what has been explained it is important when using any type of metal electrodes, such as metal hand-cylinders and footplates, to use some form of cloth covers which can be immersed in water. They should be as wet as possible without water dripping from them. This will make the surface of the skin, which will be touching the wet cloth covers, as wet as being immersed in the water allowing the maximum power transfer of the frequencies into the user.

Below is a Body Impedance Analysis diagram showing how the different frequency ranges penetrate the cells and tissues of the body. In the National Institutes of Health Technology Assessment Conference Statement of December 12-14,1994 intitled "Bioelectrical Impedance Analysis in Body Composition Measurement" it states on page 15, last paragraph the following:

"It is commonly assumed that a 50-kHz (50,000 Hertz) signal penetrates cell membranes and freely passes through all fluids. Unfortunately, this assuption is known to be false; the current is carried by extracellular fluid plus some component of intracellular fluid."
https://consensus.nih.gov/1994/1994bioelectricimpedancebodyta
015pdf.pdf

Importance Of Using An RF Carrier Frequency Like Dr. Rife Used

There are several so-called "Rife Machine" manufactures that claim that any use of an RF Carrier frequency, like what Dr. Rife used, is potentially harmful. Below are a few of the many statements that have been made. Quote:

"We don’t wast power in creating and transmitting detrimental carrier frequencies.”

"We don’t use any wasteful and potentially harmful fixed carrier frequency.”

“We do not use a carrier wave as promoted by some manufacturers.”

“Other researchers have drawn similar conclusions as regards to carrier waves being unnecessary as long as the device has sufficient output.”

In these statements, they justify not using a carrier frequency, like Dr. Rife used because other so-called researchers including themselves believe the RF Carrier frequency is "detrimental, wasteful, potentially harmful and unnecessary." They have come to believe they are smarter or more intelligent than Dr. Rife.

We will now show that all of these statements are incorrect and that an RF Carrier frequency is absolutly necessary in order to get low frequencies into the cells of the body. The above cell penetration "Bio Impedance" diagram shows clearly why an RF Carrier is necessary. Here is a statement of Dr. Rife's which shows that he used an RF Carrier frequency. Quote:

"The basic principle of this device is the control of a desired frequency. These frequencies varying upon the organisms being treated. The frequency is set which controls the initial oscillator, which in turn is run thru six stages of amplification, the last stage driving a 50-watt output tube.

The frequency with its carrier wave is transmitted into an output tube [gas filled plasma ray tube] similar to the standard X-ray tube but filled with a different inert gas. This tube acts as a directional antenna. The importance in the variable control of these frequencies is that each pathogenic organism being treated is of a different chemical consistency, the consequence being they carry a different molecular vibratory rate. Each one in turn under these conditions requires a different frequency or vibratory rate to destroy." (Letter from Jack Free to Dr. Milbank Johnson M.D., December 17, 1935) http://www.rifevideos.com/pdf/pdf_files_for_rifevideos/
12_17_1935_rife_ray_discription.pdf

Dr. Rife used audio and RF frequencies in his instruments. He also used an RF Carrier frequency with all of his instruments. In all of the "Body Impedance" testing, we find that there is no cell penetration with any audio frequencies below 10,000 Hertz. We also read it is:

"commonly assumed that a 50-kHz (50,000 Hertz) signal penetrates cell membranes and freely passes through all fluids. Unfortunately, this assumption is known to be false."

Cell membrane penetration begins to have some penetration at about 10,000 Hertz and slowly goes deeper into the cell, but, it does not achieve full cell penetration until 1 Megahertz (1 million Hertz). This is the reason why an RF Carrier frequency, like the one Dr. Rife used, is absolutely necessary especially with frequencies below 100,000 Hertz. Over 98% of all the frequencies that are used with almost all of the so-called "Rife Machines" are below 40,000 Hertz.

What really limits using audio frequencies without the use of an RF Carrier frequency is the voltage and current levels must be limited for the safety of the user. Most people can only handle about 1/10th (0.10) to 2/10ths (0.20) (Average person about 0.12) of 1 watt without the use of an RF Carrier frequency. Once an RF Carrier frequency is used the frequencies cannot be felt by the user so the power level can be increased to as much as 15 to about 20 watts without the body feeling anything as long as a large enough skin surface area is used. Dr. Rife never used high power levels in direct contact with the skin of a person that could cause injury. This also does not mean that very low power levels will produce results either. There is a balance of power that is needed which will not harm a person but will accomplish the desired results and only an RF Carrier frequency makes this power level possible.

Life Labs 1957 Contact Pad Instrument

In 1957 Dr. Rife's two business partners, John Crane, and John Marsh came up with the concept of using low power contact instruments. Above is a photo of the first 1957 contact instrument and the title above it is a link to a page with a great deal more documented information about this 1957 instrument.

"Tens Machines" that do not use an RF Carrier frequency, are used by many physical therapists and chiropractors. These instruments output frequencies in the low audio frequency range of 1 Hertz to about 50,000 Hertz. These frequencies are used to stimulate muscles and tendons which help to heal by reducing inflammation and other problems with their patient's body.

These Tens Machines use highly conductive electrode pads that come in contact with the skin of the user to deliver the frequencies. John Crane and John Marsh decided in 1957 to use this electrode contact method with a frequency generator to deliver the frequencies to the user, instead of using a glass plasma filled ray tube. They wanted a less expensive instrument so people could afford one. This is how the contact method of using metal electrodes got started with contact type frequency generators. Notice in the photo above it has two metal round disks. Later metal hand-cylinders replaced these disks. This contact electrode method was and is built upon a solid scientific foundation called "Conduction" that is still used today by many health practitioners.

In the 1970's Bertrand Comparet, Dr. Rife's attorney was interviewed by Dr. Hubbard M.D. They discussed the low power metal contact type instrument and this is what Comparet stated. Quote:

COMPARET: “And I asked Rife, because I thought Rife would certainly say that the way Crane was working on it then was still using the Rife principle, but he indignantly denied it.”

HUBBARD: "All right, I see. But, getting back, you say that Rife was very indignant, that the machine that Crane was building was really his [Cranes] idea. I suppose he did not compromise on that, did he?

COMPARET: "Oh no, he just blew up." (1970’s Bertrand Comparet interview #32 & 40)

Here is another statement Bertrand Comparet made in that interview. Quote:

COMPARET: “Now, Crane said “Well now look, Rife himself admits that no matter how much tube and ray, and so on, you have, you can’t get any results unless you’ve got the right frequency. Therefore the real clue to the thing is the frequency and not the means by which you deliver it.”
(1970’s Bertrand Comparet Interview #33)

Dr. Rife knew a metal antenna, as well as a plasma tube, could be used to broadcast the frequencies. The real mistake John Crane and John Marsh made was not using an RF Carrier frequency of at least 1 MHz (1 million Hertz) or higher. The 1936 Rife Ray #5 or Beam Ray Clinical machine which was built and sold to doctors used an RF Carrier frequency in the 3 to 4 MHz range. As stated before; there is a balance of power that is needed. Also, all of the "Body Impedance" testing shows that low frequencies, less than 1 million Hertz, cannot penetrate the cell where many pathogenic organisms are found. Most of the frequencies used by many people are almost all below 50,000 Hertz. Without an RF Carrier frequency, there is no chance they can ever fully penetrate the human cell. Even if a square wave waveform is used with the frequencies the higher harmonics still do not reach, with sufficient power, 500,000 Hertz. Because of this fact an RF Carrier frequency is still needed to get those frequencies, and their square wave harmonics, into the cells where they are needed.

The various "Body Impedance Analysis" reports and the "Absorption of RF Radiation" report proves beyond a doubt that anyone who claims an RF Carrier frequency is not needed does not understand what they are talking about. Only an instrument that uses an RF Carrier frequency, like Dr. Rife used, can hope to produce the result his instruments did. People should not be misled into believing that an RF Carrier frequency, in the ranges used by Dr. Rife is "detrimental, wasteful, potentially harmful or unnecessary."

Dr. Rife worked with frequencies from the audio range up to about 18 MHz (18 million Hertz). This range of frequencies is very low compared to the 300 million to 3000 million Hertz range. All of the scientific reports we have quoted from show that there is no “Skin Effect” in any of the ranges Dr. Rife used especially below 20 MHz (20 million Hertz). Below is the link to the Harvard report which we recommend that you take the time to read. Below that link is another link to a "Body Impedance Analysis Physicians Overview" report which also confirms the information presented here.

Harvard Report “Absorption of RF Radiation" link

Bioimpedance monitoring for physicians: an overview

All of the reports we have read from confirm that frequencies will pass through human skin into the tissues of the body, using electrodes, as long as the proper methods are used.

There are limits to frequency penetration depending on whether a low frequency (5,000 Hertz) is used or a high frequency (1MHz or 1,000,000 Hertz) is used. The diagram above (fig 4.4) shows this. These limits only apply to cell penetration. These reports show that low frequencies only go through the connective tissue where high frequencies can fully penetrate all of the cells of the body. The real question that should be considered is: What is the Cell Effect? The false concept that human or animal tissue is affected in the same manner as a metal wire only exists in the minds of those who have not read these scientific reports. The full scientific "Body Impedance Analysis" report, given below, with links to other reports is presented to give documented factual information on this subject to the reader about how high frequencies are needed for full cell penetration and the necessity of using an RF Carrier frequency with sufficient power to produce the desired results.

Because most of these types of reports are a little technical we will give a simple explanation at the end of each section, in blue color print, if one is needed. At the end of the report, at the bottom of this page, we will give a complete summary of this report.

The Bio-Electrical Impedance Analysis Report:

Bio-electrical impedancemetry or Bio-electrical lmpedance Analysis (B.I.A.) initiated in France by A.L. THOMASSET in 1962 today forms part of the arsenal of the means of exploration of biological tissues. Already widely diffused in the USA and the Anglo-Saxon countries, this method has a promising future. After a brief historical recapitulation, this work will present the basis on which the method was founded, followed by some examples illustrating its numerous applications in the medical field, as well as the perspectives opened up in biological research in general. In a word, Bio-electrical IMPEDANCEMETRY is a simple technique allowing easy measurement of body water and its extra and intra-cellular distribution in the organism.

Water is the main component of the human body where it represents 58% to 62%, of the body weight. In many pathological cases, this quantity varies. However, until now, because of the absence of simple means, it was not measured. Today, this measurement is at the disposal of all physicians thanks to Bio–Electrical Impedance Analysis: B.I.A.

The first concerned are nephrologists for the monitoring of hemodialysis and nutritionists. But many other physicians are concerned by this work, as for example those in medical and surgical intensive care, those in units for the severely burned, cardiologists and those involved in metabolic disorders. Moving away from such specialties, other physicians and researchers in sports medicine, occupational medicine, thermal medicine, and of course in physiology and biology will find in this work many arguments allowing them to develop their activities.

Historical Background

It was by studying the electrical activity of the brain by EEG that A.L. Thomasset in Lyon from 1955 to 1960 observed that the differences of potential could be similar to the law of Ohm and comply to the formula: U = R. I. This idea led the author to look for the value of R, the electrical resistance of the brain tissue, then step by step to measure that of the whole body. For this, the body being both an ionic and non-homogeneous conductor, it was necessary to use an alternating current (AC) and not a direct current (DC). Because of this, the resistance studied took the name of impedance, a value expressed by the symbol Z. The equality U = R. I is therefore written U = Z. I i.e. Z = U/I, U being the difference of potential, I the intensity of the measurement current. Then, if we use for the measurement a current of constant intensity I the potential in volts that is collected between two electrodes is equivalent to Z multiplied by this constant U = Z. Cte and is representative of the impedance of the conductor. None-the-less, this measurement should be performed in certain precise conditions that we shall examine later.

Now as from the beginning of the study most of these conditions were fulfilled, as the measurements were systematically recorded in the morning, between 8 and 9 am, in a medical department where men and women were hospitalized for various reasons, it allows us to confirm that the measurements were reproducible.

This reproducibility was the fundamental and determining quality without which the study could no longer be pursued. All the authors who had studied the problem before, since d' Arsonval, Cole and Curtis Barnett, to mention only a few, placed without success the un-moistened electrodes on the skin a capricious barrier for the current that needs only to be traversed by using moistened electrodes or needle-electrodes inserted under the skin to avoid this pitfall.

Given this, the meaning of the body impedance measurements was a simple game thanks to the work of the school of F.D. Moore at Harward, while H.P. Schwann in Philadelphia, Ch. Eyraud and J. Lenoir [15] of the C.N.R.S. in Lyon validated the study scientifically.

In defense of physicians, it should be admitted that, until now, they had no simple means at their disposal to perform such a measurement. Today, this means is now available to them through electrical impedance measured by a method that we developed as from 1962 and experimented in various fields of physiology and medical practice.

We trust that the readers will find in this presentation the basic elements of the method as well as some examples of applications liable to throw light on their own observations.

Explanation: Alternating current (AC) is used for biological tissue not direct current (DC). Earlier experimenters were unable to read body impedance because they did not moisten the skin or insert needles. Today many-body impedance devices, which do not use needles, are used to determine if there are any blockages in the electrical flow in the body. Many of these instruments, such as the Bio-Meridian an FDA approved device, use a metal probe to access meridians of the body. The skin must be moistened at each meridian point in order to check the impedance. Defibrillators which are used to electrically shock the heart use a conductive jell in order to prevent burning of the skin, allowing the electrical current to enter the body. Moisture is the key to getting frequencies into the body without the use of needles.

Electrical impedance

The word impedance comes from the Latin impedire meaning to prevent, to stop from going on. In terms of electricity, impedance signifies the resistance of a conductor when an electric current passes.

However, conventionally speaking, the term resistance refers to the obstacle to the direct current, and it is represented by the letter R.

The terms impedance refers to the obstacle to the alternating current and it is represented by the letter Z.

Impedance Z, as resistance R, is expressed in ohms.

Explanation: Resistance refers to the obstacle of (DC) direct current. Impedance refers to the obstacle of (AC) alternating current.

Electrical conductivity

The electric conductivity of a conductor is its capacity to conduct the current. It is called conductance for a direct current (DC) and admittance for an alternating current (AC).

Conductance is equal to the inverse 1/R of the resistance. Admittance is equal to the inverse 1/Z of the impedance.

In both cases, conductivity is expressed in mho (the inverse of the word ohm). In practice, use has prevailed, and most often the designations resistance or impedance expressed in ohms are employed to define conductivity.

Explanation: Skin and body tissue has resistance or impedance to electrical current and voltage which is measured in ohms. Resistors come in various ohms values which limit voltage and current. The overall average body electrical resistance or impedance, when wet, is about 400 to 600 ohms.

Resistivity of a conductor

This is the resistance that a sample of this conductor with a length and section equal to one unit opposes to an electric current passing through it between two electrodes each with a section equal to one unit and placed on two opposite faces of the volume thus defined of the sample to be measured.

1 cm Example: The resistivity of copper is the resistance of a cube of this metal measuring 1 cm on each side, through which passes a current between two electrodes measuring 1 cm2 placed on sides A and B of this cube (fig 3.1).

Resistivity is conventionally expressed by the Greek letter p. It is measured by means of a direct current if we are dealing with an electric conductor such as iron or copper, and by means of an alternating current if it is an ionic conductor and furthermore non-homogeneous such as a biological tissue, but in this case resistivity varies with the frequency of the measurement current, and one should indicate the frequency of the current used in the following manner: p5kHz or p1MHz

Explanation: Resistance depends on the material and frequency used. All human cells and tissue has impedance or resistance to electrical current such as frequencies from 5KHz (5,000 Hertz) to about 1MHz (1 million Hertz). Many tests have shown that the overall average resistance of skin and body tissue may drop as much as 50% with high frequencies of 1MHz or greater. This drop in cell resistance starts at about 10kHz (10,000 Hertz) and gradually decrease as the frequencies go higher to 1MHz. At 1MHz there is no cell resistance and the frequency fully penetrates through the cell.

Notion of the frequency of an electric current

A direct current (DC) has a null frequency. It passes through a conductor always in the same direction from the positive pole to the negative pole.

An alternating current (AC) is an oscillating current usually sinusoidal (a sine wave waveform) which passes through a conductor alternately in one direction then in the opposite direction, a certain number of times per second.

This number of times depends on the generator that produces it. It may vary from a few units (as is the case for the domestic current of 50 Hz (Hertz), or cycles per second, in France), to several million cycles per second. This number is called current frequency and is expressed in cycles per second or in Hertz (Hz).

A current is said to be of low frequency (LF) when this frequency is below 50,000 Hertz, of (MF) medium frequency between 50,000 and 500,000 Hertz, and high frequency (HF) above 500,000 Hertz.

When studying body impedance the current used in (LF) low frequency is 5,000 Hertz or 5 kHz (kilohertz), and in (HF) high frequency 1,000,000 Hertz or 1 MHz (1 Megahertz).

Explanation: Direct current (DC) has a null frequency. This means the energy flow can stop in the body after a short period of time (as little as 3 minutes) because it is only going in one direction from the positive pole to the negative pole. Alternating current (AC) has no null frequency because it alternates back and forth from one pole or electrode to the other pole or electrode.

Why use an alternating current (AC) to measure the impedance of a biological tissue?

Essentially for two reasons:

Because a biological tissue is an ionic conductor: it is known that electrical conduction in a material occurs through charge carriers, which may be electrons, such as is the case for metals; or free ions in suspension in solutions, as is the case for biological tissues.

If a direct current (DC) is passed through an ionized solution, the well-known phenomenon of polarization occurs, i.e. very rapidly at the level of each electrode a double layer of ions is deposited which acts as an insulator and prevents the current from passing. Therefore, a direct current (DC) cannot be used to measure the resistance of such a conductor.

Because it is a heterogeneous conductor: i.e. it is composed of both resistive elements and [noref] capacitive elements diversely associated. Whereas the resistive elements allow the alternating current to pass whatever its frequency, the capacitive elements allow the alternating current (AC) to pass only if it has a high frequency.

Such that the opposition encountered by electricity to circulate in a biological conductor must necessarily be studied by means of an alternating current (AC). Thus it is indeed an impedance.

Explanation: Direct current known as (DC) current travels in only one direction. Direct current cannot be used to measure the resistance of the human body. DC current causes ions to build up eventually causing polarization. This can cause heating in tissue if one is not careful. Alternating current (AC) is safer to use in biological tissue and will allow the passage of high frequencies through the body tissue including the bone.

Capacitive element

This is an element able to store electrostatic charges. A condenser with its two armatures (fig 3.2) separated by an insulator (Di-electric) is a capacitive element.

In biological tissues the cellular content represents one of these armatures; the interstitial fluid represents the other. They are separated by the cell membrane which plays the role of an insulator or di-electric. In common language in electricity to designate a condenser the term capacity is often used, the object being designated following its function. This is an improper use of language; in fact, the capacity Cp represents the ability of a conductor to receive a charge Q.

Explanation: The body can receive an electrical charge such as a frequency.

Capacity and impedance of a condenser

This capacity is evaluated in farads and depends on the form, the dimensions of the di-electric as well as the nature of the di-electric.

A condenser (capacitive element) interrupts the circulation of the direct current, for as soon as its armatures are charged, one positively, the other negatively, the current no longer passes.

On the other hand, an alternating current appears to cross the obstacle represented by the di-electric of the condenser. In reality, the condenser acts on the current by retarding it by a half-period (90% or k/2) (fig 3.3).

The condenser impedance (1/C2kf) is all the higher as the frequency is lower and reciprocally it tends towards zero when the current frequency tends to infinity. It may be considered that the condenser conducts in a normal fashion the alternating current, which is true in practice if not in theory.

These notions concerning the properties of condensers show why a low frequency current does not cross the membranes, whereas they are crossed all the more easily as the current frequency is high. A condenser can accumulate a certain electric charge Q whose value is given by the formula:

Q = Cp x U, where U is the difference of potential between the armatures, Such that: Cp = Q/U.

A difference of potential U represents the difference of concentration of the charge carried between the two poles of a resistance conductor R when this conductor is traversed by a current of intensity I
(Ohm's law U = R x I)

Explanation: The lower the frequency (1 Hertz to 100,000 Hertz) the more difficulty the frequency will have in penetrating into the body. Moisture is critical for the use of low frequencies. High frequencies (1 million Hertz or 1MHz) will penetrate the body with less resistance and will fully penetrate through the cell membrane. Moisture is still critical for the passage of high frequencies and it should be used with electrodes.

Impedance variation of a biological tissue according to the frequency of the measurement current

When one studies the impedance Z of a biological conductor it may be observed that it varies according to the frequency of the measurement current. The higher the frequency the more easily the current passes and consequently, the lower the impedance. If these variations are recorded, we obtain a curve whose general aspect is represented in figure 4.1.

It is the aspect that is taken on by the variations of the impedance modulus of a biological tissue as represented schematically in figure 4.2 where cells can be seen surrounded by their membranes enveloped in the extra-cellular fluid as well as the lines indicating the (LF) low frequency (5,000 Hertz) and (HF) high frequency (1,000,000 Hertz or 1MHz) current.

It may be observed that there is an analogy between figure 4.2a and figure 4.2b which shows an electric circuit involving the association of a series resistance (Rs) with a capacitive element (Cp) and an-other resistance (Rp) in parallel. The impedance curve of this classical circuit is represented in figure 4.3 with respect to the frequency. This circuit is called an electronic filter as, depending on the value of the capacity C, it does not allow the electric currents to pass except above a given frequency.

In fact, in the biological tissue the membranes act as a di-electric or an insulator separating two con-ducting media, the extra-cellular fluid (ECF=Rs) and the intracellular fluid (ICF=Rp) which fulfill the role of armatures of the biological condenser. It may be added that the membranes are not a good insulator, and that the condenser they make up is a leakage condenser.

To circulate between A and B (Fig 4.2) a low frequency current 10 KHz (10,000 Hertz) can only take the path Rs, i.e. must pass between the cells. The difficulty encountered is relatively great and the impedance corresponds to the part a and b of figure 4.3.

Between 10 kHz (10,000 Hertz) and 500 kHz (500,000 Hertz) the current takes more and more the path (C+Rp) of figure 4.2 corresponding to the part b and c of figures 4.1 and 4,.3. i.e. it penetrates more and more easily into the cells (Fig.4,4b).

When the frequency is high enough the capacitive effect Cp (Fig. 4.2b) corresponding to the cellular membranes is cancelled and the current passing between A and B takes the two resistive pathways Rs and Rp (fig. 4.4b) such that at the moment we are dealing with a system to which we may apply the formula of Kirchhoff:

This formula will be used later, when estimating the cellular content.
In practice, we have indeed chosen the frequency 5 kilo-hertz (5,000 Hertz or cycles per second) to represent the low frequencies (LF) and 1MHz (1,000,000 Hertz or cycles per second) to represent the high frequencies (HF)

The frequency 5 KHz (5,000 Hertz) was chosen because it represents the mean between 1 KHz (1,000 Hertz) and 10 KHz (10,000 Hertz), i.e. that at 1 KHz (1,000 Hertz) there still subsists a slight polarization of the electrodes (Fig. 4.1) and that at 10 KHz (10,000 Hertz) the current begins to enter into the cells (Fig. 4,4a).

The frequency 1 MHz (1,000,000 Hertz) was adopted as at this frequency the capacitive effect of the membranes is practically null. Further, it is difficult to control the current beyond this frequency without parasiting the conductors, either the equipment, or the body to be measured, the errors liable to occur being greater than the precision sought for.

Explanation: The higher the frequency the less the resistance. At about 1MHz (1 million cycles per second or Hertz) there is less resistance in the biological tissue of the body. Low frequencies below about 50,000 Hertz mostly travel through the connective tissue of the body. At about 10,000 Hertz frequencies begin to penetrate the outside layers of the cell. This scale gradually goes up so that at about 100,000 Hertz penetration into the cell is very noticeable. From 100,000 Hertz to 1,000,000 Hertz (1MHz or 1 Megahertz or 1 million Hertz) penetration increases into the cell and full penetration is achieved by 1MHz. This understanding of how frequencies work in the body explains why an RF Carrier frequency of at least 1MHz (1 million Hertz) should be used. An RF Carrier frequency of 1,000,000 Hertz will have a full body and cell penetration.

It should be understood that all the tests done for this report were done with a sine wave waveform. A square wave waveform creates higher frequency harmonics that may have some penetration into the cell depending on how high the harmonics go up in the frequency range. Theoretically, a square wave produces infinite harmonics but those harmonics lose power with each additional harmonic produced. Therefore depending on how much power is in the primary frequency (10,000 Hertz as an example) the power drops in each harmonic so that within about 12 harmonics the power loss is so great it is almost un-measurable.

For this reason, a frequency of 10,000 Hertz, without the used of an RF Carrier frequency, is limited to a maximum power level of only about 1/10th (0.10) to 2/10ths (0.20) of 1 watt because the user cannot handle the physical intensity of the frequency. This means the power level will be so low in the square wave harmonics that there will be very little cell wall penetration. If an RF Carrier frequency of 1MHz or higher is used then there will be full cell penetration and the power level can be increased up to about 15 to 20 watts without the frequency being felt by the user. For this reason an RF Carrier frequency should be used for full cell penetration with sufficient power to produce positive results.

Resistivity of a biological tissue

The resistivity of tissues varies according to the frequency of the measurement current.

In LF (low frequency) the cells that are concerned in a tissue volume unit act as insulators, enclosed in a liquid conductor of resistivity Pe. (Fig. 4.5a). A current with a weak LF (low frequency) must necessarily pass between them. The more the cells are packed together the greater the resistance (here the resistivity PLF since we are measuring a unit of tissue volume), and conversely, the fewer the cells in this unit of volume, the more easily the current can pass and in this case PLF is close to Pe: (fig. 4.5b).

It can therefore be understood that PLF of a tissue is a function of Pe and γ the latter factor being a factor of form. It is the form that should be taken on by the electric current to pass through the tissue. (Fig. 4 .5c).

Normally the tissue of each organ has a texture, i.e. a constant factor γ, and if we accept that Pe of the plasma is constant, the mean body resistivity PLF of all tissues taken together is constant in the normal state.

It is the same in all subjects in good health, except, as will be seen later, in lean or obese subjects where non-conductive fatty inclusions are more or less great in relation to the normal state (Fig.4.5d) and influence the tortuosity of the electric field in HF (high frequency) as in LF (low frequency).

In HF (high frequency), the measurement current at 1MHz (1,000,000 Hertz), cancels the capacitive effect of the cellular membranes such that to pass through a unit of tissue volume the current uses both ECF and ICF.

The resistivity is therefore a function of Pe (ECF) and Pi (ICF) according to a proportion that depends on the number of cells in the unit of tissue volume measured (Fig 4.6a).

In the case of extra-cellular edema there are fewer cells in the unit of tissue volume measured, and the influence of Pe predominates over Pi in relation to the normal state (Fig. 4.6b).

More rarely, we may be faced with a cellular edema, in this case the influence of Pi predominates in relation to the normal state. Such a case is often encountered in renal pathology (Fig. 4.6c).

It can be seen from these examples that PHF depends more on Pe and Pi than on the factor γ. However, in the case of leanness or obesity this factor γ plays as much a role as in LF (low frequency), di-minishing or augmenting PHF (Fig. 4.6d).

Explanation: Organ tissues are of different density. The denser the tissue the greater the resistance to low frequencies. The illustrations in this report show that low frequencies go around the cells and high frequencies go through the cells. This is due to the fact that there is no cell wall resistance when using high frequencies. This again shows the benefit of using an RF carrier frequency of at least 1 million Hertz (1,000,000 Hertz) when using low audio frequencies.

Description

The skin was the obstacle to be surmounted before approaching the body composition by impedancemetry. Although directly accessible to the physician the skin is a relatively little known organ. Schematically, it is made up of three parts: the epidermis, the dermis and the hypodermis.

The epidermis consists of several superimposed layers: basal cells of the deep layers, with a nucleus, migrate upwards to form a second rather thick granular layer, well delimited, above which there is a third layer which is the corneum, made up of non-nucleated cells, overlapping each other, fused together in depth and open to the external environment, in the same way as microscopic scales. These three layers are pierced by more or less numerous canals whose role is to evacuate perspiration and hairs whose raisonn d'etre is poorly understood.

The dermis underlying the epidermis is the nourishing part of the skin. It contains the blood capillaries bathed in a network of collagen fibers. This layer lies on the hypodermis.

The hypodermis is composed of fatty lobules between which vessels nourishing the dermis work their way. Its thickness is variable, greater in women than in men. It is the hypodermis that makes up the coating an important part of the Fatty Mass, and it is the double thickness of the hypodermis that is measured by the method of skin folds.

Whereas the anatomical structure of the skin is well known, its physiology still hides uncertainties, but it may be said without contest that the epidermis alone ensure 90% of the functions of the skin. Besides the role of barrier separating the external from the internal environment and serving as a container for the fluids, the epidermis prevents the penetration into the organism of noxious products and bacteria, at the same time ensuring the evaporation of water and contributing to the body heat regulation.

Skin impedance

There is little data available on this subject. It is only known that the skin is an insulator for weak currents of low frequency (5,000 Hertz), and that it can be easily passed through by the same currents but at high frequency (1,000,000 Hertz or 1MHz).

This property is due to the corneal layer of the epidermis, it varies according to the anatomical regions and according to the time of day for the same region. The epidermis acts as a leakage dielectric. With the electrodes placed on its surface on the one hand and the sub-epidermal conducting layers on the other hand it forms two variable condensers, as shown in fig. 4.8 which illustrates that a weak LF (5,000 Hertz) current cannot circulate between A and B, as on this trajectory there are two obstacles 1 and 2 representing the epidermis.

On the other hand, if the same low frequency (5,000 Hertz) current enters by means of moistened electrodes or needles placed under the skin in C and D, it can then follow the pathway E-C, but it cannot take the pathway I-C interrupted by the condenser M created by the cellular membranes. To explore the pathway E-C and I-C, the measurement current should necessarily have a high frequency (1,000,000 Hertz or 1MHz).

Explanation and Summary of this full report: The skin is a good insulator and it is difficult for low frequencies to pass through it without needles or moisture. The skin does have moisture in it. Some people have very moist skin and others have very dry skin. It takes a higher voltage to penetrate dry skin than wet skin. Moisture is the determining factor for penetration through the skin into the body at low frequencies (5,000 Hertz). Once the frequency enters the body the determining factor of penetration into the cell is the frequency range used. This report shows that low frequencies go around the cells, through the connective tissue, while high frequencies penetrate both the cells, connective tissue, and bones. A high RF Carrier frequency of at least 1MHz should always be used with low frequencies.

Bio-electrical Impedancemetry or Bio-electrical impedance Analysis tests have shown that there is no metal "Skin Effect" with human tissue. They also show that a carrier frequency of at least 1 million Hertz (1MHz) is necessary to fully penetrate the cells of the body when using low frequencies. Audio frequencies are generally considered to be below 50,000 Hertz. These frequencies need an RF Carrier frequency in order to penetrate the cell wall.

All of the Bio-electrical Impedancemetry Analysis scientific tests which have been done over the past 50 years prove that the "Skin Effect" of a metal conductor does not apply to human or animal skin. They also show that the frequencies that Dr. Rife found for the various disease organisms can be used with electrodes such as metal hand-cylinders and footplates. These should be used with water for the greatest conductivity. Any cloth covers should very wet, but not dripping wet, and this will almost be like immersing the skin in water.

Here are additional links to "Body Impedance" reports that document and confirm what has been discussed in this article.

https://www.cdc.gov/niosh/docs/98-131/pdfs/98-131.pdf

https://sites.google.com/site/antoniivorra/home/electrical-bioimpedance

https://arxiv.org/ftp/arxiv/papers/1805/1805.05200.pdf

https://pdfs.semanticscholar.org/f3c5/539170aad1881377d9f5e5ed9
6fe38e07566.pdf

https://dokumen.tips/documents/iec-479-1.html

https://www.slideshare.net/esregroup/chien-lee-meliopoulos

file:///C:/Users/Me/Downloads/EJ0003-199901-006028%20(9).pdf

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2763825/pdf/eplasty
09e44.pdf

https://core.ac.uk/download/pdf/10900348.pdf