Slew Rate
The blue-collar magnetic magic of these machines rests heavily on a crucial parameter known as the 'slew rate.' In PEMF therapy, the slew rate determines how quickly the magnetic field reaches its peak. This rate can significantly influence the effectiveness of the treatment.
Slew rate is a critical specification in the performance of a PEMF therapy machine. It measures the speed at which the magnetic field intensity changes, reflecting the device's ability to switch from one level to another swiftly. A higher slew rate indicates a faster response time in magnetic field adjustment, which can be essential in targeting specific tissues or conditions.
Slew rate, or the speed at which the magnetic field intensity changes, is believed to influence the efficacy of pulsed electromagnetic field (PEMF) therapy. High slew rates in devices such as the Magnetic Magic PEMF machine can induce a more rapid response in cells, potentially enhancing therapeutic outcomes.
Increased cell permeability may occur, allowing for improved nutrient uptake and waste removal.
Stimulation of the electrical properties of cells may enhance tissue repair and regeneration.
Faster slew rates could lead to more significant pain relief by disrupting pain transmission at a quicker rate.
Understanding the biological effects of slew rate is crucial for optimizing the performance of a PEMF therapy machine and maximizing its health benefits.
When we have PEMF energy available and we induce it too slow into the body, the changes on cellular level are only minimal. The best example is MRI (Magnetic Resonance Imaging) machines in hospitals, used to make computer generated images of organs inside the body, where speed of induction is critical to obtain clear pictures.
Inside these machines are electromagnetic coils - similar to coils of PEMF systems - and these coils are pulsed with very high speed to obtain a very fast speed of induction or 'slew rate'. The high speed is directly responsible for the quality of the obtained computer generated images.
As general rule: the faster the 'slew rate' => the better the image quality will be.
When you ask people - who had an MRI exam - how it was, they will tell you that a constant very loud rhythmic noise was heard during the examination. This noise occurs when large electrical currents are pulsed very fast into the coils inside the machine, causing mechanical movements in the same rhythm as the electromagnetic pulses => resulting in loud noise.
The blue-collar magnetic magic of these machines rests heavily on a crucial parameter known as the 'slew rate.' In PEMF therapy, the slew rate determines how quickly the magnetic field reaches its peak. This rate can significantly influence the effectiveness of the treatment.
Slew rate is a critical specification in the performance of a PEMF therapy machine. It measures the speed at which the magnetic field intensity changes, reflecting the device's ability to switch from one level to another swiftly. A higher slew rate indicates a faster response time in magnetic field adjustment, which can be essential in targeting specific tissues or conditions.
Slew rate, or the speed at which the magnetic field intensity changes, is believed to influence the efficacy of pulsed electromagnetic field (PEMF) therapy. High slew rates in devices such as the Magnetic Magic PEMF machine can induce a more rapid response in cells, potentially enhancing therapeutic outcomes.
Increased cell permeability may occur, allowing for improved nutrient uptake and waste removal.
Stimulation of the electrical properties of cells may enhance tissue repair and regeneration.
Faster slew rates could lead to more significant pain relief by disrupting pain transmission at a quicker rate.
Understanding the biological effects of slew rate is crucial for optimizing the performance of a PEMF therapy machine and maximizing its health benefits.
When we have PEMF energy available and we induce it too slow into the body, the changes on cellular level are only minimal. The best example is MRI (Magnetic Resonance Imaging) machines in hospitals, used to make computer generated images of organs inside the body, where speed of induction is critical to obtain clear pictures.
Inside these machines are electromagnetic coils - similar to coils of PEMF systems - and these coils are pulsed with very high speed to obtain a very fast speed of induction or 'slew rate'. The high speed is directly responsible for the quality of the obtained computer generated images.
As general rule: the faster the 'slew rate' => the better the image quality will be.
When you ask people - who had an MRI exam - how it was, they will tell you that a constant very loud rhythmic noise was heard during the examination. This noise occurs when large electrical currents are pulsed very fast into the coils inside the machine, causing mechanical movements in the same rhythm as the electromagnetic pulses => resulting in loud noise.
Mechanism of Slew Rate - Faraday Induction or Inductive Coupling
There had also been some good scientific evidence in support of the Faraday Induction mechanism of PEMF (the theory that emphasizes dB/dt and trapezoidal waveforms) since 1968, but it had been lost in the noise surrounding PEMF technologies. Since then the electro-magnetic induction-based theory of PEMF was very strongly supported by research like the NASA-JSC and DARPA in the mid 1990’s and early 2000’s by Goodwin and Dennis.
PEMF technology based on Slew rate does not require the assumption that magnetic fields themselves interact directly with living tissues by means of some form of magic, or a complex and poorly-understood quantum physical effect.
Through the well- understood physical mechanism of electro-magnetic induction, wherein the external pulse generator uses non-invasive electric coils to create time-varying magnetic pulses that penetrate living tissue essentially without any strong direct interactions because the living tissue is essentially “transparent” to the magnetic fields themselves. These pulses are inductively coupled across space to the structures within living tissues that have conductive paths, for example around the cell membrane in the paracellular space, or around organelles within cells. These conductive paths within the tissue act as the “secondary” coil of what can essentially be viewed as an air-core electrical transformer, the primary coil being the external PEMF coil.
Based on the well-understood Law of Induction, one of the four classical Maxwell Equations, electrical currents are induced in and around the cells within the living tissue within the conductive paths in and around cells. This takes the form of ions in solution being forced to move, driven by the induced fields [1] .
There had also been some good scientific evidence in support of the Faraday Induction mechanism of PEMF (the theory that emphasizes dB/dt and trapezoidal waveforms) since 1968, but it had been lost in the noise surrounding PEMF technologies. Since then the electro-magnetic induction-based theory of PEMF was very strongly supported by research like the NASA-JSC and DARPA in the mid 1990’s and early 2000’s by Goodwin and Dennis.
PEMF technology based on Slew rate does not require the assumption that magnetic fields themselves interact directly with living tissues by means of some form of magic, or a complex and poorly-understood quantum physical effect.
Through the well- understood physical mechanism of electro-magnetic induction, wherein the external pulse generator uses non-invasive electric coils to create time-varying magnetic pulses that penetrate living tissue essentially without any strong direct interactions because the living tissue is essentially “transparent” to the magnetic fields themselves. These pulses are inductively coupled across space to the structures within living tissues that have conductive paths, for example around the cell membrane in the paracellular space, or around organelles within cells. These conductive paths within the tissue act as the “secondary” coil of what can essentially be viewed as an air-core electrical transformer, the primary coil being the external PEMF coil.
Based on the well-understood Law of Induction, one of the four classical Maxwell Equations, electrical currents are induced in and around the cells within the living tissue within the conductive paths in and around cells. This takes the form of ions in solution being forced to move, driven by the induced fields [1] .
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PEMF using slew rate or electromagnetic induction allows the electrical stimulation of deep living tissues without requiring the use of invasive electrodes. For this reason induction PEMF has advantages over the much more common use of direct conductively coupled electrical stimulation, sometimes designated TENS, but unlike TENS it does not have to overcome the resistance of skin tissue, and the induced fields generated in deep tissue by such PEMF systems are more widely and more uniformly distributed across the tissues being stimulated.One final advantage of PEMF over more general forms of microcurrent stimulation is that when properly applied, high slew rate PEMF pulses are transformed into induced electrical signals that themselves mimic known electrical signals within living tissues, such as those involved in excitation-contraction coupling of striated muscle (skeletal and cardiac muscle), therefore PEMF can take advantage of native signal reception and amplification mechanisms within living cells/tissues, thus requiring only very low stimulation energy to achieve the desired cellular response.
Observations and mathematical models suggest that one of the primary anti-inflammatory mechanisms of ICES is via the Calcium-Calmodulin (Ca2+/CaM) dependent nitric-oxide synthase pathway [2,5,7-9,17-21]. Specifically, it is hypothesized that electromagnetic pulses of appropriate parameters will preferentially induce calcium binding to CaM [7]
[1] Hubbard DK, Dennis R. Pain Relief and Tissue Healing Using PEMF Therapy: A Review of Stimulation Waveform Effects. Asia Heal. Care J. 2012; 1:26-35.
Research Proven Benefits of Higher Slew Rate PEMF
The concept of using pulsed electromagnetic fields (PEMF) has been explored as a clinical therapeutic since the 1950’s [12-14,23-25]. Since then, PEMF has been used to treat critical bone-gap defects (including spinal non-fusion), wound healing, inflammation, as well as various psychiatric disorders [1-3,6,7,9-16,20,22,25-64]
Nerve regeneration is also thought to be subject to similar signaling mechanisms that induce accelerated healing and repair as it was shown that non-depolarizing electromagnetic pulses could improve nerve lesion healing. Further studies showed that inflammatory factors could be reduced in tissue inflammation in humans post operatively [10,11]
More recently, proper slew rate PEMF has been studied in terms of behavioural modulations—specifically the effects of slew rate PEMF on bipolar- disorder, autism spectral disorder (ASD), Alzheimer’s, and Parkinson’s disease [29-37,46]
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Given that all biochemical interactions from enzymes binding ligands to ions flowing through membranes are driven by electrostatic interactions, it follows that a rapidly changing electromagnetic field should induce flow of current in tissues in the form of movement of ions that could have effects on the binding interactions of biochemical compounds. It is also very well established that tissues are constantly exposed to electrical fields, and that electrical fields play a key role in bio-signaling.
Research shows inductive PEMF should only work within a very specific range of stimulation parameters [7,18,19], namely those that induce signals that can be interpreted by existing signaling mechanisms within cells and tissues Our research in muscle tissue engineering has established similar results, showing that only in a particular range of stimulation parameters can one successfully provide signals to which tissues will respond in a favourable way. Herein, we seek to provide objective evidence that ICES, when applied appropriately, can provide significant and repeatable anti-inflammatory effects in an acute inflammation animal model
Pilla A.A, Muehsam D.J, Markov M.S, Sisken B.F. EMF signals and ion/ligand binding kinetics: prediction of bioeffective waveform parameters. Bioelectrochemistry and Bioenergetics. 1999; 48
Pilla A.A., Muehsam D.J., Markov M.S.. A dynamical systems/Larmor precession model for weak magnetic field bioeffects: Ion binding and orientation of bound water molecules.
Bioelectrochemistry and Bioenergetics. 1997; 43(2)DOI
Muehsam David J., Pilla Arthur A.. A Lorentz model for weak magnetic field bioeffects: Part II-Secondary transduction mechanisms and measures of reactivity. Bioelectromagnetics. 2009; 30(6)DOI
Observations and mathematical models suggest that one of the primary anti-inflammatory mechanisms of ICES is via the Calcium-Calmodulin (Ca2+/CaM) dependent nitric-oxide synthase pathway [2,5,7-9,17-21]. Specifically, it is hypothesized that electromagnetic pulses of appropriate parameters will preferentially induce calcium binding to CaM [7]
[1] Hubbard DK, Dennis R. Pain Relief and Tissue Healing Using PEMF Therapy: A Review of Stimulation Waveform Effects. Asia Heal. Care J. 2012; 1:26-35.
Research Proven Benefits of Higher Slew Rate PEMF
The concept of using pulsed electromagnetic fields (PEMF) has been explored as a clinical therapeutic since the 1950’s [12-14,23-25]. Since then, PEMF has been used to treat critical bone-gap defects (including spinal non-fusion), wound healing, inflammation, as well as various psychiatric disorders [1-3,6,7,9-16,20,22,25-64]
Nerve regeneration is also thought to be subject to similar signaling mechanisms that induce accelerated healing and repair as it was shown that non-depolarizing electromagnetic pulses could improve nerve lesion healing. Further studies showed that inflammatory factors could be reduced in tissue inflammation in humans post operatively [10,11]
More recently, proper slew rate PEMF has been studied in terms of behavioural modulations—specifically the effects of slew rate PEMF on bipolar- disorder, autism spectral disorder (ASD), Alzheimer’s, and Parkinson’s disease [29-37,46]
---
Given that all biochemical interactions from enzymes binding ligands to ions flowing through membranes are driven by electrostatic interactions, it follows that a rapidly changing electromagnetic field should induce flow of current in tissues in the form of movement of ions that could have effects on the binding interactions of biochemical compounds. It is also very well established that tissues are constantly exposed to electrical fields, and that electrical fields play a key role in bio-signaling.
Research shows inductive PEMF should only work within a very specific range of stimulation parameters [7,18,19], namely those that induce signals that can be interpreted by existing signaling mechanisms within cells and tissues Our research in muscle tissue engineering has established similar results, showing that only in a particular range of stimulation parameters can one successfully provide signals to which tissues will respond in a favourable way. Herein, we seek to provide objective evidence that ICES, when applied appropriately, can provide significant and repeatable anti-inflammatory effects in an acute inflammation animal model
Pilla A.A, Muehsam D.J, Markov M.S, Sisken B.F. EMF signals and ion/ligand binding kinetics: prediction of bioeffective waveform parameters. Bioelectrochemistry and Bioenergetics. 1999; 48
Pilla A.A., Muehsam D.J., Markov M.S.. A dynamical systems/Larmor precession model for weak magnetic field bioeffects: Ion binding and orientation of bound water molecules.
Bioelectrochemistry and Bioenergetics. 1997; 43(2)DOI
Muehsam David J., Pilla Arthur A.. A Lorentz model for weak magnetic field bioeffects: Part II-Secondary transduction mechanisms and measures of reactivity. Bioelectromagnetics. 2009; 30(6)DOI
Beginnings
The systematic study of the effects of electrical and magnetic fields on living and dead tissues began with Galvani in the late 18th century, whose research led to the discovery that one of the primary methods of information transfer within nerve and muscle tissues is via electrical pathways.
The systematic study of the effects of electrical and magnetic fields on living and dead tissues began with Galvani in the late 18th century, whose research led to the discovery that one of the primary methods of information transfer within nerve and muscle tissues is via electrical pathways.
In the middle of the 20th century, it was discovered that bone is piezoelectric in nature, and therefore was hypothesized to also transduce information electrically [23,24]. Soon thereafter, many experiments demonstrated that directly-applied electrical currents can be employed to induce bone formation and remodeling [12-14,25]. One problem with these early methods of direct electrical stimulation of bone tissue was that they required the implantation of electrodes into and around the bones to be stimulated. The deeply invasive nature of direct electrical stimulation of bone lead to the development of non-invasive methods, such as the use of induced electrical fields. These inductive methods employ magnetic fields from external magnets or solenoids that change over time to induce the desired electrical fields within the tissues, based on the well- understood Faraday’s Law of Induction [66]. Electrical fields induced in this non-invasive manner were subsequently shown to be effective in eliciting accelerated bone formation and healing [12].
Delicate Balance - Need enough but avoid heating/depolarization
PEMF relies on generation of local potential gradients and electric currents that would mimic bone electrochemical responses to load [14,15]. Achieving a delicate balance between the local electrical currents sufficiently high to trigger biological responses without introducing undesirable heating effects (to avoid diathermy) is a challenging bioengineering problem, approached either by a direct current application through skin contact electrodes (“capacitive coupling”) or by a contact-less “inductive coupling”, as used in our work [16]. This raises an important question about the PEMF safe dose required for achieving measurable effects in vivo in a mammalian model of osteoporosis that this study is designed to address.
Delicate Balance - Need enough but avoid heating/depolarization
PEMF relies on generation of local potential gradients and electric currents that would mimic bone electrochemical responses to load [14,15]. Achieving a delicate balance between the local electrical currents sufficiently high to trigger biological responses without introducing undesirable heating effects (to avoid diathermy) is a challenging bioengineering problem, approached either by a direct current application through skin contact electrodes (“capacitive coupling”) or by a contact-less “inductive coupling”, as used in our work [16]. This raises an important question about the PEMF safe dose required for achieving measurable effects in vivo in a mammalian model of osteoporosis that this study is designed to address.
8-4. Mechanisms of action
**Mechanism 1**Specific - Calcium-Calmodulin (Ca2+/CaM) dependent nitric-oxide synthase pathway [2,5,7-9,17-21]. Specifically, it is hypothesized that electromagnetic pulses of appropriate parameters will preferentially induce calcium binding to CaM
PEMF stimulation fine-tunes growth factors in many ways, but one of the best-understood is by increasing nitric oxide production. Calmodulin (CaM) is a messenger protein in the cell that binds calcium. It mediates various biologic processes. Once CaM binds to calcium (a process PEMF therapy increases by supporting the necessary electrical charge activity), the resulting cascade catalyzes the release of nitric oxide, and therefore improves growth factors.
**Mechanism 2** - Adenosine - A2A receptors - cAMP - anti-inflammatory
- Reverse Piezoelectric Effect - microvibrations!
- Microcurrents interrupt pain signal. Faster slew rates could lead to more significant pain relief by disrupting pain transmission at a quicker rate.
- Cell membrane one way rectifier - ion transport
- Cell receptors like A2A
- Increases ATP 400%
- Nitric Oxide and increased microcirculation
- Electroporesis - Increased cell permeability may occur, allowing for improved nutrient uptake and waste removal. Cells Breathing Better... Oxygen nutrients in easier
- Catalyst chemical reactions.
- Exercise Mimetic - LOAD/STRESS PIEZOELECTRIC. Circuits are in ions in paramembrane space. Receptors on Cell membrane that detect this ionic movement and sense it as normal exercise.
- Healing is voltage salamander studies
Crystalline Arrangements are the rule and not the exception in living systems. So MUSCLES, TENDONS, Bones, myelin, muscle, sensory organs and even cell membrane crystalline and therefore piezoelectric properties.
Virtually all the tissues in the body produce an electric field when they are stretched or compressed = ENERGY! These oscillating fields correspond precisely to the input stressors which mean they contain the information. This information is electrically and electronically conducted through the living matrix.
The electric fields produced during movements are widely considered to provide the information that directs the activities of generative cells (Bassett). These osteoblasts, myoblasts, fibroblasts and other 'stem' cells help to reform and heal tissues so the body can adapt to ways the body is used.
Electric fields generated during movement (streaming or piezoelectric potentials) or PEMF signal cells (fibroblasts in connective tissue, osteoblasts in bones) to lay down collagen in the direction of tension/stress and therefore strengthen the tissue. With less loading or movement, the electric fields are weaker and less frequent, and the cells resorb collagen (Bassett 1968).
-Cells Breathing Better... Oxygen nutrients in easier,
- Chronic Inflammation
8 Hour test - carrageenan challenge to lower inflammation.
60% as effective as a megadose of steroids.
No measurable effect on inflammation.
Most exciting results he had seen.
The fundamental action of PEMF appears to be the reduction of pathologic chronic inflammation to enable normal tissue recovery. So, it is better to think of PEMF as something that improves the physiologic conditions to promote normal healing, rather than as an external force that “heals something”. Thinking along these lines, my conceptualization is that healing in joints is facilitated by PEMF by suppressing pathologic inflammation and swelling. This allows normal healing processes to occur. But the “normal” healing rate for joint tissues is extremely slow, so it is not likely that PEMF would drive the healing process quickly in terms of joint healing. PEMF just helps to facilitate what is normally a slow, natural process.
PEMF exposure results in increased expression of adenosine receptors in a variety of cells and tissues. Activation of these receptors results in reduction of prostaglandins , reduction of inflammatory cytokines in alignment with published studies of decrease pain and inflammation and increased wound healing.
**Mechanism 1**Specific - Calcium-Calmodulin (Ca2+/CaM) dependent nitric-oxide synthase pathway [2,5,7-9,17-21]. Specifically, it is hypothesized that electromagnetic pulses of appropriate parameters will preferentially induce calcium binding to CaM
PEMF stimulation fine-tunes growth factors in many ways, but one of the best-understood is by increasing nitric oxide production. Calmodulin (CaM) is a messenger protein in the cell that binds calcium. It mediates various biologic processes. Once CaM binds to calcium (a process PEMF therapy increases by supporting the necessary electrical charge activity), the resulting cascade catalyzes the release of nitric oxide, and therefore improves growth factors.
**Mechanism 2** - Adenosine - A2A receptors - cAMP - anti-inflammatory
- Reverse Piezoelectric Effect - microvibrations!
- Microcurrents interrupt pain signal. Faster slew rates could lead to more significant pain relief by disrupting pain transmission at a quicker rate.
- Cell membrane one way rectifier - ion transport
- Cell receptors like A2A
- Increases ATP 400%
- Nitric Oxide and increased microcirculation
- Electroporesis - Increased cell permeability may occur, allowing for improved nutrient uptake and waste removal. Cells Breathing Better... Oxygen nutrients in easier
- Catalyst chemical reactions.
- Exercise Mimetic - LOAD/STRESS PIEZOELECTRIC. Circuits are in ions in paramembrane space. Receptors on Cell membrane that detect this ionic movement and sense it as normal exercise.
- Healing is voltage salamander studies
Crystalline Arrangements are the rule and not the exception in living systems. So MUSCLES, TENDONS, Bones, myelin, muscle, sensory organs and even cell membrane crystalline and therefore piezoelectric properties.
Virtually all the tissues in the body produce an electric field when they are stretched or compressed = ENERGY! These oscillating fields correspond precisely to the input stressors which mean they contain the information. This information is electrically and electronically conducted through the living matrix.
The electric fields produced during movements are widely considered to provide the information that directs the activities of generative cells (Bassett). These osteoblasts, myoblasts, fibroblasts and other 'stem' cells help to reform and heal tissues so the body can adapt to ways the body is used.
Electric fields generated during movement (streaming or piezoelectric potentials) or PEMF signal cells (fibroblasts in connective tissue, osteoblasts in bones) to lay down collagen in the direction of tension/stress and therefore strengthen the tissue. With less loading or movement, the electric fields are weaker and less frequent, and the cells resorb collagen (Bassett 1968).
-Cells Breathing Better... Oxygen nutrients in easier,
- Chronic Inflammation
8 Hour test - carrageenan challenge to lower inflammation.
60% as effective as a megadose of steroids.
No measurable effect on inflammation.
Most exciting results he had seen.
The fundamental action of PEMF appears to be the reduction of pathologic chronic inflammation to enable normal tissue recovery. So, it is better to think of PEMF as something that improves the physiologic conditions to promote normal healing, rather than as an external force that “heals something”. Thinking along these lines, my conceptualization is that healing in joints is facilitated by PEMF by suppressing pathologic inflammation and swelling. This allows normal healing processes to occur. But the “normal” healing rate for joint tissues is extremely slow, so it is not likely that PEMF would drive the healing process quickly in terms of joint healing. PEMF just helps to facilitate what is normally a slow, natural process.
PEMF exposure results in increased expression of adenosine receptors in a variety of cells and tissues. Activation of these receptors results in reduction of prostaglandins , reduction of inflammatory cytokines in alignment with published studies of decrease pain and inflammation and increased wound healing.
ATP
There is a significant need to increase ATP production and improve mitochondrial function, and PEMFs are the ideal tool to do so. It has been shown that using PEMFs for only 20 minutes can stimulate ATP production (Zhang S) up to 600%, averaging 111-241%v
Zhang S, Clark M, Liu X, et al. The Effects of Bio-inspired Electromagnetic Fields on Healthy Enhancement with Case Studies. Emerging Science Journal 2019 Dec;3(6):369-381.
There is a significant need to increase ATP production and improve mitochondrial function, and PEMFs are the ideal tool to do so. It has been shown that using PEMFs for only 20 minutes can stimulate ATP production (Zhang S) up to 600%, averaging 111-241%v
Zhang S, Clark M, Liu X, et al. The Effects of Bio-inspired Electromagnetic Fields on Healthy Enhancement with Case Studies. Emerging Science Journal 2019 Dec;3(6):369-381.
Non-Depolarizing Electromagnetic Fields
With the advent of inductive stimulation methods came the study of the effects of non-depolarizing electromagnetic fields on tissues other than bone. Non-depolarizing electric fields are those which are too low to induce overt depolarization of the cell membrane as in the case of an action potential, but strong enough to presumably have other effects on molecular mechanisms within cells and in the extracellular space.
With the advent of inductive stimulation methods came the study of the effects of non-depolarizing electromagnetic fields on tissues other than bone. Non-depolarizing electric fields are those which are too low to induce overt depolarization of the cell membrane as in the case of an action potential, but strong enough to presumably have other effects on molecular mechanisms within cells and in the extracellular space.
Types of biologically relevant signals
There are three key levels of signals that need to be specified in order to properly define the waveform parameters that are to be used when inductively stimulating:
1) Current flowing into the coils from the stimulation unit. This is the original driving signal that is produced by the electronic circuit within the PEMF device to drive the coil that will then produce the magnetic field.
==> The induction of electrical fields within tissues requires magnetic fields that vary in time, and typically this is accomplished using a computer or a microcontroller-based platform to drive current waveforms through solenoid coils. To induce the desired electrical fields it is essential to control the slew-rate (rate of change or first time derivative of the magnetic flux) of the signal. Thus, it is of utmost importance that the primary driving electronics have adequate dynamic performance.
2) The time-varying magnetic flux in and around the coils resulting from the electrical current driving the wire coils.
==> Faraday’s law of induction shows that the induced circular electric field in a conducting surface is proportional to the inverse of the rate of change of the magnetic flux (defined as the magnetic field strength times the area through which it is passing). The key parameters involved with the induced electric field are the rate of change of the magnetic field (i.e. dB/dt, which is the first time derivative of the magnetic flux B) and the radius around which one examines the field of interest. Specifically, the larger the rate of change of the magnetic field, the larger the possible induced electric field. Maxwell’s relationship explains why the driving electronics must have good dynamic performance: to provide adequate magnetic flux slew rate to induce the desired electric field in the tissue. For a given magnetic flux change, the larger the radius of interest (up to the inner radius of the stimulating coil), the larger the induced field, and the smaller the radius, the smaller the induced field.
For the most part, the second level signal—magnetic flux—is the most relevant signal to specify because it is prone to deviate from theoretical values when calculated based upon the presumed driver circuit performance, it is readily measured using modern analog signal Hall effect sensors, and when measured accurately yields good estimates of the induced field within the tissues
There are three key levels of signals that need to be specified in order to properly define the waveform parameters that are to be used when inductively stimulating:
1) Current flowing into the coils from the stimulation unit. This is the original driving signal that is produced by the electronic circuit within the PEMF device to drive the coil that will then produce the magnetic field.
==> The induction of electrical fields within tissues requires magnetic fields that vary in time, and typically this is accomplished using a computer or a microcontroller-based platform to drive current waveforms through solenoid coils. To induce the desired electrical fields it is essential to control the slew-rate (rate of change or first time derivative of the magnetic flux) of the signal. Thus, it is of utmost importance that the primary driving electronics have adequate dynamic performance.
2) The time-varying magnetic flux in and around the coils resulting from the electrical current driving the wire coils.
==> Faraday’s law of induction shows that the induced circular electric field in a conducting surface is proportional to the inverse of the rate of change of the magnetic flux (defined as the magnetic field strength times the area through which it is passing). The key parameters involved with the induced electric field are the rate of change of the magnetic field (i.e. dB/dt, which is the first time derivative of the magnetic flux B) and the radius around which one examines the field of interest. Specifically, the larger the rate of change of the magnetic field, the larger the possible induced electric field. Maxwell’s relationship explains why the driving electronics must have good dynamic performance: to provide adequate magnetic flux slew rate to induce the desired electric field in the tissue. For a given magnetic flux change, the larger the radius of interest (up to the inner radius of the stimulating coil), the larger the induced field, and the smaller the radius, the smaller the induced field.
For the most part, the second level signal—magnetic flux—is the most relevant signal to specify because it is prone to deviate from theoretical values when calculated based upon the presumed driver circuit performance, it is readily measured using modern analog signal Hall effect sensors, and when measured accurately yields good estimates of the induced field within the tissues
3) The induced electric field in the tissue volume resulting from the time-varying magnetic flux generated by the coils.
Thirdly, it is necessary to discuss the induced electric field—specifically with regard to the tissue volumes of interest. The induced field can be calculated using the equation shown here**.
Schaefer, D.J., Bourland, J.D. and Nyenhuis, J.A. (2000), Review of Patient Safety in Time-Varying Gradient Fields. J. Magn. Reson. Imaging, 12: 20-29. .
In the case of eddy currents within a tissue, one can consider the conducting pathways to be represented by the fluid in the pericellular space, just outside the cell membrane and between cells and thus, circular pathways around cells are those of interest.
If one considers thermal noise averaging, and cellular response, then the predicted threshold induced field for a measureable response is on the order of 10^-3 – 10^-5 V/m*
Weaver JC, Astumian RD. The response of living cells to very weak electric fields: the thermal noise limit. Science. 1990 Jan 26;247(4941):459-62
Assuming the low-end of the stimulation threshold to be approximately 10-5 V/m, the smallest signal that one might expect to use and still observe a physiological response is approximately 4 T/s.
Area of Usefulness ==> at least 4 T/s
I've been doing a lot of calculations, and if the ideal rise time is between 5t/s and 30 t/s, then a coil design that keeps that range is fairly difficult to design. Next to the coil there will be a rise time faster than 30t/s and 8" away the rise time will be below 2t/s. This makes every coil have an "area of usefulness" where the rise time is between the two extremes (this is obviously something where more research would be helpful). It almost make sense to make the "area of usefulness" tunable so that people can set it close to the coil for surface wounds, and far from the coil for deeper treatments
==> The best coil design will spread the rate of change out as evenly as possible
Large Coil
Capacitive Layer
Right Signal
Inductance
Radius
Current
Voltage
Resistance
Inner winding capacitance
Pulse Duration
Thirdly, it is necessary to discuss the induced electric field—specifically with regard to the tissue volumes of interest. The induced field can be calculated using the equation shown here**.
Schaefer, D.J., Bourland, J.D. and Nyenhuis, J.A. (2000), Review of Patient Safety in Time-Varying Gradient Fields. J. Magn. Reson. Imaging, 12: 20-29. .
In the case of eddy currents within a tissue, one can consider the conducting pathways to be represented by the fluid in the pericellular space, just outside the cell membrane and between cells and thus, circular pathways around cells are those of interest.
If one considers thermal noise averaging, and cellular response, then the predicted threshold induced field for a measureable response is on the order of 10^-3 – 10^-5 V/m*
Weaver JC, Astumian RD. The response of living cells to very weak electric fields: the thermal noise limit. Science. 1990 Jan 26;247(4941):459-62
Assuming the low-end of the stimulation threshold to be approximately 10-5 V/m, the smallest signal that one might expect to use and still observe a physiological response is approximately 4 T/s.
Area of Usefulness ==> at least 4 T/s
I've been doing a lot of calculations, and if the ideal rise time is between 5t/s and 30 t/s, then a coil design that keeps that range is fairly difficult to design. Next to the coil there will be a rise time faster than 30t/s and 8" away the rise time will be below 2t/s. This makes every coil have an "area of usefulness" where the rise time is between the two extremes (this is obviously something where more research would be helpful). It almost make sense to make the "area of usefulness" tunable so that people can set it close to the coil for surface wounds, and far from the coil for deeper treatments
==> The best coil design will spread the rate of change out as evenly as possible
Large Coil
Capacitive Layer
Right Signal
Inductance
Radius
Current
Voltage
Resistance
Inner winding capacitance
Pulse Duration
***Case Short Ramp Duration***
Note that for short ramp durations, mean nerve stimulation thresholds expressed in dB/dt can become large. However, the safety margin between nerve stimulation and cardiac stimulation increases as ramp duration is reduced.
Note that for short ramp durations, mean nerve stimulation thresholds expressed in dB/dt can become large. However, the safety margin between nerve stimulation and cardiac stimulation increases as ramp duration is reduced.
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Formica, Domenico & Silvestri, Sergio. (2004). Biological effects of exposure to magnetic resonance imaging: An overview. Biomedical engineering online. 3. 11. 10.1186/1475-925X-3-11.
IEC. Particular requirements for the safety of magnetic resonance equipment for medical diagnosis. In: Diagnostic imaging equipment, publication IEC 60601-2-33, medical electrical equipment, Part 2. International Electrotechnology Commission, International Electrotechnical Commission (IEC), 3, rue de Varembé, P.O. Box 131, CH-1211 Geneva 20, Switzerland, 1995.
IEC. Particular requirements for the safety of magnetic resonance equipment for medical diagnosis. In: Diagnostic imaging equipment, publication IEC 60601-2-33, medical electrical equipment, Part 2. International Electrotechnology Commission, International Electrotechnical Commission (IEC), 3, rue de Varembé, P.O. Box 131, CH-1211 Geneva 20, Switzerland, 1995.
Note on Slew Rate vs Resonance
Therefore many Slew rate PEMF technologies do not take advantage of the inherent natural mechanisms of biological signal amplification, preferring instead to use a brute-force approach to coerce the target tissue toward the desired response rather than employing high fidelity signals that work with innate biological filters and amplifiers
Therefore many Slew rate PEMF technologies do not take advantage of the inherent natural mechanisms of biological signal amplification, preferring instead to use a brute-force approach to coerce the target tissue toward the desired response rather than employing high fidelity signals that work with innate biological filters and amplifiers
Figure 4.Representative ICES waveforms. A.) Sinusoidal waveforms have smoothly varying edges, and can also be pulsed at high frequencies to produce PRF signals. B.) Trapezoidal and square waveforms represent waveforms with large rising and falling edge slopes and non-changing peaks and troughs. C.) Asymmetric pulses, such as the saw-tooth waveform shown, represent waveforms that have large rising and/or falling edge slopes, but provide non-symmetric induced electric fields within tissues of interest. A description of the numbered portions above can be found in Table 1..
Trapezoidal and triangular magnetic pulses can be generated individually with long periods of inactivity between pulses, but it is possible by this approach to generate very large induced electric fields by driving the trapezoidal waveforms with very steep rising and falling edges, that is, incorporating large slew rates to each edge of each trapezoidal or triangular pulse. Such signals are easily capable of producing 1.5 V/m induced signals while keeping peak magnetic field strength well below 0.1 T provided the pulse can be delivered in a short enough time (approximately 100 µs).
Frequency modulated signals provide an alternative method for producing high slew-rate signals by encoding low frequency signals in high frequency (1-27.12 MHz) sinusoidal carrier waves.
Demodulation allows these high frequency bursts to have brain entrainment effects.
Trapezoidal and triangular magnetic pulses can be generated individually with long periods of inactivity between pulses, but it is possible by this approach to generate very large induced electric fields by driving the trapezoidal waveforms with very steep rising and falling edges, that is, incorporating large slew rates to each edge of each trapezoidal or triangular pulse. Such signals are easily capable of producing 1.5 V/m induced signals while keeping peak magnetic field strength well below 0.1 T provided the pulse can be delivered in a short enough time (approximately 100 µs).
Frequency modulated signals provide an alternative method for producing high slew-rate signals by encoding low frequency signals in high frequency (1-27.12 MHz) sinusoidal carrier waves.
Demodulation allows these high frequency bursts to have brain entrainment effects.
**SLEW RATE STUDIES**
Orthofix Physiostim CLASSIC vs HSR (High Slew Rate)
1) A comparison of alendronate to varying magnitude PEMF in mitigating bone loss and altering bone remodeling in skeletally mature osteoporotic rats
***High Slew Rate - Burst - but not too high (30 - 100 ideal dose response)
https://www.sciencedirect.com/science/article/abs/pii/S8756328220305494
http://scalarsymphony.health/articles-pemf/A%20comparison%20of%20alendronate%20to%20varying%20magnitude%20PEMF%20in%20mitigating%20bone%20loss%20and%20altering%20bone%20remodeling%20in%20skeletally%20mature%20osteoporotic%20rats.pdf
Trabecular bone, is porous bone composed of trabeculated bone tissue. It can be found at the ends of long bones like the femur, where the bone is actually not solid but is full of holes connected by thin rods and plates of bone tissue.
3.85 kHz as equal to the fundamental frequency of the quasi-rectangular waveform of the commercial device (Physio-Stim™, which the study was designed to emulate) and four discrete B field magnitudes of 0.41 mT, 1.2 mT, 4.1 mT and 12.4 mT, corresponding to dB/dt field magnitudes of 10 T/s (characteristic of Physio-Stim™), 30 T/s, 100 T/s and 300 T/s respectively
The observed PEMF dose dependency in tested outcomes was not a simple relationship; rather there appeared to be a range of PEMF slew rate that provided better bone outcomes than others. In this study, the middle range of PEMF slew rate of 30–100 T/s (having similar 3850 Hz frequency sinusoids in bursts of 15 Hz) more effectively reduced trabecular bone loss in OVX rats than PEMF treatments with higher or lower slew rates.
1) A comparison of alendronate to varying magnitude PEMF in mitigating bone loss and altering bone remodeling in skeletally mature osteoporotic rats
***High Slew Rate - Burst - but not too high (30 - 100 ideal dose response)
https://www.sciencedirect.com/science/article/abs/pii/S8756328220305494
http://scalarsymphony.health/articles-pemf/A%20comparison%20of%20alendronate%20to%20varying%20magnitude%20PEMF%20in%20mitigating%20bone%20loss%20and%20altering%20bone%20remodeling%20in%20skeletally%20mature%20osteoporotic%20rats.pdf
Trabecular bone, is porous bone composed of trabeculated bone tissue. It can be found at the ends of long bones like the femur, where the bone is actually not solid but is full of holes connected by thin rods and plates of bone tissue.
3.85 kHz as equal to the fundamental frequency of the quasi-rectangular waveform of the commercial device (Physio-Stim™, which the study was designed to emulate) and four discrete B field magnitudes of 0.41 mT, 1.2 mT, 4.1 mT and 12.4 mT, corresponding to dB/dt field magnitudes of 10 T/s (characteristic of Physio-Stim™), 30 T/s, 100 T/s and 300 T/s respectively
The observed PEMF dose dependency in tested outcomes was not a simple relationship; rather there appeared to be a range of PEMF slew rate that provided better bone outcomes than others. In this study, the middle range of PEMF slew rate of 30–100 T/s (having similar 3850 Hz frequency sinusoids in bursts of 15 Hz) more effectively reduced trabecular bone loss in OVX rats than PEMF treatments with higher or lower slew rates.
HSR - High Slew Rate 30 T/s > 10 T/s
2) Pulsed Electromagnetic Field Enhances Healing of a Meniscal Tear and Mitigates Posttraumatic Osteoarthritis in a Rat Model
https://www.researchgate.net/publication/362008725_Pulsed_Electromagnetic_Field_Enhances_Healing_of_a_Meniscal_Tear_and_Mitigates_Posttraumatic_Osteoarthritis_in_a_Rat_Model/link/62d3be92d351bd24f51e8c58/download
Among the 3 groups, HSR PEMF treatment demonstrated stronger anti-inflammatory effects by significantly downregulating the secretion levels of IL-1b and TNF-a in the synovium and meniscus.
In contrast to classic PEMF treatment (three hrs/day), HSR PEMF treatment (one hr/day) achieved similar
promoting effects on bone formation.
30 T/s > 10 T/s
Slew rate is defined as the rate of B-field change over time and calculated per the following equation: slew rate = dB/dt. The classic signal has been approved by the FDA to manage long bone nonunions. 15 The HSR signal has the same pulse and burst frequencies as the classic signal but with a higher slew rate. Namely, the HSR signal could deliver a greater amount of energy per unit time.
3) High slew rate pulsed electromagnetic field enhances bone consolidation and shortens daily treatment duration in distraction osteogenesis
30 T/s> 10 T/s
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8696558/
By comparison, the HSR signal (three hrs/day) treatment group achieved the best healing outcome, in that endochondral ossification and bone consolidation were enhanced. In addition, HSR signal treatment (one one hr/day) had similar effects to treatment using the classic signal (three three hrs/day), indicating that treatment duration could be significantly shortened with the HSR signal.
https://boneandjoint.org.uk/Article/10.1302/2046-3758.1012.BJR-2021-0274.R1/pdf
4) A novel pulsed electromagnetic field promotes distraction osteogenesis via enhancing osteogenesis and angiogenesis in a rat model 30 >10 T/s
https://www.researchgate.net/publication/346483744_A_novel_pulsed_electromagnetic_field_promotes_distraction_osteogenesis_via_enhancing_osteogenesis_and_angiogenesis_in_a_rat_model
Our study showed that new high slew rate PEMF signal could promote osteogenesis and angiogenesis in a rat model of DO, which provides insight into the development of new noninvasive mean to accelerate bone formation in the DO process.
5) 18.8 T/s Slew Rate for Microcirculation
https://onlinelibrary.wiley.com/doi/epdf/10.1016/S0736-0266%2803%2900157-8
2) Pulsed Electromagnetic Field Enhances Healing of a Meniscal Tear and Mitigates Posttraumatic Osteoarthritis in a Rat Model
https://www.researchgate.net/publication/362008725_Pulsed_Electromagnetic_Field_Enhances_Healing_of_a_Meniscal_Tear_and_Mitigates_Posttraumatic_Osteoarthritis_in_a_Rat_Model/link/62d3be92d351bd24f51e8c58/download
Among the 3 groups, HSR PEMF treatment demonstrated stronger anti-inflammatory effects by significantly downregulating the secretion levels of IL-1b and TNF-a in the synovium and meniscus.
In contrast to classic PEMF treatment (three hrs/day), HSR PEMF treatment (one hr/day) achieved similar
promoting effects on bone formation.
30 T/s > 10 T/s
Slew rate is defined as the rate of B-field change over time and calculated per the following equation: slew rate = dB/dt. The classic signal has been approved by the FDA to manage long bone nonunions. 15 The HSR signal has the same pulse and burst frequencies as the classic signal but with a higher slew rate. Namely, the HSR signal could deliver a greater amount of energy per unit time.
3) High slew rate pulsed electromagnetic field enhances bone consolidation and shortens daily treatment duration in distraction osteogenesis
30 T/s> 10 T/s
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8696558/
By comparison, the HSR signal (three hrs/day) treatment group achieved the best healing outcome, in that endochondral ossification and bone consolidation were enhanced. In addition, HSR signal treatment (one one hr/day) had similar effects to treatment using the classic signal (three three hrs/day), indicating that treatment duration could be significantly shortened with the HSR signal.
https://boneandjoint.org.uk/Article/10.1302/2046-3758.1012.BJR-2021-0274.R1/pdf
4) A novel pulsed electromagnetic field promotes distraction osteogenesis via enhancing osteogenesis and angiogenesis in a rat model 30 >10 T/s
https://www.researchgate.net/publication/346483744_A_novel_pulsed_electromagnetic_field_promotes_distraction_osteogenesis_via_enhancing_osteogenesis_and_angiogenesis_in_a_rat_model
Our study showed that new high slew rate PEMF signal could promote osteogenesis and angiogenesis in a rat model of DO, which provides insight into the development of new noninvasive mean to accelerate bone formation in the DO process.
5) 18.8 T/s Slew Rate for Microcirculation
https://onlinelibrary.wiley.com/doi/epdf/10.1016/S0736-0266%2803%2900157-8
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Pulse in Bob Dennis Rabbit Bone Study
Narrow “square” electrical pulses from the PEMF pulse generator circuit yielded skewed triangular magnetic waveforms, as shown. This magnetic waveform is typical, resulting from a 100 micro-second current pulse applied to the PEMF coil in a short cuff, and measured using an analog Hall effect sensor. Note that the rise time corresponds to the electrical current pulse applied the coils (0 μs to 100 μs), while the fall-off time occurs while the coil current drains to ground potential 
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Magnetic Magic
Here is the typical Magnetic Magic pulse. It is 1mT per division up and down and 100uS per division left to right. The curved rise and fall are part of what makes the pulse have good spectral content. You can also see that if the line was straight instead of curved it would be closer to 50 T/s. So technically a portion of the pulse is around 50 T/s but averaged out it is 30 T/s 
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HIGH SLEW RATE PULSE
Robert Dennis Paper - Part 1
https://www.researchgate.net/publication/340330953_Inductively_Coupled_Electrical_Stimulation_-_Part_I_Overview_and_First_Observations
Dennis Robert. Inductively Coupled Electrical Stimulation - Part I: Overview and First Observations. The Journal of Science and Medicine. 2019; 1
***Another study that mentions slew rate - Part 2
BOB DENNIS RABBIT STUDY-- Conclusion
The key parameter for biological effectiveness of PEMF was determined to be magnetic slew rate (dB/dt), and the minimum threshold of this parameter for clinical effectiveness for regeneration of bone tissue after orthopedic injury was found to be ~ 100 kG/s (10 T/s). This magnetic slew rate, when sustained for 100 μs at a pulse rate of 10 Hz, was found to be effective both for pain reduction as well as to induce bone regeneration in a critical defect gap
https://www.josam.org/josam/article/view/27/25#:~:text=The%20optimal%20magnetic%20waveform%20slew,%3D%3E%20100%20kG%2Fs
Dennis Robert. Inductively Coupled Electrical Stimulation - Part 2: Optimization of parameters for orthopedic injuries and pain. The Journal of Science and Medicine. 2020; 1
Robert Dennis Paper - Part 3
https://www.josam.org/josam/article/view/46
Dennis Robert. Inductively Coupled Electrical Stimulation - Part 3: PEMF Systems for use in Basic Research with Laboratory Animals and In Vitro. The Journal of Science and Medicine. 2020; 2
Robert Dennis Paper - Part 4
https://www.josam.org/josam/article/view/58
Dennis Robert, Tommerdahl Anna, Dennis Andromeda. Inductively Coupled Electrical Stimulation - Part 4: Effect of PEMF on seed germination; evidence of triphasic inverse hormesis. The Journal of Science and Medicine. 2021; 2
Robert Dennis Paper - Part 5
https://www.josam.org/josam/article/view/67
Dennis R. (2021). Inductively Coupled Electrical Stimulation - Part 5: How many types of PEMF are there? A model and Excel Calculator; 4(2):1-10.
Robert Dennis Paper - Part 6
https://www.josam.org/josam/article/view/86
Summarizing the results listed it sounds like rise times of 30t/s are more effective than 100t/s, and 10T/s ia better than 5T/s
Robert Dennis Slew Rate and Inflammation 40, 80, 120, 160 then Plateau - 160 and 120 performed sligthly better than 40 (120-160 Ideal)
https://www.josam.org/josam/article/view/38
Both studies indicate rise time (dB/dt) as a critical determinant of efficacy, a characteristic not previously cited in a literature dominated by field strength, frequency, and duration.
** Full Article Here is a paper that says the Nasa PEMF Studies showed that high rise time is critical:
https://onlinelibrary.wiley.com/doi/full/10.1002/jcp.21025
https://onlinelibrary.wiley.com/doi/full/10.1002/jcp.21025
Here is the specific quote "Of relevance, it has been recently shown that applied low-frequency magnetic fields in the range of 1 mT are capable of radical-pair amplification generated by flavin-tryptophan moieties, whereas amplitudes exceeding the hyperfine nuclear interactions limit (∼3 mT) are inefficient at doing so (62), perhaps giving insight as to the origin of the myogenic efficacy amplitude ceiling of the pulsing magnetic fields described in this report (Supplemental Fig. S3)"
Another Study with Slew Rate Windows
https://www.tandfonline.com/doi/abs/10.1080/15368378.2019.1608233
9.5 T/s Successful
https://openurl.ebsco.com/EPDB%3Agcd%3A12%3A11965132/detailv2?sid=ebsco%3Aplink%3Ascholar&id=ebsco%3Agcd%3A15247064&crl=c
Full article not found
Proof 15 T/s works
https://onlinelibrary.wiley.com/doi/full/10.1002/jor.23333
Pulsed electromagnetic field therapy improves tendon-to-bone healing in a rat rotator cuff repair model
Overall, results suggest that PEMF improves early tendon-to-bone healing specifically through an improvement of tendon mechanical properties. We speculate that PEMF treatment may increase tendon cell metabolism, in turn increasing matrix production and collagen remodeling, reflected in improved mechanical properties and increased collagen alignment. A small rotator cuff repair clinical trial utilizing a different PEMF signal demonstrated early increases in range of motion and functional scores.14 Our findings provide further evidence of improvements in mechanical properties and matrix organization, supporting further investigation into clinical use of this therapy for various PEMF waveforms.
17 T/s works
https://www.nature.com/articles/s41598-017-09892-w
15 Hz and at flux densities between 1–4 mT. Each 6 ms burst consisted of a series of 20 consecutive asymmetric pulses of 150 µs on and off duration with an approximate rise time of 17 T/s.
Pulse electromagnetic fields (PEMFs) have been shown to recruit calcium-signaling cascades common to chondrogenesis.
Chondrogenesis is the biological process through which cartilage tissue is formed and developed.
Another proof 17T/s is effective
https://www.sciencedirect.com/science/article/pii/S0142961222002988
17T/s is effective again
https://stemcellres.biomedcentral.com/articles/10.1186/s13287-020-1566-5
We provide evidence that brief exposure to low amplitude PEMFs enhanced the ability of MSCs to produce and secrete paracrine factors capable of promoting cartilage regeneration as well as protecting against adverse inflammatory conditions.
5.3 T/s Worked
https://www.researchgate.net/publication/352001966_Enhancement_of_Nerve_Regeneration_by_Selected_Electromagnetic_Signals
Study showing 2.5 T/s not working
Study showing 1.5 T/s not working
Study showing low slew rate not working
https://www.sciencedirect.com/science/article/abs/pii/S0031938417303876
3mT limit ?
This article makes it look like I should limit the field strength to under 3mt for maximum effectiveness. Have you heard that before?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6902701/
Pulsed therapeutic fields are usually more effective if less than 30 gauss (see Curie's Law and dipole saturation), and frequencies are commonly less than 100 Hz, below which they are referred to as extremely low frequency (ELF). Cell phones are several magnitudes of order larger in both considerations.
**slew rate causes damage
https://ieeexplore.ieee.org/abstract/document/4062729
**Too much slew rate makes permeable
https://www.researchgate.net/figure/The-waveform-of-the-high-dB-dt-magnetic-field-pulse-Each-magnetic-pulse-was-15-s-wide%C2%A7fig1%C2%A7316490221
Too high of a Slew Rate causes potential unhealthy PNS (Peripheral Nerve Stimulation)
https://onlinelibrary.wiley.com/doi/epdf/10.1002/cmr.10011
***Cells Can Die - Killing Yeast Cells***
Inducing 190 V/cm - 19,000 V/m - Muscle Twitch Induced.
Here is another that specifically mentions dB/dT:
https://pubmed.ncbi.nlm.nih.gov/28238117/
Horse continues to twitch after.
Robert Dennis Paper - Part 1
https://www.researchgate.net/publication/340330953_Inductively_Coupled_Electrical_Stimulation_-_Part_I_Overview_and_First_Observations
Dennis Robert. Inductively Coupled Electrical Stimulation - Part I: Overview and First Observations. The Journal of Science and Medicine. 2019; 1
***Another study that mentions slew rate - Part 2
BOB DENNIS RABBIT STUDY-- Conclusion
The key parameter for biological effectiveness of PEMF was determined to be magnetic slew rate (dB/dt), and the minimum threshold of this parameter for clinical effectiveness for regeneration of bone tissue after orthopedic injury was found to be ~ 100 kG/s (10 T/s). This magnetic slew rate, when sustained for 100 μs at a pulse rate of 10 Hz, was found to be effective both for pain reduction as well as to induce bone regeneration in a critical defect gap
https://www.josam.org/josam/article/view/27/25#:~:text=The%20optimal%20magnetic%20waveform%20slew,%3D%3E%20100%20kG%2Fs
Dennis Robert. Inductively Coupled Electrical Stimulation - Part 2: Optimization of parameters for orthopedic injuries and pain. The Journal of Science and Medicine. 2020; 1
Robert Dennis Paper - Part 3
https://www.josam.org/josam/article/view/46
Dennis Robert. Inductively Coupled Electrical Stimulation - Part 3: PEMF Systems for use in Basic Research with Laboratory Animals and In Vitro. The Journal of Science and Medicine. 2020; 2
Robert Dennis Paper - Part 4
https://www.josam.org/josam/article/view/58
Dennis Robert, Tommerdahl Anna, Dennis Andromeda. Inductively Coupled Electrical Stimulation - Part 4: Effect of PEMF on seed germination; evidence of triphasic inverse hormesis. The Journal of Science and Medicine. 2021; 2
Robert Dennis Paper - Part 5
https://www.josam.org/josam/article/view/67
Dennis R. (2021). Inductively Coupled Electrical Stimulation - Part 5: How many types of PEMF are there? A model and Excel Calculator; 4(2):1-10.
Robert Dennis Paper - Part 6
https://www.josam.org/josam/article/view/86
Summarizing the results listed it sounds like rise times of 30t/s are more effective than 100t/s, and 10T/s ia better than 5T/s
Robert Dennis Slew Rate and Inflammation 40, 80, 120, 160 then Plateau - 160 and 120 performed sligthly better than 40 (120-160 Ideal)
https://www.josam.org/josam/article/view/38
Both studies indicate rise time (dB/dt) as a critical determinant of efficacy, a characteristic not previously cited in a literature dominated by field strength, frequency, and duration.
** Full Article Here is a paper that says the Nasa PEMF Studies showed that high rise time is critical:
https://onlinelibrary.wiley.com/doi/full/10.1002/jcp.21025
https://onlinelibrary.wiley.com/doi/full/10.1002/jcp.21025
Here is the specific quote "Of relevance, it has been recently shown that applied low-frequency magnetic fields in the range of 1 mT are capable of radical-pair amplification generated by flavin-tryptophan moieties, whereas amplitudes exceeding the hyperfine nuclear interactions limit (∼3 mT) are inefficient at doing so (62), perhaps giving insight as to the origin of the myogenic efficacy amplitude ceiling of the pulsing magnetic fields described in this report (Supplemental Fig. S3)"
Another Study with Slew Rate Windows
https://www.tandfonline.com/doi/abs/10.1080/15368378.2019.1608233
9.5 T/s Successful
https://openurl.ebsco.com/EPDB%3Agcd%3A12%3A11965132/detailv2?sid=ebsco%3Aplink%3Ascholar&id=ebsco%3Agcd%3A15247064&crl=c
Full article not found
Proof 15 T/s works
https://onlinelibrary.wiley.com/doi/full/10.1002/jor.23333
Pulsed electromagnetic field therapy improves tendon-to-bone healing in a rat rotator cuff repair model
Overall, results suggest that PEMF improves early tendon-to-bone healing specifically through an improvement of tendon mechanical properties. We speculate that PEMF treatment may increase tendon cell metabolism, in turn increasing matrix production and collagen remodeling, reflected in improved mechanical properties and increased collagen alignment. A small rotator cuff repair clinical trial utilizing a different PEMF signal demonstrated early increases in range of motion and functional scores.14 Our findings provide further evidence of improvements in mechanical properties and matrix organization, supporting further investigation into clinical use of this therapy for various PEMF waveforms.
17 T/s works
https://www.nature.com/articles/s41598-017-09892-w
15 Hz and at flux densities between 1–4 mT. Each 6 ms burst consisted of a series of 20 consecutive asymmetric pulses of 150 µs on and off duration with an approximate rise time of 17 T/s.
Pulse electromagnetic fields (PEMFs) have been shown to recruit calcium-signaling cascades common to chondrogenesis.
Chondrogenesis is the biological process through which cartilage tissue is formed and developed.
Another proof 17T/s is effective
https://www.sciencedirect.com/science/article/pii/S0142961222002988
17T/s is effective again
https://stemcellres.biomedcentral.com/articles/10.1186/s13287-020-1566-5
We provide evidence that brief exposure to low amplitude PEMFs enhanced the ability of MSCs to produce and secrete paracrine factors capable of promoting cartilage regeneration as well as protecting against adverse inflammatory conditions.
5.3 T/s Worked
https://www.researchgate.net/publication/352001966_Enhancement_of_Nerve_Regeneration_by_Selected_Electromagnetic_Signals
Study showing 2.5 T/s not working
Study showing 1.5 T/s not working
Study showing low slew rate not working
https://www.sciencedirect.com/science/article/abs/pii/S0031938417303876
3mT limit ?
This article makes it look like I should limit the field strength to under 3mt for maximum effectiveness. Have you heard that before?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6902701/
Pulsed therapeutic fields are usually more effective if less than 30 gauss (see Curie's Law and dipole saturation), and frequencies are commonly less than 100 Hz, below which they are referred to as extremely low frequency (ELF). Cell phones are several magnitudes of order larger in both considerations.
**slew rate causes damage
https://ieeexplore.ieee.org/abstract/document/4062729
**Too much slew rate makes permeable
https://www.researchgate.net/figure/The-waveform-of-the-high-dB-dt-magnetic-field-pulse-Each-magnetic-pulse-was-15-s-wide%C2%A7fig1%C2%A7316490221
Too high of a Slew Rate causes potential unhealthy PNS (Peripheral Nerve Stimulation)
https://onlinelibrary.wiley.com/doi/epdf/10.1002/cmr.10011
***Cells Can Die - Killing Yeast Cells***
Inducing 190 V/cm - 19,000 V/m - Muscle Twitch Induced.
Here is another that specifically mentions dB/dT:
https://pubmed.ncbi.nlm.nih.gov/28238117/
Horse continues to twitch after.
NASA Study Showing Squarewave most Biologically Active Waveform
Cell Culture studies: Normal Human Neuronal Progenitor (NHNP) cells were cultured as described in the NASA 2003 paper (3). Briefly, cells were cultured in 100 mm Petri dishes in a temperature, CO2 and humidity controlled cell culture incubator. In initial experiments, not reported in the NASA study, the effects of all 5 waveforms were observed to test the hypothesis that some waveforms would have greater biological effects than others. At that time, detailed gene chip analysis was too costly to perform on every experimental condition, so visual analysis of cell colony formation and density were initially used to rank the effectiveness of each waveform. Both macroscopic and microscopic observations were taken.
https://www.researchgate.net/publication/340330953_Inductively_Coupled_Electrical_Stimulation_-_Part_I_Overview_and_First_Observations
Cell Culture studies: Normal Human Neuronal Progenitor (NHNP) cells were cultured as described in the NASA 2003 paper (3). Briefly, cells were cultured in 100 mm Petri dishes in a temperature, CO2 and humidity controlled cell culture incubator. In initial experiments, not reported in the NASA study, the effects of all 5 waveforms were observed to test the hypothesis that some waveforms would have greater biological effects than others. At that time, detailed gene chip analysis was too costly to perform on every experimental condition, so visual analysis of cell colony formation and density were initially used to rank the effectiveness of each waveform. Both macroscopic and microscopic observations were taken.
https://www.researchgate.net/publication/340330953_Inductively_Coupled_Electrical_Stimulation_-_Part_I_Overview_and_First_Observations
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This one mentions t/s In a few places including a line where it says that 20T/s is the threshold for neuromuscular stimulation
5.3 T/s worked
90 T/s showing a result
2.5 T/s no statisical Significance
1.5 T/s didn't work
Another study showing slew rate is critical
**High slew rate permiability**
Even Dr Pawluk Admits Slew Rate is Important (see video clip below)
Here is clear research showing that the db/dt is directly connected to the induced voltage in your body:
https://www.researchgate.net/figure/Distribution-of-the-induced-electric-field-during-highest-dB-dt-of-the-5-5-coil_fig3_277683544
https://www.researchgate.net/figure/Distribution-of-the-induced-electric-field-during-highest-dB-dt-of-the-5-5-coil_fig3_277683544
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This is one of the reasons I'm leary of kilohertz or megahertz carrier waves for PEMF. Low frequency electrical stimulation of nerves has a regenerative effect, whereas high frequency can make nerve damage worse
13 and 27 Mhz Avoiding Higher Frequency Carrier Waves? This is one of the reasons I'm leary of kilohertz or megahertz carrier waves for PEMF. Low frequency electrical stimulation of nerves has a regenerative effect, whereas high frequency can make nerve damage worse |
It has a power supply that keeps it at full power (still trying to source a variable power supply without dirty output).
At full power the coil gets slightly warm, but if you take measurements with the hall probe or your h field probe I am guessing it will reach farther than anything else you have right now. I did a lot of experimenting to try and find the smallest delta (as opposed to devices that are high intensity at the coil but it drops off really fast in a few inches)
At full power the coil gets slightly warm, but if you take measurements with the hall probe or your h field probe I am guessing it will reach farther than anything else you have right now. I did a lot of experimenting to try and find the smallest delta (as opposed to devices that are high intensity at the coil but it drops off really fast in a few inches)
Sawtooth on magnetic magic
My electric square wave is turned into a magnetic sawtooth because of the inductance of the coil and the configuration of the circuit. The magnetic field rises fast and falls slowly
My electric square wave is turned into a magnetic sawtooth because of the inductance of the coil and the configuration of the circuit. The magnetic field rises fast and falls slowly
Spectral content
After watching the video, it seems pretty clear that they are focused specifically on the results of the fourier transform. There are many ways to get the results to have a similar "spectral content", but the results can easily be manipulated depending on how you set up the parameters of the spectrum analyser.
I would want to see biological evidence in vitro that there enhanced "spectral content" is any better than a high slew rate square wave. If Bob Dennis is correct, there is likely not much difference in how the cells react
imagine that these different balls with different frequencies (the lengths being different and the weights assumed to be the same) represented different molecules resonant frequencies. If you hit them all at once each one will swing at its own resonant frequency. This would correspond to the square wave.
Then imagine that you could push each one at exactly the right time to keep them swinging. This would correspond to a high spectral distribution
Each should have an effect, but it would take some testing to see which is better. I personally like the square wave best still because it just lets everything resonate at it's own frequency naturally instead of forcing it
After watching the video, it seems pretty clear that they are focused specifically on the results of the fourier transform. There are many ways to get the results to have a similar "spectral content", but the results can easily be manipulated depending on how you set up the parameters of the spectrum analyser.
I would want to see biological evidence in vitro that there enhanced "spectral content" is any better than a high slew rate square wave. If Bob Dennis is correct, there is likely not much difference in how the cells react
imagine that these different balls with different frequencies (the lengths being different and the weights assumed to be the same) represented different molecules resonant frequencies. If you hit them all at once each one will swing at its own resonant frequency. This would correspond to the square wave.
Then imagine that you could push each one at exactly the right time to keep them swinging. This would correspond to a high spectral distribution
Each should have an effect, but it would take some testing to see which is better. I personally like the square wave best still because it just lets everything resonate at it's own frequency naturally instead of forcing it
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**To Properly Measure Intensity you need a high speed hall effect sensor**
I purchased 10 high speed hall effect sensors from digikey the other day. If you like I can send one to you. They will make very similar lines on your oscilloscope, but they have the advantage of being able to measure the actual strength of the field. It outputs 65mV per millitesla. It would be great to see a video showing which mat has the most uniform field. Based on my calculations the field is going to be well above the "safe" limits at the surface of the mat if they make 500uT 10" above the mat.
I purchased 10 high speed hall effect sensors from digikey the other day. If you like I can send one to you. They will make very similar lines on your oscilloscope, but they have the advantage of being able to measure the actual strength of the field. It outputs 65mV per millitesla. It would be great to see a video showing which mat has the most uniform field. Based on my calculations the field is going to be well above the "safe" limits at the surface of the mat if they make 500uT 10" above the mat.
Dr Pawluk Uses this Study to Determine how much intensity is needed to create 15 gauss in the body using the inverse square law.
https://www.medicalrent24.it/wp-content/uploads/2018/02/44-Effects-of-electrical-physical-stimuli-on-articular.pdf
Watch starting here:
https://youtu.be/XypkgXgbNAQ?si=SEQLq_jRYberD6si&t=1169
file:///Users/bryantmeyers1/Downloads/I-ONE_therapy_in_patients_undergoing_total_knee_ar%20(1).pdf
https://www.medicalrent24.it/wp-content/uploads/2018/02/44-Effects-of-electrical-physical-stimuli-on-articular.pdf
Watch starting here:
https://youtu.be/XypkgXgbNAQ?si=SEQLq_jRYberD6si&t=1169
file:///Users/bryantmeyers1/Downloads/I-ONE_therapy_in_patients_undergoing_total_knee_ar%20(1).pdf
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Slew Rate
One way of measuring the quality of a sensed signal is to look at the slew rate. The slew rate refers to the slope of the intrinsic signal (Figure 8) and is measured in volts/second.
In electronics, slew rate is defined as the change of voltage or current, or any other electrical quantity, per unit of time. This is similar to Faraday's law as it shows how rapidly a signal rises and falls.
In other cases, a maximum slew rate is specified in order to limit the high frequency content present in the signal, thereby preventing such undesirable effects as ringing or radiated EMI.
One way of measuring the quality of a sensed signal is to look at the slew rate. The slew rate refers to the slope of the intrinsic signal (Figure 8) and is measured in volts/second.
In electronics, slew rate is defined as the change of voltage or current, or any other electrical quantity, per unit of time. This is similar to Faraday's law as it shows how rapidly a signal rises and falls.
In other cases, a maximum slew rate is specified in order to limit the high frequency content present in the signal, thereby preventing such undesirable effects as ringing or radiated EMI.
Biphasic shocks are more effective than monophasic shocks and need lesser energy. Typically when 360 Joules are delivered for defibrillation in a monophasic defibrillator, 200 Joules are given in a biphasic defibrillator.
The proposed mechanism is that a single monophasic wave of energy is not able to depolarize all the myocardial cells. Some cells close to the electrode gets too much energy while those away from the electrode gets too little. Reversing the polarity helps to sweep off these cells as well. This response is sometimes called a ‘burping’ response of a biphasic waveform.
A prospective randomized evaluation compared monophasic and biphasic wave forms in 22 survivors of out of hospital cardiac arrest during implantation of a cardioverter defibrillator [1]. Of the patients, 15 (68%) had lower defibrillation threshold with biphasic pulse.
The proposed mechanism is that a single monophasic wave of energy is not able to depolarize all the myocardial cells. Some cells close to the electrode gets too much energy while those away from the electrode gets too little. Reversing the polarity helps to sweep off these cells as well. This response is sometimes called a ‘burping’ response of a biphasic waveform.
A prospective randomized evaluation compared monophasic and biphasic wave forms in 22 survivors of out of hospital cardiac arrest during implantation of a cardioverter defibrillator [1]. Of the patients, 15 (68%) had lower defibrillation threshold with biphasic pulse.