This is a great example of what you can find in the scientific literature, thanks. These kinds of papers are useful, but the real nuggets of information can be tricky to extract.
To begin with, most biomedical scientists do not do a thorough job of calibrating and characterizing their scientific instruments. I know this because I have spent much of my career as a scientific instrument designer, and I have helped dozens of labs correct their experiments and their resulting data by building and characterizing new scientific instruments for them. I have several patents related to this. Getting good biological measurements is very difficult to do, and it is well beyond the knowledge and skill of most biomedical scientists. It is true (but somewhat sad) that even companies that specialize in a particular biomedical instrument do not even fully understand their technology. I have been a consultant for many dozens of biomedical (and other) companies where they hired me to help them figure out how to get their device/product to actually work properly. I have done this over a wide range of technologies, from medical robotics, blood testing devices, physiological instruments, pulmonary and cardiac function, as well as numerous automotive and aerospace technologies. The fact is, many scientists simply do not really know how their devices and instruments really work.
This is a huge problem, and it contributes to what is called the “replicability crisis”, or reproducibility crisis in modern medical research. You can read all about this problem in a recent book titles “Rigor Mortis” by Richard Harris (an NPR reporter). It describes the fact that, when we take the time to check carefully, as much as 75% to 89% of modern biomedical research may be deeply flawed and can not be reproduced because it is basically wrong. I have also been studying this for years and my scientific assessment is that these numbers are actually even worse than reported, but that is the subject of another long and detailed explanation.
For now, let’s start with two basic and critical observations:
1 - Most scientists do not fully understand their scientific instruments, and often they do not fully characterize or calibrate them.
2 - Most scientific papers are wrong, Even if peer-reviewed, the rate of error can be almost 90%. And the problem is that we do not know which 10% is correct. So, you really need to know what you are doing when you read scientific papers, and you also need to look at the results from many papers done independently. A single scientific paper rarely can be relied upon with confidence.
With those observations in mind, let’s take the examples you have presented.
Let’s assume for the moment that they are actually able to get a reproducible effect (doubtful, but let’s assume it for now). Was it due to magnetic intensity, or something else, some other parameter they did not even measure? Let me explain:
They probably did not fully characterize the shape of the magnetic pulse. Very few papers take the trouble to do so. But the pulse shape is important. If the pulsing nature of the waves was unimportant, and the effect were just due to magnetic field strength, then they could just use a solid magnet, no electronics, and they would see the effect. But generally this is not the case. Pulsatile magnetic fields do matter. So the first thing they need to do is clearly describe the pulse. But unfortunately, this is almost never done in a scientific paper.
If they do not know the shape of the pulses, then they can make simple errors. Lets take the simple example of a triangle wave pulse. Lets assume (as is usually the case) that the base of the triangle wave remains constant as they increase the strength (magnetic field strength). So, when they turn up the power, they generate a triangle that is taller, but not wider. If only high-strength fields (tall triangles) have the effect, whereas short triangles (weaker peak magnetic fields) do not, then they conclude that intensity (Gauss) is key.
But this is probably not the case, because the principle electromagnetic effects would arise from dB/dt, the slope of the magnetic wave, not its height. So, as the triangles get taller, the slope gets steeper, and they confuse one (Gauss) with the other (dB/dt). I am pretty sure this is what is happening. I have done many experiments to verify this is often the case.
I could go on writing many more pages about this, but the fact is you would need to know some real math and physics to be able to prove it to yourself.
Another problem is that when they say the magnetic field is a certain Gauss level, they rarely point out exactly how and where this was measured. This is a huge error, because magnetic fields drop off much more quickly that other fields, such as light. You experience this every time you play with magnets: they are only strong when they get very close; otherwise you can hardly feel the attraction or repulsion of magnets. This is because magnetic fields drop off very quickly:
Light drops off as an inverse square: 1/r^2
Magnets drop off as an inverse cube (on axis): 1/r^3, and even more dramatically when you move off the magnetic axis, usually about 1/r^4
Therefore, it is very common to have a high magnetic field in one location, and almost nothing just a centimeter or two further away.
Most people who study and report on the biological effects of pulsed magnetic fields never consider any of the details I have just described above, and there are others to consider as well.
And that is just the problems with the one measurement of the magnetic pulse. There are other problems entirely unrelated to that, such as the high variability of almost all biological measurements. That is another topic.
Keeping all of this in mind, let me try to answer your questions:
Your questions were:
- Can’t scientists conducting these studies test the field strength of the pulse generator using Gaussmeters? And wouldn’t that be standard fare to make sure instruments are correctly calibrated? (My science is pretty weak, so I definitely might be wrong… on a lot of stuff)
- Do you have any studies in which you test weather field strength makes a difference. (I’ve see/heard you talking about studies in which slew rate made a significant difference.)
Answer #1: no, they almost never make this meausrement, and standard Gauss meters can not even measure the slope of a magnetic field, only its peak intensity. I had to build and calibrate my own test meter for this purpose, and we use it to test and calibrate every device we sell. But these devices do not exist commercially, so no PEMF manufacturers and no biomedical scientists use them, unless they build one for themselves.
Answer#2:Yes, I have tested this many, many times, and the answer that I keep finding is: what matters is dB/dt and pulse width. Peak Gauss does not matter directly. It is an indirect consequence of multiplying slope by distance. But waveforms with less slope but equal intensity do not have the same biological effects.
These are very difficult experiments to do and you have to build your own scientific instruments to do them. That is why no one does them.
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