Electromagnetic Therapy - Page 1
Forum section: electronics / projects

author: Alex_arg
author_rank: Contributor
timestamp: March 26, 2012, 04:54:12 pm
content: Hi all, i like to ask the forum if anyone of you ever build or work with Electromagnetic Therapy equipment?Like those published by several europian electonics magazines in the 90's, in form of kits. (Nuova Elettronica).They assured that is very useful for external treatment of a variety of deseases, and particularly for accelerate broken bones and wounds healing.They work generating a broadband signal up to 300MHz, and applying it in short bursts (100ms) to an "antenna" or radiating element which is applied close to the affected region of the body.I'm building one of these units (to treat my noisy knees), but i can't find some background scientific information to backup the effectiveness of this apparatus, so i decided to post it here like a topic, just in case...I'll aprecciate any information you guys have in this matter.Thank you.PD: My native language is Spanish, so it's possible that my english writing it's not correct.

author: Simon
author_rank: Unknown
timestamp: March 26, 2012, 04:55:35 pm
content: you want to look for a skenar, they are VERY effective and we own 4 in our family (that is over £ 5K total)

author: olsenn
author_rank: Frequent Contributor
timestamp: March 26, 2012, 06:47:35 pm
content: On a slightly related note, I'ce used medical TENS units before but found that they were a novelty item... any perceived therapeutic effect of said device I'd say is probably placebo.

author: Simon
author_rank: Unknown
timestamp: March 26, 2012, 08:24:46 pm
content: Quote from: olsenn on March 26, 2012, 06:47:35 pmA skenar is indeed a form of tens machine but not to be confused with the passive junk out there. It has software that changes the signal based on the bodies reaction and so is very effective. I have witnessed some remarkable recoveries myself. Some placebo effect is probably taking effect, placebo is a side affect of any form of cure and can be a cure in itself

author: Unknown
author_rank: Unknown
timestamp: March 26, 2012, 08:33:21 pm
content: A quick PubMed search found this recent review:Electromagnetic field stimulation for treating delayed union or non-union of long bone fractures in adultsIt refers to and does meta-analysis of four previous studies.At least in the case of fractures, the evidence in favor is not very strong. Based on the current understanding, I see no reason to believe it has any positive effect. The article (full text behind a paywall) also describes several (DC and AC) methods, and claims that although a pulsed field contains a wide spectrum of frequencies, most of the energy is below 1 kHz.

author: Alex_arg
author_rank: Contributor
timestamp: March 27, 2012, 04:11:53 am
content: well, thank you for your comments guys .Simon, look like it work's for you, but i think the scenar uses another type of waves, also they say uses feedback , so maybe got some kind of sensor included to adapt the signal to the body response, this is much sophisticated than the unit i mention (and more expensive). Like most sites in www about this type of apparatus has many words and few figures..Olsenn , that's another issue.. placebo effect, but in the case of TENS, looks like it works at very low frequencies, and the effect it's more anesthetizing than healing.alm i've read that page ,and seems like traditional medicine is biased against alternative therapy, they prefer drugs and surgery , but it's true that no serious study have confirmed the efectiveness of E.M.T. , but what it's interesting to me is that none of the studies i've read prove that these waves could be harmful to the patient, no one.Today i made the PCB for the HF oscillators and i think the unit could be finished in a few days. I tell you what happens then, when i try it :-) Bybe bye and thanks to all.

author: Simon
author_rank: Unknown
timestamp: March 27, 2012, 05:56:30 am
content: Quote from: Alex_arg on March 27, 2012, 04:11:53 amThe skenars feedback is based on the change in skin impedance, this is easily measured by knowing the output voltage and measuring the current going into the body

author: slateraptor
author_rank: Frequent Contributor
timestamp: March 27, 2012, 05:58:31 am
content: Quote from: Alex_arg on March 26, 2012, 04:54:12 pmGood luck trying to find a sound scientific basis. Electromagnetic therapy reeks of pseudo-scientific rubbish.

author: harnon
author_rank: Regular Contributor
timestamp: March 27, 2012, 08:12:48 am
content: Quote from: Alex_arg on March 27, 2012, 04:11:53 amA common misconception. Modern medicine is not against anything, they are FOR scientific method and using statistically proven methods of treatment.

author: Simon
author_rank: Unknown
timestamp: March 27, 2012, 11:34:31 am
content: our NHS (or what is ;left of it) does actually fund weird medicines due to the placebo effect they have. At the end of the day the patient is cured just the same

author: amyk
author_rank: Super Contributor
timestamp: March 27, 2012, 11:37:03 am
content: Quote from: Alex_arg on March 26, 2012, 04:54:12 pmHow much power do they produce? High-power RF does cause tissue heating which has been shown to have biological effects.http://transition.fcc.gov/oet/rfsafety/rf-faqs.html#Q5Quote

author: GrumpyDave
author_rank: Contributor
timestamp: March 27, 2012, 01:52:18 pm
content: Quote from: olsenn on March 26, 2012, 06:47:35 pmOn the contrary, TENS does work and has been proven in clinical trials. However it does not heal, is it used for the relief of pain.Alex_arg, I used to test RF therapy units, although they were not 300Mhz though so perhaps it is not the same as the machine you are building. Years ago these were popular treatments in physiotherapy but the use of them has declined due to unproven results. I will see if i can find a service manual if your interested?

author: Alex_arg
author_rank: Contributor
timestamp: March 27, 2012, 07:13:10 pm
content: thanks Simon, so... skin impedance must change upon application, that would be complicated, umm but maybe a circuit more like an earth resistance meter can do that.... but.... at which fq do you measure skin impedance?? i'll try the original schematic first. then we'll see. Ahh pardon me but what is NHS ??Hi slateraptor , that's what i thought, and why i'm searching this info .Harnon: ok, i understand harnon, but in sake of the scientific spirit, i'm trying to find some answers too.Amyk, i haven't measure yet the output power of this circuit ,but seeing the schematic i say that muchless than a GSM but in a much broader spectrum and below 300MHz (say 200mW max) .i would like to atach the original article ,for you to have more information, but is in Spanish..

author: Unknown
author_rank: Unknown
timestamp: March 27, 2012, 07:26:47 pm
content: Be very careful with applying electrodes directly to the skin. It does not take a lot of voltage to deliver hazardous currents, since electrodes are designed to minimize skin resistance. Regulations for medical equipment like EKG are much more strict than for consumer equipment for a reason.

author: Alex_arg
author_rank: Contributor
timestamp: March 27, 2012, 07:30:40 pm
content: Quote from: alm on March 27, 2012, 07:26:47 pmYes alm, i know , i like to research first..! and as i'd said, i'll try the oscillator alone first, no skin impedance measurig by now. thank you

author: GrumpyDave
author_rank: Contributor
timestamp: March 28, 2012, 09:15:47 am
content: The electrodes from this device are attached to your skin? If so this does sound like a variation of TENS.If it is then alm is right, you must be very carefull. Don't use it on a power supply use a battery!Could you post the schematic?

author: amyk
author_rank: Super Contributor
timestamp: March 28, 2012, 11:49:40 am
content: Agreed with the safety suggestions, since with electrodes on the skin it is essentially administering a controlled electric shock! Measuring the skin impedance seems necessary to prevent too much current going through.

author: Simon
author_rank: Unknown
timestamp: March 28, 2012, 05:04:52 pm
content: never hold the electrodes one in each hand or any other path through the heart. The skenar probes are both on the same "pad"

author: Alex_arg
author_rank: Contributor
timestamp: March 28, 2012, 11:11:49 pm
content: Hi ! , no , no electrodes at all.! it's much like a transmitter with an antenna or radiating element, don't worry i've working with electricity and RF for 30 years..i see if scan or take a pic of the schematic, it's really simple.. a cup of CD4XXX and 4 or 6 lo po transistors, the simplest irradiant is made up with a piece of 60cm of flate wire (like the old IDE hard disk ribbons) grouped in a certain way, to make it ellectrically more longer that the physical 60cm..you never stumble with this project/kit in some electronics magazine in US, UK, AU..? i think it was very popular in mid 90's in Italy and Spain,and have a spanish edition that's sells here down under (but the other side) :-).The only serious electronics magazines that arrives to Argentina were Elektor and Nouva Elettronica ( spanish versions both), and i buy it only when i travel to Buenos Aires. And not mention about components... only the basics ones..the only new components you can buy here is some microcontrollers (mostly Microchip brand), so entusiasts of building stuff ,like me , are confined to old projects like this.Thanks for your comments boys. bye