TENS and EMS

by Master Bob

Over the counter TENS and EMS units are similar to the machines that doctors and physiotherapists use, they are not identical. A doctors prescription is usually required to purchase an 'industrial strength" TENS machine, and most consumer non-prescription products are marketed as muscle toners or exercise machines.

In 1965 Drs. Ronald Melzack of Canada and Patrick Wall of the U.K. published a paper explaining a new comprehensive theory, known as the Gate Control Theory, of how pain is processed by our nervous systems. This theory also explained how electrical stimulation can influence the physiology of pain. By 1967 electrical devices were surgically implanted to control severe low back pain. Shortly thereafter, surface electrical units were used to test the person's response as a means of screening suitable surgical candidates. It was soon discovered that these surface electrical stimulators were also effective and they could be used for the relief of pain without the surgery. Since then, these devices, known as Transcutaneous Electrical Nerve Stimulators (TENS), have become widely accepted by physicians to control most forms of pain.

They have also found their way into the toy boxes of kinksters..

The best way to determine if you want a TENS or EMS machine is to talk to people that have one, ask them questions about the use of the machines, and try them yourself or on your partner. The signals generated by TENS and EMS devices vary by unit and manufacturer, so it is essential to do some research and read the product specifications before you purchase a machine. Although EMS and TENS machines can be used to inflict pain, a little bit of knowledge never hurts...

There are two basic types of readily available consumer market electronic stimulators machines: TENS, and EMS.

TENS is designed to help relieve certain types of chronic and acute pain, and is more suited for nerve related pain conditions, while an EMS is designed to treat more of the muscle area than the nerves. EMS differs from TENS in that it is designed to stimulate muscle motor nerves, while TENS is designed to stimulate sensory nerve endings to help decrease pain. Many TENS units operate as both EMS and TENS in several modes.

Electronic Muscle Stimulation ( EMS), also known as Neuromuscular Stimulation Therapy (NMS) and Electrosic Muscle Exercise (EME), is electrical muscle stimulation using electrical pulses to stimulate nerve axons, sending signals to your muscle to expand and contract. This type of stimulation is characterized by a low voltage Mono-Phasic stimulation targeted to stimulate motor nerves to cause a muscle contraction.

A Typical EMS Unit

Pulse amplitude: Adjustable 0 to 80 mA each channel.

Relaxation period: Variable 1-30 seconds

Pulse ramp: 1,3,5 seconds

Pulse frequency: 5, 30, 100 Hz

Contraction period: 1-30 seconds

TENS, Transcutaneous Electrical Neural Stimulation:

TENS stimulates sensory nerves to block pain signals, stimulate endorphin production to help normalize sympathetic function. TENS also encourages the body to produce higher levels of its own natural pain killing chemicals called Endorphins and Encephalins.

TENS is characterized by the use of biphasic current and selectable parameters such as pulse rate and pulse width. In principle, TENS applies an electrical force that stimulates pain-suppressing A-beta afferent nerve fibers which compete against pain-carrying afferent nerve fibers.

Common characteristics include high frequency stimulation patterns of individual

TENS is characterized by biphasic pulses where the positive phase of each pulse is typically a square-wave while the negative phase is a sawtooth-ramp waveform. The positive/negative phases may be asymmetric about zero voltage (to minimize DC effects to the skin and subcutaneous metabolites). The duration of the individual pulses typically range from 30 to 250 microseconds. Pulse rate typically varies from 3 to 1000 Hz. TENS units generally fall into one of three categories; traditional TENS, burst TENS, or modulated TENS. Burst TENS units output bursts of pulses – for example a repeating pattern of 8 pulses per burst with 12 bursts per second. Modulated TENS outputs variable burst patterns, and of variable intensity. In summary, there is no single burst pattern considered to be TENS exclusively, rather the pulse itself seems to characterize TENS. 1

A Typical TENS Unit

Channels Dual, isolated between channels

Pulse amplitude: Adjustable 0 - 80 mA

Pulse rate: Adjustable 2 to 150 Hz

Pulse width: Adjustable 60 to 250 microseconds

Pulse Width 60 to 250 microseconds, adjustable

When shopping for a TENS unit, a good general rule of thumb is the more controls and the more parameters that you can adjust or select, the better ( also equals spending more money). A few of the important features are listed here.

Many TENS units operate as both EMS and TENS in several modes; Burst, Modulated and Continuous.

Normal Mode

Normal Mode is the conventional TENS mode and will produce a gentle and pleasant 'tingling' under and between the two electrodes. The Pulse Rate and Pulse Duration controls work independently according to the settings chosen. Also referred to as Conventional Mode, or Continuous Mode.

Burst Mode

In Burst Mode, the instrument will deliver a group or burst of individual pulses. Burst mode produces a rhythmic pulse which should be strong enough to produce a twitch in the muscles underneath the electrodes. This muscle twitch helps to release endorphins.

Modulated TENS Mode.

Modulation Mode is designed to prevent nerve accommodation. The Pulse Rate will start at approximately 100 pulses per second, gradually change frequency to approximately 50 p.p.s. and then return back to 100 p.p.s. The cycle occurs approximately every four seconds. This mode produces a gentle and comforting massage effect which exercises problematic muscles and helps to reduce musculoskeletal pain.

Pulse Duration Control - Pulse Width

The duration of the electrical waveform pulse (also known as Pulse Width). The range possible is 50 to 250 microseconds. Changing the pulse duration will provide a different feel or texture to the electrical current. This is because different types of nerve fibers will respond differently to a particular pulse duration. The longer the pulse, the more total energy each individual pulse generates, allowing the pulse to spread the current over greater distances. The maximum parameters in most TENS units ranges from 50 to 400 microseconds. The further apart the electrodes are, the wider the pulse width should be.

Pulse Rate Control - Repetition Rate

At the lower frequencies (below 30 - 40 pulses per second) you may be able to feel the individual pulses and a tapping sensation will result. Above that rate, your body is not able to differentiate each individual pulse and a buzzing sensation will be perceived.

As with the Pulse Duration Control, if you increase the pulse frequency, you are increasing the amount of energy being delivered to the body. You will then need to adjust the Intensity Controls. Always turn any dial slowly so that you don't surprise yourself.

Not for therapeutic use....The ultimate electrical toy for computer geeks.

Unlike handheld TENS and EMS units that are designed for pain relief and muscle toning, the Erostek ET-312 is designed as a BDSM electro-play toy. Medical devices were not designed to be erotic, and this product was not designed to treat medical conditions...

It has 18 built in modes and you can program it with your computer, download more functions from the Internet and easily link two units together. Other features include a high frequency output tri-phase stimulation output that creates a third stimulus waveform between channels A and B, and a stereo audio input. You can use the included external microphone, or connect the ET-312 to the audio output on your computer or MP3 player - wave files are transformed into much low duty cycle TENS-style waveforms that maintain the frequency, amplitude and phase characteristics of the music. Nasty.

According to the manufacturer " Most of our customers never use the full output of our products. For that reason, we've added a new Low Power setting that limits the maximum intensity. This makes adjustments easier and safer. For those few hardcore folks for whom too much is never enough, we've added a new High Power setting that manages to exceed what even our previous models can deliver. "

Note that there are two versions; ET-312 for North American markets, and the ET-312BE, a 220 volt model for use in Europe.

A slightly more affordable pervertible

The Conair Body Tone model 8310C is marketed as an Electrostimulation device that can be used to "shape, tone and relax your body". What it is not marketed as is more interesting...

This non-prescription six channel unit packs a pretty good wallop, comes complete with an AC adapter, 12 electrode pads, a handy waist belt, and all the wires you need to connect your victim to the machine and zap them in 6 spots at once.

Typical of an on the shelf unit, the controls are limited; you can independently adjust the voltage on each output channel, and the time period between the cycles of the three pre-programmed modes. The toning mode can make muscles spasm quite nicely, and the massage mode delivers a rather nasty set of electronic pinpricks. All in all, a nice little machine.

Accessories mild and wild

You can purchase a wide variety of rather interesting and versatile accessories for TENS units, including the Electro Gloves shown to left.

Accessories fall into two general categories; single lead toys that need to be used with another single lead toy to complete a circuit, such as the gloves to the left, and, bi-polar toys that can be used on their own, such as the cock cage below.

There are also external accessories such as a cock harness, scrotum parachute, ball stretcher, penis strap, penis pads, electro rings, leather g-string, ear clips, and breast cups. More info? Try here.

If that's not enough, you can purchase internal accessories including an anal dildo, vaginal probe and dildo, panty with solid chome egg, and a hegar sound. More info? Try here.

If you're really sick, you could just use the conductive pads that come with the unit or make your own...

Safety Warnings

Depending on the number of output channels, either 2 or 4 electrodes are applied to the skin, which allow electrical pulses generated in the TENS unit to be transmitted to the nerves which lie underneath the skin surface. Most TENS units work with biphasic currents in the milliamp range delivered for about 250 microseconds. The low-volt electrical current delivered by the electrodes only penetrates the skin to the level of the nerve fibers, usually only one to two inches. This poses no danger to most individuals. However, those with cardiac conditions and/or pacemakers, and pregnant women should consult their doctors before using TENS. Also, neck and head pain that requires locating electrodes on these areas of the body should be conducted only with the consent of a physician.

Be sure to read, understand, and follow all instructions and safety warnings that come with your TENS or EMS unit.

Further Reading About TENS and EMS
An Easy Guide to TENS Pain Relief Dr. G. Gadsby		An Easy Guide to EMS Dr. G. Gadsby

1. Description and comparison of traditional T.E.N.S. Stuart M. McGill, PhD Professor of Spine Biomechanics, University of Waterloo, Canada, June 2002

Master Bob.net Knowledge Base - TENS And EMS