Relief at the source of pain, plus muscle rehabilitation

RS-4i® Plus Sequential Stimulator with Intersperse®

The RS-4i Plus Sequential Stimulator uniquely combines true high frequency (5000 Hz) Interferential therapy for long-lasting pain relief, with neuromuscular electrical stimulation (NMES) for muscle rehabilitation. During the same, uninterrupted treatment session, the RS-4i Plus both excites the body’s natural endorphin production to relieve pain, and provides rehabilitative muscle therapy that reduces muscle spasms, increases circulation, and prevents disuse atrophy.

Use one of 78 pre-programmed treatments, or save a customized treatment regimen to meet specific needs. Don’t worry. The last treatment you used is saved as your default. There’s no need to hunt for preferred therapies.

RS-4i Plus treatments begin with a few minutes of Interferential therapy, in which the RS-4i Plus blocks the transmission of pain signals to the brain with a high-frequency waveform that penetrates deep into tissue. Pain Relief treatment segments can help relieve acute musculoskeletal pain or relieve and manage chronic musculoskeletal pain.

After Interferential therapy knocks down the pain, the RS-4i Plus effortlessly shifts to NMES for the second treatment segment. During muscle therapy, the RS-4i Plus delivers a custom waveform that causes the treated muscle to involuntarily contract, relaxing muscle spasms, preventing or slowing muscle atrophy, increasing circulation and maintaining or increasing range of motion.

As the patient sits undisturbed, the third and most unique segment begins. It consists of Intersperse®, which combines Interferential pain relief and rehabilitative muscle stimulation in a single treatment. With Intersperse, during the relax period of muscle stimulation, pain relief signals are delivered. You’re knocking down the pain, then working the muscle in a repeating pattern.


Reach pain at its source

  • True high frequency (5000 Hz) stimulation to reach deep into soft tissue

  • Interferential therapy reduces pain at the source and excites the body’s natural pain reducing mechanisms

  • NMES provides deep muscle stimulation that reduces spasms and increases circulation to aid in mobility and healing

  • Premodulation of the Interferential signals allows seamless transition between Interferential therapy and NMES in a single treatment—without repositioning electrodes

Benefit from ease of use plus versatility

  • At home, self-managed treatment

  • Individual electrodes treat any areas of skeletal muscle, while wearables properly target common areas of pain in the low, mid and upper back

  • One-on-one guidance on proper use

  • Easily selectable from pre-set programs, yet highly customizable

Indications for use

  • Relieve acute pain

  • Relieve and manage chronic pain

  • Reduce muscle spasm

  • Maintain or increase range of motion

  • Re-educate muscle

  • Reduce muscle atrophy   

  • Increase blood circulation

  • Prevent venous thrombosis

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