Evaluation of Dual Channel vs. Single Channel FES for Dropfoot
Condition: Dropfoot
Study type: Interventional

Summary: 
      Seventy (70) subjects put on the Ness L300 System, a FES device for ankle dorsiflexion for
      patients with foot drop. Stimulation will be given through two different electrodes: the QFE
      which is a single channel stimulation, and the Segmented Electrode which is a dual channel
      electrode. The purpose of the dual channel stimulation is to enable a balanced dorsiflexion,
      with no inversion/eversion inclinations. Ankle elevation will be recorded both in a seated
      position and during gait. Subject preference will be recorded through BSW Questionnaire and
      Subjective Survey. Twenty first subjects will be stimulated with four different dual channel
      configurations. The configuration that shows to have an advantage over the others will
      continue to be evaluated on fifty additional subjects. Same procedure will be taken place, in
      addition ambulation tests will be performed.
    

Detailed description: 
      Twenty subjects will be stimulated with a single channel electrode, the Quick Fit Electrode.
      The values of stimulation will be recorded, as well as ankle movement (balanced Dorsiflexion,
      inverted or everted Dorsiflexion). Subjects will fill up a Benefit, Satisfaction, Willingness
      to continue (BSW) form. Next, subjects will be fitted with a segmented Electrode that enables
      both single and dual channel. Four configurations of current will be compared during sitting
      position and during gait. The first configuration (A) is segmented electrode single channel
      stimulation, the second configuration (B) is two currents running in parallel. The first
      medial channel stimulates the deep branch of common peroneal nerve (dorsiflexion/inversion)
      and the second lateral current stimulates the superficial peroneal nerve (eversion). In the
      third configuration (C), channels run diagonally. The medial channel runs between the upper
      medial electrode and the lateral lower electrode (dorsiflexion/inversion). The lateral
      channel runs between the lateral upper electrode and the medial lower electrode (eversion).
      The forth configuration (D) includes a common lower electrode; when it is connected to the
      upper medial electrode it functions as a medial channel (dorsiflexion/inversion); when it is
      connected to the upper lateral electrode, it functions as the lateral channel
      (dorsiflexion/eversion). The subjects will be asked to answer 3 questions after trying each
      configuration. 1. Thinking of the current system you use, did this test system provide any
      difference in the way the stimulation feels compared to your existing system? Yes No/Cannot
      tell any difference. 2. Thinking of the current system you use, did this test system provide
      any difference in what you think of as the 'quality' of stimulation you are used to compared
      to your existing system? Yes No/Cannot tell any difference. 3. Thinking of the current system
      you use, did this test system provide any difference in your ability to walk compared to your
      existing system? Yes No/Cannot tell any difference After all three dual channel
      configurations have been tested, subjects will be asked Question 4: Thinking of the last
      three test systems you used today, which test system do you believe was best among the three?
      B, C or D Subjects will be asked to grade their satisfaction with the one dual channel system
      they believe is best using the Benefit, Satisfaction, Willingness to Continue (BSW)
      questionnaire.

      After completing evaluation of the first twenty subjects, a re-evaluation of ten subjects
      will take place. The anode/cathode electrodes will be re-positioned so the cathodes will be
      located at the upper part of the cuff and the anodes will be located at the lower part of the
      cuff. This re-evaluation is needed, since in the first evaluation there was an inconsistency
      in the anode/cathode positioning in the right and left FES cuffs. Stimulation will be given
      while sitting and during 2 minutes walk. Ankle movement and stimulation intensity will be
      recorded and compared to the input received in the initial evaluation of the ten subjects.

      Fifty additional subjects were recruited to evaluate the performence of the common anode
      configuration (configuration D) and compare it to the QFE. configuration D was chosen because
      it showed an advantage over the other dual channel configurations. Same procedure will take
      place in order to compare the performance of the Segmented Electrode (configuration D) and
      the QFE. In addition, ambulation tests will be performed: 2mwt and 10 meter walk test. Gait
      velocity achieved when using each electrode will be compared to each other and also compared
      to gait velocity achieved when walking with no stimulation.
    

Intervention name(s): Functional Electrical Stimulation
Intervention type(s): Device
Intervention description(s): Single channel and dual channel FES for balanced dorsiflexion for patients with dropfoot
Other intervention name(s): Segmented Electrode, Novus System
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Dual Channel Functional Electrical Stimulation; dropfoot, balanced dorsiflexion