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Trial registered on ANZCTR


Registration number
Help: Registration number
ACTRN12626001150336
Ethics application status
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Approved
Date submitted
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27/07/2026
Date registered
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16/09/2026
Date last updated
Help: Date last updated
16/09/2026
Date data sharing statement initially provided
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16/09/2026
Type of registration
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Prospectively registered

Titles & IDs
Public title
Adding a synchronised light signal to Transcutaneous Electrical Nerve Stimulation (TENS) for foot and leg pain in adults with diabetes-related nerve damage: a pilot study
Scientific title
Feasibility, tolerability and preliminary effects of Transcutaneous Electrical Nerve Stimulation (TENS) with synchronised visual feedback compared with TENS alone in adults with painful diabetic peripheral neuropathy of the foot and lower leg: a randomised parallel-group pilot trial
Additional trial identifiers [1] 318027 0
Nil
Universal Trial Number (UTN)
Trial acronym
TENS-VF
Related trial records

Health condition
Health condition(s) studied:
Painful diabetic peripheral neuropathy 343031 0
Neuropathic pain of the foot and lower leg 343032 0
Diabetes mellitus (type 1 or type 2) 343033 0
Condition category
Condition code
Neurological 339127 339127 0 0
Other neurological disorders
Metabolic and Endocrine 339128 339128 0 0
Diabetes
Anaesthesiology 339129 339129 0 0
Pain management

Intervention/exposure
Study type
Interventional
Description of the intervention or exposure
Arm 1 (Control): TENS alone
Participants receive transcutaneous electrical nerve stimulation (TENS) delivered using a NeuroTrac® MyoPlus4 Pro Electrical Stimulation and Biofeedback Device (Verity Medical Ltd, United Kingdom), operated in TENS mode with a fixed stimulation protocol.
Materials: the NeuroTrac® MyoPlus4 Pro device, lead wires, and self-adhesive surface electrodes.
Stimulation parameters: biphasic, charge-balanced, rectangular pulses delivered at a fixed frequency of 50 Hz and a fixed pulse width of 350 microseconds. Amplitude is not fixed; it is individually titrated for each participant to a clearly perceptible, comfortable sensory level, below the pain threshold, and the value used is recorded for each participant.
Procedure: participants are seated comfortably with their feet supported. Skin at the electrode sites is inspected and cleaned with an alcohol wipe. Self-adhesive surface electrodes are applied over standardised sites on the dorsal foot and around the ankle, positioned to preferentially activate the peroneal and tibial nerves. Stimulation intensity is increased gradually from zero to a level the participant describes as "strong but comfortable", below the pain threshold, and is not increased further once a stable comfortable level is reached. The selected settings are documented for each participant, and intensity may be reduced at any time at the participant's request.
Dose and schedule: 20 minutes of active stimulation delivered in a single session as two 10-minute blocks separated by a 5-minute seated rest. Additional rest breaks may be requested at any time. The intervention is delivered once only, during a single supervised laboratory visit lasting approximately 2 hours in total.
Mode of delivery: face-to-face, individually administered.
Provider: trained research staff of the study team, under the supervision of the chief investigator, in a university laboratory.
Location: The MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Westmead campus, NSW, Australia.
Tailoring: stimulation amplitude is individually titrated to each participant's sensory threshold as described above. Waveform, frequency and pulse width are fixed and identical across participants and across both arms.
Fidelity: a researcher remains in the room for the entire stimulation period, monitors participant comfort, and records the stimulation settings used, the duration of stimulation actually delivered, any pauses or dose reductions, and any adverse events on the case report form.

Arm 2 (Experimental): TENS plus synchronised visual feedback
Participants receive the identical TENS protocol described for Arm 1, including the same waveform, frequency, pulse width and amplitude titration procedure, with the addition of a synchronised visual feedback accessory.
Materials: as for Arm 1, plus an external, battery-powered LED strip.
Procedure: the LED accessory detects TENS pulses in the lead wires by inductive coupling and, via a microcontroller, triggers brief increases in LED brightness that coincide with each stimulation burst. The accessory does not modify the TENS device or alter the delivered current; it functions solely as a passive detector and visual indicator, and does not contact the participant's body. The LED strip is positioned so that it is easily visible to the participant at the location of the foot, without obstructing movement or causing glare.
Dose, schedule, mode of delivery, provider, location, tailoring and fidelity monitoring are identical to Arm 1.
Intervention code [1] 334901 0
Treatment: Devices
Intervention code [2] 334902 0
Treatment: Other
Description of the comparator or control
The comparator is an active control: transcutaneous electrical nerve stimulation (TENS) alone, delivered using the same NeuroTrac® MyoPlus4 Pro device, the same electrode placement over the dorsal foot and ankle, the same fixed biphasic stimulation parameters, and the same individually titrated "strong but comfortable" intensity as the experimental arm. Participants in the control arm receive 20 minutes of stimulation as two 10-minute blocks separated by a 5-minute seated rest, in a single supervised laboratory session, delivered face-to-face and individually by trained research staff at the same site. The only difference between arms is the absence of the synchronised LED visual feedback accessory.
Control group
Active

Outcomes
Primary outcome [1] 346367 0
Change in neuropathic pain symptom severity, measured as NPSI total intensity score. This is a composite outcome: the total score out of 100 is derived by summing the five NPSI subscores (burning superficial spontaneous pain; pressing deep spontaneous pain; paroxysmal pain; evoked pain; paraesthesia/dysaesthesia). The individual subscores are reported separately as secondary outcomes.
Timepoint [1] 346367 0
Baseline (prior to stimulation, Day 0), immediately after stimulation (Day 0), and 24 hours after the laboratory visit.
Primary outcome [2] 346368 0
Change in self-reported pain intensity across the plantar surface of the feet.
Timepoint [2] 346368 0
Baseline (prior to stimulation, Day 0), immediately after stimulation (Day 0), and 24 hours after the laboratory visit.
Primary outcome [3] 346369 0
Change in self-reported pain distribution across the plantar surface of the feet.
Timepoint [3] 346369 0
Baseline (prior to stimulation, Day 0), immediately after stimulation (Day 0), and 24 hours after the laboratory visit.
Secondary outcome [1] 465534 0
Change in quality of life.
Timepoint [1] 465534 0
Baseline (Day 0) and 24 hours after the laboratory visit.
Secondary outcome [2] 465535 0
Participant-described experience of leg and foot pain. assessed as a composite outcome comprising four domains of a single questionnaire: pain quality; episodic flare-ups; triggers and aggravating factors; and impact on daily life. These domains are analysed together and are not treated as separate outcomes.
Timepoint [2] 465535 0
Baseline (prior to stimulation, Day 0) and 24 hours after the laboratory visit.
Secondary outcome [3] 465537 0
Feasibility of trial delivery, assessed as a composite outcome.
Timepoint [3] 465537 0
Components (i) to (iii) are assessed continuously throughout the recruitment period and summarised at the close of recruitment. Component (iv) is assessed at the end of the Day 0 laboratory visit. Component (v) is assessed at 24 hours after the Day 0 laboratory visit.
Secondary outcome [4] 465538 0
Tolerability and acceptability of the stimulation session, assessed as a composite outcome.
Timepoint [4] 465538 0
Components (i) and (ii) are recorded continuously during the stimulation session on Day 0. Component (iii) is assessed immediately after the stimulation session on Day 0 (primary timepoint) and again at 24 hours after the laboratory visit.
Secondary outcome [5] 465539 0
Incidence and severity of adverse events (Safety).
Timepoint [5] 465539 0
Assessed continuously from the time of consent to the end of the Day 0 laboratory visit, and again at 24 hours after the laboratory visit.
Secondary outcome [6] 467299 0
Change in burning (superficial) spontaneous pain, measured as the corresponding NPSI subscore.
Timepoint [6] 467299 0
Baseline (prior to stimulation, Day 0), immediately after stimulation (Day 0), and 24 hours after the laboratory visit.
Secondary outcome [7] 467300 0
Change in pressing (deep) spontaneous pain, measured as the corresponding NPSI subscore.
Timepoint [7] 467300 0
Baseline (prior to stimulation, Day 0), immediately after stimulation (Day 0), and 24 hours after the laboratory visit.
Secondary outcome [8] 467301 0
Change in paroxysmal pain, measured as the corresponding NPSI subscore.
Timepoint [8] 467301 0
Baseline (prior to stimulation, Day 0), immediately after stimulation (Day 0), and 24 hours after the laboratory visit.
Secondary outcome [9] 467302 0
Change in evoked pain, measured as the corresponding NPSI subscore.
Timepoint [9] 467302 0
Baseline (prior to stimulation, Day 0), immediately after stimulation (Day 0), and 24 hours after the laboratory visit.
Secondary outcome [10] 467303 0
Change in paraesthesia/dysaesthesia, measured as the corresponding NPSI subscore.
Timepoint [10] 467303 0
Baseline (prior to stimulation, Day 0), immediately after stimulation (Day 0), and 24 hours after the laboratory visit.

Eligibility
Key inclusion criteria
Participants must meet all of the following:
- Aged 18 years or older.
- Established clinical diagnosis of type 1 or type 2 diabetes mellitus.
- Pain affecting the foot and/or lower leg (distal to the knee) present for at least 3 months.
- Pain characteristics consistent with painful diabetic peripheral neuropathy on screening, for example burning, stabbing, shooting or electric shock-like pain, tingling, hypersensitivity, or discomfort provoked by normally non-painful stimuli such as socks or bedsheets.
- Clinical signs consistent with painful diabetic peripheral neuropathy, confirmed at the laboratory visit by non-invasive sensory testing, defined as abnormal findings on one or more of: vibration perception testing using a neurothesiometer, 10 g monofilament light touch testing at standard plantar sites, pinprick sensation testing using a Neurotip device.
- Able to attend a single laboratory visit at Western Sydney University and complete a 24-hour telephone follow-up.
- Able to sit comfortably for the duration of the stimulation session.
Sufficient written and spoken English to provide informed consent and complete the study questionnaires.
- Willing to wear surface electrodes on the feet and ankles.
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Healthy volunteers
No
Key exclusion criteria
Participants will be excluded if any of the following apply:
- Presence of an implanted electronic medical device, including cardiac pacemaker, implantable cardioverter-defibrillator, deep brain stimulator or spinal cord stimulator.
- History of epilepsy or a seizure disorder.
- Current pregnancy or breastfeeding.
- Open wounds, ulcers, broken skin, active infection or severe dermatological conditions at or near the planned electrode sites on the feet or ankles.
- Foot or leg pain judged to be primarily attributable to a non-neuropathic cause, such as acute trauma, severe peripheral arterial disease, active infection, or recent surgery.
- Current or recent use of a TENS or other electrical stimulation device for pain management.
- Severe motor impairment limiting safe participation.
- Musculoskeletal conditions that would make seated participation for the duration of the session unsafe or uncomfortable.
- Any other condition that, in the judgement of the investigators, would interfere with safe completion of the study procedures, including severe cognitive impairment.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation is not concealed.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomisation on redcap
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Safety/efficacy
Statistical methods / analysis
G*Power for a two-tailed independent-samples comparison (a = 0.05, power = 0.80) indicated a minimum of 15 participants per group. Allowing for withdrawal, screen failure at the sensory testing stage, and loss to follow-up, a total of 40 participants (20 per group) will be recruited.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
21/09/2026
Actual
Date of last participant enrolment
Anticipated
1/03/2027
Actual
Date of last data collection
Anticipated
2/03/2027
Actual
Sample size
Target
40
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
NSW
Recruitment postcode(s) [1] 46275 0
2145 - Westmead
Recruitment postcode(s) [2] 46276 0
2560 - Campbelltown

Funding & Sponsors
Funding source category [1] 322577 0
Charities/Societies/Foundations
Name [1] 322577 0
Australian Center For Accelerating Diabetes (ACADI)
Country [1] 322577 0
Australia
Funding source category [2] 322578 0
University
Name [2] 322578 0
Western Sydney University
Country [2] 322578 0
Australia
Primary sponsor type
University
Name
Western Sydney University
Address
Country
Australia
Secondary sponsor category [1] 325504 0
None
Name [1] 325504 0
Address [1] 325504 0
Country [1] 325504 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 321052 0
University of Western Sydney Human Research Ethics Committee
Ethics committee address [1] 321052 0
Ethics committee country [1] 321052 0
Australia
Date submitted for ethics approval [1] 321052 0
26/02/2026
Approval date [1] 321052 0
11/05/2026
Ethics approval number [1] 321052 0
H17214

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 152498 0
Prof Paul Breen
Address 152498 0
The MARCS institute for Brain, Behaviour and Development, 160 Hawkesbury Road,, Westmead NSW 2145, Australia
Country 152498 0
Australia
Phone 152498 0
+61 452197751
Fax 152498 0
Email 152498 0
[email protected]
Contact person for public queries
Name 152499 0
Celine Frangieh
Address 152499 0
The MARCS institute for Brain, Behaviour and Development, 160 Hawkesbury Road,, Westmead NSW 2145, Australia
Country 152499 0
Australia
Phone 152499 0
+61 493027686
Fax 152499 0
Email 152499 0
[email protected]
Contact person for scientific queries
Name 152500 0
Paul Breen
Address 152500 0
The MARCS institute for Brain, Behaviour and Development, 160 Hawkesbury Road,, Westmead NSW 2145, Australia
Country 152500 0
Australia
Phone 152500 0
+61 452197751
Fax 152500 0
Email 152500 0
[email protected]

Data sharing statement
Will the study consider sharing individual participant data?
No


What supporting documents are/will be available?

No Supporting Document Provided


Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.