Effects of electrical stimulation of the calf muscle using a new textile electrode setup on blood flow and discomfort

ISRCTN	ISRCTN49260430
DOI	https://doi.org/10.1186/ISRCTN49260430
Secondary identifying numbers	2019-05479

Submission date: 07/01/2022
Registration date: 11/01/2022
Last edited: 09/05/2023

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Circulatory System

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

Background and study aims
The formation of unwanted blood clots in the veins of the legs is a serious and potentially fatal health problem. Unwanted blood clots in legs can occur as the result of reduced mobility (due to surgery, stroke, injuries, etc), an increased tendency for blood clotting (due to cancer, inherited conditions, etc), and other factors. Neuromuscular electrical stimulation systems (NMES) deliver electrical impulses through electrodes to the skin over muscles to cause muscle contraction. A new textile electrode integrated into socks could give the patient better mobility and better compliance with treatment. The aim of this study is to compare the effects of reusable textile electrodes and traditional NMES-gel electrodes on blood flow and discomfort in healthy volunteers.

Who can participate?
Healthy volunteers aged 18-75 years

What does the study involve?
Participants receive calf electrical stimulation with a set of standard gel electrodes and with a set of textile electrodes integrated into socks. Participants' blood flow will be measured before and during the intervention with an ultrasound of the veins in the knee crease and the groin. Participants will rate their experience of discomfort during the stimulation.

What are the possible benefits and risks of participating?
The short-term NMES treatment tested is not expected to have any benefits or risks for the participants. The participant can withdraw from the study at any time.

Where is the study run from?
Karolinska University Hospital (Sweden)

When is the study starting and how long is it expected to run for?
January 2019 to October 2021

Who is funding the study?
The study is funded by the strategic innovation programs Swelife and Medtech4Health, which are jointly arranged and funded by Sweden´s Innovation Agency (Vinnova), Formas and Energimyndigheten.

Who is the main contact?
Prof. Paul Ackermann
paul.ackermann@ki.se

Contact information

Prof Paul Ackermann
Principal Investigator

Department of Trauma, Acute Surgery and Orthopedics
Karolinska University Hospital
Stockholm
17176
Sweden

ORCID ID	0000-0002-5520-169X
Phone	+46 (0)8 517 700 00
Email	paul.ackermann@ki.se

Study information

Study design	Interventional non-blinded randomized cross over trial
Primary study design	Interventional
Secondary study design	Randomised cross over trial
Study setting(s)	Hospital
Study type	Prevention
Participant information sheet	40909_PIS.pdf
Scientific title	Effects of calf neuromuscular electrical stimulation on hemodynamics and discomfort using a new textile electrode setup
Study objectives	It is hypothesized that a new textile electrode would result in non-inferior hemodynamics and comfort compared to a standard motor point electrode setup of gel electrodes.
Ethics approval(s)	Approved 10/01/2020, Etikprövningsmyndigheten (Box 2110, 750 02 Uppsala, Sweden; +46 (0)10 475 08 00; etikprovning.se), ref: 2019-04020
Health condition(s) or problem(s) studied	Deep vein thrombosis
Intervention	The total time for the intervention including set-up and testing for motor points is 2 hours. Patients are randomized to receive standard treatment or textile electrode treatment first. The wash-out period between the two treatments is 1 week. The intervention is textile electrodes integrated into socks, designated as the transverse textile electrode (TTE) setup, consisting of two rectangular textile electrodes (2 x 2.5 cm) transversally woven into the back of a sock (Polyamide/Lycra blended yarn). The electrodes are placed approximately at the largest circumference of the calf, and with the electrodes inner edges equally distanced from the midline of the calf approximately 2 cm apart. The electrodes are woven into the sock using intarsia knitting which allows for seamless integration of patterns of functional components in a single process. The material of the electrodes is silver coated polyamide multifilament yarn with the trade name Shieldex® (produced by Statex Produktions und Vertriebs GmbH). The intervention is compared to commercially available standard adhesive gel electrodes (Compex Snap, Performance, DJO Global, USA, 5 x 5 cm) manually trimmed to squares sized 3 x 3 cm to reduce the current intensity needed to induce a muscle response. The standard electrodes are placed on the skin areas of the calf, one on the medial side and one on the lateral side, that required the least NMES current intensity to trigger a calf muscle response, i.e. the “best” motor points (MP). This electrode setup is designated the motor point electrode (MPE) setup.
Intervention type	Device
Pharmaceutical study type(s)
Phase	Phase I
Drug / device / biological / vaccine name(s)	Shieldex®
Primary outcome measure	Peak venous velocity in vena poplitea measured using Doppler ultrasound (CX50, Philips Medical Systems, Andover, MA, USA) during baseline and on three occasions during a 5-minute neuromuscular electrical stimulation of the calf
Secondary outcome measures	Peak venous velocity in vena femoralis measured using Doppler ultrasound (CX50, Philips Medical Systems, Andover, MA, USA) during baseline and on three occasions during a 5-minute neuromuscular electrical stimulation of the calf
Overall study start date	01/01/2019
Completion date	10/10/2021

Eligibility

Participant type(s)	Healthy volunteer
Age group	Mixed
Lower age limit	18 Years
Upper age limit	75 Years
Sex	Both
Target number of participants	10
Total final enrolment	10
Key inclusion criteria	Healthy volunteers aged 18-75 years
Key exclusion criteria	1. Pregnancy 2. Skin ulcers 3. Previous surgery on blood vessels of the lower limbs 4. Pacemaker 5. Intracardiac defibrillator 6. Advanced heart disease 7. Kidney failure 8. Neuromuscular or metabolic disease
Date of first enrolment	10/01/2020
Date of final enrolment	20/01/2021

Locations

Countries of recruitment

Sweden

Study participating centre

Karolinska University Hospital

Akademiska Stråket 13
Solna
17164
Sweden

Sponsor information

Karolinska University Hospital
Government

Eugeniavägen 3, Solna
Stockholm
17176
Sweden

Phone	+46 (0)8 517 70 000
Email	info.karolinska@sll.se
Website	https://www.karolinska.se/en/karolinska-university-hospital/about-karolinska/contact-and-visit-us/
"ROR"	https://ror.org/00m8d6786

Funders

Funder type

Government

VINNOVA
Government organisation / National government

Alternative name(s): Swedish Governmental Agency for Innovation Systems
Location: Sweden

Svenska Forskningsrådet Formas
Government organisation / National government

Alternative name(s): Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning, Swedish Research Council Formas, Formas
Location: Sweden

Energimyndigheten
Government organisation / National government

Alternative name(s): Swedish Energy Agency, egentligen Statens energimyndighet, STEM
Location: Sweden

Results and Publications

Intention to publish date	10/04/2022
Individual participant data (IPD) Intention to share	Yes
IPD sharing plan summary	Available on request
Publication and dissemination plan	The results are planned for publication in a high-impact peer-reviewed journal.
IPD sharing plan	Raw data will be available from the researchers on reasonable request. What data will be shared: All the individual participant data collected during the trial, after deidentification. What other documents: Patient information, study protocol. When: Immediately following publication and ending 5 years following publication. With whom: Researchers who provide a methodologically sound proposal. For what: To achieve the aims in the approved proposal. By what mechanisms: Proposals should be directed to Robin Juthberg (robin.juthberg@ki.se). Requestors will need to sign a data access agreement.

Study outputs

Output type	Date created	Date added	Peer reviewed?	Patient-facing?
Participant information sheet		11/01/2022	No	Yes
Protocol file		11/01/2022	No	No
Preprint results	18/01/2022	20/12/2022	No	No
Results article	05/05/2023	09/05/2023	Yes	No

Additional files

40909_PIS.pdf
40909_PROTOCOL.pdf

Editorial Notes

09/05/2023: Publication reference added.
20/12/2022: Preprint reference added.
17/02/2022: The intention to publish date has been changed from 10/02/2022 to 10/04/2022.
11/01/2022: Trial's existence confirmed by Etikprövningsmyndigheten (The Ethics Review Authority).