A prospective study to determine the safety of the geko®neuromuscular electrostimulation device in a pacemaker population

A prospective study to determine the safety of the geko® neuromuscular electrostimulation device in a pacemaker population | medRxiv /* */ /* */ <!-- <!-- /*! * yepnope1.5.4 * (c) WTFPL, GPLv2 */ (function(a,b,c){function d(a){return"[object Function]"==o.call(a)}function e(a){return"string"==typeof a}function f(){}function g(a){return!a||"loaded"==a||"complete"==a||"uninitialized"==a}function h(){var a=p.shift();q=1,a?a.t?m(function(){("c"==a.t?B.injectCss:B.injectJs)(a.s,0,a.a,a.x,a.e,1)},0):(a(),h()):q=0}function i(a,c,d,e,f,i,j){function k(b){if(!o&&g(l.readyState)&&(u.r=o=1,!q&&h(),l.onload=l.onreadystatechange=null,b)){"img"!=a&&m(function(){t.removeChild(l)},50);for(var d in y[c])y[c].hasOwnProperty(d)&&y[c][d].onload()}}var j=j||B.errorTimeout,l=b.createElement(a),o=0,r=0,u={t:d,s:c,e:f,a:i,x:j};1===y[c]&&(r=1,y[c]=[]),"object"==a?l.data=c:(l.src=c,l.type=a),l.width=l.height="0",l.onerror=l.onload=l.onreadystatechange=function(){k.call(this,r)},p.splice(e,0,u),"img"!=a&&(r||2===y[c]?(t.insertBefore(l,s?null:n),m(k,j)):y[c].push(l))}function j(a,b,c,d,f){return q=0,b=b||"j",e(a)?i("c"==b?v:u,a,b,this.i++,c,d,f):(p.splice(this.i++,0,a),1==p.length&&h()),this}function k(){var a=B;return a.loader={load:j,i:0},a}var l=b.documentElement,m=a.setTimeout,n=b.getElementsByTagName("script")[0],o={}.toString,p=[],q=0,r="MozAppearance"in l.style,s=r&&!!b.createRange().compareNode,t=s?l:n.parentNode,l=a.opera&&"[object Opera]"==o.call(a.opera),l=!!b.attachEvent&&!l,u=r?"object":l?"script":"img",v=l?"script":u,w=Array.isArray||function(a){return"[object Array]"==o.call(a)},x=[],y={},z={timeout:function(a,b){return b.length&&(a.timeout=b[0]),a}},A,B;B=function(a){function b(a){var a=a.split("!"),b=x.length,c=a.pop(),d=a.length,c={url:c,origUrl:c,prefixes:a},e,f,g;for(f=0;f<d;f++)g=a[f].split("="),(e=z[g.shift()])&&(c=e(c,g));for(f=0;f<b;f++)c=x[f](c);return c}function g(a,e,f,g,h){var i=b(a),j=i.autoCallback;i.url.split(".").pop().split("?").shift(),i.bypass||(e&&(e=d(e)?e:e[a]||e[g]||e[a.split("/").pop().split("?")[0]]),i.instead?i.instead(a,e,f,g,h):(y[i.url]?i.noexec=!0:y[i.url]=1,f.load(i.url,i.forceCSS||!i.forceJS&&"css"==i.url.split(".").pop().split("?").shift()?"c":c,i.noexec,i.attrs,i.timeout),(d(e)||d(j))&&f.load(function(){k(),e&&e(i.origUrl,h,g),j&&j(i.origUrl,h,g),y[i.url]=2})))}function h(a,b){function c(a,c){if(a){if(e(a))c||(j=function(){var a=[].slice.call(arguments);k.apply(this,a),l()}),g(a,j,b,0,h);else if(Object(a)===a)for(n in m=function(){var b=0,c;for(c in a)a.hasOwnProperty(c)&&b++;return b}(),a)a.hasOwnProperty(n)&&(!c&&!--m&&(d(j)?j=function(){var a=[].slice.call(arguments);k.apply(this,a),l()}:j[n]=function(a){return function(){var b=[].slice.call(arguments);a&&a.apply(this,b),l()}}(k[n])),g(a[n],j,b,n,h))}else!c&&l()}var h=!!a.test,i=a.load||a.both,j=a.callback||f,k=j,l=a.complete||f,m,n;c(h?a.yep:a.nope,!!i),i&&c(i)}var i,j,l=this.yepnope.loader;if(e(a))g(a,0,l,0);else if(w(a))for(i=0;i (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0];var j=d.createElement(s);var dl=l!='dataLayer'?'&l='+l:'';j.src='//www.googletagmanager.com/gtm.js?id='+i+dl;j.type='text/javascript';j.async=true;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-P4HH5NV'); Skip to main content Home About Submit ALERTS / RSS Search for this keyword Advanced Search A prospective study to determine the safety of the geko ® neuromuscular electrostimulation device in a pacemaker population View ORCID Profile Z. Yousef , C. S. Barr doi: https://doi.org/10.1101/2025.05.20.25327988 Z. Yousef a lead clinician for heart muscle diseases and heart failure devices, University Hospital of Wales , Heath Park, Cardiff. UK CF14 4XW BSc MBBS MD FESC FRCP Roles: Consultant cardiologist Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Z. Yousef For correspondence: marie-therese.targett{at}firstkindmedical.com yousefz{at}cardiff.ac.uk C. S. Barr b Department of Cardiology, Russells Hall Hospital , Dudley, West Midlands, DY1 2HQ MBChB MRCP Roles: Consultant Cardiologist Find this author on Google Scholar Find this author on PubMed Search for this author on this site Abstract Full Text Info/History Metrics Data/Code Preview PDF Abstract There is evidence that some powered muscle stimulators can affect cardiac demand pacemakers, although devices vary enormously in terms of the intensity, frequency, and duration of stimuli. Regulatory authorities require that specialist medical opinion be obtained before using a stimulator on a patient with an implanted device. However, no explicit criteria are specified. This study aims to determine if there are any detectable interactions between a small, wearable stimulator which activates the muscle pumps of the leg by delivering a single momentary pulse at a frequency of 1Hz. 28 patients with pacemakers (single chamber, dual chamber, or bi-ventricular) were given stimulation. The pacemaker marker channel was recorded, and the electrogram examined to detect any sensed signal from the stimulator. In total, 2372 energy pulses were delivered by the stimulators. None of these were sensed by the pacemaker. This appears to show that there is no appreciable interaction between this type of stimulator and cardiac demand pacemakers Introduction Powered muscle stimulators are covered by the United States Food and Drug Administration (FDA) Code of Federal Regulations CFR.890.585 ( 1 ). The code requires that the labelling for powered muscle stimulators includes the contraindication ‘Powered muscle stimulators should not be used on patients with cardiac demand pacemakers’. Further, IEC 60601-2-10:2012 clause 210.7.9.2.101d, requires that the instructions for use provide: “ Advice that a patient with an implanted electronic device (for example a cardiac pacemaker) should not be subjected to stimulation unless specialist medical opinion has first been obtained” . However, the criteria which the specialist should apply are not specified. There is evidence that some powered muscle stimulators, and related devices can affect Cardiac Demand Pacemakers ( 2 , 3 ). However, powered muscle stimulators used to elicit a continuous tetanic contraction of the muscle, for example for functional assistance, typically use sustained pulse trains at a frequency of at least 30Hz ( 4 ) to elicit muscle contractions. The electrodes for these devices may be placed at number of sites on the body depending on the application, including the legs, arms and torso, often with well-spaced electrodes that may be attached to different limbs, sending electrical impulses through the torso. Conversely, a systematic review ( 5 ) of the literature concerning the interaction of physical therapy (including electrical stimulation) and cardiac rhythm devices recognises that the risk of interference from electrical stimulation devices (such as TENS) is lower when the electrodes are placed further away from the cardiac rhythm device and when they operate at low frequencies (2Hz or less). The geko ® range of devices (Firstkind ltd, Daresbury) are small, wearable neuromuscular stimulators which activate the venous muscle pumps of the leg ( 6 , 7 ). They operate by delivering a single momentary (<1 ms) pulse at a frequency of 1Hz with electrodes placed topically, close together, at the knee. The aim of this study was to determine if there are any detectable adverse interactions between the geko ® and pacemakers. The primary endpoint was percentage of pacemaker sensed geko ® pulses in a 30 second period. The secondary endpoints were the incidence of adverse events (AEs), incidence of serious AEs (SAEs), incidence of study treatment related AEs, and the incidence of investigational device related AEs. Materials and Methods 28 informed, consenting patients >18 years with pacemakers were recruited. To minimise risk, only patients who are not pacing dependent were selected for participation. Patients were allocated to one of three study arms based on the type of pacemaker implanted: single chamber, dual chamber, or bi-ventricular. Exclusion criteria were concurrent use of a neuro-modulation device, any medication deemed by the Investigator to interfere with the study treatment (e.g. systemic steroids), and participation in any other clinical study that might interfere. The study had a multi-centre prospective linear design (see Figure 1 ). Download figure Open in new tab Figure 1. Schematic of study design. Consented patients completed an initial baseline study. Here, they rested for a period of 10 minutes, then a sequence of 10 seconds of intrinsic beats were recorded and printed out on the pacemaker programmer using the internal pacemaker intracardiac electrogram (IEG). Following the baseline, a geko ® was fitted to each leg, turned on and run for one minute and a further 10 second intracardiac electrogram recording made with the geko ® devices active. This process was repeated for paced beats without geko ® and finally paced beats with geko ® . Additionally, the pacemaker was placed initially in unipolar sensing mode, then bipolar sensing mode (see Figure 1 ). The geko ® devices were set at the maximum output level tolerated by the patient during the phases of the study where the device was active. A pacemaker programmer was used to program the pacemaker and record the cardiac signal and marker channel. For the purposes of this study geko ® pulses sensed by a pacemaker are defined as ‘Sensed events on the pacemaker programmer marker channel which are not intrinsic cardiac signals and coincide with a geko ® pulse on the surface ECG’ . A paper strip of the simultaneous marker channel, IEG and surface ECG was printed out from the pacemaker programmer for each recording’. It is this printout that was assessed by the investigator to calculate the percentage of sensed geko ® pulses sensed by the pacemaker (primary end point). Results A summary of the patient demographics recorded in the study is detailed in Table 1 . View this table: View inline View popup Download powerpoint Table 1: Patient population demographics Median age of pacemaker in the study was 3.68 years [IQR 1.85-5.94) Four major manufacturers were well represented in the cohort, see figure 2 . Download figure Open in new tab Figure 2. Pacemakers in study, by manufacturer Every subject’s pacemaker performance was assessed by the investigator at baseline to ensure normal function. Test intracardiac electrogram strips were recorded and printed for each patient. These were repeated four times for each subject so that all sensing modalities (unipolar and bipolar) and pacing (paced cardiac rhythm) and non-pacing (intrinsic cardia rhythm) functionality could be assessed. In all cases stable and normal pacemaker function was observed, including lead impedance and pacing/sensing thresholds. In total, 2372 energy pulses were delivered by geko ® devices to patients with implanted on-demand pacemakers. Pulses ranged across the energy output available for the device. Test intracardiac electrogram strips were recorded and printed for each patient. These were repeated four times for each subject so that all sensing modalities (unipolar and bipolar) and pacing (paced cardiac rhythm) and non-pacing (intrinsic cardia rhythm) functionality could be assessed. In all cases, the site investigator assessed the intracardiac pacemaker electrogram to determine if any energy pulses from the geko ® device had been sensed or recorded by the pacemakers; zero (0) geko ® pulses were sensed by pacemakers during this investigation. A summary of the complete data set for all patients, pacemaker types and sensing configurations when the geko ® device is placed and delivering energy pulses to both legs is detailed in Table 2 . View this table: View inline View popup Download powerpoint Table 2: Pacemaker-sensed geko ® pulses for all patients, pacemaker types and sensing configurations. Data from both legs. No adverse events were recorded. Discussion In this study, 2372 energy pulses were delivered by the trial device to 28 patients with variously single chamber, dual chamber, and bi-ventricular pacemakers. Of these 2372 pulses, 0 were detected by the pacemaker’s sensing function. This represents 0% of the sample, with an upper limit for the 95% confidence interval for sensed pulses of 0.25% as calculated by the Clopper-Pearson method ( 8 ). Cardiac demand pacemakers operate by monitoring the P-wave of the heart’s ECG ( 9 ). The P-wave has a typical duration of 0.05 to 0.1s with an interval of about the same to the QRS-wave, the actual contractile pulse. To discriminate between the P-wave and any electromagnetic interference - such as 50-60Hz AC mains supply - cardiac demand pacemakers are fitted with low-pass filters to remove signals of this frequency and higher ( 10 ). The geko ® pulse is a single square wave with a pulse width in the range 50-560µs, which have the same rise/fall dynamics as frequencies in the range 1785-20,000Hz, and thus may be expected to be removed by the pacemaker’s low-pass filter. This concurs with Digby et al ( 5 ) systematic review of the literature concerning the interaction of physical therapy (including electrical stimulation) and cardiac rhythm devices, which ascribed a lower risk of interference from electrical stimulation devices when they operate at low frequencies (2Hz). Badger et al ( 11 ) also conducted a systematic review, which was primarily focussed on Functional Electrical Stimulation (FES) and the potential for interaction with implantable cardioverter defibrillators ICDs). FES devices for drop-foot are similar to the geko ® , in that, they apply electrical stimulation to the common peroneal nerve, albeit at a higher frequency. This group of authors concluded that FES devices for drop-foot could be considered safe when used on patients with pacemakers and ICDs. They also noted that there had been no case studies published concerning electromagnetic interference with pacemakers and ICDs when electrical stimulation was applied to the lower limb. In conclusion, our analysis shows that there is no electro-magnetic interaction between the 1Hz monometric electromagnetic pulse delivered at the tibial site from the geko ® neuromuscular stimulator and a range of cardiac demand pacemakers. The geko ® device therefore appears to be safe to use in patients with implantable pacemakers. Data Availability All data produced in the present study are available upon reasonable request to the authors Footnotes Trial registration: ClinicalTrials.gov Identifier NCT04391257 Ethics: UK NHS REC REF: 20/WA/0166 (IRAS Project ID: 283281) Data sharing statement: Clinical Study Report, Protocol and data will be available on-line at ClinicalTrials.gov following publication. References 1. ↵ Code of Federal Regulations Title 21 , Volume 8 , CFR890.5850 2. ↵ Burri H & Piguet V ‘ UninTENSional pacemaker interactions with transcutaneous electrical nerve stimulation’ Europace ( 2009 ) 11 , 283 – 284 OpenUrl CrossRef PubMed 3. ↵ St Jude Medical Technical Service ‘ Effects of Muscle Stimulators on St . Jude Medical Implantable Cardiac Rhythm Devices ’ 4. ↵ Physical Agents in Rehabilitation 3rd Edition . ED. Cameron MH, Saunders Elsevier . Portland, Oregon 5. ↵ Digby GC , et al. Physiotherapy and cardiac rhythm devices: a review of the current scope of practice Eurospace ( 2009 ) 11 , 850 – 859 OpenUrl CrossRef PubMed 6. ↵ Tucker A , Maass A , Bain D , Chen LH , Azzam M , Dawson H , Johnston A. Augmentation of venous, arterial and microvascular blood supply in the leg by isometric neuromuscular stimulation via the peroneal nerve . Int J Angiol . 2010 Spring ; 19 ( 1 ): e31 – 7 OpenUrl CrossRef PubMed 7. ↵ Jawad H , Bain DS , Dawson H , Crawford K , Johnston A , Tucker A. The effectiveness of a novel neuromuscular electrostimulation method versus intermittent pneumatic compression in enhancing lower limb blood flow . J Vasc Surg Venous Lymphat Disord . 2014 Apr ; 2 ( 2 ): 160 – 5 OpenUrl PubMed 8. ↵ Clopper , C. ; Pearson , E. S. ( 1934 ). “ The use of confidence or fiducial limits illustrated in the case of the binomial ”. Biometrika . 26 ( 4 ): 404 – 413 . OpenUrl CrossRef 9. ↵ Ultra Low-Power Biomedical Signal Processing: An Analog Wavelet Filter … Ch 2 . The evolution of pacemakers: an electronics perspective By Sandro Augusto Pavlik Haddad , Wouter A. Serdijn 10. ↵ Tsibulko VV , Iliev IT , Jekova II Methods for Detecting Pacemaker Pulses in ECG Signal: A Review Annual Journal of Electronics , 2014 11. ↵ Badger J , Taylor P , Swain I The safety of electrical stimulation in patients with pacemakers and implantable cardioinverter defibrillators: A systematic review J . Rehab. & Assist. Tech. Eng . Vol 4 : 1 – 9 2017 OpenUrl View the discussion thread. Back to top Previous Next Posted May 21, 2025. Download PDF Data/Code Email Thank you for your interest in spreading the word about medRxiv. NOTE: Your email address is requested solely to identify you as the sender of this article. Your Email * Your Name * Send To * Enter multiple addresses on separate lines or separate them with commas. You are going to email the following A prospective study to determine the safety of the geko® neuromuscular electrostimulation device in a pacemaker population Message Subject (Your Name) has forwarded a page to you from medRxiv Message Body (Your Name) thought you would like to see this page from the medRxiv website. Your Personal Message CAPTCHA This question is for testing whether or not you are a human visitor and to prevent automated spam submissions. Share A prospective study to determine the safety of the geko ® neuromuscular electrostimulation device in a pacemaker population Z. Yousef , C. S. Barr medRxiv 2025.05.20.25327988; doi: https://doi.org/10.1101/2025.05.20.25327988 Share This Article: Copy Citation Tools A prospective study to determine the safety of the geko ® neuromuscular electrostimulation device in a pacemaker population Z. Yousef , C. S. Barr medRxiv 2025.05.20.25327988; doi: https://doi.org/10.1101/2025.05.20.25327988 Citation Manager Formats BibTeX Bookends EasyBib EndNote (tagged) EndNote 8 (xml) Medlars Mendeley Papers RefWorks Tagged Ref Manager RIS Zotero Tweet Widget Facebook Like Google Plus One Subject Area Cardiovascular Medicine Subject Areas All Articles Addiction Medicine (568) Allergy and Immunology (863) Anesthesia (300) Cardiovascular Medicine (4436) Dentistry and Oral Medicine (444) Dermatology (382) Emergency Medicine (608) Endocrinology (including Diabetes Mellitus and Metabolic Disease) (1509) Epidemiology (15229) Forensic Medicine (30) Gastroenterology (1124) Genetic and Genomic Medicine (6600) Geriatric Medicine (668) Health Economics (997) Health Informatics (4538) Health Policy (1368) Health Systems and Quality Improvement (1613) Hematology (542) HIV/AIDS (1264) Infectious Diseases (except HIV/AIDS) (15916) Intensive Care and Critical Care Medicine (1103) Medical Education (623) Medical Ethics (146) Nephrology (667) Neurology (6599) Nursing (346) Nutrition (998) Obstetrics and Gynecology (1144) Occupational and Environmental Health (957) Oncology (3333) Ophthalmology (974) Orthopedics (369) Otolaryngology (420) Pain Medicine (436) Palliative Medicine (130) Pathology (663) Pediatrics (1693) Pharmacology and Therapeutics (691) Primary Care Research (711) Psychiatry and Clinical Psychology (5447) Public and Global Health (9232) Radiology and Imaging (2198) Rehabilitation Medicine and Physical Therapy (1370) Respiratory Medicine (1196) Rheumatology (593) Sexual and Reproductive Health (712) Sports Medicine (530) Surgery (712) Toxicology (99) Transplantation (289) Urology (265) (function(){function c(){var b=a.contentDocument||a.contentWindow.document;if(b){var d=b.createElement('script');d.innerHTML="window.__CF$cv$params={r:'a00eda675aa10f09',t:'MTc3OTY1MjQ3Ng=='};var a=document.createElement('script');a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElementsByTagName('head')[0].appendChild(a);";b.getElementsByTagName('head')[0].appendChild(d)}}if(document.body){var a=document.createElement('iframe');a.height=1;a.width=1;a.style.position='absolute';a.style.top=0;a.style.left=0;a.style.border='none';a.style.visibility='hidden';document.body.appendChild(a);if('loading'!==document.readyState)c();else if(window.addEventListener)document.addEventListener('DOMContentLoaded',c);else{var e=document.onreadystatechange||function(){};document.onreadystatechange=function(b){e(b);'loading'!==document.readyState&&(document.onreadystatechange=e,c())}}}})();