Electrocardiographic Electrodes Research Articles

Development of a Wearable Cardiac Monitoring System for Behavioral Neurocardiac Training: A Usability Study.

BackgroundElevated blood pressure is one of the main risk factors for death globally. Behavioral neurocardiac training (BNT) is a complementary approach to blood pressure and stress management that is intended to exercise the autonomic reflexes, improve stress recovery, and lower blood pressure. BNT involves cognitive-behavioral therapy with a paced breathing technique and heart rate variability biofeedback. BNT is limited to in-clinic delivery and faces an accessibility barrier because of the need for clinical oversight and the use of complex monitoring tools.ObjectiveThe objective of this project was to design, develop, and evaluate a wearable electrocardiographic (ECG) sensor system for the delivery of BNT in a home setting.MethodsThe wearable sensor system, Beat, consists of an ECG sensor and a mobile app. It was developed iteratively using the principles of test-driven Agile development and user-centered design. A usability study was conducted at Toronto General Hospital to evaluate feasibility and user experience and identify areas of improvement.ResultsThe Beatsensor was designed as a modular patch to be worn on the user’s chest and uses standard ECG electrodes. It streams a single-lead ECG wirelessly to a mobile phone using Bluetooth Low Energy. The use of small, low-power electronics, a low device profile, and a tapered enclosure allowed for a device that can be unobtrusively worn under clothing. The sensor was designed to operate with a mobile app that guides users through the BNT exercises to train them to a slow-paced breathing technique for stress recovery. The BNT app uses the ECG captured by the sensor to provide heart rate variability biofeedback in the form of a real-time heart rate waveform to complement and reinforce the impact of the training. Usability testing (n=6) indicated that the overall response to the design and user experience of the system was perceived positively. All participants indicated that the system had a positive effect on stress management and that they would use it at home. Areas of improvement were identified, which focused primarily on the delivery of training and education on BNT through the app.ConclusionsThe outcome of this project was a wearable sensor system to deliver BNT at home. The system has the potential to offer a complementary approach to blood pressure and stress management at home and reduce current accessibility barriers.

Functional Nanomaterials: Energy and Sensing

Sponsored by the Nanomaterials Committee, this special topic has a unique combination of short review papers and research papers on some recent advances for using functional nanomaterials for energy conversion/storage and optical/electric/magnetic signal sensing. The invited paper from Zhu’s group is an extension of their talk ‘‘One-Dimensional Nanostructures for Wearable Devices’’ presented at the TMS 2015 Annual Meeting & Exhibition (TMS2015). The paper reviews nanomaterial-enabled dry electrodes for electrophysiological sensing, particularly on electrocardiography (ECG). It starts with an overview of two different commercial electrodes (i.e., pre-gelled wet electrode and dry electrode), their electrode–skin interface models and the source of noise. The overview shows that dry electrodes have certain advantages over the wet ones, such as the elimination of signal degradation caused by dehydration of the gel. The overview also points out that (1) flexible dry electrodes are needed to form intimate contact with skin surface so that the movement of electrodes and motion artifacts can be suppressed and reduced, and (2) the nanomaterials-based electrode could be the solution. The paper then presents a comprehensive review on recent developments of dry ECG electrodes made of various nanomaterials, including metallic nanowires, metallic nanoparticles, carbon nanotubes and graphene. Their fabrication processes and performances are discussed. The paper concludes that nanomaterials-enabled dry ECG electrodes are attractive candidates for long-term ECG sensing, and calls for more studies in this field. The invited paper from Zhao’s team is a recap of their talk ‘‘Detecting Bacteria by Surface Enhanced Raman Spectroscopy’’ at TMS2015. This paper reports how surface-enhanced Raman spectroscopy (SERS) contributes to food safety by detecting the low levels of pathogenic microorganisms that may exist in foods. In particular, vegetables and fruits are vulnerable to contamination by pathogenic microorganisms since they are natural vehicles of pathogens from cultivation to delivery. Therefore, to detect a small amount of harmful microorganisms is a very important, but challenging task for food safety. Compared with traditional Raman spectroscopy, SERS exploits novel metal nanostructures to enhance the sensitivity. In this study, the authors demonstrate that the limit of detection (LOD) of Salmonella Poona from cantaloupe cubes can be as low as 100 CFU/ml in less than 4 h by performing SERS measurements on vancomycin-coated silver nanorod (VAN AgNR) substrates. It is claimed that such a small LOD has not previously been reported for label-free, intrinsic SERS detection using real food samples. This result suggests that the SERS detection technique based on AgNR is a powerful platform for a rapid, simple, and inexpensive means of pathogenic bacteria detection, which will be very useful in securing the safety of fresh foods.

Nanomaterial-Enabled Dry Electrodes for Electrophysiological Sensing: A Review

Long-term, continuous, and unsupervised tracking of physiological data is becoming increasingly attractive for health/wellness monitoring and ailment treatment. Nanomaterials have recently attracted extensive attention as building blocks for flexible/stretchable conductors and are thus promising candidates for electrophysiological electrodes. Here we provide a review on nanomaterial-enabled dry electrodes for electrophysiological sensing, focusing on electrocardiography (ECG). The dry electrodes can be classified into contact surface electrodes, contact-penetrating electrodes, and noncontact capacitive electrodes. Different types of electrodes including their corresponding equivalent electrode–skin interface models and the sources of the noise are first introduced, followed by a review on recent developments of dry ECG electrodes based on various nanomaterials, including metallic nanowires, metallic nanoparticles, carbon nanotubes, and graphene. Their fabrication processes and performances in terms of electrode–skin impedance, signal-to-noise ratio, resistance to motion artifacts, skin compatibility, and long-term stability are discussed.

Apical Hypertrophic Cardiomyopathy.

To the Editor We have read with interest the excellent review on hypertrophic cardiomyopathy (HCM)1 and wish to comment on the apical variant of the disease listed in Table 4 but not discussed in the text. This variant can be found in 15% to 25% of Chinese and Japanese cohorts with HCM but only in 3% of American cohorts.2 The typical electrocardiography (ECG) shows the loss of septal Q waves, high QRS voltage, and repolarization abnormalities with deep T-wave inversion, especially in the leads closest to the apex—V4–V6.2 Because hypertrophy is confined to the apex, dynamic left ventricular outflow tract obstruction and systolic anterior motion of the anterior mitral valve leaflet are absent. The apical pulse may be sustained on palpation, and an S4 heart sound may be heard.2 There may not be a systolic murmur. It is reasonable to expect some degree of diastolic dysfunction and the possibility of relative apical ischemia as a result of the unbalanced wall thickness-to-vascular supply ratio.3 HCM apical variant may not have a totally benign prognosis with atrial fibrillation and myocardial infarction occurring in up to one-third of patients during long-term follow-up in the Western population.3,4 In addition, in patients with atrial fibrillation, HCM (including the apical variant) may increase the risks of systemic thromboembolism and the need for long-term anticoagulation.5,6 However, there are currently no data to suggest that the perioperative risks are increased in afflicted patients without a history of syncope, chest pain, dyspnea, or heart failure. Nonetheless, in a young asymptomatic patient, the bizarre ECG pattern first seen when intraoperative ECG electrodes are placed can be alarming and may even lead to the postponement of surgery or initiation of coronary vasodilator treatment. Alternatively, a preoperative ECG may lead one to suspect HCM. However, plain echocardiography may still miss apical HCM if the apex is not adequately examined.3 A microbubble contrast-enhanced echocardiography or cardiac magnetic resonance imaging, or both, may be required to differentially diagnose apical HCM, coronary artery disease, myocardial tumor, ventricular aneurysm, ventricular noncompaction, or endomyocardial fibrosis.3 Anthony M. H. Ho, MD, FRCPC, FCCP Department of Anesthesiology and Perioperative Medicine Queen’s University and Kingston General Hospital Kingston, Ontario, Canada [email protected] Po T. Chui, MBBS, FANZCA Alex P. W. Lee, MBChB, MRCP Song Wan, PhD, MD, FRCS Departments of Anaesthesia and Intensive Care, Medicine & Therapeutics, and Surgery The Chinese University of Hong Kong and Prince of Wales Hospital Hong Kong SAR, People’s Republic of China

A novel method of fabricating carbon nanotubes-polydimethylsiloxane composite electrodes for electrocardiography

Polymer-based flexible electrodes are receiving much attention in medical applications due to their good wearing comfort. The current fabrication methods of such electrodes are not widely applied. In this study, polydimethylsiloxane (PDMS) and conductive additives of carbon nanotubes (CNTs) were employed to fabricate composite electrodes for electrocardiography (ECG). A three-step dispersion process consisting of ultrasonication, stirring, and in situ polymerization was developed to yield homogenous CNTs–PDMS mixtures. The CNTs–PDMS mixtures were used to fabricate CNTs–PDMS composite electrodes by replica technology. The influence of ultrasonication time and CNT concentration on polymer electrode performance was evaluated by impedance and ECG measurements. The signal amplitude of the electrodes prepared using an ultrasonication time of 12 h and CNT content of 5 wt% was comparable to that of commercial Ag/AgCl electrodes. The polymer electrodes were easily fabricated by conventional manufacturing techniques, indicating a potential advantage of reduced cost for mass production.

Right Parasternal Electrode Configuration Converts a Failed Electrocardiographic Screening to a Pass for Subcutaneous Implantable Cardioverter-Defibrillator Implantation

Pre-operative electrocardiographic (ECG) screening before subcutaneous implantable cardioverter-defibrillator (SICD) implantation is essential to prevent T-wave oversensing and inappropriate shocks. The failure rate of ECG screening was reported to be up to 8% when only two body positions were tested. Three subcutaneous ECG vectors represented by lead I, II and III were obtained in standing, supine, sitting and squatting positions. A patient qualified if the ECG in any same lead passed in all four positions. We report a 31-year-old man with idiopathic ventricular fibrillation who failed ECG screening for SICD implantation with the conventional left parasternal electrode (LPS) configuration in all three subcutaneous ECG vectors. Right parasternal electrode (RPS) configuration with left arm and right arm ECG electrodes positioned 1cm lateral to right sternal border was attempted for screening. The amplitude of the QRS complex was significantly larger in the RPS compared to the LPS configuration in lead III and the patient passed the ECG screening in four body positions. He underwent successful SICD implantation with RPS approach with appropriate sensing both during the procedure and exercise treadmill test four weeks later. Ventricular fibrillation was successfully converted with 65J standard polarity shock during the procedure and no ICD shock was experienced by the patient on six-month follow-up. RPS configuration may be considered in patients who fail the ECG screening with the conventional LPS approach for SICD implantation.

A Study on the Optimal Positions of ECG Electrodes in a Garment for the Design of ECG-Monitoring Clothing for Male.

Smart clothing is a sort of wearable device used for ubiquitous health monitoring. It provides comfort and efficiency in vital sign measurements and has been studied and developed in various types of monitoring platforms such as T-shirt and sports bra. However, despite these previous approaches, smart clothing for electrocardiography (ECG) monitoring has encountered a serious shortcoming relevant to motion artifacts caused by wearer movement. In effect, motion artifacts are one of the major problems in practical implementation of most wearable health-monitoring devices. In the ECG measurements collected by a garment, motion artifacts are usually caused by improper location of the electrode, leading to lack of contact between the electrode and skin with body motion. The aim of this study was to suggest a design for ECG-monitoring clothing contributing to reduction of motion artifacts. Based on the clothing science theory, it was assumed in this study that the stability of the electrode in a dynamic state differed depending on the electrode location in an ECG-monitoring garment. Founded on this assumption, effects of 56 electrode positions were determined by sectioning the surface of the garment into grids with 6cm intervals in the front and back of the bodice. In order to determine the optimal locations of the ECG electrodes from the 56 positions, ECG measurements were collected from 10 participants at every electrode position in the garment while the wearer was in motion. The electrode locations indicating both an ECG measurement rate higher than 80.0% and a large amplitude during motion were selected as the optimal electrode locations. The results of this analysis show four electrode locations with consistently higher ECG measurement rates and larger amplitudes amongst the 56 locations. These four locations were abstracted to be least affected by wearer movement in this research. Based on this result, a design of the garment-formed ECG monitoring platform reflecting the optimal positions of the electrode was suggested.

Stop the Noise: A Quality Improvement Project to Decrease Electrocardiographic Nuisance Alarms.

As many as 99% of alarm signals may not need any intervention and can result in patients' deaths. Alarm management is now a Joint Commission National Patient Safety Goal. To reduce the number of nuisance electrocardiographic alarm signals in adult patients on the medical cardiovascular care unit. A quality improvement process was used that included eliminating duplicative alarms, customizing alarms, changing electrocardiography electrodes daily, standardizing skin preparation, and using disposable electrocardiography leads. In the cardiovascular care unit, the mean number of electrocardiographic alarm signals per day decreased from 28.5 (baseline) to 3.29, an 88.5% reduction. Use of a bundled approach to managing alarm signals decreased the mean number of alarm signals in a cardiovascular care unit.

Gradient-induced voltages on 12-lead ECGs during high duty-cycle MRI sequences and a method for their removal considering linear and concomitant gradient terms

To restore 12-lead electrocardiographic (ECG) signal fidelity inside MRI by removing magnetic field gradient-induced voltages during high gradient duty cycle sequences. A theoretical equation was derived to provide first- and second-order electrical fields induced at individual ECG electrodes as a function of gradient fields. Experiments were performed at 3T on healthy volunteers using a customized acquisition system that captured the full amplitude and frequency response of ECGs, or a commercial recording system. The 19 equation coefficients were derived via linear regression of data from accelerated sequences and were used to compute induced voltages in real-time during full resolution sequences to remove ECG artifacts. Restored traces were evaluated relative to ones acquired without imaging. Measured induced voltages were 0.7 V peak-to-peak during balanced steady state free precession (bSSFP) with the heart at the isocenter. Applying the equation during gradient echo sequencing, three-dimensional fast spin echo, and multislice bSSFP imaging restored nonsaturated traces and second-order concomitant terms showed larger contributions in electrodes further from the magnet isocenter. Equation coefficients are evaluated with high repeatability (ρ = 0.996) and are dependent on subject, sequence, and slice orientation. Close agreement between theoretical and measured gradient-induced voltages allowed for real-time removal. Prospective estimation of sequence periods in which large induced voltages occur may allow hardware removal of these signals.

Anaesthetic management for laparoscopic cholecystectomy in patient with situs inversus totalis.

Sir, Situs inversus totalis is an autosomal recessive congenital condition in which major thoracic and abdominal visceral organs are reversed from their normal position. We report anaesthetic management of a patient with situs inversus totalis who underwent laparoscopic cholecystectomy. A 61-year-old lady, a known hypertensive on medications, diagnosed to have situs inversus totalis presented for a laparoscopic cholecystectomy. On preanaesthetic evaluation, patient's vital parameters and biochemical investigations were within normal limits. Her chest X-ray revealed situs inversus with dextrocardia [Figure 1]. Electrocardiograph (ECG) showed T wave inversion in lead I, aVL, V2 to V6 with deep Q waves in lead I and aVL which was consistent with dextrocardia [Figure 2]. Echocardiography revealed dextrocardia with mild aortic regurgitation and normal left ventricular ejection fraction. Pulmonary function tests showed a peak expiratory flow rate of 200 L/min. In the operation theatre, ECG monitor was connected with left sided ECG leads on the right side and vice versa. After premedication, general anaesthesia (GA) was induced with intravenous induction agent thiopentone and muscle relaxation obtained with vecuronium. Intubation was performed with 8.0 mm internal diameter endotracheal tube and position checked by auscultation. Anaesthesia was maintained with 1% isoflurane in oxygen and nitrous oxide mixture. Regular tracheal and oral suctioning were done which revealed minimal secretions and peak airway pressures were closely monitored. The procedure was uneventful and patient made satisfactory recovery. Figure 1 Chest radiograph showing dextrocardia with clear lung fields Figure 2 Electrocardiograph showing T wave inversion in anterolateral leads Anaesthetic management of a patient of situs inversus includes workup for Kartagener's syndrome and other multisystem anomalies. Kartagener's syndrome is a condition with immotile cilia and a triad of bronchiectasis, sinusitis and situs inversus which affects 20% of patients with situs inversus.[1] Congenital heart diseases are present in more than 90% of cases with situs inversus with levocardia and in 3–5% of cases in situs inversus with dextrocardia.[2] Complete heart block is found to occur in over 20% of patients with situs inversus. Airway abnormalities may manifest as aglossia, hypoglossia or Goldenhar syndrome.[3] Electrocardiograph electrodes if normally placed in these patients will show inverted T waves in lateral leads resembling a lateral wall myocardial ischemia. In the preanaesthetic evaluation, this may prompt unnecessary workup for suspected myocardial ischemia. Electrodes are to be placed in the mirror position for correct tracing during the surgery. During intubation left endobronchial placement of the endotracheal tube may occur, since the left bronchus is more in line with the trachea. Central venous catheter must be placed cautiously under ultrasound guidance because of the likelihood of associated vascular anomalies. During defibrillation, paddles should be placed in reverse position on the upper left and lower right of the chest. There are case reports of prolonged paralysis after administration of succinylcholine in patients with situs inversus totalis and hence it is prudent to avoid depolarising muscle relaxants.[4] Pulmonary function tests play an important role in preoperative evaluation of the patients with Kartagener's syndrome. Physiotherapy, incentive spirometry, antibiotics and bronchodilators have a beneficial role in the preoperative preparation of the patient. It is prudent to avoid nasal intubation due to the associated sinusitis. Furthermore, inspired gases should be humidified to avoid viscid secretions. It is beneficial to induce and maintain GA with volatile anaesthetic due to the resultant bronchodilatation and reduced ventilatory depression in the early postoperative period. To conclude, apart from keeping in mind the various anomalies associated with situs inversus, appropriate modifications in anaesthesia technique is essential for smooth conduct of anaesthesia.

Proper skin preparation and electrode placement decreases alarms on a telemetry unit.

An estimated 85% to 99% of electrocardiographic (ECG) alarms are false, leading to alarm fatigue, which is associated with increased risk of death among hospitalized patients. The aim of this study was to examine the effect of proper skin preparation and electrode placement on frequency of ECG alarms on a telemetry unit. A prospective descriptive design was used to test the effect of proper skin preparation and ECG electrode placement. Purposive sampling of patients (n = 15) admitted to a telemetry hospital in a suburban Veterans Affairs Medical Center was used. Alarms were counted for 24 hours after admission, electrodes were replaced using proper technique, and alarms were counted for 24 hours after electrode change. Bootstrapping was used to double the sample size for analysis. Electrocardiographic alarms decreased significantly (P < .05) after proper skin preparation and electrode placement (95% confidence interval, 1.273-82.327). Proper skin preparation and ECG electrode placement reduced alarms. Reducing alarm frequency is vital to decreasing alarm fatigue and increasing patient safety.

Pulse Oximetry Measures a Lower Heart Rate at Birth Compared with Electrocardiography

To examine the effect of time after birth on heart rate (HR) measured by pulse oximetry (PO) (HRPO) and electrocardiography (ECG) (HRECG). HRECG and HRPO (collected at maximum sensitivity) were assessed in 53 term and preterm infants at birth. ECG electrodes and a PO sensor were attached as soon as possible and HRECG and HRPO were compared every 30 seconds from 1-10 minutes after birth. Data were compared using a Wilkinson signed-rank test. Clinical relevance (eg, HR <100 beats per minute [bpm] was tested using a McNemar test). Seven hundred fifty-five data pairs were analyzed. Median (IQR) gestational age was 37 (31-39) weeks. Mean (SD) starting time of PO and ECG data collection was 99 (33) vs 82 (26) seconds after birth (P = .001). In the first 2 minutes after birth, HRPO was significantly lower compared with HRECG (94 (67-144) vs 150 (91-153) bpm at 60 seconds (P < .05), 81 (60-109) vs 148 (83-170) bpm at 90 seconds (P < .001) and 83 (67-145) vs 158 (119-176) at 120 seconds (P < .001). A HR <100 bpm was more frequently observed with a PO than ECG in the first 2 minutes (64% vs 27% at 60 seconds (P = .05), 56% vs 26% at 90 seconds (P < .05) and 53% vs 21% at 120 seconds (P < .05). HR by ECG was verified by ultrasound for outflow from a subset of infants. In infants at birth, HRPO is significantly lower compared with ECG with clinically important differences in the first minutes.

Longitudinal hemodynamic measurements in swine heart failure using a fully implantable telemetry system.

Chronic monitoring of heart rate, blood pressure, and flow in conscious free-roaming large animals can offer considerable opportunity to understand the progression of cardiovascular diseases and can test new diagnostics and therapeutics. The objective of this study was to demonstrate the feasibility of chronic, simultaneous measurement of several hemodynamic parameters (left ventricular pressure, systemic pressure, blood flow velocity, and heart rate) using a totally implantable multichannel telemetry system in swine heart failure models. Two solid-state blood pressure sensors were inserted in the left ventricle and the descending aorta for pressure measurements. Two Doppler probes were placed around the left anterior descending (LAD) and the brachiocephalic arteries for blood flow velocity measurements. Electrocardiographic (ECG) electrodes were attached to the surface of the left ventricle to monitor heart rate. The telemeter body was implanted in the right side of the abdomen under the skin for approximately 4 to 6 weeks. The animals were subjected to various heart failure models, including volume overload (A-V fistula, n = 3), pressure overload (aortic banding, n = 2) and dilated cardiomyopathy (pacing-induced tachycardia, n = 3). Longitudinal changes in hemodynamics were monitored during the progression of the disease. In the pacing-induced tachycardia animals, the systemic blood pressure progressively decreased within the first 2 weeks and returned to baseline levels thereafter. In the aortic banding animals, the pressure progressively increased during the development of the disease. The pressure in the A-V fistula animals only showed a small increase during the first week and remained stable thereafter. The results demonstrated the ability of this telemetry system of long-term, simultaneous monitoring of blood flow, pressure and heart rate in heart failure models, which may offer significant utility for understanding cardiovascular disease progression and treatment.

Allergic contact dermatitis caused by self‐adhesive electrocardiography electrodes: a rare case with concomitant roles of nickel and acrylates

Allergic contact dermatitis caused by self‐adhesive electrocardiography electrodes: a rare case with concomitant roles of nickel and acrylates

Technical note: Electrocardiogram electrode repositioning for 320-row coronary CT angiography in patients with regular and recurrent premature ventricular contractions

Arrhythmias can compromise image quality and increase radiation exposure during coronary CT angiography (CTA). However, premature ventricular contractions (PVCs) can occur in a predictable recurrent and regular pattern (ie, bigeminy, trigeminy, quadrigeminy) with post-PVC compensatory pauses. Electrocardiographic (ECG) electrode repositioning can achieve relative amplification of the R waves of PVCs compared with R waves of sinus beats. This technical note describes how simple ECG electrode repositioning, combined with an absolute-delay strategy, facilitated selective R waves of PVC ECG triggering of image acquisition in 6 patients with PVC bigeminy or quadrigeminy at the time of 320-row coronary CTA. All 6 studies were single heartbeat acquisition scans with excellent image quality and a median effective radiation dose of 2.9 mSv (interquartile range, 2.1–3.8 mSv). Standard ECG electrode positions used for 2 patients with PVC bigeminy undergoing coronary CTA were associated with an acquisition over 2 heartbeats and effective radiation doses of 6.8 and 10.3 mSv, respectively. In conclusion, ECG electrode repositioning combined with an absolute-delay strategy for regularly recurring PVCs, such as ventricular bigeminy, facilitates high image quality and lower radiation dose during coronary CTA. This simple and straightforward technique can be considered for all patients with regular and recurrent PVCs undergoing coronary CTA.

Iatrogenic anetoderma of prematurity: a case report and review of the literature.

Anetoderma is a skin disorder characterized by focal loss of elastic tissue in the mid dermis, resulting in localized areas of macular depressions or pouchlike herniations of skin. An iatrogenic form of anetoderma has been rarely described in extremely premature infants and has been related to the placement of monitoring devices on the patient skin. Because of the increasing survival of extremely premature infants, it is easy to foresee that the prevalence of anetoderma of prematurity will increase in the next future. Although it is a benign lesion, it persists over time and can lead to significant aesthetic damage with need for surgical correction. Sometimes the diagnosis can be difficult, especially when the atrophic lesions become evident after discharge. Here, we report on a premature infant born at 24 weeks of gestation, who developed multiple anetodermic patches of skin on the trunk at the sites where electrocardiographic electrodes were previously applied. The knowledge of the disease can encourage a more careful management of the skin of extremely premature babies and aid the physicians to diagnose the disease when anetoderma patches are first encountered later in childhood.

An implantable instrument for studying the long-term flight biology of migratory birds

The design of an instrument deployed in a project studying the high altitude Himalayan migrations of bar-headed geese (Anser indicus) is described. The electronics of this archival datalogger measured 22 × 14 × 6.5 mm, weighed 3 g, was powered by a ½AA-sized battery weighing 10 g and housed in a transparent biocompatible tube sealed with titanium electrodes for electrocardiography (ECG). The combined weight of 32 g represented less than 2% of the typical bodyweight of the geese. The primary tasks of the instrument were to continuously record a digitised ECG signal for heart-rate determination and store 12-bit triaxial accelerations sampled at 100 Hz with 15% coverage over each 2 min period. Measurement of atmospheric pressure provided an indication of altitude and rate of ascent or descent during flight. Geomagnetic field readings allowed for latitude estimation. These parameters were logged twice per minute along with body temperature. Data were stored to a memory card of 8 GB capacity. Instruments were implanted in geese captured on Mongolian lakes during the breeding season when the birds are temporarily flightless due to moulting. The goal was to collect data over a ten month period, covering both southward and northward migrations. This imposed extreme constraints on the design's power consumption. Raw ECG can be post-processed to obtain heart-rate, allowing improved rejection of signal interference due to strenuous activity of locomotory muscles during flight. Accelerometry can be used to monitor wing-beat frequency and body kinematics, and since the geese continued to flap their wings continuously even during rather steep descents, act as a proxy for biomechanical power. The instrument enables detailed investigation of the challenges faced by the geese during these arduous migrations which typically involve flying at extreme altitudes through cold, low density air where oxygen availability is significantly reduced compared to sea level.

Electrocardiographic Practices

In 2004, practice standards for electrocardiographic (ECG) monitoring were published to address the need for an expanded use of ECG monitoring beyond heart rate and basic rhythm determination. This article reports the data collected from a survey distributed throughout the Veterans Healthcare Administration hospitals to determine the extent to which practice standards have been adopted. Survey data were used to identify the differences between actual practice and evidence-based standards. The results were divided into ECG electrode application, lead selection, alarm limits, monitoring capabilities, monitoring during patient transport, and education and competencies. The results confirm the need for improvement, including a thorough evaluation of facility practices and education. The data demonstrate the differences among actual practice and evidence-based recommendations.

Allergic contact dermatitis caused by self‐adhesive electrocardiography electrodes in an infant

Allergic contact dermatitis caused by self‐adhesive electrocardiography electrodes in an infant

Comparison of Twelve-Lead Electrocardiogram Using a Glove-Based Recording System With Standard Methodology

We tested the clinically relevant diagnostic accuracy of a new electrocardiographic (ECG) recording system incorporating all 10 ECG electrodes in a single-size glove worn on the patient's left arm and placed on the chest. The PhysioGlove (PG) was designed to allow fast, reproducible, electrode placement with only minimal training. The American College of Cardiology/American Heart Association ECG recording guidelines and others have repeatedly highlighted the unacceptable progressive deterioration in ECG accuracy mainly resulting from a performer's lack of proficiency and diligence, leading to frequent electrode misplacement. We studied 428 consenting adult patients with a broad spectrum of anthropomorphic characteristics and ECG and cardiovascular pathologic entities. The chest girth was measured to ascertain the single-size PG clinical diagnostic accuracy in ≥90% of this patient population. For each patient, a PG and standard-cable electrocardiogram were consecutively recorded and interpreted by experienced electrocardiographers. The study included 3 phases: phase 1, run-in (n = 120); phase 2, comparative diagnostic accuracy (n = 208); and phase 3, randomized, blinded, diagnostic accuracy (n = 100). Of the entire study population (n = 428), 92% fit the chest girth range of 85 to 118 cm (34 to 47 in.), representing the reference standard clinical diagnostic PG chest girth range. The phase 2 PG diagnostic accuracy was 91.3% for entire chest girth range and 95.7% for the 89.4% of patients with a chest girth within the reference range. The mean PG diagnostic accuracy in phase 3 was 93% (95% confidence interval 89% to 95%). In conclusion, compared with standard-cable electrocardiograms, the PG demonstrated excellent diagnostic accuracy (93% to 95.7%) in ≥90% of a typical western adult patient population. The PG's ease of use and minimal training requirements offer a promising tool to markedly improve ECG clinical diagnostic accuracy in most adult western patients.