Chest electrodes

Kerwin AJ, McLean R, Tegelaar H. A method for the accurate placement of chest electrodes in the taking of serial electrocardiographic tracings. Can Med Assoc J 1960 82 258. 

Rautaharju PM, Park L, Rautaharju FS, Crow R. A standardized procedure for locating and documenting ECG chest electrode positions consideration of the effect of breast tissue on ECG amplitudes in women. J Electrocardiol 1998 31 17. 

Sensoria Heapsylon EEC Socks Bra, compression shirt Step counting, speed, calories, altitude and distance tracking, cadence, foot landing technique and weight distribution Heart rate Electronic device magnetically snaps at sock cuff textile sensors integrated in socks electrically conductive materials (Heapsylon, 2014) Electronic device snaps onto garment at chest electrodes need to be moistened before use electrically conductive materials (Heapsylon EEC, 2014)... 

Clinical evaluation is underway to test transvenous electrodes. Transvenous leads permit pacemakers to be implanted under local anesthesia while the patient is awake, greatly reducing recovery time and risk. As of 1996, the generation of implantable defibrillators requires a thoracotomy, a surgical opening of the chest, in order to attach electrodes to the outside of the heart. Transvenous electrodes would allow cardiologists to perform pacemaker procedures without a hospital or the use of general anesthesia. 

In their work74 on the ECT of melanoma tumors in hamsters, Schauble et al. (U.S.A.) implanted a 1.5 V battery as the power source. A stainless steel point electrode was placed in the tumor, either as anode or as cathode and a counter electrode made of plane wire mesh was applied to the skin of the chest. Three different current levels were used 3 mA 0.5 mA 1 pA. The two higher currents produced necrosis of the tumor at the dose leve of lh/day for 4 consecutive days. A more pronounced effect was observed with anode in the tumor and cathode outside it. 

A tremendous amount of work has been devoted to ORR on all kinds of surfaces but Bockris and Khan [245] were forced to conclude that no generalizations as to mechanism have been made, and, correspondingly, no key to the treasure chest of fast catalysis... has been found. Despite decades of research and even though the effect of electrode material on the 02 reduction reaction (ORR) has been reviewed extensively, Yang and McCreery [246] concluded even more recently that detailed mechanisms remain elusive and that for carbon surfaces there is no consensus on the mechanism... 

MODIFICATIONS OF THE METHOD The technique described by Salazar et al. (1961) uses a stainless steel electrode which is inserted into a coronary artery in the dog and which delivers anodal current to the intravascular lumen. The electrode is positioned under fluoroscopic control which complicates the method. The technique was modified by Rom-son et al. (1980). They placed the electrode directly into the coronary artery of open-chest anaesthetized dogs. 

Six of the 12 leads of the ECG are placed directly on the chest wall. By international convention, these electrodes are placed in predetermined locations and record activity from sites directly over specific parts of the heart. The other six leads are associated with recordings from the limbs. 

A pacemaker generator is implanted under the skin in the chest wall, and it is connected to an electrode attached to the vagus nerve in the neck area, which has direct extensions into the brain. The pacemaker is receptive to programming and instructions given externally by computer, and thus specific parameters of intensity and frequency, as well as other technical variables, can be controlled and adjusted according to the specific needs of the patient (Figure B.2). 

A routine ECG is composed of 12 leads. Sis are called limb leads (I, II, III, aVR, aVL, and aVF), because they are recorded between arm and leg electrodes, and six are called precordial or chest leads (Vj, V2, V3, V4, V5, and Vg) and are recorded across the sternum and left precordium. Each lead records the same electrical impulse but in a different position relative to the heart. Areas of pathology shown on the ECG can be localized by analyzing differences between the tracing in question and what is known to be normal in the 12 different leads. 

Needle electrodes were placed in intercostal muscles in 10 subjects who received 70-150 pg of sarin by the single-breath technique of vapor administration (MOD13). Although eight noted chest tightness, none had changes in whole blood cholinesterase, and there were no abnormalities in the electrical pattern from the muscles. It was concluded that muscular abnormalities did not contribute to the sensation of dyspnea. 

The above-lesion EMG-based menu selections employ surface-EMG signals fi om electrodes placed at above-lesion locations on the patient s chest. The thus obtained EMG signal (see Figure 31.8) serves to map a pattern of upper-trunk posture that has been shown [5,7,27], to predict intended body function, corresponding to the four menus above (stand, left step, right step, and sit menus), with an accuracy of better than 99.8%. In this case, no finger controls are needed. 

With only two chest EGG electrodes, it is possible to monitor... 

The most validated method is prediction of TBW from four-electrode whole-body transfer impedance measurements at 50 kHz. It is not really a whole-body measurement because the results are dominated by the wrist and ankle segments with very little influence from the chest because of the large cross-sectional area. By using more than four electrodes, it is possible to measure more than one body segment. With two electrodes at each hand and foot, the body impedance can, for instance, be modeled in five segments arms, legs, and chest. 

The self-adhesive electrodes are patches wired to the patient through conductive flexible adhesive which holds the electrode in place, tightly against the skin. Adhesive electrodes are shown in Figure 14.6. They are disposable and are applied to the chest before the dehvery of shock. Adhesive electrodes are left in place for reuse in case subsequent shocks are needed. Electrodes are usually applied with both electrodes on the anterior chest as shown in Figure 14.7, or in an anterior-to-posterior position, as shown in Figure 14.8. 

FIGURE 14.7 Cross-sectional view of the chest showing position for standard anterior wall (precordial) electrode placement. Lines of presumed current flow are shown between the electrodes on the skin surface. (Modified from Tacker WA (ed). 1994. Defibrillation of the Heart ICDs, AEDs and Manual, St. Louis, Mosby-Year Book. With permission.)... 

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