BACK BRACES AND ABDOMINAL girdles improve

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1 ORIGINAL ARTICLE Respiratory Effects of Combined Truncal and Abdominal Support in Patients With Spinal Cord Injury Nicholas Hart, MRCP, Isabelle Laffont, MD, Annie Perez de La Sota, MD, Michèle Lejaille, Gilles Macadou, Michael I. Polkey, MRCP, PhD, Pierre Denys, MD, PhD, Frédéric Lofaso, MD, PhD ABSTRACT. Hart N, Laffont I, Perez de La Sota A, Lejaille M, Macadou G, Polkey MI, Denys P, Lofaso F. Respiratory effects of combined truncal and abdominal support in patients with spinal cord injury. Arch Phys Med Rehabil 2005;86: Objective: To determine whether a custom girdle, designed to provide truncal stability and abdominal support, will improve pulmonary function, enhance inspiratory muscle activity, and reduce the sensation of respiratory effort in patients with spinal cord injury (SCI). Design: Pulmonary function, transdiaphragmatic pressure time product (PTP di ), twitch (Tw Pdi) and maximal transdiaphragmatic pressures (Pdi), and perception of respiratory effort (Borg Rating of Perceived Exertion score) were measured with and without an abdominal girdle in a seated position. Setting: Rehabilitation hospital. Participants: Ten patients with posttrauma SCI (injury level, C5-T6). Intervention: Application of the abdominal girdle. Main Outcome Measures: Borg score and measures of lung volumes, dynamic abdominal compliance, and Tw Pdi and maximal Pdi. Results: Wearing of the girdle was associated with a lower Borg score (P.002) and reduced functional residual capacity (P.006) but increased inspiratory capacity (P.02) and forced vital capacity (P.02). Although there was a decrease in dynamic abdominal compliance (P.001) and an increase in PTP di (P.02), this was accompanied by an increase in both Tw Pdi (P.02) and maximal Pdi (P.03). Conclusions: The custom girdle reduced the sensation of respiratory effort in patients with SCI by optimizing the operating lung volumes and decreasing abdominal compliance, which enhanced diaphragm performance. Key Words: Diaphragm; Paraplegia; Rehabilitation; Tetraplegia by American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation From the Service de Physiologie-Explorations Fonctionnelles, Rééducation Fonctionnelle et Centre d Innovation Technologique Hôpital Raymond Poincaré, Garches, France (Hart, Laffont, Perez de La Sota, Lejaille, Macadou, Polkey, Lofaso); Respiratory Muscle Laboratory, Royal Brompton Hospital, London, UK (Hart, Polkey); and Inserm U 492, Créteil, France (Lofaso). Supported by a European Respiratory Society Long Term Fellowship, the Association Française Contre Les Myopathies, the Scadding-Morriston Davies Joint Respiratory Medicine Fellowship, and the Assistance Publique des Hôpitaux de Paris. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated. Reprint requests to Frédéric Lofaso, MD, PhD, Service de Physiologie- Explorations Fonctionnelles, Hôpital Raymond Poincaré, AP-HP, Garches, France, f.lofaso@rpc.ap-hop-paris.fr /05/ $30.00/0 doi: /j.apmr BACK BRACES AND ABDOMINAL girdles improve truncal stability in patients with spinal cord injury (SCI). Although earlier studies 1,2 suggested that girdles and back braces provide little benefit to pulmonary function, subsequent studies 3-5 have shown that simple abdominal binding techniques with subjects seated improve lung volumes. For more than 40 years, our hospital has specialized in the production of made-to-measure girdles for SCI patients, 6 and our clinical impression has been that, in a seated position, SCI patients have a reduction in breathlessness when a girdle is worn. The purpose of the girdles is to support the trunk and the paralyzed abdominal muscles. Consequently, there is a decreased abdominal compliance 7 that can improve the diaphragmatic function by restituting the expanding effect of the diaphragm at the zone of apposition. 8 Nevertheless, this decrease in abdominal compliance could result in 2 contrasting effects. On the one hand, by enhancing diaphragmatic performance there could be an improvement in inspiratory pressure generation and volume displacement, a modification that would be expected to reduce breathlessness. However, a reduction in abdominal compliance could also increase the diaphragmatic load, which would have the opposite effect and actually heighten respiratory difficulty. Our purpose in this study was to assess the effect of these custom girdles, with both truncal and abdominal support, on the sensation of respiratory effort, pulmonary function, diaphragmatic load, and diaphragm strength in patients with SCI during spontaneous breathing while in a seated position. METHODS 1447 Girdle Design The girdles are made of 100% cotton thousand-pea material, 50% cotton and 50% polyester plush, galvanized steel stays, and stretchable synthetic fabric. The girdle has nonstretchable material for the anterior and posterior parts and a stretchable material for the sides, reinforced by 8 steel stays. A fastener with 4 or 5 self-adhesive straps is positioned ventrally (fig 1). Participants Our local ethics committee approved the study, and all patients gave informed consent. To be included, patients had to satisfy the following criteria: (1) have an American Spinal Injury Association grade A posttraumatic spinal lesion of the lower cervical to midthoracic level (C5-T6), 9 (2) be in a stable clinical condition, and (3) be wheelchair bound and wearing a girdle according to the practice in our hospital. Measurements Testing with and without the girdle was performed in random order with the patients seated in their wheelchairs. Pulmonary function tests were performed with and without a girdle at the same time on 2 consecutive days. Diaphragmatic and inspiratory muscle function was assessed in both conditions on another day of the same week, again at the same time of day. We used a modified Ratings of Perceived Exertion

2 1448 ABDOMINAL SUPPORT IN SPINAL CORD INJURY, Hart Fig 1. The girdle. 10-point Borg scale 10 to evaluate the patients sensation of respiratory effort with and without the girdle. Borg Score Although the Borg score, as a measure of respiratory effort, has generally been used during exercise, 10 it has also been used to assess the respiratory response to inspiratory and expiratory muscle loading Furthermore, because the combined effect of gravity and the abdominal contents acts as a respiratory load in SCI patients in the sitting position, 2,15,16 we reasoned the Borg score could be used as an indicator of respiratory effort. The Borg scale is a vertical line with gradations from 0 to 10, with each value corresponding to a verbal descriptor of respiratory sensation. Care was taken to minimize the influence of investigator bias on the subjects perceived respiratory sensation response by allowing the subjects to complete the Borg score outside the laboratory. We reasoned that this would provide a more reliable result because the patient would not be subjected to all the external factors, such as the invasive measuring equipment. Patients were instructed to assess their respiratory effort in a nonlaboratory setting while sitting with the girdle on and off and to return the Borg score questionnaire within 15 days after completing the study. Pulmonary Function Tests Pulmonary function testing was performed with a Vmax 229 SensorMedics System, a according to standard guidelines. 17 Spirometry, flow-volume curves, lung volumes (including functional residual capacity [FRC]) and maximal expiratory static mouth pressure (PEmax) at total lung capacity (TLC) were measured. Pattern of Breathing and Inspiratory Muscle Function Pattern of breathing and inspiratory muscle function tests were performed on the third day, again in a random order, with and without the girdle. Flow was measured by using a Fleisch no. 2 pneumotachograph. b We used respiratory inductive plethysmography c (RIP) to obtain thoracic and abdominal contributions to tidal volume (VT). RIP bands were positioned on the chest above the nipple line and on the abdomen at the umbilical level. RIP was calibrated by using the semiquantitative single-position method during natural breathing (qualitative diagnostic method 18 ) and was also calibrated with the integrated flow signal, which was confirmed by isovolumic maneuvers. 19 As the movement of the ribcage and abdomen were considered with 2 degrees of freedom, these 2 compartments should define lung expansion. Thus, VT can be considered as the sum of abdominal volume change and thoracic volume change measured by RIP bands; the ribcage contribution (RC) to VT (RC VT) was calculated as VT. 19 Transdiaphragmatic pressure (Pdi) was obtained by measuring the differential between gastric pressure (Pgas) and esophageal pressure (Pes) by using a catheter-mounted pressure transducer system. d The catheter was passed through the nose after local anesthesia was administered to the nasal mucosa. The position of the catheter was assessed by asking each subject to perform sharp sniff maneuvers while we observed the deflection of the signal. The simplest technique is to advance both the esophageal and gastric transducer into the stomach, as judged by a positive deflection during a sniff, and then to withdraw the catheter until the proximal pressure transducer deflection becomes negative, indicating that the transducer has entered the esophagus. The catheter is then withdrawn another 10cm, with its appropriate placement being verified by the occlusion test. 20 Transcutaneous carbon dioxide tension (PtcCO 2 ) was recorded continuously. e All signals were digitized at 128Hz and sampled for a subsequent analysis by a tester blinded to the study by using an analogic and numeric acquisition system. f Both conditions were studied after a 30-minute rest while breathing through a mouthpiece. Cervical magnetic phrenic nerve stimulation, using a 90-mm circular coil powered by a Magstim stimulator, g was used to determine the twitch transdiaphragmatic pressure (Tw Pdi), 21 which is a sensitive and reliable nonvolitional technique for assessment of diaphragm function. 21 All the magnetic stimulations were applied at FRC, determined by the end-expiratory Pes level. 22,23 Mean value of Tw Pdi was calculated from at least 5 phrenic nerve stimulations at maximal power output. The Pdi change was also measured during volitional maximum inspiratory effort (Pdi max ) at FRC against an occluded inspiratory valve. 21 Data Analysis Respiratory parameters were measured during the last 5 minutes of resting breathing. From the flow tracings, we measured inspiratory time (T I ) and respiratory frequency (f R ). VT was obtained from the integrated flow signal and minute ventilation (V E) was obtained as the product of f R and VT. Mean swings of Pes (Pes swing ), Pgas (Pgas swing ), and Pdi (Pdi swing ) were measured from the same resting breathing period. Transdiaphragmatic pressure time product (PTP di ) was also calculated from the same period and used as an indicator of diaphragmatic effort. PTP di was calculated from the area under the Pdi versus time curve and was expressed as cmh 2 O per minute. 21 Dynamic lung compliance (C Ldyn ) was calculated as the ratio of VT to the difference in Pes at points of zero flow, corresponding to the start and end of inspiration. 24 Dynamic abdominal compliance (C ABdyn ) was calculated as the ratio of the abdominal contribution to VT to the difference in Pgas at the beginning and ending of inspiration. These methods are dynamic adaptations of the static measurements of abdominal compliance 25 and lung compliance. 24,26,27 Statistics All data are given as mean standard deviation (SD). Comparisons between variables in the same patients were made using paired t tests. The level of significance was set at 5%.

3 ABDOMINAL SUPPORT IN SPINAL CORD INJURY, Hart 1449 Subject No. Sex/Age (y) Height (cm) Weight (kg) Table 1: Patient Characteristics Injury Level Duration Since Injury (mo) Smoker PaCO 2 (kpa) PaO 2 (kpa) ph (IU) 1 M/ C5 7 Ex M/ C Ex M/ C Never F/ C7 27 Never F/ T4-5 5 Never NA NA NA 6 F/ C5 3 Never M/ T4 6 Ex M/ C Never M/ C7 11 Never F/ T5 3 Never NOTE. Blood gases were measured in a seated position without an abdominal girdle. Abbreviations: Ex, ex-smoker; F, female; M, male; NA, not available; Never, never smoked. RESULTS Participants Ten consecutive subjects with SCI were recruited during routine clinical evaluations. All patients had a history of traumatic fracture or dislocation of the spine (7 patients had tetraplegia), but none required any form of ventilatory assistance. Patients demographic and arterial blood gas characteristics in the seated position without a girdle are shown in table 1. Pulmonary Function The changes in pulmonary function, with and without the girdle, are shown in table 2. Although there was a decrease in FRC when the girdle was applied, the accompanying increase in inspiratory capacity (IC) contributed to the increase in forced vital capacity but without any observed change in expiratory residual volume. Peak expiratory flow and forced expiratory volume in 1 second were improved by the girdle, but these effects were not associated with an increase in PEmax. Table 2: Effect of the Girdle on Pulmonary Function IVC (L) Percent FVC (L) Percent IC (L) FRC (L) Percent ERV (L) RV (L) Percent TLC (L) Percent FEV 1 (L/s) Percent PEF (L/s) Percent PEmax (cmh 2 O) NOTE. Values are mean SD in body temperature and ambient pressure (BTPS). Abbreviations: ERV, expiratory reserve volume; FEV 1, forced expiratory volume in 1 second; FVC, forced vital capacity; IC, inspiratory capacity; IVC, inspiratory vital capacity; PEF, peak expiratory flow; RV, residual volume. Breathing Pattern and Respiratory Mechanics The patients pattern of breathing is shown in table 3. The girdle conferred no change in the breathing pattern, except for an increase in the thoracic component to VT. Although C Ldyn did not change with application of the girdle, C ABdyn fell by more than 50% (table 4). Inspiratory Muscle Function The girdle produced an increase in PTP di. Furthermore, in conjunction with the decrease in FRC, increase in IC, decrease in C ABdyn, and increase in diaphragmatic load, we also observed an increase in Tw Pdi and Pdi max. Borg Score The Borg score was lower with application of the girdle, falling from to (P.002). DISCUSSION In seated SCI patients, abdominal and truncal support with a custom girdle reduced the sensation of respiratory effort, expressed as a lower in Borg score. This reduction in the perception of respiratory difficulty is associated with an improvement in the operating lung volumes. Although there was an increase in diaphragmatic load, this was accompanied by a compensatory increase in diaphragm strength, which was coupled with a reduction in the abdominal compliance and an increase in the operating length of the diaphragm (shown as a decrease in the FRC and an increase in IC). This increase in diaphragm strength after application of the girdle was observed during both the volitional and nonvolitional assessment diaphragm function. Previous data of able-bodied subjects has shown that as lung volume increases between residual volume and FRC, the Tw Table 3: Effect of the Girdle on Ventilation VT (ml) f R (breaths/min) V E (L/min) T I (s) VT/T I (L/s) RC-VT (%) PtcCO 2 (mmhg) NOTE. Values are mean SD in BTPS.

4 1450 ABDOMINAL SUPPORT IN SPINAL CORD INJURY, Hart Table 4: Effect of the Girdle on Respiratory Mechanics and Inspiratory Muscle Function C ABdyn (ml/cmh 2 O) C Ldyn (ml/cmh 2 O) Pes swing (cmh 2 O) Pgas swing (cmh 2 O) Pdi swing (cmh 2 O) PTP di (cmh 2 O s min 1 ) Pdi max (cmh 2 O) Tw Pdi (cmh 2 O) NOTE. Values are mean SD. Dynamic compliances, pressure swings, and pressure time product were obtained during the same periods of quiet breathing as used for ventilatory parameters measurements presented in table 3. Pdi is reduced by approximately 5cmH 2 O/L. 21 This is the result of the inverse relation between the length and force exhibited by skeletal muscle, which is reflected as an indirect correlation between lung volume and diaphragm strength. 21 In the current study, the abdominal girdle decreased FRC by more than 400mL, and thus this would have a significant effect on the increase in Tw Pdi. Furthermore, isovolumic changes in ribcage and abdominal compartment configuration influence Tw Pdi, 21 such that displacement of volume from the thoracic to the abdominal compartment results in a decrease in Pdi. 28 Thus, the change in abdominal position with application of the girdle in the current study would be expected to cause an increase in Tw Pdi. Nevertheless, the fall in abdominal compliance with application of the girdle could also influence the observed increase in diaphragm performance. Because of the abdominal muscle paralysis in patients with SCI, one could expect a reduction in abdominal compliance, with the resultant relation between abdominal compliance and diaphragm performance being dependent on 2 mechanisms. First, the elevation in Pgas observed during inspiration with the girdle on could be expected to act at the zone of apposition of the diaphragm with the ribcage; this would tend to expand the lower ribcage 29,30 and, as observed, increase the esophageal component to the Pdi. Second, the decrease in abdominal compliance may reduce the caudal excursion of the diaphragm, which would organize the fibers of the diaphragm in a more axial position in relation to the ribcage. This would allow the diaphragm to directly lift the ribcage at its level of insertion during inspiration. According to these mechanisms, the clinical consequences of abdominal binding, as shown by McCool et al 3 and confirmed by the current study, are to increase the ribcage dimensions but at a similar lung volume. 16,31,32 In patients with SCI, as opposed to the able bodied, 31 pulmonary function is enhanced in the supine relative to the seated position, 16,32 with the increase in vital capacity being a consequence of a decrease in residual volume. 4 Although earlier studies found little beneficial effect of abdominal girdles and back braces on pulmonary function in seated SCI patients, 1,2 subsequent studies have found an improvement in lung volume when the abdomen is bound. 3-5 In particular, abdominal strapping abolishes this postural dependence of residual volume, 4 reduces FRC, and increases IC. 3 Although the current data are consistent with these latter observations, 3-5,15 when simple abdominal binding techniques that provide little support were used, the improvements in pulmonary function we found were achieved with custom girdles that were designed to enhance truncal stability and provide abdominal support in patients with SCI. 1,2 Therefore, there appears to be a beneficial respiratory effect with this type of custom girdle, which is similar to the results of previous abdominal binding studies, 3-5 but in contrast to the earlier studies in which girdles and back braces were used. 1,2 This finding may be explained, in part, by the more elastic nature of this type of girdle, which could augment the expansion of the thoracic and abdominal compartments. 4 The earlier, more rigid girdles may have not only hindered inspiratory expansion on the lower ribcage but also may have provided less abdominal support. This is also in keeping with our previous observations 33 that severe abdominal muscle spasm accompanying SCI, which can be considered in physiologic terms to be similar to a rigid abdominal corset, causes a substantial increase in the load on the diaphragm without a corresponding increase in diaphragm strength. This results in breathlessness from the imbalance between inspiratory muscle load and capacity. The overall recommendation from these data is that patients will gain respiratory benefit by wearing custom girdles that have a flexible component incorporated into their design. Although we assessed patients with different SCI levels, we only recruited those patients with paralysis of their abdominal muscles and preserved diaphragm function. The main difference between patients with tetraplegia and paraplegia is the function of the parasternal, intercostal, and scalene muscles, which may modify the ribcage motion. Most patients with tetraplegia breathe with an unassisted diaphragm and may have an inspiratory decrease in the upper ribcage anteroposterior diameter, 7 whereas patients with paraplegia have a more uniform ribcage expansion. 8 Nevertheless, even if the 3 patients with paraplegia were excluded from the analysis, our overall results would be the same. CONCLUSIONS Flexible custom girdles, which provide a combination of both truncal and abdominal support, reduce the sensation of respiratory effort by improving the operating lung volumes, decreasing abdominal compliance and increasing diaphragm strength in patients with cervical and midthoracic traumatic SCI. Although there is an increase in diaphragmatic load, this is counterbalanced by an increase in the contractile properties of the diaphragm, which occurs as a result of both an increase in the operating length of the diaphragm and a reduction in abdominal compliance. Careful consideration must be given to girdle design to combine both the beneficial effects of truncal and abdominal support with improvements in respiratory function. Acknowledgments: We thank Bernard Bussel and Olivier Dizien for permitting us to study the patients under their care. We also thank Cécile Huguet and the workshop staff of the Raymond Poincaré Hospital for the design and production of rehabilitation equipment and for their valuable technical assistance. References 1. Haas A, Lowman EW, Bergofsky EH. Impairment of respiration after spinal cord injury. Arch Phys Med Rehabil 1965;46: Maloney FP. Pulmonary function in quadriplegia: effects of a corset. Arch Phys Med Rehabil 1979;60: McCool F, Pichurko B, Slutsky A, Sarkarati M, Rossier A, Brown R. Changes in lung volume and rib cage configuration with abdominal binding in quadriplegia. J Appl Physiol 1986;60: Estenne M, De Troyer A. Mechanism of the postural dependence of vital capacity in tetraplegic subjects. Am Rev Respir Dis 1987;135:

5 ABDOMINAL SUPPORT IN SPINAL CORD INJURY, Hart Estenne A, Van Muylem A, Gorini M, Kinnear W, Heilporn A, De Troyer A. Effects of abdominal strapping on forced expiration in tetraplegic patients. Am J Respir Crit Care Med 1998;157: Grossiord A, Jeager-Denavit O, Miranda G. Contribution à l étude des troubles ventilatoires des para et tétraplégiques. Semaine Hôpitaux 1963;15: Estenne M, De Troyer A. Relationship between respiratory muscle electromyogram and rib cage motion in tetraplegia. Am Rev Respir Dis 1985;132: De Troyer A, Estenne A. Chest wall motion in paraplegic subjects. Am Rev Respir Dis 1990;141: Clinical assessment after acute cervical spinal cord injury. Neurosurgery 2002;50(3 Suppl):S Borg GA. Psychophysical bases of perceived exertion. Med Sci Sports Exerc 1982;14: Peiffer C, Silbert D, Cerrina J, et al. Respiratory sensation related to resistive loads in lung transplant recipients. Am J Respir Crit Care Med 1996;154(4 Pt 1): Lavietes MH, Sanchez CW, Tiersky LA, Cherniack NS, Natelson BH. Psychological profile and ventilatory response to inspiratory resistive loading. Am J Respir Crit Care Med 2000;161: Peiffer C, Poline JB, Thivard L, Aubier M, Samson Y. Neural substrates for the perception of acutely induced dyspnea. Am J Respir Crit Care Med 2001;163: Hours S, Lejaille M, Pozzi D, et al. Perceived inspiratory difficulty in neuromuscular patients with primary muscle disorders. Neuromuscul Disord 2004;14: Mead J, Banzett R, Lehr J, Loring S, O Cain C. Effect of posture on upper and lower rib cage motion and tidal volume during diaphragm pacing. Am J Respir Crit Care Med 1984;130: Baydur A, Adkins RH, Milic-Emili J. Lung mechanics in individuals with spinal cord injury: effects of injury level and posture. J Appl Physiol 2001;90: Quanjer PH, Tammeling GJ, Cotes JE, Pedersen OF, Peslin R, Yernault JC. Lung volumes and forced ventilatory flows. Report Working Party Standardization of Lung Function Tests, European Community for Steel and Coal. Official Statement of the European Respiratory Society. Eur Respir J Suppl 1993;16: Sackner MA, Watson H, Belsito AS, et al. Calibration of respiratory inductive plethysmograph during natural breathing. J Appl Physiol 1989;66: Konno K, Mead J. Measurement of the separate volume changes of rib cage and abdomen during breathing. J Appl Physiol 1967; 22: Baydur A, Behrakis PK, Zin WA, Jaeger M, Milic-Emili J. A simple method for assessing the validity of the esophageal balloon technique. Am Rev Respir Dis 1982;126: ATS/ERS Statement on respiratory muscle testing. Am J Respir Crit Care Med 2002;166: Laroche CM, Mier AK, Moxham J, Green M. The value of sniff esophageal pressures in the assessment of global inspiratory muscle strength. Am Rev Respir Dis 1988;138: Laporta D, Grassino A. Assessment of transdiaphragmatic pressure in humans. J Appl Physiol 1985;58: Mead J, Whittenberger J. Physical properties of the human lung measured during spontaneous respiration. J Appl Physiol 1953;5: Konno K, Mead J. Static volume-pressure characteristics of the rib cage and abdomen. J Appl Physiol 1968;24: Turner JM, Mead J, Wohl ME. Elasticity of human lungs in relation to age. J Appl Physiol 1968;25: Yernault JC, Englert M. Static mechanical lung properties in young adults. Bull Physiopathol Respir 1974;10: Chen R, Kayser B, Yan S, Macklem PT. Twitch transdiaphragmatic pressure depends critically on thoracoabdominal configuration. J Appl Physiol 2000;88: De Troyer A, Sampson M, Sigrist S, Macklem PT. Action of costal and crural parts of the diaphragm on the rib cage in dog. J Appl Physiol 1982;53: Loring SH, Mead J. Action of the diaphragm on the rib cage inferred from a force-balance analysis. J Appl Physiol 1982;53: Allen SM, Hunt B, Green M. Fall in vital capacity with posture. Br J Dis Chest 1985;79: Linn WS, Adkins RH, Gong H Jr, Waters RL. Pulmonary function in chronic spinal cord injury: a cross-sectional survey of 222 southern California adult outpatients. Arch Phys Med Rehabil 2000;81: Laffont I, Durand MC, Rech C, et al. Breathlessness associated with abdominal spastic contraction in a patient with C4 tetraplegia: a case report. Arch Phys Med Rehabil 2003;84: Suppliers a. SensorMedics Corp, Savi Ranch Pkwy, Yorba Linda, CA b. Fleisch, Lausanne, Switzerland. c. Respitrace Plus; Non Invasive Monitoring Systems, 1666 Kennedy Causeway, Ste 400, North Bay Village, FL d. Gaeltec, Dunvegan, Isle of Skye, Scotland IV55 8GU. e. TCM3; Radiometer A/S, Åkandevej 21, 2700 Brønshøj, Denmark. f. MP100; Biopac Systems, 42 Aero Camino, Goleta, CA g. Magstim Co, Spring Gardens, Whitland, Carmarthenshire, Wales, SA34 0HR, UK.