J H Battocletti

Medical College of Wisconsin, Milwaukee, WI, United States

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Publications (45)140.36 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Animal model study of eight healthy commercial cats was conducted. To determine whether pulsed electromagnetic field (PMF) stimulation results in improvement of function after contusive spinal cord injury in cats. PMF stimulation has been shown to enhance nerve growth, regeneration, and functional recovery of peripheral nerves. Little research has been performed examining the effects of PMF stimulation on the central nervous system and no studies of PMF effects on in vivo spinal cord injury (SCI) models have been reported. PMF stimulation was noninvasively applied for up to 12 weeks to the midthoracic spine of cats with acute contusive spinal cord injury. The injury was produced using a weight-drop apparatus. Motor functions were evaluated with the modified Tarlov assessment scale. Morphologic analyses of the injury sites and somatosensory-evoked potential measurements were conducted to compare results between PMF-stimulated and control groups. There was a significant difference in locomotor recovery between the PMF-stimulated and control groups. Although not statistically significant, PMF-stimulated spinal cords demonstrated greater sparing of peripheral white matter and smaller lesion volumes compared to controls. Somatosensory-evoked potential measurements indicated that the PMF-stimulated group had better recovery of preinjury waveforms than the control group; however, this observation also was not statistically significant because of the small sample size. This preliminary study indicates that pulsed magnetic fields may have beneficial effects on motor function recovery and lesion volume size after acute spinal cord injury.
    Spine 01/2004; 28(24):2660-6. · 2.16 Impact Factor
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    ABSTRACT: Pulsed magnetic field (PMF) stimulation was applied to mammalian neurons in vitro to influence axonal growth and to determine whether induced current would direct and enhance neurite growth in the direction of the current. Two coils were constructed from individual sheets of copper folded into a square coil. Each coil was placed in a separate water-jacketed incubator. One was energized by a waveform generator driving a power amplifier, the other was not energized. Whole dorsal root ganglia (DRG) explant cultures from 15-day Sprague-Dawley rat embryos were established in supplemented media plus nerve growth factor (NGF) at concentrations of 0-100 ng/mL on a collagen-laminin substrate. Dishes were placed at the center of the top and bottom of both coils, so that the DRG were adjacent to the current flowing in the coil. After an initial 12 h allowing DRG attachment to the substrate floor, one coil was energized for 18 h, followed by a postexposure period of 18 h. Total incubation time was 48 h for all DRG cultures. At termination, DRG were histochemically stained for visualization and quantitative analysis of neurite outgrowth. Direction and length of neurite outgrowth were recorded with respect to direction of the current. PMF exposed DRG exhibited asymmetrical growth parallel to the current direction with concomitant enhancement of neurite length. DRG cultures not PMF exposed had a characteristic radial pattern of neurite outgrowth. These results suggest that PMF may offer a noninvasive mechanism to direct and promote nerve regeneration.
    Bioelectromagnetics 06/2000; 21(4):272-86. · 2.02 Impact Factor
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    ABSTRACT: Esophageal conductance measurements were correlated with hemodynamic events in 9 dogs chronically instrumented for measurement of left ventricular (LV) and aortic pressures, LV short axis and descending aortic diameters, and aortic blood flow. A four-electrode conductance catheter was positioned in the esophagus. Both an internal and an internal/external configuration were examined during anesthesia with hemodilution, pulmonary lavage and dobutamine infusion. LV stroke volume was altered by caval occlusion at each intervention. Stroke conductance was highly correlated to aortic or LV diameters and stroke volume over a range of diameters depending on the electrode configuration. Esophageal conductance measurements are directly influenced by local hemodynamic events adjacent to the site of measurement.
    IEEE Transactions on Biomedical Engineering 05/2000; 47(4):559-64. · 2.35 Impact Factor
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    ABSTRACT: Pulsed magnetic field (PMF) stimulation was applied to mammalian neurons in vitro to influence axonal growth and to determine whether induced current would direct and enhance neurite growth in the direction of the current. Two coils were constructed from individual sheets of copper folded into a square coil. Each coil was placed in a separate water-jacketed incubator. One was energized by a waveform generator driving a power amplifier, the other was not energized. Whole dorsal root ganglia (DRG) explant cultures from 15-day Sprague–Dawley rat embryos were established in supplemented media plus nerve growth factor (NGF) at concentrations of 0–100 ng/mL on a collagen–laminin substrate. Dishes were placed at the center of the top and bottom of both coils, so that the DRG were adjacent to the current flowing in the coil. After an initial 12 h allowing DRG attachment to the substrate floor, one coil was energized for 18 h, followed by a postexposure period of 18 h. Total incubation time was 48 h for all DRG cultures. At termination, DRG were histochemically stained for visualization and quantitative analysis of neurite outgrowth. Direction and length of neurite outgrowth were recorded with respect to direction of the current. PMF exposed DRG exhibited asymmetrical growth parallel to the current direction with concomitant enhancement of neurite length. DRG cultures not PMF exposed had a characteristic radial pattern of neurite outgrowth. These results suggest that PMF may offer a noninvasive mechanism to direct and promote nerve regeneration. Bioelectromagnetics 21:272–286, 2000. © 2000 Wiley-Liss, Inc.
    Bioelectromagnetics 04/2000; 21(4):272 - 286. · 2.02 Impact Factor
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    ABSTRACT: An alternative coil system to the Helmoholtz coil-pair is described for the stimulation of biological tissue and cells: a relatively large box coil made of copper or aluminum sheet stock. The design is based on the principal determinant of the induced electric field, namely, the magnetic vector potential (A), in the equation, [formula: see text]. The second term in the equation is needed when boundaries of the conducting medium are in close proximity to the region of interest, such as in a culture dish. An electric surface charge builds up on the boundaries to generate an electric field which cancels [formula: see text] at the surface. The effectiveness of the new coil is demonstrated in a study of the outgrowth enhancement of axons from rat embryonic dorsal root ganglia.
    IEEE Transactions on Biomedical Engineering 04/2000; 47(3):402-8. · 2.35 Impact Factor
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    ABSTRACT: Traditional methods for estimating the slope alpha and offset volume Vp for determining real-time chamber volume by the conductance catheter technique are not suited to measurements made in the aorta due to the relatively low resistivity of the aortic wall. We developed three distinct three-dimensional finite element models of the conductance catheter and surrounding tissues in order to predict alpha and Vp and to examine the nature of the electric field near the aortic wall. A heterogeneous isotropic model of the catheter, aorta and surrounding tissues accurately predicted the values of alpha and Vp. A homogeneous anisotropic model was developed to examine the effects of anisotropy of blood and the layers of the aortic wall on measured values of resistance, alpha and Vp. This model demonstrated that anisotropy of blood and aortic wall tissue can increase the values of both alpha and Vp. Finally, a three-dimensional homogeneous isotropic rectangular model allowed examination of the effects of catheter position. This model showed small effects of catheter position on measured resistance (9.7% increase) and larger effects on alpha (21.2% decrease) and Vp (41.9% increase). We conclude the following: the FEA models may lead to accurate estimate values of alpha and Vp in vivo. The unique anisotropic conductive properties of the layers of the aortic wall contribute to the high observed values of alpha and Vp in the aorta. Finally, catheter position has a proportionately greater effect on alpha and Vp than on measured resistance. The results of this study should assist in the determination of aortic mechanical properties using conductance catheter measurements of vessel dimension.
    Annals of Biomedical Engineering 01/1999; 27(2):151-9. · 3.23 Impact Factor
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    ABSTRACT: The goal of this investigation was to determine if the conductance catheter technique for chamber volume measurement could be applied in vivo to determine real-time phasic aortic segmental volume. A four-electrode conductance catheter was used to measure time-varying resistance of the descending thoracic aorta in open-chest, anesthetized dogs. Resistance was converted to segmental volume and the slope correction factor (alpha) and parallel conductance volume (Vp) were determined. The results showed excellent linear correlation between conductance and sonomicrometric segmental volume. The correction factors alpha and Vp were found to be empirically related to average vessel diameter. The relatively high values for the slope correction factor (alpha=4.59+/-0.17 SEM) were found to be primarily related to low-resistivity shunt paths probably originating in the periadventitial aortic wall and to a lesser extent to changes in flow-induced increases in blood resistivity, hematocrit, catheter position, and other adjacent tissue resistivity. The results demonstrate that correction factors empirically derived from measurements of mean aortic diameter could be used to determine absolute real-time phasic segmental volume, cross-sectional area, or diameter. The conductance technique may possess the same potential for determining aortic mechanical properties which has already been demonstrated for determining ventricular mechanical properties.
    Annals of Biomedical Engineering 04/1998; 26(3):431-40. · 3.23 Impact Factor
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    ABSTRACT: Despite its undisputed utility for determining changes in ventricular pressure-volume relationships, the conductance catheter technique has not been proven reliable for measuring absolute volume. This limitation is due to violations of the assumptions inherent in the cylindrical model on which the method is based (i.e., homogeneous electric field and no leakage current). The purpose of this investigation was to relate cylindrical model correction factors to the physical environment of the catheter and to the cylindrical equation. Physical measurements of saline-filled, nonconductive cylinders using a four-electrode conductance catheter were compared with a three-dimensional finite element model of the physical apparatus. These measurements were incorporated into a parallel conductance model to relate physical parameters to corrections in the cylindrical equation for volume measurement. Excellent agreement between measured and modeled data was found. Results demonstrated a nonlinear relationship between the field nonhomogeneity correction factor (alpha) and cylinder diameter. The relationship between alpha and diameter was consistent with a theoretical extrapolation of cylinder diameter toward infinity. An inverse relationship between alpha and the parallel conductance volume (Vp) was also clarified. The parallel conductance model was able to demonstrate opposite effects of the physical presence of the catheter body and electrodes, which tended to cancel out any net effect on measured conductance. Results of this investigation and the developed finite element model clarify the nature of the correction terms in the cylindrical model and may lead to greater application of the conductance technique.
    Annals of Biomedical Engineering 12/1996; 25(1):126-34. · 3.23 Impact Factor
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    ABSTRACT: We have previously shown that neurite outgrowth from 6-day chick embryo dorsal root ganglia (DRG) in vitro was stimulated when nerve growth factor (NGF) and pulsed magnetic fields (PMF) are used in combination. 392 DRGs were studied in a field excited by a commercial PMF generator. We have now analyzed an additional 416 DRGs exposed to very similar PMF's produced by an arbitrary wavefrom generator and power amplifier. We reproduced our previous findings that combination of NGF and bursts of asymmetric, 220 microsecond-wide, 4.0 mT-peak pulses induced significantly (p < 0.05) greater outgrowth than NGF alone, that fields without NGF do not significantly alter outgrowth, and that, unlike NGF alone, 4.0 mT fields and NGF can induce asymmetric outgrowth. The asymmetry does not seem to have a preferred orientation with respect to the induced electric field. Analysis of the data for the entire 808 DRGs confirms these findings. Importantly, we find similar results for pulse bursts repeated at 15 or 25 Hz.
    Bioelectromagnetics 02/1996; 17(4):293-302. · 2.02 Impact Factor
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    ABSTRACT: This investigation examined the feasibility of applying the conductance catheter technique for measurement of absolute aortic segmental volume. Aortic segment volume was estimated simultaneously in vitro by using the conductance catheter technique and sonomicrometer crystals. Experiments were performed in five isolated canine aortas. Vessel diameter and pressure were altered, as were the conductive properties of the surrounding medium. In addition, a three-dimensional finite-element model of the vessel and apparatus was developed to examine the electric field and parallel conductance volume under different experimental conditions. The results indicated that in the absence of parallel conductance volume, the conductance catheter technique predicted absolute changes in segmental volumes and segmental pressure-volume relationships that agreed closely with those determined by sonomicrometry. The introduction of parallel conductance volume added a significant offset error to measurements of volume made with the conductance catheter that were nonlinearly related to the conductive properties of the surrounding medium. The finite-element model was able to predict measured resistance and parallel conductance volume, which correlated strongly with those measured in vitro. The results imply that absolute segmental volume and distensibility may be determined only if the parallel conductance volume is known. If the offset volume is not known precisely, the conductance catheter technique may still be applied to measure absolute changes in aortic segmental volume and compliance.
    Annals of Biomedical Engineering 01/1996; 24(6):675-84. · 3.23 Impact Factor
  • J.H. Battocletti, T.A. Knox
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    ABSTRACT: Finite element analysis techniques are applied to the sphere. The sphere is subdivided into non-rectangular linear hexahedra except at the polar axis, where they are wedges. An automatic mesh generation computer program, based on the work of Sepulveda (1984), is used to assign node and element numbers. Equation numbers are assigned to minimize the bandwidth of the “stiffness matrix”. To avoid computation artifacts, it is important to subdivide the sphere into elements whose sides are approximately equal. Two examples are presented, (a) the ideal magnet, and (b) a three-layered conducting sphere. To demonstrate the versatility of the method described in the paper, a low-resistivity region was introduced in the three-layered conducting sphere to show how the equipotential and current flow lines are affected
    IEEE Transactions on Magnetics 12/1994; · 1.42 Impact Factor
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    ABSTRACT: 31P nuclear magnetic resonance spectroscopy (NMRS) measurements were made on human T2 and T3 vertebral bodies. The bone mineral content (BMC) of isolated vertebral bodies minus the posterior elements and disks was measured using (1) NMRS on a 3.5 T, 85 mm bore GE Medical Systems NT-150 superconducting spectrometer, (2) a Lunar Corporation DPX-L dual-energy X-ray absorptiometry (DXA) scanner in an anterior-posterior (AP) orientation, (3) a Norland Corporation XR26 DXA scanner, also in an AP direction, and (4) a Norland Corporation model 2600 dual-photon absorptiometry (DPA) densitometer in both the AP and superior-inferior (SI) directions. Vertebral body volumes were measured using a water displacement technique to determine volume bone mineral densities (VBMD). They were then compressed to failure using an electrohydraulic testing device, followed by ashing in a muffle furnace at 700 degrees C for 18 h. Correlations of BMC between NMRS and DPA, DXA and ashing were excellent (0.96 < or = r < or = 0.99); in a one-way analysis of variance (ANOVA) test, means were not statistically different at a p level of 0.757. The correlations of VBMD between NMRS and the other methods were not as good (0.83 < or = r < or = 0.95); in a one-way ANOVA test, means were not statistically different at a p level of 0.089. BMC was a better predictor of ultimate compressive failure than VBMD for all six methods. For NMRS, the regression coefficient for BMC was r2 = 0.806, compared with r2 = 0.505 for VBMD. NMRS may prove an alternative to present methods of determining bone mineral.
    Osteoporosis International 06/1994; 4(3):129-37. · 4.04 Impact Factor
  • J.H. Battocletti, H.A. Kamal, T.J. Myers, T.A. Knox
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    ABSTRACT: Passive shimming of a relatively low-cost, medium-size, permanent magnet employing neodymium-iron-boron magnet material by the appropriate addition of steel is described. The magnet is for a low-field (0.33 T, 5.688 MHz) <sup>31</sup>P NMR spectrometer built for the measurement of bone mineral in the human wrist and heel. The fuzzy logic and expert system features of the computer program used to enhance the shimming are discussed. The shimming procedure is described, and results are discussed
    IEEE Transactions on Magnetics 08/1993; · 1.42 Impact Factor
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    ABSTRACT: The purpose of this study was to examine the force-deformation characteristics of football helmets subjected to compressive loading on the crown surface. Tests were conducted at quasi-static and dynamic rates of loading. Energies were computed from the force-deformation data. The padding systems represented by the helmets differed in their ability to absorb energy under varying loading rates. Helmets using pneumatic or combination pneumatic-foam padding systems were the most successful while suspension helmets were able to absorb the least amount of energy. The evaluation of energy absorption characteristics is an alternative method of describing the effectiveness of football helmets in preventing head injury.
    Bio-medical materials and engineering 02/1993; 3(1):15-24. · 1.09 Impact Factor
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    ABSTRACT: First Page of the Article
    Engineering in Medicine and Biology Society, 1991. Vol.13: 1991., Proceedings of the Annual International Conference of the IEEE; 12/1991
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    ABSTRACT: Magnetically induced current density has been measured in different concentrations of saline solution and in the cerebral cortex of cats in vivo. The results show that the current density decreases with distance from the stimulating coil and with increasing resistivity. The presence of the cranium attenuates the current density in the cortical tissue. The studies show that it is possible to measure directly current densities induced by magnetic fields
    Engineering in Medicine and Biology Society, 1989. Images of the Twenty-First Century., Proceedings of the Annual International Conference of the IEEE Engineering in; 12/1989
  • J.H. Battocletti, T.J. Myers, R. Scheidt
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    ABSTRACT: Nuclear magnetic resonance phosphorus spectroscopy (NMRS) is a method of measuring the mineral content of bone as a diagnostic tool for osteoporosis. A description is given of the design and construction of a low-field spectrometer for the human wrist. It uses a small-size permanent magnet of neodymium-iron-boron. The questions of whether a low-field spectrometer is sensitive enough to measure the phosphorus mineral content of bone and to what extent the phosphorus in soft tissue affects the measurement of bone mass are discussed
    Engineering in Medicine and Biology Society, 1989. Images of the Twenty-First Century., Proceedings of the Annual International Conference of the IEEE Engineering in; 12/1989
  • J.H. Battocletti
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    ABSTRACT: The numerical solution of Poisson's equation, which describes the dielectric and/or conductive properties of biological tissue, is presented. Only two-dimensional problems are demonstrated; the third dimension is considered to be of unit length, with no boundaries at the two ends. The finite-element approach can handle any kind of nonisotropy and has the advantage that electrodes can be placed anywhere with very slight changes in the computer program. Further applications of the method are considered
    Engineering in Medicine and Biology Society, 1989. Images of the Twenty-First Century., Proceedings of the Annual International Conference of the IEEE Engineering in; 12/1989
  • J.H. Battocletti, T.J. Myers
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    ABSTRACT: A 0.105-T (1050-G) whole-body permanent-magnet structure has been designed by 3-D and 2-D, finite-element analysis, constructed using simple manufacturing techniques, and passively shimmed to yield a homogeneity factor of 105 p.p.m. over a 25-cm- (10-in) diameter sphere. Ceramic type 10 magnetic material is used. An expert computer program that utilizes all the shimming data for additional homogeneity improvement has been written. The program, which includes over 1000 inhomogeneity conditions, could be used for shimming other magnet structures. Transient temperature tests show that the magnetic flux density at the center of the working air gap can change significantly in the short term, so that temperature stability of the magnet environment is required
    IEEE Transactions on Magnetics 10/1989; · 1.42 Impact Factor
  • C. Reuter, J.H. Battocletti, J. Myklebust, D. Maiman
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    ABSTRACT: The use of very strong pulsed magnetic fields to stimulate excitable tissue has been investigated. The advantage of this method as opposed to the conventional method, electrical stimulation, is that it is noninvasive and virtually painless. However, the drawbacks are that the site of stimulation is less well defined than for electrical stimulation and repetition rates for stimuli are often limited to 1 or 2 per second. In this study, various stimulation parameters for magnetic stimulation of the peripheral nerves in the arms were investigated. Systems were developed that would yield stimulation. The median nerve in the upper arm was stimulated and the results were plotted in a method similar to the strength-duration curve.< >
    Engineering in Medicine and Biology Society, 1988. Proceedings of the Annual International Conference of the IEEE; 12/1988

Publication Stats

260 Citations
140.36 Total Impact Points

Institutions

  • 1972–1999
    • Medical College of Wisconsin
      • • Department of Anesthesiology
      • • Department of Neurosurgery
      Milwaukee, WI, United States
  • 1996–1998
    • Marquette University
      • Department of Biomedical Engineering
      Milwaukee, Wisconsin, United States
  • 1993
    • U.S. Department of Veterans Affairs
      Washington, Washington, D.C., United States
  • 1979
    • University of Wisconsin - Milwaukee
      Milwaukee, Wisconsin, United States
    • National Heart, Lung, and Blood Institute
      Maryland, United States