Spin Physics, Inc.

Lti Biomedical, Inc.

Eastman-kodak Company

Minnesota Mining and Manufacturing Company

University of Pennsylvania

Neil J Griffith

James U Lemke

Brian S Kelleher

Carl T Brighton

Solomon R Pollack

Ward M Calaway

Robert A Schneider

Fredrick J Jeffers

Theodore B Hill

David Pienkowski

Peter A Balnave

Dan A Vance

James Crosby

Bruce C Tostevin

A sloping tape guide is provided for an arcuately scanning tape drive so that tension per unit width of a magnetic tape is equalized in the head/tape contact zone on a front face of a head assembly of the arcuate scanner. The tape wraps over the circular edge of the magnetic head assembly. As a consequence, the tension per unit width is higher at the center of the tape that at the edges. The low tension at the edges of the tape results in poor head to tape contact in these regions and consequently unacceptable signal performance. This invention overcomes these difficulties by providing a means to equalize tension per unit width across the tape. The sloping tape guide has a front sloping flat surface which is bounded by top and bottom edges and first and second side edges, the first side edge being closer to the lat surface slopes rearwardly from its first edge to its second edge away from the periphery of the head assembly. The second edge is concave so that top and bottom edge portions of the sloping surface have a longer path length than a center portion of the sloping surface. By wrapping the tape around the second edge, the top and bottom edge portions of the magnetic tape traverse a longer tape path length than the middle portion of the magnetic tape thereby increasing tension per unit width at the edge portions of the tape as the tape makes transducing contact with the magnetic heads scanning across the width of the tape. Deadband portions at top and bottom edges of the tape are thereby eliminated to increase the efficiency of the arcuate scanner.

Edge tensioning sloping tape guide for arcuately scanning tape drive

A non-invasive, portable electromagnetic therapeutic method and apparatus for promoting the healing of damaged or diseased living tissue including fractured bone and in particular nonunion or delayed union bone fractures are described. The method and apparatus involve generating a signal having a series of substantially symmetric voltage cycles of bursted pulses having narrow pulse widths on the order of 0.5 to 20 microseconds and converting the signal into an electromagnetic field which extends into an area for desired tissue healing. The portable noninvasive apparatus can be readily worn or carried by a patient and is capable of generating an energy-efficient symmetrical signal coacting with a coil for transducing the signal into electromagnetic pulses.

Electromagnetic method and apparatus for healing living tissue

An electrical to electromagnetic transducer for applying electromagnetic energy to damaged potions of the living body, which provides high efficiency generation of electromagnetic fields for electromagnetic therapy by directing electromagnetic radiation to the damaged body part. Electromagnetic radiation is initially generated by a dipole consisting of a bar of high permeability material wrapped with an electrically conductive coil. The dipole is placed between a conductive shield and the damaged body part. An electrical signal passes through the coil which causes a magnetic field to be generated through and around the high permeability material. The field radiation pattern of the dipole is directed toward the damaged body part by a conductive shield. Magnetic fields which are generated away from the damaged body part intersect the conductive shield and establish eddy currents. These eddy currents in turn generate magnetic fields opposite and nearly equal to the magnetic fields generated by the electromagnetic source. These resultant redirected electromagnetic fields then reinforce the electromagnetic field directed towards the damaged body part and diminish the electromagnetic field directed away from the damaged body part.

Shielded electromagnetic transducer

A portable non-invasive apparatus for electro-therapeutic stimulation of tissue and bone healing readily worn or carried by a patient, capable of generating an energy-efficient signal coacting with a suitable transducer of the signal, thereby realizing portability and stimulating tissue and bone healing.

Portable electro-therapy system

A solenoid device for treatment of body tissue such as bones or other regions with pulsed signals comprises a flexible flat belt for encircling a body part or cast surrounding a body part containing tissue to be treated. The belt has a plurality of parallel conductors extending along its length and has its opposite ends offset by one or more conductor spacings. The resultant aligned conductor ends are connected together to form at least one continuous coil, with the resultant unconnected outer conductor ends at opposite sides of the belt comprising inputs across which a suitable electrical signal can be connected. An adjustment device or buckle is mounted on the belt to allow the diameter of the belt to be adjusted. The buckle traps a doubled over portion of the belt circumference which is adjustable in length to change the diameter of the device to closely fit the underlying body part or cast.

Device for electromagnetic treatment of living tissue

The invention teaches that if a 'shorted' electrically conductive turn--deposited on a magnetic substrate--is employed to sense recorded signal flux, then the underlying substrate will efficiently support flux induced about the shorted turn . . . and such induced flux will correspond proportionately to the recorded signal flux. In accordance with the invention, an MR element is so situated that it senses induced flux about the shorted turn at a location thereof that is remote from the medium whose signal flux is to be reproduced.

Inductively-coupled, thin-film M-R head

A gapped magnetic core is comprised of core material of one type. Gapping material, which is magnetically different from the core material, 'completely' bridges the core gap. The gapping material has a lower magnetic saturation level than does the core material; and thus the gap cannot act as a transducer gap until it becomes magnetically saturated. When gapped cores as described above are stacked to form a multitrack head, the effects of inductive coupling between the cores is prevented; i.e., when, for example, one core of the stack of cores is actuated by magnetically saturating its gap, all other cores of the stack are inherently immune to inductive coupling to the actuated core. This is because induced flux in all non-actuated cores is magnetically short-circuited through their respective magnetic gaps.

Selectively actuable magnetic head

An electrically conductive element is employed in proximity to a thin film magnetic structure. The conductive element has current applied to it which is just sufficient to maintain, by field coupling between the thin film structure and the conductive element, the given magnetic orientation of the thin film structure, this occurring despite the application of a signal field tending to reorient the magnetization of the thin film structure. Such current is, therefore, the analog of the applied signal field and, since the magnetization of the thin film structure, by virtue of induced magnetic feedback, does not appreciably change direction, harmonics of any signal field applied to the thin film structure, and noise, are not manifested in the current analog.

Magnetoresistive head employing field feedback

High track density multitrack magnetic heads are batch-fabricated from a stack of wafers which are photolithographically processed to provide lands and grooves on the wafers. Thin magnetic films are deposited in the grooves; and coils respectively inductively cooperative with the films are photolithographically formed about the films, the lands serving both to provide track-to-track spacing and to protect the magnetic films from magnetostriction-producing stress.

Growing community of inventors

San Diego, CA, United States of America

Neil J Griffith