Applicator head for electromagnetic treatment of an afflicted body region

The invention contemplates a specific coil configuration adapted for application to particular regions of the body, for use in treating a selected such region with pulsed electromagnetic signals which are induced within the body as electric voltage and concomitant current signals which alter the growth, repair and maintenance behavior of living tissues and cells within the body region under treatment.

BACKGROUND OF THE INVENTION 
This invention relates to the treatment of living tissues and/or cells by 
altering their interaction with charged species in their environment. More 
particularly, the invention relates to an electromagnetic body-treatment 
device for surgically non-invasive modification of the growth, repair and 
maintenance behavior of living tissues and cells by a specific and 
selective change in electrical environment. 
Ryaby, et al., U.S. Pat. Nos. 4,105,017, 4,266,532 and 4,266,533 describe 
means for effecting surgically non-invasive direct inductive coupling to 
an afflicted body region, whereby one or more electric voltage and 
concomitant current signals conform to a highly specific pattern and have 
been found to develop therapeutically beneficial treatment of the 
afflicted region, as for example in the enhancement of repair of bone 
fractures, non-unions, and the like. In general, the involved treatment 
head or heads have involved one or more large coils, which have served 
well for the treatment of large-member bones, as in leg regions. And 
various special-purpose coil and head configurations have been disclosed 
for specific treatments. In general, it may be said that it has been 
preferred practice to employ a treatment-head configuration in which two 
like coils are electrically connected in flux-aiding relation and have 
flexibly articulated connection to enable strapped application on opposite 
sides of an afflicted limb, and with the coils on a common axis of 
magnetic-flux development through the afflicted region. However, for 
certain injuries, such as bone injury in the scaphoid region of the arm, 
it becomes very awkward, bothersome, and inconvenient to use the 
conventional articulated-coil technique, in that use of the arm must be 
severely curtailed, due primarily to treatment-head considerations. 
BRIEF STATEMENT OF THE INVENTION 
It is an object of the invention to provide a new approach to 
treatment-head design in equipment of the character indicated, with a view 
to reducing bulk and simplifying application to an afflicted region of the 
body. 
It is a specific object to provide an improved treatment head of the 
character indicated for application to scaphoid and other outer-arm 
regions. 
The invention achieves these objects with a single multi-turn electrical 
coil which is so bundled and deformed as to establish two like loops in 
spaced substantially parallel planes, with crossover of equally spaced 
regions of the coil, the crossover regions being a significant element in 
the relatively rigid positional spacing of the two loops. Upon exciting 
the coil with pulsed electrical signals as disclosed in said Ryaby, et al. 
patents, one obtains a flux-aiding coaction between the two loops whereby 
relatively uniform flux distribution characterizes the region bounded by 
and between the loops. 
In one embodiment, fabric separately encases the two loops and the 
crossover region by which they are integrally connected, so that the 
treatment head is of generally U-shape, for side-entry of the afflicted 
region via the open end of the U-shape; a flexible strap and fastener 
selectively closes the open end of the U-shape. In another embodiment, 
fabric encasement of the coils establishes an overall tubular 
configuration for limb insertion within and along the length of the tube, 
the respective loops of the coil defining the shape of the ends of the 
tubular configuration.

Referring initially to FIG. 1, the invention is shown in application to a 
single coil 10 of multiple turns of insulated wire, the ends of the coil 
having lead connection at 11 to a flexible cable 12 for removable 
connection via a plug 13, to a pulse-signal generator 14. Such a signal 
generator and the character of signals produced thereby have been 
described in said Ryaby, et al. patents, so that further description 
thereof is not now needed. 
For treatment of bone injury in the scaphoid region, as suggested by the 
phantom outline 15 of an arm in FIG. 1, the single coil 10 is suitably of 
about 60 turns of B & S gauge-12 copper wire, initially wound to a 
diameter of 23 cm and then bundled. Diametrically opposed locations of the 
bundle are then selected for crossover adjacency, and the peripherally 
equal segments bounded by said locations are subjected to a half-turn 
twist, resulting in an intermediate, substantially figure-eight appearance 
of the bundle. The figure-eight appearance defines two equal loops A-B, 
connected by the crossover region (C), and the figure-eight bundle is 
further bent so that the loops A-B are in spaced substantially parallel 
relation, with integral spacing and semi-rigid retention of the spacing of 
loops A-B, via crossover region C. Bending into the indicated shape will 
be understood to be performed against one or more suitable templates, and 
shape retention and bundle integrity are served by taped wrap of the 
bundle, as by electrician's adhesive tape 16 (FIGS. 4 and 5). The 
resulting configuration, for the indicated initial winding to 23 cm 
diameter, establishes loops A-B of 3.75-inch mean diameter and at 3.5-inch 
mean spacing. 
The above-described formative steps are seen to produce an integral 
single-coil structure which is the electrical and magnetic equivalent of 
two coils, formed by the respective loops A-B, which are necessarily of 
effective diameter D (FIG. 3), less than half the diameter to which the 
single coil was originally developed. Upon excitation, each of the loops 
A-B performs as a separate coil on a common axis 17 of magnetic-flux 
development, and by reason of the half-turn at crossover region C, the 
flux development at A-B is flux-aiding. For purposes of better visualizing 
the flux-development axis 17 in FIG. 1, separate intercepts are indicated 
at 17'-17" where axis 17 passes through the respective planes of loops A 
and B. And, for reasons indicated in conjunction with FIG. 13 of said 
Ryaby, et al. patents '532 and '533, it is preferred that the spacing S 
between loops A-B (i.e., between intercepts 17'-17") be substantially 
equal to or less than the effective diameter D of loops A-B, thus 
promoting relative uniformity of flux density in a generally cylindrical 
volume of treatment zone within and between loops A-B. 
As best seen in the side view of FIG. 4, the described deformation of coil 
10 establishes a generally U-shaped profile wherein loops A and B are the 
arms of the U-shape so that application to an afflicted limb region can be 
laterally of the axis 17, via the open end of the U-shape. In the case of 
bone fracture, the orthopedic surgeon will first have prepared the limb 
for recovery, by conventional application of a cast, and in doing so, he 
will preferably have integrated a post into the cast, with the post 
projecting a short distance outside the cast, as a means of reference to 
assure desired alignment for electromagnetically applied therapy. The 
provision of such a post or locating key, for inclusion in the cast and 
for coaction with an electromagnetic treatment head, is described in 
connection with FIGS. 7A and 8 in said Ryaby, et al. '532 patent; and 
similar locating coaction with the treatment head of the present invention 
is available by providing a rigid non-conductive plate 18, as of 
fiberglass-reinforced epoxy, bonded to the inner side of one of the loops, 
here shown as loop A. Plate 18 is seen in FIG. 4 to be centrally apertured 
at 19, on axis 17, for the keying or locating purposes indicated and 
described at greater length in the Ryaby, et al. '532 patent. 
For cosmetic and better-handling purposes, it is preferred to encase the 
described structure in a fabric material 20. Such material may be a length 
of woven or knitted tubing or hose, into which the described U-shape is 
inserted, to provide separate fabric encasing of the respective loops A-B 
and of the crossover connection therebetween, the ends of the encasement 
being closed as by stitching and allowing only for external availability 
of the lead cable 12 and its plug 13. It is preferred that such encasing 
fabric be rugged, as for example of woven glass fiber, and that separable 
fastening means be carried by fabric 20 for selective closure of the open 
end of the U-shape. Preference is indicated that hook and loop materials, 
known by the trademark Velcro, be used for this purpose. Therefore, as 
shown, the outer exposed surface of the fabric encasement 20 carries a 
finishing ply of loop material 21, and a flexible belt 22 extending from 
the encasement material at one of the ends of the U-shape carries an inner 
ply or facing 23 of hook material, it being noted that the locale of 
leadcable (12) access is at lateral offset from belt 22. 
In placing the described treatment head over a cast of the character 
indicated, entry is via the open end of the U-shape, until engagement of 
the locating post or key of the cast, in the coacting aperture 19 of the 
locating plate 18, via a corresponding aperture 19' in material 20, the 
latter being locally bonded to plate 19. Once thus located, the coil 
structure A-B-C is sufficiently compliant to permit compression of the 
arms of the U-shape against the cast, and retention of the compression via 
lapped engagement of hook material 23 over loop material 21, to hold a 
closure of the U-shape. 
The described application of the treatment head is really only needed 
during the intermittent times of electromagnetic therapy. Therefore, the 
hook and loop closure may be disengaged and the treatment head removed, 
during periods between treatments, it being understood that the patient 
may use his free arm for removal and for reapplication of the treatment 
head, when needed. 
FIGS. 6, 7 and 8 illustrate another mode of use of the coil configuration 
A-B-C of FIG. 1, wherein the axis 17 of magnetic-flux development is 
oriented longitudinal to the afflicted limb 15. For such purposes, the 
plate 18 of FIG. 4 is replaced by a plate 25 (FIG. 8) which is rigid to at 
least one of the loops A-B and which extends therebetween, preferably at a 
location diametrically opposite the crossover location C. As shown, plate 
25 is rigid to both loops A-B, and its locating aperture 26 is on a spring 
tab 27, the latter being defined by horseshoe-piercing of plate 25. Upon 
longitudinal insertion of limb 15 and its cast into such a treatment head, 
manipulation is continued until tab aperture 26 registers with the 
locating key of the cast, whereupon tab 27 resiliently snaps in to retain 
the correct location, i.e., in which the afflicted region is 
longitudinally centered between loops A-B. 
As with the embodiment of FIGS. 1 to 5, it is preferred that the treatment 
head in the mode of FIGS. 6 to 8 be fabric-encased, as the same appears in 
FIG. 7, wherein an outer sleeve 30 will be understood to surround both 
loops A and B, and the crossover region C; and an inner sleeve 31 lines 
the generally cylindrical space within loops A-B and region C. This result 
is accomplished either by stitching the ends of sleeves 30-31 to each 
other to complete the casing, or by employing a single sleeve which is 
outside-out at region 30 and tucked into and back on itself to be 
outside-in, at region 31, the remaining ends of regions 30-31 being then 
peripherally stitched to each other to complete the encasing. Again, as at 
19-19' in FIG. 4, the inner region 31 will be understood to be apertured 
(not shown) in register with tab aperture 26 and to be bonded to tab 27 
around such aperture. 
The described structure will be seen to meet stated objects. Bulk is 
reduced and electrical connections are simplified by reliance upon a 
single multi-turn coil 10. The initially wound diameter is to be 
understood to be purely illustrative, in that different initially wound 
diameters will clearly permit development of different effective loop 
diameters D and spacings S, as appropriate for size of cast and limb or 
other body region to be treated; a range of 18 cm to 25 cm initially wound 
diameters has, to date, been found to serve special applications of the 
character indicated. Nor is the wire size or number of turns of the coil 
to be considered limiting, because these factors will be understood to be 
as appropriate for the particular signal levels delivered by generator 14, 
in order to develop desired specific induced electrical voltage and 
concomitant current signals within the afflicted body region under 
treatment. 
While the invention has been described in detail for a preferred form and 
modes of use, it will be understood that modifications may be made without 
departure from the scope of the invention. For example, as illustrated in 
FIG. 8, the loops A-B may each describe almost a complete circular course, 
interrupted only to minimal angular extent .alpha. to accommodate the 
crossover region. It may be observed, however, that with such angular 
extent .alpha. as large as almost 90 degrees (as the same appears by 
inspection of FIGS. 1 and 6), the treatment head is an effective 
instrumentality for transducing the pulsed-signal output of generator 14 
into therapeutically beneficial induced voltages and concomitant currents 
within the body zone under treatment.