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Description  |
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BACKGROUND
1. Field of Invention
This invention relates to the field of medical apparatus, particularly to a
medical device for immobilizing a patient's head during treatment or
examination by tomographic or X-ray apparatus or the like. Also the head
immobilizer of the invention can be used to position a patient's head in
any precise position, identical to a previously-held position.
2. Description of Prior Art
During certain medical treatments and examinations of a patient, his or her
head must be held in a fixed, rigid position. Specifically the head, or
another part of a patient's anatomy, must be held very rigidly during the
following exemplary types of procedures: surgical procedures, including
dentistry, emergency medical care, physical and occupational therapy,
tomographic examinations (multiple X-rays taken using a CAT (computer
axial tomography) scanner, NMR (nuclear magnetic resonance) tomographic
scanner examinations ("pictures" taken in a similar fashion), X-ray
malignancy treatment procedures (radiation beams directed at a focus in
the body from a plurality of angles), etc. This is because tomographic and
similar processes involve patient irradiations or the taking of multiple
pictures from many angles over a period of time, usually a few minutes, to
enable a computer to provide a composite cross section of the head. If the
head (or other anatomical part) is allowed to move during the process, the
resultant cross-sectional picture will be distorted and blurred and of
little medical value.
Heretofore various methods and devices were used to immobilize the head for
these processes.
In some, the head was cradled in a form-fitting rest. However such cradles
or rests left much to be desired since they did not hold the head rigidly
and thus the patient could easily move it during the process.
In others, the head was clamped, either from top to bottom, side to side,
in the mouth, or with a combination of these methods. While such clamps
could immobilize the head, they were usually extremely uncomfortable for
the patient since force from the clamps, when applied for an extended
period of time, caused trauma to the patient. If the clamps were padded
sufficiently to avoid trauma, they then were too resilient to hold the
patient rigidly.
In still others, a clamping device was actually screwed into the patient's
head, usually the cheekbones, under surgical anaesthesia. While this
device held the patient's head in a very immobile manner, patients
obviously found it extremely traumatic, painful, disfiguring, and
uncomfortable.
In a further device, the patient was held by an air-impedance sheet draped
over the patient's torso, which sheet was held in position against the
patient by a vacuum source in communication with the underside of the
sheet. This device did not fully immobilize the patient and also it was
not feasible to use it to hold a patient's head because the sheet would
block the patient's nose or mouth.
In addition to their foregoing disadvantages, most of the aforementioned
devices also suffered from a lack of position repeatability. I.e., if the
physician desired to reposition the patient in precisely the same position
as previously used for a repeat treatment or diagnosis, e.g., for checking
the patient's progress after treatment or for repeating a therapeutic
treatment, most of the aforementioned devices could not be used to
reposition the patient in precisely the same position in which he or she
was previously held.
In addition to holding the head for medical procedures, other applications
exist where the body or parts thereof must be held rigidly or immobile
without discomfort or trauma. E.g., in land, sea, air, or space vehicles,
the head and/or the body must be held securely during positive and
negative accelerations, e.g., when starting, stopping, in case of crashes,
etc.
OBJECTS AND ADVANTAGES
Accordingly several objects and advantages of the invention are to provide
a head immobilizing device which is very comfortable, which is easy to
use, which is simple in operation, which holds the patient's head rigidly,
which does not cause trauma, which does not require surgery, which does
not disfigure the patient, which does not block the patient's breathing,
and which can be used to reposition a patient's head in precisely the same
position as it was previously held by the device. Further objects and
advantages will become apparent from a consideration from the ensuing
description and accompanying drawings.
DRAWING FIGURES
On the first of the two sheets of drawings:
FIG. 1 is a perspective exploded view of a head immobilizing and
positioning device and patient according to the invention.
FIG. 2 is an elevational view of a mouthpiece positioning assembly of FIG.
1;
FIG. 3 is a top view of a level of such assembly; and
FIG. 4 is a cross-sectional view of such assembly in position in a
patient's mouth, taken along the lines 4--4 of FIG. 2.
On the second sheet of drawing:
FIG. 5 is a top view of the head-holding device;
FIG. 6 is a side sectional view of the device taken along the lines 6--6 of
FIG. 5;
FIG. 7 is a back-to-front sectional view taken along the lines 7--7 of FIG.
5; and
FIG. 8 is a front-to-back sectional view taken along the lines 8--8 of FIG.
5.
DRAWING REFERENCE NUMERALS
10 base
12 boss
14 foam ring
16 bottom plate
18 upper portion
20 concave portion
22 hole
24 chamber
25 neck depression
26 neck
28 patient's head
30 broken line
32 suction cup
34 hole
36 apron
38 vacuum coupling
40 T-fitting
42 gauge
44 valve
46 hose
50 mouthpiece
52 positioning gauge
54 teeth
56 holes
58 fingers
60 leg
62 level
64 center pivot
66 thumbscrews
68 baseplate
70 locknuts.
DESCRIPTION OF HEAD-IMMOBILIZING DEVICE
The head-immobilizing device of the invention comprises a head cradle in
which the back of the head rests and to which it is securely held by
actually applying a vacuum to the interior of the cradle to enable ambient
air pressure to press the head thereto in a highly-uniform manner.
As shown in perspective view in FIG. 1, the head-cradling device comprises
a flat base 10, preferably of polystyrene, having a boss or
upwardly-extending cup-shaped portion 12 which is open at the top. The rim
of boss 12 is covered by a cushioning and sealing ring 14 of foam rubber
or the like having a high conformance resolution ability, preferably the
foam sold under the mark TEMPER FOAM by Kee-Gee, Inc. Ring 14 provides at
least a partially-airtight circumferential seal around the back of a
patient's head, as will be described. Base 10 measures about 35 cm by 25
cm overall and boss 12 is about 9.5 cm high. The other dimensions are
scaled approximately as shown in the figures.
Base 10 comprises (FIGS. 6 to 8) a flat, imperforate bottom plate 16 and an
upper portion 18 which is flat around its periphery where it is joined to
the periphery of bottom plate 16, e.g., by solvent cement. Upper portion
18 curves up to form boss 12 and then, after forming a rim under ring 14,
curves down and inwardly to form a concave portion 20. Concave portion 20
has a plurality of holes or perforations such as 22 and extends down to
but does not reach bottom plate 16, as indicated in FIGS. 6 to 8. A
chamber 24 is thereby formed between bottom plate 16 and boss portion 12.
The front part of the rim of the device under ring 14, i.e., the left side
of the rim in FIGS. 1 and 6, curves down to form a neck depression 25;
this depression has a lower height than the rest of the rim so as to
accommodate the neck portion of a patient's head 28 when said patient
places the back of his or her head onto ring 14 and into the device in the
direction indicated by lines 30.
Base 10 is firmly held to a gurney or table (not shown) by any suitable
means, such as four suction cups, e.g., 32, which have upwardly-extending
legs which extend through four corner holes (such as 34) of base 10.
Alternatively, base 10 may be clamped to the table, or it may be bolted,
vacuum held, or even adhesively glued. As a further alternative, base 10
or the entire device may be integrally formed with the table, gurney, or
platform.
Base 10 is generally square in shape, as indicated in the top view of FIG.
5, except for a rectangularly-shaped apron portion 36 which extends back
about 10 cm from the rear edge of base 10 and which also extends partially
under base 10, as indicated in FIG. 6, to rigidify such base. Above apron
36 is a vacuum coupling 38, which is a simple outlet in patent
communication with chamber 24, as indicated in FIG. 6. Coupling 38 may be
integral with boss portion 18, or it may be clamped or bolted thereto. The
free end of coupling 38 is jointed to a "T" fitting 40 which communicates
to a vacuum pressure gauge 42 and to a valve 44 which in turn communicates
to a flexible hose 46. Hose 46 is connected to an adjustable vacuum source
(not shown). Alternatively, parts 38, 40, 42, and 44 may be mounted away
from the head holder, e.g., adjacent the vacuum source (not shown), or
even in another room. The vacuum source should be able to create and
maintain a vacuum of about 7 to 13 cm of Hg.
DESCRIPTION OF POSITIONING DEVICE
The head-immobilizing device aforedescribed will hold a patient's head
rigidly, in the manner to be described infra. However, as noted,
physicians often also have a need to reposition a patient's head in the
same position for multiple diagnostic examinations and treatments over a
period of time. For this purposes the positioning device shown in FIG. 1
and FIGS. 2 to 4 may be used.
The positioning device comprises a mouthpiece 50 and an attachable
positioning gauge 52 which is attachable to mouthpiece 50. Mouthpiece 50
comprises a rigid, but yieldable member, preferably of moldable,
low-molecular-weight polyethylene, which has two grooves which are shaped
to fit between the patient's upper and lower teeth 54, as indicated in
FIG. 4. Mouthpiece 50 also has two rectangular holes 56 in its upper
surface for receiving the bottom fingers 58 of leg 60 of gauge 52.
Gauge 52 comprises a circular fluid-filled level 62 (FIG. 3) having a
conventional air bubble and a centering circle. Level 62 is pivotably
mounted on a center ball-and-socket pivot 64 and its angular orientation
is adjustable by means of three lockable thumbscrews, such as 66, which
are threaded onto a base plate 68 and which have respective locknuts such
as 70. Mounting leg 60 is attached to and extends down from base plate 68,
and, as stated, has two fingers 58 which are shaped to engage and mate
with holes 56 of mouthpiece 50, as indicated in FIG. 4.
OPERATION--HEAD IMMOBILIZING DEVICE
In operation, with the vacuum off, the back of the head of a patient 28 is
positioned onto the head cradle, against faom ring 14, with the patient's
neck 26 in front depression 25 of ring 14, in the manner indicated by
lines 30 of FIG. 1. The patient's head is adjusted to the desired
position, generally facing straight up. Then the vacuum is applied to
chamber 24, either by turning on the vacuum apparatus or by opening valve
44.
When the vacuum reaches the desired level, generally about 10 cm of Hg, in
chamber 24, as indicated by gauge 42, the patient's head will be firmly,
but comfortably held to the device by the pressure differential between
the bottom of the patient's head and the rest of the head, due to the
partial vacuum behind the head from chamber 24 which communicated with the
back of the patient's head via holes 22.
Although the seal between the patient's head and ring 14 will not be
perfect, and hence some air may leak into the device between ring 14 and
the patient's head, I have found that the patient's head will still be
held firmly and in an immobile manner, yet quite comfortably to the
device. The patient's head will be pressed against ring 14 and will not
touch the floor of concave portion 20. Although the patient will not be
able to move his or her head, no trauma or painful force will be sensed by
the patient because the holding force is evenly distributed by the
pressure differential around the relatively large area of ring 14.
Moreover I have found that the device will work quite satisfactorily even
if the patient has long hair.
When the medical procedure is over, the vacuum is released, either by
turning off the vacuum source or opening valve 44. Thereupon the patient's
head will be freed and it can be lifted up and away from the device. No
bruises, pressure marks, or any other adverse effects will result.
OPERATION--POSITIONING DEVICE
If the physician desires to hold the patient in precisely the same position
at a later date, the positioning device of FIGS. 2 to 4 should also be
used to fix the patient's position. Once the patient is in the desired
position, the positioning device is inserted into the patient's mouth and
the patient is instructed to clamp the device between his or her teeth or
gums, as indicated in FIG. 4. When this has been done, mouthpiece 50 will
be fixed to the patient's head in an unambiguous manner.
Then thumbscrews 66 of positioning gauge 52 are adjusted as necessary to
bring the bubble of level 62 into the center circle, whereafter the
thumbscrews are locked in position by their locknuts 70. At this time the
vacuum is actuated to lock the patient's head in position. The positioning
gauge can then be removed, labeled with the patient's name, and stored
until the patient's next visit.
When the patient visits again, the mouthpiece is inserted between the
patient's teeth or gums with gauge 52 attached. The patient's head is
adjusted until the bubble in the level is centered, whereupon the
patient's exact former position will be reached. Then the vacuum is
applied to lock the patient's head in the same position once again. The
process can be repeated as many times as necessary.
SUMMARY, SCOPE, AND RAMIFICATIONS
The reader will thus note that a trauma-free, highly comfortable, simple,
reliable, accurate, and relatively inexpensive means of holding a
patient's head has been provided. A vacuum-holding procedure can be
applied directly to a portion of the person's body without trauma,
discomfort, etc., yet with the ability to create a very rigid securement.
While the above description contains many specificities, these should not
be construed as limitations upon the scope of the invention, but as an
examplification of one preferred embodiment thereof. Many other
embodiments are feasible within its scope. For example, in lieu of holding
a patient's head, a device can be fabricated with a suitable shape to hold
any other portion of a patient's body, such as a torso, leg, arm, etc. The
device can be made of a wide variety of materials in shapes other than as
shown. The positioning device can be attached to a part of a person's
anatomy other than the teeth. Also it can be used with non-human animals.
The device can be used for non-medical procedures, e.g., to hold an
actor's head for the application of makeup, to hold palsied persons for
examination, photography, etc. In lieu of a two-part base, the entire
device can be formed of a single piece of plastic, or the lower part 16 of
the base can be the table and the upper part 18 thereof can be glued to
the table. The vacuum fitting can be attached underneath the device,
rather than at the rear thereof. Accordingly the full scope of the
invention should be determined by the appended claims and their legal
equivalents, and not by the examples given.
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