U.S. patent application number 13/373915 was filed with the patent office on 2012-05-03 for device and method for pupil size modulation.
Invention is credited to Abraham Livne, Ilan Ron.
Application Number | 20120108940 13/373915 |
Document ID | / |
Family ID | 37024228 |
Filed Date | 2012-05-03 |
United States Patent
Application |
20120108940 |
Kind Code |
A1 |
Livne; Abraham ; et
al. |
May 3, 2012 |
Device and method for pupil size modulation
Abstract
A device and method are presented for drug-free, non-invasive,
modulation of a size of a patient's pupil. The invention utilizes
application of an external electric and/or magnetic field of
desired properties to the patient's iris to thereby effect
stimulation or neutralization of synapses and thus temporarily
inducing mydriasis or miosis effect.
Inventors: |
Livne; Abraham; (Kfar Saba,
IL) ; Ron; Ilan; (Kfar Saba, IL) |
Family ID: |
37024228 |
Appl. No.: |
13/373915 |
Filed: |
December 5, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11909103 |
Sep 19, 2007 |
8070688 |
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PCT/IL2006/000362 |
Mar 21, 2006 |
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13373915 |
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Current U.S.
Class: |
600/383 ;
600/558 |
Current CPC
Class: |
A61N 1/36046 20130101;
A61N 2/006 20130101; A61N 1/0543 20130101 |
Class at
Publication: |
600/383 ;
600/558 |
International
Class: |
A61B 5/0496 20060101
A61B005/0496; A61B 3/00 20060101 A61B003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 21, 2005 |
IL |
167559 |
Claims
1-38. (canceled)
39. A medical device for affecting a region of interest in a
patient's body, wherein: the device is configured for drug-free,
non-invasively inducing a desired temporal effect in the region of
interest without actual contact to the region of interest, the
device consists of one or more units configured for operating
externally to the patient's body, said one or more units comprising
an external source of an electric and/or magnetic field which is
configured and operable to produce the electric and/or magnetic
field of desired intensity and direction having a required field
profile in a field region at a certain distance from the external
field source, such that temporal application of said field to the
region of interest causes temporary neutralization or stimulation
of neuron electrical signals at the synapse in the region of
interest, thereby inducing a desired temporal effect of stimulating
or paralyzing muscles within said region of interest by stimulating
or neutralizing their related synapses connections.
40. The device of claim 39, comprising a control unit connected to
the external field source and configured and operable for adjusting
the field profile at a predetermined distance from the external
field source.
41. The device of claim 39, comprising an external sensor for
locating in the vicinity of the field region, the sensor being
configured for measuring intensity of the actual electric and/or
magnetic field, as produced by the external field source, in the
vicinity of the sensor and generating data indicative thereof; and
a control unit configured to be responsive to the data indicative
of the measured field intensity, to process and analyze said data
and upon detecting that adjustment of the field intensity is
required generate a control signal for operating the external field
source.
42. The device of claim 39, wherein said external field source is
configured and operable for providing the field profile for
inducing the effect of temporary modulating a size of the region of
interest with substantially no side effects.
43. The device of claim 39, wherein the external electric and/or
magnetic field source comprises an annular shaped element
presenting an electrode or an electro-magnet unit of the electric
and/or magnetic field source.
44. The device of claim 42, wherein said external field source is
configured and operable for providing the field profile for
affecting a patient's iris for temporary modulating a pupil size
thus inducing mydriasis or miosis effect.
45. The device of claim 44, wherein the external field source
comprises an ocular element configured to be brought close to the
patient's eye and having an electrically insulated surface by which
it faces the patient's eye.
46. The device of claim 39, wherein the external electric field
source comprises an electrode arrangement, and a voltage supply
unit.
47. The device of claim 46, wherein the electrode arrangement
comprises a first electrode not contacting the patient's body, a
direct electric contact to the patient's body serving as a
grounding electrode.
48. The device of claim 46, wherein the electrode arrangement is
formed by first and second electrodes located in a spaced-apart
relationship defining the electric field region between them, and a
voltage supply unit operable to provide a certain potential
difference between the electrodes.
49. The device of claim 46, wherein said external field source is
configured and operable for providing the field profile for
affecting a patient's iris for temporary modulating a pupil size
thus inducing mydriasis or miosis effect, the electrode arrangement
comprising a first ocular electrode configured to be brought close
to the patient's eye and having an electrically insulated surface
by which it is brought to the patient's eye.
50. The device of claim 49, wherein the electrode arrangement
comprises a second grounding electrode configured to be attached
either to a patient's head or to a seat headrest or to a patient's
hand.
51. The device of claim 49, wherein the electrode arrangement
comprises a complementary grounding electrode configured for
connecting it directly to a patient's body.
52. The device of claim 49, wherein the electrode arrangement
comprises a complementary grounding electrode configured to be
isolated or non-isolated.
53. The device of claim 49, wherein the electrode arrangement
comprises an ocular electrode having an annular shape to enable
inspection of the eye via a hole of the ocular electrode.
54. The device of claim 53, wherein said annular-shaped electrode
is configured for mounting a lens in said hole.
55. The device of claim 54, wherein said lens is configured for
being used for retina examination.
56. The device of claim 49, wherein the electrode arrangement
comprises first and second electrodes, each including one or more
electrode elements of respective polarity.
57. The device of claim 49, comprising a hand held or stationary
housing containing the voltage supply unit and the control unit,
the first electrode being located outside said housing and being
connected to the voltage supply unit by an electrically insulated
connector.
58. The device of claim 57, comprising a display located at the
outer surface of the housing to be exposed to user.
59. A hand-held device for use in dilation/contraction of a
patient's pupil, the device comprising: a hand-held housing
containing a voltage supply unit operable to supply voltage to an
electrode located outside said housing and connected to the voltage
supply unit via a connector extending from the housing to said
electrode, the electrode having a substantially annular shape so as
to enable, when brought close to a patient's eye, visual
observation of the eye via an opening defined by the annular-shaped
electrode.
60. A method for drug-free, non-invasive, modulation of a size of a
patient's pupil, by applying an external electric and/or magnetic
field of desired properties to the patient's iris without actual
contact to the patient's eye, to thereby effect stimulation or
neutralization of synapses and thus temporary inducing mydriasis or
miosis effect.
61. A method for drug free, non-invasively, affecting a region of
interest in a patient's body without actual contact to the region
of interest, the method comprising applying to said region of
interest an external electric and/or magnetic field of desired
intensity and direction defining a desired field profile, and
controlling the application of the field, to thereby cause
temporary neutralization or stimulation of neuron electrical
signals at synapse in the region of interest, thereby inducing a
desired temporal effect of stimulating or paralyzing muscles within
said region of interest by stimulating or neutralizing their
related synapses connections.
Description
FIELD OF THE INVENTION
[0001] This invention is generally in the field of medical devices
and relates to a device and method for pupil size modulation
(dilation or contraction).
BACKGROUND OF THE INVENTION
[0002] Every person, irrespective of whether he is healthy or not,
has to at least once undergo an eye examination/treatment that
requires pupil dilation. Those having various eye problems (e.g.,
macular degeneration, diabetes, etc.) require repeated
pupil-dilated eye examinations. The pupil dilation (mydriasis) is
typically induced by application of a dilator drug (typically
atropine) to the patient's eye followed by waiting several minutes
before the pupil is sufficiently dilated to enable the eye
examination.
[0003] Various types of a dilator drug, known as mydriatic agents,
have been developed. For example, WO 98/51292 discloses
pharmaceutical compositions which include a therapeutically
effective amount of a stereoscopically-pure enantiomer, preferably
(+)-phenylephrine is substantially free of (-)-phenylephrine.
[0004] Furthermore, the conventional pupil dilation procedure
results in a recovery period of a few hours, whilst the patient
suffers from excessive light reaching the retina accompanied by
focusing difficulties. Moreover in this recovery period, it is
highly recommended that the patient will refrain from driving or
doing dangerous tasks.
[0005] Constriction of a pupil size (miosis) is required for
individuals suffering from excessive pupillary dilation, e.g., in
dim light or through medication. Various drug-based treatments
suitable to be used for this purpose are disclosed for example in
the following patents: U.S. Pat. No. 6,730,065; U.S. Pat. No.
6,515,006; U.S. Pat. No. 6,420,407; U.S. Pat. No. 6,291,498.
[0006] It is known to use the principles of electrophoresis to
assist the drug delivery process (e.g., deliver of vitamins, such
as Vitamin C). Electrophoresis is an electrochemical process in
which colloidal particles or molecules with a net electric charge
migrate in a solution under the influence of an electric current.
This process is also termed "iontophoresis" or "cataphoresis".
[0007] U.S. Pat. No. 6,101,411 discloses a dilation enhancer
apparatus, which is a hand held electrophoretic device using a
contact lens type delivery system to provide rapid clinically
useful dilation of the pupil of the eye. The apparatus includes a
contact lens with a conductive outer shell (one electrode of a
two-electrode electrophoresis device) and a preferably soft,
preferably disposable contact lens for contacting a patient's eye
that assists in delivering dilation drops or other medicaments to a
patient's eye. Advantageously, the lens is used with a relatively
small hand-held power source. Electrophoresis can be used to help
deliver dilation drops more rapidly, regardless of the delivery
apparatus used for the electrophoresis.
SUMMARY OF THE INVENTION
[0008] There is a need in the art to facilitate the pupil
dilation/constriction process by providing a novel device and
method for quickly and effectively inducing a temporarily pupil
dilation (mydriasis) or contraction (miosis) without a need for eye
drops, and with rapid recovery.
[0009] The present invention is based on the understanding of the
effects of neuron electrical signals propagation at the synapse, or
any other part of the nervous system, associated with the pupil
control muscles. Electrical signals are propagated through the
synaptic cleft, using neurotransmitters. A Neurotransmitter is a
substance synthesized in neurons (nerve cells) and released across
the synaptic cleft (a space between neurons) in response to an
action potential. A Neurotransmitter or the so-called "chemical
messenger" thus presents a chemical signal carrying an electrical
impulse passing through a human body.
[0010] The technique of the present invention provides for
controllably affecting the action potential (to which the
neurotransmitter is responsive) by applying an external electric
and/or magnetic field, aimed at either neutralizing or enhancing
this action potential. Alternatively, the technique of the present
invention provides for controllably inhibiting neurotransmitters
from reaching their destination (receptors) by applying an external
electric and/or magnetic field in opposite or diverting directions
other than the neurotransmitters path.
[0011] The most important function of the iris is to control the
pupil size. The iris muscles regulate the pupil size and thus
control the amount of light that can enter the pupil and fall on
the retina. The pupil size is controlled by two sets of internal
iris muscles: radial (dilator) muscles that allow pupil expansion,
and circular muscles that allow pupil contraction.
[0012] The technique of the present invention provides for
controllably stimulating or paralyzing the respective muscles of
iris by either neutralizing or stimulating their related synapses
connections. Mydriasis can be reached by either paralyzing the
circular muscles and/or stimulating the radial muscles, and
miosis--vice versa. When both the circular and radial muscles are
paralyzed or do not receive any stimulus, the basic tonus of the
dilator (radial) muscles overcomes the tonus of the circular
muscles, and the pupil is dilated, thus Mydriasis can also be
obtained.
[0013] Alternatively, the technique of the present invention
provides for obtaining the Mydriasis effect by differentially
applying an electric field to affect the contractor muscles more
than the dilator muscles. The differential effect can be achieved
by applying the field in a direction, which is perpendicular to the
contractor muscles and parallel to the dilator muscles, so that the
field would inhibit the action potential, and/or movement of
charged particles, in the contractor muscle more than in the
dilator muscle. Alternatively, since the dilator muscles are more
interior to the contractor muscles, the electric field would pass
through the human tissue before reaching the dilator muscles, and
would thus be attenuated significantly. This reduces its effect on
the dilator muscles, so that it is smaller than the effect on the
contractor muscles.
[0014] The present invention thus provides a drug-free,
non-invasive modulation of a pupil size (dilation/contraction of
the pupil), by temporarily inducing the mydriasis or miosis effect,
by means of subjecting the iris to an external electric and/or
magnetic field of desired properties (direction and intensity). The
field effects stimulation or neutralization of the iris muscles
synapses.
[0015] According to one embodiment of the invention, depolarization
is applied to the iris through an electric field of negative
polarity. This may cause the synapses stimulation by enhancing the
action potential. According to another embodiment, repolarization
is applied through an electric field of positive polarity, thus
achieving synapses neutralization by reducing the action potential.
According to yet another embodiment of the invention, an external
field is applied so as to deflect or divert the neurotransmitters
from their original direction of propagation, thus inhibiting
neurotransmitters to pass through the synapses and preventing them
from reaching their respective receptors. Hence, the synapses
neutralization can be achieved by applying an electric field in
either opposite or substantially orthogonal direction to the
neurotransmitters original direction of propagation in the
body.
[0016] The resulting recovery time is measured in seconds, thus
eliminating or at least substantially reducing the associated
lingering side-effects of commonly used Mydriasis inducing
methods.
[0017] According to yet another embodiment of the invention, the
iris is subjected to an external magnetic field directed
substantially perpendicular to the neurotransmitters path, using
the principles of the known Van Allen radiation belts' effect. In
the Van Allen belts, charged particles are trapped in the Earth's
magnetic field. A force on the charged particles is normal to the
magnetic field lines. These highly energetic charged particles
actually move in helical paths around the magnetic field lines. As
the charged particles move closer to the earth's magnetic poles,
the force increases until the particle can no longer move any
farther forward and gets repelled back down to repeat the process
with the opposite pole.
[0018] The present invention provides for any drug free,
non-invasive, temporary neutralization or stimulation of neuron
electrical signals at the synapse, or any other part of the nervous
system, associated with the pupil control muscles. Such effects
include, but are not limited to, local anesthetic, tension relief,
etc.
[0019] Thus, according to one broad aspect of the present
invention, there is provided a device for modulation of a pupil
size, the device comprising a source of electric and/or magnetic
field configured and operable for creating said field(s) of desired
properties in a region of a patient's eye to thereby effect
stimulation or neutralization of synapses or any other part of the
nervous system, associated with the pupil control muscles, and thus
temporarily induce mydriasis or miosis effect, the device thereby
providing a drug-free modulation of a pupil size.
[0020] The device may be of a simple configuration including only a
source of the external electric and/or magnetic field. The field
source is configured and operable to define a field region where
the patient's eye is to be located and create the external field of
required intensity and direction in the field region.
[0021] The device may also include a field sensor and a control
unit. The sensor is located in the vicinity of the field region and
is configured for measuring the actual field intensity and
generating feedback data indicative thereof. The control unit is
configured to be responsive to required field intensity settings
and the feedback data indicative of the measured field intensity
for processing and analyzing this data, and upon detecting that
adjustment of the field intensity is required, generating a
respective control signal to the field source unit. Alternatively
the operator can adjust the voltage and/or current level(s)
according to noticeable effect, thus dismiss the use of the sensor
and the associated control loop.
[0022] The external electric field source includes a voltage supply
unit, and defines an electrode arrangement, a potential difference
between the electrodes defining a field region. Such an electrode
arrangement may be defined by one of the following options: the
device may include at least one pair of electrodes, one being an
"ocular" electrode and the other being a "complementary" electrode;
or the device may include only the ocular electrode while the
complementary end of the circuit is constituted by direct contact
to patient's body. The electric field between the electrodes is
thus of a substantially constant profile.
[0023] The first electrode, termed "Ocular electrode", is
preferably configured to be brought close to the patient's eye, and
has an electrically insulated surface by which it is brought to the
proximity of the patient's eye. The second electrode, termed
"Complementary electrode", is configured to be situated in a
position to facilitate for an electric field region where the
patient's eye is to be located. This electrode may be attached
either to the patient's head or to a seat headrest, or any other
means of mounting it in the required position, or may be
constituted by direct contact to the patient's body. The second,
complementary electrode may be carried by a head band to be put on
the patient's head. The field sensor may be attached to this head
band.
[0024] If the application of the external magnetic field is
considered, the magnetic field source includes an electro-magnet
unit (such as a coil unit or superconductor arrangement) serving as
an ocular element; and a power (current) supply unit.
[0025] The ocular element (electrode or electro-magnet unit)
preferably has an annular shape to enable inspection of the eye via
a hole of the ocular element. The annular-shaped ocular element is
preferably configured for mounting a lens in the electrode
hole.
[0026] The device may be designed as a hand held probe, or as a
probe for mounting it on the slit lamp table. Such a probe device
contains the voltage/current supply unit (and possibly also the
control unit), where the ocular element (electrode or
electro-magnet unit) is located outside the probe housing and is
connected to the voltage/current supply unit by an electrically
insulated connector. Preferably, a display may be located at the
outer surface of the housing to be exposed to the user. Also, the
complementary electrode can reside on the held hand device.
[0027] According to another broad aspect of the present invention,
there is provided a device for use in dilation/contraction of a
patient's pupil, the device comprising: a source of an external
electric and/or magnetic field configured and operable to define a
field region where the patient's eye is to be located and create
the external field of required properties in said field region to
thereby temporarily induce an effect of mydriasis or miosis; a
sensor located in the vicinity of said field region and configured
for measuring the actual field intensity and generating data
indicative thereof; and a control unit configured to be responsive
to the data indicative of the measured field intensity to process
and analyze said data and upon detecting that adjustment of the
field value is required generate a feedback signal to a voltage
supply unit of the field source.
[0028] According to yet another aspect of the invention, there is
provided a device for use in dilation/contraction of a patient's
pupil, the device comprising: a housing containing a voltage supply
unit operable to supply voltage to an electrode located outside
said housing and connected to the voltage supply unit via a
connector extending from the housing to said electrode, the
electrode having a substantially annular shape so as to enable,
when brought close to a patient's eye, visual observation of the
eye via an opening defined by the annular-shaped electrode.
[0029] According to yet another broad aspect of the invention,
there is provided a device for use in dilation/contraction of a
patient's pupil, the device comprising: a housing containing a
current supply unit operable to apply current to an electro-magnet
unit located outside said housing and connected to the current
supply unit via a connector extending from the housing to said
electro-magnet unit, the electro-magnet unit having a substantially
annular shape so as to enable, when brought close to a patient's
eye, visual observation of the eye via an opening defined by the
annular-shaped electro-magnet unit.
[0030] The housing may be configured to be held by user, or to be
mounted on a slit lamp table.
[0031] According to yet another broad aspect of the invention,
there is provided a method for drug-free modulation of the size of
a patient's pupil, by applying an external electric and/or magnetic
field of desired properties to the patient's iris to thereby effect
stimulation or neutralization of synapses and thus temporarily
inducing mydriasis or the miosis effect.
[0032] According to yet another aspect of the invention, there is
provided a method for a drug free, non-invasive, temporary
neutralization or stimulation of neuron electrical signals at the
synapse, or any other part of the nervous system, associated with
the pupil control muscles in a region of interest of a human body,
the method comprising applying an external electric and/or magnetic
fields to the region of interest.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] In order to understand the invention and to see how it may
be carried out in practice, preferred embodiments will now be
described, by way of non-limiting examples only, with reference to
the accompanying drawings, in which:
[0034] FIGS. 1A and 1B are schematic illustrations of an example of
a device of the present invention for appropriately modulating the
pupil size, utilizing an electric field source;
[0035] FIGS. 2A to 2C exemplify the specific implementation of the
device of FIGS. 1A-1B;
[0036] FIG. 3 is a schematic illustration of another example of a
device of the present invention, utilizing a magnetic field
source;
[0037] FIGS. 4A to 4C exemplify the specific implementation of the
device of FIG. 3; and
[0038] FIG. 5 is a flow diagram of a method of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0039] The present invention provides for a drug-free modulation of
a pupil size (dilation/contraction of the pupil), by effecting
stimulation or neutralization of the synapses by subjecting the
patient's iris to an external electric and/or magnetic field of
desired properties (direction and intensity).
[0040] Referring to FIGS. 1A and 1B, there is schematically
illustrated an example of a device 10 of the present invention for
use in modulating (dilating/contracting) the pupil size of a
patient P. The device 10 includes a source 12 of an external
electric and/or magnetic field, associated with a power source
(preferably a battery pack or adapter input plug) which is not
specifically shown here.
[0041] Field source 12 is configured and operable to create a DC
electric field of a required profile within a field region FR. The
field profile defines a required field value within a patient's eye
(iris) location L in the field region. By this, an effect of
mydriasis or miosis of the iris (depending of the field value) is
temporary induced, namely during the application of said field.
[0042] In the present example, an electric field is considered.
Electric field lines B are shown in FIG. 1B. The electric field
source 12 includes an electrode arrangement 12A and a voltage
supply unit 12B.
[0043] The electrode arrangement 12A of the device 10 includes two
electrodes E.sub.1 and E.sub.2 kept at a required potential
difference between them. The electrodes are accommodated in a
spaced-apart relationship to be at opposite sides of the patient's
head such that the field lines B mostly pass through the iris
location L. One electrode E.sub.1 is preferably configured to be
brought close to the patient's eye and is termed "ocular element"
or "ocular electrode", and the other electrode E.sub.2, termed
"complementary electrode", may be either attached to a patient's
chair (seat head rest) so as to be close to the patient's head or
carried by a band F to be put onto the patient's head (as shown in
FIG. 1A).
[0044] It should be noted, that according to the invention the
ocular electrode E.sub.1 is fully insulated, in order to prevent
electrocution hazard. The complementary electrode E.sub.2 may also
be completely insulated or may be grounded. The complementary
electrode presents a complementary part of the electric field
lines, to ensure that some field lines pass through the pupil area.
If the use of a conductive insulated element in a complementary
electrode is considered, such an element may be attached to the
patient's body, and the patient's body thus becomes the
complementary electrode. The electric potential is thus equalized
in the body. It should be understood that no electric current flows
between the electrodes, since the ocular electrode is still fully
insulated. In a similar manner, both the complementary electrode
and the patient's body may have a conductive path to the
ground.
[0045] The ocular electrode E.sub.1 is preferably of an annular
shape defining a hole large enough to enable visual inspection of
the eye via the enlarged pupil. The ocular electrode hole may be
used for combining lenses commonly used by eye physicians for
retina examination, such as slit lamp using 78D and 90D lenses; or
indirect ophthalmoscope using a 20D lens.
[0046] The electric field profile within the field region FR and
accordingly the field intensity at the iris location L within this
region is defined mainly by a potential difference between the
electrodes E.sub.1 and E.sub.2 and a distance between the
electrodes. The electric field between two electrodes inhibits
nervous impulses to iris muscles. It should be noted that the
voltage polarity can be of either type.
[0047] In order to desirably affect the pupil size (e.g., achieve a
mydriasis effect), a minimal field intensity level should be
created at the iris location L. This field intensity depends mainly
on the following factors: the applied voltage, distance and
attitude of each electrode with respect to the iris, and dielectric
characteristics of the specific patient.
[0048] Preferably, the device 10 utilizes a closed-loop control
circuit 18. The latter is formed by a field sensor 14 located
within the field region FR and configured and operable for
measuring the actual field intensity value and generating data
indicative thereof; a control unit 16 connectable to field source
12 and field sensor 14, and the voltage supply unit 12B. Thus, the
required field intensity at location L is set by user (operator)
and controlled using a feedback signal of the control unit 16 based
on data measured by the field sensor 14. Alternatively, the
operator can adjust the voltage level according to noticeable
effect, thus eliminating the need for the control loop (sensor and
control unit).
[0049] The device of the present invention thus provides for
affecting synaptic transmission to desirably modulate the pupil
size. This is implemented either by contradicting the natural
action potential by applying the parallel field; or by inhibiting
neurotransmitters arrival to receptors by diverting them from their
course using an orthogonal field, as will be described below.
[0050] The electric field sensor 14 may have any known suitable
configuration, for example a flux meter, an electro-optic detector
for example of the type based on an optical Fabry-Perot sensing
cavity. The voltage supply unit 12B is a high voltage DC circuit
generating the required potential difference (e.g., about 80-200V)
between the electrodes.
[0051] The control unit 16 is typically a computer system,
including inter alia a memory utility 16A for storing certain
reference data (e.g., calibration data), a processor 16B, user
interface utility 16C (e.g., display). The control unit 16 operates
for maintaining the required field intensity (in response to the
data coming from the field sensor 14) and supervising the device.
The control unit 16 receives measured data MD indicative of the
measured field value, processes and analyzes this data and operates
the field source (voltage supply unit 12B) accordingly when
adjustment of the field source operation is required to provide the
desired field intensity value in the region of interest. To this
end, the control unit 16 is appropriately preprogrammed to set the
field value level either in a digital format or as an explicit
voltage level, and to generate a field intensity control signal
S.sub.fb to operate the voltage supply unit 12B. The control unit
16 may display the set value and the device status.
[0052] Reference is made to FIGS. 2A-2C showing a specific but not
limiting example of the implementation of the present invention. As
shown in FIG. 2A, a device 100 includes an external field source 12
(electric field source in the present example), a field sensor 14,
and a control unit 16. The electric field source 12 includes an
electrode arrangement 12A and a voltage supply unit 12B. The
electrode arrangement 12A includes an annular ocular electrode
E.sub.1 connected to voltage supply unit 12B via a conductor grip
15, and a second complementary electrode E.sub.2 to be attached to
a seat headrest or a head-band. A lens may be located within the
hole of the ocular electrode E.sub.1. The electrodes E.sub.1 and
E.sub.2 are electrically connected to the voltage supply unit 12B
(DC2DC circuit) to be supplied with different voltages defining a
desired potential difference between them. The control unit 16 is
interconnected (via wires or wireless) between voltage supply unit
12B and field sensor 14. Voltage supply unit 12B and control unit
16 are connected to a power source (battery pack) 20.
[0053] As shown in FIG. 2B, the device has a hand held probe 22
containing the voltage supply unit and preferably the control unit
(which are not shown here) with a display 16C being exposed to
user, and the annular-shaped ocular electrode E.sub.1 is located
outside the probe 22 being connected to the voltage supply unit via
an insulated wire connector 24 (preferably sufficiently flexible
connector). A lens 26 is optionally provided in the ocular
electrode hole, such that the electrode E.sub.1 serves as the lens
carrier. The electrode E.sub.1 may be optically transparent. The
device 100 allows a hand held free operation as is performed by
physicians when examining the retina. The second electrode E.sub.2
is located as described above and a voltage supply thereto may or
may not be controlled (e.g., the device operation can be controlled
only by controlling the voltage supply to the ocular electrode
E.sub.1).
[0054] Alternatively, the use of a second electrode E.sub.2 can be
replaced by a direct electrical contact with the patient's head or
body, thus using it as the complementary end of the electrical
field. If such an option is applied, it is also advised that this
electrode is grounded, in order to prevent electrocution
hazard.
[0055] As shown in FIG. 2C, in the present example, the field
sensor 14 is mounted on the complementary electrode E.sub.2. The
lens 26 (the provision of which is optional) is inserted into the
hole of electrically insulated ocular electrode E.sub.1. The
electrodes E.sub.1 and E.sub.2 are connected (by wires) to the
voltage supply unit (DC2DC high voltage converter) located inside
the housing 22. The field sensor 14 is connected (by wires or
wireless) to the field control and field intensity setting circuit
of the control unit located inside the housing 22. Considering the
indirect ophthalmoscope configuration of the device, the probe 22
to be held by a physician also carries a light source 30 (e.g.,
LED).
[0056] Reference is made to FIGS. 3 and 4A-4C exemplifying a device
200 of the present invention utilizing application of a magnetic
field to the patient's eye. In the case of a magnetic field
application, the magnetic field source can include a permanent
magnet or coils or any form of a magnetic field generator.
Furthermore, both the electric and magnetic fields may be
applied.
[0057] The device 200 includes a magnetic field source 212 formed
by an electro-magnet unit (e.g., coil unit) 212A and a power supply
unit (current supply unit) 212B. A control unit 16 is connected to
the current supply unit 212B and to a magnetic field sensor 214
appropriately configured and accommodated for measuring the actual
field value in the region of interest. Field source 212 is
configured and operable to create a DC external magnetic field of a
required profile within a field region FR. The field profile
defines a required field value within a patient's eye (iris)
location L in the field region. By this, an effect of mydriasis of
the iris is temporary induced. Magnetic field lines are shown in
FIG. 3.
[0058] The control 16 is configured and operable to modify the
applied current through the coil 212A according to the feedback
obtained from the field sensor 214 and applied settings (instead of
controlled voltage in the case of electric field application). In
the case of a magnetic field application, a single coil unit may
for example be used.
[0059] The coil unit 212A is accommodated in the vicinity of
patient's eye such that the field lines B mostly pass through the
iris location L. The coil unit 212A may be of an annular shape
defining a hole large enough to enable visual inspection of the eye
via the enlarged pupil. Such an ocular hole may be used for
combining lenses commonly used by eye physicians for retina
examination or indirect ophthalmoscope, as described above. It
should be understood that generally, the ocular element may be
formed by one or more magnetic elements, one of them having an
annular shape to allow eye examination therethrough.
[0060] The magnetic field profile within the field region FR and
accordingly the field intensity at the iris location L within this
region is defined mainly by a field intensity at the coil unit 212A
and a distance from the iris. This magnetic field inhibits nervous
impulses to iris muscles. It should be noted that the magnetic
field polarity could be of either type.
[0061] Similar to the electric field case, in order to desirably
affect the pupil size (e.g., achieve a mydriasis effect), a minimal
magnetic field intensity level should be present at the iris
location L. This field intensity depends mainly on the applied
current through the coil, distance and attitude of the coil with
respect to the iris, and magnetic characteristics of the specific
patient. To this end, the device 200 utilizes a closed-loop control
circuit. The latter is formed by the field sensor 214 located
within the field region FR and configured and operable for
measuring the actual field intensity value and generating data
indicative thereof; the control unit 16 and the current supply unit
212B. The required field intensity at location L is set by user and
controlled using a feedback signal of the control unit 16 based on
data measured by the field sensor 214. The field sensor 214 may
have any known suitable configuration, for example based on
employing the magnetoresistive effect of thin-film perm-alloy. The
current supply unit 212B is a high DC current source circuit
generating the required currents to the coil unit.
[0062] Thus, in the case of magnetic field, the device of the
present invention provides for affecting synaptic transmission to
desirable modulate the pupil size by inhibiting neurotransmitters
arrival to receptors by diverting them from their course using an
orthogonal field.
[0063] FIGS. 4A-4C show a specific, but not limiting, example of
the implementation of the device of FIG. 3. As shown in FIG. 4A,
the device 200 includes an external magnetic field source 212, a
magnetic field sensor 214, and a control unit 16. The magnetic
field source 212 includes a coil unit 212A and a current supply
unit 212B. The coil unit 212A includes an annular ocular coil
connected to current supply unit 212B (controllable DC current
source) via a conductor grip 15, to be therefore supplied with
different currents defining a desired magnetic field intensity in
the region of interest. A lens may be located within the hole of
the ocular coil. The control unit 16 is interconnected (via wires
or wireless) between the current supply unit 212B and field sensor
214. Current supply unit 212B and control unit 16 are connected to
a power source 20.
[0064] As shown in FIG. 4B, the device has a hand held probe 22
containing the current supply unit and the control unit (which are
not shown here) with a display 16C being exposed to user, and the
annular-shaped ocular coil 212A is located outside the probe 22
being connected to the current supply unit via an insulated wire
connector 24 (preferably sufficiently flexible connector). A lens
26 is optionally provided in the ocular coil hole, such that the
coil serves as the lens carrier. The coil may be optically
transparent. The device 200 allows a hand held free operation as is
performed by physicians when examining the retina.
[0065] As shown in FIG. 4C, in the present example, the field
sensor 214 is mounted on the head band. The lens 26 (the provision
of which is optional) is inserted into the hole of electrically
insulated ocular coil 212A. The latter is connected (by wires) to
the current supply unit located inside the housing 22. The field
sensor 214 is connected (by wires or wireless) to the field control
and field intensity setting circuit of the control unit located
inside the housing 22. Considering the indirect ophthalmoscope
configuration of the device, the probe 22 to be held by a physician
also carries a light source 30 (e.g., LED).
[0066] FIG. 5 shows the flow diagram of a method of the present
invention. The patient is positioned such that his eye is at a
desired location within an expected field region. The external
field (electric and/or magnetic) is created in this region (by
bringing the ocular element, electrode and/or coil, close to the
patient's eye, and in the case of electric field possibly also
appropriately arranging the rear complementary electrode). The
control unit operates the field source to measure the actual field
value in the vicinity of the patient's eye, and if needed operates
the voltage and/or current supply unit to readjust the field
intensity, thereby causing the pupil size modulation and allowing
eye inspection via the enlarged pupil.
[0067] The following are the results of experiments conducted by
the inventors. In these experiments, the electric field application
was used.
[0068] Table I presents the experimental data for the first set of
experiments. An experimental set up used in these experiments
included a disk-shaped ocular electrode and a field generating DC
voltage of 99.8V. Two methods were used: proximity of the active
ocular electrode to the iris; and ON/OFF power application whereas
no effects are eminent when power is OFF, and the pupil reacts to
illumination changes as usual. Direct illumination of the examined
eye was applied in both cases; turning the illumination ON and OFF
during the device operation did not affect the pupil size. The
results were in the form of a pupil diameter, and were obtained
using standard ophthalmic measurement equipment including
magnifying lenses. Two parameters were controlled to estimate their
effect on the measurements: voltage polarity (positive polarity
being connected to the ocular electrode); and the complementary
electrode position (head rest, or near the temple).
[0069] In these experiments, the actual distance between the ocular
electrode and the eye was not fixed from one test to the other, and
no feedback mechanism was used, thus the resulting effect varies
due to the hand held proximity variance. It should be understood
that the required field effect uniformity could be achieved by
using the feedback and control mechanism. These experiments just
demonstrate the actual pupil size modulation effect. Each test
included precise measurements of the subject's pupil diameter,
using standard ophthalmic measurement equipment with accuracy of
0.05 mm. Pupil diameter measurements were performed at the
beginning of each test and under the operation of a device of the
present invention (configured for the application of electric
field), and showed an increase in pupil diameter accordingly. In
these tests, a probe carrying an annular-shaped ocular electrode
was brought to the patient's eye to position the ocular electrode
to maximal proximity of the eye, without actual contact (in the
vicinity of the eye lashes). A complementary electrode (the
provision of which is optional) was configured as a plate (in an
insulating cover) and located aside the patient's head. In order to
perform a full retina inspection, a minimal pupil diameter of 4 mm
is required, which was achieved in the experiments. Furthermore,
voltage level can be increased to cater for a stronger pupil size
modulation effect and a larger position space of the ocular
electrode. Tested variants included lighting intensity (upon which
initial pupil diameter reacted); complementary electrode
connection; one idle operation (no voltage applied). Test results
where recorded on both video and photographs. The tests were
performed using 99.8 DCV applied between the ocular electrode and
the complementary electrode, where the ocular electrode was
connected to the negative pole. The ocular electrode consisted of a
conductive washer-like ring, coated with isolative material and was
carried by an isolated handle. Each test included two measurements:
initial measurement (with no electric field application) and
measurement upon applying the electric field.
TABLE-US-00001 TABLE I Light Complementary Initial Modulated
intensity electrode pupil pupil Record Test level
position/connection Voltage diameter diameter type 1 1 Isolated
near temple 99.8 VDC 2.7 mm 3.5 mm Photo 2 2 Isolated near temple
99.8 VDC 2.3 mm 4.1 mm Photo 3 1 Isolated near temple 99.8 VDC 2.5
mm 3.9 mm Video 4 1 Isolated near temple 0 VDC 2.6 mm 2.6 mm Video
5 1 Positive pole 99.8 VDC 2.6 mm 3.4 mm Video conductive,
connected to subject's chin & earthed
[0070] Table II presents further experimental data obtained with
the device configuration for the electric field application to the
patient's eye. The device included a round, washer-like plate-like
ocular electrode. The latter was placed at a 5 mm distance to the
patient's eye. The second, complementary electrode was in the form
of a rectangular plate located near temple. The experiments were
carried out under room dimmed light with different voltage values
(i.e. a potential difference between the two electrodes):
TABLE-US-00002 TABLE II Modulated pupil Test Illumination Voltage
L.sub.ref L.sub.mea diameter 1 Room 30 V 22.34 20.396 4.6 dimmed
light 2 Room 40 V 22.34 20.396 4.6 dimmed light 3 Room 50 V 22.34
20.03 4.5 dimmed light
[0071] In these experiments, the measurement method includes
analysis of photographs, taken of the examined eye, and calculation
of the pupil size according to the ratio between the L.sub.mea
(measured pupil diameter from the picture) and L.sub.ref (a scale
of 5 mm notches, photographed in the measurement picture).
[0072] Table III shows yet further experimental data obtained with
the ocular electrode of an ice cream scrapper shape and the
complementary electrode in the form of a side plate near the
temple, under room light. In this Table, tests 1-3 and 4 correspond
to tests carried out on two different patients, respectively: test
1 data corresponds to the initial state of the patient's eye, i.e.
with no application of external field; tests 2 and 3 data
correspond to said eye under the application of an electric field
by applying different voltages (potential difference between the
electrodes), and test 4 data corresponds to the experimental
results for the second patient. In these experiments, a ratio
between the pupil and iris is calculated (whereas the iris size
does not change and serves as a constant reference).
TABLE-US-00003 TABLE III Expansion Estimated Test Illumination
Voltage Iris/pupil ratio ratio pupil size 1 Room light Not 71/22.3
= 3.18 9/3.18 = 2.8 mm applied 2 Room light 60 V 72/31.9 = 2.26
3.18/2.26 = 1.4 9/2.36 = 4 mm 3 Room light 70 V 60.6/29.5 = 2.05
3.18/2.05 = 1.55 9/2.05 = 4.4 mm 4 Room light 70 V 53.5/24.0 = 2.23
3.18/2.23 = 1.52 9/2.23 = 4.1 mm
[0073] Thus, the present invention provides a simple and effective,
drug-free temporary modulation of a pupil size
(dilation/contraction of the pupil), by effecting stimulation or
neutralization of the synapses by subjecting the iris to an
external electric and/or magnetic field of desired properties
(direction and intensity)
[0074] Those skilled in the art to which the present invention
pertains can appreciate that while the present invention has been
described in terms of preferred embodiments, the concept upon which
this disclosure is based may readily be utilized as a basis for the
designing of other structures, systems and processes for carrying
out the several purposes of the present invention.
[0075] Also, it is to be understood that the phraseology and
terminology employed herein are for the purpose of description and
should not be regarded as limiting.
[0076] It is important, therefore, that the scope of the invention
is not construed as being limited by the illustrative embodiments
set forth herein. Other variations are possible within the scope of
the present invention as defined in the appended claims and their
equivalents.
* * * * *