Title of Invention

AN ELECTRODE ARRAY ASSEMBLY AND A METHOD OF CONTROLLING INTER-ELECTRODE RESISTIVITY IN SUCH ARRAY FOR MEASURING ELECTRICAL ACTIVITY IN A BIOLOGICAL TISSUE

Abstract There is disclosed an electrode array assembly comprising an electrode support (10); a group of electrodes (23) mounted on the electrode support (10) for measuring electrical activity in a subject's biological tissue; and an inter-electrode conductive medium; wherein the inter-electrode conductive medium has a given resistivity and is applied to the electrodes (23) of the group and the electrode support (10) between the electrodes for controlling, during electrical activity measurement, resistivity between the electrodes (23) of the group to improve said electrical activity measurement and wherein, when electrical contact between at least one electrode (23) of the group and the subject's biological tissue is poor, the inter-electrode conductive medium forms a means for producing on said at least one electrode an estimate of the electrical activity in the subject's biological tissue, said estimate being a mean value of electrical potentials produced on neighbouring electrodes of the group by the electrical activity in the subject's biological tissue
Full Text AN ELECTRODE ARRAY ASSEMBLY AND A METHOD OF CONTROLLING INTER-
ELECTRODE RESISTIVITY IN SUCH ARRAY FOR MEASURING ELECTRICAL
ACTIVITY IN A BIOLOGICAL TISSUE
FIELD OF THE INVENTION
The present invention relates to a method for controlling inter-electrode
resistivity and to an electrode array having an inter-electrode resistivity
controlled by this method.
BACKGROUND OF THE INVENTION
The current technology uses electrodes to measure electrical activity in a
subject's biological tissue, e.g. muscles. Each electrode is either bare or
individually covered with a conductive medium while the highest possible
resistivity is maintained between the electrodes.
The use of an electrode array to measure electrical signals from, for
example, a muscle requires that at least one signal electrode and a reference
electrode be in contact with the subject's biological tissue via an electrically
conducting medium to produce a defined muscle-related electric potential. If an
electrode is in a poor electrically conducting medium, e.g. loses contact with the
biological tissue and is isolated in air, it will deliver a non defined electric
potential dominated by capacitive disturbances; the electrode will then act similar
to an antenna. An electrically conducting medium can comprise any electrolyte
or conductive substance/material. Such a non defined electric potential can still
present an amplitude higher than the common noise level and can be mistakenly
inctaded in the signal processing as a valid signal representative of the electrical
activity of the subject's muscle.
A poor electrically conducting medium or the absence of electrically
conducting medium between one electrode of an an"ay and the subject's
biological tissue will cause a loss of the balancing "half-cell potential" and
change the electrode potential relative to the electric potentials on the other
electrodes of the array that have maintained contact with the biological tissue;
more specifically, the DC potential will be altered. Also, the loss of contact of one
electrode with the biological tissue increases the electrode impedance and also
makes the electrode more sensitive to capacitively-induced disturbances.
Consequently, the electric potentials on the various electrodes of the an"ay will
be different depending on whether these electrodes maintain or not contact with
the subject's biological tissue. Accurate measurements require either removal of
the DC component or removal of the channels with DC offset. Offset problems
affect primarily the first amplification stage, which has to produce limited gain in
case of large DC levels.
Recently, the feasibility of improving signal quality by covering an
electrode array for measuring electrical activity in a subject's biological tissue
with a mesh/matrix was demonstrated.
However, no method/technology is known or currently used to control the
inter-electrode resistivity of an electrode array for the purpose of improving
quality of the measured signals related to electrical activity of a subject's
biological tissue. Control of the inter-electrode resistivity of an electrode an-ay
results in improvement of the signal quality by eliminating artifactual
influences/disturbances due to poor electrode-to-tissue contact.
SUMMARY OF THE INVENTION
According to the invention, there is provided a method of controlling an
inter-electrode resistivity in an electrode array including a group of electrodes for
measuring electrical activity in a subject's biological tissue, comprising providing
an inter-electrode conductive medium having a given resistivity between the
electrodes of the group, and interconnecting the eiectrodes of tine group through
this Inter-electrode conductive medium to thereby control resistivity between the
electrodes.
The present invention also relates to an electrode array for measuring
electrical activity in a subject's biological tissue, comprising:
an electrode support;
a group of electrodes mounted on the electrode support; and
an inter-electrode, conductive medium liaving a given resistivity for
controlling resistivity between the electrodes of the group.
Further in accordance with the present invention, there is provided an
electrode array for measuring electrical activity in a subject's biological tissue,
comprising:
a catheter with a distal end section;
a series of electrodes mounted on the distal end section of the catheter;
and
an inter-electrode conductive medium having a given resistivity for
controlling resistivity between the electrodes of the series.
In this manner, when contact between at least one electrode of the group
and the subject's biological tissue is poor, an estimate of the electrical activity in
the subject's biological tissue is produced on this electrode through the Inter-
electrode conductive medium. This estimate is constituted by a mean value of
electrical potentials produced on neighbouring eiectrodes of the group by the
electrical activity in the subject's biological tissue.
According to a non-restrictive illustrative embodiment, the inter-electrode
conductive medium between the electrodes may include a reference electrode.
The foregoing and other objects, advantages and features of the present
invention wih become more apparent upon reading of the foliowing non-
restrictive description of an illustrative embodiment thereof, given by way of
example only with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
In the appended drawings:
Figure 1 is a cross sectional view of a catheter fomhng part of an
Illustrative embodiment of the electrode an'ay according to the present invention,
this cross sectional view being talcen along line 1-1 of Figure 3;
Figure 2 is a side eievational view of a proximal end section of the
catheter of Figure 1;
Figure 3 is a side eievational view of a distal, free end section of the
catheter of Figures 1 and 2, on which a series of electrodes are mounted;
Figure 4 is a photograph showing an electrode of the illustrative
embodiment of the electrode array according to the present invention,
embedded within an Inter-electrode conductive medium; and
Figure 5 is a graph depicting signals obtained from an electrode an'ay
using a reference amplifier and digital differentiation for, on the left side, the
previous technology and, on the right side, the technology according to the
present invention.
DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT
The non-restrictive Illustrative embodiment of the electrode array
according to the present invention will now be described with reference to the
accompanying drawings.
The non-restrictive illustrative embodiment of the present invention will be
described in relation to an application of the electrode array to the detection of
electromyographic (EMG) activity of a subject's diaphragm. Therefore, in this
illustrative embodiment, the biological tissue is the subject's tissue nearby the.
diaphragm. However, it should be kept in mind that the present invention is not
limited to this particular application and can be used as well for detecting other
types of electrical activity, electromyographic or not, of a subject's body.
Structure of the illustrative embodiment oftfie electrode array
The illustrative embodiment of the electrode array comprises, as
electrode support, an esophageal catheter 10 (Figures 1-3). The esophageal
catheter 10 will enable insertion of the electrode an'ay through the subject's
esophagus and positioning of the electrodes in the vicinity of the subject's
diaphragm.
As illustrated in the cross sectional view of Figure 1, the esophageal
catheter 10 comprises a tube 11 made of polyurethane (Tecoflex™) including
four (4) longitudinal lumens 12-15. The lumens of the polyurethane tube 11
comprises:
- a larger-diameter lumen 12 used for feeding the subject (eventually an
extra lumen can be added for venting gas);
- a smaller-diameter lumen 13 through which electrical wires run; and
- two (2) smaller-diameter pressure lumens 14 and 15 used for supplying
or venting gas under pressure.
. Figure 2 Illustrates a proximal end section 16 of the esophageal catheter
10. As illustrated in Figure 2, the pressure lumen 15 is teed off to a gastric
pressure connector 17 while the pressure lumen 14 is teed off to an esophageal
pressure connector 18. The electrical wires 19 running through the lumen 13 are
teed off (electrically connected) to an electrical connector 20 for connection to
signal-processing equipments. Finally, a feeding connector 21 is connected to
the larger-diameter lumen 12.
Figure 3 illustrates the distal, free end section 22 of the catheter 10.
Isolation of a free end section of the wires 19 running through the lumen
13 is removed. The non-isolated free end section of each wire 19 is passed
through a small hole extending from the inner face of the lumen 13 to the outer
face of the polyurethane tube 11 (outer face of the catheter 10) to expose this
non-isolated free end section of the wire 19 outside the catheter 10. The
exposed non-isolated free end section of each wire 19 is then turned around the
outer face of the polyurethane tube 11 for at least one turn to thereby fomn one
electrode of a series of electrodes 23.
The catheter 10 comprises a series of longitudinally spaced apart small
holes each extending from the inner face of the lumen 13 to the outer face of the
polyurethane tube 11. The non-isolated free end sections of the wires 19 are
passed through the respective, longitudinally spaced apart holes extending from
the inner face of the lumen 13 to the outer face of the polyurethane tube 11, and
the exposed non-isolated free end sections of the wires 19 are turned around
the outer face of the tube 11 for at least one turn to fomn the series of
longitudinally spaced apart electrodes 23. As illustrated in Figure 3, the
longitudinal spacing between every pair of mutually adjacent electrodes 23 may
be constant (constant inter-electrode distance).
The series of electrodes 23 may comprise a ground/reference electrode.
The electrical wires 19 can be made of stainless steel coated with Teflon;
however, other wire materials such as silver, gold, copper, etc. can be used. As
well, wire isolation can be made of any other suitable electrically isolating
material.
In an alternative electrode design, a plurality of wires (isolated or non
isolated) 19 can mn through separate lumens of the catheter 10. Again, the
electrodes 23 would be obtained by exposing each bared end section of the
electrical wires through a hole in the wall of the polyurethane tube 11. The wires
19 will still be electrically and individually isolated between the electrodes 23 and
the first amplifier stage (not shown).
Gastric 24 and esophageal 25 Inflatable balloons are longitudinally
spaced apart on the catheter 10 and positioned on respective opposite sides of
the series of electrodes 23. The balloons 24 and 25 are made of medical grade
polyurethane and are mounted and fixed to the catheter 10 through hydrophilic
medical grade polyurethane commercialized under the trademari Holes such as 26 extend from the inside of the pressure lumen 15 to the
inside of the gastric balloon 24 to enable inflation and deflation of this gastric
balloon 24 through the pressure lumen 15 and the pressure connector 17. In the
same manner, holes such as 27 extend from the inside of the pressure lumen 14
to the inside of the esophageal balloon 25 to enable inflation and deflation of this
esophageal balloon 25 through the pressure lumen 14 and the pressure
connector 18. In operation, the gastric 24 and esophageal 25 balloons are
deflated to insert and remove the esophageal catheter 10. After insertion of the
catheter, the gastric 24 and esophageal 25 balloons are inflated to fixedly
position the series of electrodes 23 with respect, for example, the subject's
diaphragm in order to take measurements of tlie EIVIG activity of the subject's
diaphragm.
Finally, a series of longitudinally spaced apart holes such as 28 extend
from the inner face of the larger-diameter lumen 12 to the outer face of the
polyurethane tube 11 between the gastric balloon 24 and the free end 29 of the
catheter 10. Holes 28 will enable feeding of the subject through the connector 21
(Figure 2), the larger-diameter lumen 12 (Figure 1) and the series of
longitudinally spaced apart holes 28 (Figure 3).
Coating
The inter-electrode conductive medium can be formed of a conductive
material such as a semi-conductor, an absorbent material, a carbonized
material, a liquid-containing material, an electrolyte, etc. The choice of the
conductive material depends in part on whether the electrodes 23 will be
subjected to a wet or dry environment. For example, whereas hydrophilic and
absorbent materials are suitable for wet environments, hydrogels are more
suitable for dry environment. Semi-conductor polymers and carbonized, or in
other way made conductive materials can be used in both environments.
In the present illustrative embodiment, the outer face of the polyurethane
tube 11 of the catheter 10 as well as the electrodes 23 are first coated with a first
layer of hydrophilic medical grade polyurethane (HydroMed™ D3, 50% water
content) to fix the electrodes 23 on the outer face of the polyurethane tube 11. A
second layer of hydrophilic medical grade polyurethane (HydroMed™ 640, 90%
water content) is applied to the first layer of HydroMed™ D3 to provide a slippery
lubricious interface to sun-ounding tissue. The photograph of Figure 4 illustrates
an electrode 23 embedded in this double coating, fonning the above mentioned
inter-electrode conductive medium having a given resistivity for controlling
resistivity between the electrodes 23 of the series.
Those of ordinary skill in the art will understand that the coating of the
outpr face of the polyurethane tube 11 and the electrodes 23 can be a single-
layer coating or a multi-layer coating made of any suitable medical grade
material other than HydroMed™ D3 (50% water content) and" HydroIVIed™ 640
(90% water content).
Moreover, the above-mentioned ground/reference electrode can be one
of the electrodes 23, it can be integrated into the inter-electrode conductive
medium or, more simply, even be formed by this inter-electrode conductive
medium.
Figure 5 depicts signals obtained from an electrode array using a
reference amplifier and digital differentiation for, on the left side, the previous
technology (old technology) and for, on the right side, the technology according
to the present invention (new technology).
In Figure 5, the series of electrodes 23 is surrounded by tissue nearby the
subject's diaphragm. According to the previous technology (old technology),
when the electrodes 2-8 (fomning part of the series of electrodes 23) are covered
with no inter-electrode conductive medium, both channel Ch4 (electrodes 4 and
5) and channel Ch5 (electrodes 5 and 6) must be turned off when subjected to
. unmanageable DC offset. With the technology of the present invention (new
technology), the electrodes 4, 5 and 6 are covered by the inter-electrode
conductive medium (indicated by the gray area); in this manner DC offsets are
avoided and signals are maintained along all channels of the electrode array.
Operation of the illustrative embodiment of the electrode array
In the illustrative embodiment of the electrode array:
the electrodes of the series are made of a material having a first resistivity;
the biological tissue has a second resistivity;
the inter-electrode conductive mediunn Is made of a material having a
third resistivity considerably higher than the first resistivity, this third
resistivity is located within a range near the second resistivity of the
subject's biological tissue. Since the inter-electrode conductive medium
should not act as a short-circuit, the third resistivity will not be too low
compared with the second resistivity of the subject's biological tissue; the
third resistivity can even be slightly higher than the second resistivity.
When an electrode loses contact with the patient's tissue, the transmitted
disturbance comes from a high-impedance source. A reasonable conductance
between the electrodes 23 can neutralize this disturbance. When the contact
between one or more electrode(s) 23 and the subject's tissue is poor, but at
least one electrode 23 (and the reference/ground electrode, if it is not coated
with the Inter-electrode conductive medium) presents a good contact with
subject's tissue, the inter-electrode conductive medium still provides, by
controlling the resistivity between the electrodes 23, a defined signal potential on
the electrode(s) having lost contact, which represents a mean value of signal
potentials on the neighbouring electrodes, whereas capacitlve and/or inductive
disturbances are controlled.
In other words, in operation, when contact between at least one of the
electrodes 23 of the series and a subject's biological tissue is poor, the inter-
electrode conductive medium fornis a means for producing on this at least one
electrode an estimate of the electrical activity in the biological tissue, this
estimate being constituted by a mean value of electrical potentials produced on
neighbouring electrodes 23 of the series by the electrical activity in the subject's
biological tissue.
In this manner, voltage between electrodes that have maintained contact
with the subject's biological tissue and those that have lost connection with this
biological tissue is minimally altered.
Advantages
The illustrative embodiment of the electrode an-ay according to the
present invention presents, amongst others, the following advantages:
- the electrode array limits disturbances when contact is lost between one or
more electrodes and the subject's tissue;
- it prevents electrodes having no or poor contact with the patient's tissue from
inducing signal disturbances and instead replaces the disturbance with an
estimate of the signal activity in the region/area of concern;
- it makes it possible to measure down to very low signal frequencies;
- it prevents loss of reference/ground since the inter-electrode conductive
medium extends over the entire series of electrodes including the
reference/ground electrode;
- it minimizes disturbances of inductive or other nature by creating a stabilizing
interface environment;
- the coating (inter-electrode conductive medium) encapsulates edges and
protruding parts to reduce risl coating materials such as hydrophilic polymers and hydrogels reduces
friction with tissue, and facilitates placement of the electrode array through,
for example, the esophagus; and
- it makes it possible to Increase the gain in a first differential amplifier.stage.
Although the present invention has been described in the foregoing
specification by means of a non-restrictive illustrative embodiment, this
illustrative embodiment can be modified as wiN, within the scope of the
appended claims wrthout departing from the nature and spirit of the subject
invention.
WE CLAIM:
1. An electrode array assembly (Figure 3) comprising:
an electrode support (10);
a group of electrodes (23) mounted on the electrode support (10) for
measuring electrical activity in a subject's biological tissue; and
an inter-electrode conductive medium;
wherein the inter-electrode conductive medium has a given resistivity and is
applied to the electrodes (23) of the group and the electrode support (10) between
the electrodes for controlling, during electrical activity measurement, resistivity
between the electrodes (23) of the group to improve said electrical activity
measurement and wherein, when electrical contact between at least one electrode
(23) of the group and the subject's biological tissue is poor, the inter-electrode
conductive medium forms a means for producing on said at least one electrode an
estimate of the electrical activity in the subject's biological tissue, said estimate being
a mean value of electrical potentials produced on neighbouring electrodes of the
group by the electrical activity in the subject's biological tissue.
2. An electrode array assembly as claimed in claim 1, wherein the inter-
electrode conductive medium includes a reference electrode.
3. An electrode array assembly as claimed in claim 1, wherein:
the electrodes of the group are made of a material having a first resistivity;
and
the inter-electrode conductive medium has a second resistivity considerably
higher than the first resistivity.
4. An electrode array assembly as claimed in claim 1, wherein:
the subject's biological tissue has a first resistivity; and
the inter-electrode conductive medium has a second resistivity situated vi/ithin
a range near the first resistivity.
5. An electrode array assembly as claimed in claim 20, wherein the
conductive material of at least one of the first and second layers of the coating is
selected from the group consisting of: a semi-conductor, a semi-conductor polymer,
an absorbent material, a hydrophilic material, a carbonized material, a liquid
containing material, an electrolyte, and a hydrogel.
6. An electrode array assembly as claimed in claim 1, wherein the group of
electrodes is a linear array of electrodes.
7. An electrode array assembly as claimed in claim 1, wherein:
the electrode support comprises a catheter with a distal end section; and
the group of electrodes comprises a series of electrodes mounted on the
distal end section of the catheter for measuring electrical activity in a subject's
biological tissue.
8. An electrode array assembly as claimed in claim 7, wherein the series of
electrodes have a constant inter-electrode distance.
9. An electrode array as claimed in claim 7, wherein:
the catheter comprises an outer face and a lumen through which isolated
electrical wires run;
the electrical wires comprise respective non isolated distal end sections;
the distal end section of the catheter comprise a series of holes extending
from the lumen to the outer face of the catheter; and
the non isolated distal end section of each electrical wire extends through a
corresponding one of said holes and is turned around the outer face of the catheter
for at least one turn to form one of the electrodes of the series.
10. An electrode array assembly as claimed in claim 7, further comprising two
pressure balloons mounted on the catheter on respective opposite sides of the
series of electrodes, wherein the catheter comprises pressure lumens through which
the pressure balloons are inflated to fixedly position the series of electrodes about
the subject's biological tissue.
11. An electrode array assembly as claimed in claim 7, wherein:
the catheter comprises an outer face and a plurality of lumens;
the electrode array assembly comprises a plurality of electrical wires running
through the lumens of the catheter, respectively; and
each electrical wire comprises a non insulated distal end section exposed on
the outer face of the catheter to form one of the electrodes of the series, the non
insulated distal end section of said electrical wire being exposed through a hole
extending from the corresponding lumen to the outer face of the catheter.
12. An electrode array assembly as claimed in claim 1, wherein the inter-
electrode conductive medium comprises a coating formed of:
a first layer of hydrophilic medical grade polyurethane applied to both the
electrodes of the series and an outer face of the electrode support between the
electrodes; and
a second layer made of a slippery material and applied to the first layer to
form a lubricious interface to the subject's biological tissue.
13. A method of controlling an inter-electrode resistivity in an electrode array
including a group of electrodes for measuring electrical activity in a subject's
biological tissue, comprising:
applying an inter-electrode conductive medium;
wherein the inter-electrode conductive medium has a given resistivity between
the electrodes of the group, and the method comprises interconnecting the
electrodes of the group through said inter-electrode conductive medium to thereby
control, during electrical activity measurement, resistivity between said electrodes to
improve said electrical activity measurement; and
wherein, when contact between at least one electrode of the group and the
subject's biological tissue is poor, said method comprises producing on said at least
one electrode an estimate of the electrical activity in the subject's biological tissue
through the inter-electrode conductive medium, said estimate being a mean value of
electrical potentials produced on neighbouring electrodes of the group by the
electrical activity in the subject's biological tissue.
14. A method as claimed in claim 13, further comprising including a reference
electrode to the inter-electrode conductive medium.
15. A method as claimed in claim 13, wherein:
the electrodes of the group are made of a material having a first resistivity;
and said method comprises providing an inter-electrode conductive medium having a
second resistivity considerably higher than the first resistivity.
16. A method as claimed in claim 13, wherein:
the subject's biological tissue has a first resistivity; and
said method comprises providing an inter-electrode conductive medium
having a second resistivity situated with a range near the first resistivity.
17. A method as claimed in claim 19, wherein:
the electrode array comprises a support for the electrodes; and
interconnecting the electrodes of the group through the inter-electrode
conductive medium comprises applying the first layer of the coating of said
electrically conductive medium on the electrodes of the group and the electrode
support between the electrodes.
18. A method as claimed in claim 17, wherein applying the first layer of the
coating comprises applying a material selected from the group consisting of: a semi-
conductor, a semi-conductor polymer, an absorbent material, a hydrophilic matehal,
a carbonized material, a liquid containing material, an electrolyte, and a hydrogel.
19. A method as claimed in claim 13, wherein applying the inter-electrode
conductive medium comprises applying an inter-electrode conductive medium which
includes a coating formed of a first layer of conductive material applied to the
electrodes of the group and a second layer of slippery conductive material applied to
the first layer of conductive matehal to provide a lubricious interface to the subject's
biological tissue.
20. An electrode array assembly as claimed in claim 1, wherein the inter-
electrode conductive medium includes a coating formed of a first layer of conductive
material applied to the electrodes of the group and to the electrode support between
the electrodes and a second layer of slippery conductive material applied to the first
layer of conductive material to provide a lubricious interface to the subject's
biological tissue.
21. An electrode array assembly as claimed in claim 20, wherein the
electrically conductive material of the first layer of the coating includes hydrophilic
medical grade polyurethane.
22. An electrode array assembly as claimed in claim 21, wherein the
hydrophilic medical grade polyurethane has a water content of about 50%.
23. An electrode array assembly as claimed in claim 20, wherein the
electrically conductive material of the second layer of the coating includes hydrophilic
medical grade polyurethane.
24. An electrode array assembly as claimed in claim 23, wherein the
hydrophilic medical grade polyurethane has a water content of about 90%.

There is disclosed an electrode array assembly comprising an electrode support (10); a group of electrodes (23) mounted on the electrode support (10) for measuring electrical activity in a subject's biological tissue; and an inter-electrode conductive medium; wherein the inter-electrode conductive medium has a given resistivity and is applied to the electrodes (23) of the group and the electrode support
(10) between the electrodes for controlling, during electrical activity measurement, resistivity between the electrodes (23) of the group to improve said electrical activity
measurement and wherein, when electrical contact between at least one electrode (23) of the group and the subject's biological tissue is poor, the inter-electrode conductive medium forms a means for producing on said at least one electrode an
estimate of the electrical activity in the subject's biological tissue, said estimate being
a mean value of electrical potentials produced on neighbouring electrodes of the group by the electrical activity in the subject's biological tissue

Documents:

02327-kolnp-2005-abstract.pdf

02327-kolnp-2005-claims.pdf

02327-kolnp-2005-description complete.pdf

02327-kolnp-2005-drawings.pdf

02327-kolnp-2005-form 1.pdf

02327-kolnp-2005-form 3.pdf

02327-kolnp-2005-form 5.pdf

02327-kolnp-2005-international publication.pdf

2327-KOLNP-2005-FORM-27.pdf

2327-kolnp-2005-granted-abstract.pdf

2327-kolnp-2005-granted-assignment.pdf

2327-kolnp-2005-granted-claims.pdf

2327-kolnp-2005-granted-correspondence.pdf

2327-kolnp-2005-granted-description (complete).pdf

2327-kolnp-2005-granted-drawings.pdf

2327-kolnp-2005-granted-examination report.pdf

2327-kolnp-2005-granted-form 1.pdf

2327-kolnp-2005-granted-form 18.pdf

2327-kolnp-2005-granted-form 3.pdf

2327-kolnp-2005-granted-form 5.pdf

2327-kolnp-2005-granted-gpa.pdf

2327-kolnp-2005-granted-reply to examination report.pdf

2327-kolnp-2005-granted-specification.pdf

abstract-02327-kolnp-2005.jpg


Patent Number 238086
Indian Patent Application Number 2327/KOLNP/2005
PG Journal Number 04/2010
Publication Date 22-Jan-2010
Grant Date 21-Jan-2010
Date of Filing 22-Nov-2005
Name of Patentee MAQUET CRITICAL CARE AB
Applicant Address RONTGENVAGEN 2, SE-171 95 SOLNA
Inventors:
# Inventor's Name Inventor's Address
1 LINDSTROM, LARS LAKEVALLSGATAN 46, S-431 69 MOLNDAL
2 SINDERBY, CHRISTER 40 HUMBERVIEW ROAD, TORONTO, ONTARIO M6S, 1W6
PCT International Classification Number A61B 5/42
PCT International Application Number PCT/CA2004/000550
PCT International Filing date 2004-04-08
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/470,339 2003-05-13 U.S.A.
2 10/726,750 2003-12-02 U.S.A.