Ex Parte LI et al

Patent Trial and Appeal Board

Nov 27, 2012

11468481 (P.T.A.B. Nov. 27, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
__________

Ex parte DUN ALEX LI, JOSEPH CASEY CRAGER,
and DOUGLAS KARL JOHNSON
__________

Appeal 2011-006662
Application 11/468,481
Technology Center 3700
__________

Before MELANIE L. McCOLLUM, STEPHEN WALSH, and
ERICA A. FRANKLIN, Administrative Patent Judges.

FRANKLIN, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134(a) involving claims to
tracking systems and methods for instrument navigation. The Patent
Examiner rejected the claims as failing to comply with the written
description requirement, as being directed to non-statutory subject matter, as
anticipated, and as obvious. We have jurisdiction under 35 U.S.C. § 6(b).
We reverse.

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STATEMENT OF THE CASE
The invention concerns “an improved system and method for
detecting errors in [an] electromagnetic tracking system.” (Spec. [05].)
Claims 1-8 and 11-20 are on appeal. Claims 1, 4, 8, and 14 are
representative and read as follows:
1. A tracking system for instrument navigation, said system comprising:
a transmitter for transmitting a signal, said signal identifying
transmitter coordinates;
a field sensing unit for determining the location of the field sensing
unit within said transmitter coordinates, said field sensing unit having a
plurality of sensors, said plurality of sensors creating a plurality of virtual
points, at least one of said virtual points being a non-fixed virtual point; and
a processor for processing field integrity detection values for said
virtual points.

4. The system of claim 2, wherein said field sensing unit is attached to a
medical instrument, and wherein said at least one of said virtual points is
non-fixed with respect to said medical instrument.

8. A tracking system for medical instrument navigation, said system
comprising:
a transmitter for transmitting a signal, said signal identifying
transmitter coordinates;
a field sensing unit secured to the medical instrument for determining
the location of the field sensing unit within said transmitter coordinates, said
field sensing unit having more than two sensors that create a plurality of
virtual points, at least one of said virtual points being fixed with respect to
the medical instrument, and at least another of said virtual points being non-
fixed with respect to the medical instrument; and
a processor for processing field integrity detection values for said
virtual points.

14. A method for instrument navigation, said method comprising using at
least one processor to perform at least the following:
assigning a plurality of virtual points to a plurality of sensors, at least
one of the virtual points being a non-fixed virtual point;
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determining virtual point locations for said non-fixed virtual point;
adjusting vector values for vectors terminating at said non-fixed
virtual point;
computing field integrity values for said plurality of virtual points;
and,
communicating an error signal if a field integrity value is greater than
a threshold value.

(App. Br. 23-25, Claims App‟x.)(Emphasis added).

The Examiner rejected the claims as follows:
• claims 4, 8, 11, 12, and 13 under 35 U.S.C. § 112, first paragraph,
as failing to comply with the written description requirement;
• claims 14-20 under 35 U.S.C. § 101, as being directed to non-
statutory subject matter;
• claims 1-13 under 35 U.S.C. §102(b) as anticipated by Schwartz;
1

and
• claims 14-20 under 35 U.S.C. § 103(a) as unpatentable over
Schwartz and Sherman.
2

WRITTEN DESCRIPTION
The Examiner‟s position is that the Specification does not describe
that a virtual point is non-fixed with respect to a medical instrument, as
recited by claims 4 and 8, and is therefore new matter. (Ans. 4, 7.)
Specifically, the Examiner found that the Specification‟s “discussion of non-

1
Patent Application Publication No. US 2004/0220471 A1 by Yitzhack
Schwartz, published Nov. 4, 2004.
2
Patent Application Publication No. US 2007/0167741 A1 by Jason T.
Sherman et al., filed Dec. 30, 2005, published Jul. 19, 2007.
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fixed point(s) makes no mention of a reference with respect to the medical
instrument.” (Id.)
Appellants contend that the Specification fully supports the claim
limitation of virtual points that are non-fixed with respect to a medical
instrument by describing “„at least one of the virtual point[s] is a non-fixed
virtual point” and that it may be “located at the tip of a medical
instrument.‟” (App. Br. 6, 7.) Appellants also assert that the Specification
further describes “the location of a non-fixed virtual point may be
determined based on the medical instrument in use.” (Id. at 6.)
For the reasons discussed by Appellants, we agree that the
Specification supports the virtual points that are non-fixed with respect to a
medical instrument. (See App. Br. 6-7; Reply Br. 3-4.) Additionally, we
note that the Specification states, “[i]f during surgery, the surgeon alters the
location of the tip of the surgical instrument, by utilizing an attachment, the
virtual point may be adjusted to correspond with the location of the tip of the
attachment.” (Spec. [40].) The Specification explains how the virtual point
is non-fixed with respect to the instrument in this example by stating, “the
virtual point 370 may be adjusted according to the location of the tip of the
surgical instrument. The location of the virtual point 370 may be adjusted
for various instrument attachments that may alter the location of the
instrument.” (Id.)
Accordingly, we reverse the new matter rejection.

NON-STATUTORY SUBJECT MATTER
The Examiner‟s position is that claims 14-20 are directed to non-
statutory subject matter because “the steps of assigning virtual points and
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determining their corresponding locations, along with the recited
computations could be executed as a purely mental process and thus the
claims are broad enough to read on an abstract idea per se.” (Ans. 4.)
Appellants contend that “claims 14-20 are, indeed, tied to at least one
processor „that accomplishes the method steps‟” because independent claim
14 recites “said method comprising using at least one processor to
perform at least the following….” (App. Br. 6.) We agree.
Accordingly, we reverse the non-statutory subject matter rejection.

ANTICIPATION/OBVIOUSNESS
The Examiner‟s position is that Schwartz disclosed the claimed
invention, and specifically found that Schwartz disclosed a field sensing unit
for determining the location of the field sensing unit within a local
coordinate system as determined by the transmitter, wherein the field
sensing unit comprises a plurality of coil sensors. (Ans. 5.) According to
the Examiner, “[t]he sensor locations of Schwartz …correspond to a number
of virtual points and each is non-fixed in that the sensor-tipped instrument is
freely movable by the user within the local coordinate reference space….”
(Id.) The Examiner found that “[t]he location of the virtual point is based
upon the location of the sensor coils within the medical instrument in use.”
(Id.) Additionally, the Examiner found that the Schwartz method is specific
to assigning a plurality of virtual points to the number of sensor-coils and
that the calculation(s) of coordinate locations in space is understood to
necessarily include determining vector values that terminate at the virtual
points (or the sensor-coil positions in space). (Id.) The Examiner also found
that “[a] field value is used to determine the coordinate locations of the
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virtual points (or sensor-coil positions in space) as in [0043] in which the
magnetic field is sensed.” (Id. at 5-6.) In the Response to Argument, the
Examiner reasoned that the coordinate locations of the sensors are the virtual
points and that these virtual points are created by the sensors (coils). (Ans.
8.)
Appellants contend that while Schwartz disclosed a location sensor
that generates signals for determining the location coordinates of the distal
end of the sheath, “there is nothing in Schwartz that describes, teaches or
suggests that the location sensor 128 creates any virtual points, such as
set forth in the claims ….” (App. Br. 8.)
After considering all the evidence and arguments, we find that
Schwartz does not anticipate the claimed invention. Specifically, we do not
find that the evidence supports the Examiner‟s finding that Schwartz
disclosed sensors creating a plurality of virtual points. The Specification
explains “[t]he virtual vectors generally begin at a sensor and terminate at a
virtual point.” (Spec. [28].) The Specification contemplates that the sensors
may “project” the virtual points. (Spec. [35]; see also [27] and Fig 1.) Thus,
we disagree with the Examiner that the virtual points are merely coordinate
locations of the sensors. (See Ans. 8.) As the Appellants have asserted,
Schwartz does not teach that its sensor projects virtual vectors to terminate
at virtual point, as described in the instant Specification. Consequently, we
find that the Examiner has not shown that Schwartz disclosed every
limitation of the claimed invention.
Accordingly, we reverse the anticipation rejection.
Because the Examiner relies on the same reasoning as discussed with
respect to anticipation rejection to find that Schwartz disclosed the step of
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assigning a plurality of virtual points to a plurality of sensors (Ans. 6, 11),
we also conclude that the Examiner has not established a prima facie case of
obviousness for method of claim 14 and dependent claims 15-20.
Accordingly, we reverse the obviousness rejection.

SUMMARY
We reverse each of the Examiner‟s rejections.

REVERSED

cdc