Ex Parte Irion et al

Patent Trial and Appeal Board

Jul 31, 2013

11432014 (P.T.A.B. Jul. 31, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
__________

Ex parte KLAUS M. IRION, ANDRE EHRHARDT,
and ANDREAS SCHMAL
__________

Appeal 2011-012316
Application 11/432,014
Technology Center 3700
__________

Before TONI R. SCHEINER, FRANCISCO C. PRATS, and
ERICA A. FRANKLIN, Administrative Patent Judges.

SCHEINER, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal1 under 35 U.S.C. § 134 from the final rejection of
claims 1-14 and 18-34, directed to a light system for medical photodynamic
applications. The claims have been rejected as obvious. We have
jurisdiction under 35 U.S.C. § 6(b).
We reverse.

1 Appellants identify the Real Party-In-Interest as Karl Storz GmbH & Co.
(App. Br. 2.)

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STATEMENT OF THE CASE
The present invention is directed to a light system for medical
photodynamic applications, for example, photodynamic therapy.
Claims 1-14 and 18-34 are pending and on appeal. Claims 15-17 have
been canceled (App. Br. 2). Claim 1 (bracketed roman numerals added) is
representative of the subject matter on appeal:
1. A light system for medical photodynamic applications, comprising
[i.] an incoherent light source emitting light with a power,
[ii.] a light guide having a distal end and an entrance interface, said
entrance interface and said light source having a position relative to one
another and being able to be positioned relative to one another,
[iii.] a luminous power meter for measuring a luminous power
emitted at said distal end of said light guide,
[iv.] a motorized positioning unit for positioning said entrance
interface and said light source relative to one another,
[v.] a control unit controlling said positioning unit as a function of
said luminous power measured by said luminous power meter,
[vi.] an operating unit for receiving real-time input from a user
indicating the user's tolerance to the luminous power and for varying the
luminous power based on said real-time input from said user, and
[vii.] an input unit that receives an indication of a total radiation dose
that is to be emitted from said distal end of said light guide, said total
irradiation dose being a function of both irradiation time and luminous
power, said indication of a total irradiation dose being used to continuously
calculate and adjust the irradiation time as a function of the power of said
light source, and said position of said entrance interface of said light guide
and of said light source relative to one another.
The Examiner relies on the following evidence:
Hoerenz et al. US 4,657,013 Apr. 14, 1987
Schlager et al. US 4,860,172 Aug. 22, 1989
Fujii et al. US 5,335,309 Aug. 2, 1994
Fujishima et al. US 5,855,595 Jan. 5, 1999
Azar US 6,214,034 B1 Apr. 10, 2001
Groseth et al. US 2004/0260365 A1 Dec. 23, 2004
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The claims stand rejected as follows:
Claims 1-3, 7-12, 19-26, and 30-31 under 35 U.S.C. § 103(a) as
unpatentable over Fujii, Hoerenz, and Schlager (Ans. 4-7).
Claims 4-6 and 27-29 under 35 U.S.C. § 103(a) as unpatentable over
Fujii, Hoerenz, Schlager, and Fujishima (Ans. 7).
Claims 13, 14, 32, and 33 under 35 U.S.C. § 103(a) as unpatentable
over Fujii, Hoerenz, Schlager, and Azar (Ans. 8).
Claims 18 and 34 under 35 U.S.C. § 103(a) as unpatentable over Fujii,
Hoerenz, Schlager, and Groseth (Ans. 8-9).
FINDINGS OF FACT
The following findings of fact are supported by a preponderance of
the evidence of record.
1. Photodynamic therapy is a treatment method wherein
compounds called photosensitizers are “applied specifically to malignant
tissue or . . . collect in malignant tissue. When these photosensitizers are
irradiated with light of specific wavelengths, a phototoxic effect takes place
which can destroy the tissue in which the photosensitizers have collected”
(Spec. ¶ 4).
2. The Specification discloses an apparatus in which incoherent
light is condensed and focused at the entrance interface of a light guide (i.e.,
the proximal end of the light guide), and transmitted through the distal end
of light guide for application to a tissue treated with a photosensitizer (Spec.
¶¶ 10, 11).
3. “In order to achieve a maximum effect of the treatment, the
greatest possible amount of light has to be applied to the [photosensitizer-
treated] tissue” (Spec. ¶ 5). The luminous power at the distal end of the light
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guide is “maximized by a procedure in which [a] positioning unit moves . . .
the light source and the entrance interface of the light guide relative to one
another in three spatial directions . . . and in each case determines the
luminous power maximum in the spatial direction” (id. at ¶ 16).
4. The Specification further teaches that a “pain sensation . . . can
occur upon abrupt application of the maximum irradiation” (Spec. ¶ 30), but
“is greatly reduced if the power at the distal end of the light guide is
increased slowly to the maximum irradiation level” (id.).
3. According to the Specification, the claimed apparatus “allows
the luminous power at the distal end of the light guide to be directly
measured” and “transmitted, together with the position of the entrance
interface of the light guide and of the light source relative to one another, to
a control unit” (Spec. ¶ 11). The control unit “then changes the position of
the entrance interface of the light guide and of the light source relative to
one another such that a desired luminous power is obtained at the distal end
of the light guide” (id.).
At the same time, the claimed apparatus “provides remote control . . .
with which a patient can adjust the luminous power at the distal end of the
light guide in order to adapt it to his or her individual sensitivity to pain”
(Spec. ¶ 32). “If the luminous power is increased, the irradiation time
decreases” (id.), and vice versa.
4. Fujii discloses an industrial incoherent light-beam heating
apparatus. Figure 1 of Fujii is reproduced below:
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Figure 1 is a diagram showing the general structure of Fujii’s
incoherent light-beam heating apparatus. The apparatus comprises:
a radiating lamp 1;
a reflecting mirror having first and second focal points 4,6 for
condensing light from the radiating lamp;
an optical fiber 5 to which the condensed light is input;
a photodetector 8 which detects the light incident on the light
receiving end of the optical fiber, where the intensity of the incident light is
determined by the position of the emitting portion of the radiating lamp with
respect to the first focal point;
a radiating lamp fitting mechanism provided with a drive mechanism
capable of moving the light emitting portion of the radiating lamp to an
optional position in the vicinity of the first focal point of the ellipsoidal
reflecting mirror;
a photoelectric converter for photoelectrically converting an optical
output of the photodetector;
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and an arithmetic drive circuit for computing a moving direction and a
moving quantity of the radiating lamp from the output of the photoelectric
converter 9 and outputting a driving signal to the drive mechanism of the
radiating lamp fitting mechanism;
and an arithmetic circuit for computing the total quantity of light
energy incident to the light receiving end of the optical fiber.
(Fujii, col. 2, ll. 25-48.)
5. Hoerenz discloses an operating microscope which provides
field illumination during ophthalmic surgery, but does not provide
therapeutic light. Hoerenz explains:
In ophthalmic microsurgery, field illumination can
damage the retina even though the focus of surgery is in a plane
removed from the retina, for example an operation such as a
radial keratotomy upon the cornea. It is . . . the surgeon's
responsibility to make sure that, even when performing a
particular operation which does not involve the retina, he
nevertheless avoids damaging exposure of the retina to his
illumination. The problem is aggravated by the fact that
illumination brightness will vary in the course of a particular
procedure, in that bright illumination is only needed for short
intervals, and there can be intervals of no illumination and/or of
reduced illumination. Retinal damage is a function of time
integration of the different levels of illumination, over the full
course of a given procedure; the damage becomes irreparable
once a tolerance level of the integrated value has been
exceeded.
(Hoerenz, col. 1, ll. 9-25.)
6. Hoerenz discloses “instrumentation with means for preselecting
a professionally determined conservative limit of illumination dosage for a
given operative procedure on the eye,” and “means whereby remaining
exposure time at a given illumination level may be instantly available at all
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times throughout the operative procedure” (Hoerenz, col. 1, ll. 41-47).
Specifically,
[Hoerenz] relies upon continuously monitoring the illuminance
level of a small sampling fraction of the total projected-light
flux of the field-illuminating system of an operating
microscope, the sampling being optionally within the projection
system, or taken elsewhere. The sampled illuminance is in the
form of an electrical signal which is continuously time-
integrated to provide a continuous display of the dosage as it
builds in the course of an operative procedure. Provision is
made for the surgeon to preset what he chooses to be the safe
upper limit of integrated exposure . . . and the instrument
continuously indicates the remaining time for him to complete
his operation, should he continue at the current level of
illumination.
(Id. at col. 1, ll. 53-68.)
Thus, the illumination referred to in Hoerenz is largely due to the field
illumination system of the microscope, rather than the therapeutic light used
to perform the operative procedure.
7. Schlager teaches that “[l]asers are broadly applied in a wide
range of scientific, industrial, military and medical applications” (Schlager,
col. 1, ll. 12-13), but are “expensive to manufacture and use, and certain
types of lasers useful in medical applications cannot be used in fiber optic
systems” (id. at col. 1, ll. 25-27). As an alternative, Schlager discloses “an
apparatus for producing an intensely bright, highly focused beam of light
from a conventional incoherent lamp source . . . [which] is particularly
suited for certain medical applications as a substitute for a laser” (id. at col.
1, ll. 5-11).

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DISCUSSION
There are four rejections based, in whole or in part, on the combined
teachings of Fujii, Hoerenz, and Schlager, so we will discuss the rejections
together.
The Examiner’s findings with respect to Fujii are set forth on pages 5
and 6 of the Answer, and we agree that they are supported by the record. In
a nutshell, Fujii discloses an apparatus that incorporates all of the elements
and limitations recited in clauses i-v of claim 1 (FF4), except that Fujii’s
luminous power meter (i.e., Fujii’s photodetector 8) is positioned to measure
the luminous power at the proximal end of the light guide (focal point 6 of
Fujii’s optical fiber 5), rather than the distal end of the light guide.
The Examiner acknowledges that Fujii lacks the operating unit and
input unit recited in clauses vi and vii of claim 1, and relies on Hoerenz to
supply these last two elements. Specifically, the Examiner finds that
Hoerenz “teaches an operating unit (control 30, Fig. 1) for varying
the power/level of light . . . [which] is considered real-time input from the
user as the user decides the proper power/level of irradiance delivered”
(Ans. 5), and “an input unit with which the total irradiation time is
continuously calculated” (id. at 6).
The Examiner cites Schlager as evidence that highly focused
incoherent light devices like Fujii’s “can be used in both industrial and
medical applications” (id.) as alternatives to lasers, and concludes that it
would have been obvious for one of ordinary skill in the art “to include the
medical input and operating unit taught by Hoerenz in the industrial light
device taught by Fujii in order to control the specific dosage applied to the
patient” (id.).
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Appellants contend that Hoerenz “does not disclose an operating unit
for receiving real-time input from a user, which varies the luminous power
of the light source power” (App. Br. 8). Rather, Hoerenz “uses a separate
detecting unit . . . which detects light emanating from the illuminated area”
(id.), and therefore does not disclose “any connection between a power level
control and the light source dosimeter” (id.). Appellants contend:
Since, Hoerenz does not disclose a connection between a
[therapeutic] light source and the controls of the power levels of
the [illumination] light source with the dosimeter, . . . Hoerenz
does not teach an input unit that continuously calculates and
adjusts the irradiation time as a function of the power of said
[therapeutic] light source
(id. at 8-9).
Stated another way, Appellants contend:
[T]he irradiation time according to Hoerenz is calculated based
on an independent measurement of the light levels in the target
area and since the irradiation time is not calculated based on the
power level of the light source, the calculation obviously does
not involve the position of the entrance interface of the light
guide and the light source relative to one another.
(Id. at 12-13.)
Having considered the respective positions of Appellants and the
Examiner, we agree with the Examiner that Schlager provides evidence that
one of ordinary skill in the art would have recognized that certain principles
of industrial devices that use focused incoherent light as a tool would apply
equally well to medical devices. We further recognize that elements need
not be physically combinable to render an invention obvious. Orthopedic
Equip. Co. v. United States, 702 F.2d 1005, 1013 (Fed. Cir. 1983) (“Claims
may be obvious in view of a combination of references, even if the features
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of one reference cannot be substituted physically into the structure of the
other reference.”).
However, even if one were to combine the various features of the
references, we agree with Appellants that “not all the features of the pending
independent claims are shown [or suggested] in the prior art” (App. Br. 13).
As discussed above, Hoerenz calculates irradiation time based on an
independent measurement of the light level in the target area which is
largely due to the field illumination system of the microscope that is used to
illuminate the surgical site, and which incidentally illuminates the retina as
well (FFs 5, 6). Therefore, we agree with Appellants that Hoerenz does not
teach or suggest continuously calculating or adjusting irradiation time based
on the power of the therapeutic light source, and the position of the entrance
interface of the light guide and the light source relative to one another, as
required by the claims.
SUMMARY
The rejection of claims 1-3, 7-12, 19-26, and 30-31 as unpatentable
over Fujii, Hoerenz, and Schlager is reversed.
The rejection of claims 4-6 and 27-29 as unpatentable over Fujii,
Hoerenz, Schlager, and Fujishima is reversed.
The rejection of claims 13, 14, 32, and 33 as unpatentable over Fujii,
Hoerenz, Schlager, and Azar is reversed.
The rejection of claims 18 and 34 as unpatentable over Fujii, Hoerenz,
Schlager, and Groseth is reversed.

REVERSED
cdc