Commissioner's Decision
Subject Matter, Sec. 2: Detection of Pathogens
A continous small amount of blood from an individual flows through
an exterior absorbent device and returned to the individual.
Biocompatible material in the device attract the pathogens after
removal of the device its contents are tested in vitro. Method
claims are acceptable.
Rejection: Withdrawn
This decision deals with Applicant's request for review by the Commissioner
of Patents of the Final Action on application 319,105 (Class 150-11) filed
January 4, 1979. It is assigned to Boehringer Mannheim G.m.b.H., and is
entitled PROCESS AND DEVICE FOR THE DETECTION OF PATHOGENS. The inventors
are F. Keller and H. Henneman. The Examiner in charge issued a Final
Action on November 26, 1982 refusing to allow the application. During a
telephone conversation on December 31, 1986 with Applicant's Patent Agent,
Mr. Kevin Murphy, agreement to a review of the subject matter under
rejection was reached, and the request for an oral hearing withdrawn.
The application describes a method and apparatus for the detection of
pathogens in blood. A continuous small amount of blood from a person is
caused to flow in the presence of an anticoagulant agent through an
exterior adsorbent device, and to return to the person. The device
contains a biocompatible material to permit binding thereto of any
pathogens in the blood. The device is removed and its contents tested in
vitro. The sole drawing, reproduced below, depicts the system. The blood
flows exteriorly via tube 14 through adsorbent material 5 in device 2 to
tube 15. End caps 8 and 9 permit easy removable of the device.
(See formula 1)
The Examiner rejected the claims directed to the method. He reasoned that
by incorporating the extracorporeal circulation of the blood flow from the
human body into a diagnostic procedure, the human body plays an integral
part in the process. He indicated the claims to the device are allowable.
In his response to the Final Action, the Applicant points out that the
essential steps of the invention occur externally of the body, and that
there is no recitation of a human body in the method claims. He argues, in
part, as follows:
It is not seen why the claimed method should be considered any
different from other diagnostic methods carried out in vitro.
In other diagnostic methods a sample of body fluids such as
blood or urine is taken from the body, by, for example, a blood
lancet, and the test is conducted on the fluid and the fluid is
then disposed of. In the present case the fluid, i.e., blood,
is taken from the body, but instead of "disposing" of the fluid
after the testing, it is returned to the body, however, this is
not at all essential to the character of the diagnostic process
which is essentially an in vitro process and certainly the
selective binding of the pathogen to separate it from the
blood, and the detection step itself are conducted in vitro
outside the body.
....
It is immaterial whether the activity or process carried out on the
fluid is carried out discontinuously or continuously, and it is
immaterial whether the fluid is subsequently returned to the body.
What is notable in the claimed process is that the essential steps of
the invention, namely the removal of the pathogen from the blood and
the detection step, take place neither within the body nor on the
surface of the body, but completely externally and remote from the
body.
The issue before the Board is whether or not the process claims 1 to 32,
and 54 to 62, are patentable within the definition of Section 2 of the
Patent Act. Claim 1 reads:
A process for the detection of pathogens in blood in the presence of
an anticoagulant agent, Wherein the pathogen is separated from the
blood in an extracorporeal circulation of the blood with a
biocompatible material effective to selectively bind the pathogen,
Whereafter the pathogen is detected in vitro.
In the application we note a feature of the Applicant's method is that a
small amount from the person's total blood volume is circulated externally
of the body, and that the amount is continuously withdrawn and returned.
The Applicant identifies deficiencies in previous systems for diagnostic
detection of pathogens, the main ones being an intermittent flow of fluid,
and the inclusion of antibiotics in the blood of people being tested for
pathogens. In Applicant's response of September 30, 1981, he discusses the
importance of the small volume, as follows:
... the small volume of the column is a not insignificant feature of
the device of the present invention since the small volume prevents a
drop in blood pressure, thrombocytopaenia, loss of immune globulins,
adsorption of administered medicaments and at the same time haemolysis
is substantially minimized.
Applicant stresses that his method of using continual flow of blood
provides an opportunity to obtain samples of pathogens that are randomly
distributed throughout a person's body, whereas in intermittent samples
pathogens may not be present, or may be obscured due to the presence of
antibiotics. He points out that his method returns the blood to the body
after it passes through his sampling device, whereas intermittent samples
are not. Applicant notes his process of extended continual sampling
enables a large part of the total volume to be sampled. He relates that
his sampling device is taken out of the line of continual flow and tested
elsewhere in vitro.
We are persuaded that in the present arrangement the step of externally
adsorbing certain elements does not amount to a treatment of a person's
blood, nor to a treatment of a human body, since no steps of treating the
blood are introduced, and the blood is merely returned to the body. We
note for example, that when a patient, because of renal failure, is treated
by haemodialysis, Applicant's arrangement is designed to be connected into
the arterial link of the tube system of the dialysis machine after the
blood pump.
No substance is added by Applicant's method to the blood returning to the
body. That blood is recirculated along with the blood present in the body,
and any pathogens present in the body are caught up in the flow.
Continuous withdrawal of blood thus provides an extended sampling for
pathogens by the adsorbent device Which is designed to remove them.
In the Swift & Co.'s Application (New Zealand) (1961) R.P.C. 147, there was
considerable discussion concerning whether or not a method of injecting an
enzyme into an animal's body prior to slaughtering the animal, to enable
circulation of the enzyme through the animal's circulatory system for
purposes of tenderizing the meat by the action of the enzyme, was a manner
of manufacture. The Court looked to the ultimate end result of the
process, namely the production for commercial purposes of a carcass having
tenderized meat. The Court noted there might have been an affect on the
animal's metabolism, but did not consider the process to be equivalent to a
medical process.
Here, Applicant is using a person's circulatory system to emit a continual
small flow of blood and to take back substantially that same quantity of
flow. Nothing is added to the blood, although certain elements therein may
be removed. If we look to the end use of Applicant's process for the
detection of pathogens in blood, we see no treatment of the blood is
contemplated nor effected. Moreover, no curing or alteration of the
metabolism of the body is obtained.
In our view, the arrangement described by Applicant pertains to a
diagnostic method and not to a method of medical treatment. We are
satisfied therefore, the method set forth in the application is directed to
patentable subject matter. Accordingly, we are unable to sustain the
rejection by the Examiner on the basis that the incorporation of the
function of the human body renders claims 1 to 32, and 54 to 62
unpatentable.
We are not so sure however, that the rejected method claims incorporate all
the steps that are described in the application, and that have been argued
by the Applicant in his responses, as forming the method of the invention.
For example, the claims do not describe that a limited quantity of blood
with respect to the total volume in the body is externally circulated in
the presence of an anticoagulant in an extracorporeal line and returned to
the body, nor that the extracorporeal line has removably connected therein
a device containing an adsorbent biocompatible material so that the device
may be removed for diagnostic detection in vitro for pathogens that may
have adhered to such material.
We recommend that the rejection of method claims 1 to 32, and 54 to 62 for
being directed to non patentable subject matter, be withdrawn, and that the
application be returned to the Examiner for normal further prosecution.
M.G. Brown S.D. Kot
Acting Chairman Member
Patent Appeal Board
I concur with the findings and the recommendation of the Patent Appeal
Board. Accordingly I withdraw the rejection of claims 1 to 32, and 54 to
62, and I remand the application to the Examiner for normal continued
prosecution.
J.H.A. Gari‚py
Commissioner of Patents
dated at Hull, Quebec
this 26th day of Avgust, 1987
Swabey, Mitchell, Houle, Marcoux & Sher
111 Richmond Street West
Suite 200
Toronto, Ontario
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