Alcohol Monitoring Systems, Inc. (AMS) appeals the
district court’s grant of summary judgment that defen-
dants Actsoft, Inc. (Actsoft), Ohio House Monitoring
Systems Inc. (Ohio House), and U.S. Home Detention
Systems and Equipment, Inc. (U.S. Home) (collectively,
Defendants) do not infringe the asserted claims of U.S.
Patent No. 5,220,919 (’919 patent).
From "Alcohol Monitoring" as to text from a preamble:
AMS argues that step (c) does not require the “calcu-
lation of a percentage of blood alcohol content.” We agree.
AMS asserts that the district court improperly treated the
preamble language “monitoring the percentage of blood
alcohol content” as a limitation by requiring a calculation
of BAC in step (c). Generally, a preamble does not limit
the scope of claims unless “it recites essential structure or
steps, or if it is necessary to give life, meaning, and vital-
ity to the claim.” See, e.g., Am. Med. Sys., Inc. v. Biolitec,
Inc., 618 F.3d 1354, 1358 (Fed. Cir. 2010) (internal cita-
tions omitted). We previously held that a preamble is not
limiting where it “merely gives a descriptive name to the
set of limitations in the body of the claim that completely
set forth the invention.” IMS Tech., Inc., 206 F.3d at
1434-35 (Fed. Cir. 2000). Here, “monitoring the percent-
age of blood alcohol” is such a descriptive namnot additionally
limit the scope of the claims.
But, as to calculations:
Under AMS’s proposed construction, the “percentage”
is not a quantifiable measurement. A person of skill in
the art would be unable to calculate what “percentage” of
alcohol went into the measurement device, compared to
the total alcohol expelled through the body in its entirety.
Even if the device could conceivably quantify the amount
of alcohol entering into the device, the device could not
determine the total quantity of alcohol expelled through
Because AMS’s proposed construction is not quantifi-
able, it conflicts with claims 19 and 21, which depend
from claim 14. Claims 19 and 21 require storing an
interferant indication “if a change in said percentage of
alcohol exceeds a predetermined . . . rate.” It logically
follows that the claimed percentage must itself be a
numerical value or one could not compare “a change in
said percentage” to “a predetermined rate” as required by
the dependent claims. Therefore, claim 14 requires the
actual calculation of a percentage and AMS’s proposed
construction cannot be correct.
Thus, properly construed, step (c) requires the meas-
urement of an amount of alcohol being emitted from an
individual’s skin and the calculation of a percentage that
approximates blood alcohol content (e.g., transdermal
alcohol content). This construction is consistent with both
the intrinsic record and the extrinsic testimony from
AMS’s inventor and expert witness.
As to the doctrine of equivalents:
Under the facts before us, a reasonable jury could
conclude that the HAS device’s voltage measurements
perform substantially the same function, in substantially
the same way, to achieve substantially the same result as
the calculation of a percentage TAC. Therefore, the
district court erred in granting summary judgment of
noninfringement under the doctrine of equivalents.
For the reasons discussed above, we affirm the dis-
trict court’s grant of summary judgment of no literal
infringement, reverse the district court’s grant of sum-
mary judgment of no infringement under the doctrine of
equivalents and remand.