NOTE: This disposition is nonprecedential. 

United States Court of Appeals 

for the Federal Circuit 

__________________________ 

ALCOHOL MONITORING SYSTEMS, INC., 

Plaintiff-Appellant, 

v. 

ACTSOFT, INC., OHIO HOUSE MONITORING 

SYSTEMS, INC., and US HOME DETENTION 

SYSTEMS AND EQUIPMENT, INC., 

Defendants-Appellees. 

__________________________ 

2010-1250 

__________________________ 

Appeal from the United States District Court for the 

District of Colorado in consolidated case Nos. 07-CV-2261 

and 08-CV-1226, Judge Philip A. Brimmer. 

___________________________ 

Decided: January 24, 2011 

___________________________ 

MICHAEL G. MARTIN, Lathrop & Gage, LLP, of Denver, 

Colorado, argued for plaintiff-appellant. With him on the 

brief were PHILLIPS S. LORENZO and JAMES E. DALLNER. 

KYLE B. FLEMING, Renner, Otto, Boisselle & Sklar, 

LLP, of Cleveland, Ohio, argued for defendants-appellees. 

With him on the brief were TODD R. TUCKER and 
ALCOHOL MONITORING v. ACTSOFT 2

NICHOLAS J. GINGO. Of counsel on the brief were RICHARD 

E. FEE and KATHLEEN M. WADE, Fee & Jefferies, P.A., of 

Tampa, Florida. 

__________________________ 

Before LOURIE, CLEVENGER, and MOORE, Circuit Judges. 

MOORE, Circuit Judge. 

Alcohol Monitoring Systems, Inc. (AMS) appeals the 

district court’s grant of summary judgment that defendants 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). Because the district 

court based its grant of summary judgment on an erroneous claim construction and genuine issues of material fact 

preclude summary judgment of infringement under the 

doctrine of equivalents, we affirm-in-part, reverse-in-part, 

and remand. 

BACKGROUND

The ’919 patent is entitled “Blood Alcohol Monitor” 

and discloses a device and methods of operating a device 

that securely attaches to a human subject and monitors 

blood alcohol levels by determining the alcohol levels 

expelled through a subject’s skin. The device is useful for 

monitoring the consumption of alcohol in individuals 

under house arrest or in alcohol rehabilitation programs. 

The liver metabolizes most of the alcohol ingested by 

a human. Water compartments in the skin, however, also 

absorb small amounts of alcohol, which the skin later 

emits through insensible perspiration. Measuring the 

alcohol levels expelled through a subject’s skin is known 
3 ALCOHOL MONITORING v. ACTSOFT

as transdermal alcohol monitoring. Transdermal alcohol 

levels are not the same as blood alcohol levels, which one 

measures from a blood sample using gas chromatography. 

However, “measuring the amount of ethanol at a predetermined distance away from the subject’s skin . . . provides an indication of the relative amount of ethanol in 

the subject’s blood.” ’919 patent col.3 ll.27-31. 

One measures transdermal alcohol levels by sampling 

the air near a subject’s skin with a transdermal alcohol 

sensor. Id. col.6 ll. 48-66. The alcohol sensor creates an 

electrical current and the voltage of that electrical current 

is proportional to the amount of alcohol present in the 

sampled air. Id. col.6 ll.59-62. Through the use of conversion factors, one can convert this voltage and calculate 

a transdermal alcohol concentration (TAC) that approximates blood alcohol content (BAC). Id. col.11 ll.28-38. 

Claim 14 of the ’919 patent is at issue in this appeal: 

14. A method for monitoring the percentage of 

blood alcohol content of a human subject, 

said method comprising the steps of: 

(a) securely attaching an alcohol measurement device to the human subject 

using an attachment device; 

(b) storing an error indication if the human subject tampers with said measurement device or an error occurs 

within said measurement device; 

(c) measuring a percentage of alcohol expelled through the subject’s skin into 

said measurement device and storing 

a measurement result; 

(d) repeating steps (b) and (c) until a predetermined amount of time expires; 
ALCOHOL MONITORING v. ACTSOFT 4

(e) transmitting each of said measurement results and each of said tamper 

and error indications to said monitoring station; and 

(f) repeating steps (b) through (e). 

AMS markets the SCRAM device, which it considers a 

preferred embodiment of the ’919 patent. The SCRAM 

device not only measures the voltage produced by the 

alcohol emitted through the subject’s skin, but also converts the voltage measurement to a TAC value that 

approximates a percentage BAC.1 

On October 25, 2007, AMS asserted the ’919 patent 

against Actsoft and Ohio House for the sale of the House 

Arrest Solution (HAS) device. AMS later added U.S. 

Home as a defendant. The HAS device includes an ankle 

bracelet with a gas sensor that measures the voltage 

produced by the alcohol emitted through a subject’s skin, 

but does not calculate TAC or any other percentage. 

Every fifteen minutes, the HAS device takes four voltage 

measurements. The measurement result stored and 

transmitted by the HAS device is a scaled, average voltage reading calculated by a proprietary formula. Defendants refer to this calculated variable as “fValc,” which is 

a decimal average of the four voltage measurements. 

On December 30, 2008, defendants Actsoft and Ohio 

House moved for summary judgment of noninfringement 

and invalidity. On April 27, 2009 the district court issued 

an Order Regarding Claim Construction. Alcohol Monitoring Sys. Inc. v. Actsoft, Inc., Civil Action Nos. 07-cv-

 1 BAC is the amount of alcohol per fixed unit of 

blood and is normally defined as grams of ethanol per 

deciliter of blood (g/dL). This BAC is also defined as a 

percentage of the weight of ethanol per volume of blood (% 

w/v). 
5 ALCOHOL MONITORING v. ACTSOFT

02261, 08-cv-01226-PAB-MJW, 2009 WL 1120113 (D. 

Colo. Apr. 27, 2009) (Markman Order). The district court 

construed the disputed terms, two of which are at issue in 

this appeal – steps (c) and (e). Id. at *7. 

The district court held that step (c) of claim 14 required “the measurement of the amount of alcohol being 

emitted from an individual’s skin and the calculation of a 

percentage of blood alcohol content.” Id. The district 

court noted that the specification consistently referred to 

the invention as measuring blood alcohol content. Id. at 

*4-5. For example, the specification alternatively describes the invention as: a “method to passively test the 

blood alcohol content of a human subject;” “perform[ing] 

testing which indicates the blood alcohol content of a 

human subject;” and “provid[ing] for the continuous 

monitoring of a subject’s blood alcohol level by measuring 

the level of ethanol that has been expelled through the 

subject’s skin.” Id. at *5. The district court noted that 

the specification contains an example of how to calculate 

blood alcohol content after measuring a sample with a 

sensor that measures voltage. Id. at *4-5. 

The district court further found that its construction 

was supported by the preamble of claim 14: 

Step (c) contemplates more than the mere ascertaining of the amount of alcohol emitted from a 

person’s skin. Some calculation or series of calculations must take place which lead to the identified percentage. It is true that Step (c) does not 

indicate literally that the calculation undergone at 

this stage arrives at a measure of blood alcohol 

content. However, . . . Claim 14 as a whole does 

indicate that such a calculation is to occur; its 

preambulatory language explains that the invention consists of a ‘method for monitoring the per-
ALCOHOL MONITORING v. ACTSOFT 6

centage of blood alcohol content of a human subject.’ It is axiomatic that a device could not ‘monitor’ one’s percentage of blood alcohol content 

without first determining what that percentage is. 

Id. at *4 (internal citations omitted). The district court 

also determined that its construction was supported by 

the testimony of AMS’s expert J. Robert Zettl who stated 

that the term “percentage of alcohol” in step (c) meant 

“blood alcohol concentration.” Id. at *4. 

The district court construed step (e) to require 

“transmitting every indication from Step (b) and every 

measurement from Step (c) in a way that the individual 

indications and measurements are separately identifiable.” Id. at *7. The district court relied on a dictionary 

defining “each” as “being one of two or more distinct 

individuals having a similar relation and often constituting an aggregate.” Id.

On April 28, 2009, the district court, ruling from the 

bench, granted the motion for summary judgment of 

noninfringement. Alcohol Monitoring Sys. Inc. v. Actsoft, 

Inc., Civil Action Nos. 07-cv-02261, 08-cv-01226-PABMJW, Document Number 210 at 10 (D. Colo. Apr. 28, 

2009) (Opinion). The district court noted that AMS 

conceded that literal infringement was not possible given 

the court’s claim construction because the HAS device 

does not calculate a percentage of BAC. Op. at 5. The 

district court also held that the HAS device did not infringe under the doctrine of equivalents, because the “use 

of an alcohol sensor that provides nothing more than a 

voltage output equivalent to the amount of alcohol emitted from the subject’s skin is not the substantial equivalent of calculating a percentage of blood alcohol content.” 

Op. at 8. The district court determined that measuring 

the voltage alone is neither the substantially same func-
7 ALCOHOL MONITORING v. ACTSOFT

tion nor yields the substantially same result as determining a percentage of BAC. Op. at 8-9. 

AMS appeals, challenging the court’s claim construction and judgment of noninfringement. We have jurisdiction pursuant to 28 U.S.C. § 1295(a)(1). 

DISCUSSION

Infringement, either literal or under the doctrine of 

equivalents, is a question of fact. IMS Tech., Inc. v. Haas 

Automation, Inc., 206 F.3d 1422, 1429 (Fed. Cir. 2000). 

An infringement analysis is a two-step inquiry: first the 

court must construe the claims, and second the court 

must apply the properly construed claims to the accused 

device. See, e.g., Acumed L.L.C. v. Stryker Corp., 483 F.3d 

800, 804 (Fed. Cir. 2007). We review both the district 

court’s grant of summary judgment of noninfringement 

and its underlying claim construction de novo. Laryngeal 

Mask Co. Ltd. v. Ambu A/S, 618 F.3d 1367, 1370 (Fed. 

Cir. 2010). “Summary judgment is appropriate when 

there is no genuine issue as to any material fact and the 

moving party is entitled to judgment as a matter of law.” 

Immunocept, L.L.C. v. Fulbright & Jaworski L.L.P., 504 

F.3d 1281, 1286 (Fed. Cir. 2007). In making this determination, this court views the record in the light most 

favorable to the non-moving party. See Anderson v. 

Liberty Lobby, Inc., 477 U.S. 242, 255 (1986). 

I. Claim Construction 

Generally, we give claim terms their ordinary and 

customary meaning, which is the meaning a person of 

ordinary skill in the art would give to the term at the time 

of invention when read in the context of the specification 

and prosecution history. See Phillips v. AWH Corp., 415 

F.3d 1303, 1313 (Fed. Cir. 2005) (en banc). 
ALCOHOL MONITORING v. ACTSOFT 8

A. Step (c) 

AMS argues that step (c) does not require the “calculation 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 vitality to the claim.” See, e.g., Am. Med. Sys., Inc. v. Biolitec, 

Inc., 618 F.3d 1354, 1358 (Fed. Cir. 2010) (internal citations 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 percentage of blood alcohol” is such a descriptive name and does 

not additionally limit the scope of the claims. 

Furthermore, the district court’s construction of step 

(c) is difficult to reconcile with the fact that devices that 

measure alcohol emitted through the skin do not actually 

calculate a BAC, but instead calculate a TAC, which 

approximates BAC. The plain language of the claim, 

“percentage of alcohol expelled through the subject’s 

skin,” indicates that the measurement is not BAC, which 

is only measured by a blood sample, but instead is TAC. 

Indeed, Defendants admit that the claimed method calculates TAC, a percentage that provides an indication of 

BAC. Therefore, to the extent the claim requires a calculation of a percentage, that percentage only approximates 

BAC (e.g., TAC). 

However, AMS further contends that the term “percentage” does not require any calculation, but instead is a 

“percentage of alcohol expelled through the subject’s skin 
9 ALCOHOL MONITORING v. ACTSOFT

into said measurement device.” In other words, AMS 

contends that the term refers to the measured sample, 

which is not all of the alcohol expelled through the subject’s skin, but only the “percentage” that enters “into said 

measurement device.” 

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 

the body. 

Because AMS’s proposed construction is not quantifiable, 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 measurement 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. 
ALCOHOL MONITORING v. ACTSOFT 10

B. Step (e) 

AMS contends that the district court improperly construed step (e) to require transmitting “in a way that the 

individual indications and measurements are separately 

identifiable” based solely on the HAS device and the 

Defendants’ noninfringement arguments. AMS further 

argues that the district court’s construction is inappropriate because it confuses “measurement” with the claimed 

“measurement result.” Defendants argue that the district 

court did not construe step (e) solely in light of the HAS 

device, but instead relied on the plain meaning of “each.” 

We agree with AMS that the district court appears to 

have conflated the measurement of a percentage and the 

claimed “measurement result.” Step (e) requires “transmitting each of said measurement results and each of said 

tamper and error indications to said monitoring station.” 

We note that this “measurement result” may or may not 

be the same as the measured “percentage” of step (c). The 

claim does not require the storage and transmission of 

“said percentage” but instead introduces a new limitation: 

“a measurement result.” While the claimed “measurement result” could be the calculated “percentage” it could 

also be an indicator that the human subject has consumed 

alcohol or any other result capable of storage and transmission. These are two separate limitations and may or 

may not include the same information. Therefore, properly construed step (e) should refer not to a “measurement” but instead to a “measurement result.” 

Regarding the “separately identifiable” language of 

the district court’s construction, the district court clearly 

relied on the plain meaning of “each” and not the accused 

device as AMS alleges. We agree with the district court 

that the plain meaning of “each” is defined as “being one 

of two or more distinct individuals having a similar rela-
11 ALCOHOL MONITORING v. ACTSOFT

tion and often constituting an aggregate.” Markman 

Order at 13 (citing Merriam-Webster’s Collegiate Dictionary 390 (11th ed. 2007)). Thus, step (e) as properly construed requires transmitting every measurement result

from step (c) in a way that the measurement results are 

separately identifiable.” 

II. Infringement 

“To prove literal infringement, the patentee must 

show that the accused device contains every limitation in 

the asserted claims.” Mas-Hamilton Grp. v. La-Gard, 

Inc., 156 F.3d 1206, 1211 (Fed. Cir. 1998). To find infringement under the doctrine of equivalents, any differences between the claimed invention and the accused 

product must be insubstantial. Graver Tank & Mfg. Co. 

v. Linde Air Prods. Co., 339 U.S. 605, 608 (1950). One 

way of proving infringement under the doctrine of equivalents “is by showing on a limitation by limitation basis 

that the accused product performs substantially the same 

function in substantially the same way with substantially 

the same result as each claim limitation of the patented 

product.” See, e.g., Crown Packaging Tech., Inc. v. Rexam 

Beverage Can Co., 559 F.3d 1308, 1312 (Fed. Cir. 2009). 

It is undisputed that the HAS device does not calculate TAC or any percentage that approximates BAC, but 

merely measures voltage. Therefore, under the proper 

claim construction of step (c), the HAS device does not 

literally infringe claim 14 of the ’919 patent. 

With regard to the doctrine of equivalents, AMS argues that the district court failed to provide step (c) with 

any equivalents, because it required a calculation of a 

percentage that is included in the literal scope of the 

claims. AMS argues that this is reversible error, because 

a reasonable jury could conclude that the HAS device 

infringes under the doctrine of equivalents because its 
ALCOHOL MONITORING v. ACTSOFT 12

quantitative voltage measurement is equivalent to a 

calculation of a percentage TAC. AMS contends that both 

the measured voltage and the calculated percentage 

increase with increased alcohol consumption. AMS argues that to convert the measured voltage in the HAS 

device to a percentage of alcohol one must only use a 

simple mathematical equation. Thus, AMS argues that 

the only difference between the measured voltage and a 

calculated percentage of alcohol is the unit of measurement. 

Defendants argue that voltage is not substantially the 

same result as obtaining a percentage TAC. Defendants 

contend that the ultimate goal of transdermal alcohol 

monitoring is to obtain an approximate BAC and voltage 

alone, without more, is insufficient to calculate TAC. 

Defendants contend that even if there is a simple formula 

or algorithm to convert the HAS device’s voltage to a 

percentage TAC, there is no evidence that the HAS device 

performs such a calculation. 

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. 

Defendants argue that they are separately entitled to 

summary judgment of noninfringement because the HAS 

device either does not perform step (d) or step (e). We 

decline to address these arguments for the first time on 

appeal. See Superguide Corp. v. DirecTV, Inc., 358 F.3d 

870, 884 (Fed. Cir. 2004) (declining to address infringement theories not addressed by district court’s summary 

judgment decision). Now that we have properly construed 
13 ALCOHOL MONITORING v. ACTSOFT

the disputed terms, the parties will be in a better position 

to brief these issues to the district court. 

CONCLUSION

For the reasons discussed above, we affirm the district court’s grant of summary judgment of no literal 

infringement, reverse the district court’s grant of summary judgment of no infringement under the doctrine of 

equivalents and remand. 

AFFIRMED-IN-PART, REVERSED-IN-PART, AND 

REMANDED 

COSTS

Each party shall bear its own costs.