Quantitation

of energy

by infrared Melanie

thermography13

Shuran

and

Ralph

A Nelson

objective

of this

ABSTRACT

The

frared thermography IRT images were

(IRT) digitized

was computed;

heat

evaporation were

were

standing

loss

measured

caused

calculated the

by

IRT

feet; was

receiving

jects,

after

a constant

eating,

as predicted measured

the

by an increase was concluded

KEY

Infrared

WORDS indirect

ignored.

Total

different

from

of energy.

of response

to IRT

and

beings.

Am

thermography,

energy

subjects

Nineteen

of Illinois.

University

method

for

sub-

with

indirect pitalized

calorimetry postsurgical

Second,

the heat

the

pattern

loss

(by

quantity

of heat

of heat after

production

(by

a stimulus

and

Postsurgical

ankle

subjects

Twenty

patients

were

recruited

from

the

services

of Colon

2) be receiving (oral temperature:

Nutr

#{176}C), and ied while

losses

obtained

was

fol-

clothing

if desired,

food for at least enteral nutrition

of feeding

the

by restricting

underwear,

J C/in

heat

IC)

maximized

Hospital. had 1) no

in

from

5 consecutive days, (TPN), 3) be afebrile

4) be able receiving while on

receiving were

the

basis

lowing

nutritional

amino

acid

support and

varying

were

emulsion

at 20-62

I

From

versity 2

infused

par37.7

phy-

conditions,

or 5.0%

solution (3.4 or 2) 3.5% dextrose, Abbott

patients.

Amino

of

90-100

crystalline

Laboratories,

North

kcal dextrose or 5.0% crys-

and 10% or 20% Laboratories). All

acid mL/h

vitamins to meet and and

(1). the

dextrose iv lipid

mL/h.

Sciences;

of Illinois

attending

medical

trace elements and attending physicians

at a rate

the Department

Supported

1) 3.5% Abbott

5-35% (Liposyn,

ofthe

requirements

of Nutritional

status,

regimens:

standard altered by

solutions

by the patients’

5-35% dextrose Abbott Laboratories),

were

compared

total

infusion.

(Aminosyn,

included

in healthy

eliof

needs as dictated by the results of the Patients were placed on one of the fol-

talline amino acid solution, intravenous lipid emulsion Electrolytes

considerations

the

prescribed of nutritional

solution

Chicago, IL) monohydrate/g,

To meet oral intake

to stand unassisted. Eight patients were studintravenous (iv) lipid emulsion and 12 were

not

solutions

therapies

and methods

Ethical

was

appropriate

and Rectal Surgery at Carle Foundation gibility criteria, patients had to have

subjects.

Subjects

exposure

by IRT. It can be used

(IC) in healthy, fasting humans, and in hospatients in a steady state ofenergy infusion. IRT)

on

IC were

used for measuring focused on adapting

production

based

socks.

To judge the accuracy of IRT, two comparisons were First, the quantity of heat loss obtained from IRT was

compared

was

serof the

skin

metabolism,

quantitating

eligibility

of

the outpatient population

T-shirt,

and estimated caloric nutritional assessment.

as a noninvasive

with

Subject

IL,

the Departments

to shorts,

TPN

is commonly This study

from

collection,

studied

(IRT) of objects.

Champaign-Urbana,

recruited

deterpa-

calorimetry

Infrared thermography surface temperatures

in the

were

values

Introduction

humans. made.

living

They

Medical Research at the Carle Foundation, vices of Carle Clinic, and from the student

sicians

IRT

individuals

participated.

lowing criteria: 1) 18 y of age, 2) normotensive, and 3) normothermic (body temperature 37.7 #{176}C). To facilitate IRT data

Heat loss followed

as measured method

Healthy

area

heat

In healthy

direct calorimetry data. first, 30 mm postprandially,

in human

in-

and

calorimetry (IC) and in postsurgical

in heat loss at 60 mm that IRT as a noninvasive loss

to adapt

convection,

was

indirect subjects

patterns

to quantitate heat 199 l;53: 136 1-7.

loss,

heat

infusion

from previous by IC increased

was

these data. Because subjects a small amount of heat was

significantly

from simultaneous in fasting healthy

tients

heat

this

not

study

heat loss in human beings. body surface temperature

by radiation,

by using procedure

the

through

calculated minations

to measure and a mean

losses

during

conducted

expenditure

and

of Research, Carle Foundation; the Division the Department oflnternal Medicine. Uni-

at Urbana-Champaign. in part

by grant

83507

from

Abbott

Laboratories,

North

Chicago, IL. The

use ofhuman

Institutional University from each .4m

J C/in

Review of Illinois. subject. Nuir

subjects Boards Written

1991;53:l361-7.

was reviewed

and

of the

Foundation

Carle

informed

Printed

approved

consent

in USA.

by the and

was

the

obtained

© 1991 American

Downloaded from https://academic.oup.com/ajcn/article-abstract/53/6/1361/4732401 by University of Minnesota Law Library user on 27 March 2018

Society

3

Address

Park

Street,

reprint

requests

Urbana,

Received

June

Accepted

for publication

for Clinical

to RA

Nelson,

Carle

Foundation,

6 1 1 West

IL 61801. 19,

Nutrition

1989. September

12.

1990.

1361

1362

SHURAN

To facilitate without

data

disrupting

collection, routine

skin

exposure

postoperative

was

nursing

AND

maximized

care

is converted

or unduly

embarrassing the patient. Subjects wore a hospital gown with or without undergarments. As a result oftheir medical conditions, some patients were required to wear antiembolism stockings. Anthropometry

Weight

was measured

Detecto

scale

to the nearest

(Detecto-medic,

0. 1 kg on a balance-beam

Brooklyn,

NY).

Height,

measured

with meter sticks, was recorded to the nearest 0. 1 cm. Ideal body weight (IBW) was obtained from the 1983 Metropolitan Life Insurance Tables on the basis of body frame size (2). To determine body surface area, the 19 circumference and length mensurements ofDuBois (3) were obtained by using a fiberglass tape with values recorded to the nearest 0. 1 cm. A nutritional diagnosis designated whether patients were within normal limits or had marasmus, kwashiorkor, or marasmus-kwashiorkor (2). Study

protocol

Healthy subjects. Subjects arrived at the Medical Research Center at the Carle Foundation Hospital at 0800 the morning of the study after fasting for 10-14 h. To minimize environmentally induced alterations in metabolism, participants were instructed not to perform strenuous physical activity (running, biking,

etc) the morning

as caffeinated rested

ofthe

beverages

in a supine

study

or nasal

position

or to ingest decongestants.

on a hospital

bed

stimulants such Participants

for 20 mm.

Resting

energy expenditure (REE) was measured by IC, after which subjects sat for 10 mm before the initiation of the study. During this 30-mm period, it was anticipated that individuals would adapt to the environmental conditions in the room and dissipate any heat storage generated before reaching the study center. For the fasting

and

postprandial

studies,

IC measurements

were

NELSON

per-

formed at 0 (baseline), 30, 60, and 90 mm whereas IRT data were collected every 15 mm. Each IRT scanning series took - 1 mm to complete and consisted of recording the subject’s heatloss patterns, front and back, three times on videotape. On the second day of the study a test meal was fed. No cold or hot caffeinated beverages were consumed. Foods eaten were weighed or measured. Nutrient values for the test meal were as follows: (± SEM) 631 ± 5 kcal, 17 ± 2% protein, 46 ± 3% carbohydrate, and 37 ± 5% fat. The percentage composition ofthe test breakfast meal was similar to the usual consumption of each subject. Postsurgicalpatients. Patients were admitted to the study room

by a liquid

lunum detector television picture in the

nitrogen-cooled

mercury-cadmium-tel-

to an electrical ofthe thermal

field

of view

256 divisions

ranging

signal that is processed into a patterns (infrared thermogram) of the camera. A calibrated grey scale with in intensity

from

black

to white

is presented

across the bottom of the thermogram in normal scanning or in the viewing or recording mode. Each of the scale divisions represents a discrete temperature and thus provides a means for evaluating the relationship between the contrast in the display and the temperature differentials on the surface of the subject. To ensure that data collection occurs in the linear range of the camera, a 10 #{176}C scanning range, including 160 of the 256 grey levels located in the central portion of the calibrated scale is used.

Consecutive

of -0.06

grey

levels

#{176}C. Although

continuous

basis,

differ

in

the camera

it is not

temperature

by

is calibrated

possible

a value

internally

to directly

read

on a

temperature

from the system. Therefore, reference temperature data from three independent standards, or black bodies, were used to gencrate calibration curves comparing grey-scale values from the camera with temperatures recorded during the scanning of each subject. The temperatures chosen for the black bodies, 23-33 #{176}C, were comparable with the range of surface temperatures of human subjects measured in preliminary studies in our laboratory. Black-body temperatures were measured with surface thermistors (series 400, model 409A) attached to a telethermometer (series 400, model 42SC) and model 4002 12-channel switch box, all from Yellow Springs Instruments (YSI), Inc, Yellow Springs, OH. Ambient temperature was monitored with a YSI model 405 air temperature thermistor. Oral temperature was also obtained with a thermistor from the YSI series. All thermistors were independently calibrated to certified thermometers

that

and

dards dards).

met

the criteria

Technology

ofthe

(formerly

Correlation

National

the National

coefficients

for the resulting

Institute

of Stan-

Bureau

of Stan-

regression

equa-

tions were 0.98 and 0.99. A full-range mercurial barometer (Princo Instruments, Inc, Southamptom, PA) was used to measure barometric pressure, and relative humidity was obtained via a motor-driven psychrometer (Vista Scientific Corporation, Ivyland, PA) (4-6). Computer

analyses

ofIRT

data

thermal adaptation to environmental conditions. Once in the room, patients removed their robes and slippers and sat down. During the adaptation period, composition and rate of infusion

Infrared images of each subject’s heat-loss patterns were recorded on videotape with a VHS video player and recorder (VCR) (Canon, Lake Success, NY). For data analyses the tape was played from the VCR into a video frame store (Colorado Video, Inc, Boulder, CO), which digitized the infrared thermal image from each frame and simultaneously displayed the image on a black and white television monitor (Panasonic, Secaucus,

of TPN

NJ).

,.-45

mm

before

data

solutions

were

Patients stood front and back patient and the After scanning, sitting.

IRT

collection

to allow

an adequate

period

for

recorded.

for the IRT

scanning

procedure,

which

included

view. Three scannings were completed on each second scan was chosen later for data analyses. IC data were collected while the patient was

data

were

collected

before

and

after

IC measure-

ments.

Infrared The Bedford,

thermographic model MA)

525

system infrared

is a small,

light-weight

radiometer field

video

output

emitted

from

(Inframetrics,

instrument

signal.

that

The

the subject’s

pro-

aid of a VT240

and

RXO2

Champaign,

frozen

and

trieval,

software

stored

microcomputer

dual

IL), the frame

on a 20.32-cm programs

were

system,

disk drive floppy used

(Digital

chosen

PDP-l

for analysis

disk.

After

to remove

1

Equipment was

image

re-

the background

thermal patterns from the frame, leaving only the digitized front or back view ofthe subject. Another software subroutine tallied the number of pixels or picture elements contained in 0.5-#{176}C of the

lO-#{176}C study

area. From this information ature, including clothing,

infrared

computation

surface

to yield

Downloaded from https://academic.oup.com/ajcn/article-abstract/53/6/1361/4732401 by University of Minnesota Law Library user on 27 March 2018

the

Corporation,

divisions

imaging

duces a television-compatible radiation (8-12 zm) naturally

With

microprocessor,

ofradiative,

total

heat

range

over

a weighted was calculated convective,

loss. The

evaporative

and

the

mean and

total

body

surface

surface temperwas used in the

evaporative

component

heat

losses

is the sum

INFRARED of heat skin

losses

and

due

loss

heat-loss

component,

the

system

IRT

losses vection ties

diffusion

vapor was

ignored

data

were

while

of water

in expired

MA)

Datametrics,

was

0.2




of the

minus

that

between 74 and mean differences

from -6 to -9 kcal/h. and contributions to total and

evaporation

compared

a constant

were

calculation

with

increase

were normal

in heat

variation infusion

similar subjects,

loss

by evap-

between ofenergy

IC and than

was

subjects*

Infrared

calorimetry Energy

data

eating.

for 13, and marasmus-kwashiorkor for 5 subjects. Indirect calorimetry and infrared thermography. In both groups, there were no significant differences in energy expen-

oration equaling that of convection. Analysis oftrends indicated greater

in normal

IC

data were as follows: age 45 ± 4 y, height 170 ± 2 67 ± 4 kg, and percent ofideal body weight 104 ± 5. assessment showed normal values for 2, kwashiorkor

the

± 0. 1 #{176}C.

28.4

both

IRT.

Postprandially,

between

Although

IRT

after

36.2

expenditure

Indirect

not

postprandial

IRT

quotients

IC was

to

ranged

fasting

values showed throughout the

I).

#{176}C.

TABLE 1 Respiratory

a

radiation,

route

was no

when

mean

in each

± 0. 1 #{176}C and 28.2

expenditure

were compared with that by IC. However, that IRT data consistently exceeded IC 105 mm of study. The slight elevation of

diture

1). Oral

between

energy

measured

data IRT

by IRT

There

thermography.

in the total

data

mm

sig-

1 (the

vs infrared

difference

significant

statistically

significant

53% of the heat

ranged

body

statistically

quotients

not

on day

between

and

was

A total

subjects

tervals. Approximately 27% was convective, mean

change

studies. 19 control

respiratory

calorimetry

significant

and IRT increased significantly after eating, the times of occurrence were different. IC first showed a significant increase 30

However, the 76 IC measurements completed on day 2 showed that after eating, minute volumes ofexpired air, 02 consumption, and CO2 production were significantly elevated over baseline fasting concentrations at 30, 60, and 90 mm. These changes resulted in a significant increase in energy production as a result of food

NELSON

expenditure

Radient

Total

thermography Convective

Evaporative

kca//h

kca//h

Day 1

mm

Fasting,

0

Fasting,

15 mm

Fasting, Fasting, Fasting,

30 mm 45 mm 60 mm

Fasting,

75 mm

Fasting, Day 2 Fasting, Fed Fed,

0.88

± 0.02

76.1

-

0.86

± 0.02

79.2

-

0.83 0.83

0 mm

0.89

± 0.02

15 mm

Fed, 60 mm

0.92

± 0.02

78.5

0.02

77.1

±

±

1.1

15.6

±

1.0

22.7

±

1.1

15.7

±

1.0

82.5

±

4.2

44.0

±

1.2 1.1

15.7 15.8

1.0

± 4.1

80.6

±

4.2

1.1

15.5

±

79.4

±

3.9

1.0

15.6

± 5.3

81.0

± 4.1

22.8 ± 22.0 ± 22.1 ± 21.8 ± 22.3 ±

±

80.3

2.3 42.6 ± 2.2 42.9 ± 2.2 42.1 ± 2.1 43.2 ± 2.2

1.1

0.9 15.5 ± 0.8

± 4.2

81.9

± 4.5

43.7

22.6

1.3

15.6

5.7

±

5.3

-

-

±

0.02

88.5

±

5.3t

±

4.7t

-

± 0.02

88.2

-

0.83

22.7

± 2.3

-

-

Fed, 75 mm Fed, 90 mm Fed, 105 mm

± 2.2

43.8

-

-

0.93

43.6

± 4.3

±

77.6

-

Fed, 30 mm Fed, 45 mm

± 4.2

82.2

-

-

90 mm

81.9

± 6.2 -

-

± 0.02

86.8

-

± 4.5t -

1±SEM.

t

Significantly

different

from

fasting

values,

P