ANALYSIS OF GASTROINTESTINAL' MOTOR PROFILE BY ANALOGICAL AND NUMERICAL PROCESSING OF THE ELECTRICAL EVENTS

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ANALYSIS OF GASTROINTESTINAL’ MOTOR

PROFILE BY ANALOGICAL AND NUMERICAL

PROCESSING OF THE ELECTRICAL EVENTS

Lionel Bueno, A. Latour, C. Dardillat

To cite this version:

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ANALYSIS OF

GASTROINTESTINAL’

MOTOR PROFILE

BY

ANALOGICAL

AND NUMERICAL

PROCESSING

OF

THE

ELECTRICAL EVENTS

L. BUENO A. LATOUR C. DARDILLAT*

Laboratoire de Physiologie, Ecole Nationale Vétérinaire, 31076 Toulouse, France

*

Laboratoire de la Digestion des Ruminants, l. N. R.A. Centre de Recherches Zootechniques et Vétérinaires de Theix, 63110 Beaumont France

Gastrointestinal

motility

can be

chronically

investigated

by

recording

the muscular wall deformations

_using

strain gauges or the

rapid

changes

in the electrical

activity

of the smooth muscle cells at the

_origin

of their contractions

(Bass and

Wiley,

1965). Quantification of the

spiking activity

of the small intestine has been obtained

using

a conventional

_operational

amplifier integrator

circuit

_coupled

with a

sim-ple high-pass

filter (Latour, 1973).

Recently,

a more selective

integration

of the

spiking

acti-vity

at the

gastro-duodenal junction

has been achieved

_by

_using

a slow-wave

_excluding

device (S.W.E.D.) instead of filters

(Latour,

1978).

Finally,

the

preamplified

EMG

signals

( ±

3 V) are

_applied

to an

_integrator

circuit

comprising

either a

_simple

3 Hz filter or a

S.W.E.D. and the

_activity

is

plotted

at 20 sec.

intervals on a

_{potentiometric}

multi-channel recorder. The electrical events are recorded as

previously

described

(Ruckebusch,

1970). In

addition,

the

_signals

are either

_directly

analy-zed

by

a

_{microcomputer}

(MEK 6800 D2)

con-nected to the same

_{potentiometric}

recorder,

or

stored on an

_analog

_{tape recorder}

_(fig.

1 This

record is then fed into a PDS 6800

microcom-puter to

_give

the motor

_profile

on a TV screen

(fig.

11. ).

Analogic processing

In most cases

_(jejunum,

ileum and

colon),

a

simple

RC

_high-pass

filter (3 Hz, - 3 dB) is

sufficient to select the

_{spiking activity}

from slow-wave

potentials.

In the other cases

(antrum and

duodenum),

the

original signal

is

pretreated

with an

_adapted

S.W.E.D. The

S.W.E.D. circuit utilizes the _{constancy of}

phase-locking

or

_spike

bursts to slow waves

-spike

bursts occur within 0.2 to 3 sec. after the

return to the slow-wave isoelectrical line - to

create, locked to the slow wave, a window

phase

through

which

_signals

_maybe

_passed

to

the conventional linear

_integrator.

The

posi-tion of the window is fixed

by

the

_positive

deflection of the slow wave which serves as a

trigger

for the

delay

circuit.

Summation of selected

spiking

activity

was

obtained

_by

_using

an

_integrator

(A

200,

Teke-lec) short circuited at 20 sec. intervals

by

the

use of an electronic clock. The output was

connected to the

input

of a

_high

impedance

potentiometric

recorder,

and the output

signal

was calibrated in microcoulombs

_(!c).

The slow paper

speed

of the

_{potentiometric}

recorder related to the width of the

writing

pen induced a continuous X trace of the records

showing

the amount of electrical

activity

as

the area covered

_by

the pen.

Computer analysis

Quantification of the

_spiking

_activity

was

performed directly

on a low

_{configuration}

(3)

magnetic

tape recorder

_by

use of PDS M68 SAC 1 which has more

_{possibilities}

(16 K

memories).

a) Direct

analysis

(MEK 680IDD2J

The

_analysis

of number and duration of

spike

bursts of the small intestine was

perfor-med as indicated on the board

_operating

dia-gram

(fig.

2). After passage

through

P.I.A. fol-lowed

_by

a D/A converter, the two

_signals

corresponding

to the number and duration of

spike

bursts per 2 min. consecutive

periods,

were

displayed

on a multichannel

potentiome-tric recorder in addition to the

_analogic

inte-grated

EMG.

The

respective

presence of the two

_phases

of

_irregular

(ISA) and

_regular

(RSA)

spiking

activity

of the

_{migrating myoelectric}

com-plexes

indicated in another

_{potentiometric}

channel was more

accurately

determined

automatically

from the number of bursts than from

_{analogical analysis.}

b) Numerical

_processing

(M68 SAC 1)

The recorded EMG

_signal

from small intes-tine or colon

(Analog

7,

Philips) replayed

at a

higher

speed (x

8) was entered in a

digital-counter

_interfacing

and treated

according

to

its nature.

For the small intestine the number of

spike

bursts was counted at 1-min. intervals

indica-ting

the duration of each ISA and RSA

phase

which appear

progressively

on the control CRT

display

monitor (TV screen)

during

the EMG

display

(fig.

3).

The duration of total

spiking activity,

of ISA and RSA

phase analysis,

was

_printed

on a

teletype

at the end of the tape

replay

(4)

Colonic

electromyograms

present two _types

of

_{spiking activity, consisting}

of short

spike

bursts (0.2 to 3 sec.) located at one site (SSB)

and

_{long spike}

bursts (8 to 20 sec.)

propagated

over more than 20 cm (LSB1. The SSB

occur-red more

exactly

on the

_spiral

and terminal

colon,

and LSB in the

_proximal

colonic area in ruminants.

Identification of these two forms and the

analysis

of their

respective

presence is

obtai-ned from the EMG

_magnetic

tape record

replay

at

high speed

(x 8)

using

the M 68 SAC 1. In this case, the presence of SSB (e) and LSB ( * is detected each 20 sec indicated on

both scopes and

printed

on a

teletype

at a rate

of 15 min. per

line, quiescence

being

indicated

by

dots. At the end of each

line,

the PDS

_gives

the

_respective

duration of SSB and LSB

acti-vity,

as well as their total duration at the end of the

replay

i.e. for 12 h

_recording.

References

BASS P., WILEY J.N., 1965. Electrical and extraluminal contractile-force activity of the duodenum of the dog. Am. J. Dis., 10, 183-200.

LATOUR A., 1973. Un dispositif simple d’analyse quantitative de 1’61ectromyogramme intestinal

chronique. Ann. Rech. Vet., 4, 347-353.

LATOUR A., 1978. Quantitative analysis and measurement of myoelectrical spike activity at the gastro-duodenal junction. Ann. BioL anim. Bioch. Biophys., 18, 711-716.