MACRODUCT 
SWEAT COLLECTION
SYSTEM
instruction/service manual 
Model 3700 SYS y
p
o
C
M 2551-7 rev A 
COPYRIGHT 2004 WESCOR, INC 

ii

TABLE OF CONTENTS 
section 
INTRODUCTION 
1.1 User's Manual Overview ...................................................................... 3
1.2 To Our Valued Customers ................................................................... 4
1.3 Important User Information .................................................................. 5
1.4 System Components ............................................................................6
1.5 Webster Sweat Inducer ........................................................................8
1.6 Pilogel¨ Iontophoretic discs ................................................................. 12
1.7 Macroduct Sweat Collector .................................................................. 16
section 
2
SWEAT INDUCTION AND 
COLLECTION 
2.1 Inducing Sweat ..................................................................................... 21
2.2 Collecting Sweat .................................................................................. 27
2.3 Abbreviated Instructions ....................................................................... 33
section 
3
SWEAT ANALYSIS 
3.1 An overview to Sweat Analysis ......................................................... 37

TABLE OF CONTENTS 
section 
TROUBLESHOOTING 
AND MAINTENANCE 
4.1 Troubleshooting Procedures ............................................................. 41
4.2 Cleaning the Electrodes .................................................................... 44
4.3 Replacing Inducer Batteries .............................................................. 45
APPENDIX A 
Specifications ............................................................................................... 49
APPENDIX B 
Supplies and Replacement Parts ................................................................. 53
APPENDIX C 
A Perspective on the Sweat Test................................................................. 56
References ................................................................................................... 60

SECTION 1
INTRODUCTION

2

3SECTION 1INTRODUCTION 
This manual covers the complete laboratory procedure for the laboratorydiagnosis of cystic fibrosis through examination of sweat electrolyte con-
centration. The steps preliminary to sweat analysisÐsweat stimulationand collection, are accomplished using the Macroduct¨Sweat CollectionSystem.
1.1 User's Manual OverviewCAUTION!
Never attempt sweat collection until you arethoroughly familiar with the procedures and cau-
tionary information detailed in this manual.
Abbreviated instructions printed elsewhere areprovided for reference only and should not beused as a substitute for the complete informa-
tion contained in this manual.

Thank you for purchasing the Macroduct Sweat Collection System. We areconfident that this is the finest sweat testing system in the world. As theacknowledged world leader in sweat testing products for the laboratory diag-
nosis of cystic fibrosis, Wescor is dedicated to providing customer support inall aspects of the use of this product and sweat testing theory and practice.
From the beginning, our goal has been to identify problems in sweat testing,
delineate the precise cause of false diagnosis, and then to devise innovativesolutions. We have accomplished this with the added benefit of vastly simpli-
fying procedures while remaining within the strict boundaries of acceptableaccuracy.
Wescor is ready to help you resolve any difficulty with the operation or per-
formance of the Macroduct system. If you cannot resolve a problem usingthe information in this manual, please contact us.
Wescor Inc. 
459 South Main StreetLogan, Utah 84321-5294USATELEPHONE:435 752 6011TOLL FREE:800 453 2725FAX:435 752 4127E-MAIL:service@wescor.comWEBSITE:www.wescor.comPLEASE NOTE:
WescorÕs Authorized European Representative for matters relating to the MedicalDevice Directive is:
MT Promedt Consulting GmbHAltenhofstra§e 80D-66386 St. Ingbert, GermanyTel. +49 6894 581020Fax +49 6894 581021email info@mt-procons.comSECTION 1 
INTRODUCTION 
41.2 To Our Valued Customer

APPLICATION:
The Macroduct System is intended for laboratory use by qualified personnel forstimulation and collection of sweat for analysis in the diagnosis of cystic fibrosis. 
Anyone operating Macroduct must be thoroughly familiar with the proce-
dures and cautionary information detailed in this manual before attempting touse this equipment. 
SPECIFICATION OF SAFE USE:
Using this device in a manner not specified by Wescor, Inc may impair the safetyprotection designed into the equipment and may lead to injury. Do not use whereflammable anesthetic is present or in any oxygen-enriched environment.
STATEMENT OF ENVIRONMENTAL LIMITS:
This equipment is designed to be safely operated at 
5¡to 35 ¡C, maximum relative humidity 80%.
EXPLANATION OF SYMBOLS FOUND ON EQUIPMENT:
IRunOStopInternational Attention Symbol.
Calls attention to important information andinstructions in the userÕs manual.
Type BF equipment complying with Medical Equipment SafetyStandard EN60601-1.
Current Flow IndicatorLow Battery IndicatorSECTION 1INTRODUCTION 
51.3 Important User Information

SECTION 1 
INTRODUCTION 
1.4 System Components 
Supply Kit 
for 6 sweat tests 
12-Pilogel¨ Discs, 
6 - Macroduct Sweat 
Collectors 
6-Small Sealable 
containers 
Webster Sweat 
Inducer 
Nippers 
Velcro Electrode 
Attachment Strap 
(red) 
Velcro Electrode 
Attachment Strap 
(black) 
Sweat Dispenser 
Macroduct Strap, Extra 
Large (39 cm) 
Macroduct Strap, 
Large (25 cm) 
Macroduct Strap, Medium 
(18cm) 
Macroduct Strap 
Small (14 cm) 
Electrode Set 
6

SECTION 1
INTRODUCTION 
1.4 System Components 
CATALOG NUMBER 3700-SYS 
DESCRIPTION UNIT CATALOG NO. 
Webster Sweat Inducer 1 each Model 3700
Electrode Set 1 each 320566 
Electrode Attachment Strap (red) 1 each RP-044
Electrode Attachment Strap (black) 1 each RP-045
Supplies kit for 6 sweat tests (12-Pilogel¨ Discs, 1 each SS-032
6-Macroduct Sweat Collectors,
6-Small Sealable containers)
Sweat Dispenser 1 each RP-065
Nippers 1 each RP-066
Macroduct Strap, Small (14 cm) 1 each SS-128
Macroduct Strap, Medium (18 cm) 1 each SS-129
Macroduct Strap, Large (25 cm) 1 each SS-130
Macroduct Strap, Extra Large (39 cm) 1 each SS-131

8The Webster Sweat Inducer is an integral part ofthe Macroduct Sweat Collection System. Its designis based on years of clinical experience, research,
and product development, with patient safety andcomfort given paramount importance. It is a fullyautomatic unit featuring advanced electronic cir-
cuitry and many fail-safe and operator conve-
nience features.
How It WorksWhen the RUN/STOPswitch is moved to the ÒIÓ
position,a brief tone signals that external electrodecircuit resistance is acceptable and that the instru-
ment has begun to deliver iontophoretic current.
Current delivery is confirmed by a green CURRENTFLOW INDICATOR. The tone sounds again briefly atthe completion of iontophoresis.
Iontophoretic current rises to 1.5 mA during a 17-
30 second interval, remains at 1.5 mA for 5 min-
utes, then decreases in the final 6 seconds to zero,
at which time the instrument switches off. This"profiling" of iontophoretic current prevents thesensation of electrical shock that results when cur-
rent changes abruptly. The CURRENT FLOW indi-
cator is wired in series with the electrodes.
During the complete iontophoretic sequence, thetotal electrical charge delivered to the positiveelectrode is approximately 450 millicoulombs or 78millicoulombs/cm2. Due to impurities in the agar,
Pilogel discs contain sodium and other cations intotal molar concentrations approximately equal tothat of the pilocarpinium ion. These therefore com-
pete with each other for transport of electricalcharge which produces an approximately 50%
reduction in the amount of pilocarpine that wouldhave been delivered to the glands in the absenceof such salts. However, sufficient drug is transport-
ed to produce maximal sweat stimulation.
SECTION 1 
INTRODUCTION1.5 Webster Sweat Inducer3700WEBSTER SWEAT INDUCER3700WEBSTER SWEAT INDUCER

9FAULT CONDITIONSTo maximize safety, the inducer continuously mon-
itors the current. If an unexpected condition isdetected the current turns off and an alarmsounds. This alarm continues until you move theswitch to STOP(0). 
A fault condition can occur if one of the electrodesbecomes detached. An alarm may also be due tolow batteries, (see next page). See Section 4 formore detail of fault conditions and alarms.
SECTION 1INTRODUCTION1.5 Webster Sweat Inducer

10LOW BATTERIESThe alarm sounds if the batteries are low when theswitch is moved to RUN(I). In this case, the amberLOW BATTERY indicator will also be illuminated,
and the inducer will not start. The alarm continuesuntil the control switch is moved to the STOP(0)
position.
If batteries get low during iontophoresis, the instru-
ment completes the cycle using remaining powerin the batteries, but at the end of the cycle, thetone sounds and the LOW BATTERY indicatorflashes. To disable the LOW BATTERY alert, pushthe switch to the STOP(0)position. 
Replace batteries before attempting anotheriontophoresis cycle. See Section 4.3.
SECTION 1 
INTRODUCTION1.5 Webster Sweat Inducer3700WEBSTER SWEAT INDUCERLOWBATTERYCURRENTFLOWSTOP3700WEBSTERSWEATINDUCERRUN!
3700WEBSTER SWEAT INDUCER

11SECTION 1INTRODUCTION1.5Webster Sweat InducerWipe Stainless SteelElectrodesCheck for cracks in lead wires3700WEBSTER SWEAT INDUCERELECTRODESThe high-grade stainless steel electrodes requireonly minimal maintenance. This consists of clean-
ing them with purified water after each use so theywill be ready for the next procedure (See Section4.2). Lead wires should be periodically inspectedfor breaks or cracks in the insulation. If electrodewires, insulation, or the plastic electrode housingexhibit cracks or breaks the electrode set shouldbe replaced.
NOTE:
If you activate the run switch while the electrodesare not attached to the patientÕs limb, an ÒopencircuitÓ alarm will sound. To disable the open cir-
cuit alarm, push the switch to the STOP position.

12SECTION 1 
INTRODUCTION1.6 Pilogel¨Iontophoretic DiscsThe traditional reagent solutions for pilocarpineiontophoresis are pilocarpine nitrate and sodiumnitrate. These have been applied either toabsorbent fabric (such as gauze) or to discs ofthick paper that are then interposed between theelectrode surfaces and the skin. Such reagentreservoirs have always presented problems toboth operators and patients.
Pilogel iontophoretic discs were developed specifi-
cally to overcome these and other problems. Theyconsist of a solid agar gel that is 96% water, intowhich is dissolved 0.5% pilocarpine nitrate and atrace of antifungal compounds. 
The discs are approximately 6 mm thick and sizedto fit snugly into the standard Wescor recessedelectrodes. Pilogel is supplied in a resealable vialcontaining 12 discs intended for one-time use (suf-
ficient for 6 iontophoretic sweat stimulations).
Discs are used in both positive and negative elec-
trodes. Sweat stimulation occurs under the positiveelectrode, while the disc under the negativeelectrode completes the electrical circuit. 
The Pilogel system provides monumental improve-
ments in patient safety, efficiency of sweat stimula-
tion, and convenience to the operator.

13SECTION 1INTRODUCTIONEFFICIENT SWEAT PRODUCTIONReliable, uniform, gel-to-skin contact ensuresdelivery of pilocarpine over the whole skin area,
thus providing total gland stimulation and maximalsweat yield.
Despite being mostly water and presenting a "wet"
surface to the skin, Pilogel discs do not exude fluideven under the pressure applied during limbattachment. This eliminates any possibility of"bridging". Gel-fitted electrodes may be placed inclose proximity without risking a short circuit, agreat advantage when dealing with neonates.
Pilogel eliminates the need to apply gauze orpaper pads. The discs are immediately ready foruse. There is no need to prepare or store reagentsolutions. With Pilogel, the electrodes, once fitted,
require no further attention during iontophoresis.
1.6 Pilogel¨Iontophoretic Discs

14SECTION 1 
INTRODUCTIONENSURING PATIENT SAFETYThe Macroduct system represents a dramatic im-
provement in patient safety over previous sweatinduction and collection methods. 
Pilogel discs provide an air-free continuousconduction medium and even distribution ofcurrent over the stimulated skin area, reducingthe possibility of electrical burns to the skin.
The Pilogel disc fits snugly into the recess of theelectrode, preventing disc separation from theelectrode. This virtually eliminates any possibilityof a burn from direct metal-to-skin contact. 
BURNS DURING IONTOPHORESISThe Macroduct Sweat Collection System has be-
come perhaps the most frequently used system inhospitals and clinics worldwide. 
While the Macroduct system is clearly superior toprevious methods, burns during iontophoresishave not been totally eliminated. Based onreports from practitioners, we estimate a frequen-
cy of 1 burn in 50,000 iontophoretic procedures.
Burn descriptions vary from Òtiny black pinholes inthe skinÓ to Òcrater-like, third degree burns two tothree millimeters in diameter.Ó In most of thereported cases the children have exhibited nosign of pain or discomfort during iontophoresis,
and the burn was not discovered until theelectrodes were removedParents must be informed and allowed to read theÒInformation for ParentsÓ included with theMacroduct supply kit. You should also have themsign an appropriate release form before perform-
ing this procedure. 
If the procedures outlined in the manual arefollowed correctly, burns should be extremelyrare.
1.6 Pilogel¨Iontophoretic Discs

15We strongly recommend the following burnprevention procedures:
1Do not use Pilogel discs that have an unusu-
al appearance (fractures etc.). See Section 3.2Electrode strap pressure should promote firmcontact between the skin and the gel disc.
Straps should not be tight enough to crushthe disc between skin and electrode.
3Leave skin slightly wet after washing the areawhere the electrode will be attached 
(OR)
Add a drop of water to either the skin or thepilogel surface (after installation in theelectrode).
SECTION1INTRODUCTION1.6 Pilogel¨Iontophoretic DiscsNOTE:
Although these recommendations are designed toprevent burns during iontophoresis, there is noguarantee they will not occur. Any institution pro-
viding sweat tests should thoroughly explain thispossibility to parents and obtain a written waiverfrom them prior to iontophoresis. Besides limitingliability from an unfortunate incident, parents thuswarned can make an informed decision abouttesting their child and are less likely to be upset ifa burn occurs.

16SECTION 1 
INTRODUCTION1.7 Macroduct Sweat CollectorThe Macroduct Sweat Collector is a disposableplastic device witha shallow concave undersurface that covers the skin area previous-
ly stimulated by pilocarpine iontophoresis. The collection surface iscontoured such that when firmly applied to the stimulated area, theskin bulges into the concavity, leaving no air space. At the apex ofthe conical surface, a tiny orifice leads to a small-bore plastic tubeor duct, having an inside diameter of approximately 0.64 mm, andcoiled into a spiral.
The base of the sweat gland is 2 to 3 mm beneath the surface of theskin. Fluid secreted by the gland creates hydraulic pressure thatmoves the fluid upward through the sweat duct to emerge from theskin as sweat. When sweat surfaces beneath a Macroduct collector,
this same hydraulic pressure forces it into the air-free interface be-
tween the skin and the concave surface of the collector. Since thepressure of the skin against the collector surface is greatest at therim and decreases inwardly toward the center, the secreted sweat isdirected to the orifice and into the plastic "macroduct.Ó
After attachment, sweat becomes visible in the spiral tube ofMacroduct within one to four minutes, depending upon the relativeelasticity of the skin and the subject's sweating rate.
The emergent sweat is turned blue by contact with a small amount(²10 nanomoles) of blue water-soluble dye (FDC certified foodcolor) applied to the Macroduct collection surface. This allows easyassessment of the volume produced at any time during collection.
This dye does not interfere with sweat chloride assay bycolorimetry. The dye contributes slightly to the osmolality and sodi-
um content of the sweat sample. Even with a low sweat yield of only20 µL, this contribution will not exceed 1.5 mmol/kg or 1.0 mmol/L,
respectively, and is negligible.
The spiral collection tube capacity is approximately 85 microliters.
This is adequate for average sweat production levels (50 to 60microliters) in thirty minutes of collection. This volume is sufficientfor all current methods of sweat analysis (see Notes RegardingSweat Yield p.17).
At the end of the collection period, the collector must remain on thelimb until the pristine sweat specimen is removed by severing theplastic tube at its attachment point. See complete instructions inSection 2 before attempting this procedure.
NOTE:
For best results, the stimulated skin area should cover deep flesh such as rea-
sonably thick musculature. Thin skin sections overlaying palpable tendons orbony structures are not suitable as collection sites.
BLUE COLORED SWEAT

17Advantages of Macroduct(a) By preventing any exposure to an air space the collected sweat isnot subject to condensate error. 
(b) Evaporation of sweat can only occur at the advancing meniscus inthe plastic collecting duct. This has been found by measurement to pro-
duce a negligible loss of 0.1 microliters per hour.
(c) The operator can gauge the amount of sweat produced at any time,
a unique and unprecedented feature that eliminates guesswork indeciding the duration of the collection period.
(d) The patient has complete mobility during the collection period. (Thecollector can be over-wrapped with an elastic bandage to keep curiousyoung fingers from causing mischief.)
(e) Macroduct collects sweat passively and automatically, driven by thesame hydraulic pressure that causes sweat to move from the base ofthe sweat gland to the skin surface.
There is no ÒharvestingÓ procedure during which the integrity of thesweat specimen is liable to be compromised by human error or otherfactors.
Notes Regarding Sweat YieldTechnologists experienced with the Gibson and Cooke pad absorptionmethod of sweat collection often raise the question of the Ò100 mgRule,Ó or some variation, which requires a minimum sweat volume forthe analytical result to be valid. To the extent that such requirementswere imposed to mitigate the error possibilities of the pad absorptionmethod, they may be disregarded, since Macroduct collection is free ofsuch errors.
On the other hand, some authorities have suggested that the minimumyield rules were promulgated because low sweating rates are associat-
ed with anomalous electrolyte concentrations, and therefore may giverise to a misleading diagnostic result. In order to establish an equivalentminimum yield threshold for Macroduct, one must take into account thedifferences in electrode size (area) and the recommended collectiontimes for the two methods.
Applying these ratios shows that an average collection of 50 µL in 15minutes using Macroduct is equivalent to a yield, in terms of sweatingrate, of approximately 350 mg by the pad absorption method.
Conversely, the sweat yield with Macroduct corresponding to the Ò100mg RuleÓ is approximately 15 µL.
SECTION 1INTRODUCTION1.7 Macroduct Sweat Collector

18

SECTION 2 
SWEAT INDUCTION AND COLLECTION

20

21SECTION 2SWEAT INDUCTION AND COLLECTION1ASSEMBLE EQUIPMENT AND SUPPLIESMake certain everything is on hand for thecomplete procedure. In addition to the com-
plete Macroduct Sweat Collection Systemyou will need a supply of pure water, alcohol,
and cotton balls or gauze pads.
2INSPECT ELECTRODES AND CONNECTTO INDUCERClean the electrodes if necessary (seeSection 5.2). Check wires and insulation forcracks or fraying. Replace electrodes ifwires, insulation, or plastic housing arecracked or frayed.
Press the electrode plug into the jack on thesweat inducer panel. You must engage thepositive/negative alignment pins correctly todo so. Tighten the locking ring to secure theconnection.
2.1 Inducing SweatMACRODUCT¨
SupplyKitSS-032LOWBATTERYCURRENTFLOWSTOP3700WEBSTERSWEATINDUCERRUN!
3700WEBSTER SWEAT INDUCERELECTRODES3700WEBSTER SWEAT INDUCERDue to the possibility of an explosion, neverattempt iontophoresis on a patient receiving oxy-
gen-enriched respiratory therapy in an enclosedspace. With medical approval, remove the patientfrom that environment during iontophoresis.
WARNING!

223CLEAN THE SELECTED SKIN AREASThe positive (RED) electrode must beplaced correctly for successful sweat collec-
tion. Locate it on an area of skin with a highdensity of sweat glands for optimum sweatyield. The preferred site is the lower portionof the flexor aspect of the forearm. Thisgenerally has a very high density of sweatglands, provided the limb is not so small asto prevent proper attachment of theMacroduct collector.
If the limb is tiny, place the red electrode onthe upper portion of the flexor aspect of theforearm (nearer the elbow) or even theupper arm. If the entire arm is too small toattach the collector (such as a prematureinfant), use the inner thigh. In this case,
constrain the infant from flexing the kneeduring collection to avoid a loss of interfacebetween the skin and the collector.
Attach the negative (BLACK) electrode atany other convenient position on the arm, orto the leg (on the same side of the body).
NOTE:
Do not place the electrode so close to the 
wrist that tendons or bone are palpable just be-
neath the skin. Reasonably thick musculature isnecessary for a proper interface with theMacroduct collector.
SECTION 2 
SWEAT INDUCTION AND COLLECTION2.1 Inducing SweatREDELECTRODEREDELECTRODETINY INFANT PLACEMENT

The selected site must be free of breaks, fissures,
or observable abnormality in the skin. Thereshould be no sign of inflammation. Apart fromexacerbating the complaint, there is the possibilityof contamination of the sweat by serous exudates.
The area must be as wrinkle-free and hairless aspossible.
Clean the skin at the selected sites to remove dirt,
fatty material and loose dead cells, to minimize theelectrical impedance of the skin. To do this:
aSwab the area vigorously with alcohol,
then with plenty of purified water.
bLeave the skin wet where the Pilogeldisc is to be attached (OR):
Place a drop of water on the skin or onthe surface of the Pilogel disc just beforeattachment.
This will ensure uniform contact over the area 
and reduce the possibility of a burn.
NOTE:
Be sure that you are familiar with theprecautions found in Section 1.6.23SECTION 2SWEAT INDUCTION AND COLLECTION2.1 Inducing Sweat1SWAB WITH ALCOHOL2 SWAB WITH PURIFIED WATER

4INSTALL PILOGELDISCS ON BOTH ELEC-
TRODESPilogel discs have a diameter slightly largerthan the inside diameter of the electrode skirtto provide a tight fit. Be sure to press firmlyall around the outer perimeter of the disc toachieve uniform, air-free contact with theelectrode. This may shave small slivers of gelfrom the outside of the disc as it is seatedagainst the electrode. This is normal. 
Do not be concerned if the Pilogel disc has atendency to bulge away from the stainlesssteel electrode at the center. Attachment tothe limb will flatten it against the electrode.
Never attach an electrode to the skin without 
Pilogel. Direct skin-to-metal contact will burnthe patient. Refer to Section 1.6 for additionalinformation.
Pilogel discs should be refrigerated at 2 to 8 ¡C.
DO NOT FREEZE. Never use discs that havebeen frozen or that are cracked. 
SECTION 2 
SWEAT INDUCTION AND COLLECTION2.1 Inducing Sweat24WARNING!
WARNING!

25SECTION 2SWEAT INDUCTION AND COLLECTION5ATTACH THE ELECTRODES TO LIMBPlace each strap so that the stud of the elec-
trode protrudes through the rivet of the strap,
with the ÒhookÓ portion of the short tab facingupward, away from the skin. Secure the elec-
trode firmly so that the gel surface is pressedflat against the skin. There should be moder-
ate pressure to minimize discomfort, but donot tighten enough to crush the gel disc.
NOTE:
Individuals vary in their sensitivity to iontophoreticcurrent. Most subjects feel nothing more than aslight prickling sensation during iontophoresis. Ifa child complains or if an infant shows signs ofdistress, tighten the strap to increase pressureagainst the skin.
2.1 Inducing SweatELECTRODE STUD3700WEBSTER SWEAT INDUCER

LOWBATTERYCURRENTFLOWSTOP3700WEBSTERSWEATINDUCERRUN!
3700WEBSTER SWEAT INDUCER266ACTIVATE IONTOPHORESISPush the control switch to the RUN (I)posi-
tion and hold momentarily until you hear ashort Òbeep.Ó A steady tone indicates exces-
sive external circuit resistance, a break in theline, or weak batteries. If this occurs, movethe control switch to STOP (0)and correctthe fault condition before proceeding (Section4).
If everything is normal, the CURRENT FLOWindicator reaches full brightness in approxi-
mately 20 seconds, and diminishes in bright-
ness during the last 5 seconds of iontophore-
sis as the current is reduced to zero.
If the circuit is broken even briefly during ion-
tophoresis, current flow ceases and the alarmsounds. If this occurs, switch the inducer toSTOP (0). Check leads and electrodes for fis-
sures, breaks, etc. See Section 4 for com-
plete information.
3700WEBSTER SWEAT INDUCERSECTION 2 
SWEAT INDUCTION AND COLLECTION2.1 Inducing Sweat

271PREPARE MACRODUCT SWEAT COLLEC-
TOR DURING IONTOPHORESISOpen one end of the plastic wrapper andslide the Macroduct sweat collector slightlyout of the package and thread a Macroductstrap of suitable size through one slot so thatthe ÒhookÓ side of the strap faces away fromthe Macroduct collection surface. DO NOTTOUCH THE COLLECTION SURFACE. 
2REMOVE ELECTRODES AT COMPLETIONOF IONTOPHORESISIontophoresis proceeds automatically forapproximately 51/2 minutes after RUN is acti-
vated. At completion, an audible tone soundsbriefly and the instrument turns itself off.
Remove the negative (black) electrode firstand then clean the exposed area of skin.
Before removing the positive (red) electrode,
mark around the stimulated area with analcohol-based felt marker to ensure properplacement of the Macroduct sweat collector.
Remove the positive (red) electrode.
SECTION 2SWEAT INDUCTION AND COLLECTION2.2 Collecting SweatGRASP MACRODUCTWITH PLASTIC 
WRAPPERREMOVE THE BLACKELECTRODE FIRST3700WEBSTER SWEAT INDUCER

283CLEAN THE SKIN UNDER THE POSITIVE(RED) ELECTRODEClean the stimulated skin and the surround-
ing area thoroughly with purified water toremove salt, then blot dry. There should bea distinct redness under the red electrode.
Proceed to Step 4 immediately. 
4ATTACH MACRODUCT SWEAT COLLEC-
TOR FIRMLY TO LIMBApply the concave surface of the Macroductcollector precisely over the area of skincontacted by the Pilogel disc. (The red-
dened area of skin will generally be largerthan the sweat-stimulated area.) 
Thread the free end of the strap around thelimb and through the opening. Then tightenthe strap until the collector is very firmlyattached, with strap pressure pulling asevenly as possible from each end of thecollector. 
Check for collector displacement duringattachment, and adjust if necessary.
SECTION 2 
SWEAT INDUCTION AND COLLECTION2.2 Collecting Sweat

29If a child attempts to disturb the collector,
overwrap the device with an elastic ban-
dage.
For neonate sweat collections, where thelimbs are extremely small, overwrap thecollector firmly with a 2 or 3 inch-wide elas-
tic bandage. This ensures a continuous andfirm contact between the collector and theskin, and greatly improves the probability ofa successful collection. 
Macroduct allows you to visually assesssweat production at any time by referenceto the spiral tube calibration diagram. A 30minute collection time usually yields 50-60microliters of sweat, although varianceamong individuals is extremely wide. Youcan vary collection time to maximize thesweat yield, but with most individuals, verylittle additional sweat can be collected after45 to 60 minutes.
BLUE COLORED SWEATSPIRAL TUBE 
CALIBRATION DIAGRAMSECTION 2SWEAT INDUCTION AND COLLECTION2.2 Collecting Sweat

305REMOVE AND STORE SWEAT SAMPLEFOLLOW THESE INSTRUCTIONSCLOSELY:
aRemove the protective transparentcover by inserting a pointed tool intoone of the cut-out sections and pryingupward. (The nippers supplied with theMacroduct system will work well.)
bInsert the blunt needle approximately5 mm into the open end of theMacroduct microbore tubing using atwisting motion (see illustration).
Alternatively, lift the open outer end ofthe micro-bore tubing and pull one ortwo inches of the tube free from theadhesive base before attaching thetube to the blunt needle of the syringe.
Position the plunger at mid pointbeforeinserting it into the tubing. 
Do not squeeze the dispenser orsyringe body or move the syringeplunger at any time during attachmentor during the following procedure.
NOTE:
The following procedure must be done 
while the Macroduct collector is still firmlystrapped to the limb. Removing thecomplete device before detaching the tub-
ing may create a vacuum that will draw thecollected sweat from the tubing andseriously reduce sample volume.
NOTE:
Inadequately tightened collector straps can be 
detected simply by pressing the collector veryfirmly against the skin. If the advancing menis-
cus of sweat in the spiral tube moves by morethan 2-3 millimeters, attach the strap morefirmly.
SECTION 2 
SWEAT INDUCTION AND COLLECTION2.2 Collecting SweatUSE TWISTING MOTION WHILEINSERTING BLUNT NEEDLE INTO THEEND OF THE MICRO-BORE TUBING. 

31cGrasp the tubing where it is attachedto the needle and pull the tubing awayfrom the collector body until the tubingis completely uncoiled and extendingoutward from the point of attachment.
Use the provided nippers to sever thetube as close as possible to the collec-
tor surface. 
dImmediately after severing the tubing,
carefully draw the sweat into the tubeone or two inches. This is to preventany loss of sweat from the cut end dueto expansion of air in the syringe body.
It also allows you to cut-off the tightlycoiled end of the microbore tubing foreasier handling.
OR 
If using the Sweat CheckªAnalyzer,
attach the end of the tube to the SweatChek intake for analysis. Refer toinstructions in the Sweat-Chek instruc-
tion manual.
e Expel the sweat specimen into the cupand immediately install the cover toprotect the specimen.
SECTION 2SWEAT INDUCTION AND COLLECTION2.2 Collecting SweatHOLD THE TUBING WHERE ITATTACHES TO THE SYRINGENEEDLE

SECTION 2 
SWEAT INDUCTION AND COLLECTION 
2.2 Collecting Sweat 
6 
REMOVE AND DISCARD COLLECTOR 
BODY 
Detach the collector body from the patientÕs 
limb. Retain the strap, and discard the collector 
body. 
7 
CLEAN THE ELECTRODES 
Remove and discard the Pilogel discs. 
Clean the electrodes with purified water and 
wipe dry. See Section 4.2. 

SECTION 2 
SWEAT INDUCTION AND COLLECTION 
2.3 Abbreviated Instructions 
CAUTION! 
These instructions are intended for reference only. Never 
attempt sweat induction and collection until you have read 
and thoroughly understand the complete procedures detailed 
in the instruction manual. 
1 ASSEMBLE EQUIPMENT AND SUPPLIES 
2 INSPECT ELECTRODES AND CONNECT TO 
INDUCER 
3 CLEAN THE SELECTED SKIN AREAS 
4 INSTALL PILOGEL DISCS IN BOTH ELECTRODES 
5 ATTACH THE ELECTRODES TO LIMB 
6 ACTIVATE IONTOPHORESIS 
7 PREPARE MACRODUCT SWEAT COLLECTOR 
DURING IONTOPHORESIS 
8 REMOVE ELECTRODES AT COMPLETION OF 
IONTOPHORESIS 
9 CLEAN THE SKIN UNDER THE POSITIVE (RED) 
ELECTRODE 
10 ATTACH MACRODUCT SWEAT COLLECTOR 
FIRMLY TO STIMULATED SKIN SITE 
11 REMOVE AND STORE SWEAT SAMPLE 
12 REMOVE AND DISCARD MACRODUCT RESIDUE 
13 CLEAN ELECTRODES 
33 

34

SECTION 3 
SWEAT ANALYSIS
35

36

37SECTION 3SWEAT ANALYSIS3.1 An Overview to Sweat AnalysisThe procedures described up to this point inthe manual provide the laboratorian with anundiluted sweat sample. By virtue of the specif-
ic safeguards against condensation and evap-
oration error, the sample is fully representativeof the patientÕs secretion and is therefore avalid specimen for analysis.
Sodium and/or Chloride AnalysisThese are the traditional sweat test analytes.
Sodium may be measured on Macroduct sam-
ples by adding an aliquot of the sweat sample(5 or 10 µL) to an appropriate volume of lithiumsulphate diluent and directly aspirating thissolution into a flame photometer that does notautomatically predilute. Sodium assay in itselfis not a reliable method in CF diagnosis,
because there is some overlap between nor-
mal and abnormal groups. It is usually per-
formed together with chloride, which has in thepast been determined using micro-titration withmercuric nitrate, an old method that requiresprohibitively large sample volumes for accept-
able accuracy. In recent times coulometrictitration requiring as little as 10 µL is oftenused. Ion-specific electrodes can be employedbut these usually require sample dilution to apoint where sensitivity is compromised. A sim-
ple colorimetric method is available thatrequires only 5 µL of undiluted sweat, and isnot affected by the minute amount of dye thatis present in Macroduct specimens.
OsmolalityA modern approach to diagnostic sweat analy-
sis that is more rapid, and more sensitive is themeasurement of osmolality using the WescorVapro¨Vapor Pressure Osmometer. Thisinstrument can provide an osmolality value ona little as 5 µL of undiluted sweat within 1.5minutes. Since osmolality indicates total soluteconcentration, which in sweat is made upalmost completely of electrolytes, it provides aconvenient single-measurement assessment ofsweat electrolyte level. Extensive trials withhospital patients have shown that the normalrange in children is approximately 50 to 150mmol/kg and the CF patients show values inexcess of 200 mmol/kg with an average of 270mmol/kg.
Electrical ConductivityWescorÕs Sweat Chek SweatªConductivityAnalyzer was designed to measure conductivi-
ty of Macroduct collected samples. Field test-
ing in clinics in the U.S.A and in the UnitedKingdom, testify to its simplicity, economy, andaccuracy in the diagnosis of cystic fibrosis. Theresults show clearly that conductivity, osmolali-
ty, and chloride have equal capacity to distin-
guish between normal and CF subject groups,
and are therefore equivalent as diagnostic indi-
cators. 
A detailed account of the nature of sweat con-
ductivity, the clinical trial results, and its statusin the international clinical laboratory scene ispresented in the Sweat-Chek UserÕs Manual.

38

SECTION 4
MAINTENANCE AND
TROUBLESHOOTING

40

41SECTION 4MAINTENANCE ANDTROUBLESHOOTINGAside from electrode cleaning, there is no regular periodic maintenance required in the Model3700 Webster Sweat Inducer.
If the system appears to malfunction, use the following information to identify and remedy theproblem.
SYMPTOMPROBABLE CAUSE/SOLUTIONNothing happens whenHigh circuit resistance (will be accompanied byswitch is pushed to RUN(I).an audible alarm). Completely dead batter-
ies. Check and replace if necessary.
Low battery light comes on and Low batteries. Replace batteries. 
alarm sounds when switch is pushed to RUN.See Section 4.3.
Alarm alternates from high to low pitch.Open Circuit. Make sure the electrodes are 
clean and unmarked. If necessary, clean or 
replace electrodes. See Section 5.2.
Make sure electrodes are strapped secure-
ly to the patientÕs limb. If alarm continues, 
arrange a short circuit at the inducer con-
nector by holding the two electrodes (with 
Pilogel disks installed) against each other. ThePilogel disks should be facing each other and 
touching. If the unit still does not operate, 
check electrodes and wires for open connections. If the inducer will not function with the 
connector shorted, return it to Wescor for 
service.
Alarm with steady tone.High skin resistance. Since the inducer has a 
fixed limit for acceptable resistance, try using 
another area of skin that may offer lowerresistance, or scrub the skin vigorously to 
remove as much dead epithelial cell material 
as possible. See Appendix B.
4.1 Troubleshooting

42SYMPTOMPROBABLE CAUSE/SOLUTIONAlarm has multiple alternating pitches, Overcurrent indication. Do not use 
much like a siren.inducer until it has been checked. 
Return to Wescor for service if needed.
LOW BATTERYlight flashes after ion-Low batteries. Replace batteries.
tophoresis and audio warning signal sounds.See Section 4.3.
If the malfunction has been traced to a faulty electrode, replacement parts can be ordered fromWescor (APPENDIX B).
If the malfunction has been traced to the electronics or cannot be isolated following the aboveprocedures, the inducer and electrodes should be returned to Wescor for inspection and repair. 
SECTION 4TROUBLESHOOTING AND MAINTENANCE4.1 Troubleshooting

43SECTION 4TROUBLESHOOTING AND MAINTENANCEDO NOT OPENthe case and attempt repairs dur-
ing the one year warranty period except whenauthorized and instructed by Wescor service per-
sonnel. To do otherwise wilI void the inducer war-
ranty. We strongly recommend that you return anymalfunctioning unit to Wescor for service evenafter the warranty has expired. Repairs made byelectronic technicians who are not completelyfamiliar with the fail-safe features of this devicemay render such features inoperable.
Since the instrument is small enough to beshipped by airmail or UPS, factory repair servicewill inevitably be the fastest and least expensivemethod of repair.
4.1 Troubleshooting

44Electrodes must be cleaned following each ionto-
phoresis procedure. 
1Remove remaining Pilogel disc material fromelectrodes.
2Use a cotton ball or swab with purified waterto thoroughly clean each electrode.
3If the electrode appears dirty after an extend-
ed idle period or will not clean with steps 1and 2, try using a small round piece of lightduty cleaning pad (such as 3M ScotchBrightª#7445) to buff the electrode surface. 
CAUTION!
Never use harsh abrasives such as steel wool,
sandpaper or emery cloth to clean electrodes.
Never scrape electrodes with metal tools. 
SECTION 4TROUBLESHOOTING AND MAINTENANCE4.2 Cleaning the ElectrodesNOTE:
When needed, the instrument case and electrodecable can be cleaned using a damp cloth soaked in a10% household bleach or mild soap solution. Avoidexcessive moisture to the instrument.

45SECTION 4TROUBLESHOOTING AND MAINTENANCE4.3 Replacing Inducer BatteriesThe battery compartment for the Webster SweatInducer is on the bottom of the unit. To accessand replace the batteries:
1Slide the battery access panel out andaway from the case.
2Remove the foam spacer from the end ofthe batteries.
3Carefully remove each battery from itsconnectors. Dispose of batteries properly,
(see below).
4Insert two new 9 volt batteries (typeEDA/ANSI 1604A). Be sure the batteriesare correctly aligned and seated in theconnectors.
5Replace the foam spacer at the end ofthe batteries.
6Replace the battery compartment lid.
BATTERY CARE AND DISPOSALDo not connect improperly, charge, or dispose ofin fire. Batteries can explode or leak. Do not carrybatteries loose in your pocket or elsewhere asburn injury may result.
Dispose of in accordance with applicable lawsand ordinances.
NOTE:
Always replace both batteries at the same time.
WARNING!

46

APPENDIX A 
SPECIFICATIONS
47

48

APPENDIX 
A 
Specifications 
MODEL 3700 WEBSTER SWEAT INDUCER 
Power Supply 2 x 9 V alkaline batteries, EDA/ANSI 1604A. 
Iontophoresis Current 1.5 mA (automatic). 
Iontophoresis Time 5 minutes 25 seconds maximum (automatic), at operating 
current. 
Current Control (a) Current profile-controlled, 20 second rise time, 
5 second fall time. 
(b)Provides full current at resistance up to 20,000 
ohms. 
(c) Fail-safe limited by circuit design. 
Fault Indication Audible tone. 
Current Flow Indicator Green LED, series-connected with the electrodes. 
Low Battery Indicator Amber LED. 
Electrode Set Jacketed stainless steel, premium-quality instrumentation 
lead wires, polarized locking connector. 
Case High impact polystyrene. 
Dimensions W x H x D 9.3 cm x 4.5 cm x 15.5 cm (3.7 x 1.77 x 6.10 inches). 
Weight 434 grams (0.96 lbs). 

50

APPENDIX B 
SUPPLIES AND 
REPLACEMENT PARTS 

52

APPENDIX 
B 
Supplies and Replacement Parts 
UNIT DESCRIPTION CATALOG NO 
1 ea. Electrode Set (red, black)
320566 
1 ea. Red Electrode Attachment Strap RP-044
1 ea. Black Electrode Attachment Strap RP-045
1 ea. Sweat Dispenser RP-065
1 ea. Nippers RP-066
1 ea. Supply Kit (materials for 6 sweat tests) SS-032
Containing:
12 ea. Pilogel Discs
6 ea. Macroduct Sweat Collectors
6 ea. Small Sealable Containers
1 ea. Macroduct Strap, Small (14 cm) SS-128
1 ea. Macroduct Strap, Medium (18 cm) SS-129
1 ea. Macroduct Strap, Large (25 cm) SS-130
1 ea. Macroduct Strap, Extra Large (39 cm) SS-131
1 set Macroduct Strap Set, 1 ea (Small, Medium, Large, Extra Large) SS-132
1 ea. Macroduct Sweat Collector SS-142

54

APPENDIX C 
A PERSPECTIVE ON 
THE SWEAT TEST 

56

57The "sweat test" provides laboratory confirmation of the clinicaldiagnosis of cystic fibrosis. It originated in the early 1950's followingthe discovery that children afflicted by the disease are prone toacute hyponatremia during hot weather. This occurs because of anabnormally high salt concentration in their eccrine sweat, rangingfrom three to five times higher than that of normal children. 
The prospect of obtaining a sweat specimen for analysis of its salt(or electrolyte) content is conceptually simple, but practical obsta-
cles to accomplishment of the diagnostic objective have madesweat testing one of the most controversial and criticized of all labo-
ratory procedures. This stems mainly from the fact that the test hastraditionally been associated with a large number of false results,
most of which fall into the equivocal (borderline) or positive range.
Complications connected to sweat testing resulted in somefatalities1(in the early days), and include numerous incidences ofskin burns to patients and minor allergic reactions.
Vociferous debate has raged among clinicians and researchers asto the efficacy of various sweat testing methods, often with littleapparent regard for the concerns of the beleaguered individual whomust actually conduct the test. As a result, the sweat test generallyranks as one of the least popular laboratory procedures that a med-
ical technologist must administer.
The sweat test is actually a composite of three separate, sequentialprocedures that must be accomplished without interventional error.
In order, they are (1)Sweat Stimulation,(2) Sweat Collection, and(3) Sweat Analysis. The 1959 pad absorption method of Gibson andCooke2introduced pilocarpine iontophoresis as a preferentialmethod of sweat stimulation, replacing the dangerous practice ofsweat stimulation by induced hyperpyrexia. The method is alsoknown as the "Quantitative Pilocarpine Iontophoresis Test," orQPIT.
Because the pad absorption method has withstood the test of time,
it is considered by many to be the reference method for sweat test-
ing. Unfortunately, the method is long and tedious, requiring manysteps where human error can intervene. Laboratorians in C.F. cen-
ters who specialize in this method of sweat testing develop the req-
uisite skills to maintain consistently accurate results; but in out-
lying clinics and hospitals where the test is requested only on anAPPENDIXC 
A Perspective on the Sweat Test

58APPENDIXCA Perspective on the Sweat Testoccasional basis, the chances of obtaining a false result haveproven to be unacceptably high.
The need for a simpler method spawned the development of alter-
native procedures during the late 60's and early 70's. Principallyamong these were the cup-collection systems which used electricalconductivity as the analytical procedure, and the direct-skin chlorideelectrode system. These methods were highly innovative, were pro-
cedurally simpler than the Gibson and Cooke method and werecommercially successful. They nevertheless failed in their objectiveto eliminate false diagnostic results. Wide adoption of the newsweat testing methods exacerbated the problem, evoking a storm ofcriticism in the professional literature with calls for a return to thepad absorption "reference" method.3,4In the United States, C.F.
referral centers operating under accreditation of the Cystic FibrosisFoundation were forbidden to use any sweat testing method otherthan the QPIT.
These early attempts to produce a simplified sweat testing systemfailed for two principal reasons: (1) error intrinsic to the method ofcollection and beyond the control of the operator, or (2) extremesusceptibility to variations in operator technique. Further progresswas stymied until these factors had been fully investigated and iden-
tified through research findings published in the late 70's.5,6In 1978, Wescor introduced the Model 3500 Webster SweatCollection System.7Its unique, heated collection cup* operated at atemperature slightly warmer than the skin. This prevented the con-
densate error that was intrinsic to all previous cup collection sys-
tems. It was the first "simplified" sweat collection method worthy ofcomparison to the Gibson and Cooke method, and it enjoyed con-
siderable commercial success.
The Webster system was a significant breakthrough in the effort todevelop a modern sweat collection system worthy of displacing thevenerated method of Gibson and Cooke. Despite the fact that theheated cup solved the most significant problem connected to cupcollection of sweat, it was nevertheless burdened by a problemcommon to all cup collection systems, i.e., the need to "harvest"
sweat accumulated under the cup during the collection period.
Wescor's commitment to resolve this problem eventually led 
*U.S. Patent No. 4,266,556

59to a significant breakthrough in the collection phase of the sweattestÐthe invention of the Macroduct¨* Sweat Collector.
Vested in Wescor's scientific and engineering staff is a combinationof many years experience in laboratory sweat testing and in thedevelopment of modern electronic laboratory instrumentation.
These professional talents were marshalled in support of the com-
pany's commitment to achieve objectives that it believed wereessential to advancing laboratory sweat testing from the era of the1950's to the present day:
1Eliminate all intrinsic sources of error concomitant to previouscollection methods.
2Ensure impeccable accuracy in the diagnostic result by reducinghuman error potential to the lowest possible level.
3Maximize patient safety and comfort.
4Maximize operator convenience within the strictures imposed byobjectives 1, 2, and 3.
During the development of the Macroduct system, Wescor'sresearch team conducted a comprehensive and detailed review ofevery aspect of the sweat test, with the object of simplifying the pro-
cedure to the greatest degree possible. Laboratory research andexperimentation led to a better understanding of the parametersgoverning stimulation by pilocarpine iontophoresis, and ultimately,
to the development of a fully automatic electronic sweat inducer thatrequires no judgmental decisions or adjustments by the operator. Areview of all currently available methods for sweat analysis wasmade in order to identify the procedure(s) most suitable for use withthe unique new method of collection.
With the introduction of the Model 3600 Macroduct Sweat CollectionSystem in 1983, all of the comprehensive objectives had been suc-
cessfully accomplished. Paramount among the system's severalunique and novel features was the innovative Macroduct disposablesweat collector.8, 9, 10, 11APPENDIXCA Perspective on the Sweat Test*U.S. Patent No. 4,542,751 U.K. Patent No. 2116850

60APPENDIXC 
A Perspective on the Sweat TestThe Macroduct sweat collector preserves absolute integrity in thecollected sweat specimen and gives the unprecedented advantageof visual quantitation of the volume of sweat collected at any timeduring the collection period. Other unique features of the systeminclude the unique Pilogel¨*12 pilocarpine reagent reservoirs thatprovide maximum protection from burns, eliminate the problem of'bridging," and are extremely simple and easy to use.
Macroduct sweat collection, combined with a modern, single-step,
micro-analytical procedure, provides a diagnostic result having thehighest confidence level in the history of laboratory sweat testing.
The Macroduct Sweat Collection System has been unequivocallyapproved by the U.S. Cystic Fibrosis Foundation for sweat stimula-
tion and collection.
In keeping with Wescor's commitment of excellence, still furtherimprovements have now been made in the Macroduct system. Thenew Model 3700 Webster Sweat Inducer has all of the fail-safe andconvenience features of its predecessor, the Model 3600, but doesnot require a separate charging unit or access to AC power forrecharging. It is powered by a pair of ordinary 9 volt alkaline batter-
ies that have sufficient capacity for up to a thousand separate ion-
tophoretic procedures.
Additional descriptive details and information covering each of theMacroduct Sweat Collection System components are foundthroughout this manual.
*U.S. Patent No. 4,383,529

61APPENDIXC1.Gibson, L.E., The sweat abnormality incystic fibrosis, Textbook of CysticFibrosis, (J.D. LLoyd-Still, ed., JohnWright, pub.) , PSG Inc., Littleton, Mass.,
3-7, 1983.2Gibson, L.E. and Cooke, R.E., A test forconcentration of electrolytes in sweat incystic fibrosis of the pancreas utilizingpilocarpine by iontophoresis, Pediatrics,
23, 545, 1959.3.Gibson, L.E., The decline of the sweattest, Clin. Pediatr., 12, 450, 1973.4.Rosenstein, B.J., Langbaum, T.S.,
Gordes, E., and Bruislow, S. W., Cysticfibrosis: problems encountered withsweat testing, JAMA, 240, 1987, 1978.5.Denning, C.R., Huang, N.N., Cuasay,
L.R., Shwachman, H., Tocci, P.,
Warwick, W.J., and Gibson, L.E.,
Cooperative study comparing threemethods of performing sweat tests todiagnose cystic fibrosis, Pediatrics, 66,752, 1980.6.Webster, H.L. and Lochlin, H., Cysticfibrosis screening by sweat analysis. Acritical review of techniques, Med. J.
Aust., 1, 923, 1977.7.Webster, H.L. and Barlow, W.K., Newapproach to cystic fibrosis diagnosis byuse of an improved sweat-induction/ col-
lection system and osmometry, Clin.
Chem., 27, 385, 1981.8.Webster, H.L., Laboratory diagnosis ofcystic fibrosis, CRC Critical Reviews inClinical Laboratory Sciences, CRCPress, Florida, 18, 313, 19839.Barlow, W.K. and Webster, H.L., A sim-
plified method of sweat collection fordiagnosis of cystic fibrosis, CysticFibrosis: Horizons, Proceedings of the9th International Cystic FibrosisCongress, Brighton, England, June 9th -
15th 1984 (D. Lawson, ed.), John Wiley& Sons, New York, 204, 1984.10.Carter, E.P., Barrett, A.D., Heeley, A.F.,
and Kuzemko, J.A., Improved sweat testmethod for the diagnosis of cystic fibro-
sis, Arch. Dis. Child., 59, 10, 919-922,
Oct. 1984.11.Sens, D.A., Simmons, M.A., and Spicer,
S.S., The analysis of human sweat pro-
teins by isoelectric focusing. I. SweatCollection utilizing the macroduct systemdemonstrates the presence of previouslyunrecognized sex-related proteins,
Pediatr. Res., 19, 8, 873-878, 1985.12.Webster, H.L., Improved pilocarpinereservoir for use in sweat testing, Clin.
Chem., 28, 2182, 1982.
ReferencesReferences

62

APPENDIX D 
PROCEDURE FOR 
HIGH SKIN RESISTANCE 

64

65APPENDIXDProcedure for High Skin ResistanceAlmost all of the electrical resistance in an iontophoretic circuit is provid-
ed by the two skin areas involved, and is due to the relatively dry deadcell layer of the epidermis, which varies in thickness according to bodyposition and also between individuals. When iontophoresis begins, theresistance is high, but rapidly reduces as the ducts begin to carry saltcontaining sweat to the skin surface. In the great majority of cases, thestandard pre-cleaning procedure of a brisk rub with alcohol and water toremove excess skin oils, a vigorous wash to remove as much dead cellmaterial as possible, and a final wetting of the involved areas just beforeapplying Pilogel will lower resistance to satisfactory levels. 
Special Procedure for Exceptional ResistanceIontophoretic shut down by the 3700 Sweat Inducer due to very highresistance is quite rare. However, the physiological literature containsmany references to high resistance in certain racial types where the skinis highly pigmented. In field sweat testing, such problems could arisewhere children of these racial types are involved. In such cases theunusually thick stratum corneum and dryness of the skin often conferselectrical resistance sufficient to shut down the circuit. In the past, withsimple battery and rheostat devices, the operator could increase theapplied voltage to dangerously high levels in order to overcome thisresistance and reach the desired current level, thus greatly increasing thepossibility of a serious burn. This is not possible with WescorÕs 3700Sweat Inducer.
Laboratories that frequently experience these high skin resistance char-
acteristics should use a specially modified Model 3700 Inducer delivering1.0 mA current. This allows the applied voltage to remain safely belowthe shut down level. The iontophoretic time on this modified SweatInducer is extended to 7.5 minutes to maintain the pilocarpine deliverycharacteristics for maximum sweat yield. Contact Wescor for furtherinformation and to have this specially modified loan instrument sentto perform the sweat test.

66

INDEX 
A cleaning 21, 32, 41, 44 
Abbreviated Instructions 33 faulty 42 
Alarm Tone(s) installing Pilogel discs in 23, 24 
disabling 11 negative (black) 22, 27, 53 
high circuit resistance 9, 41, pins 21 
high skin resistance 9 positive (red) 8, 22, 27, 28, 53 
low battery 9, 41 maintenance 11 
open circuit 11, 26 strap(s) 15, 25, 41, 53 
lead wires 11, 21, 26, 46 
Evaporation Error 37 
B 
Batteries 
disposing of 45 H 
low (weak) 9, 10, 26 High Skin Resistance 8, 63 
indicator 10 Hyponatremia 56 
replacing 41, 42 45 
I 
C Iontophoresis 8, 9, 12-27 
Circuit Resistance 9, 26, 65 burns during 14, 15, 23, 24 
Chloride Analysis 37 current 8, 9, 25 
Control Switch(s) sequence description 8 
ON/OFF 
RUN 8, 27 
START 9 L 
STOP 8, 9 Lead Wires (see electrode lead wires) 
Condensate Error 17, 37 Low Batteries 9, 10, 42, 45 
Conductivity 
diagnostic sweat analysis by 17, 37, 
58-62 M 
Current Flow Indicator 8, 26, 46 Macroduct 
Customer Service 4 Sweat Collection System 8, 56-
Cystic Fibrosis 3, 56-60 60 
collector 16, 26, 27, 28, 32, 53, 
58, 59 
D straps 27, 28, 30, 53 
Diagnosing Cystic Fibrosis 4 replacement parts 53 
Dye (in sweat sample) 16, 37 supplies 53 
E O 
Electrode(s) Osmolality 
attachment 13 diagnostic sweat analysis by 37 
ÒbridgingÓ 13 
circuit 8, 26 
67

INDEX 
P 
Pilocarpine 
iontophoresis (see iontophoresis) 
nitrate 12
Pilogel Iontophoretic Discs 12, 14, 15,
23, 24, 25, 32, 41, 53, 63
R 
RUN Switch 8, 9, 10, 26, 42
S 
Sodium Analysis 37
Specifications
safe use 5
environmental 5
system 49
Spiral (microbore) Collection Tubing 16,
29, 30
cutting 31
STOP Switch 8, 9, 10, 11, 46
Sweat 
analysis 4, 31, 37, 56-60
chloride assay 16 transporting to analyzer
volume 16, 29
yield 17, 29
Sweat (continued) 
collection 4, 16, 17, 27-29
collector 6, 7, 16, 17
dispenser 6, 7, 30, 53
electrolytes in 56
evaporation 17
induction 4, 12, 13
salt concentration in 56, 63
stimulation 12, 13, 21-26
test 17, 37, 53, 56-60
Sweat-Chek Analyzer, 31, 37
System
components 6, 7 
T 
Tuberculin Syringe 30, 31
W 
Webster Sweat Inducer 6, 7, 8, 41, 46, 57,
63
electrode plug 21
electronics 45, 46
instructions for use 21-27, 63
repair 4, 43