Welch Allyn MicroTymp Printer/Charger User manual

MicroTymp

®

3 Handle and

MicroTymp

®

Printer/Charger

Service manual

Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

thereof without written permission from Welch Allyn.

Welch Allyn assumes no responsibility for any injury to anyone, or for any illegal or improper use of the product, that may result from

failure to use this product in accordance with the instructions, precautions, warnings, or statement of intended use published in this

manual.

Welch Allyn and MicroTymp are registered trademarks of Welch Allyn.

XP is trademark of Microsoft.

Software in this product is copyrighted by Welch Allyn or its vendors. All rights are reserved. The software is protected by United

States of America copyright laws and international treaty provisions applicable worldwide. Under such laws, the licensee is entitled

to use the copy of the software incorporated with this instrument as intended in the operation of the product in which it is

embedded. The software may not be copied, decompiled, reverse-engineered, disassembled or otherwise reduced to

human-perceivable form. This is not a sale of the software or any copy of the software; all right, title and ownership of the software

remain with Welch Allyn or its vendors.

For information about any Welch Allyn product, call the nearest Welch Allyn representative:

406695

Material No. 718441 Ver. A

www.welchallyn.com

USA + 1 315 685 4560

800 535 6663

Australia + 61 2 9638 3000

Canada 800 561 8797 China + 86 216 327 9631

European Call Center + 35 3 46 906 7790 France + 33 1 55 69 58 49

Germany + 49 7477 92 71 86 Japan + 81 42 703 6084

Latin America + 1 305 669 9003 Netherlands + 31 202 061 360

Singapore + 65 6419 8100 South Africa + 27 11 777 7555

United Kingdom + 44 20 7365 6780 Sweden + 46 8 58 53 65 51

Welch Allyn, Inc.

4341 State Street Road

Skaneateles Falls, NY 13153 -0220 USA

Regulatory Affairs Representative

Welch Allyn, Limited

Navan Business Park

Dublin Road

Navan, County Meath, Republic of Ireland

REF

iii

Contents

1 - Introduction and technical overview .........................1

About this document ..............................................1

Intended use.....................................................1

About the device..................................................1

Supporting documents and definitions .................................2

Definitions.......................................................2

Technical overview ................................................3

Controls, indicators, and connectors ..................................5

Handle components ............................................5

Printer/Charger components .....................................6

Symbols ........................................................7

General warnings .................................................9

General cautions ..................................................9

General notes ...................................................10

2 - Testing and verification ..................................11

Tools ..........................................................11

Bench test and calibration check - Handle .............................13

Purpose of test...............................................13

Preparation for test ...........................................13

Bench test procedures.........................................14

Final Tester Setup ............................................17

Testing Performed by the ATE ......................................22

Bench test for the Printer/Charger ...................................23

Proper powering up of unit .....................................23

Proper operation of print head ...................................24

Agency tests....................................................26

Dielectric strength test.........................................26

Grounding continuity test.......................................27

Leakage current test ..........................................27

3 - Troubleshooting guide ...................................29

Handle.........................................................29

Printer/Charger ..................................................30

Noise troubleshooting procedure ....................................31

Leak troubleshooting procedure .....................................32

Error and service code tables with troubleshooting procedure .............33

Error codes..................................................33

Retrieving and clearing error codes ...............................33

Service codes................................................35

4 - Disassembly and reassembly..............................37

Handle.........................................................37

Disassembly Procedures .......................................37

iv Contents Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

Removal/replacement of the LCD and keypad board assemblies ........42

Removal/replacement of the power PCBA .........................43

Removal/replacement of the MCU PCBA ..........................44

Replacement of Lithium coin battery ..............................45

Proper placement of ESD shields in the back housing.................45

Printer/Charger ..................................................46

Removal/replacement of the top panel ............................46

Removal/replacement of the main PC board and print head assemblies. . . 47

Removal/replacement of the contact housing and IR flex assemblies.....48

Removal/replacement of the printer keyboard/LEDs assembly ..........49

Removal/replacement of the RFI filter .............................49

Removal/replacement of old main PC board and print head ............50

A - Repair parts ............................................51

B - Cleaning...............................................55

Clean the handle .................................................55

Clean the printer/charger ..........................................55

Clean the probe tips ..............................................55

C - Replacement parts and accessories ........................57

1

Introduction and technical overview

About this document

This document is written for technical professionals who are qualified to service medical

instruments. The intended technical environment is any location where service on such

devices is performed. This document describes how to test, calibrate, diagnose,

disassemble, and assemble the MicroTymp3 Handle and MicroTymp Printer/Charger.

Before attempting service on the tympanometer, you must read and understand this

document and all other information that accompanies the tympanometer and its

accessories.

Intended use

This device is an auditory impedance tester intended to detect possible otologic disorders

associated with the functioning of the middle ear.

About the device

Federal US law restricts sale of the device identified in this manual to, or on the order of, a

licensed physician.

Using this device’s 226-Hz and 1000-Hz tympanometry settings, you can quickly and

easily obtain objective results supporting diagnosis of otitis media with effusion and other

middle ear disorders. This information can result in more thorough diagnoses as well as

more effective monitoring, treatment, consultation, and referral.

The 226-Hz test data stored in the memory of the Handle may be printed using the

Printer/Charger. The Printer/Charger reads the information from the Handle and prints out

tympanograms and interpretation.

The switch to change the default frequency is located on the top of the power supply PC

board. The table on the next page gives the function choices of this switch pack.

Note

The Handle also provides the ability to test patients utilizing a 1000-Hz frequency

mode. This mode features a quick interpretation result that displays a Pass, Refer,

or Retest message on the LCD (see Chapter 4 of the DFU, part number 714694).

Results from the quick interpretation mode can be documented using the 1000-

Hz screening results card. Results from the 1000-Hz quick interpretation mode

will not print.

2 Introduction and technical overview Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

The Printer/Charger also charges the rechargeable battery in the Handle.

For more detailed operating instructions, see the DFU for the MicroTymp3 Handle, part

number 714694.

Supporting documents and definitions

• Manufacturing Test Specifications for MicroTymp 2.5, DIR number 60029314

• DID for MicroTymp 2.5, DIR number 60029426

• MicroTymp3 Directions for Use, DIR number 80015401

• MicroTymp Hardware Technical Specifications, DIR number 60030837

• How2 - MicroTymp 2.5 MPS, DIR number 70020334

Definitions

Switch State Function

Switch 1 off 1000 Hz

Switch 1 on 226 Hz

Switch 2 off Platform communication

Switch 2 on Printer communication

Switches 3 and 4 Not used

ATE Automated Test Equipment

cc Cubic centimeter, a unit of volume

daPa Decapascal, the unit of air pressure used for tympanometric

measurements, 1 daPa = 1.04 mm H

2

0

EEPROM Electrically Erasable Programmable Read-Only Memory

LUT Look Up Table

mbar Unit of atmospheric air pressure measurement

mmho Acoustic millimho, the unit of acoustic admittance

MCU PCA Micro controller Unit Printed Circuit Board Assembly

PS PCA Power Supply Printed Circuit Board Assembly

USB Universal Serial Bus

UUT Unit Under Test

Vea Volume of ear canal

WACP Welch Allyn Communications Protocol

Service manual Introduction and technical overview 3

Technical overview

The Handle hardware contains the necessary circuitry to perform, measure, and report

tympanograms. It is designed to be portable and rechargeable, and to interface with its

corresponding printer device.

In order to perform a tympanogram, the hardware must support a motor/pump assembly

that is capable of a positive and negative pressure in the ear canal. Simultaneously, a

speaker must drive a monotonic 226-Hz, 85 dB sound pressure into the ear. A

microphone amplifier and A/D converter are included to monitor this sound pressure. The

control of the system (tone and pressure), and display of the tympanogram are

implemented with two micro controllers. The hardware and software must provide a

closed-loop system that maintains the 85 dB sound pressure, regardless of the acoustical

admittance in the ear that changes with pressure.

In addition, the Handle shall be capable of performing fully the above function with a

1000-Hz, 83 dB tone.

In order to support the operator interface, the hardware supports an LCD and keypad with

three keys. In order to interface with the Printer/Charger, the Handle has an IR sensor

communication interface. The Handle is designed to start by the press of a button, or by

insertion into the printer/charger unit.

The Handle hardware system is broken down at the top level into three board-level

assemblies:

1) The MCU Board

2) The Power Supply Board

3) The LCD Board

There are other integral components such as the sensors, motor/pump assembly,

switches, USB port, and IR interface which play significant roles in the plotting of the

tympanogram, the powering up of the unit, and the communication of the unit with a

service computer, ATE testing station, or Printer/Charger.

The Power Supply Board can be broken down into these subsystems:

1. The keypad/power up logic is responsible to start the power supply and interrupt the

master MCU whenever a key is depressed. It also reports which key is depressed and

receives an input from the MCU to keep the system powered up.

2. The battery charger provides a constant current charge to the battery whenever the

Handle is in a printer base. When the battery voltage reaches 4.2 volts, the charger

shall cease charging the battery.

3. The battery detection reports a low battery warning to the micro controller.

4. The negative power supply is an inverting switched capacitor power supply used to

support the analog circuitry and the LCD display.

5. The pump motor control provides a selectable voltage to the motor in either forward

or reverse polarity.

6. The pump motor home detect determines whether the pump diaphragm is above or

below the home position.

7. The valve control provides a fixed voltage to the valve in either the open or closed

polarity.

4 Introduction and technical overview Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

The MCU Board can be broken down into these subsystems:

1. The master micro controller is directly responsible for the sound pressure control

loop, operator interface, IR communication, USB communication, and power control.

2. The slave micro controller is directly responsible for the motor control, valve control,

and pressure amplifier.

3. The IR communication is a bidirectional link between the Handle and Printer/Charger

base.

4. The USB port is a bidirectional link between the Handle and either the ATE or the

service computer.

5. The speaker drive provides a 226-Hz sine wave to the speaker. The amplitude is

adjusted by the master MCU to control the sound compliance loop. Digital calibration

is also provided for speaker gain and system cavity size differences. These same

processes also apply to the 1000-Hz function of the Handle.

6. The microphone sends its signal to the A/D converter before filtering. This is true for

both the 226-Hz and 1000-Hz signals.

7. The ADC digitizes the output of the microphone amplifier to be used by the master

MCU in the compliance control loop. Digital calibration of the microphone gain is also

performed.

8. The pressure amplifier scales the signal from the pressure transducer and provides it

to the slave MCU. Digital calibration for transducer gain and offset are provided.

Service manual Introduction and technical overview 5

Controls, indicators, and connectors

Handle components

TEST

-400 -200 0 200

2

0.5

0

1.0

1

GR

A

GR

C

PRESSURE - daPa

Ya - mmho

+200 Vea - cc

MicroTymp

®

3

Portable Tympanometric Instrument

0297

IEC TYPE 3

Skaneateles Falls, NY USA

US Pat #5,383,097

ANSI TYPE 4

Patent Pending

C

US

74227

23650

REF

ON CTS

ON

OFF

123

4

ON CTS

ON

OFF

123

4

72910

REF

+

-

Lithium

Ion

Liquid Crystal

Display (LCD)

Left memory button

Test button

Right memory button

Infrared data

transfer window

Tip

Probe

Tip

ejector

Battery

cover

Micro-USB port

NOTE: Reserved for future use

Lithium-ion

battery

Side view Front view

Bottom view

Interior view

Handle

switches

6 Introduction and technical overview Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

Printer/Charger components

Power Cord

Tip box

POWER

indicator

CHARGE

indicator

FEED button

PRINT button

Paper

slot

Paper access

cover

Charging well for

MicroTymp 2 or 3

Card holder

with 1000-Hz

screening

results cards

IEC power cord

receptacle

Printer/Charger

switches

To IEC power

cord receptacle

To power

receptacle

Service manual Introduction and technical overview 7

Symbols

Documentation symbols

Warning

(Warnings indicate conditions or practices

that could lead to illness, injury, or death.)

Caution

(Cautions indicate conditions or practices

that could damage the equipment or other

property)

Consult instructions for use Hot surface

Operation symbols

POWER indicator FEED button

CHARGE indicator PRINT button

TEST button RIGHT memory button

Gradient width adult LEFT memory button

Gradient width child Switch options ON/OFF symbol

TEST

R

GR

A

L

C

GR

Shipping, storing, and environment symbols

Temperature limits Relative humidity limit

This end up Recycle

Recycle the product separate from other

disposables. See www.welchallyn.com/

weee for collection point and additional

information.

Separate batteries from other disposables

for recycling.

-20ºC

+49ºC

95%

95 %

Power and connectivity symbols

Lithium-ion

8 Introduction and technical overview Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

Certification symbols

Meets essential requirements of European

Medical Device Directive 93/42/EEC

74227

Complies with applicable U.S. and

Canadian medical safety standards

Class I equipment, Type BF

(Handle)

European regulatory manager

Class I equipment, Type B

(Printer/Charger)

0297

Miscellaneous symbols

Reorder number Manufacturer

Serial number

REF

SN

Service manual Introduction and technical overview 9

General warnings

General cautions

WARNING Explosion risk. Do not use Handle or Printer/Charger near flammable

anesthetics.

WARNING Electric shock hazard. Do not attempt to disassemble the Printer/

Charger. Refer all servicing to Welch Allyn or a Welch Allyn authorized service

representative.

WARNING Electric shock hazard. Use the USB connector only to connect to

devices complying with IEC 60601-1 or other IEC standards as appropriate to the

device. The user is responsible for verifying that the system complies with the

requirements of the system standard IEC 60601-1-1 if additional devices are

connected to the Handle.

WARNING Improper handling or disposal of the battery can lead to heat

generation, smoke, bursting, or fire.

WARNING Do not disassemble, modify, or solder the battery.

WARNING Do not directly connect (short circuit) the positive (+) and negative (–)

battery terminals.

WARNING To avoid short circuits, keep the battery terminals away from metal

objects.

WARNING Do not dispose of the battery in fire.

WARNING Do not expose the battery to temperatures above 80°C (176°F).

WARNING Use only the specified charger to charge the battery.

Caution Charge only Handle #23640, Handle #23650, or AudioScope 3

(#23300) in the Printer/Charger.

Caution If the device has not been stored within the operating temperature

range, allow 24 hours minimum for it to return to operating temperature range

(15-35°C or 59-95°F) before using.

10 Introduction and technical overview Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

General notes

The Printer/Charger (#7117x) will charge and print data from the MicroTymp2 or

MicroTymp3 Handle. However, the original Printer/Charger (#7113x) will neither charge nor

print data from the MicroTymp3 Handle.

Please complete and return the warranty registration. It validates the warranty and allows

Welch Allyn to communicate calibration notices and software changes.

Caution Do not store either the Handle or Printer/Charger at temperatures

below -20°C (-4°F) or above +49°C (120°F). Continual exposure to extremely low

or high temperatures can permanently damage components.

Caution The battery must be removed if the Handle is to be stored or placed

anywhere other than in the powered Printer/Charger for more than one month.

Failure to do this can result in damage to the Handle.

Caution This instrument contains components which are static sensitive.

Before touching any internal Handle component, be sure that you have

discharged any static electricity by touching a grounded metal object.

Caution To prevent equipment damage, charge the Handle only with the

Printer/Charger (#7117x).

2

11

Testing and verification

Tools

• Pressure applicator source with range of -400 to +300 daPa with 1 daPa

resolution

• Variable voltage (0-10 VDC) output power supply with at least 500 mA capacity

• Test cavity set, part number T20015974. See picture below for sizes.

• Handle

• Printer/Charger

• Digital voltmeter 3 ½ digit

• Hemostat or crimping needle nose pliers

• Set screw key, size 0.035

• Nut driver size 5/32 inch or 4 mm, thin wall preferred

• Other nut driver sizes needed: 3/16 inch and 1/4 inch

• Small and medium size Philips screwdrivers

• ROHS (lead free) soldering iron and lead free solder

• Tweezers

• Stop watch for leak test

• Service computer (Windows XP

®

, or higher) with 'Sample Client,’ version June

25, 2009. This program will give control of the Handle during the bench test. For

Sample Client to work On-Host Version 1.0.0 or equivalent must be installed prior

to using the WACP Sample Application.

• USB cable (thin connector) for connection to service computer

• B&K sound level meter model 2250, with ½-inch microphone model 4192 and

2 cc coupler model 4946

1

• Barometric Pressure transducer, model 276 or equivalent (must measure

pressure in mmHg)

1

1. These pieces are ATE. They are needed when the calibration is updated but not for the bench test.

Pressure box (T-5657 or equivalent) Test cavity set (T20015974)

12 Testing and verification Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

B&K sound level meter model 2250 1/2-inch microphone model 4192 and

2 cc coupler model 4946

Off-the-shelf tools

Barometer

Service manual Testing and verification 13

Bench test and calibration check - Handle

Purpose of test

To test for and detect problems in the following portions of the Handle:

1. Leak and vent rate

2. Noise (226 and 1000 Hz) and sweep rate test

3. Compliance check

For the purpose of detecting and repairing problems before the unit is run on the ATE.

This will alleviate failures on the final ATE test. Therefore, these tests should be

performed before final testing on the ATE.

Refer to the “Troubleshooting guide” starting on page 29 for solutions to the problems

encountered during the bench and ATE tests.

Preparation for test

1. Open the sample client program on the service computer by navigating to the

'Sample Client' folder. Open it and click on the 'Sample App' folder. Double click on

the 'Sample Client' file. Program will open. See opening screen picture.

2. Connect the USB cable from Handle to service computer.

Note

Use only the functions of sample client as set forth in this manual.

Note

Any time a new battery is installed it is necessary to connect the MicroTymp

handle to the USB cable or insert it into the printer/charger for five seconds before

powering up the handle. (This enables the battery protection circuit).

Sample client location

14 Testing and verification Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

3. Select the choices as shown in the picture below: 1 for start, 1 for number of

connections, and 2 for USB.

4. An extensive menu should display on the service computer screen. Making sure that

the Handle is powered on, select the number of the 'Disable Power Timeout,'

selection number 20. This will enable the Handle to stay powered up throughout the

test.

Bench test procedures

Test1-Leakandventtests

1. With the main menu still showing on the service computer screen, select number 12,

FmTYMP Test. The FmTYMP Test screen will show. Select number 3, Send

command. Select number 14, Set Valve. Select number 1 to close valve. An audible

Note

Wait approximately five to ten seconds to allow the "Sample Client" program to

recognize the connection. (The unit will not remain powered-up if this interval is

skipped.)

Opening screen

Sample client menu

Service manual Testing and verification 15

click will be heard indicating the valve has been latched closed. Unit can now be

tested for leaks.

2. Connect pressure box to the probe tip of the Handle. Throw select switch on pressure

box to positive position and pressure/vent switch to pressure position.

3. Adjust box to 300 daPa, let it sit for about ten seconds, and then observe the leak

rate. It must be less than 10 daPa in five seconds.

4. Vent the unit by throwing the pressure/vent switch on the box to vent position (V).

5. Put select switch in negative position and pressure/vent switch to pressure position.

6. Rotate the knob on the pressure box counter-clockwise to add negative pressure to

the unit. (+400 will appear on the T5657 digital readout.) Wait ten seconds and then

observe leak rate. It must be less than 10 daPa in five seconds.

7. Readjust pressure to -400 daPa.

8. Open valve on Handle by selecting number 3, Send command. Select number 14,

Set Valve. Select number 2 to open valve. Pressure should drop to zero in two

seconds or less.

9. To re-enable the timeout circuit, simultaneously press/release all three buttons on

Handle. Unit will power down. Power up unit and confirm that unit powers down in

about fifteen seconds.

10. Disconnect the USB cable from Handle and service computer.

Test 2 - Noise and sweep rate tests

1. Press the RIGHT and LEFT memory buttons simultaneously to set the unit to 226 Hz.

2. Put a 0.2 cc cavity on the probe tip. Hold unit upright and take a reading.

3. There should be a straight line across the bottom. Ideally, there should be no pixels

above the base line. If there are pixels one row above that is acceptable. Any pixels

two rows or more above the base line constitutes a failure. See pictures at the end of

this section.

4. Take four tympanograms and make sure all readings are a pass.

5. In addition, note the sweep across the bottom of the screen during a tympanogram. It

should move at an even speed. Make sure there is no notable slowdown or sudden

start/stops.

6. Repeat steps 2 through 5 for the 2.0 cc cavity.

7. Press the RIGHT and LEFT memory buttons simultaneously to set the unit to 1000

Hz.

8. Perform cavity tests for 1000 Hz with the 0.2 and 2.0 cc cavities.

Note

The cavity test for 1000 Hz will show the correct volume but not a straight line

across the bottom of the LCD. The line may be slightly elevated but no higher

than 0.4 mmho. It is important that the correct volume is displayed. If the

displayed reading is higher than 0.4 mmho, refer to the “Troubleshooting guide”

starting on page 29 for solutions to the problem. A REFER message will also

appear on the LCD, and it does not indicate a problem or a failure of the unit.

16 Testing and verification Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

Test 3 - Button test for 226 Hz function only

1. Place a 0.5 cc cavity onto the probe tip. Make sure cavity fits properly. The rubber tip

from the cavity should not be pulling away from the white tip ejector. See picture

below.

2. Press the 'TEST' button on the Handle. The unit should take a reading as a flat line

across the bottom of the screen. Press the 'L' button to store the reading into the left

memory. Observe the 'LEFT STORE' message.

3. Press 'TEST' button again. Unit takes another reading. Press the 'R' button to store

the reading into the right memory. Observe the 'RIGHT STORE' message.

4. Press and hold 'L' button. Left clear message appears in approximately four seconds.

Press and hold the 'R' button. Right clear message appears in approximately four

seconds.

1000 Hz Typmanogram

Volume

of

tested

cavity

Good tympanogram (226 Hz) Unacceptable tympanogram (226 Hz)

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