vyaire MicroLab Mk8 Service Manual Issue 1.6 Sept 2019

Contents MicroLab - System Overview ... 4 MicroLab Mk8 System ... 4 Bi-directional Transducer ... 5 MicroLab Mk8 Repair ... 6 Disassembling the MicroLab Mk8 for repairs... 6 Disassembling the display ... 6 Reassembling the MicroLab after repairs ... 6 Circuit Descriptions ... 7 Controller ... 7 Battery Charger ... 7 Power Supply... 7 Transducer Ports ... 7 Keys, RS232, RTC, EEPROM... 8 Printer ... 8 Display, Touchscreen ... 8 USB Driver ... 8 Memory, Sound... 9 Fault Analysis ...10 Specifications ...10 Customer contact information ...11 Circuit Diagrams ...12 Controller ...12 Battery Charger ...13 Power Supply...14 Transducer Ports ...15 Keys, RS232, RTC, EEPROM...16 Printer ...17 Display, Touchscreen ...18 USB Driver ...19 Memory, Sound...20

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Information in this document is subject to change without notice and does not represent a commitment on the part of Vyaire Medical GmbH. Only the parts supplied by Vyaire Medical GmbH should be used to complete the service operation described in this manual. If in any way you feel unsure about the successful completion of the service operation you should contact Vyaire Medical GmbH or its appointed agent in your country or region and arrange the despatch of the product to a Vyaire Medical GmbH Service Centre. At Vyaire we constantly strive to improve our products. This may result in minor changes to devices which affect the way service activities need to be conducted. If you find that the service instructions you have do not reflect the actions you need to take to service your device, it is likely that the device you have is of a slightly different design specification than covered by the service manual. In that case, please contact our Technical Services Department (See page 11) who will be happy to provide you with the details you need.

Copyright 2019 by Vyaire Medical GmbH All rights reserved MicroLab Mk8 is a trademark of Vyaire Medical GmbH. All other products are trademarks or registered trademarks of their respective owners.

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MicroLab - System Overview MicroLab MK8 System The Vyaire MicroLab is a data recording spirometer consisting of a microcomputer unit incorporating a high resolution colour touch screen, internal printer, USB and RS232 interfaces, transducer ports and all associated circuitry. Supplied with the microcomputer is a Bi-directional transducer, disposable mouthpieces, mains adapter, nose clip and USB printer cable. The MicroLab is powered by internal Nickel Metal Hydride cells or by the mains adapter supplied. When testing a subject, the Bi-directional transducer is plugged into the microcomputer unit. The Bidirectional transducer is used to measure the subjects expired flow and volume in accordance with the operating manual.

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Bi-directional Transducer The Vyaire digital volume transducer consists of an acrylic tube with a vane positioned between two swirl plates. The low inertia vane is attached to a stainless steel pivot that is free to rotate on two jewelled bearings mounted at the centre of the swirl plates. As air is passed through the transducer a vortex is created by the swirl plates that cause the vane to rotate in a direction dependant upon the direction of airflow. The number of rotations is proportional to the volume of air passed through the transducer and the frequency of rotation is proportional to the flow rate. The transducer housing consists of a main body that contains a pair of light emitting diodes (LED’s) and phototransistors. The transducer is fixed to the mouthpiece holder that pushes into the main body and is captured by an “O” ring seal. The LED’s produces infrared beams, which are interrupted by the vane twice per revolution. This interruption is sensed by the phototransistors. The output from the collector of each phototransistor will be a square wave with a phase difference between the two of + or - 90 degrees depending upon the direction of flow. The square waves are detected by a microprocessor that measures the period of each pulse and transmits that information to the main unit via a high-speed asynchronous serial link. There is no routine maintenance required for the transducer other than cleaning according to the instructions in the operating manual.

Digital Volume Transducer

Rotating Infrared Swirl vane emitter plate

Jewelled bearing

Infrared detector Volume proportional to the number of pulses

Volume = k X No. of pulses

Flow proportional to the pulse frequency

Flow = k / pulse period

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MicroLab Mk8 Repair Disassembling the MicroLab Mk8 for repairs 1. Disconnect the mains power supply. 2. Open the printer cover and remove the paper roll from the unit.

We recommend that you use a Pozidriv No. 1 screwdriver for the following instruction.

3. Place the MicroLab Mk8 face down on a soft surface to remove the six screws in the lower moulding. Put the screws to one side. 4. Turn the unit face up before easing the upper and lower mouldings apart. Remove the paper cover and side panels. 5. Taking all precautions against static damage, lift the MicroLab PCB, battery and printer assembly out of the bottom moulding and place on an antistatic work surface. 6. Reconnect the power supply to the MicroLab Mk8 charging socket. 7. The MicroLab is now ready for fault finding.

Disassembling the display 1. Disconnect the mains power supply. 2. Disconnect the battery. 3. Press the ON/OFF button for about a second to make sure that all capacitors are discharged. 4. Now you can slightly open the flat cable connector and remove the display.

Reassembling the MicroLab after repairs 1. Disconnect all mains power supplies. 2. Place the MicroLab PCB (and printer/battery if connected) into the MicroLab bottom moulding. 3. Insert the Left hand side panel into the bottom moulding. 4. Insert the Right hand side panel into the bottom moulding and onto the ML8 PCB connectors by lifting the right hand edge of the PCB slightly 5. Ensuring that the keys do not fall out, position the top moulding over the bottom moulding and ensure that they both mate correctly. 6. Lift the rear of the top moulding to insert the paper cover hinge pins. 7. Clip the paper cover shut.

We recommend that you use a Pozidriv No. 1 screwdriver for the following instruction.

8. Place the MicroLab Mk8 face down on a soft surface and replace the six screws in the lower moulding. 9. The MicroLab Mk8 is now ready for operation.

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Circuit Descriptions Controller U1 is a Sharp LH79520 32 bit microprocessor with 32k of cache ram, and no internal flash memory. The system clock is supplied by 14.7456MHz crystal (X1). U2 is a reset controller, which holds the reset line low on power up. J1 is the JTAG interface for programming the unit. JP1 is the jumper that must be in place for programming, and removed for normal use. U3 is a multiplexer used to direct the communications to the correct channel on UART1. The directions are printer, MM sensor 1, and MM sensor 2.

Battery Charger The power to the system is either supplied by the 8.4V NiMH battery or from an external 12V DC regulated power supply. If the external supply is connected, then TR6 & TR12 are switched off and the battery is not used. R8 ensures that the battery is trickle charged at all times. Inductors L1 and L2 are placed for EMC filtering and D14 protects the unit from reverse polarity power supply. U36 is the charging circuit for the NiMH battery. The typical charge current is about 500mA, which equates to about 375mA out of the 12V supply. Charging is disabled when the unit turns on with TR23. U37 is a 1Hz oscillator used to blink the LED when the battery is charging. If the battery is fully charged CHARGE- is high, and the LED is on – assuming the mains is plugged in. TR27 and TR28 disconnect the battery from the battery charger to reduce the standby current.

Power Supply U4 is a step-down switching regulator used to create the 3.3 and 1.8 volt rails. U6 is a step-down switching regulator used to create the 5V rail. U33 is the power on circuit. If the unit is off and the on/off button is pushed, the unit should turn on. Eiter the microcontroller can turn off the unit using MC_OFF+ or holding the on/off button down for about 10 seconds can also turn the unit off if necessary. U5 is used to hold the unit off if the supply voltage is too low (approximately 5.5V). R24 and R25 divide the unregulated battery voltage, which is applied to a spare A/D channel in the touch screen driver. The µController continuously examines the reading and gives a battery low or battery dead warning message. Only all components on the “POWER_ON” net are constantly powered when the device is switched off to reduce the standby current.

Transducer Ports 2 Sensor ports are available for the unit to plug their transducers into (eg. Turbine, SPO2). U30 is used to translate the levels from 3.3 to 5V. U34, and U35, are used to buffer the receive line to the level translator. This was found to be necessary for the SPO2. TR17 is used to switch the power on for MM Sensor 1. TR19 is used to switch the power on for MM Sensor 2.

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Keys, RS232, RTC, EEPROM Three buttons are available on the unit. KEY0 is the ON/OFF button. KEY1 is the HELP button KEY3 is the PAPER FEED button U8 is used to generate an interrupt to the microcontroller if either the on/off or help button is pushed. U9 converts the RS232 signal to a logic signal of 3.3V. The µController uses channel 0 of its inbuilt serial controller for RS232 communication. The µController communicates with the PC over an RS232 serial interface: Baud Rate: 115200 bits/s Data Bits: 8 bits Stop Bits: 1 bit Parity: None BAT2 is a lithium coin cell to give the RTC power for up to 10 years. U10 is the RTC and is clocked by a 32.768kHz crystal. D2 enables power to be drawn from the main 3.3V regulator when the unit is on. U25 is a 32Kbyte EEPROM. This is used to store general settings and calibration data.

Printer The printer driver circuit is controlled by a Hitachi H8/3687 microprocessor U11. It includes the head driver, the motor driver, and the paper detection. The microprocessor has a built in Flash, which needs to be programmed by the main microcontroller, in order for the printer driver to operate correctly. U12 is used to drive the correct signals to rotate the motor. U13 is used to translate the communication levels from 3.3 to 5V TR1 is to turn off the 5V supply to the printer, when not required. U7 is a linear regulator for the 7V printer head voltage. J6 is used for debugging the printer, and should never even be populated in production. J7 is the connector for the head. J12 is the connector for the motor. J14 is the connector for paper detection.

Display, Touchscreen The 3.5” TFT LCD display is driven directly by the main microcontroller. The display has a built in touch screen and LED backlight, all on the same connector (J8). U28 and U29 are used to invert 2 lines from the processor. U14 is the touch screen controller. U16 controls a constant current through the LED backlight of the display. U15 can adjust the current to which U16 has to control. U17 is a step-up switching regulator used to create the appropriate voltages for the display (AVDD approx 8V, VGH approx 15V, VGL approx –8V).

USB Driver The cypress SL811HST U20 is a host/slave USB controller, which can be used for communicating with a PC or an external printer. In host mode 5V power is supplied through TR13, and switched on with TR14. The chip is clocked by a 48MHz crystal X4. U26 and U27 are used to switch between host and slave. 8

Memory, Sound U23 is a 32Mbyte FLASH 28F256P30 used to store all program code, and the files/filing system. U24 is a 2Mbyte SRAM CY62167DV30 used to store all volatile memory, such as video memory, and program memory. The sound driver includes a low-pass filter, a digital potentiometer, and an amplifier. The low-pass filter R100 and C110 turn the PWM digital signal from the microcontroller into an analog voltage. The digital potentiometer U18 is used to adjust the volume. The amplifier U19 is used to drive the 16ohm speaker with the final signal.

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Fault Analysis The following analysis is only a guideline and should be carried out in a logical sequence. If the fault is still apparent after the following suggestions then the unit should be fault found using the circuit descriptions and circuit diagrams provided. When the unit is turned on there is no display present Ensure charger is turned on at the mains. FVC readings are low Remove turbine from transducer housing. Taking the turbine, move it slowly through the air and check that the vane is not sticking. The unit does not recognise that the transducer is connected Ensure that the Bi-directional transducer is correctly plugged into the MicroLab. Inspect the Bi-directional transducer cable and connector for damage. The unit does not record any blows Inspect Bi-directional transducer cable and connector for damage. Ensure that the Bi-directional transducer is correctly plugged into the MicroLab. Remove turbine from the Bi-directional transducer housing. Taking the turbine, move it slowly through the air and check that the vane is not sticking.

Specifications Spirometry Measurements, (Forced)

VC, FEV.75, FEV1, FEV3, FEV6, FVC, PEF, FEV.75/VC, FEV.75/FVC, FEV1/VC, FEV1/FVC (FER), FEV3/VC, FEV3/FVC, FEV.75/FEV6, FEV1/FEV6, FEF25 (MEF75), FEF50 (MEF50), FEF75 (MEF25), FEF25-75 (MMEF), FEF50/VC, FEF50/FVC, MMEF/FVC (FEF25-75/FVC), FIV1, FIVC, PIF, FIV1/FIVC (FIR), FIF25 (MIF75), FIF50 (MIF50), FIF75 (MIF25), R50 (FEF50/FIF50), MET25-75, FET, MVV (ind)

Measurements, (relaxed)

EVC, IVC, IC, VT (TV), Ti, Te, Ti/Ttot., VT/Ti (TV/Ti), IRV, ERV, FR

Test Per Subject

5 relaxed VC manoeuvres and 8 forced manoeuvres for each baseline and two post examinations

Predicted Values

Various - depends upon national preference (including NHANESIII)

Transducer

Vyaire Gold Standard Bi-directional Digital Volume

Resolution

10ml volume 0.03l/s flow

Accuracy

+/- 3% to ATS recommendations - Standardisation of Spirometry 1994 update for flows and volumes

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General Storage

2000 patients with tests including Flow/Volume loops and Volume/Time graphs

Printer Output Medical

For the latest listing of compatible Hewlett Packard printers

(External Printers)

visit Vyaire Website at: www.vyaire.com

Printer Output

13mm/s (avg)

(Internal Printer) Power Supply

Input: 100-240V AC 50-60Hz Output: 12V 2.5A

Battery Pack

Rechargeable NiMH 8.4V 1Ah

Dimensions

25.5cm x 12cm x 3.5cm Transducer 50 x 60 x 90mm

Weight

Excluding any transducers: 630g

Operating Temperature

The instrument will operate in a uniform environment of 0°C - 40°C, out of direct sunlight

Operating Humidity

30-90% non-condensing

Operating Pressure

650 to 1060 hPa

Storage Temperature

-20°C to +70°C

Storage humidity

10% to 90% RH

Storage Pressure

650 to 1060 hPa

Connectivity

RS232 serial and USB 2.0

Customer contact information International customers only Technical Support Enquiries: Telephone:

0049 931 4972 127

Email: [email protected]

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Circuit Diagrams

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Vyaire Medical GmbH Leibnizstrasse 7 97204 Hoechberg Germany +49 931 4972-0 tel +49 931 4972-423 fax

JDE no. 36-MAN1203 Drg no. 085-46 Issue 1.6 September 2019 © Vyaire 2019

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