TRAINING AT SOS MEDICAL

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HOLY SPIRIT UNIVERSITY OF KASLIK

ENGINEERING FACULTY

TRAINING REPORT

Prepared by :

Elie SABBAGH

Entreprise :SOS MEDICAL

Training duration : From 17/02/14 till Present -

Advisor : Sandy RIHANNA

Course: GBM480

USEK – Spring 2013-2014

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Table of contents

I. Introduction

a) General introduction ………………………………… 4

b)Environment and knowledge acquired ……………....4

c)Work performed and missions ………………………..5

II. A Descrition of the work performed

a) Objective of the training………………………………7

b) List of available machines……………………………..7

c) Functionality, Repair and maintenance………………9

III. Conclusion

IV. List of figures

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Acknowledgement

Engineering students at USEK are required to accomplish 240 hours of training with a

biomedical company in order to graduate. I was lucky enough to have the opportunity to do my

training in SOS medical to acquire the required experience,but even even luckier to have recieved a

fixed job position as a technical manager at SOS. As part of this experience I was able to apply all

the theories and concept, as well as skills taught throughout the various courses I attended to practice

within the work setting.

I am amazed each day by how much knowledge and experience this company provides to it trainees.

I am always surrounded by many professionals and specialists, trying to find the easiest technical

solutions for complex issues. They are showing me how the biomedical world function in the scope

of reality.

Within my line of work I've faced various challenges that helped me develop effective planning

strategies and perform the supervisor's role adequatel, all of which are necessary for the role of an

engineer.

As a beginner, thanks to SOS I can say that I became integrated in the market of home care

biomedical equipment and in the wide world of biotechnology, merging my theories acquired at

university with my practical skills gained at work.

I want to express my gratitude to Mr. Badri BOU DARGHAM and Mr. Elie MOUBARAK founders

and owners of SOS MEDICAL, for their cooperation, motivation and appreciation. They were

always surrounding me by their full support in helping me build my carrier as a biomedical engineer.

I. Introduction

a. General introduction about SOSMEDICAL

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SOS MEDICAL provides superior home health care services and medical equipment to a variety of

clients Lebanon. SOS provides the Lebanese citizens with a first line resource for home care services

and medical products. No other company in Lebanon offers more products and services under one

roof than SOS. Our multi-divisional approach of separating each division and staffing it with the

best, most knowledgeable staff available has enabled us to effectively and successfully offer the

most variety of both products and services.

In addition to the medical equipment provided and maintained by SOS, the company is mostly

specialized in oxygen generators and ventilation machines since SOS has access to all Respironics

and Philips spare parts, manuals and trainings provided by these two companies..

SOS MEDICAL

Date of Establishment 1/1/1960

Establisher Mr. Badri Bou Dargham & Mr. Elie Moubarak

President Manager Mr. Badri Bou Dargham

General Manager Mr. Elie Moubarak

Location Baabda/Hazmieh

Address Centre Gardenia 3, fourth floor

Phone Number 05-933937

Fax 05-933937

E-mail [email protected]

Web Site www.sosmedicalliban.com

Agents

Branches

Respironics

Philips

More than 40 Branches worldwide

b. Environment and knowledge acquired

Talking about the environment where I did my training, I can say that it was a motivating

place, where an engineering student can find all the tools needed to work as an engineer, from the

simplest to the most complex. Moreover, the permanent access to the internet was really so

important, it helped us stay in continuous contact with our agents in other branches of our company..

We had access to all the technical data, spare parts etc…

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Now talking about the company’s main duty, is to provide adequate medical homecare to

patients referred to us by the health care system. We are responsible about installing the needed

equipments at the customers house and give them general formation concerning the mechanics of

using the machines and providing good care.

Problems can occur with the mahines. It is usually our responsibility to find the reason behind these

errors. Most common errors occur due to 1) irresponsible use of the machine by the patient or care

provider or 2) electrical reasons associated with the quality of Lebanese electricity.

c. Work performed : missions and succinct schedule

I remember my first day at work, where Mr. Elie Moubarak started to introduce me to the

different types of machines. Starting from that moment on I began on creating links between theories

acquired at university and the real world of biomedical engineering.

For example, I was able to understand quickly how an oxygen generator generates oxygen

and create the internal circuitry and sensors of the machine within my mind. The ability to create

the internal mechanics of the machine was a result of a Biomedical instrumentation course that I

took.

After being introduced to all the medical equipments provided by SOS I started to learn how

to choose the right machine, the right mode, and the good parameters to use for every machine in

relation to the patient's situation. These techniques helped when I started installing the medical

equipments in patients homes by myself.

Weeks later, I started facing problems with some machines. It was a new challenge for me

that I took with very high confidence. As my experience grew larger, I was able to detect the reason

why a machine is malfunctioning as a result I was able to repair almost all kind of problems faced.

Need to note when spare parts are used to repair a machine, new parts must be ordered instead. As a

result an RWO form is filled.RWO form is a paper in which SOS claims the malfunctioning

machine to the provider and asks for new spare parts…

Here is an exemple of a RWO sent to Respironics concerning a defected oxygen generator: “everFlo

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Respironics International Dealer Repair Work Order Form (RWO)

(please complete form in English)

Dealer Information:

Dealer Name: SOS MEDICAL Phone Number: 05955937

Contact Person: Fax Number: 05955937

Date (dd/mm/yy): Email Address:

RI Customer Number: Outside Repair* (Y/N)

* ”Outside Repair” is defined as service being performed on a unit not originally purchased by the dealer making this claim.

Product Information (ask at time of initial call to your customer):

Name of Product: Everflo Hours of operation*: 8490

Model Number: OPI

Serial Number: 0047827 Complaint received date: 30/03/14

Complaint Description:

Unstable Flow

Error Code(s) Reported:

Description of Patient

Circuit Setup:

Unit Settings: (based on unit, list

operating parameters)

* Also note if the hours are “unobtainable” due to the unit not being able to be turned on.

Patient Information (ask at time of initial customer call to your customer):

Was unit on a patient at the time of the reported problem (yes/no/not known): NO

Was there any patient harm or injury reported (yes/no/not known): NO

Was the unit’s alarm sounding (yes/no/not known): NO

Reported Alarm Code:

Note: Every effort should be made to complete this properly and the “not known” option should not be selected frequently.

Service Information:

Complaint confirmed (yes/no): YES

If no, identify current unit status:

Corrective action taken (include components replaced):

REPLACEMENT OF VALVE

Indicate the testing performed using

applicable service manual and/or current

Field Communications:

SERVICE MANUAL WAS CHECKED FOR PROPER

TECHNICAL SERVICE.

Warranty (yes/no): YES

If warranty, date of sale to your customer*:

* Note: Proof of sale may be requested by Respironics to validate warranty claim.

Component(s) Used:

RI part number: 1038827 Description: EverFlo Solenoid Assy

RI part number: Description:

RI part number: Description:

Internal Respironics Information:

Warranty approved (yes/no): Outside service confirmed (y/n)

Notification number: Dealer account credited (y/n)

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Email or Fax ( +49 (0) 8152 9306 19) completed RWO form to your Respironics Customer Service Representative.

In this way we can make sure that our machines will always be maintained and we will always be

supplied with any spare part we might need.

II. A description of the work performed

a. Objective of the training

My aim was to learn the process of biomedical maintenance and the steps needed from the

diagnostic period to reach the test period through the use of corresponding stimulators, providing a

solution , and repairing the equipment .

I am going to cover as much as possible, and briefly ,the types of machines existing in the the

company, a general overview about the technical part, the continuous care and work on these

machines, the encountered technical problems while repairing each one of these machines, and the

proposed solutions .

b. List of available machines in SOS

Oxygen generators

CPAP

AutoCPAP

BIPAP

AutoBIPAP

BIPAP S/T

BIPAP Avaps

Feeding pump

Syringue pump

Portable respirators

Syringue pump

Polysomnography

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c. Functionality, Repair and maintenance of biomedical equipment

Due to the limited number of paper in this project I will be choosing one of the equipment on wish

my training was most focused on during this period.

EverFlo Oxygen concentrator Overview

The EverFlo Oxygen concentrator produces concentrated oxygen from room air for delivery to a

patient requiring low flow oxygen therapy. The oxygen from the air is concentrated using a

molecular sieve and pressure swing adsorption processs. Only trained and qualified personnel should

repair these products using authorized parts

1. Features

a) Compact design

Compact design looks less like a medical machine

EverFlo's ergonomic design takes up less space and doesn't draw as much attention.

b) Ultra quiet operation

Ultra quiet operation reduces noise complaints

The EverFlo Q has only a 40 decibel sound level, which significantly increases patient satisfaction.

A feature advantage that's attractive to both physicians and patients.

c) Lower power consumption

Lower power consumption makes EverFlo patient-friendly

The system uses less electricity and produces less heat.

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d) Recessed flow meter

Recessed flow meter reduces accidental breakage

Recessed flow meter reduces accidental breakage

2. Theory of operation

a) Pneumatic Operation

Figure A

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Refer to figure A while reading the following discussion.

The room air is drawn into the unit through the air inlet filter by the compressor. The

compressed air is routed to the sieve beds through an electronically controlled valve/solenoid

assembly. The valve/solenoid alternates the air flow to a pair of sieve beds that allows oxygen

oxygen production.

The valve/solenoid assembly also alternates the flow through the sieve beds to allow purging of the

Nitrogen molecules from the sieve beds.

At startup, the valve/solenoid is de-energized allowing compressed air to flow through both

sieve beds until the pressure sensor builds up to switching pressure. At switching pressure, a 12-volt

signal is received at the valve/solenoid closing off the input and allowing the compressed air to cycle

through one of the sieve beds. As the air is cycled through one of the sieve beds, the molecular sieve

material traps the nitrogen molecules from the air and allows the Oxygen enriched air to flow

through the sieve bed.

At 5 liters of flow approximately 1/3 of the oxygen enriched air enters the product tank and

the other 2/3 of the oxygen enriched air is passed through an orifice in the sieve bed to purge the

trapped nitrogen molecules from the sieve bed, allowing the sieve materiel to be ready for oxygen

production during the next cycle.

The concentrated oxygen is stored in the product tank. The product tank is continuously filled

with concentrated oxygen and the output from the product tank is regulated at 5.5 psig nominal. The

product tank pressure is continuously monitored using a pressure sensor. The stored Oxygen is

delivered to the patient through a pressure regulator, and externally adjustable flow meter and a

microbial filter.

b) Electrical Operation

The everFlo Concentrator is a medical device which produces concentrated oxygen from room

air for delivery to a patient. It uses a molecular sieve and a pressure swing adsorption process to

concentrate oxygen from air. The device consists of filters, a compressor, a sive canister module, a

set of valves, a microprocessor-based electronic controller PCA, a flow meter and a cooling fan – all

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contained within a plastic enclosure.

The Everflo Embedded software _ via the microprocessor contained on the PCA

controller_controls the sieve valves used to generate the oxygen, measures/monitors the pressure &

oxygen levels, drives the elapsed time counter (Hour meter), reports exception conditions to the user

via visual and audible indicators and provide diagnostic information to a host computer via an

RS232 communications interface.

Figure B

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controller Overview

All the electric functions of the everflo reside on the PCA controller. A block Diagram of the PCA

controller is provided in figure B

The PCA controller can be sub-divided into 2 major sections:

1. Power distribution and DC voltage generation

2. Monitoring/Control/User Interface

Power

The AC mains power, via the line cord, is brought onto the PCA and the switched AC is

distributed to the Compressor, the cooling fan and to the AC to DC conversion module. The DC

voltages that are generated are used to power the remaining circuitry.

MicroProcessor And Associated Circuitry

The remainder of the PCA controller electronics is centered around the MSP430F155

microprocessor. The microprocessor is the only processing element contained in the Everflo

contractor. In addition to the microprocessor, the remaining circuitry consists of sensors, LEDS, a

piezo Audible indicator, amplifiers/signal conditioners, communication buffers and discrete

components.

The embedded software, in conjunction with the microprocessor and its associated hardware,

is used to control the sieve valves, measure/monitor the pressure & and oxygen levels, control the

oxygen sensor, drive the Hour meter, reports exception conditions to the User via visual and audible

indicators and provide information to a Host Computer.

PCA DETAILED DESCRIPTION

Power distribution

The AC mains power, via the line cord is routed to the PCA using connector #1. Fuse

protection for the AC mains as well as the ON/OFF (mains) switch are resident on the PCA. When

this switch is

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OFF, all power is removed from the board. The only exception to this is some limited backup power

provided by a charged “super cap”. The purpose of this backup power is discussed later.

The switched AC power is (output side of ON/OFF switch ) is distributed to the compressor

via connector #2, to the AC cooling fan via connector #3 and to the power generation module

contained on the PCA.

The switched AC power is the input to the DC Power generation module. The module

contains a step-down transformer that feeds a full wave rectifier diode bridge (with filter capacitor)

to generate approximaly 22 VDC

Using 4 voltage regulators and the aforementioned 22 VDC as an input, this module generates

the following voltages:

+12 VDC ; used to power the 2 sieve valves, the hour meter, the 3 LEDS and the audible

indicator. It is also used to power the external RS232 communications interface board that is

required for communication with an external host.

+5 VDC ; used to power the pressure sensor and the pressure sensor monitoring circuitry. It is

also used to charge the backup “super cap”

+3 VDC; used to power the microprocessor, the O2 sensor monitoring circuitry and the RS232

buffers.

O2 heater voltage ; used to power the heater contained in the O2 sensor. It is a variable voltage

capable of delivering an output current of up to 1 AMP. A buck regulator is used to generate this

voltage. The value of the reulator output voltage is controlled by the DAC output to the

microprocessor. Varying the DAC output from 0 to 3V yields an O2 heater voltage in the

approximate range, 0.8 thru 3.2 VDC.

Back Up capacitor and Associated Circuitry

The PCA contains a 1 Farad super capacitor which is used to sound the Audible Indicator when

the AC mains power is absent AND the mains switch is in the ON position. The purpose is to alert

the User to the fact that there has been a loss of AC mains power (that is, an AC mains power failure

a plug removal, a blown fuse…).

The circuitry functions as follows:

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1. During normal operation, the capacitor is energized (charged) using the +5VDC. The capacitor

reaches full charge after approximately ½ hour of system on time.

2. The mains switch has a 2nd

set of contacts that are used to determine whether the switch is open

or closed. If the switch is closed (in the ON position) and the microprocessor is not functional (

no DC power), then the backup circuitry is such that it will turn on the audible indicator using

the super cap as its energy source.

The “super cap” is capable is sounding the audible indicator for a period of greater than 8

minutes, given that it is fully charged.

MSP430 Microprocessor

The MSP430 is more than just a microprocessor; in addition to a processing element, it contains

FLASH and SRAM memory and variety of peripherial modules. Following is a list of the modules

contained within the MSP340

16 Kbytes of code FLASH memory

512 Bytes of SRAM memory

256 Bytes of info FLASH memory

Greater than 20 digital I/O lines

12-bit ADC with 8 input channels

12 bit DAC with 2 output channels

Pressure sensor and associated circuitry

The pressure sensor contains a single input port featuring Wheatstone bridge construction

and utilizing piezoresistive technology. The bridge excitation is +5V and the output signal is a

differential voltage that is proportional to the applied pressure. Both the sensor and its conditioning

circuitry are located in the PCA Controller.

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The ouput of the sensor is feed into a differential amplifier with a single ended, buffered output.

This conditioning circuitry is also powered by +5V. The output of the amplifier is feed into an ADC

channel in the MSP430.

The pressure sensor is un-calibrated both in gain and voltage offset. Calibration is therefore required

and it is performed at ICT test. The calibration parameters are stored in the info FLASH resident in

the microprocessor and are used by the embedded software to interpret the ADC pressure readings

that are acquired and processed during normal operation.

4. Repair and maintenance

After learning and studying the important technical information,

I finally found myself qualified in the techniques stated above and was able to detect any problem

faced with this type of machine and be able to suggest more than one solution and then test the

suggested hypotheses and make the optimal and most accurate decision to solve the problem faced.

To be clear and able to explain all the problems faced with the Everflo

I created the following table showing the symptoms that can warn us about a problem the probable

cause of the symptom the verification/confirmation of the problem and finally the corrective action

wish will lead us to finally solving the problem

.

Figure C

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figure D : Compressor

figure E : Sieve Bed

figure F: Main PCA

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Figure G: Valve solenoid

figure H: Pressure sensor

regulator

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Figure I: Inlet filter

Figure J : Flow Meter

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figure K : Fan

III. Conclusion

Knowing that I did my first 240 hours of training at Hopital Notre Dame de Liban, I can say that

choosing SOS medical for my second training/job was a very good choice. Because after this

training, I have formed a deeper overview about the functioning, the technical problems, the

solutions, and all the accessories of the machines that can be found in home care medical

equipments . I have watched real professionals working together and recruiting their skills and their

experience in the field to find out solutions to any problem that might arise.

After this training, I gave myself a definition for a biomedical engineer. If I were to be asked: What

is a biomedical engineer I would say: A biomedical engineer is a doctor. A doctor whose sole job is

to perform holistic care of any medical equipment. He identifies the malfunctioning symptoms and

completes the diagnostic techniques to find the fastest, most economical, and the most reliable

technical solution for an inoperative biomedical equipment .Working as a trainee in SOS medical,

has defined the career path I am aiming towards. SOS medical is one of the main milestone in the

path towards creating my future career. The love and passion I hold within towards Biomedical

Engineering will help me master this major and hopefully build the career I have always aspired for.

Finally, when it comes to the field of biomedical engineering, one finds himself able to leave a mark

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in the world, though it might be as small as a mustard seed, but that can make an enormous different

in the life of others.

IV. Liste of figures

Figure A : Pneumatic Block diagram

Figure B : PCA Controller block diagram

Figure C : Everflo in repair position

Figure D : Compressor

Figure E : Sieve bed

Figure F : Main PCA

Figure G : Valve solenoid

Figure H : Pressure sensor regulator

Figure I : Inlet filter

Figure J : Flow meter

Figure K : Fan

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