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Pulse  Oximeter  Repair  and  Troubleshooting  

Description  #   Text  Box   Explanation  or  Comment  
1   Begin:  Pulse  Oximeter   Begin  diagnostic  process  on  a  work  order  for  pulse  oximeter.  Maintenance  is  generally  requested  on  a  pulse  oximeter  when  it  cannot  read  SpO2  or  heart  rate  levels.  
2   Does  the  pulse  oximeter  power  on?   The  displays  should  appear  on  working  pulse  oximeter  when  powered  on.    
3   Troubleshoot  power  supply  (separate  chart).  

If  no  power  reaches  the  machine,  there  may  be  problems  with  the  switch,  fuse,  or  wiring.  See  flowchart  for  Power  Supply  and  BTA  skills  on  Power  Supply.  
4   Does  the  pulse  oximeter  power  on  with  the  battery  only?  

Though  the  machine  can  still  be  used  even  if  the  battery  charging  circuit  is  faulty,  the  battery  should  be  checked  for  functionality.  
5   Test  battery  voltage.   Use  a  multimeter  to  determine  if  proper  voltage  is  reaching  the  pulse  oximeter.  See  flowchart  for  Batteries  and  BTA  skills  on  Power  Supply.  
6   Charge  battery  if  needed  by  plugging  into  wall.   The  battery  needs  fourteen  hours  to  recharge  completely.    
7   Does  the  battery  charge?   If  the  battery  does  not  hold  charge,  the  machine  may  still  be  used  when  plugged  in.  
8   Check  battery  charging  circuit.   Ensure  that  the  circuitry  that  charges  the  battery  is  intact.  
9   Change  battery  if  needed.   Check  the  battery’s  replacement  date  and  change  it  if  it  is  faulty  or  if  the  date  has  passed.  
10   Go  to  begin.   Restart  the  diagnostic  process  to  see  if  the  corrective  measures  have  repaired  the  machine.  11   Disconnect  probe.   Remove  probe  from  pulse  oximeter.  
12   Does  the  alarm  sound?   The  alarm  should  not  only  sound  when  heart  rate  or  SpO2  levels  reach  outside  the  acceptable  ranges  but  when  the  probe  connection  with  the  machine  is  lost.  13   Check  connection.   Ensure  that  there  is  nothing  blocking  the  probe  

receptacle.  Clear  any  debris  or  dirt  that  may  interfere  with  probe  connection.  
14   Check  internal  circuitry  and  speakers.   Ensure  internal  circuitry  and  speaker  connections  are  intact.  See  BTA  skills  for  Electrical  Simple.  15   Reconnect  probe.   Reinsert  probe  into  pulse  oximeter.  
16   Does  the  alarm  stop  sounding?   Ensure  that  the  probe  connection  alarm  stops  when  the  probe  is  reconnected.  
17   Check  probe  connector.  Replace  if  pins  are  damaged.   If  the  pins  on  the  probe  connector  are  damaged,  bent,  or  broken,  the  probe  should  be  replaced.  
18   If  probe  is  still  not  being  recognized,  replace  probe.   If  the  alarm  continues,  the  problem  may  be  with  the  probe  itself.  Replace  the  probe.  
19   Is  one  light  sensor  visible  in  the  probe?   There  should  be  one  red  light  being  visibly  emitted  from  inside  the  probe.  
20   Clean  probe  with  a  70%  isopropyl  alcohol  solution  or  a  mild  detergent.  

Probe  can  also  be  cleaned  with  warm  water,  liquid  soap,  mild  chlorine  bleach  solution,  or  a  hydrogen  peroxide  solution.  Do  not  use  acetone,  butyl  alcohol,  denatured  ethanol,  Freon,  trichloroethylene  or  any  petroleum-­‐based  solutions.  See  BTA  skills  on  Mechanical  Cleaning.  
21   Replace  probe  if  light  is  still  not  visible.   If  light  is  not  being  emitted,  the  photodetector  cannot  read  the  signals.  The  pulse  oximeter  cannot  calculate  the  SpO2  value  or  heart  rate.  
22   Place  probe  on  finger.  Ensure  ambient  light  cannot  enter  sensor.  

When  not  in  use,  the  probe  should  be  shielded  from  direct  light.  If  any  outside  light  enters  the  sensor,  it  can  drastically  affect  readings,  as  they  are  calculated  through  photodetection  sensors.    
23   Does  SpO2  rate  (and  heart  rate,  if  applicable)  appear  when  probe  is  placed  on  finger?  

The  rate(s)  should  appear  on  the  display  one  the  probe  is  placed  on  the  finger.  
24   Reposition  probe  on  finger.   The  probe  may  be  placed  incorrectly  on  the  finger.  Ensure  it  is  not  too  tight  or  loose  and  no  outside  light  is  entering  the  sensor.  

25   If  readings  still  do  not  appear,  check  internal  circuitry.   Ensure  internal  circuitry  is  intact  and  connections  are  strong.  See  BTA  skills  on  Electrical  Simple.  
26   If  readings  still  do  not  appear,  replace  probe.   Ensure  correct  probe  is  being  used.  Other  probes  may  not  connect  correctly.  
27   Hold  breath  for  10-­‐20  seconds.   This  is  to  manually  check  if  the  SpO2  readings  decrease  with  less  oxygen  supply.  
28   Do  SpO2  levels  decrease  to  under  95%  (or  at  least  by  2%)?   As  you  hold  your  breath  longer,  the  rate  should  decrease  a  few  percent  at  least.    29   Replace  probe.   Attempt  again  with  a  new  probe.  
30   If  applicable,  calculate  true  heart  rate  using  stopwatch/neck  artery  technique.  

If  applicable,  calculate  heart  rate  manually  using  a  stopwatch  and  counting  pulse  rate  of  neck  artery  (or  wrist).  
31   Do  heart  rate  values  match  to  within  1bpm?   Compare  manually  calculated  values  to  pulse  oximeter  display.  32   Replace  probe.   If  values  are  not  with  1bpm,  replace  probe.  
33   Pulse  oximeter  is  working  properly.   Return  the  machine  to  the  appropriate  clinical  personnel.  

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