CAN LOW COST FINGERTIP PULSE OXIMETERS BE USED TO MEASURE OXYGEN SATURATION AND HEART RATE DURING WALKING? Jonas LaPier 1 , Megan Chatellier * 2 . 1  Research Assistant, Physical Therapy Department, Eastern Washington University, Spokane, WA, USA. *2 Assistant Professor, Physical Therapy Department, Eastern Washington University, Spokane, WA, USA. Corresponding   Author:   Dr.    Megan   Chatellier,   Eastern   Washington   University   PT   Dept.,   310   N   Riverpoint   Blvd,   Box   T,   Spokane,   WA   99202, USA. Phone: (509) 828-1372, Fax: (509) 828-1389 E-Mail:  functionaloutcomespt@gmail.com ABSTRACT Background:   Measurement   of   oxygen   saturation   (SpO2)   during   activity   and   exercise   is   important   for   clinical   treatment   and   prognostic decision-making,   but   oximeter   error   can   be   problematic.   New   generation   fingertip   pulse   oximeters   are   readily   available   and   inexpensive;     therefore,   their   potential   clinical   applications   are   rapidly   expanding.      While   the   performance   of   new   generation   tabletop   and   handheld pulse oximeters has been evaluated, little information is available on the accuracy of fingertip pulse oximeters, especially during activity. Purpose:    The   objective   of   this   study   was   to   determine   if   new   generation   low   cost   fingertip   pulse   oximeters   provide   accurate   and consistent measurements of oxygen saturation (SpO2) and heart rate (HR) during walking. Materials   and   Methods:   Nine   different   fingertip   oximeter   models   were   evaluated   during   treadmill   walking   at   one   and   two   mph   in   healthy subjects   (n   =   32).   Oximeter   readings   from   both   hands   were   simultaneously   recorded   and   a   15   second   electrocardiogram   (ECG)   strip   was printed.   Paired   t-tests   were   used   to   determine   differences   in   SpO2   measurements   between   oximeter   pairs.      An   ANOVA   was   used   to determine differences in HR measurements among oximeter pairs and ECG. Error rates were also calculated. Results:   A   significant   difference   in   SpO2   values   was   identified   between   oximeter   pairs   for   two   models   when   subjects   walked   at   one   mph. Additionally,   a   significant   difference   in   HR   values   existed   between   oximeter   pairs   and   the   ECG   for   two   models   when   subjects   walked   at   one mph.      No   differences   were   found   in   SpO2   or   HR   measurements   when   subjects   walked   at   two   mph.   Oximeter   performance   was   better when   measuring   SpO2   than   HR.   Also,   in   this   study   pulse   oximeters   performed   better   when   subjects   walked   at   higher   versus   lower   exercise intensities. Conclusions:   The   results   of   this   study   suggest   that   accuracy   and   consistency   of   fingertip   oximeter   measurements   are   less   than   ideal   during treadmill walking.  Clinicians should use caution when interpreting HR values obtained with fingertip pulse oximeters during exercise. KEY WORDS: Pulse oximeter, oximetry, oxygen saturation, heart rate, exercise, exercise-induced desaturation. References 1 . Hillegass   E,   Fick   A,   Pawlik   A,   Crouch   R,   Perme   C,   Chandrashekar   R,   et   al.   Supplemental   oxygen   utilization   during   physical   therapy   interventions. Cardiopulm Phys Ther J 2014; 25(2):38-48. 2 . Jubran A. Pulse oximetry. Crit Care 2015;19(272):1-7. 3 . Nitzan M, Romem A, Koppel R. Pulse oximetry: fundamentals and technology update. Med Devices: Evidence Res 2014;7:231-239. 4 . Shah   N,   Ragaswamy   HB,   Govindugari   K,   Estanol   L.   Performance   of   three   new-generation   pulse   oximeters   during   motion   and   low   perfusion   in volunteer. J Clin Anesth 2012; 24(5):385-391. 5 . Wilson   J,   Cowan   HJ,   Lord   JA,   Zeuge   DJ,   Zygun   DA.   The   accuracy   of   pulse   oximetry   in   emergency   department   patients   with   severe   sepsis   and   septic shock: a retrospective cohort study. BMC Emerg Med 2010;10(9):1-6 . 6 . Yamaura    K,    Irita    K,    Kandabashi    T,    Tohyama    K,    Takahashi    S.    Evaluation    of    finger    and    forehead    pulse    oximeters    during    mild    hypothermic cardiopulmonary bypass. J Clin Monit Comput 2007;21(4):249-252. 7 . Peng    L,    Yan    C,    Lu    H,    Xia    Y.    Evaluation    of    analytic    and    motion-resistant    performance    of    the    Mindray    9006    pulse    oximeter.    Med    Sci    Monitor, 2007;13(8):19-27. 8 . Petersen   L,   Chen   TP,   Ansermino   JM,   Dumont   GA.   Design   and   evaluation   of   a   low-cost   smartphone   pulse   oximeter.   Sensors   (Basel)   2013;   13:16882- 16893. 9 . Herbert JL, Wilson IH. Pulse oximetry in low-resource settings. Breathe 2012;9(2):91-97. 1 0 . Welsh   J,   Carr   R.   Pulse   oximeters   to   self   monitor   oxygen   saturation   levels   as   part   of   a   personalized   asthma   action   plan   for   people   with   asthma. Cochrane Database Syst Rev 2015;11;Article ID CD011584. 1 1 . Andrianopoulos   V,   Franseen   FM,   Peeters   JP,      Ubacks   T,   Bukari   H,   Groenen,   et   al.   Exercise-induced   oxygen   desaturation   in   COPD   patients   without resting hypoxemia. Respir Phys Neurobiol 2014;190:40-46. 1 2 . Dogra   AC,   Gupta   U,   Sarkar   M,   Padam   A.   Exercise-induced   desaturation   in   patients   with   chronic   obstructive   pulmonary   disease   on   six-minute   walk   test. Lung India 2015; 32(4):320-325. 1 3 . Sala   V,   Petrucci   L,   Monteleone   S,   Dall’angelo   A,   Miracca   S,   Conte   T,   et   al.   Oxygen   saturation   and   heart   rate   monitoring   during   a   single   session   of   early rehabilitation after cardiac surgery. Europ J Phys Rehabil Med 2016;52:12-19. 1 4 . Waltz   X,   Romana   M,   Lalanne-Mistrith   ML,   Machado   RF,   Lamarre   Y,   Tarer   V,   et   al.   Hematologic   and   hemorheological   determinants   of   resting   and exercise-induced hemoglobin oxygen desaturation in children with sickle cell disease. Haematologica 2013;98(7):1039-1044. 1 5 . Fletcher   GF,   Ades   PA,   Klingfield   P,   Arena   R,   Balady   GJ,   Bittner   V,   et   al.   Exercise   standards   testing   and   training:   a   scientific   statement   from   the   American Heart Association. Circ 2013;128:873-934. 1 6 . Sachdeva S. Fitspatrick skin typing: applications to dermatology. Indian J Dermatol Venereol Leprol 2009;75:93-94. 1 7 . Chatellier    M,   Koster   B,   LaPier   J.      Pulse   oximetry   accuracy   during   treadmill   walking   –   the   challenge   of   measuring   oxygen   saturation   and   heart   rate.     Cardiopulm Phys Ther J 2016; 27(1):38 (abstract). 1 8 . Barker SJ, Shah NK. The effects of motion on the performance of pulse oximeters in volunteers. Anesthes 1997;86:202-108. 1 9 . Mengelkoch LJ, Martin D, Lawler J. A review of the principles of pulse oximetry and accuracy estimates during exercise. Phys Ther 1994;74:40-49. 2 0 . Fadel PJ. Reflex control of the circulation during exercise.  Scand J Med Sci Sports 2015;25(4):74-82. 2 1 . McGovern   JP,   Sasse   SA,   Stansbury   DW,   Causing   LA,   Light   RW.   Comparison   of   oxygen   saturation   by   pulse   oximetry   and   co-oximetry   during   exercise testing in patients with COPD. Chest 1996;109(5);1151-1155. 2 2 . Wijshoff   RW,   Mischi   M,   Veen   J,   vender   Lee   AM,   Aarts   RM.   Reducing   motion   artifact   in   photoplethysmograms   by   using   relative   sensor   motion: phantom study. J Biomed Optics 2012;17(11):1-15. 2 3 . Yan    Y,    Poon    CC,    Zhang    Y.    Reduction    of    motion    artifact    in    pulse    oximetry    by    smoothed    pseudo    Winger-Ville    distribution.    J    Neuroeng    Rehabil 2005;2(3):1-9. 2 4 . Martin   D,   Powers   S,   Cicale   M,   Collop   N,   Huang   D,   Criswell   D.   Validity   of   pulse   oximetry   during   exercise   in   elite   endurance   athletes.      J   Appl   Physiol 1992;72(2):455-458. 2 5 . Crisafulli A, Marongiu E, Ogoh S. Cardiovascular reflexes activity and their interaction during exercise.  BioMed Res Internat 2015;1-10.  2 6 . Macleod   DB,   Cortinez   LI,   Keifer   JC,   Cameron   D,   Wright   DR,   White   WD,   et   al.   The   desaturation   response   time   of   finger   pulse   oximeters   during   mild hypothermia. Anesth 2005;60:65-71. 2 7 . Kober   A,   Scheck   T,   Lieba   F,   Barker   A,   Vlach   W,   Schramm   W,   et   al.   The   influence   of   active   warming   on   signal   quality   of   pulse   oximetry   in   prehospital trauma care. Anesth Analg 2002;95:961-966. 2 8 . Bickler PE, Feiner JR, Severinghaus JW. Effects of skin pigmentation on pulse oximeter accuracy at low saturation. Anesth 2005;102:715-719. 2 9 . Feiner   RJ,   Severinghaus   WJ,   Bickler   PE.   Dark   skin   decreases   the   accuracy   of   pulse   oximeters   at   low   oxygen   saturation:   the   effects   of   oximeter   probe type and gender. Anesth Analg 2007;105:18-23.