Monitoring human health behaviour in one's living environment: A technological review

Medical Engineering and Physics

Volumn 36, Issue 2, 2014, Pages 147-168

  Lowe, Shane A ^a   ÓLaighin, Gearóid ^a  

^a NATIONAL UNIVERSITY OF IRELAND   (Ireland)

Author keywords

Accelerometer; Ambient; Assisted living; Behaviour; Functional health; Gyroscope; Inertial sensor; Monitor

Indexed keywords

ACCELEROMETER; AMBIENT; ASSISTED LIVING; BEHAVIOUR; FUNCTIONAL HEALTH; GYROSCOPE; INERTIAL SENSOR; MONITOR;

ACTIVITIES OF DAILY LIVING; ENVIRONMENT; HEALTH BEHAVIOR; HUMANS; MONITORING, AMBULATORY;

EID: 84895075146     PISSN: 13504533     EISSN: 18734030     Source Type: Journal    
DOI: 10.1016/j.medengphy.2013.11.010     Document Type: Review

References (117)

1. Landi F., Russo A., Liperoti R., Barillaro C., Danese P., Pahor M., et al. Impact of inappropriate drug use on physical performance among a frail elderly population living in the community. European Journal of Clinical Pharmacology 2007, 63(8):791-799.
2. Pedersen B.K., Saltin B. Evidence for prescribing exercise as therapy in chronic disease. Scandinavian Journal of Medicine & Science in Sports 2006, 16(1):3-63.
3. Shah R.C., Buchman A.S., Leurgans S., Boyle P.A., Bennett D.A. Association of total daily physical activity with disability in community-dwelling older persons: a prospective cohort study. BMC Geriatrics 2012, 12(1):63.
4. Garatachea N., Molinero O., Martinez-Garcia R., Jimenez-Jimenez R., Gonzalez-Gallego J., Marquez S. Feelings of well being in elderly people: relationship to physical activity and physical function. Archives of Gerontology and Geriatrics 2009, 48(3):306-312.
5. Stephens T. Physical activity and mental health in the United States and Canada: evidence from four population surveys. Preventive Medicine 1988, 17(1):35-47.
6. Warburton D.E.R., Nicol C.W., Bredin S.S.D. Health benefits of physical activity: the evidence. CMAJ: Canadian Medical Association Journal 2006, 174(6):801-809.
7. Costigan S.A., Barnett L., Plotnikoff R.C., Lubans D.R. The health indicators associated with screen-based sedentary behavior among adolescent girls: a systematic review. The Journal of Adolescent Health: Official Publication of the Society for Adolescent Medicine 2013, 52(4):382-392.
8. Chomistek A.K., Manson J.E., Stefanick M.L., Lu B., Sands-Lincoln M., Going S.B., et al. Relationship of sedentary behavior and physical activity to incident cardiovascular disease: results from the women's health initiative. Journal of the American College of Cardiology 2013, 61(23):2346-2354.
9. Santos R., Mota J., Okely A. The independent associations of sedentary behaviour and physical activity on cardiorespiratory fitness. British Journal of Sports Medicine 2013, [epub ahead].
10. Swan M. Emerging patient-driven health care models: an examination of health social networks, consumer personalized medicine and quantified self-tracking. International Journal of Environmental Research and Public Health 2009, 6(2):492-525.
11. Swan M. Sensor Mania! The Internet of things, wearable computing, objective metrics, and the quantified self 2.0. Journal of Sensor and Actuator Networks 2012, 1(3):217-253.
12. Bravata D. Using pedometers to increase physical activity and improve health. JAMA: The Journal of the American Medical Association 2007, 298(19):2296-2304.
13. Woodward M.I., Cunningham J.L. Skeletal accelerations measured during different exercises. Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 1993, 207(2):79-85.
14. 2 uptake in humans during running and jumping. Journal of Applied Physiology 1980, 49(5):881-887.
15. Mathie M.J., Coster A.C.F., Lovell N.H., Celler B.G. Accelerometry: providing an integrated, practical method for long-term, ambulatory monitoring of human movement. Physiological Measurement 2004, 25(2):R1-R20.
16. Chen K.Y., Bassett D.R. The technology of accelerometry-based activity monitors: current and future. Medicine & Science in Sports & Exercise 2005, 37(11):S490-S500.
17. Culhane K.M., Lyons G.M., Hilton D., Grace P.A., Lyons D. Long-term mobility monitoring of older adults using accelerometers in a clinical environment. Clinical Rehabilitation 2004, 18(3):335-343.
18. Mathie M.J., Coster aCF, Lovell N.H., Celler B.G. Detection of daily physical activities using a triaxial accelerometer. Medical & Biological Engineering & Computing 2003, 41(3):296-301.
19. Heinz E., Kunze K., Gruber M., Bannach D., Lukowicz P. Using wearable sensors for real-time recognition tasks in games of martial arts: an initial experiment. IEEE symposium on computational intelligence and games 2006, 98-102.
20. Preece S.J., Goulermas J.Y., Kenney L.P.J., Howard D., Meijer K., Crompton R. Activity identification using body-mounted sensors-a review of classification techniques. Physiological Measurement 2009, 30(4):R1-R33.
21. Patel C., McCluskey P. Modeling and simulation of the MEMS vibratory gyroscope. 13th IEEE intersociety conference on thermal and thermomechanical phenomena in electronic systems 2012, 928-933.
22. Tong K., Granat M.H. A practical gait analysis system using gyroscopes. Medical Engineering & Physics 1999, 21(2):87-94.
23. Coley B., Najafi B., Paraschiv-Ionescu A., Aminian K. Stair climbing detection during daily physical activity using a miniature gyroscope. Gait & Posture 2005, 22(4):287-294.
24. Woodman O. An introduction to inertial navigation. Tech Rep. 2007, 696. Computer Laboratory, University of Cambridge, UK.
25. Bahreyni B., Shafai C. A resonant micromachined magnetic field sensor. Sensors Journal, IEEE 2007, 7(9):1326-1334.
26. Eaton W., Smith J. Micromachined pressure sensors: review and recent developments. Smart Materials and Structures 1999, 6(5):530-539.
27. Ding D., Cooper R.A., Pasquina P.F., Fici-Pasquina L. Sensor technology for smart homes. Maturitas 2011, 69(2):131-136.
28. Rialle V., Duchene F., Noury N., Bajolle L., Demongeot J. Health "smart" home: information technology for patients at home. Telemedicine Journal and e-Health 2002, 8(4):395-409.
29. Stelios M.A., Nick A.D., Effie M.T., Dimitris K.M., Thomopoulos S.C.A. An indoor localization platform for ambient assisted living using UWB. Proceedings of the 6th international conference on advances in mobile computing and multimedia 2008, 178.
30. Helal S., Winkler B., Lee C., Kaddoura Y., Ran L., Giraldo C., et al. Enabling location-aware pervasive computing applications for the edlerly. Proceedings of the 1st IEEE international conference on pervasive computing and communications 2003, 531-536.
31. Kelly D., McLoone S., Logan B., Dishongh T. Single access point localisation for wearable wireless sensors. Annual international conference of the IEEE engineering in medicine and biology society EMBC 2008, 4443-4446.
32. Otsason V., Varshavsky A. Accurate GSM indoor localization. UbiComp 2005: Ubiquitous Computing 2005, 903.
33. Chittaro L., Nadalutti D. A mobile RFID-based system for supporting evacuation of buildings. Mobile Response Lecture Notes in Computer Science 2009, 22-31.
34. Pavel M., Hayes T. Unobtrusive assessment of mobility. 28th annual international conference of the IEEE engineering in medicine and biology society EMBC 2006.
35. Pfeifer T., Elias D. Commercial hybrid IR/RF local positioning system. Proceedings of Kommunikation in Verteilten Systemen (KiVS) 2003, 1-9.
36. Lim C.H., Wan Y., Ng B.P., See C.M. A real-time indoor WiFi localization system utilizing smart antennas. IEEE Transactions on Consumer Electronics 2007, 53(2):618-622.
37. Blasco R., Marco A., Casas R., Ibarz A. Indoor localization based on neural networks for non-dedicated ZigBee networks in AAL. Bio-Inspired Systems: Computational and Ambient Intelligence 2009, 1113-1120.
38. Chen Q., Lee D., Lee W. Rule-based WiFi localization methods. IEEE/IFIP international conference on embedded and ubiquitous computing, 2008 EUC'08 2008, 1:252-258.
39. Sottile F., Giannantonio R. Design, deployment and performance of a complete real-time zigbee localization system. 1st IFIP wireless days 2008, 1-5.
40. Ciurana M., Barcelo-Arroyo F., Cugno S. Tracking mobile targets indoors using WLAN and time of arrival. Computer Communications 2009, 32(13-14):1552-1558.
41. Harvey N., Zhou Z., Keller J.M., Rantz M., He Z. Automated estimation of elder activity levels from anonymized video data. Annual international conference of the IEEE engineering in medicine and biology society EMBC 2009, 7236-7239.
42. Krumm J., Abowd G., Seneviratne A., Strang T. At the flick of a switch: detecting and classifying unique electrical events on the residential power line. UbiComp 2007: Ubiquitous Computing 2007, 271-288.
43. Cooper D. Comparison of activity sensors and algorithms for rate responsive pacemakers using ambulatory monitoring. Proceedings of computers in cardiology 1993, 851-854.
44. Puyau M., Adolph A., Vohra F. Prediction of activity energy expenditure using accelerometers in children. Medicine & Science in Sports & Exercise 2004, 36(9):1514-1521.
45. Matthews C.E., Chen K.Y., Freedson P.S., Buchowski M.S., Beech B.M., Pate R.R., et al. Amount of time spent in sedentary behaviors in the United States, 2003-2004. American Journal of Epidemiology 2008, 167(7):875-881.
46. Freedson P.S., Melanson E., Sirard J. Calibration of the Computer Science and Applications, Inc. accelerometer. Medicine & Science in Sports & Exercise 1998, 30(5):777-781.
47. Schofield W. Predicting basal metabolic rate, new standards and review of previous work. Human Nutrition Clinical Nutrition 1985, 39(1):5-41.
48. Harris J., Benedict F. A biometric study of human basal metabolism. Proceedings of the National Academy of Sciences of the United States of America 1918, 4(12):370-373.
49. Lorenzo A.D., Tagliabue A. Measured and predicted resting metabolic rate in Italian males and females, aged 18 to 59y. European Journal of Clinical Nutrition 2001, 55(3):208-214.
50. Frankenfield D., Roth-Yousey L., Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. Journal of the American Dietetic Association 2005, 105(5):775-789.
51. Tudor-Locke C., Brashear M.M., Johnson W.D., Katzmarzyk P.T. Accelerometer profiles of physical activity and inactivity in normal weight, overweight, and obese U.S. men and women. The International Journal of Behavioral Nutrition and Physical Activity 2010, 7(1):60.
52. Granat M.H. Event-based analysis of free-living behaviour. Physiological Measurement 2012, 33(11):1785-1800.
53. Raffin E., Bonnet S., Giraux P. Concurrent validation of a magnetometer-based step counter in various walking surfaces. Gait & Posture 2012, 35(1):18-22.
54. Ladetto Q. On foot navigation: continuous step calibration using both complementary recursive prediction and adaptive Kalman filtering. Proceedings of the 13th international technical meeting of the Satellite Division of the Institute of Navigation 2000, 1735-1740.
55. Najafi B., Aminian K., Paraschiv-Ionescu A., Loew F., Büla C.J., Robert P. Ambulatory system for human motion analysis using a kinematic sensor: monitoring of daily physical activity in the elderly. IEEE Transactions on Biomedical Engineering 2003, 50(6):711-723.
56. Aminian K., Najafi B., Büla C., Leyvraz P.F., Robert P. Spatio-temporal parameters of gait measured by an ambulatory system using miniature gyroscopes. Journal of Biomechanics 2002, 35(5):689-699.
57. Teh K.C., Aziz A.R., Stadium N. Heart rate, oxygen uptake, and energy cost of ascending and descending the stairs. Medicine & Science in Sports & Exercise 2002, 34(4):695-699.
58. Le X.H.B., Di Mascolo M., Gouin A., Noury N. Health smart home for elders - a tool for automatic recognition of activities of daily living. 30th Annual international conference of the IEEE engineering in medicine and biology society EMBS 2008, 3316-3319.
59. Hanser F., Gruenerbl A., Rodegast C., Lukowicz P. Design and real life deployment of a pervasive monitoring system for dementia patients. 2nd international conference on pervasive computing technologies for healthcare 2008, 279-280.
60. Breyer M.K., Breyer-Kohansal R., Funk G.C., Dornhofer N., Spruit Ma, Wouters E.F.M., et al. Nordic walking improves daily physical activities in COPD: a randomised controlled trial. Respiratory Research 2010, 11(1):112.
61. Lord S.E., McPherson K., McNaughton H.K., Rochester L., Weatherall M. Community ambulation after stroke: how important and obtainable is it and what measures appear predictive?. Archives of Physical Medicine and Rehabilitation 2004, 85(2):234-239.
62. Shoval N., Auslander G., Cohen-Shalom K., Isaacson M., Landau R., Heinik J. What can we learn about the mobility of the elderly in the GPS era?. Journal of Transport Geography 2010, 18(5):603-612.
63. Créange A., Serre I., Levasseur M., Audry D., Nineb A., Boërio D., et al. Walking capacities in multiple sclerosis measured by global positioning system odometer. Multiple Sclerosis 2007, 13(2):220-223.
64. Le Faucheur A., Abraham P., Jaquinandi V., Bouyé P., Saumet J.L., Noury-Desvaux B. Measurement of walking distance and speed in patients with peripheral arterial disease: a novel method using a global positioning system. Circulation 2008, 117(7):897-904.
65. Fjortoft I., Kristofferson B., Sageie J. Children in schoolyards: tracking movement patterns and physical activity in schoolyards using global positioning system and heart rate monitoring. Landscape and Urban Planning 2009, 93(34):210-217.
66. Roy S.H., Cheng M.S., Chang Ss, Moore J., Luca G.D., Nawab S.H., et al. A combined sEMG and accelerometer system for monitoring functional activity in stroke. Rehabilitation 2009, 17(6):585-594.
67. Lyons G.M., Culhane K.M., Hilton D., Grace P.A., Lyons D. A description of an accelerometer-based mobility monitoring technique. Medical Engineering & Physics 2005, 27(6):497-504.
68. Aminian K., Robert P., Buchser E.E., Rutschmann B., Hayoz D., Depairon M. Physical activity monitoring based on accelerometry: validation and comparison with video observation. Medical & Biological Engineering & Computing 1999, 37(3):304-308.
69. Godfrey A., Bourke A., Olaighin G., van de Ven P., Nelson J. Activity classification using a single chest mounted tri-axial accelerometer. Medical Engineering & Physics 2011, 33(9):1127-1135.
70. Philipose M., Fishkin K. Inferring activities from interactions with objects. Pervasive Computing 2004, 3(4):50-57.
71. Franco G.C., Gallay F., Berenguer M., Mourrain C., Couturier P. Non-invasive monitoring of the activities of daily living of elderly people at home - a pilot study of the usage of domestic appliances. Journal of Telemedicine and Telecare 2008, 14(5):231-235.
72. Fleury A., Vacher M., Noury N. SVM-based multimodal classification of activities of daily living in Health Smart Homes: sensors, algorithms, and first experimental results. IEEE Transactions on Information Technology in Biomedicine 2010, 14(2):274-283.
73. Virone G. Assessing everyday life behavioral rhythms for the older generation. Pervasive and Mobile Computing 2009, 5(5):606-622.
74. Pärkkä J., Ermes M., Korpipää P., Mäntyjärvi J., Peltola J., Korhonen I. Activity classification using realistic data from wearable sensors. IEEE Transactions on Information Technology in Biomedicine 2006, 10(1):119-128.
75. Lester J., Choudhury T. A hybrid discriminative/generative approach for modeling human activities. Proceedings of the 19th international joint conference on artificial intelligence 2005, 7662-7772.
76. Mase K. Activity and location recognition using wearable sensors. IEEE Pervasive Computing 2002, 1(3):24-32.
77. Rocha A., Martins A., Freire J.C., Kamel Boulos M.N., Vicente M.E., Feld R., et al. Innovations in health care services: the CAALYX system. International Journal of Medical Informatics 2011, 1-14.
78. Buckland M., Frost B., Reeves A. Liverpool Telecare Pilot: telecare as an information tool. Informatics in Primary Care 2006, 14(3):191-196.
79. Harrington D.M., Welk G.J., Donnelly A.E. Validation of MET estimates and step measurement using the ActivPAL physical activity logger. Journal of Sports Sciences 2011, 29(6):627-633.
80. Davies G., Reilly J.J., McGowan A.J., Dall P.M., Granat M.H., Paton J.Y. Validity, practical utility, and reliability of the activPAL in preschool children. Medicine & Science in Sports & Exercise 2012, 44(4):761-768.
81. Godfrey A., Culhane K.M., Lyons G.M. Comparison of the performance of the activPAL Professional physical activity logger to a discrete accelerometer-based activity monitor. Medical Engineering & Physics 2007, 29(8):930-934.
82. Dahlgren G., Carlsson D., Moorhead A., Häger-Ross C., McDonough S.M. Test-retest reliability of step counts with the ActivPAL device in common daily activities. Gait & Posture 2010, 32(3):386-390.
83. Chastin S.F.M., Granat M.H. Methods for objective measure, quantification and analysis of sedentary behaviour and inactivity. Gait & Posture 2010, 31(1):82-86.
84. Dyer C.A.E., Harris N.D., Jenkin E., Langley-Johnson C., Lewis R., Taylor G.J., et al. Activity levels after pulmonary rehabilitation what really happens?. Physiotherapy 2012, [epub ahead].
85. Saremi K., Marehbian J., Yan X., Regnaux J.P., Elashoff R., Bussel B., et al. Reliability and validity of bilateral thigh and foot accelerometry measures of walking in healthy and hemiparetic subjects. Neurorehabilitation and Neural Repair 2006, 20(2):297-305.
86. Huddleston J., Alaiti A., Goldvasser D., Scarborough D., Freiberg A., Rubash H., et al. Ambulatory measurement of knee motion and physical activity: preliminary evaluation of a smart activity monitor. Journal of Neuroengineering and Rehabilitation 2006, 3(1):21.
87. Zhang K., Pi-Sunyer F.X., Boozer C.N. Improving energy expenditure estimation for physical activity. Medicine & Science in Sports & Exercise 2004, 36(5):883-889.
88. Crouter S.E., Horton M., Bassett D.R. Validity of actigraph child-specific equations during various physical activities. Medicine and Science in Sports and Exercise. 2013, [epub ahead].
89. Trost S.G., McCoy T.A., Vander Veur S.S., Mallya G., Duffy M.L., Foster G.D. Physical activity patterns of inner-city elementary schoolchildren. Medicine and Science in Sports and Exercise 2013, 45(3):470-474.
90. Barreira T.V., Brouillette R.M., Foil H.C., Keller J.N., Tudor-Locke C. Comparison of older adults' steps/day using NL-1000 pedometer and two GT3X+ accelerometer filters. Journal of Aging and Physical Activity 2012, [epub ahead].
91. Stiles V.H., Griew P.J., Rowlands A.V. Use of accelerometry to classify activity beneficial to bone in premenopausal women. Medicine and Science in Sports and Exercise 2013, [epub ahead].
92. Cristofaro P.D., Pietrobelli A. Total energy expenditure in morbidly obese subjects: a new device validation. Obesity Research 2005, 13:A175.
93. Shuger S.L., Barry V.W., Sui X., McClain A., Hand G.A., Wilcox S., et al. Electronic feedback in a diet and physical activity based lifestyle intervention for weight loss: a randomized controlled trial. The International Journal of Behavioral Nutrition and Physical Activity 2011, 8(1):41.
94. Van Remoortel H., Raste Y., Louvaris Z., Giavedoni S., Burtin C., Langer D., et al. Validity of six activity monitors in chronic obstructive pulmonary disease: a comparison with indirect calorimetry. PLoS ONE 2012, 7(6):e39198.
95. Venkata A., DeDios A. Are depressive symptoms related to physical inactivity in chronic obstructive pulmonary disease?. Journal of Cardiopulmonary Rehabilitation & Prevention 2012, 32(6):405-409.
96. Smith K.M., Lanningham-Foster L.M., Welk G.J., Campbell C.G. Validity of the sensewear armband to predict energy expenditure in pregnant women. Medicine & Science in Sports & Exercise 2012, 44(10):2001-2008.
97. Ulas T., Buyukhatipoglu H., Eren M.A., Dal M.S., Torun A., Aydogan T., et al. Evaluation of sleeping energy expenditure using the SenseWear Armband in patients with overt and subclinical hypothyroidism. Clinical and Investigative Medicine 2012, 35(3):126-131.
98. Pfeiffer K.A., McIver K.L., Dowda M., Almeida M.J.C.A., Pate R.R. Validation and calibration of the actical accelerometer in preschool children. Medicine and Science in Sports and Exercise 2006, 38(1):152-157.
99. Hooker S.P., Feeney A., Hutto B., Pfeiffer K.A., McIver K., Heil D.P., et al. Validation of the actical activity monitor in middle-aged and older adults. Journal of Physical Activity & Health 2011, 8(3):372-381.
100. Godfrey A., Conway R., Meagher D., ÓLaighin G. Direct measurement of human movement by accelerometry. Medical Engineering & Physics 2008, 30(10):1364-1386.
101. Yang C.C., Hsu Y.L. A review of accelerometry-based wearable motion detectors for physical activity monitoring. Sensors 2010, 10(8):7772-7788.
102. Lowe S., ÓLaighin G. The age of the virtual trainer. Procedia Engineering 2012, 34:242-247.
103. Kennedy R., Boreham C., Murphy M. Evaluating the effects of a low volume stairclimbing programme on measures of health-related fitness in sedentary office workers. Journal of Sports Science and Medicine 2007, 6:448-454.
104. Petro S.A., Dannecker K.L., Melanson E.L., Browning R.C. Accuracy of research and consumer physical activity monitors in estimating energy expenditure. Medicine & Science in Sports & Exercise 2011, 43(5):61-62.
105. Dannecker K., Petro S. Accuracy of fitbit activity monitor to predict energy expenditure with and without classification of activities. Medicine & Science in Sports & Exercise 2011, 43(5):62.
106. Lee J.M., Welk G.J. Validity of consumer based physical activity monitors under free living. Medicine & Science in Sports & Exercise 2011, 43(5):700.
107. Scanaill C.N., Carew S., Barralon P., Noury N., Lyons D., Lyons G.M. A review of approaches to mobility telemonitoring of the elderly in their living environment. Annals of Biomedical Engineering 2006, 34(4):547-563.
108. Chan L., Ciol M.A., Shumway-Cook A., Yorkston K.M., Dudgeon B.J., Asch S.M., et al. A longitudinal evaluation of persons with disabilities: does a longitudinal definition help define who receives necessary care?. Archives of Physical Medicine and Rehabilitation 2008, 89(6):1023-1030.
109. Taraldsen K., Chastin S.F.M., Riphagen I.I., Vereijken B., Helbostad J.L. Physical activity monitoring by use of accelerometer-based body-worn sensors in older adults: a systematic literature review of current knowledge and applications. Maturitas 2012, 71(1):13-19.
110. Chaaraoui A.A., Climent-Pérez P., Flórez-Revuelta F. A review on vision techniques applied to human behaviour analysis for ambient-assisted living. Expert Systems with Applications 2012, 39(12):10873-10888.
111. Cheung V.H.V.H., Gray L., Karunanithi M. Review of accelerometry for determining daily activity among elderly patients. Archives of Physical Medicine and Rehabilitation 2011, 92(6):998-1014.
112. Krenn P.J., Titze S., Oja P., Jones A., Ogilvie D. Use of global positioning systems to study physical activity and the environment: a systematic review. American Journal of Preventive Medicine 2011, 41(5):508-515.
113. Kleissen R., Buurke J., Harlaar J., Zilvold G. Electromyography in the biomechanical analysis of human movement and its clinical application. Gait & Posture 1998, 8(2):143-158.
114. Croteau K. A preliminary study on the impact of a pedometer-based intervention on daily steps. American Journal of Health Promotion 2004, 18(3):217-220.
115. Paschali A.A., Goodrick G.K., Kalantzi-Azizi A., Papadatou D., Balasubramanyam A. Accelerometer feedback to promote physical activity in adults with type 2 diabetes: a pilot study. Perceptual and Motor Skills 2005, 100(1):61-68.
116. Clemes S.A., Deans N.K. Presence and duration of reactivity to pedometers in adults. Medicine & Science in Sports & Exercise 2012, 44(6):1097-1101.
117. Bornstein D.B., Beets M.W., Byun W., Welk G., Bottai M., Dowda M., et al. Equating accelerometer estimates of moderate-to-vigorous physical activity: in search of the Rosetta Stone. Journal of Science and Medicine in Sport/Sports Medicine Australia 2011, 14(5):404-410.