The research that is out there seems to indicate that the "One" or the "Flex" may be my best bet. In addition to using it as an accelerometer, I also want to use is as an indicator of sleep quality. Can anyone speak to that?

Hi Carl - I usually use MTI acelerometers - which are clumsy and require expertise to reduce the data. I do feel that commercial instruments are the way to go - only thing to keep in mind is that a vast majority of the research on PA is domne with MTI accelerometers so making comparisions across would be difficult.  That siad - I still feel FitBit would potential provde you with better wear time compliance. I don't know if you are aware of this recent paper;

Med Sci Sports Exerc. 2013 Nov;45(11):2105-12. doi: 10.1249/MSS.0b013e318299d2eb.

A comparison of energy expenditure estimation of several physical activity monitors.

Dannecker KL1, Sazonova NA, Melanson EL, Sazonov ES, Browning RC.

Author information

Abstract

INTRODUCTION:

Accurately and precisely estimating free-living energy expenditure (EE) is important for monitoring energy balance and quantifying physical activity. Recently, single and multisensor devices have been developed that can classify physical activities, potentially resulting in improved estimates of EE.

PURPOSE:

This study aimed to determine the validity of EE estimation of a footwear-based physical activity monitor and to compare this validity against a variety of research and consumer physical activity monitors.

METHODS:

Nineteen healthy young adults (10 men, 9 women) completed a 4-h stay in a room calorimeter. Participants wore a footwear-based physical activity monitor as well as Actical, ActiGraph, IDEEA, DirectLife, and Fitbit devices. Each individual performed a series of postures/activities. We developed models to estimate EE from the footwear-based device, and we used the manufacturer's software to estimate EE for all other devices.

RESULTS:

Estimated EE using the shoe-based device was not significantly different than measured EE (mean ± SE; 476 ± 20 vs 478 ± 18 kcal, respectively) and had a root-mean-square error of 29.6 kcal (6.2%). The IDEEA and the DirectLlife estimates of EE were not significantly different than the measured EE, but the ActiGraph and the Fitbit devices significantly underestimated EE. Root-mean-square errors were 93.5 (19%), 62.1 kcal (14%), 88.2 kcal (18%), 136.6 kcal (27%), 130.1 kcal (26%), and 143.2 kcal (28%) for Actical, DirectLife, IDEEA, ActiGraph, and Fitbit, respectively.

CONCLUSIONS:

The shoe-based physical activity monitor provides a valid estimate of EE, whereas the other physical activity monitors tested have a wide range of validity when estimating EE. Our results also demonstrate that estimating EE based on classification of physical activities can be more accurate and precise than estimating EE based on total physical activity.

Hope this helps!

cheers

lou

Thanks Dr. Hardy!

You hit the nail right on the head! I have often used Acticals in the past, but the expense of the devices and the hassle of data reduction has me looking for alternatives! I will certainly go out and find that paper  too!

Best,

Carl

Fitbit works great, but it partly depends on what you want to measure and the individual. The fitbit flex is simple and works great as a bracelet but since it measures wrist movements, it may not be good for measuring steps in some individuals with autism who do a lot of hand flapping. The Fitbit ONE or ZIP may be better for this purpose but if you want to measure hand flapping the Fitbit FLEX may be great for that purpose.

Thanks Dr. Sobsey!

The wrist vs. hip placement is an important consideration. With that in mind, I'm definitely leaning toward "One." Measuring hand-flapping with a wrist-device gives me some other ideas though... Thanks!!!

Hi Carl,

You might also want to check out SenseWear devices. I have used actiwatch devices in the past (predominantly for sleep/rest-wake activity characterisation) but again they are worn on the wrist. SenseWear is worn on the upper arm, and provides additional measurements to a lot of the other devices, so I am about to give them a try!

Sarah

Thanks! I greatly appreciate any hints! I will definitely look that up!

We use the Respironics Spectrum Actiwatch in all of our sleep studies.  It gives us a multitude of data - light intake, wrist activity, and built-in algorithms that estimate sleep fragmentation, quality, etc.  The analysis is relatively easy and it gives you really nice actograms.  The equipment is pricey, but they are sturdy devices (we used them during a basic training study and the watches survived!), and the software is pretty straightforward.  I currently have 16 devices - how many participants were you planning on running?  I could ask Dr. Youngstedt if he would mind letting you borrow a few temporarily.  Or, you could always swing by and I could let you try one out to see how it works.

Alex

Awesome! Thanks Alex!!! I will consider that, but as Dr. Sobsey (above) suggests, hand flapping might be problematic with a wrist device. Any thoughts on that? Or were you saying that it accounts for wrist activity?

No problem!  Well, it depends.. you can manually go through the data and remove the "noise" of the hand-flapping.. for example, have them put the watch on, flap their hands, and then silence all of the activity at that level (you would notice a huge spike in the activity data).  It would be like removing eye blinking from EEG data.  I would imagine that a device on the wrist would be much more comfortable for youth with ASD to wear, compared to waist actigraphy (it's uncomfortable and annoying even for non-ASD participants).  Or, you could always analyze the hand-flapping separately, which might be really useful data in of itself.  

Alex, your idea to "analyze the hand-flapping separately, which might be really useful data in of itself" is a thought that I also had the other day!!! I am wondering how difficult it would be to compare data from an Actiwatch with data from a hip-placed device? I have a few papers in my files somewhere comparing different devices so that might be a start. Have you done this before?

My experience working with children in secondary school who are diagnosed between the mild to the extreme autism range guides my advice. Frankly Carl, it depends on level of autism regarding successful outcome using a fit bit. Also, the time spent in close interaction that mutual attention requires by the parent/carer/researcher to manage monitoring is a consideration when working with autistic youth. Lastly, as an observer of a normal healthy adult who wears their fit bit 'one' and studiously monitors activity and calorie count daily (for the last 18 months), I think that the fit bit one  http://www.fitbit.com/uk/product (which clips onto trousers waistband)  or fitbit 'flex' (worn on the wrist) would be well suited to the task. Your question is an interesting one, good luck with your project!

Thanks Marianna! I am leaning toward the Fit Bit One. And thanks for the vote of confidence!

Hi Carl, sorry for the delayed response - I never get notifications when questions are answered on this site.  I know Dr. Jim Burch has done waist and wrist actigraphy validation work.  They are in the process of publishing the work that they did a few years ago.  I believe Dr. Girardin Jean-Louis has published validation studies, but I believe they might be wrist actigraphy/polysomnography studies.  It's tedious, but I know it can be done.  I did some work on the Burch study where I converted hundreds of files, but it was quite a while ago.  It would depend on the software and exactly what measurements they took in terms of activity.  It's all time-dependent, though, so if you could monitor hand-flapping via a specific algorithm (or a button recording on the watch), then you could sync the data.

Alex: Awesome! We should meet and discuss this some time in the next couple of weeks! Perhaps a morning next week other than Monday?

I'm going to send you an email so we can set up a day/time to meet!