Here at ActiGraph, we are a bit obsessed with data and data quality. With the recent launch of our new ActiGraph LEAP^TM device, we can now capture higher volumes of raw sensor data than ever before. When coupled with newer and better algorithms to process the data into measures of interest, data insights that have previously eluded us are now possible. 

ActiGraph LEAP has a robust sensor array including accelerometer, multiwavelength photoplethysmogram (PPG), barometer, gyroscope, skin temperature sensor, and microphone. When a client approaches us with their study design, our team works with them to understand what digital measure(s) they are interested in calculating, which will then determine which sensors on the ActiGraph LEAP will be enabled to capture data that is used to generate those specific measures.  For example, if a study team is interested in capturing the sleep measure of total sleep time (TST) and the vital sign measure of heart rate (HR), then the accelerometer and the PPG sensor would be enabled.  

Sounds straight forward, right? Although technology has advanced considerably in recent years, limitations such as battery life and memory capacity can dramatically impact the usability of a wearable device. To illustrate this point, let us go back to our example study. Perhaps this study team does not need to collect raw data continuously; rather they only need to collect data during sleep periods and 15 minutes of PPG data every hour is sufficient. These adjustments to the data collection parameters have a significant impact on the device battery consumption, which could mean the difference between charging the device every day or only once a week. Reducing the frequency of battery charging reduces the participant burden, which can have a positive impact on study adherence and data quality. This is why it is critical that ActiGraph LEAP was designed as a fit-for-purpose, digital health technology (DHT) wearable device. 

With this type of study design in mind, we are excited to introduce two features to support flexibility and usability in studies using ActiGraph LEAP devices, duty cycles and event-based data capture.

Duty Cycles 

The duty cycles feature allows users to program ActiGraph LEAP devices to capture data at the same time every day. For optimal flexibility and usability, study designers can indicate recording increments as short as 15 minutes throughout a 24-hour period. We can also define a distinct pattern for each enabled sensor. As shown below, we have programmed the PPG sensor to capture data for 30 minutes every hour. 

With this duty cycle setup, we can define any daily repeat pattern, enhancing usability and giving study teams the ultimate flexibility without having to sacrifice data quality nor burden participants. 

Event-Based Data Capture 

Another typical use case is to capture data whenever the participant performs a certain action, for example, running, sitting, sleeping, etc. 

In this scenario, the ActiGraph LEAP device can be programmed to capture PPG data for 3 hours when the participant presses the event marker button on the side of the wearable device. It will stop collecting data if the participant presses the button again within the 3-hour window. This feature allows us to support a stopwatch, timer, or a combined timer and stopwatch behavior. 

These features are all great, but are they truly fit-for-purpose? Upon further discussion with our customers, we found that we need to provide the ability to activate both duty cycles and event-based data capture in a given study. The use case was as follows: 

Capture heart rate 15 min every hour when awake. Capture heart rate continuously during sleep. Mark in bed/out of bed with device button. If the participant forgets to press the device button getting out of bed, stop data collection after 10 hours. 

This would allow advanced data capture in a study with a combination of participants working day and night shift. 

The ActiGraph LEAP multisensor wearable device features one of the most comprehensive collections of sensors in the industry, which increases both the amount of data study teams can collect and the possibility of unique insights into human behavior and wellbeing. While the potential of the ActiGraph LEAP is exciting, this potential cannot be realized without considering the usability at the study team, site, and participant level.

We strive to optimize usability from every angle and believe that the introduction of duty cycles and event-based data capture features will improve usability from multiple stakeholder perspectives. For the ActiGraph LEAP to be a truly fit-for-purpose sensor-based wearable device, our customers need this kind of flexibility. 

Do you have an upcoming clinical trial and you're considering integrating a DHT solution? Find out more about our Usability Evaluation Program that can help you make a data-driven decision about whether ActiGraph's DHT solution is fit-for-purpose for your specific study.