Amulet: Design, Development and Evaluation of a Wearable Device for mHealth Applications

Today we presented an “Experience” paper at ACM MobiCom, summarizing the technology, the studies, and the challenges and lessons learned over seven years of research.


George Boateng, Vivian Genaro Motti, Varun Mishra, John A. Batsis, Josiah Hester, and David Kotz. Experience: Design, Development and Evaluation of a Wearable Device for mHealth Applications. In Proceedings of the International Conference on Mobile Computing and Networking (MobiCom), October 2019. DOI 10.1145/3300061.3345432.

Abstract: Wrist-worn devices hold great potential as a platform for mobile health (mHealth) applications because they comprise a familiar, convenient form factor and can embed sensors in proximity to the human body. Despite this potential, however, they are severely limited in battery life, storage, bandwidth, computing power, and screen size. In this paper, we describe the experience of the research and development team designing, implementing and evaluating Amulet? an open-hardware, open-software wrist-worn computing device? and its experience using Amulet to deploy mHealth apps in the field. In the past five years the team conducted 11 studies in the lab and in the field, involving 204 participants and collecting over 77,780 hours of sensor data. We describe the technical issues the team encountered and the lessons they learned, and conclude with a set of recommendations. We anticipate the experience described herein will be useful for the development of other research-oriented computing platforms. It should also be useful for researchers interested in developing and deploying mHealth applications, whether with the Amulet system or with other wearable platforms.

Use of Amulet in behavioral change for geriatric obesity management

John Batsis and the Amulet team just published a paper regarding Use of Amulet in behavioral change for geriatric obesity management.

Background: Obesity in older adults is a significant public health concern. Weight-loss interventions are known to improve physical function but risk the development of sarcopenia. Mobile health devices have the potential to augment existing interventions and, if designed accordingly, could improve one’s physical activity and strength in routine physical activity interventions. Methods and results: We present Amulet, a mobile health device that has the capability of engaging patients in physical activity. The purpose of this article is to discuss the development of applications that are tailored to older adults with obesity, with the intention to engage and improve their health. Conclusions: Using a team-science approach, Amulet has the potential, as an open-source mobile health device, to tailor activity interventions to older adults.

John A. Batsis, Alexandra B. Zagaria, Ryan J. Halter, George G. Boateng, Patrick Proctor, Stephen J. Bartels, and David Kotz. Use of Amulet in behavioral change for geriatric obesity management. Journal of Digital Health, 5, June 2019. DOI 10.1177/2055207619858564.

Secure sharing of mHealth data

Emily Greene, Patrick Proctor, and David Kotz recently published a paper titled Secure Sharing of mHealth Data Streams through Cryptographically-Enforced Access Control:

Abstract:  Owners of mobile-health apps and devices often want to share their mHealth data with others, such as physicians, therapists, coaches, and caregivers. For privacy reasons, however, they typically want to share a limited subset of their information with each recipient according to their preferences. In this paper, we introduce ShareHealth, a scalable, usable, and practical system that allows mHealth-data owners to specify access-control policies and to cryptographically enforce those policies so that only parties with the proper corresponding permissions are able to decrypt data. The design and prototype implementation of this system make three contributions: (1) they apply cryptographically-enforced access-control measures to stream-based (specifically mHealth) data, (2) they recognize the temporal nature of mHealth data streams and support revocation of access to part or all of a data stream, and (3) they depart from the vendor- and device-specific silos of mHealth data by implementing a secure end-to-end system that can be applied to data collected from a variety of mHealth apps and devices.

Journal of Smart Health, 12:49-65, April 2019. DOI 10.1016/j.smhl.2018.01.003.

Amulet: an open-source wrist-worn platform for mHealth research and education

David Kotz recently presented a paper titled Amulet: an open-source wrist-worn platform for mHealth research and education.

Abstract: The advent of mobile and wearable computing technology has opened up tremendous opportunities for health and wellness applications. It is increasingly possible for individuals to wear devices that can sense their physiology or health-related behaviors, collecting valuable data in support of diagnosis, treatment, public health, or other applications. From a researcher’s point of view, the commercial availability of these “mHealth” devices has made it feasible to conduct scientific studies of health conditions and to explore health-related interventions. It remains difficult, however, to conduct systems work or other experimental research involving the hardware, software, security, and networking aspects of mobile and wearable technology. In this paper we describe the Amulet platform, an open-hardware, open-software wrist-worn computing device designed specifically for mHealth applications. Our position is that the Amulet is an inexpensive platform for research and education, and we encourage the mHealth community to explore its potential.

In Workshop on Networked Healthcare Technology (NetHealth), pages 891-897, January 2019. IEEE Computer Society Press.

DOI 10.1109/COMSNETS.2019.8711407.

Technology for Behavioral Change in Rural Older Adults with Obesity

A new paper from the extended Amulet group.

John A. Batsis, John A. Naslund, Alexandra B. Zagaria, David Kotz, Rachel Dokko, Stephen J. Bartels & Elizabeth Carpenter-Song. Technology for Behavioral Change in Rural Older Adults with ObesityJournal of Nutrition in Gerontology and Geriatrics, April 2019.DOI: 10.1080/21551197.2019.1600097

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Amulet usability evaluation

John Batsis et al. recently published a paper in Gerontechnology titled Usability evaluation for the Amulet Wearable Device in rural older adults with obesity:

Mobile health (mHealth) interventions hold the promise of augmenting existing health promotion interventions. Older adults present unique challenges in advancing new models of health promotion using technology including sensory limitations and less experience with mHealth, underscoring the need for specialized usability testing. We use an open-source mHealth device as a case example for its integration in a newly designed health services intervention. We performed a convergent, parallel mixed-methods study including semi-structured interviews, focus groups, and questionnaires, using purposive sampling of 29 older adults, 4 community leaders, and 7 clinicians in a rural setting. We transcribed the data, developed codes informed by thematic analysis using inductive and deductive methods, and assessed the quantitative data using descriptive statistics. Our results suggest the importance of end-users in user-centered design of mHealth devices and that aesthetics are critically important. The prototype could potentially be feasibly integrated within health behavior interventions. Centralized dashboards were desired by all participants and ecological momentary assessment could be an important part of monitoring. Concerns of mHealth, including the prototype device, include the device’s accuracy, its intrusiveness in daily life and privacy. Formative evaluations are critically important prior to deploying large-scale interventions.

Gerontechnology 2018;17(3):151-159

PDF: 2018 Batsis et al Gerontechnology Amulet

Sensing stress with commodity sensors

The Amulet group has been developing sensors, apps, and algorithms for sensing stress, in the field.  In one of the first papers to come out of that effort, presented today in a UbiComp workshop, we explore the potential for detecting stress using a single commodity wearable sensor.

Varun Mishra, Gunnar Pope, Sarah Lord, Stephanie Lewia, Byron Lowens, Kelly Caine, Sougata Sen, Ryan Halter, and David Kotz. The Case for a Commodity Hardware Solution for Stress Detection. In Workshop on Mental Health: Sensing & Intervention, pages 1717-1728, October 2018. ACM. DOI 10.1145/3267305.3267538.

Abstract: Timely detection of an individual’s stress level has the potential to expedite and improve stress management, thereby reducing the risk of adverse health consequences that may arise due to unawareness or mismanagement of stress. Recent advances in wearable sensing have resulted in multiple approaches to detect and monitor stress with varying levels of accuracy. The most accurate methods, however, rely on clinical grade sensors strapped to the user. These sensors measure physiological signals of a person and are often bulky, custom-made, expensive, and/or in limited supply, hence limiting their large-scale adoption by researchers and the general public. In this paper, we explore the viability of commercially available off-the-shelf sensors for stress monitoring. The idea is to be able to use cheap, non-clinical sensors to capture physiological signals, and make inferences about the wearer’s stress level based on that data. In this paper, we describe a system involving a popular off-the-shelf heart-rate monitor, the Polar H7; we evaluated our system in a lab setting with three well-validated stress-inducing stimuli with 26 participants. Our analysis shows that using the off-the-shelf sensor alone, we were able to detect stressful events with an F1 score of 0.81, on par with clinical-grade sensors.


Assembly of New Amulet “Kite.d” Boards Moves Forward

This spring, with a stabilized design code-named “Kite.d”, the Amulet team specified a new board and case design for the latest Amulet revision. Team members Ron Peterson and Taylor Hardin delivered the designs to New Hampshire’s DataEd, and with their assistance facilitated the fabrication of 150 Amulet Kite.d main- and daughter-boards. DataEd facilitated basic electrical testing of the design before delivery, and now that we’ve received them, the team is busy assembling the latest round of Amulets for upcoming studies. Check out some on-site pictures below!

DSCN0791Parts being placed on 6 Amulet Kite.d boards

DSCN0802A technician tests assembled boards for electrical soundness

DSCN0801Amulet team member Taylor Hardin tests functional capabilities of a new unit