Amulet: a wrist-worn mHealth platform (2011-2019)

This project is no longer active; this page is no longer updated.

Related website: []

Related projects: [Amanuensis], [Amulet], [Auracle], [SIMBA], [THaW], [TISH]

Related keywords: [iot], [mhealth], [patent], [privacy], [security], [sensors], [wearable]


Amulet close-up

In the Amulet project we developed a custom wrist-worn computing platform for mobile health (mHealth). Amulet is (1) a bracelet 'hub' for a body-area mHealth network; (2) a secure, multi-application mHealth platform; (3) always on - and always with you; (4) long lasting, with battery life of one week to one month; (5) discreet in communicating with its wearer; (6) able to support multiple apps that monitor stress, physical activity, and exercise in free-living conditions; (7) open-hardware and open-source. The original concept was described in a 2012 HotMobile paper [sorber:amulet], and two retrospective papers provide an overview of the whole project in 2019 [boateng:experience, kotz:amulet19]. The interactive tool to predict and tune energy consumption is described further in Travis Peters' dissertation [peters:thesis].

Our primary contribution was the development of the Amulet platform itself [hester:amulet], which includes an ultra-low-power hardware architecture and a companion software framework, including a highly efficient event-driven programming model, low-power operating system, and developer tools for profiling ultra-low-power applications at compile time. Our prototype had battery lifetime lasting weeks or even months, depending on the application, and our interactive resource-profiling tool predicted battery lifetime within 6-10% of the measured lifetime.

We also made several contributions to security, including innovative ways for memory protection on low-capability microcontrollers like the MSP430 used in Amulet [hardin:mpu, hardin:mobisys17]. This work appears again as a chapter in Hardin's thesis [hardin:thesis].

We further developed methods for cryptographic transfer of data from a low-power wearable (like Amulet) to a smartphone [harmon:thesis], and then from a smartphone into a secure cloud-based mHealth data storage system... which then allows the data contributor to control which data consumer(s) can retrieve certain slices of data from their mHealth streams [greene:sharehealth, greene:thesis].

We also developed several algorithms, applications, and studies related to the measurement of stress or the monitoring of physical activity [mishra:commodity, boateng:stepcount, boateng:geriactive, boateng:activityaware, boateng:stressaware, boateng:msthesis, boateng:stressaware-thesis]. In the culmination of this work, we showed that, using and off-the-shelf heart-rate sensor, we were able to detect stressful events with an F1-score of up to 0.87 in the lab and 0.66 in the field, on par with clinical-grade sensors [mishra:jcommodity]. For follow-on work, see the SIMBA project.

In collaboration with engineers, we assisted with the development of a custom, low-power, wrist-worn sensor for electrodermal activity (EDA), which can be helpful in measuring stress [pope:eda-bsn].

In collaboration with a physician and students at the medical school, we also demonstrated the potential for Amulet (and devices like it) to be used for remote- and home-monitoring of physical activity among older adults, with the aim of assisting them to retain physical capabilities sufficient for activities of daily living [batsis:rural, batsis:mowi, batsis:amulet-use, batsis:change, batsis:feasibility, batsis:usability, batsis:weight-loss, batsis:barriers, rauch:wtp, petersen:design].

We also assisted in the development of a customized handle for an exercise resistance band -- typified by those from brand Theraband -- to enable clinical and research teams to measure a participant's use of the exercise band. The handle measures force induced on the handle by the band, and algorithms extract the number of repetitions [seo:theraband, peterson:chase, batsis:development].

For more information about the Amulet project, and a broader description of its contributions and publications (not just those including David Kotz and his students), see the Amulet website.


Amulet is freely available for personal, educational, and research use, open-hardware and open-source.

Some Amulet technology is covered by two patents: [kotz:patent9936877, kotz:patent9595187].


Amulet involved many students, staff, and faculty, primarily at Dartmouth and Clemson University.

David Kotz and George Boateng, with Amulet Core researchers: John Batsis, George Boateng, Kelly Caine, Eric Chen, Kevin Freeman, Emily Greene, Bhargav Golla, Ryan Halter, Taylor Hardin, David Harmon, Josiah Hester, Hilary Johnson, Anna Knowles, David Kotz, Sarah Lord, Byron Lowens, Zachary Marois, Varun Mishra, Andrés Molina-Markham, Vivian Genaro Motti, Emma Oberstein, Travis Peters, Curtis Petersen, Ronald Peterson, Gunnar Pope, Patrick Proctor, Sougata Sen, Lillian Seo, Joseph Skinner, Jacob Sorber, Kevin Storer, Emily Wechsler, and Tianlong Yun. Collaborators: Christina Aquila, Rima Al-Nimr, Stephen Bartels, Hang Cai, Elizabeth Carpenter-Song, Matthew Clark, Summer Cook, Cory Cornelius, Kevin Curtis, Rachel Dokko, Karen Fortuna, Diane Gilbert-Diamond, Tyler Gooding, Ann Haedrich, Steven Hearndon, Stephanie Lewia, Francisco Lopez-Jimenez, Jasmine Mai, Todd Mackenzie, Shrirang Mare, Auden McClure, John Naslund, Dawna Pidgeon, Aarathi Prasad, Meredith Roderka, Sivan Rotenberg, Richard Rothstein, Ryan Scott, Diane Sette, Minho Shin, Emma Smithayer, Courtney Stevens, Aaron Weintraub, K.C. Wright, and Alexandra Zagaria.

Funding and acknowledgements

This research program is supported by the National Science Foundation (NSF) under award numbers CNS-1314281, CNS-1314342, CNS-1619970, and CNS-1619950, with preliminary work funded by the NSF under award number 0910842 and by the Department of Health and Human Services (SHARP program) under award number 90TR0003-01. Dr. Batsis’ research reported in his publications was supported in part by the National Institute On Aging of the National Institutes of Health under Award Number K23AG051681.

The views and conclusions contained on this site are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the sponsors. Any mention of specific companies or products does not imply any endorsement by the authors or by the sponsors.

The Amulet logo was designed by the students of the DALI lab at Dartmouth. We are grateful for their creativity and assistance!

Papers (tagged 'amulet')

This list includes only those including David Kotz as co-author or thesis advisor. For a complete list of Amulet papers, see the Amulet website.

[The list below is also available in BibTeX]

Papers are listed in reverse-chronological order. Follow updates with RSS.


[Kotz research]