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Browsing by Author "Rodrigues, David"

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  • Do smartphone applications and activity trackers increase physical activity in adults? Systematic review, meta-analysis and metaregression
    Publication . Laranjo, Liliana; Ding, Ding; Heleno, Bruno; Kocaballi, Baki; Quiroz, Juan C; Tong, Huong Ly; Chahwan, Bahia; Neves, Ana Luisa; Gabarron, Elia; Dao, Kim Phuong; Rodrigues, David; Neves, Gisela Costa; Antunes, Maria Da Luz; Coiera, Enrico; Bates, David W
    Objective: To determine the effectiveness of physical activity interventions involving mobile applications (apps) or trackers with automated and continuous self-monitoring and feedback. Design: Systematic review and meta-analysis. Data sources: PubMed and seven additional databases, from 2007 to 2020. Study selection: Randomised controlled trials in adults (18-65 years old) without chronic illness, testing a mobile app or an activity tracker, with any comparison, where the main outcome was a physical activity measure. Independent screening was conducted. Data extraction and synthesis: We conducted a random-effects meta-analysis and all effect sizes were transformed into a standardized difference in means (SDM). We conducted exploratory metaregression with continuous and discrete moderators identified as statistically significant in subgroup analyses. Main outcome measures: Physical activity: daily step counts, min/week of moderate-to-vigorous physical activity, weekly days exercised, min/week of total physical activity, metabolic equivalents. Results: Thirty-five studies met inclusion criteria and 28 were included in the meta-analysis (n=7454 participants, 28% women). The meta-analysis showed a small-to-moderate positive effect on physical activity measures (SDM 0.350, 95% CI 0.236 to 0.465, I2=69%, T 2=0.051) corresponding to 1850 steps per day (95% CI 1247 to 2457). Interventions including text-messaging and personalization features were significantly more effective in subgroup analyses and metaregression. Conclusion: Interventions using apps or trackers seem to be effective in promoting physical activity. Longer studies are needed to assess the impact of different intervention components on long-term engagement and effectiveness.
    2021-04Journal article Open access Show more
  • Flexible RFID tag for bottle labelling
    Publication . Rodrigues, David; Pinho, Pedro; Mendes, Carlos
    This paper describes the design, manufacturing and range measurement of an UHF (ultra high frequency) RFID (radio frequency identification) tag to apply on a glass bottle filled with water. To achieve this, a free-space matched RFID antenna is studied and modifications are made in order reduce its size drastically and to turn it functional when applied to a bottle with water. Later, range measurement tests are made on the fabricated tag.
    2022-03-11Conference object Open access Show more