JMIR Publications

ABSTRACT

Background:

Growing interest in promoting child health requires minimally invasive biospecimen collection. Particularly during and since the COVID-19 pandemic, there has been increased interest in microsampling technology to democratize participation in research involving biospecimens, particularly for children. These advances mitigate barriers, such as scheduling, transportation, and psychosocial challenges. Tasso is a microsampling biomedical device that has gained popularity in research. It uses a vacuum-assisted capillary system that attaches to the upper arm and is considered minimally invasive as it requires no venipuncture or phlebotomist. Yet, important gaps remain in understanding Tasso performance, particularly among pediatric populations where its administration is limited.

Objective:

This research addresses a significant gap in biomedical device development by examining the effectiveness, safety and failure rate of the Tasso+ Class II medical device designed for sampling blood (puncture) among children. The Tasso+ was selected for a pediatric cohort research study given advertisement of methodological advantages over traditional phlebotomy. This original investigation characterizes the effectiveness of, and potential for Institutional Review Board (IRB)-designated adverse events, following the use of the Tasso+ Class II medical device within a pediatric population.

Methods:

Blood collection was essential to measure lead (Pb) exposures for children residing in a known polluted region. Parents/guardians consented and children assented to Tasso+ sampling on the upper arm. The Tasso+ device was administered in 2024 by trained researchers on n=2 pilot participants (ages 7-8 years), and subsequently n=13 study participants (ages 7-10 years). Sampling was terminated upon reports of persistent pain and scarring on children's arms. Follow-up was conducted at intervals after device application 2-11 weeks and 10-19 months. Data sources include data collection and lab records and survey-based follow-up with participating families. Analyses involved descriptive statistics drawn from data collection and lab records, as well as a follow-up survey administered to families. Content analysis of open-ended responses to the follow-up survey administered to families identified themes and their frequency of occurrence. Main measures include the device failure rate, effectiveness, and adverse outcomes at the arm puncture site.

Results:

The device failure rate was 26.7%, with only 66.7% and 20.0% of cases having the optimal (>450µL) or adequate (250-449µL) blood volume, respectively. At initial follow-up, 23.1% reported ongoing pain; none reported ongoing pain at extended follow-up. Scarring showed high initial incidence (61.5%) and persistence (75.0%). Children reported shame from the scar and impacts of pain on feelings towards physical touch (e.g., hug/embrace).

Conclusions:

These effectiveness barriers and adverse events highlight the need for documentation to inform future roll-out of novel devices, participatory research, longer-term follow-up, and potential gaps in transparency between manufacturers and researchers who employ biomedical devices.