Improvement of the Upper Detection Limit of Ionophore-Based H+-Selective Electrodes: Explanation and Elimination of Apparently Super-Nernstian Responses.

The response range of an ion-selective electrode (ISE) has been described by counterion interference at the lower and Donnan failure at the upper detection limit. This approach fails when the potentiometric response at the upper detection limit exhibits an apparently super-Nernstian response, as has been reported repeatedly for H+-selective electrodes. While also observed when samples contain other anions, super-Nernstian responses at low pH are a problem in particular for samples that contain phthalate, a common component of commercial pH calibration solutions. This work shows that coextraction of H+ and a sample anion into the sensing membrane alone does not explain these super-Nernstian responses, even when membrane-internal diffusion potentials are taken into account. Instead, these super-Nernstian responses are explained by the formation of complexes between that anion and at least two protonated ionophore molecules. As demonstrated by experiments and explained with quantitative phase boundary models, the apparently super-Nernstian responses at low pH can be eliminated by restricting the molecular ratio of ionophore and ionic sites. Notably, this conclusion results in recommendations for the optimization of sensing membranes that, in some instances, will conflict with previously reported recommendations from the ionic site theory for the optimization of the lower detection limit. This mechanistic insight is key to maximizing the response range of these ionophore-based ISEs.

Exploring User Perspectives on Brief Reflective Questioning Activities for Stress Management: Mixed Methods Study.

BACKGROUND: Current online interventions dedicated to assisting individuals in managing stress and negative emotions often necessitate substantial time commitments. This can be burdensome for users, leading to high dropout rates and reducing the effectiveness of these interventions. This highlights an urgent need for concise digital activities that individuals can swiftly access during instances of negative emotions or stress in their daily lives. OBJECTIVE: The primary aim of this study was to investigate the viability of using a brief digital exercise, specifically a reflective questioning activity (RQA), to help people reflect on their thoughts and emotions about a troubling situation. The RQA is designed to be quick, applicable to the general public, and scalable without requiring a significant support structure. METHODS: We conducted 3 simultaneous studies. In the first study, we recruited 48 participants who completed the RQA and provided qualitative feedback on its design through surveys and semistructured interviews. In the second study, which involved 215 participants from Amazon Mechanical Turk, we used a between-participants design to compare the RQA with a single-question activity. Our hypotheses posited that the RQA would yield greater immediate stress relief and higher perceived utility, while not significantly altering the perception of time commitment. To assess these, we measured survey completion times and gathered multiple self-reported scores. In the third study, we assessed the RQA's real-world impact as a periodic intervention, exploring engagement via platforms such as email and SMS text messaging, complemented by follow-up interviews with participants. RESULTS: In our first study, participants appreciated the RQA for facilitating structured reflection, enabling expression through writing, and promoting problem-solving. However, some of the participants experienced confusion and frustration, particularly when they were unable to find solutions or alternative perspectives on their thoughts. In the second study, the RQA condition resulted in significantly higher ratings (P=.003) for the utility of the activity and a statistically significant decrease (P<.001) in perceived stress rating compared with the single-question activity. Although the RQA required significantly more time to be completed (P<.001), there was no statistically significant difference in participants' subjective perceived time commitment (P=.37). Deploying the RQA over 2 weeks in the third study identified some potential challenges to consider for such activities, such as the monotony of doing the same activity several times, the limited affordances of mobile phones, and the importance of having the prompts align with the occurrence of new troubling situations. CONCLUSIONS: This paper describes the design and evaluation of a brief online self-reflection activity based on cognitive behavioral therapy principles. Our findings can inform practitioners and researchers in the design and exploration of formats for brief interventions to help people with everyday struggles.

Collaborative Health Reminders and Notifications: Insights from Prototypes.

We designed five novel collaborative health reminders using data-driven low-fidelity prototyping methods. Each collaborative reminder-Symbolic Reminder Band, Social Reminder App, Reminder Invitation, Conversation Reminder, and Actionable Notification-was designed for patients to engage, discuss, and share their health information for collaboration on health tasks. We conducted evaluations with 11 patients and caregivers: six patients with type 2 diabetes, and five mothers of children with asthma. We found that participants valued these reminders for enhancing the patient-provider relationship, supporting shared action on health tasks, and promoting social support. We contribute design implications for collaborative health reminders that enhance patient-centered care.

Persuasive Reminders for Health Self-Management.

Health reminders are integral to self-managing chronic illness. However, to act on these health reminders, patients face many challenges, such as lack of motivation and ability to perform health tasks. As a result, patients experience negative consequences for their health. To investigate the design of health reminders that persuade patients to take action, we conducted six participatory design sessions with two cohorts: mothers of children with asthma, and older adults with type 2 diabetes. Participants used collages, storyboards, and photos to express design ideas for future health reminder systems. From their design artifacts, we identified four types of persuasive reminders for health self-management: introspective, socially supportive, adaptive, and symbolic. We contribute insights into desired features for persuasive reminder systems from the perspectives of patients and informal caregivers, including features that support users to understand why and how to complete health tasks ahead of time, and affordances for intra-familial and patient-provider collaboration.

Understanding patients' health and technology attitudes for tailoring self-management interventions.

Healthcare providers are moving towards tailoring self-management interventions to include the communication technologies patients use in daily life. Accurate understanding of patients' attitudes towards both technology and involvement in managing chronic conditions will be critical for informing effective self-management strategies. The tailoring of these interventions, however, could be undermined by providers' implicit biases based on patient age, race, and education level that have been shown to negatively affect care. To inform the design and tailoring of self-management interventions, we elicited attitudes toward technology use and participation in care of 40 participants in a maximum variation sample. The analysis revealed three participant clusters-"Proactive Techies," "Indie Self-Managers," and "Remind Me! Non-Techies"-that represent varying attitudes toward health behaviors and technologies that were independent of race, education level, and age. Our approach provides insight into how people prioritize important values related to health participation and technology.

Shared Calendars for Home Health Management.

What is the role of shared calendars for home health management? Utilizing a maximum variation sampling method, we interviewed 20 adult individuals with diabetes and 20 mothers of children with asthma to understand calendar use in the context of chronic disease home health management. In comparing the experiences of these two groups, we explore participants' use of tools for organizing tasks and appointments, their strategies for capturing health and non-health events in the family calendar system, the ecology of artifacts that intersect with their scheduling tools, and the failures they experienced while managing their calendar systems. Through this work, we offer a context-specific perspective of schedule management strategies for individuals and families who must integrate their handling of chronic illnesses with everyday living.

Understanding Design Tradeoffs for Health Technologies: A Mixed-Methods Approach.

We introduce a mixed-methods approach for determining how people weigh tradeoffs in values related to health and technologies for health self-management. Our approach combines interviews with Q-methodology, a method from psychology uniquely suited to quantifying opinions. We derive the framework for structured data collection and analysis for the Q-methodology from theories of self-management of chronic illness and technology adoption. To illustrate the power of this new approach, we used it in a field study of nine older adults with type 2 diabetes, and nine mothers of children with asthma. Our mixed-methods approach provides three key advantages for health design science in HCI: (1) it provides a structured health sciences theoretical framework to guide data collection and analysis; (2) it enhances the coding of unstructured data with statistical patterns of polarizing and consensus views; and (3) it empowers participants to actively weigh competing values that are most personally significant to them.

Systematic inquiry for design of health care information systems: an example of elicitation of the patient stakeholder perspective.

The electronic health record (EHR) has evolved as a tool primarily dictated by the needs of health care clinicians and organizations, providing important functions supporting day to day work in health care. However, the EHR and supporting information systems contain the potential to incorporate patient workflows and tasks as well. Integrating patient needs into existing EHR and health management systems will require understanding of patients as direct stakeholders, necessitating observation and exploration of in situ EHR use by patients to envision new opportunities for future systems. In this paper, we describe the application of a theoretical framework (Vicente, 1999) to organize qualitative data during a multi-stage research study into patient engagement with EHRs. By using this method of systematic inquiry, we have more effectively elicited patient stakeholder needs and goals to inform the design of future health care information systems.