Human Factors and User Experience Issues with Ventricular Assist Device Wearable Components: A Systematic Review

Human Factors Evaluation of HeartMate 3 Left Ventricular Assist Device Peripherals: An Eye Tracking Supported Simulation Study

BACKGROUND

Despite recent design improvements, human factors issues continue to challenge left ventricular assist device (LVAD) therapy. The aim of this study was to evaluate user experience of former non-HeartMate 3 (HM3) LVAD patients post heart transplantation (HTX) and laypersons (LP) with HM3 LVAD peripherals in simulated everyday and emergency scenarios.

METHODS

This single center cohort study included untrained HTX and LP. Seven scenarios, including battery exchanges (without alarm, advisory alarm, dim light, consolidated bag), change of power supply, driveline dis-/reconnection and controller exchange were simulated. Subjects' gaze behavior was recorded using eye tracking technology. Success rate, pump-off-time, duration to success (DTS), percental fixation duration per areas of interest and post-scenario-survey results were defined as outcome measures.

RESULTS

Thirty subjects completed 210 scenarios, initially solving 82.4% (HTX vs. LP, p = 1.00). Changing power supply revealed highest complexity (DTS = 251 ± 93s, p = 0.76): 26.7% succeeded at first attempt (p = 0.68), 56.7% at second attempt, with significantly more LP failing (p = 0.04), resulting in 10 hazards from driveline disconnections (pump-off-time 2-118s, p = 0.25). Comparison on initial success showed differences in fixation durations for seven areas of interest (p < 0.037). Decreasing DTS during battery exchanges (p < 0.001) indicate high learnability. Exchanging batteries within the bag took longer (median DTS = 75.0 (IQR = 45.0)s, p = 0.09), especially in elderly subjects (r = 0.61, p < 0.001). Subjects with less initial success were more afraid of making mistakes (p = 0.048).

CONCLUSION

This eye tracking based human factors study provided insights into user experiences in handling HM3 peripherals. It highlights unintuitive and hazardous characteristics, providing guidance for future user-centered design of LVAD wearables.

It's not only the pump: Assessment of human factors of wearable components and user experience of patients with left ventricular assist devices

BACKGROUND

Despite design improvements in left ventricular assist devices (LVADs) over the past decade, limitations of external, wearable VAD components affect patient quality of life and safety. The aim of this study was to describe both user experience and human factor issues of 2 contemporary LVADs.

METHODS

This single-center, cross-sectional study included LVAD outpatients who were at least 3 months after implantation. Before developing the 16-item survey, a systematic literature review and 2-round Delphi method involving 9 VAD clinicians were used to select items in 6 domains: power supply, emergency situations, wearability, mobility, and freedom to travel, user modifications, lifestyle, and home adaptations.

RESULTS

Fifty-eight patients (61.6 ± 11.6 years, 13.8% female, HeartMate 3 (HM3)/HVAD: n = 39/19) completed the one-time survey after median of 853 days on device: 10.3% reported problems changing power supply, 12.7% unintentional driveline disconnection (HM3: 5.6% vs HVAD: 26.3%, p = 0.041). Against the recommendation 74.1% sleep with battery-support (HM3: 88.9% vs HVAD: 44.4%, p = 0.001). About 65.3% criticized the carry bag weight/size (HM3: 71.4% vs HVAD: 50.0%, p = 0.035), thus 24.1% wear an own carrying-system, 42.1% modified their wearables, 38.9% their clothing, and 65.3% their home to cope with life on LVAD support. Mobility is reduced due to limited wearability: 18.9% went abroad (only 3.7% by plane) and 40.0% use less public transport than before implantation (the older the less: r = -0.37, p = 0.013).

CONCLUSIONS

HVAD and HM3 wearables still show a variety of human factors issues and potential for improved user experience. User-centered design and incorporation of patient feedback may increase user satisfaction, and patient safety.

Psychological burden and coping in destination therapy patients with a left ventricular assist device: a qualitative content analysis

BACKGROUND

Due to an increasing prevalence of heart failure and persistent shortage of donor hearts, the number of left ventricular assist device (LVAD) implantations is growing. As more patients live with LVADs for prolonged periods of time, psychosocial outcomes are becoming more relevant. This particularly applies to destination therapy (DT) patients, who live with the LVAD for the rest of their lives.

METHODS

We used a cross-sectional qualitative design to explore psychological burden, coping strategies and resources from the perspective of DT patients. Data was collected via semi-structured in-depth interviews with 18 patients who lived with the LVAD for 3 months to over 10 years. These were analyzed using an inductive content analysis. Due to the COVID-19 pandemic, changes to the recruitment strategy and data collection strategies of the original study protocol were applied. Patients and clinicians were involved throughout the research process to ensure validity of the results and implications.

RESULTS

We synthesized 10 psychosocial, health, and treatment-related burdens, identified 15 problem- and emotion-focused coping strategies and 5 personal and environmental resources patients used to cope with the burden.

CONCLUSIONS

The findings provide deeper insights into the complex and specific situation of LVAD patients to better address the patient situation in health care and promote positive psychosocial outcomes. So far, health care practice and quality vary significantly between clinics due to individual treatment protocols. Our results highlight the need to improve medical and psychosocial care. Overarching care concepts may be developed based on the implications.

Patient names for mechanical circulatory support devices: Developing emotional insights

BACKGROUND

Patients with mechanical circulatory support devices regularly experience positive and negative emotions which are reinforced through interactions with their device. We explored emotional relationships between patients and their MCS devices through the names they assign to those devices.

OBJECTIVES

We sought to characterise device naming and suggest future developments which might capitalise on the naming phenomenon to improve patient wellbeing.

METHODS

Qualitative online ethnography extracted comments on device names and emotions from a social media group. Thematic analysis grouped the comments according to their explicit or implied emotions, and their potential consequences for designing future MCS treatment.

RESULTS

Thematic analysis identified 28 codes to characterise the names, from which we inferred 4 main themes for proposed emotional relationships. They centred on humour, coping, improving acceptance for family and friends, and reclaiming agency.

CONCLUSION

We suggest that by deliberately considering these factors in future research and development, clinicians and device manufacturers have scope to improve patient wellbeing.

Eye Tracking Supported Human Factors Testing Improving Patient Training

The handling of left ventricular assist devices (LVADs) can be challenging for patients and requires appropriate training. The devices' usability impacts patients' safety and quality of life. In this study, an eye tracking supported human factors testing was performed to reveal problems during use and test the trainings' effectiveness. In total 32 HeartWare HVAD patients (including 6 pre-VAD patients) and 3 technical experts as control group performed a battery change (BC) and a controller change (CC) as an everyday and emergency scenario on a training device. By tracking the patients' gaze point, task duration and pump-off time were evaluated. Patients with LVAD support ≥1 year showed significantly shorter BC task duration than patients with LVAD support <1 year (p = 0.008). In contrast their CC task duration (p = 0.002) and pump-off times (median = 12.35 s) were higher than for LVAD support patients <1 year (median = 5.3 s) with p = 0.001. The shorter BC task duration for patients with LVAD support ≥1 year indicate that with time patients establish routines and gain confidence using their device. The opposite effect was found for CC task duration and pump-off times. This implies the need for intermittent re-training of less frequent tasks to increase patients' safety.

A systematic review of psychosocial design considerations for the next generation of mechanical circulatory support

BACKGROUND

Biomedical engineers are developing new mechanical circulatory support pumps. Clinicians are generating and analysing new evidence for their prescription and management. Industrial designers are generating usable solutions for wearable components and controllers. However, psychosocial considerations may be falling between the cracks of the three disciplines because of their multi-faceted nature.

OBJECTIVES

This article seeks to identify psychosocial needs raised in previous work, re-frame them as needs for future products and services, and discuss routes to solutions.

METHODS

SLR extracted 225 statements on psychosocial considerations from 42 included articles. 23 codes were inductively generated and applied to relevant datapoints. Codes were consolidated under 4 main themes and re-framed as solvable problems.

RESULTS

Identified themes: expanded remote care, improved multidisciplinary management tools, creating easier interactions; and extending patient engagement.

CONCLUSIONS

Design-driven methods have been used to solve analogous problems in other contexts and can address the identified psychosocial problems if implemented fully.