Importance of Linguistic Details in Alarm Messages of Ventricular Assist Devices

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.

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.

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

Ventricular Assist Devices (VADs) provide continuous mechanical circulatory support during in- and out-of-hospital care. However, limitations of the external wearable components influence patient quality of life. There is insufficient understanding of the issues with such components that combines a holistic viewpoint from both human factors and user (including patient and caregiver) experience perspectives. This paper comprehensively details the issues with VAD wearable systems and proposes a way for human-centered design to bridge the gap, addressing such issues synergistically. Through the review the authors investigated: the user issues caused by wearable components of VADs, and how human factors issues correlate to the VAD user experience. A Boolean search ("ventricular assist" AND "human factors" AND "experience") for peer-reviewed studies published between 2008 and 2018 returned 338 titles, with 35 relevant studies selected using a PRISMA process for inclusion in cross-study analysis and synthesis. This paper provides design recommendations for the issues found in the literature. Four key focus areas to inform the future design of VAD wearable components were identified-'Power Supply', 'Wearability and Travel Freedom', 'The Female Experience' and 'Intuitive Handling'. Using design to drive innovation could result in VAD wearable components which better meet or exceed users' quality of life goals.

Usability of ventricular assist devices in daily experience: a multicenter study

In daily life, the safe, intuitive use of ventricular assist devices (VADs) and especially their peripheral components is not only a question of life quality, but also sometimes crucial for survival. To investigate the advantages and disadvantages of different systems and to get patient feedback on preferred features, a multicenter study was initiated. Based on previous single-center studies, a questionnaire was developed to ascertain patients' experiences, difficulties with, and desires concerning use of the system. This questionnaire was provided both to ongoing patients and to new VAD patients after a minimum hospital discharge time of 6 weeks, at a regular checkup. Additionally, the patients completed a standardized questionnaire on life quality (Kansas City Cardiomyopathy Questionnaire). The centers that contributed to this study were Bad Oeynhausen, Berlin, Hannover, and Vienna. Three hundred fifty-two completed questionnaires on eight different pump types were obtained. An important result is that 42% of those questioned dropped their controller bag at least once. Depending on the device, between 2 and 55% disconnected it unintentionally. Confidence in safe use of the system decreased significantly with age, from 80% at age 20-30 years to 33% at 70-80 years. In devices with an LCD display, 94% considered the readability sufficient. Ninety-four percent considered the training adequate. Between 22 and 88% of the patients called the emergency telephone hotline, depending on the device, and 23-46% depending on the center. This first multicenter study on VAD usability reveals considerable differences among devices and centers. The comparative assessment aims to help optimize device design, patient management, and training.

Outpatient management of intra-corporeal left ventricular assist device system in children: a multi-center experience

Little is known about the outcomes of children supported on intracorporeal left ventricular assist device (HVAD), and the feasibility of outpatient management. All centers with pediatric patients discharged from the hospital on the device were identified using company database. A total of 14 centers were contacted, with 9 centers, contributing data retrospectively. From 2011 to 2013, 12 pediatric patients (7 females), mean aged 11.9 ± 2.3 years (range 8-15), mean weight 43 ± 19 kg (range 18-81), mean body surface area 1.3 ± 0.3 m(2) (range 0.76-1.96) were identified. Diagnosis included: dilated cardiomyopathy (CMP) (n = 5), noncompaction CMP (n = 4), toxic CMP (n = 2) and viral CMP (n = 1). Indications for support were permanent support (n = 1), bridge to recovery (n = 1) and bridge to transplantation (n = 10). Prior to HVAD implantation, all patients received intravenous inotropes and two patients were on temporary mechanical support. Overall mortality was 0%. Mean duration of inpatient and outpatient support were 56 (range: 19-95 days) and 290 days (range: 42-790), respectively. Mean readmission rate was 0.02 per patient month (2.1 per patient). No adverse events involving emergency department occurred. Eight children resumed local schooling. Home discharge of children supported on HVAD is feasible and safe. School integration can be achieved. There is wide center variability to discharge practice for children.