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Usability Survey of Medical Devices Used in ICU

Design Research / Article 2.

Feb. 2008, HCI Vistas Vol-IV

Authors: Ganesh Bhutkar, Dinesh Katre, N. R. Rajhans

Abstract

This article briefly presents the findings of our initial survey conducted to identify the usability issues of selected medical devices used in Intensive Care Unit (ICU). Our main objective is to understand the human factors and the perception of medical practitioners. The data is gathered through questionnaires, user interviews and fieldwork. The findings reveal the alarming need to address usability issues of medical devices used in ICU. Our future explorations will focus on identifying the usability guidelines and solutions to specific usability problems.

Introduction

[This article is extracted from our full length research paper “Ergonomic Issues of Computer Based Products Used in Intensive Care Unit” presented at the Conference on Humanizing Work and Work Environment (HWWE) 2007, Bhopal, India. The paper includes photographs of devices and details of the survey. The lead author would like to get in touch with people working on medical usability.]

Research in medical usability cuts across multiple disciplines like Human Computer Interface (HCI), Medical Science, Ergonomics, Electronics, Computer Science etc. Today, as hospitals are going for more automation with sophisticated equipment, machinery and computer software; medical usability is becoming far more relevant and critical factor. Interfaces of medical devices must focus on efficiency, ease of use, accuracy and goal fulfillment. Otherwise, it can result in wrong medication being dispensed to patients. It is a matter of life or death.

Survey

  • Selection of Medical Devices

There are many medical devices like ventilator system, defibrillator, multi-parameter monitoring system, central monitoring station, Electrocardiogram (ECG) analyzer etc. All such devices support the emergency diagnosis, observations and therapies in ICU. In this survey, three devices were included: - multi-parameter monitoring system, ECG analyzer and ventilator system. A multi-parameter monitoring system is used for monitoring of invasive or noninvasive pressures, ECG, Electroencephalogram (EEG), arrhythmia analysis, arterial oxygen saturation etc. The ECG analyzer helps in monitoring and analyzing the ECG tracing to provide and store full diagnostic reports periodically. A ventilator system gives respiratory support to critically ill patients. These are most critical and commonly required medical devices, which provide extensive information in ICU; so their selection becomes a necessity.

  • Hospitals

The research was conducted in seven ICUs belonging to different hospitals in India. The hospitals visited for this medical usability survey include four hospitals in Pune city namely Bharati Hospital, Sahyadri Hospital, Ratna Memorial Hospital and Siddhi Hospital; two hospitals around Pune city namely Giriraj Hospital from Baramati; Jogalekar Hospital from Shirwal and People€™s Group Hospital from Bhopal, Madhya Pradesh. It was very hectic and tricky challange to get access to medical practitioners in the ICU.

  • Users

Different types of users are considered in this research. The primary users (who actually use the devices) include ICU physicians, specialized physicians, resident doctors and sisters. The secondary users (who assist the primary users or help in maintaining the devices) include intern doctors, ward boys, biomedical technicians and patients. The tertiary users (who come in proximity of devices knowingly or unknowingly and are affected by them indirectly) include administrators, relatives of patients, visitors etc. We have tried to sample some subsets of these users.

  • Research Methods

Three research methods are used in this survey namely a questionnaire, interviews, field visits. The questionnaire has two sections. First section is about personal data like name, age, sex, height, left or right handed dexterity, education, organization, products used, frequency of usage etc. Second section of the questionnaire covers user response on different aspects of usability. The users were interviewed before filling up the questionnaire. Fieldwork included frequent visits to ICUs from different hospitals and observation of users while operating the medical devices.

Usability Issues

Some of the usability issues commonly observed during this survey are discussed here.

  • Switches don’t last, instructions and icons fade away

The ventilators are costly and have to be used for longer duration to recover the investments. But users’ experience is contrary. The switches, knobs and control panels don’t last that long due to frequent use. The labels and symbols printed on the buttons fade away.

  • Right-handed design

Most ventilator systems are designed only for right-handed users. It is reflected by the layout of control panels. Such design may not prove effecient for left-handed users. Users complained about improper arrangement and spacing of controls and switches.

  • Poor readability and contrast

Some users feel that multi-parameter monitoring systems have poor readability. Due to reflected light, the numerical readings are not visible in ventilator systems. Technicians feel that aging factor of both systems and the users can complicate the readability and contrast issues with monitors of these systems.

  • User manuals in foreign languages

During the interview, many sisters, intern doctors and ward-boys reported that the user manuals are difficult to locate when needed or manuals are not accessible because they are in custody of some authority. User manuals are not readable for them as the information is presented in many foreign languages like English, French, Dutch etc. User manuals need to be provided in Indian languages like Hindi and other regional languages. The ventilators can also afford to provide online-help.

  • Too many unused features

Most users feel that there are extensive functionalities provided with both ventilator systems and multi-parameter monitoring systems. Many of these functionalities are underutilized and some of them cause cognitive load to the user.

  • Culture specific icons

Users feel that interface labels, symbols and abbreviations are cultural specific. They need to be localized. Some users feel that there is a need for standardization of symbols and abbreviations.

  • Complex data entry mechanism

The devices like multi-parameter monitoring systems and ECG analyzers have an interface to enter patient data. But most users find the entry steps to be cumbersome and time-consuming. So they rarely use data entry facility.

  • Lack of templates and intelligence

Users feel that medical devices like ventilator systems should be more intelligent to support error recovery and self-diagnosis. Medical devices should support use of defaults or templates to guide secondary users and sisters to handle some specific situations. The alarms informing different conditions should be differentiated.

  • Portability

Usually the accessories are complex. Many vendors have monopolistic approach about accessories and their consistent availability can be doubtful. The probes are delicate and they need to be sturdier. Most of the users feel that ventilator systems need to be more compact with a robust design to support mobility, portability and storage. Especially, dismantling of ventilator stand is time-consuming.

  • Training the assistive staff

Need for training on medical devices for the assistive staff is strongly felt by the physicians. The assistive staff have tentative knowledge and they learn by trial and error. Due to lack of training, many functions may remain hidden and unused. Physicians feel that due to busy schedule they can not train the assistive staff. This sums up the feedback and our initial observations. Users from seven different ICUs participated in our survey. Following graph shows the common trends in the user responses. Higher the height of the bar greater is the concern. Broadly, the users are more concerned about training, user manuals, portability, functionality, labels and symbols.

Graph 1: User Response

Increasing demand for training and better user manuals reveals users’ helplessness in understanding the controls and interface. It indicates the alarming need to focus on overall usability of medical devices.

Conclusion

The study and observations discussed so far evidently show major scope for enhancing the medical devices from usability perspective. Considering the life criticality and the impact of design on users like ICU patients, sisters and physicians, the proposed enhancements must be accorded highest priority.

References

1. Chauncey E. Wilson. Designing useful and usable questionnaires: you can’t just throw a questionnaire together; ACM Interactions; May-June 2007; 48-49, 63.

2. Dick Sawyer: An introduction to human factors in medical devices, US Department of Health and Human Services, Dec 1996.

3. Jakob Nielson: Medical usability: how to kill patients through bad design; Alert box, April 11, 2005.

4. Vela Ventilator Systems, Operator’s Manual, VIASYS Healthcare, May 2004; Rev. E.

Newspaper report based on this article:

Use of medical devices by hospital staff under scanner, Indian Express, 17 March 2008.

The news report is further published by international sites-

British HCi Group

Ergonomics In The News

Ganesh Bhutkar is Computer Engineering and Management postgraduate and currently pursuing PhD in Medical Usability. He is an Assistant Professor at VIT, Pune, India. He has published about 10 research papers and associated with some International Journals as associate editor and reviewer. Contact: ganesh.bhutkar@vit.edu

Dr. Dinesh Katre presently heads the National Multimedia Resource Centre of C-DAC, Pune, India. He is the principle designer of many software products that deal with digital library, cultural informatics, e-learning, multimedia authoring and computer game design. He has special interest in the cognitive study of technology users and behavioral design of products. Journal of HCI Vistas is his community building initiative. It is meant to promote research oriented, multi-disciplinary thinking in the field of Human-Computer Interaction. This e-publication is open for usability practitioners and UX designers to publish short articles.

Dr. N. R. Rajhans completed her PhD in Industrial Engineering in 2005. She is Professor at VIT, Pune, India. Her areas of interest are operational research and ergonomics. She has 20 years of academic experience and 15 research papers. She is associated with Institution of Engineers Journal (Production and Interdisciplinary Section) as Referee.

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