The design of a breakthrough patient-care cart to be used by nurses and doctors presented the engineers at Howard Medical, Ellisvills, MS, with a mechanical nightmare. Dozens of innovative new functional features needed to be included on the compact, lightweight, and easy-to-maneuver Hi-Care cart.

Achieving that required making ergonomics and usability top priorities without compromising the introduction of new technologies such as personalized electronic patient records and computer verified medicine distribution. After initial engineering by Howard engineers, the company recognized the need for bringing in an industrial design firm—Tanaka Kapec Design Group, Inc, Norwalk, CT—to move the project through the phases leading up to product introduction (2006).

The industrial design strategy included field research with the nurses and doctors who would use the cart, collaborating with engineers to organize the components so the cart would meet functional and ergonomics requirements, and assisting with the manufacturing strategy. The design would need to balance the needs of ergonomics and user interaction with functionality, outward appearance, serviceability, and manufacturability.

Focus on nurses

TKDG’s user research concentrated on nurses, some of whom would be using the cart to complete upwards of 100 tasks during the course of an 11-hour shift. The research also considered the needs of physicians who would use the cart routinely, but for different tasks and for shorter periods. By observing users in action, the need for several features that would complement the core technology was uncovered. These ran the gamut from things as apparent as introducing a height adjustment feature to account for the different statures and personal preferences of users to less obvious features such as adding a place to rest the foot so nurses could keep their back straight while standing as they use the cart during patient rounds.

Observing how nurses respond to emergencies drove home the importance of making the cart subservient to the nurse and patient. To illustrate, while responding to an emergency, a nurse was observed pushing open a heavy hospital room door with one hand while pulling the cart with the other. To do this with a competitor’s cart she had to contort her hand, which was pulling the cart. This demonstrated how important it was to have a base and wheels that wouldn’t interfere with the user’s feet and a comfortable way to hold and pull the cart.

User research revealed that nurses wanted an extra large work surface that, with the height adjustment feature, would enable them to use the cart as a workstation while they were sitting down to complete reports and other documentation at the end of the day.

The need for a foot rest that nurses and doctors could use to keep their backs straight while standing next to the HI-Care cart was identified and designed in by Tanaka Kapec Design Group. Designers also included a height adjustment feature (below), operated by an internally mounted actuator, so the cart would be fit the stature of all nurses and doctors, regardless of their height or personal preferences.

Other ergonomic features that were ultimately added based on observing potential users included a battery drawer in the base of the cart that would make replacing batteries quick and easy, and a keyboard drawer just below the work surface that could slide easily without requiring much clearance. Other less tangible aspects of product design include shaping the keyboard and surface in the central section to create a styling that made the cart appear smaller than its physical dimensions.

From 12 to 1

Twelve computer-rendered design concepts led to six design models. Each design model had its own unique combination of features and aesthetic form factor. Then 12 working prototypes were built with low-volume plastic parts to make each look like an end product.

The prototypes were taken back into the field to get feedback from many of the nurses and doctors who were observed and interviewed in the first-phase field research. Based on this second-round feedback, Howard engineers and TKDG designers finalized the organization of components on the cart. In addition to developing engineering drawings for the chassis and subassemblies, TKDG industrial designers used CAD to create the complex curved surfaces that would enhance the ergonomics and make the cart more visually appealing. Howard engineers worked on the methods of assembly, software, battery management, advanced charging systems, and requirements for long-term reliability.

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