HSD assisted in the redesign of the Twisthaler device. The criterion of the redesign was to prevent the patient from overdosing or overusing the inhaler. In order to fulfill this purpose, HS Design developed a feature where upon removal of the cap, the device was cocked; followed by patient inhalation. To actuate the unit again, the cap must be repositioned; thus preventing patients from double dosing. A counter was built in to the device, which would count down to create the internal reaction that produced the vapor.

HSD used its experience in industrial design and engineering to meet the redesign constraints of the Twisthaler. More specifically, the innovative lockout feature was key to the success of the design.