According to the NIH, waist measurements can be used to screen for possible health risks to overweight or obese patients. A medical researcher at a leading academic medical center was looking for a waist measurement device that would eliminate inter-operator variability while capturing accurate, repeatable waist measurements from the entire waist area, from the ribs to the hips. The design needed to be low-cost, compact, lightweight, and intuitive to use.

NOVO developed several concepts from which one was selected by the development team to advance into feasibility testing. In the selected design, five straps encircle the entire waist area, from the ribs to the hips. The straps unspool from reels inside a housing on the back of the device and extend completely around the waist when the patient zips up the front closure on the device.

A means for automatically measuring the length of the extended straps based on optical sensors was developed along with custom electronics to read the sensors, manage digital I/O, and handle communications. The feasibility hardware transmits output data over a USB interface, which would be replaced with an RF connection in a product implementation. The data can be made available to the patient through a mobile application, or to a treatment provider via the web.

NOVO engineers worked with a soft goods manufacturer to finalize the design. The system was calibrated using tubes of known diameter and tested on engineers of various body types before final testing took place on site at the client’s facility.