NDI provides optical and electromagnetic measurement systems for medical and industrial applications.

NDI’s technology is used for the growing fields of computer-assisted surgery, computer-assisted therapy and image-guided radiation treatment.

In addition, the company’s technology is used by advanced manufacturers for optical tracking and non-contact 3-D measurements.

Northern Digital’s management team, under the leadership of Jamie Fraser, will continue to lead the business as part of Roper.

Completion of the transaction is expected in June 2011 following regulatory approval and customer closing conditions.