A housing for a hand-held electronic device and a corresponding method for forming the same are provided. A plurality of patient retention straps are coupled to the plastic sheet and are configured to secure a patient in the plastic sheet when the plastic sheet is curved upward about the patient. The control circuit also includes a summing circuit responsive to an output of the differentiator circuit and a step function signal. The alloy is heat-treated at a sufficient temperature to achieve stress relief. The present invention provides for an efficient technique to evaluate three dimensional data.