8th Circuit Upholds Exclusion of Engineer's Testimony in Design Defect Suit

The Eighth Circuit has published an opinion upholding the exclusion of plaintiff's engineering testimony in a products liability suit involving a worker whose arm was mangled in a sander. From the opinion:

Our cases do not require that experts manufacture a new device or prototype in order for their opinion to be admitted. The question is whether the expert's opinion is sufficiently grounded to be helpful to the jury. We conclude that Dr. Kvalseth's proffered opinion lacked indicia of reliability for other reasons. Although he proposed using a safety trip cord, a commonly used device, he did not prepare drawings showing how it would be integrated into the Timesavers sander or present photographs showing its use with similar machines. See Dancy v. Hyster, 127 F.3d 649, 651-52 (8th Cir. 1997) (excluding testimony of expert who had not designed proposed safety device or pointed to its use on similar machines). Dr. Kvalseth provided even less information about how the brake would function. An expert proposing safety modifications must demonstrate by some means that they would work to protect the machine operators but would not interfere with the machine's utility. See Jaurequi v. Carter Mfg. Co., 173 F.3d 1076, 1084 (8th Cir. 1999); Peitzmeier, 97 F.3d at 297.

See Unrein v. Foley-Martens Co., No. 04-1042 (8th Cir. Jan. 10, 2005) (Murphy, Lay, & Melloy, JJ.).