MEMORANDUM **

The estate of William Lomax brought this action alleging strict products liability causes of action under Nevada law and excessive force claims under 42 U.S.C. § 1983 based on his death in February 2004 following an incident involving the use of a taser. Plaintiffs appeal the district court’s decisions excluding the testimony of expert Brett Woodard, granting summary judgment in favor of defendant Taser International, Inc., and granting summary judgment in favor of defendants Reggie Rader and the Las Vegas Metropolitan Police Department. We have jurisdiction under 28 U.S.C. § 1291, and we affirm.

The district court did not abuse its discretion in excluding Woodard’s testimony under Federal Rule of Evidence 702. Woodard failed to examine any relevant studies or other materials, and was unaware that any taser studies had been conducted on humans or animals. The court reasonably concluded that he lacked an objective basis for his opinion regarding the physiological effects of the taser.

Without the excluded expert testimony, plaintiffs’ evidence does not create a genuine issue of fact as to whether the taser was a substantial factor in causing Lo-max’s death. See Price v. Blaine Kern Artista, Inc., 111 Nev. 515, 893 P.2d 367, 370 (1995) (adopting the “substantial factor” test for causation in strict products liability cases). Medical examiner Ronald Knoblock did not opine that the taser was a substantial factor in causing Lomax’s death, and he testified that he had no medical or scientific evidence that a taser applied to the neck in drive-stun mode could cause the chest muscles to constrict. The timing does not alone create a genuine issue of material fact as to causation in light of Lomax’s PCP use and extensive health problems. Accordingly, we affirm *753 the grant of summary judgment in favor of defendant Taser International, Inc.

Plaintiffs have not presented evidence that a reasonable officer in Rader’s position would have known that the manner in which he used the taser would contribute to Lomax’s death or otherwise cause lasting harm. Because his “use of force was premised on a reasonable belief that such force was lawful,” Deorle v. Rutherford, 272 F.3d 1272, 1285 (9th Cir. 2001) (emphasis in original), especially as it was employed for Lomax’s benefit and resulted from the paramedics’ request, he is entitled to qualified immunity. As to LVMPD, plaintiffs do not raise any issue on appeal related to its alleged failure to train. Accordingly, we affirm the grant of summary judgment in favor of defendants Rader and LVMPD.

Because defendant LVMPD has not established that this appeal ‘Vas frivolous, vexatious, or brought to harass or embarrass the defendant,” Benigni v. City of Hemet, 879 F.2d 473, 480 (9th Cir. 1988), its request for attorney’s fees is denied.

AFFIRMED; request for attorney’s fees DENIED.