What is the legal test for objecting to an instruction in a medical malpractice case?

^7.Gonzalez did not object at trial to the instruction on the ground he now raises on appeal. However, because he contends "the instruction is not 'correct in law,' and that it violate[s] his right to due process of law[,] the claim . . . is not of the type that must be preserved by objection." (People v. Smithey (1999) 20 Cal.4th 936, 976, fn. 7; see, also, 1259 ["The appellate court may . . .review any instruction given, . . . even though no objection was made thereto in the lower court, if the substantial rights of the defendant were affected thereby."].)