6.__Liability.__A physician, physician's assistant, registered nurse, person certified by the Department of Human Services or hospital or other health care provider in the exercise of due care is not liable in damages or otherwise for any act done or omitted in performing the act of collecting or withdrawing specimens of blood at the request of a law enforcement officer pursuant to this section.

7.__Evidence.__The percentage by weight of alcohol in the defendant's blood at the time alleged and the concentration of drugs at the time alleged, as shown by the chemical analysis of the defendant's blood, breath or urine or by any test authorized by subsection 5 is admissible in evidence.

A.__When a person certified under subsection 5 conducts a chemical analysis of blood, breath or urine to determine blood-alcohol level or drug concentration, the person may issue a certificate stating the results of the analysis.__ That certificate, when duly signed and sworn to by the certified person, is admissible in evidence in any court of the State.__It is prima facie evidence that the person taking a specimen of blood or urine was a person authorized by subsection 5; that the equipment, chemicals and other materials used in the taking of the blood or urine specimen or a breath sample were of a quality appropriate for the purpose of producing reliable test results; that any equipment, chemicals or materials required by subsection 5 to be approved by the Department of Human Services were in fact approved; that the sample tested by the person certified under subsection 5 was in fact the same sample taken from the defendant; and that the drug concentration or percentage by weight of alcohol in the defendant's blood was, at the time the blood, breath or urine sample was taken, as stated in the certificate, unless with 10 days' written notice to the prosecution, the defendant requests that a qualified witness testify as to any of the matters as to which the certificate constitutes prima facie evidence.__ The notice must specify those matters concerning which the defendant requests testimony.

B.__A person certified under subsection 5 as qualified to operate a self-contained, breath-alcohol testing apparatus to determine the blood-alcohol level may issue a certificate