Graves v. Cas Med. Sys., Inc.

• Decision Date: 12 December 2012
• Docket Number: No. 27168.,27168.
• Citation: Graves v. Cas Med. Sys., Inc., 401 S.C. 63, 735 S.E.2d 650 (S.C. 2012)
• Court: South Carolina Supreme Court
• Parties: Kareem J. GRAVES and Tara Graves, individually and as duly appointed personal representatives of the Estate of India Iyanna Graves, Appellants, v. CAS MEDICAL SYSTEMS, INC., Respondent.

401 S.C. 63

735 S.E.2d 650

Kareem J. GRAVES and Tara Graves, individually and as duly appointed personal representatives of the Estate of India Iyanna Graves, Appellants,

v.CAS MEDICAL SYSTEMS, INC., Respondent.

No. 27168.

Supreme Court of South Carolina.

Heard Nov. 30, 2011.

Refiled Dec. 12, 2012.

Rehearing Denied Dec. 12, 2012.

J. Edward Bell, III, of Georgetown, for Appellants.

Clarke W. DuBose, of Haynsworth Sinkler Boyd, of Columbia, and Sarah Spruill, of Haynsworth Sinkler Boyd, of Greenville, for Respondent.

John S. Nichols, of Bluestein, Nichols, Thompson, and Delgado, of Columbia, for Amicus Curiae Law Professors John F. Vargo, Paul J. Zwier, II, Richard W. Wright, Frank J. Vandall, Steven A. Saltzburg, Jay M. Feinman, Thomas A. Eaton and Carl T. Bogus.

A. Camden Lewis, of Lewis, Babcock & Griffin, of Columbia, for Amicus Curiae Francis M. Wells, Professor, Emeritus, of Electrical Engineering at the Vanderbilt University School of Engineering.

Kenneth M. Suggs, Janet, Jenner & Suggs, of Columbia, for Amicus Curiae Stephen G. Pauker, M.D., Professor of Medicine.

Justice HEARN.

India Graves, a six-month-old girl, died while being monitored by one of CAS Medical Systems' products. India's parents, Kareem and Tara Graves, subsequently filed a products liability lawsuit against CAS, contending the monitor was defectively designed and failed to alert them when India's heart rate and breathing slowed. The circuit court granted CAS's motion to exclude all of the Graves' expert witnesses and accordingly granted CAS summary judgment. We affirm as modified.

FACTUAL/PROCEDURAL BACKGROUND

India and her sisters, Asia and Paris, were triplets born prematurely to Kareem and Tara. All three girls spent the first six weeks of their lives in the hospital so they could be monitored, a standard practice for premature babies. When they were finally sent home, their doctor ordered that the Graves use a monitor manufactured by CAS to track their breathing and heart rates as a precaution. The monitor was designed to sound an alarm, which, by all accounts, is quite loud, if the subject were to experience an apneic, bradycardia, or tachycardia event.¹ Once the breathing or heart rate returns to normal, the alarm stops. Each machine also keeps a log of any events, which is the term for when the alarm sounds, and records the pertinent data and vital signs.

As an additional safety measure, CAS installed not only a back-up alarm, but also a feature that records whether the alarm sounded. This system operates primarily through an independent and separate microphone specifically designed to listen for the alarm. If it hears the alarm, it then makes a notation in the monitor's internal log. If it does not hear the alarm, then it records “Front alarm not heard,” and the monitor will sound the backup alarm. A microphone listens for this back-up alarm as well and records whether it was heard. If the back-up alarm fails, all the lights on the front of the monitor flash.

On the night of April 10, 2004, India was hooked up to the monitor and fell asleep next to her father on his bed. At the time, Tara was awake doing chores.² Tara eventually moved India to her bassinet, and Tara herselfwent to sleep around 2:00 in the morning on April 11th. According to Tara, she woke up shortly before 4:00 a.m. from a bad dream and decided to go check on the babies. Paris and Asia responded to her touch, but India did not. When she realized India was not breathing, she immediately began CPR. Kareem woke up during the commotion and called 911. By the time EMS arrived, India was already dead. An autopsy revealed that she died from Sudden Infant Death Syndrome (SIDS), which essentially means that no attributable cause of death exists.

Tara and Kareem claim the monitor's alarm never sounded that night. Additionally, they testified that all the lights on the front of the monitor were on, although they were solid and not flashing. Another family member who was asleep downstairs from India also could not recall hearing the alarm go off. Tara further testified the machine was not turned off until the next day, when the monitor was removed for testing.

India's monitor recorded the following events beginning the morning of April 11th. At 2:39 a.m., the monitor first detected a slow heart beat from India. Over the next thirteen minutes, the monitor recorded twenty-three separate apnea or bradycardia events. By 2:52 a.m., India had passed the point of resuscitation. The monitor recorded six more events before showing it was powered down at 3:50 a.m. The log shows it was then powered back up the next morning. For every event, the monitor recorded hearing the alarm properly sound and accurately traced India's slowing breathing and heart rate. As India's treating physician put it, the machine's performance was tragically perfect: “[A]s sad as it is, the tracing is beautiful. It is a—you watch the baby die on the leads.”

The Graves subsequently filed a strict liability design defect claim against CAS, contending the monitor's software design caused the alarm to fail. ³ Their claim revolves around what is known as “spaghetti code,” which is when computer code is unstructured and becomes “a rather tangled mess.” Spaghetti code can result from the overuse of “goto” or “ unconditional branch” statements, which causes a signal working its way through the code to jump around instead of following a linear path. Boiled down, the Graves' theory is that certain unknown external inputs occurring during India's apneic and bradycardia events triggered some of these goto statements as the signal was being sent to sound the alarm. This in turn caused the signal to be pushed off course and never reach its destination.

To support this theory, the Graves designated three software experts to testify regarding the alarm's failure: Dr. Walter Daugherity, Dr. William Lively, and Frank Painter. In arriving at their conclusions that a software defect caused the alarm to fail, none of the experts did much actual testing of the software. Instead, they used a “reasoning to the best inference” analysis, which is similar to a differential diagnosis in the medical field where potential causes of the harm are identified and then either excluded or included based on their relative probabilities. In this case, three potential causes were identified: hardware error, complaint error, and software error. Complaint error means that the monitor was misused or the alarm did sound and the Graves failed to hear it.⁴ All the experts were able to dismiss hardware error as a cause because the machine was tested and shown to have functioned properly. Thus, the question became whether complaint error or a software error occurred.

Dr. Daugherity excluded complaint error because the machine was hooked up to India properly and he did not believe anyone could sleep through the alarm. In other words, because the Graves claim the alarm did not wake them, that means it did not go off. After being confronted with the fact that the monitor listens for the alarm and separately records whether it was heard, Dr. Daugherity accordingly concluded it “is certain” the internal logs showing the alarm sounded on the morning of April 11th are not reliable “in light of the undisputed testimony that the alarm did not function.” ⁵ Having dismissed hardware and complaint error, Dr. Daugherity ultimately concluded that software error was the most likely cause of the alleged failure based on his independent review of the code and other reported incidents of alarm failure.⁶

As to Dr. Lively, the record does not show he engaged in any analysis regarding complaint error. He did agree with Dr. Daugherity that the most likely cause was software error. In arriving at this conclusion, however, Dr. Lively relied only on Dr. Daugherity's review of the code and did nothing to search for a defect himself. In fact, he testified it was not his job to look through the code for errors, and that responsibility fell on Dr. Daugherity. He also relied on the same reports of other failures as Dr. Daugherity, but he admitted that he did not know whether these other reports had been substantiated.

Painter as well concluded a software error most probably caused the alarm to fail. He, like Dr. Daugherity, excluded complaint error because of the Graves' own statements that the alarm failed. Thus, during his deposition when he learned the monitor recorded hearing the alarm sound, Painter summarily concluded this had “no effect” on his opinion. Specifically, even though he conceded that this ordinarily would show the alarm sounded, he maintained this was not the case here “because the Graves say they didn't hear the alarm.” When explaining software error was the cause, Painter also admitted that he never examined the code in any detail and only “spent a half an hour just thumbing through it and looking at it.” In an affidavit he filed early in the case, Painter instead stated his conclusion rested on the opinions of Dr. Daugherity and Dr. Lively. In his deposition, on the other hand, Painter testified that his opinion actually was not based on the work of Dr. Daugherity and Dr. Lively, but on the reports of other alarm failures submitted to the FDA.

Finally, the Graves designated Dr. Donna Wilkins as an expert to testify whether India could have been revived had Tara or Kareem been woken up by the alarm. Although Dr. Wilkins stated she was not an expert in SIDS, it was her belief, based on her many years of experience and training as a neonatologist, that it was more likely than not Tara and Kareem would have been able to revive India had they heard an alarm. She did acknowledge no proof existed that a monitor can prevent SIDS, but from her tenure in the neonatal intensive care unit babies experiencing apneic events can be resuscitated.

CAS moved to have all the Graves' experts excluded, arguing none of them met the reliabilityfactors for scientific...