Biomedical Engineering Analysis of an Electrocution Expert Article

This article discusses the process by which it is possible to reconstruct an incident by examining injury data. In this instance, our biomedical engineer was tasked with determining the manner in which the deceased encountered the electrical source.

Biomedical Engineering Investigation of an Unwitnessed Electrocution

A woman is found lying on the ground in her own yard while in contact with a live power line that had fallen. The event is unwitnessed and the female later dies of 3rd and 4th degree burns to over half of her body. Did she grab the power line? Did the power line fall on her? There was no dispute that the injuries were related to the incident, but our client’s legal strategy required knowledge of the manner in which the person encountered the power source.

This type of injury causation analysis falls under the purview of biomedical engineering. Biomedical engineering is the application of classical mechanical, electrical and chemical engineering toward the understanding of the human body as a whole system as well as the individual systems, organs, tissues and cells.

Electricity is the flow of electrons across a potential gradient from high to low concentration through a conductive material. Current is comprised of electrons and is what can kill or hurt people.

The mechanism, extent, and depth of an electrical injury are determined by:

• The voltage
• The amount of current
• The duration of current
• The pathway of the current
• The resistance
• The type of current (ie. direct current – DC or alternating current – AC)

The National Electrical Code considers low voltage to be less than 1,000 volts and high voltage to be above 1,000 volts.¹ High voltage exposure (greater than 1000V AC) that is not immediately fatal does not necessarily cause loss of consciousness, but instead causes devastating thermal burns.^2,3

Alternating current causes muscle tetany (sustained, uncontrolled, involuntary, unsynchronized contraction of muscles) due to the cyclic flow of electrons. This muscle tetany can cause prolonged exposure to the source because the muscle fibers are stimulated causing contraction. In addition to skeletal muscle and nerve damage, injuries from electrical contact can include bone fractures and joint dislocations.

Burns from electric current present as contact wounds from contact with the energized source and from contact with the “grounding location." These contact wounds have specific appearances and create a particular injury pattern. 

Injury Causation Analysis

An injury causation analysis can often determine what happened in an unwitnessed event and can also verify whether or not events took place as described by witnesses. It can also be used to determine if the use/misuse of protective equipment played a role in the cause of an injury.

Our biomedical engineers often work in conjunction with our electrical engineers, who routinely investigate incidents related to electrical equipment/systems, including claimed product malfunctions, electrical fires and utility company operations. 

In the case of the incident unwitnessed electrocution, our expert was able to investigate the injury pattern described and depicted in the medical records and autopsy and apply knowledge of the mechanisms of electrical injuries to demonstrate that the person did not grab the live power source with either hand.

Instead, the power line had fallen onto the person’s left upper arm and thus the deceased’s actions did not initiate or contribute to the electrocution event. This, in turn, enabled our client to show that the deceased was not contributorily negligent.

An injury causation analysis can be applied to any type of incident, whether it involves sports, automobile crashes, industrial mishaps, or slips and falls. If your case strategy calls for an understanding of the injury mechanisms, our biomedical experts at Robson Forensic can discuss your case with you to determine how we can help.

Biomedical/Biomechanical Engineering Investigations

The biomedical experts at Robson Forensic provide scientific and analytical evaluation of injuries to determine causation. Our experts are engaged when the cause or mechanism of an injury is not known, is not understood, or is in dispute. Injuries tell a story. Could a fall have occurred as testified? Were the forces high enough to have caused the injuries claimed? Was the known mechanism (direction and type of loading) of injury provided in the event? Is the injury consistent with the physical evidence? These are examples of questions our biomedical/biomechanical experts can help investigate.

For more information, submit an inquiry or call us at 800.813.6736.

Sources

1. NFPA 70 - National Electrical Code – 2020 Article 490
2. Zemaitis MR, Foris LA, Lopez RA. and Huecker MR. Electrical Injuries. [Updated 2023 Jul 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK448087/
3. Hunt JL, Soft tissue pattern in acute electric burns, Chapter 4 in Electrical Trauma: The Pathophysiology, Manifestations and Clinical Management, RC Lee, EG Cravalho, JF Burke. New York: Cambridge University Press, 2011. 84-86. Print.

Featured Expert

Valentina Ngai, Ph.D., P.Eng.

Biomedical Engineer & Biomechanics Expert

Dr. Ngai is an expert in biomechanical engineering. She provides investigations, reports, and testimony toward the resolution of disputes and litigation involving traumatic injuries including medical… read more.