A hiker was hit by lightning and he survived. The web page below narrates the incident.
http://www.foxnews.com/us/2017/08/25/hiker-hit-by-lightning-woke-up-with-blood-everywhere.html
In this regard I had a discussion with Dr. Mary Ann Cooper MD via email as follows.
Me: Your observation that many survive direct lightning strike may be due to the high frequency components of the lightning current flowing only along the skin surface of the victims.
Mary Ann: Yes: flashover as it is known.
Me:The high frequency components of lightning travel along the skin of the victim in the form of a flash over as you stated. However, the low frequency components enter the body and exit to the ground via the lower limbs of the victim. In that case, the duration of lightning may decide the outcome-life or death in my opinion. Studies on the effect of magnitude and duration of LV current through a human body are well known. Any such study on lightning?
Mary Ann: I will refer you to Chris Andrews, MD, PhD, who modelled lightning effects as part of his dissertation, but who also sits on the IEC working committee for this and has written some materials for them recently about effects on the human body.He is an Australian who was in Chicago for the meeting two weeks ago and stayed with us a few days, as usual for his trips across the US.
It may also have to do with when the strike hits during the cardiac cycle as parts of it are more vulnerable to causing ventricular fibrillation, a nonfunctional rhythm where each muscle fiber is beating at a different frequency than the others, resulting in no flow, which deteriorates to asystole (flatline, no activity) and death.
Me: As you noted, lightning may induce ventricular fibrillation in its victim. However, a defibrillator uses a current pulse (similar to lightning) of several thousand volts to revive a fibrillating heart patient! Again I think it has to do with the duration of passage of current through the victim's body that decides the outcome-life or death for the person involved.
Mary Ann: Perhaps it would be better for you to review the cardiac electrophysiology literature instead of speculating.
The discussion stands there as on today.
http://www.foxnews.com/us/2017/08/25/hiker-hit-by-lightning-woke-up-with-blood-everywhere.html
In this regard I had a discussion with Dr. Mary Ann Cooper MD via email as follows.
Me: Your observation that many survive direct lightning strike may be due to the high frequency components of the lightning current flowing only along the skin surface of the victims.
Mary Ann: Yes: flashover as it is known.
Me:The high frequency components of lightning travel along the skin of the victim in the form of a flash over as you stated. However, the low frequency components enter the body and exit to the ground via the lower limbs of the victim. In that case, the duration of lightning may decide the outcome-life or death in my opinion. Studies on the effect of magnitude and duration of LV current through a human body are well known. Any such study on lightning?
Mary Ann: I will refer you to Chris Andrews, MD, PhD, who modelled lightning effects as part of his dissertation, but who also sits on the IEC working committee for this and has written some materials for them recently about effects on the human body.He is an Australian who was in Chicago for the meeting two weeks ago and stayed with us a few days, as usual for his trips across the US.
It may also have to do with when the strike hits during the cardiac cycle as parts of it are more vulnerable to causing ventricular fibrillation, a nonfunctional rhythm where each muscle fiber is beating at a different frequency than the others, resulting in no flow, which deteriorates to asystole (flatline, no activity) and death.
Me: As you noted, lightning may induce ventricular fibrillation in its victim. However, a defibrillator uses a current pulse (similar to lightning) of several thousand volts to revive a fibrillating heart patient! Again I think it has to do with the duration of passage of current through the victim's body that decides the outcome-life or death for the person involved.
Mary Ann: Perhaps it would be better for you to review the cardiac electrophysiology literature instead of speculating.
The discussion stands there as on today.
