Featured Research

from universities, journals, and other organizations

Vitreous Humor In The Eye Helps To Establish Time Of Death

Date:
December 6, 2008
Source:
Plataforma SINC
Summary:
Scientists have proposed a new method to estimate the approximate time of death. This is based on the analysis of several substances from the vitreous humor of the eye of cadavers, according to an article published in the journal Statistics in Medicine. Using this system, scientists have developed a piece of software that makes it possible to establish precisely the post mortem interval (PMI), information that will make the work of the police and the courts of justice easier.

A team of researchers from the University of Santiago de Compostela has proposed a new method to estimate the approximate time of death. This is based on the analysis of several substances from the vitreous humour of the eye of cadavers, according to an article published in the journal Statistics in Medicine.

Related Articles


Using this system, scientists have developed a piece of software that makes it possible to establish precisely the post mortem interval (PMI), information that will make the work of the police and the courts of justice easier.

To apply this technique the researchers analyse initially potassium, urea and hypoxantine (a DNA metabolite) concentrations present in the vitreous humour of the eye of the human cadaver, and introduce these figures into a computer programme. The software that has been invented by these Galician scientists uses this information and is capable of establishing the time at which death occurred.

“The equations we have developed now make it possible for us to estimate the PMI more precisely than before, and provide a useful and accessible tool to forensic pathologists that is easy to use” José Ignacio Munoz Barús, one of the authors of the study, explains to SINC, and who is also a specialist doctor from the Institute of Legal Medicine at the University of Santiago de Compostela.

The traditional techniques for estimating the PMI are based on the study of parameters such as the rectal temperature of the cadaver or one of the organs, such as the liver, in rigor mortis, or post mortem lividity examination. These methods are complemented by biochemical analyses of the body fluids. One of these is the vitreous humour, the gelatinous liquid that is found behind the crystalline lens of the eye.

Muñoz Barús points out that the study, published recently in Statistics in Medicine, suggests mathematical models that are “more flexible, useful and efficient” than those that have been applied until now. The doctor describes some of the previous techniques as “not very reproducible, not very precise and untested in the field”, such as the deterioration of DNA, immunoreaction or the traditional techniques based on the biochemistry of the vitreous humour.

In this last case the researcher specifies that previous studies used a “linear regression mathematical model” which assumes that the concentrations of potassium, hypoxantine and urea increase in a linear way that is more or less constant throughout the post mortem interval. However, the new analyses suggest that those premises are not valid and that the statistical models known as generalized additive models (GAM) or the support vector machine (SVM) models are more flexible and much more useful, since they avoid the assumption of linearity”.

The precision and usefulness of these two models have been confirmed by chemical analysis in more than 200 vitreous humour samples. The doctor and the two mathematicians who have performed the study have verified that the SVM method offers more precise data, although the GAM method is more easy to assimilate to the linear model and understand graphically and numerically, “ for which reason both complement each other”.

The three scientists have incorporated all this information into the development of a free computer package (based on code “R”) which makes it possible to establish the PMI using four predictive variables: concentrations of potassium, hypoxantine and urea, and cause of death. In addition, the software makes it possible to show the results graphically. “In this way the estimation of the time of death and expert examination are made easier when attending the courts of justice”, Munoz Barús points out to SINC

“The precise determination of the exact time of death has been the subject of various studies going back to the 19th century, since this information is of paramount importance in the field of legal medicine, owing to its repercussions on crime and civil society. This new method offers an important contribution to this field”, the researcher concludes.


Story Source:

The above story is based on materials provided by Plataforma SINC. Note: Materials may be edited for content and length.


Cite This Page:

Plataforma SINC. "Vitreous Humor In The Eye Helps To Establish Time Of Death." ScienceDaily. ScienceDaily, 6 December 2008. <www.sciencedaily.com/releases/2008/12/081204133857.htm>.
Plataforma SINC. (2008, December 6). Vitreous Humor In The Eye Helps To Establish Time Of Death. ScienceDaily. Retrieved November 27, 2014 from www.sciencedaily.com/releases/2008/12/081204133857.htm
Plataforma SINC. "Vitreous Humor In The Eye Helps To Establish Time Of Death." ScienceDaily. www.sciencedaily.com/releases/2008/12/081204133857.htm (accessed November 27, 2014).

Share This


More From ScienceDaily



More Computers & Math News

Thursday, November 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

EU Pushes Google For Worldwide Right To Be Forgotten

EU Pushes Google For Worldwide Right To Be Forgotten

Newsy (Nov. 27, 2014) — Privacy regulators recommend Google expand its requested removals to apply to all its web domains. Video provided by Newsy
Powered by NewsLook.com
Predictions Of Tablets' Demise Sound Familiar

Predictions Of Tablets' Demise Sound Familiar

Newsy (Nov. 26, 2014) — The tablet's days are numbered, at least according to a recent IDC report. The market-research firm paints a grim outlook for tablets. Video provided by Newsy
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) — Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. Video provided by Newsy
Powered by NewsLook.com
FCC Forces T-Mobile To Alert Customers Of Data Throttling

FCC Forces T-Mobile To Alert Customers Of Data Throttling

Newsy (Nov. 25, 2014) — T-Mobile and the FCC have reached an agreement requiring the company to alert customers when it throttles their data speeds. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins