Biomedical subjects

P Schyma

Publications and source records attributed to P Schyma.

5 recordsLinked to original sources

PubMed1997

[Gunshot wounds--homicide, suicide or accident?].

Gunshot residues on the hand are an important evidence of shooting. Different methods for sampling gunshot residues from the hands are presented and critically analyzed. The topographic methods-adhesive film and polyvinyl alcohol technique (PVAL)-have serious advantages over the cumulative methods like tape-lift or cotton swab. Case examples demonstrate the limited interpretation of results with cumulative methods. Negative results of tape-lifts or cotton swabs can also be explained by the presence of blood or dirt, positive results however don't prove shooting. The sampling method with the highest gain of gunshot residues is the PVAL technique which takes about 2 hours of sampling traces. Therefore PVAL is mostly applied post mortem. PVAL shows the distribution of gunshot residues also on bloody hands and is a powerful instrument for the reconstruction of the firing position. But the final differentiation between homicide, suicide or accident is not only based on gunshot residues, but requires a complex analysis of all findings in a case (scene, blood traces, autopsy, shot range).

Accidents↗

PubMed1996

[Reliability of back-calculation of blood alcohol concentration to the time of infraction].

In order to be able to give an accurate legal judgement of a drink driving offense, the BAC at the time of the offense has to be determined. The calculation which may be necessary is based on the time of blood sampling and on the time of the offense. The authors examined records of 854 blood samples taken in the years 1979 and 1989 with regards to the times recorded. Blood sampling recorded on the hour or on the half hour could be found four times more frequently than would have been statistically expected. Blood sampling recorded to the nearest five or ten minutes were documented three times as often as those ending on the exact minute. Times of the offense were recorded at least ten times as often to the nearest five minutes. The rounding up of times could cause discrepancies of more than 0.01% when calculating the BAC at the time of offense.

Accidents, Traffic↗

PubMedDate not supplied

[Video documentation in forensic practice].

The authors report in part 1 about their experiences with the Canon Ex1 Hi camcorder and the possibilities of documentation with the modern video technique. Application examples in legal medicine and criminalistics are described autopsy, scene, reconstruction of crimes etc. The online video documentation of microscopic sessions makes the discussion of findings easier. The use of video films for instruction produces a good resonance. The use of the video documentation can be extended by digitizing (Part 2). Two frame grabbers are presented, with which we obtained good results in digitizing of images captured from video. The best quality of images is achieved by online use of an image analysis chain. Corel 5.0 and PicEd Cora 4.0 allow complete image processings and analysis. The digital image processing influences the objectivity of the documentation. The applicabilities of image libraries are discussed.

Equipment Design↗

PubMedDate not supplied

[Gunshot into the eye].

A 55-year-old man was found dead sitting at his work-bench. A pistol Parabellum 1908 (9 mm Luger) was disassembled on the work-table. A pack of 9 mm Luger full metal jacket ammunition was opened. The left side of his glasses and the left eye were injured. The autopsy proved the death from air embolism. Radiography of the head revealed metallic fragments along the bullet path. The bullet had lost the jacket and the core was fragmented. Gunshot residues on the hands of the deceased and on the left side of the face indicated that the lethal injury was self inflicted. The function of the pistol "08" explicated that a shot could be fired from the isolated barrel which formed a unit with the bolt. The bullet showed traces of manipulation. In the house there were found other self-made dumdum-bullets. Death could be explained as an accident while cleaning the pistol.

Accidents, Home↗

PubMedDate not supplied

[Possibilities for injuries caused by rubber bullets from the self-defense weapon MR 35 Punch].

Manurhin developed a "non lethal" weapon, the MR 35 Punch, which fires 21 g weighing rubber balls of 35 mm caliber. The black powder cartridges which were used as propellant cause important variations of the projectile's velocity from 120 to 140 m/s. The resulting energies were about 150 to 200 J. The wounding potential was examined by shots on different materials and gelatin. Shots from 2 to 5 m distance caused penetrations of 3 to 8 cm in 10 percent gelatin. Covering the gelatin with skin or thick textiles did not significantly change the penetration. Skin and textiles were penetrated in all experiments. Pieces of flat bone which were embedded in gelatin were fractured by the shots, in part fracture elements were dislocated. The discussion of the wound ballistic results contradict the "non lethal" character of the MR 35 Punch.

Firearms↗