Biomedical subjects

D Kallieris

Publications and source records attributed to D Kallieris.

At least 37 records · Page 2Linked to original sources

PubMed1990

[Injuries of the occipital condyles in fatal traffic accidents].

Among 600 deaths of traffic accidents we found injuries of the occipital condyles in 10 cyclists, 12 car drivers and 3 pedestrians. In most cases the collision speed ranged from 70 to 100 km/h. In 18 cases of direct head impact the more severe injury was on the opposite side, in 4 cases of indirect side impact (whiplash injury) on the same side. Most types of fractures were 12 horizontal disconnections and 4 fractures of the inner edges. In 9 cases the condyle fractures were on one side, in 16 cases on both sides.

Accidents, Traffic↗

PubMed1989

[Quasi-static and dynamic bending stress of the pediatric femur for producing a femoral fracture].

At the Institute of Forensic Medicine of the University of Heidelberg, in the years 1986-1988 thigh loading tests were conducted in order to produce fractures in a total of 28 cadavers of babies and children who had died at ages ranging from 1 day to 6 years. In 18 tests a universal strength testing machine was used and each thigh was loaded quasi-statically from the outside with a blunt edge applied to the middle of the femur, bending it to the point of fracture. The loading velocity amounted 50 mm/min with a defined support distance. The breakage load amounted to 470 N in a 6-day-old baby and increased about evenly up to 2920 N in a 6-year-old child; however, in a newborn 2720 N was needed and in a 15-month-old child, 5700 N. The total deformation way ranged from 16 to 60 mm. The main types of fracture that occurred were: complete and incomplete transverse fractures, oblique fractures, Messerer fractures, and spongiosa fractures. Ten children ranging in age from 2 months up to 27 months were submitted to dynamical thigh loading by means of a failing weight impactor and a horizontal impactor. Only in one case did a transverse fracture occur, when the lateral thigh impacted on an edge at a falling height of 70-93 cm. The forces set up amounted to 320-600 N with the falling weight impactor and to 2370 N with the horizontal impactor. These results suggest that fracture of the femur does not occur if a baby or small child falls from a changing table or from an adult's arm.

Biomechanical Phenomena↗

PubMed1989

[Stress and kinematic analysis of the head and neck in frontal collision. A comparison of voluntary probands and postmortem human test cadavers].

Investigations comparing dynamics and kinematics in volunteers and postmortem human subjects (PMHS) under the same collision conditions are rare, although such results are of elementary importance in order to estimate the suitability of PMHS as injury indicators in crash tests. Under this aspect, a report on 12 experimental frontal collisions has been made where PMHS were loaded and restrained by a 80 mm broad double shoulder lap-step belt. The impact velocity amounted 60 km/h, the mean vehicle decelerations were at 11 g and 15 g. In the Naval Biodynamics Laboratory in New Orleans, the comparing collective of 9 volunteers in the age range of 18 to 22 years has been investigated by a mean deceleration of 11 g at otherwise comparable conditions. Optical targets have been fixed at the 1st thoracic vertebra, the occiput and the top of the head in the PMHS, the collision phase has been documented by a laterally to the sled mounted high-speed camera with a frame rate of 1000 p/s. The accelerations have been measured tri-axial at the top of the head, at the clivus and the 1st thoracic vertebra. For the simulation of the muscle tonus of the volunteers, formaldehyde has been injected into the neck muscles. In the PMHS as well as in the volunteers no thoracic- or abdominal injuries occurred during the above mentioned loads. However, the spinal column of the PMHS remained uninjured only in 3 cases, in 7 cases hemorrhages in the intervertebral disc, lacerations of the ligamentum flavum or hemorrhages in the vertebral joints were observed.

Acceleration↗

PubMed1988