DE102017121482B4 - Dummy for accident research and forensics - Google Patents

Abstract

Dummy (100) for accident research and forensics, with an artificial skeleton (200) which is formed from a large number of bone elements connected to one another, characterized in that at least the forearm and upper arm bone elements (221 , 223) and the lower leg and femur elements (271, 273) are each formed from a bone substitute substance which comprises an epoxy resin mixed with at least 20% metal powder, and each of at least one tissue element (92, .. 98) made of silicone and/or are connected to such a fabric element (92, .. 98), and- that the bone elements (221, 223, 271, 273) are connected via traction cables and/or straps, which extend over the full length of an arm or a leg along the exterior of the bone elements and/or through internal voids therein and/or through voids within the tissue elements (92, .. 98) extend.

Description

The invention relates to a dummy for accident research and forensics, having the features of the preamble of claim 1.

Such a dummy is a test dummy that is modeled as realistically as possible on a human body (“biofidel”) and is used in particular for trauma research, for example for researching and simulating traffic accidents involving pedestrians.

In the automotive industry, when carrying out standardized crash tests, crash test dummies are placed in vehicles in order to be able to measure the impact of an accident on the occupants. These dummies, such as the "Hybrid III" type, which is prescribed for crash tests and is therefore widespread, are equipped with extensive sensors in order to be able to measure acceleration and deceleration. However, they do not come close to the human body either in terms of their external dimensions or in terms of mass and mass distribution. A skeleton and tissue structure is completely missing, so that in view of the significantly different properties of the body surface and the internal structure of the dummy, realistic tests are not possible if such a dummy were used for tests outside of a vehicle.

There is also a need for test dummies in forensics, e.g. B. to simulate falls of people for crime investigations and to determine whether an external influence was likely or not. Simple puppets consisting of connected bags or sacks filled with sand or water to increase the weight do not exhibit realistic falling, flying and falling behavior.

Through the lecture by Dr. M. WEYDE: "Construction and testing of a pedestrian dummy for realistic vehicle damage in experimental simulations of car vs. pedestrian collisions", held at TRANSCOM 2013, Zilina (SK) on June 26, 2013, a human-like dummy is known that has a skeletal-like structure surrounded by silicone elements that serve as tissue elements. Due to a size and mass distribution that is already very similar to the human body, this dummy can be used to achieve comparable behavior when the dummy crashes into a vehicle and is thrown off the vehicle. However, it has been shown that the injury patterns observed on the known dummies do not correlate with the injury patterns of the human body in a comparable real accident situation. Such test dummies are also referred to as "biofidele" dummies because of the desired strong imitation of the natural model.

The DE 40 12 691 A1 shows a dummy with an artificial skeleton formed from a plurality of interconnected bone elements, wherein at least one bone element is formed from a bone substitute substance comprising an epoxy resin. The bone elements are connected to one another via one-dimensional technical bearing connections. There are no elements for simulating tendons, ligaments, and muscle and fat tissue.

The US2012/0265321 and U.S. 6,471,519 B1 each describe an artificial bone made from a bone substitute material which consists of an epoxy resin mixed with metal oxide particles. The bone is said to be used for medical training. There is no connection with a dummy. Also, no other elements for simulating body parts are specified.

The object of the present invention is therefore to approximate the movement behavior of the dummy even more closely to the human body during the test and, in particular, to approximate the injury patterns occurring on the skeleton to the human body to such an extent that it can be checked whether an accident simulated in the test with the assumed real accident occurrence agrees or that an expected injury pattern is predictable.

This object is solved by a dummy having the features of claim 1.

Essential to the invention is the optimized material selection and composition for at least some of the bone elements that are assembled to form a skeleton replica for the dummy.

With regard to the bone elements, a bone substitute material was selected according to the invention, which consists of a hardenable epoxy resin mixture that contains metal powder as an additional component, which is present homogeneously and finely distributed in the resin matrix. The metal powder is in particular aluminum powder with a particle size of less than or equal to 100 μm.

The epoxy resin-metal powder mixture can be poured into a mold where it hardens duroplastically, so that more complex shapes are possible than in the case of the dummies known in the prior art with bone elements made of wood. In contrast to wood, the cast epoxy resin-metal powder mixture results in a bone element with isotropic mechanical properties properties, ie the strength values are not dependent on the direction of force; unlike wood, where the properties in the direction of the grain differ significantly from those across it.

• Zum einen wird die Harzstruktur durch die eingebetteten Metallpartikel etwas künstlich versprödet, also die Zug- und Biegefestigkeit herabgesetzt. Knochenelemente aus Epoxidharz alleine wären bei einem dem menschlichen Vorbild angepassten Querschnitt der Knochenelemente zu stark belastbar, so dass bei Unfallversuchen keine realitätsnahen Verletzungen am Skelettnachbaus des Dummys entstehen würden. In diesem Zusammenhang muss auch berücksichtigt werden, dass das menschliche Knochengewebe nicht homogen ist, sondern harte Außenschichten, der sogenannten Substantia corticalis und schwammartige, mikroporöse Innenschichten (Substantia spongiosa) sowie in vielen Knochen röhrenförmige Hohlräume besitzt.

By mixing in metal powder, two essential effects are achieved:

• On the one hand, the resin structure is somewhat artificially brittle due to the embedded metal particles, i.e. the tensile and flexural strength is reduced. Bone elements made of epoxy resin alone would be too strong with a cross section of the bone elements adapted to the human model, so that no realistic injuries would occur on the skeleton replica of the dummy during accident tests. In this context, it must also be considered that human bone tissue is not homogeneous, but has hard outer layers, the so-called substantia corticalis, and spongy, microporous inner layers (substantia spongiosa), as well as tubular cavities in many bones.

Surprisingly, the mechanical properties are favorably influenced by the inventive mixture of epoxy resin with metal powder, in particular aluminum powder, in such a way that the dimensioning of the individual components for the artificial skeleton can be made very similar to the respective human model and can therefore also be applied to the limbs, which, in addition to the bone elements, also include ligaments and tissue elements, result in similar masses and centers of gravity. The ductility of the bone elements simulated according to the invention is thus very similar to human bones with similar geometric dimensions, and accordingly a very comparable fracture pattern is also shown on the dummy skeleton after a test. The course of fractures, including the detachment of bone splinters, is very similar to the effects of dreams on human bones. Density and mechanical resilience are also similar to the human model for comparable cross-sections.

On the other hand, an effect of the mixed metal powder that is also very important for the invention is that the dummy according to the invention can be examined in a computer tomograph or a classic X-ray device, with the additional special selection of a silicone material for the tissue elements according to the invention leading to the fact that they can be examined without any problems can be radiographed and a clear image of the bone elements hidden underneath becomes visible through the imaging process. The mixing in of powder evenly distributed in the resin matrix, in particular aluminum powder, in a volume mixing ratio of about 2:1 means that the X-ray radiation is not completely absorbed by the bone element designed according to the invention, so that areas that are not completely bright arise in the X-ray image, such as with solid metal, but that shades of gray also become visible. Even the fractures that occurred on the dummy's skeleton during the accident tests can be easily identified with the medical imaging methods.

The invention thus created a dummy that is particularly suitable for X-ray examinations and can be examined in the computer tomograph after an accident test has been carried out without any prior disassembly. The course of the fracture and the position of broken bone elements come very close to the human model and, when reproducing accidents, allow a statement to be made as to whether the parameters assumed for the test were realistic and actually depict the real accident.

For a realistic traumatization of the dummy, in addition to the selection of the material for the bone elements, the material selection for the tissue elements is also important, which simulates human tissue and completely or partially surrounds or attaches to the bone elements. Because these should be elastically deformable to the same extent as the human body, but on the other hand also plastically deformable, because human tissue is viscoelastic, i.e. only shows a really elastic behavior to a very limited extent in the sense that a restoring Adjusts spring force, and after an elongation that exceeds about 2%, a plastic deformation occurs.

For this purpose, according to the invention, silicone compounds of the RTV type are used for the fabric elements, ie 2-component mixtures which crosslink at room temperature and vulcanize at room temperature.

The fabric elements preferably consist of a silicone compound whose hardness after a setting time of 24 hours and at a test temperature of 23° C. is 55 ± 4 Sh00 according to the “Shore 00” scale suitable for very soft elastomers.

It is also important that the tissue elements present in the dummy according to the invention have mechanical properties that are independent of the storage time and that no post-hardening or embrittlement processes take place during the intended storage and service life.

The connections used are so elastic that they can also be used to produce and demould pronounced undercuts. Therefore, similar silicone compounds as for the production of the tissue elements are preferably also produced for the production of the molds into which the liquid epoxy resin-metal powder mixture is poured to form the bone elements. Depending on whether undercuts have to be removed from the mold or not, more or less hard silicone rubber is used for mold construction. The hardness of the casting molds is preferably between 4 Shore-A and 25 Shore-A.

A large number of fabric elements are combined in a fabric element set. The subdivided fabric elements make assembly much easier. All fabric elements are optimized for easy plug-in assembly in order to be able to easily connect them to the associated components of the skeleton.

By exchanging the set of tissue elements, different statures or genders can be represented with the same skeleton size.

The shoulder fabric element extends into the chest area and is preferably divided into a rear and a front element in order to facilitate assembly on the one hand and to be able to adapt to the female anatomy on the other by exchanging the front partial element.

The collarbone elements remain free between the two partial elements of the shoulder fabric element, ie they are not covered by the fabric elements, but only later by the neoprene suit serving as a skin replacement. This means that the clavicle elements are heavily exposed, as in humans.

Preferably, the bone elements that simulate the outer extremities of humans on the dummy, i.e. upper and lower legs as well as upper and lower arms, are each designed in such a way that the bone element has an elongated stem area that can be significantly widened at one end in order to example to form a joint half. At the other end, on the other hand, a fixed widening is preferably provided and the bone element ends with a constant or with a tapering cross section.

The open, preferably undercut-free end of the bone element is inserted into a socket of another skeletal component such as a condyle element and connected thereto, or it is butt-screwed to another bone element. This results in the particular advantage that when the dummy is assembled, the long stem of the club-like bone element can be inserted through a narrow cavity in an associated tissue element. Hardly any play is therefore required between the cavity boundary and the bone element. The tissue element thus lies tightly against the section of the bone component.

There are also advantages in production, because the parting plane of a casting tool can be placed at the joint for the most realistic possible formation of the connected half of the joint, in order to enable complex shaping there without having to take into account the demoulding of the stem area, which is free of undercuts must be taken.

The free end of the stem on the bone element is then preferably pushed into a receptacle on another joint element, resulting in the typical bone shape of the large bones on the extremities with the two thickened ends. The connection between the stem of the bone element and the joint element is preferably made by means of pin-shaped elements arranged crosswise. In order not to impede the above-described imaging by X-rays, provision is made in particular to use non-metallic pins.

Alternatively, although radial projections may be present; in this case, however, an associated receiving socket on the counterpart has slot-shaped recesses, so that the handle area can be pushed into the receiving socket.

Provision is also made for the extremities to have pull ropes or straps run along the outside and over the entire length of the arm or leg. These extend along the bone elements. Here, the invention provides two groups of ropes or straps that are used together or alternatively. Both groups each extend closely along the bone elements or through internal cavities therein and/or are guided with them through cavities within the tissue elements.

A first set of ropes or webbing is used to secure limbs that may have been torn off during the attempted accident. It is a security measure for the experimental setup or for any spectators in the vicinity and prevents a total loss for the torn-off individual parts. These safety devices should not impede the movement of the skeleton, insofar as they are still normal corresponds to human movement patterns. Therefore they stretch very loosely from the shoulder over the arm to the hand or from the pelvic bone element and/or the spinal column unit over the leg to the foot. These straps are only tightened and thus become effective after parts of the dummy have been detached during the course of the accident test.

The other group of ropes or straps simulates the tendons and ligaments present in the human body and accordingly limits the mobility of individual skeletal parts to natural movement possibilities. These straps are performed tightly and z. B. held with clamps directly on the outside of the bone elements.

• 1, 2 jeweils einen Dummy in Ansicht von hinten;
• 3 einen Dummy in Seitenansicht;
• 4 ein Unterarmknochenelement in perspektivischer Ansicht; und
• 5 die Montage eines Unterarms in schematischer, seitlicher Ansicht.

An exemplary embodiment of a dummy is explained below with reference to the drawings. The figures show in detail:

• 1 , 2 one dummy in rear view;
• 3 a dummy in side view;
• 4 a forearm bone element in perspective view; and
• 5 the assembly of a forearm in a schematic side view.

1 10 shows a rear view of a dummy 100 . This is almost complete, ie an internal supporting skeletal structure is assembled and fabric elements made of soft silicone are placed on top. The only thing missing is a cover that serves to simulate human skin tissue. For this purpose, the in 1 The dummy shown is dressed in a neoprene suit, which is coated with latex.

• - Füße 1 und Hände 3 sind jeweils für sich als vollständige Baugruppe ausgebildet, aber sind in sich nicht weiter untergliedert, d. h. Hand- und Fußknochen werden nicht simuliert, da dies aufgrund der Anzahl kleinster Knochenelemente sehr aufwändig wäre, jedoch für die Verkehrsunfallforschung zunächst ohne Bedeutung ist.
• - Der Kopf 2 wird durch eine Innenfüllung aus Silikon, eine Schädelnachbildung aus der Knochenersatzsubstanz und eine Kopfaußenhaut aus Silikon gebildet.
• - Der Fuß 1 ist mit einem Unterschenkel 21 verbunden, der über ein Kniegelenk 22 mit einem Oberschenkel 23 verbunden ist. Unterschenkel 20, Kniegelenk 22 sowie Oberschenkel 23 sind Teil einer Beingruppe 20, die wie beim menschlichen Vorbild funktional zusammenwirkt und bei dem Dummy 100 als Baugruppe vormontiert werden kann.
• - Die beiden Beingruppen 20 sind mit einer Beckengruppe 30 verbunden. Diese ist über eine innenliegende Wirbelsäulengruppe 50, von der nur ein nach außen ragender Haken für die Aufhängung des Dummys 100 bei Pendelversuchen sichtbar ist, mit einer Rumpfgruppe 40 verbunden.
• - Außerdem ist eine Schultergruppe 60 mit der Wirbelsäulengruppe 50 verbunden.
• - Beidseits der Schultergruppe 60 schließen sich Armgruppen 70 an, die jeweils vormontierbar sind und die jeweils einen Oberarm 73, ein Ellbogengelenk 72 und einen Unterarm 71 enthalten. Hieran ist die Hand 3 angesetzt.

1 serves to name the most important assemblies:

• - Feet 1 and hands 3 are each designed as a complete assembly, but are not further subdivided, ie hand and foot bones are not simulated, since this would be very complex due to the number of tiny bone elements, but initially of no importance for traffic accident research is.
• - The head 2 is formed by an inner filling made of silicone, a skull replica made of the bone replacement substance and an outer skin of the head made of silicone.
• The foot 1 is connected to a lower leg 21 which is connected to a thigh 23 via a knee joint 22 . Lower leg 20, knee joint 22 and thigh 23 are part of a leg group 20, which interacts functionally as in the human model and can be preassembled in the dummy 100 as an assembly.
• - The two leg groups 20 are connected to a pelvic group 30. This is connected to a torso group 40 via an internal spinal column group 50, from which only a hook projecting outwards for hanging up the dummy 100 during pendulum tests is visible.
• - In addition, a shoulder group 60 is connected to the spine group 50.
• - Arm groups 70 connect on both sides of the shoulder group 60, which can each be preassembled and each contain an upper arm 73, an elbow joint 72 and a forearm 71. The hand 3 is attached to this.

The above assemblies each consist of an internal skeletal assembly with bone and cartilage replicas and ligaments, and silicone soft tissue elements surrounding the bony elements and simulating human muscle and adipose tissue.

2 shows the same dummy 100 in the same view as 1 , wherein the individual tissue elements of a tissue element set 90 which surround the internal skeletal structure of the dummy 100 are referred to herein.

In the illustrated preferred embodiment of a fabric element set 90 for the dummy 100 only a single lower leg fabric element 91 is provided on the lower leg 21 . This has a tubular inner cavity. At the same time, the bone elements designed according to the invention are designed with at least one stem area that is not undercut, so that not only is it easier to manufacture by casting the silicone compound in a mold and then removing it from the mold, but quick assembly is also possible because the stem area passes through the cavity can be pushed through in the fabric element and secured from the opposite side.

Due to the great length of the thigh 23, among other things, two fabric elements 93.1, 93.2 are provided there, which can be assembled individually. The upper thigh fabric element 93.2 connects with its upper end at 45° to a pelvic fabric element 94.1. The leg group 20 can be rotated in the hip joint due to the sloping parting plane. In the area of the pelvis, next to the right pelvic fabric element 94.1, there is a second, left pelvic fabric element 94.2 intended. Due to the complex internal structure of the pelvis, the pelvic fabric elements 94.1, 94.2 are pushed on to the side and then connected to one another via a circumferentially tensioned band. For this purpose, the two fabric elements 94.1, 94.2 have a constriction 94.3 in the upper area, into which a tension belt or an adhesive tape can be inserted without something protruding beyond the outer contour of the dummy. Such a circumferential groove is also provided in several other fabric elements of the fabric element set 90 . Should e.g. B. Difficulties arise during assembly using the plug-in method, particularly in the fuselage area, so the individual parts of the fabric element set 90, which are made of very soft silicone, can be cut open on one side with a knife up to the inner cavity. The cut fabric element is so easily deformed that it can be unfolded and wrapped around the internal skeletal structure. The cut line is then held together using the mentioned straps or adhesive strips until the dummy 100 is covered with the neoprene suit and the latex layer.

Above the two pelvic fabric elements 94.1, 94.2 is an outer torso fabric element 95. In addition, a non-visible inner fuselage fabric element is provided. On the one hand, there are production-related reasons for the division into two parts, since a single compact fuselage fabric element would result in excessive masses and wall thicknesses, and it would therefore take too long for the two-component silicone to fully harden. Second, the inner torso fabric element simulates the organs within the thorax and the outer torso fabric element 95 simulates the layers of muscle and fat above the ribs.

Above this is a shoulder fabric element 96 which also has a neck extension 96.1 on which the head 2 is mounted. The shoulder fabric element 96 does not extend laterally across the width of the torso fabric element 95, but even lags somewhat behind it. An upper upper arm fabric element 97.1 is provided on the upper arm 73, which also does not completely enclose the area of the shoulder. The gap formed between the shoulder fabric element 96 and the upper upper arm fabric element 97.1 serves to obtain a very good mobility of the arms 70 and not to impede it by the fabric elements. As on the thigh, the fabric elements on the upper arm 73 are divided into two. In addition to the upper arm fabric element 97.1 already mentioned, which partially covers the shoulder group 60, there is a lower upper arm fabric element 97.2, which accommodates the upper arm bone element. Gaps remain at the transition between the lower upper arm fabric element 97.2 and a lower arm fabric element 98 in order to maintain the mobility of the elbow joint 72.

3 shows the tissue element set 90 or the dummy 100 in a lateral view from the right. The free spaces between a lower leg fabric element 91 and a lower thigh fabric element 93.1, which leave the knee joint 22 free, are particularly evident here. A band 322 that runs laterally over the knee joint 22 can also be seen here. The upper thigh fabric element 93.2 adjoins without a gap. There are also no gaps between the pelvic fabric element 94.1, the outer torso fabric element 95 and the shoulder fabric element 96, resulting in the effect of a uniform upper body. The upper upper arm fabric element 97.1 and the lower upper arm fabric element 97.2 also complement each other without a gap. The side view of 3 again clearly shows the recesses in the lower upper arm fabric element 97.2 and in the lower arm fabric element 98 in the area of the elbow joint 72.

4 shows a forearm bone element 271, which is described here as an example for the bone elements of the extremities provided in the dummy 100 according to the invention. Like all other bone elements of the dummy 100, the forearm bone element 271 is designed in such a way that on the one hand it represents an approximation to the human model, but on the other hand it is also a technical construction element that has been optimized and detached from the model and is by no means just a cast of a natural one Bone should represent with artificial materials. Rather, the construction element in the overall context of the skeleton should enable 200 strengths, mass points and mobility that are similar to the human model.

Two cylindrical stem sections 271.1, 271.2 simulate fibula and tibia bones and are connected to each other via a spreading head section 271.6. Both handle sections 271.1, 271.2 contain bores 271.3, 271.4, which are provided via inserted dowels, threaded sleeves or in some other way for receiving screws, so that a screw connection with a wrist element is possible. A joint mount 271.5 is provided for receiving a cylindrical axis on the elbow joint 72.

5 shows, representative of the assembly of the other extremities, the possible plug-in assembly of a forearm 71 according to the invention Forearm bone element 271 is pushed into an inner channel 98.1 of forearm tissue element 98 with its stem sections 271.1, 271.2. A wrist element 276 is pushed into the channel 98.1 from the other side ( 5 ) leaving enough space to carry out the in 5 tapes not shown remains. The forearm bone element 271 is completed and fixed within the forearm tissue element 98 by screwing the wrist element 276 to the stem sections 271.1, 271.2. The respective bone elements can be quickly and easily connected to the associated tissue elements using the plug-in assembly illustrated. Dismantling is just as easy, so that after a test has been carried out, an exact analysis of the damage that has occurred to the bone elements can be carried out and damaged parts can be easily replaced when the dummy is subsequently rebuilt.

Claims (9)

Dummy (100) for accident research and forensics, with an artificial skeleton (200) which is formed from a large number of interconnected bone elements, characterized in that at least the forearm and upper arm bone elements (221 , 223) and the lower leg and femur elements (271, 273) are each formed from a bone substitute substance which comprises an epoxy resin mixed with at least 20% metal powder, and each of at least one tissue element (92, .. 98) made of silicone and/or are connected to such a fabric element (92, .. 98), and - that the bone elements (221, 223, 271, 273) are connected via traction cables and/or straps, which extend over the full length of an arm or a leg along the outside of the bone elements and/or through internal voids therein and/or through voids within the tissue elements ( 92, .. 98). Dummy (100) after claim 1 , characterized in that the metal powder has an average particle diameter of less than 100 µm. Dummy (100) after claim 1 or 2 , characterized in that the metal powder is aluminum powder. Dummy (100) after one of the Claims 1 until 3 , characterized in that the bone replacement substance contains epoxy resin and metal powder in a volume ratio of 2:1. Dummy (100) after one of the Claims 1 until 4 , characterized in that at least one fabric element (92, .. 98) of a fabric element set (90) for the dummy is formed from a two-component silicone which crosslinks at room temperature and which, after vulcanization for at least 24 hours and at a test temperature of 23°C, has a hardness of 55 ± 5 Shore-00. Dummy (100) after one of the Claims 1 until 5 , characterized in that at least one fabric element (92, .. 98) of a fabric element set (90) for the dummy is formed from a two-component silicone which crosslinks at room temperature and which, after vulcanization for at least 24 hours and at a test temperature of 23°C, has a hardness of 2 to 10 Shore-A. Dummy (100) according to one of the preceding claims, characterized in that the bone elements (271, 273, 221, 223) of the lower and/or upper extremities each have at least one stem section (223.1, 271.1, 271.2) which is only attached to one end has a thickened articulation piece formed on it and its other end is detachably inserted into a receiving socket (224.1, 274.1) on a further bone element (224, 274) and/or is connected to a further bone element (276) via its front end. Dummy (100) according to one of the preceding claims, characterized in that a first group of ropes or straps is provided for securing, which loosely runs from the shoulder over the arm to the hand or from the pelvic bone element and/or the spinal column unit over the leg extend to the foot. Dummy (100) according to one of the preceding claims, characterized in that a second group of ropes or straps is provided for simulating tendons and ligaments, which are taut along the bone elements (221, 223, 271, 273) of the arm or leg are led.

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