Biomedical subjects

C Tingvall

Publications and source records attributed to C Tingvall.

14 recordsLinked to original sources

PubMed2000

How crash severity in rear impacts influences short- and long-term consequences to the neck.

The main public-health problem concerning WAD are injuries leading to long-term consequences. Yet epidemiological studies mostly concentrate on data based on the injury outcome occurring shortly after the crash. The purpose of this article is to study the influence of crash severity in rear impacts leading to short and long-term consequences to the neck (WAD 1-3), lasting less than or more than 1 year. The influence of change of velocity as well as the car acceleration were investigated by using data from crash pulse recorders (CPR) installed in vehicles, involved in rear impacts. The influence of the car acceleration were also investigated by studying the frequency of occurrence of a tow-bar (hinge) on the struck car. Apart from real-life data, full-scale car-to-car crashes were performed to evaluate the influence of a tow-bar on the struck car. The crash tests showed that a tow-bar may significantly affect the acceleration of the car as well as that of the occupant. According to real-life crashes, a tow-bar on the struck car increased the risk of long-term consequences by 22% but did not affect the risk of short-term consequences. Out of the 28 crash recorder-equipped struck cars involving 38 occupants, 15 sustained no injury where the peak acceleration was 6g or less, 20 sustained short-term consequences where the peak acceleration was 10g or less. Three occupants from two different crashes sustained long-term consequences. The two crashes which resulted in long-term disabling neck injuries had the highest peak acceleration (15 and 13 x g), but not the highest change of velocity.

Acceleration↗

PubMed2000

Neck injuries in frontal impacts: influence of crash pulse characteristics on injury risk.

AIS1 neck injuries are the most frequent disabling injuries among car occupants in road traffic accidents. Although neck injury is mostly regarded as resulting from rear end collisions, almost one third of all neck injuries occur in frontal impacts. The injury mechanisms in both rear-end and frontal impacts are still not known, although different hypotheses exist. Since 1992, approx. 100,000 vehicles on the Swedish market have been equipped with crash recorders to measuring frontal impacts. This paper analyses the influence of different characteristics derived from the acceleration time history on the risk of short- and long-term disability to the neck in frontal impacts. The study includes injury outcomes from 187 restrained front seat occupants in 143 frontal collisions with an overlap exceeding 25%, where the crash pulses have been recorded using crash pulse recorders. The results show that the shape of the crash pulse influences the risk of long-term disability to the neck. The vehicle accelerations in the mid and last third of the crash pulse seem to be important. It is also shown how change of velocity and mean and peak accelerations influence the neck-injury risk. It is suggested that the risk of sustaining an AIS1 neck injury in frontal impacts could be reduced by using more effective pretensioners and more advanced belt-load limiters. These results may also have implications for neck injury mechanisms in rear-end impacts.

Acceleration↗

PubMed1997

Injury severity assessment for car occupants in frontal impacts, using disability scaling.

Injury classification and assessment is one of the most important fields of injury prevention. At present, injury assessment focuses primarily on the risk of fatalities, in spite of the fact that most people who are injured survive the trauma. The net result of a fatality-based approach is that safety and vehicle engineers must make decisions with an incomplete, and sometimes misleading, picture of the traffic safety problem. By applying disability scaling reflecting long-term consequences to injury data, the most significant disabling injuries can be identified. The priorities change with the level of disability used in the scaling. In this study, the risk of permanent medical disability due to different injuries was derived and linked to abbreviated injury scale (AIS) values for 24,087 different injured body regions. This material is based on insurance data. To study how the importance of different bodily injuries changes with different severity assessments in a realistic real-world injury distribution, Swedish insurance industry disability scaling was applied to 3066 cases of belted Volvo drivers involved in frontal collisions. Crash severity was included in the study by using equivalent barrier speed (EBS). When lower levels of disability are included, injuries to the neck and the extremities become the most important, while brain and skull injuries become the most prominent at higher levels of disability. The results presented in this article should be regarded as a contribution to the development of a suitable disability scaling method. The results can also be utilized to further injury research and vehicle design aimed at reducing injuries which have the most important long-term disability consequences.

Accidents, Traffic↗

PubMed1996

Foot-ankle injuries: influence of crash location, seating position and age.

Foot-ankle injuries have increased in relative importance in recent years. As a basis for future countermeasures, an epidemiology study has been undertaken using Swedish accident data from Folksam Insurance. The database consists of 805 foot-ankle injuries out of 57,949 car occupant injuries reported from 1985 to 1991. The influence of crash location, seating position and occupant age is determined for the frequency, incidence and rate of foot-ankle injury in car crashes. Frontal car crashes produce 76% of the AIS 2-3 foot-ankle injuries with 13% in side impacts and 8% in roll-overs. The rate of AIS 2-3 foot-ankle injury is 24.7 per 1000 occupants injured in all crash locations and is similar irrespective of seating positions. Ankle fractures and sprains both occur at an incidence of 3.7 per 1000 injuries, followed by malleolus fractures at 2.7 and midtarsal fractures at 2.4. The foot-ankle injury incidence and rate are significantly greater (p < 0.01) in near oblique-frontal crashes than for 12 o'clock frontals. For drivers in 11 o'clock and front passengers in 12 o'clock, the incidence is 27.8 per 1000 injuries as compared to 17.5 for drivers and front passengers in 12 o'clock crashes. Occupant age is not as significant as seating position and crash location; however, there are higher incidences for rear occupants > or = 60 years old in oblique frontal crashes. Using the new AAAM Impairment Injury Scale (IIS), 48% of the foot-ankle injuries are rated with residual impairment IIS 1-2. The incidence in near-seated occupants is 1.5 times greater in oblique frontal crashes than in frontals. The incidence for IIS 1-2 impairment in near oblique-frontal crashes is 12.8 per 1000 occupant injuries as compared to 8.3 in frontal crashes.

Abbreviated Injury Scale↗

PubMed1995

Crash pulse recorder--validation in full scale crash tests.

Estimation of the accident severity is a fundamental requirement in accident reconstruction and analysis. Accident severity can be measured in many different ways, but in frontal collisions change of velocity, energy equivalent speed or equivalent barrier speed are frequently used parameters. These parameters are most often estimated from vehicle deformation. It is known, however, that the quality of these estimates is limited if compared with these obtained in laboratory test conditions. To be able to achieve almost the same measurements and measurement accuracy in real-life accidents as in the laboratory, where the acceleration time history is measured, an on-board measurement technique is required. This presentation gives results of tests of a low cost device for measuring the crash pulse for a car involved in an accident, concerning systematic and random error. The device, called the Crash Pulse Recorder (CPR), has been tested previously in several sled tests. The CPR is based on measurement of the movement of the mass in a spring mass system in a collision. A brief description of its construction is also included. The CPR is an integral part of a large accident data collection system including interior and exterior deformation measurements and evaluation of injury outcome. This report presents the results of several full-scale crash tests, undertaken to evaluate the accuracy and precision of the CPR in cars in different impact modes. The tests comprised both offset and angled collisions. Most of the tests were car to car collisions, but barrier tests were also performed. The random error of the CPR was found to be 2.2 km/hr for the delta V measurements and 0.6 g for mean acceleration.

Acceleration↗

PubMed1995

Does uvulopalatopharyngoplasty inhibit automobile accidents?

Patients with rhonchopathy, which includes obstructive sleep apnea syndrome (OSAS), who report sleepy spells at the wheel do poorly on simulated monotonous driving tests and have a twofold to threefold increase in traffic accidents. To assess whether drivers with rhonchopathy (heavy snoring, sleep disturbances, and daytime sleepiness) cause fewer automobile accidents after uvulopalatopharyngoplasty (UPPP), the car accident rate for the first 5 years after surgery was compared to the rate of the 5 years immediately before the operation. Data were collected by means of a self-report questionnaire. Fifty-six patients with rhonchopathy were compared to 142 controls without rhonchopathy who had been subjected to nasal surgery. The response rates were 96% and 94%, respectively. The reported habitual sleepiness while driving had disappeared in 87% (P < .001) of drivers who had the problem preoperatively. The accident risk reduction (corrected for mileage) in patients was almost four times greater than the reduction in controls (P < .001) after surgery. The relative rate of patients involved in any single-car accident fell by 77% (P < .05), and the relative rate of single-car accidents fell by 83% (P < .001). It is concluded that drivers with rhonchopathy have an increased risk for car accidents, especially single-car accidents, but that this risk returns to normal after UPPP.

Accidents, Traffic↗

PubMed1994

Photogrammetry for documentation of vehicle deformations--a tool in a system for advanced accident data collection.

Vehicle deformations are important sources for information about the performance of safety systems. Photogrammetry has developed vastly under recent years. In this study modern photogrammetrical methods have been used for vehicle deformation analysis. The study describes the equipment for documentation and recording in the field (semi-metric camera), and a system for photogrammetrical measurements of the images in laboratory environment (personal computer and digitizing tablet). The material used is approximately 500 collected and measured cases. The study shows that the reliability is high and that accuracies around 15mm can be achieved even if the equipment and routines used are relatively simple. The effects of further development using video cameras for data capture and digital images for measurements are discussed.

Accidents, Traffic↗

PubMed1992

Sleep apnea syndrome symptoms and automobile driving in a general population.

Automobile accidents are reported as being overrepresented in those suffering from the obstructive sleep apnea syndrome (SAS), evident by snoring, sleep disturbances and diurnal hypersomnia. An estimation of the prevalence of these symptoms amongst an adult population, predominantly automobile drivers, was assessed by using a one-stage questionnaire procedure. From a national random sample of 1214 persons a weighted reply rate of 76% was achieved. Snoring, breath cessations, mid-sleep awakenings, and diurnal hypersomnia were reported in 24, 3.8, 27 and 9.1%, respectively. The maximum prevalence of SAS was estimated as 2.8-5.5% among men, aged 30-69 years, depending on definition used. Driving frequency in potential sleep apneics was similar to that of the entire population studied. Diurnal hypersomnia, considered a consequence of SAS, was reported as an overall 2.2%, corresponding to 100,000 automobile drivers in Sweden.

Adult↗

PubMed1990

Clinical symptoms of sleep apnea syndrome and automobile accidents.

Patients with clinical features of sleep apnea syndrome (SAS) and self-reported sleep spells at the wheel do poorly in simulated monotonous driving. To evaluate whether drivers with defined symptoms of SAS (heavy snoring, sleep disturbances and daytime sleepiness) compensate in real traffic by careful driving or not, the rate of car accidents over a 5-year period was investigated. A questionnaire was addressed to 140 patients with and 142 controls without symptoms associated to SAS. Seventy-three of the patients had a complete triad of SAS-associated symptoms. Fifty-two percent of these patients reported habitual sleep spells at the wheel, as opposed to less than one percent by the controls. The ratio of drivers being involved in one or more combined-car accident was similar for patients and control drivers, but for single-car accidents the ratio was about 7 times higher for patients with a complete triad of symptoms of SAS compared to controls (p less than 0.001). When corrected for mileage driven, the total number of single-car accidents was almost 12 times higher among patients with sleep spells whilst driving, compared to controls (p less than 0.001). It is concluded that drivers with the clinical features of SAS are at increased risk especially for single-car accidents and that the risk seems to vary with the severity of symptoms.

Accidents, Traffic↗

PubMed1989

Measurement of spinal sagittal configuration and mobility with Debrunner's kyphometer.

A considerable number of instruments have been described for noninvasive measurements of the sagittal configuration and mobility of the thoracolumbar spine. With Debrunner's kyphometer, it is possible to obtain this information in approximately 1 minute in a clinical setting. A minor modification of the kyphometer to increase its range of measurement of lumbar extension is described. Repeatability of measurements with the instrument was studied on 31 healthy individuals in a randomized cross-over model. In another study, ten individuals were examined ten times each by the same investigator within 3 weeks. These studies showed good reproducibility for measurements with the kyphometer. The importance of standardized instructions for measurement procedures is emphasized. The statistical approach to repeatability of measurements is discussed.

Adolescent↗

PubMed1987

Children in cars. Some aspects of the safety of children as car passengers in road traffic accidents.

The purpose of this study was to investigate child safety in cars from different aspects, such as the epidemiology of child injuries and injury assessment, restraint use effectiveness, restraint use limitations and drawbacks, data quality and improper use of child restraints. The materials used for the studies were of different types and sizes. Insurance materials were used for the epidemiological investigation and supplemented with questionnaires, for studies of restraint use effectiveness. Data on injuries reported by the police were used for studies of data quality and of the limitations and drawbacks of restraint use. Observational studies were conducted to detect improper use of child restraints and these were followed-up by dynamic barrier tests to assess possible consequences in frontal collisions. All injuries were classified according to the Abbreviated Injury Scale (AIS) and the risk of death and disability was predicted by RSC (Rating system for Serious Consequences) with modified figures for children. The main conclusions reached were that injury assessing methods derived for adults can be used also for children with some modifications concerning disability risks. Child restraint use was found to be effective in reducing injuries, especially the use of rearward-facing restraints. Injuries occurring in spite of restraint use were often minor in terms of fatality risks, but injuries to the neck and head may cause long-term consequences. The police was found to report only slightly more than half of the injured children reported to the insurance company. Misuse of child restraints was found to exist and may decrease restraint use effectiveness or induce injuries. On the basis of these studies it is recommended that child restraints be incorporated into cars as an in-built system with the same basic design as restraints that are available as extra equipment. Certain considerations should be paid, however, to those injuries occurring among restrained children that entail a risk of medical disability.

Accidents, Traffic↗

PubMed1986

Epidemiology of head injuries in Sweden.

The estimated number and cause of head injuries in Sweden are discussed. Head injuries are common in many activities and the need of head protection is stressed.

Accidents, Occupational↗

PubMed1986

Acute injury statistics--a true picture?

The official data on traffic victims are based on police-reported accidents. Many authors have shown that these data are not fully representative. In order to obtain reliable accident statistics, it is suggested that these be based primarily on injured persons with long-term consequences.

Accidents, Traffic↗

PubMed1986

Acute injury scaling related to residual disability.

Injury scaling is an important issue in the traffic safety field. A comparison was made between the severity of injuries as graded according to the Abbreviated Injury Scale (AIS) and the severity 5 years after the accident. It was found that among persons with permanent medical disability greater than or equal to 10%, 20% were given an AIS score of 1, i.e. they were initially judged as having a slight injury. This implies that the AIS scale needs to be re-evaluated to take into account possible long-term consequences.

Accidents, Traffic↗