Experiment Studies Of The Measurement System Of Spinal Facet Joint Capsule Strain And Pain

The sequelae of neck injury with a high proportion in traffic accident injuries hadinfluence on victims for a long time. Neck injury was commonly known as whiplashinjuries，and the main cause of it was rear-end collision. The pain mechanism ofwhiplash injury was mainly that excessive deformation of spinal joint caused the nervestimulated or damaged resulting in pain. Although the mechanism had been confirmedby more and more experimental studies, the relationship between the strain andneurophysiology of cervical joint capsule in whiplash injury were not quantified. Thusthe measurement system of strain and pain of spinal joint capsule were designed tofurther reveal the relationship between strain and neural discharge activity.In this paper，the following exploratory research and experiments had finished:①according to the cervical spinal joint capsule morphology and structure, theanimal model and physical model were designed. Because the morphology of spinaljoint capsule between goat and human were similar, the goat was used to experimentalstudes. A physical model for whiplash injury simulation was designed and fabricated totest the measurement system of spinal joint capsule strain.②The measurement system of strain of spinal joint capsule was designed tomeasure the strain conditions of joint capsule with whiplash injury, which consists ofthe joint capsule strain sensors, signal conditioning circuitry and data acquisitiondevices. The joint capsule strain sensor was a rubber tube containing liquid metal. Theoutput of measuring bridge was non-linear due to a big strain, and the approximationerror of the sensor static nonlinear model was controlled by the order. The calibrationsfor the joint capsule strain sensor through experiments. The static indexes, such as ittingerror, hysteresis, repeatability, sensitivity, resolution, threshold and the static error, weredetermined. Because the output of joint capsule strain sensor is nonlinear, the inversionof the output signal was determined by the approximate inverse function.③For detecting the spinal joint capsule pain wwith whiplash injury, Themeasurement system of pain of spinal joint capsule was designed. By the neuraldischarge detection electrode connecting the joint capsule disposable nerve root, theconduction of pain signals were precessed through the A/D differential amplifier and thehigh-speed recording data acquisition device, and ultimately were analyzed by thededicated software. The neural discharge electrode was made of platinum wire and wax substrate, connectig to the spinal joint capsule nerve root rootlets. Pain signalscontained a variety of nerve impulses signal, thus the different nerve fiber dischargeaction potentials were screened and saved as templates by using the electricalstimulation experiment. Finally, the nerve discharge conditions of joint capsule withwhiplash injury were determined by a match technique.④The application experiments of the measurement systems of strain and pain ofspinal joint capsule were finished. Designed whiplash injury simulation system consistsof a swing arm injuries platform, rear-end collision data acquisition systems, high-speedcamera system and laser velocimetry system. The testing of the measurement systems ofstrain of spinal joint capsule was completed. Finally, application experiment project ofthe measurement systems of spinal joint was designed.