ROM Measurement System Based On Skinned Mesh

Range of motion(ROM)is the rotation angle when joint do full capacity movement.ROM mesurment play an important role in the evaluation of human body joint,and it has important meaning in the field of disable grade appraisal and rehabilitation medicine.At present,most of motion measurement in domestic use the method of general protractor.The method is simple,while with poor precision.On the international,method with more precision,such as Human Norm system,CROM series,has a complex operation and expensive price.To cope with domestic clinical needs,we are mean to design an accurate,repeatable,real time,low cost and reliable human motion measurement system.The design thought is using software with the support of optical positioning system to accomplish the goal.Optical positioning system transmit the data of marker position into computer,and then software on the computer calculate the angle according to affine transformation and the principle of Euler Angle inverse solution,and in the meantime,the results are dispalyed real-time.In order to show the process vividly,we introduce the the virtual human body animation based on skin-mesh technology.We implement the real-time three-dimensional human body picture changing with the measured body.To simplify the operation process,we introduced the automatic identification of joints to realize the automation of the measurement.After the contrast experiment with the high-precision electronic protractor,the system shows the characteristics of high precision,high stability.The error is within 0.3 degrees while mean square error within 0.2 degrees.Compared with similar foreign products,the system shortens the measurement time,and the performanee on all aspects achieves the desired requirements.