# Developmental Screening System for Patient Vibration Signals with Knee Disorder
## 3 Results and Discussion
### Ligament after Recovery Assessment  
The collected data were divided into control group data (C1-C27) and experimental group data (E1-E38). Tables 1-3 list the average data from the two groups. Similar to the results obtained before ligament surgery, the postoperative values derived at TP\({}_{\rm MCL}\) and TP\({}_{\rm LCL}\) revealed significantly lower variation, compared with the average value derived at TP\({}_{\rm ACL}\). The average value of the experimental group was significantly greater than that of the control group. The highest level of this difference was nearly 10.1 times, whereas the lowest was approximately 2.6 times. The sound signals of the two limbs were comparable after ACL reconstruction. Thus, the wavelet coefficients derived through DTW can serve as a basis for assessing postoperative recovery. In both the experimental and control groups, the knee wavelet coefficients derived at TP\({}_{\text{MCL}}\), TP\({}_{\text{ACL}}\), and TP\({}_{\text{LCL}}\) were compared at 1 month, 2 months, 3 months, 6 months, and 1 year postoperatively. Figures 3-6 present the average differences in the knee wavelet coefficients for each band. For the experimental group at TP\({}_{\text{MCL}}\), the mean difference in the knee wavelet coefficient derived before surgery increased nearly two-fold at 1 month postoperatively. One year after surgery, the wavelet coefficient difference of the bands had increased to 0.74-2.44. For the experimental group at TP\({}_{\text{ACL}}\), the mean difference in the knee wavelet coefficients before surgery was significantly lower (1.67 times) than that at 1 month postoperatively. However, the differences in the bands increased after 2-3 months postoperatively. The differences in the wavelet coefficients at 1 year postoperatively had decreased to a value similar to that obtained 1 month after surgery. The values decreased by at least 2.74-fold compared with those derived before surgery. For the experimental group, the mean difference in the wavelet coefficients at TP\({}_{\text{LCL}}\) decreased slightly compared with those at 1 month postoperatively. The difference increased at 3 months and 1 year postoperatively. The values decreased by 1.1-fold compared with the difference in bands before surgery. Tissues form a normal link between the bones after ACL reconstruction surgery to reduce the rate of wear and tear between the bones. As such, the analysis results described here can be used as an indicator of the degree of ligament stabilization during recovery. Additionally, the results revealed that the differences in the signal performance of the injured limb gradually decreased with recovery. After 1 month postoperatively, the difference decreased rapidly. This was attributed to healing of the surgical wound. Internal residual water and blood secretions have a similar lubricating function and reduce the coefficient of friction. The difference increased slightly, then gradually stabilized over time. Thus, the screening tool presented in this work shows great potential in its ability to monitor the rehabilitation progression following treatment/surgery of the knee joint. Here we present our preliminary results. Further testing of this tool by professionals in the field is required.