In order to maintain good communication between the optical tracking system and image-based surgical navigation software through the serial port, we developed a serial communication software by calling the WinAPI function with Visual C++ 6.0. We then completed the data reading, integration and analysis. We further calculated the relative position between the surgical instruments and the patient coordinate system, realized the registration between the CT model data and the spatial location of patient by using ICP algorithm, and finally achieved real-time tracking surgical instruments on the surgery. The practical effects of clinical surgery have proved that this system has good robustness, real-time property and reliability, which can meet the requirements of clinical surgery.
Algorithms ; Automatic Data Processing ; instrumentation ; Computer Simulation ; Humans ; Image Processing, Computer-Assisted ; instrumentation ; Imaging, Three-Dimensional ; instrumentation ; Software ; Surgery, Computer-Assisted ; instrumentation ; methods ; Tomography, X-Ray Computed ; instrumentation ; User-Computer Interface

Objective:To explore the effects of type 2 diabetes mellitus (T2DM) on the levels of serum magnesium in patients with community-acquired pneumonia (CAP) and the effects of abnormal serum magnesium on the prognosis in T2DM patients with CAP.Methods:The study was a retrospective single-center study conducted in adult patients hospitalized with CAP at the First Hospital of Qinhuangdao between January 2015 and December 2018. These patients were divided into two groups according to the diagnosis of T2DM (control group and T2DM group). The reference range for serum magnesium is from 0.75 to 1.25 mmol/L. The primary endpoint was in-hospital mortality.Results:The prevalences of hypomagnesemia and hypermagnesemia were numerically higher in T2DM group than in control group (hypomagnesemia: 14.6% vs 12.0%, hypermagnesemia: 1.4% vs 0.7%), but there was no statistical difference ( P>0.05). In patients with T2DM, the in-hospital mortalities in patients with normal serum magnesium and hypomagnesemia were 5.9% and 12.7%, respectively; In multivariate logistic regression analysis, the in-hospital mortality of patients with hypomagnesemia was 5.629(95% CI 2.012-15.750, P=0.001)times as much as that of patients with normal serum magnesium. Conclusions:Abnormal serum magnesium was common in T2DM inpatients with CAP and hypomagnesemia was the most common. Hypomagnesemia was closely related to in-hospital mortality in T2DM patients with CAP. The assessment of serum magnesium levels on admission may be helpful in predicting the prognosis of T2DM patients with CAP.