To meet the need of accurate positioning for biopsy gun in the breast biopsy operation, a new stereotactic biopsy guide device have been developed to adapt to the domestic mammary machine, which can help physician to carry out biopsy operation more accurately and effectively. The guide device has the motion model, measurement model and display model and can realize linear motion and display real-time displacement values in X, Y and Z direction. The experimental results showed that the guide device could be well fixed in the domestic mammary machine, and achieved good accuracy and repeatability in each direction. Depending on the displacement values, physician can change the space of biopsy gun accurately.
Biopsy, Needle ; instrumentation ; methods ; Breast ; pathology ; Equipment Design ; Female ; Humans ; Stereotaxic Techniques ; instrumentation

Objective: To explore the methods of establishing and maintaining community injecting drug user (IDU) cohort. Methods: From June 2014 to June 2017, a community survey was conducted on basis of local needle and syringe exchange site to recruit 200 HIV sero-negative IDU for a prospective cohort study in Longyang district of Baoshan city, Yunan province. Follow-up was carried out every six month to investigate high risk drug use behavior and sexual behavior, and blood samples were collected from them for the tests of HIV and HCV serum antibodies. The cohort would be opened every 12 months to replenish the cohort to 200 subjects. Results: The follow up was conducted for 3 years in 229 IDUs. Cohort follow-up rate was 93.0% (213/229) for 6 months, 92.1% (211/229) for 12 months, 91.7% (200/218) for 18 months, 87.2% (190/218) for 24 months, 86.0% (172/200) for 30 months and 86.0% (172/200) for 36 months. Conclusion The community IDU cohort has a high follow-up rate.