Intelligent Tapping Machine: Tap Geometry Inspection.

Currently, the majority of industrial metal processing involves the use of taps for cutting. However, existing tap machines require relocation to specialized inspection stations and only assess the condition of the cutting edges for defects. They do not evaluate the quality of the cutting angles and the amount of removed material. Machine vision, a key component of smart manufacturing, is commonly used for visual inspection. Taps are employed for processing various materials. Traditional tap replacement relies on the technician's accumulated empirical experience to determine the service life of the tap. Therefore, we propose the use of visual inspection of the tap's external features to determine whether replacement or regrinding is needed. We examined the bearing surface of the tap and utilized single images to identify the cutting angle, clearance angle, and cone angles. By inspecting the side of the tap, we calculated the wear of each cusp. This inspection process can facilitate the development of a tap life system, allowing for the estimation of the durability and wear of taps and nuts made of different materials. Statistical analysis can be employed to predict the lifespan of taps in production lines. Experimental error is 16 µm. Wear from tapping 60 times is equivalent to 8 s of electric grinding. We have introduced a parameter, thread removal quantity, which has not been proposed by anyone else.

A Meta-Analysis and Systematic Review of the Incidences of Complications Following Facial Thread-Lifting.

BACKGROUND: Facial thread-lifting (FTL) has gained more popularity, but the incidences of complications following FTL remain controversial. We aimed to perform a meta-analysis and systematic review to estimate the incidences of complications and to compare the short- and long-term satisfaction rates following FTL. METHODS: We searched PubMed, Web of Science, Embase and Cochrane library for eligible studies. The primary outcome was the incidences of complications following FTL. The secondary outcome was the satisfaction rate immediately and 6-month after FTL. The pooled incidences of complications and 95% confidence intervals were estimated using random-effects models. RESULTS: A total of 26 studies were included in this meta-analysis. Swelling was the most commonly reported complication with a pooled incidence of 35%, followed by skin dimpling (10%), paresthesia (6%), thread visibility/palpability (4%), infection (2%), and thread extrusion (2%). Absorbable threads were associated with a significantly lower risk of paresthesia (3.1% vs. 11.7%) and thread extrusion (1.6% vs. 7.6%) than non-absorbable threads. Patients older than 50 years had a significantly higher risk of dimpling (16% vs. 5.6%) and infection (5.9% vs. 0.7%) than their younger counterparts. In addition, the pooled long-term satisfaction rate was significantly decreased compared to it immediately after FTL (88% vs. 98%). CONCLUSION: Non-absorbable threads and older age of patients are associated with higher risks of complications. Therefore, we recommend a judicious use of non-absorbable threads and FLT in older patients. Furthermore, it should be discussed with patients preoperatively that the rejuvenation effect of FTL may not maintain in the long-term. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Effects of merged holes, partial thread removal, and offset holes on fatigue strengths of titanium locking plates.

BACKGROUND: This study investigated the effects of screw hole merging, thread removal, and screw hole offset on the mechanical properties of locking plates. METHODS: Finite element models were used to develop the optimal design of the merged holes. Four titanium locking plates with different hole designs were analyzed. Type I had threaded round holes. Type II had merged holes. Type III had merged holes with partial thread removal. Type IV had threaded offset holes. Mechanical experiments similar to finite element analyses were conducted and compared. Screw bending tests were used to assess the screw holding power. FINDINGS: Finite element analyses showed the optimal merging distance between two round screw holes was 3.5 mm with 2/3 circumferences in each hole. The stresses of types II and III were respectively 6.42% and 7.33%, lower than that of type I. The stress of type IV was 1.66% higher than that of type I. In the mechanical tests, the fatigue lives of types II and III were respectively 3.86 and 7.16 times higher than that of type I. The fatigue life of type IV was 37% lower than that of type I. The differences in the bending strengths of screws were insignificant. INTERPRETATION: Merging holes could mitigate screw hole stress and increase the fatigue lives of the plates significantly. Partial thread removal could further improve the fatigue life. Merging holes and thread removal did not decrease the screw holding power significantly. The fatigue lives were significantly decreased in plates with offset holes.