A Portable Pressure and Force Line Trajectory Measuring System for Unicondylar Knee Arthroplasty.

The pressure and force line trajectory of the distal femoral prosthesis relative to the prosthesis gasket are key factors in judging the appropriate position of implants in unicondylar knee arthroplasty (UKA) surgeries, which is critical to the success of UKA surgeries. In this paper, we propose a portable pressure and force line trajectory measurement system, which includes a pressure sensors array, an analog-to-digital converter (ADC), and a microcontroller unit (MCU). Data from twenty sensors is obtained through time-sharing scanning and transmitted to the host computer through the USB interface. We put forward an algorithm to calculate pressure value and fit the force line trajectory for better accuracy. Both the pressure value and force line trajectory are calculated and displayed on the screen of the host computer by developed software in real-time. The experiments results show that the root mean square error of fitting force line trajectory in the experiments is ±0.342mm, which has 63% reduction compared with that in the previous work, and the average pressure value measurement error is 10.03%. Besides, the pressure sensors array, the ADC and the MCU in the system are integrated in a portable handle, which is easier for clinic trial.Clinical Relevance-This system can assist doctors to improve the success rate of unicondylar knee arthroplasty and reduce patient's pain.

Long-Term Bowel Sound Monitoring and Segmentation by Wearable Devices and Convolutional Neural Networks.

Bowel sounds (BSs), typically generated by the intestinal peristalses, are a significant physiological indicator of the digestive system's health condition. In this study, a wearable BS monitoring system is presented for long-term BS monitoring. The system features a wearable BS sensor that can record BSs for days long and transmit them wirelessly in real-time. With the system, a total of 20 subjects' BS data under the hospital environment were collected. Each subject is recorded for 24 hours. Through manual screening and annotation, from every subject's BS data, 400 segments were extracted, in which half are BS event-contained segments. Thus, a BS dataset that contains 20 × 400 sound segments is formed. Afterwards, CNNs are introduced for BS segment recognition. Specifically, this study proposes a novel CNN design method that makes it possible to transfer the popular CNN modules in image recognition into the BS segmentation domain. Experimental results show that in holdout evaluation with corrected labels, the designed CNN model achieves a moderate accuracy of 91.8% and the highest sensitivity of 97.0% compared with the similar works. In cross validation with noisy labels, the designed CNN delivers the best generability. By using a CNN visualizing technique-class activation maps, it is found that the designed CNN has learned the effective features of BS events. Finally, the proposed CNN design method is scalable to different sizes of datasets.

Monitoring hip posture in total hip arthroplasty using an inertial measurement unit-based hip smart trial system: An in vitro validation experiment using a fixed pelvis model.

Intraoperative measurement of hip posture is the basis for assessing hip range of motion (ROM) and predicting postoperative functional limits allowable for activities of daily living. Although computer navigation for total hip arthroplasty (THA) has improved the accuracy of intraoperative ROM evaluation, it has not gained widespread popularity due to its complex and time-consuming protocol. We therefore developed an inertial measurement unit-based hip smart trial system (IMUHST) for intraoperative monitoring of hip posture. An in vitro validation experiment was conducted using bone models with a three-dimensional measurement model as the reference standard. The absolute mean error, Bland - Altman analysis and intra-class correlation coefficient demonstrated that the validity and reliability of this system meets the requirement for clinical application. Given that monitoring posture is the basis for evaluating the direction(s) of potential impingement, subluxation and dislocation, the IMUHST is a promising development direction of computer assisted surgery in THA.

Association between cytotoxic T lymphocyte antigen-4 +49A/G, -1722T/C, and -1661A/G polymorphisms and cancer risk: a meta-analysis.

Cytotoxic T lymphocyte antigen-4 (CTLA-4), a key gene that contributes to the susceptibility and clinical course of cancer, is an important down-regulator of T cell activation and proliferation. The +49A/G polymorphism is commonly studied because of its association with cancer risks. However, other polymorphisms, such as -1722T/C and -1661A/G, have not been studied in detail. We performed a meta-analysis using 43 eligible case-control studies with a total of 19,089 patients and 21,388 controls to examine the association between CTLA-4 +49A/G, -1722T/C, and -1661A/G polymorphisms and cancer risk. We searched the PubMed and EMBASE databases for all articles published up to July 17, 2013. Individuals with the +49 A allele (AA/AG vs. GG, odds ratio (OR) = 1.21, 95% confidence interval (95% CI) = 1.16-1.27) and -1661 G allele (AG/GG vs. AA, OR = 1.52, 95% CI = 1.34-1.73) had increased cancer risk. However, no significant association between cancer risk and the -1722T/C polymorphism was found (CC/CT vs. TT, OR = 1.04, 95% CI = 0.92-1.16). In subgroup analysis for the +49A/G polymorphism, increased cancer risk remained in the subgroups of Asians (OR = 1.25, 95 % CI = 1.18-1.31), patients with breast cancer (OR = 1.28, 95% CI = 1.15-1.42), and patients with lung cancer (OR = 1.20, 95 % CI = 1.07-1.35). For the -1661A/G polymorphism, increased cancer risk remained in the subgroups of Asians (OR = 1.52, 95% CI = 1.34-1.73), patients with breast cancer (OR = 1.48, 95% CI = 1.07-2.03), and patients with oral cancer (OR = 3.16, 95% CI = 1.84-5.45). However, no significant increase in cancer risk was found in the subgroups for the -1722T/C polymorphism. In conclusion, the results suggest that +49A/G and -1661A/G polymorphisms in CTLA-4 are risk factors for cancers, whereas the -1722T/C polymorphism is not associated with an increased risk of cancer.