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Purpose: To compare the dosimetric effects of American Association of Physicists in Medicine (AAPM) TG43 dose formalism and AcurosBV ( grid-based Boltzmann solver ,GBBS) formalism on High-dose-rate(HDR) brachytherapy planning for cervical cancer patients irradiated using three different applicators.Methods: A TG43 plan and a AcurosBV plan were generated for each of the 30 patients. twenty patients who had undergone whole pelvic radiotherapy followed by cervical HDR brachytherapy and the remaining 10 patients who underwent total hysterectomy only gave HDR brachytherapy also were enrolled in this study. The patients were divided into three groups according to the types of applicators used: tandem and ovoid (T&O), tandem and ring (T&R), and Cylinder. To compare the dosimetric parameters, the cumulative dose-volume histograms (DVHs) were measured. We also compared the doses at 90% of the volume (D90%) , the volume receiving 100% and 150% of the prescribed dose (V100% and V150%) for the clinical target volume (CTV-HR) and the doses of point A, the dose receiving 0.1 cc and 2 cc of the volume (D0.1cc and D2cc) for the organs-at-risk (OARs).Results: In this study, compared with the AcurosBV plans, TG43 plans predicted higher D90%, V100%, and V150% of CTV-HR, dose of point A and D0.1cc and D2cc of OARs in three types of applicators. Except D2cc of sigmoid in T&R and Cylinder applicators, the D90%, V100%, and V150% of CTV-HR; the Dose of point A and the D0.1cc and D2cc of bladder, recutum and small bowel exhibited significant discrepancies (P>0.05). The effects of the three types of applicators on the dose distribution were quite different due to the difference of the materials: The dose difference of CTV-HR and OARs was greatest (around 10%) for T&O applicators but only 1%-5% for T&R and Cylinder applicators.Conclusions: This study demonstrated that AcurosBV was more accurate in calculating the doses in the air cavity and high-density substance than TG43. In the clinical setting, the AcurosBV exhibited different dosimetric distributions in the cervix plans for HDR brachytherapy, especially in treatment planning when using T&O applicators. The AcurosBV algorithm should be considered when using T&O applicators or some other materials with a much higher or lower density (metal or air) than soft tissue. Howevere, If the density is close to the soft tissue, considering AcurosBV algorithm requires more calculation time, TG43 could still be selected when using applicators in clinical.

OBJECTIVEThe authors sought to compare the dosimetric quality of hypofractionated stereotactic radiosurgery in treating sizeable brain tumors across the following treatment platforms: GammaKnife (GK) Icon, CyberKnife (CK) G4, volumetric modulated arc therapy (VMAT) on the Varian TrueBeam STx, double scattering proton therapy (DSPT) on the Mevion S250, and intensity modulated proton therapy (IMPT) on the Varian ProBeam.METHODSIn this retrospective study, stereotactic radiotherapy treatment plans were generated for 10 patients with sizeable brain tumors (> 3 cm in longest diameter) who had been treated with VMAT. Six treatment plans, 20–30 Gy in 5 fractions, were generated for each patient using the same constraints for each of the following radiosurgical methods: 1) GK, 2) CK, 3) coplanar arc VMAT (VMAT-C), 4) noncoplanar arc VMAT (VMAT-NC), 5) DSPT, and 6) IMPT. The coverage; conformity index; gradient index (GI); homogeneity index; mean and maximum point dose of organs at risk; total dose volume (V) in Gy to the normal brain for 2 Gy (V2), 5 Gy (V5), and 12 Gy (V12); and integral dose were compared across all platforms.RESULTSAmong the 6 techniques, GK consistently produced a sharper dose falloff despite a greater central target dose. GK gave the lowest GI, with a mean of 2.7 ± 0.1, followed by CK (2.9 ± 0.1), VMAT-NC (3.1 ± 0.3), and VMAT-C (3.5 ± 0.3). The highest mean GIs for the proton beam treatments were 3.8 ± 0.4 for DSPT and 3.9 ± 0.4 for IMPT. The GK consistently targeted the lowest normal brain volume, delivering 5 to 12 Gy when treating relatively smaller- to intermediate-sized lesions (less than 15–20 cm3). Yet, the differences across the 6 modalities relative to GK decreased with the increase of target volume. In particular, the proton treatments delivered the lowest V5 to the normal brain when the target size was over 15–20 cm3 and also produced the lowest integral dose to the normal brain regardless of the target size.CONCLUSIONSThis study provides an insightful understanding of dosimetric quality from both photon and proton treatment across the most advanced stereotactic radiotherapy platforms.

Background Both plan quality and robustness were investigated through comparing some dosimetric metrics between intensity modulated proton therapy (IMPT) and helical tomotherapy based intensity modulated radiotherapy (IMRT) for cervical cancer. Methods Both a spot-scanning robust (SRO) IMPT plan and a helical tomotherapy robust (TRO) IMRT plan were generated for each of 18 patients. In order to evaluate the quality of nominal plans without dose perturbations, planning scores (PS) on clinical target volume (CTV) and five organs at risk (OARs) based on clinical experience, and normal tissue complication probabilities (NTCP) of rectum and sigmoid were calculated based on Lyman-Kutcher-Burman (LKB) model. Dose volume histogram bands width (DVHBW) were calculated in 28 perturbed scenarios to evaluate plan robustness. Results Compared with TRO, the average scores of SRO nominal plans were higher in target metrics [V46.8Gy, V50Gy, Conformity and Homogeneity](16.5 vs. 15.1), and in OARs metrics (60.9 vs. 53.3), including bladder [V35,V45, Dmean,D2cc], rectum [V40,V45,D2cc,Dmax], bowel [V35,V40,V45, Dmax], sigmoid [V40,Dmax] and femoral heads [V30,Dmax]. Meanwhile, NTCP calculation showed that the toxicities of rectum and sigmoid in SRO were lower than those in TRO (rectum: 2.8% vs. 4.8%, p Conclusion Better CTV coverage and OAR Sparing were obtained in SRO nominal plan. Based on NTCP calculation, SRO was expected to allow a small reduction in rectal toxicity. Furthermore, SRO generated a more robust plan in CTV target coverage.

Background Tumor motion may compromise the accuracy of liver stereotactic radiotherapy. In order to carry out a precise planning, estimating liver tumor motion during radiotherapy has received a lot of attention. Previous approach may have difficult to deal with image data corrupted by noise. The iterative closest point (ICP) algorithm is widely used for estimating the rigid registration of three-dimensional point sets when these data were dense or corrupted. In the light of this, our study estimated the three-dimensional (3D) rigid motion of liver tumors during stereotactic liver radiotherapy using reconstructed 3D coordinates of fiducials based on the ICP algorithm. Methods Four hundred ninety-five pairs of orthogonal kilovoltage (KV) images from the CyberKnife stereo imaging system for 12 patients were used in this study. For each pair of images, the 3D coordinates of fiducial markers inside the liver were calculated via geometric derivations. The 3D coordinates were used to calculate the real-time translational and rotational motion of liver tumors around three axes via an ICP algorithm. The residual error was also investigated both with and without rotational correction. Results The translational shifts of liver tumors in left-right (LR), anterior-posterior (AP),and superior-inferior (SI) directions were 2.92 ± 1.98 mm, 5.54 ± 3.12 mm, and 16.22 ± 5.86 mm, respectively; the rotational angles in left-right (LR), anterior-posterior (AP), and superior-inferior (SI) directions were 3.95° ± 3.08°, 4.93° ± 2.90°, and 4.09° ± 1.99°, respectively. Rotational correction decreased 3D fiducial displacement from 1.19 ± 0.35 mm to 0.65 ± 0.24 mm (P Conclusions The maximum translational movement occurred in the SI direction. Rotational correction decreased fiducial displacements and increased tumor tracking accuracy.

Purpose This study aimed to evaluate the clinical impact of hybrid intensity-modulated radiotherapy (IMRT) and hybrid volumetric-modulated arc therapy (VMAT) for early-stage breast cancer, including plan quality and second cancer risk (SCR). Methods Three different plans were designed in full IMRT, hybrid IMRT, and hybrid VMAT for each of eight patients with early-stage breast cancer. Target quality, organs at risk (OARs) sparing, and SCR were compared among the three plans. Results Compared with the hybrid IMRT, full IMRT showed deterioration in terms of D2% of simultaneous integrated boost (SIB), V10 of ipsilateral lung, and excess absolute risk (EAR) to contralateral lung and esophagus. The homogeneity index (HI) of SIB, V5 of ipsilateral lung and combined lung, the Dmax and Dmean of the esophagus, the EAR to contralateral breast and lung, and the EAR to the esophagus with hybrid VMAT dramatically increased by 12.5%, 19.49%, 18.87%, 90.59%, 167.69%, 50.14%, 264.68%, and 160.95%, respectively (p = 0.022; 0.040; 0.044; 0.041; 0.003; 0.020; 0.000; 0.003). The EAR to contralateral breast and contralateral lung by full IMRT was significantly decreased compared with the hybrid VMAT (26.97%, p = 0.033; 50.01%, p = 0.026). Conclusion The results confirmed that hybrid IMRT could achieve better target quality and OARs sparing than full IMRT and hybrid VMAT for early-stage right breast cancer. Hybrid IMRT was the best treatment option, while hybrid VMAT performed the worst among the three plans in terms of SCR to peripheral OARs.

Objective This study analyzed different definitions of the conformity index (CI), homogeneity index (HI), and gradient index (GI) used in evaluation of prostate cancer stereotactic body radiation therapy. Methods A total of 10 patients with localized prostate cancer staged T1–T2a were selected randomly, from which two stereotactic body radiation therapy plans were designed with CyberKnife and EDGE systems for each patient based on the same images and contours. CI, HI, and GI with different definitions were calculated based on a dose‐volume histogram of treatment plans. Results For four definitions of CI, the results showed that the values calculated by the Radiation Therapy Oncology Group, Lomax and Scheib, and Van't Riet were closer to 1 for EDGE plans, except for that by the Saint‐Anne, Lariboisiere, and Tenon group. Meanwhile, CI values of Van't Riet et al were lower than other definitions, which showed high accuracy to describe the conformity between the target volume and prescribed isodose line. For five definitions of HI, CyberKnife plans showed lower values than EDGE plans. HI calculated based on the D2 (D5) and D98 (D95) were lower than that calculated by the Dmax to Dmin, whereas the standard deviation was higher than others. For the dose GI, the results of effective radius and modified GI showed that EDGE plans had a steeper dose fall‐off, which is inverse to the conventional GI. Conclusions These indexes can all be objective tools for the evaluation of plan quality. Our results showed better conformity of dose distribution and dose gradient for EDGE plans, but better uniformity for CyberKnife plans. The conformation number and S‐index were recommended to accurately describe the conformity and uniformity of dose distribution. The ∆Riso and modified GI were also recommended to calculate the dose gradient.

To explore the feasibility of using Volumetric-Modulated Arc Therapy (VMAT) to protect left anterior descending branch (LAD) after breast-conserving surgery for left breast cancer. 15 left breast cancer patients after breast-conserving surgery were selected. 7F-IMRT and 2A-VMAT treatment plans were designed with Varian Eclipse TPS (13.6version). The prescriptions of PTV and PTV Boost were 43.5Gy and 49.5Gy in 15 fractions. The dosimetric parameters, OARs dose sparing and second cancer risk (SCR) were compared between the two plans using a paired t-test. The VMAT plans obtain better PTV conformity and higher mean dose. VMAT plans show a better dose distribution in high dose areas and better sparing of OARs, including left lung, heart, and LAD. The Dmax and Dmean of LAD decreased significantly in VMAT plans. The SCRs of the contralateral lung and breast significantly increased with a higher mean dose. We recommend that contouring and evaluating the dose of LAD and LAD helping structures in left breast cancer radiotherapy. SCR should be evaluated for younger patients.

Aims The aim of this study was to make a quantitative comparison of plan quality between MLC-based EDGE system and the cone-based CyberKnife system in stereotactic body radiation therapy (SBRT) for patients with localized prostate cancer. Materials and methods Ten patients with prostate volumes ranging from 34.65 to 82.16 cc were used for prostate SBRT. Treatment plans were created for both EDGE and CyberKnife G4 systems using the same dose-volume constraints. Dosimetric indices including Planning Tumor Volume (PTV) coverage, conformity index (CI), new conformity index (nCI), homogeneity index (HI), gradient index (GI) were applied for target, while the sparing of critical organs, including bladder, rectum, femoral heads, urethra, penile bulk and normal tissue outside PTV), were evaluated interms of various dose-volume metrics and integral dose (ID). Meanwhile, the required delivery time and number of monitor units (MUs) during irradiation were measured to estimate the treatment efficiency. The radiobiological indices such as equivalent uniform dose (EUD), tumor control probability (TCP) and the normal tissue complication probability (NTCP) were also analyzed. Results All dose constraints were achieved by both systems. It showed that the DEGE plans results were closest to the CK plans results in terms of PTV coverage, HI and GI. For EDGE, more conformal dose distribution in the target as well as reduced exposure of critical organs were obtained together with reduction of 91% delivery time and 72% monitor units. EDGE plans also got lower EUD for bladder, rectum, urethra and penile bulk, which associated with reduction of NTCPs. However, higher values of EUD and TCP for tumor were obtained with CK plans. Conclusions Our study indicated that both systems were capable of producing almost equivalent plan quality and can meet clinical requirements. CyberKnife G4 system has higher target dose while EDGE system has more advantages based on the considerations of normal tissue sparing and delivery efficiency. With abundant clinical experience, CK provides accurate SBRT treatment with high quality. EDGE system also can be considered to be an option for SBRT treatment for localized prostate cancer treatment.

Speech Emotion Detection (SED) aims to recognize the classification of each emotion in a continuous speech, and to pinpoint their onset and offset time. Although there is extensive research on emotion recognition, the research about detection is relatively less. In this paper, we propose a novel model for SED using the sliding window method for feature extraction and Artificial Neural Network (ANN) for modeling. As for feature extraction, we firstly introduce the window-level feature which is extracted by emotion recognition utilizing sliding window. Then, using Gaussian distribution to approximate the distribution of emotion contribution from interval-level to window-level in order to calculate the interval-level feature. Finally, ANN is used for model training which uses the fusion of the window-level feature and interval-level feature. We evaluate our model on EMO-DB and experimental results show that the proposed model outperforms baseline significantly.

Aims: The aim of this study was to make a quantitative comparison of plan quality between MLC-based EDGE system and the cone-based CyberKnife system in stereotactic body radiation therapy (SBRT) for patients with localized prostate cancer.Materials and methods: Ten patients with prostate volumes ranging from 34.65 to 82.16 cc were used for prostate SBRT. Treatment plans were created for both EDGE and CyberKnife G4 systems using the same dose-volume constraints. Dosimetric indices including Planning Tumor Volume (PTV) coverage, conformity index (CI), new conformity index (nCI), homogeneity index (HI), gradient index (GI) were applied for target, while the sparing of critical organs, including bladder, rectum, femoral heads, urethra, penile bulk and normal tissue outside PTV), were evaluated interms of various dose-volume metrics and integral dose (ID). Meanwhile, the required delivery time and number of monitor units (MUs) during irradiation were measured to estimate the treatment efficiency. The radiobiological indices such as equivalent uniform dose (EUD), tumor control probability (TCP) and the normal tissue complication probability (NTCP) were also analyzed. Results: All dose constraints were achieved by both systems. It showed that the DEGE plans results were closest to the CK plans results in terms of PTV coverage, HI and GI. For EDGE, more conformal dose distribution in the target as well as reduced exposure of critical organs were obtained together with reduction of 91% delivery time and 72% monitor units. EDGE plans also got lower EUD for bladder, rectum, urethra and penile bulk, which associated with reduction of NTCPs. However, higher values of EUD and TCP for tumor were obtained with CK plans. Conclusions: Our study indicated that both systems were capable of producing almost equivalent plan quality and can meet clinical requirements. CyberKnife G4 system has higher target dose while EDGE system has more advantages based on the considerations of normal tissue sparing and delivery efficiency. With abundant clinical experience, CK provides accurate SBRT treatment with high quality. EDGE system also can be considered to be an option for SBRT treatment for localized prostate cancer treatment.

This paper designs and implements a leg detection system based on laser scan data. People detection is an important function for autonomous navigation robots, especially in strongly interactive application scenarios. Though it's more intuitive to detect people by means of computer vision, it often means more computation, higher latency, and higher hardware costs. In this work, we propose an approach to detect human leg using pure two dimensional laser scan data with higher accuracy. Our system is based on a random forest model for human leg detection. Different from the original solutions, we add a series of feature filtering mechanisms to filter the leg candidates based on their data characteristics. The features will be put into the random forest model after filtering, and the confidence of being human legs will be calculated. Then, we verify the coordinates of the human legs using the map masking mechanism. It verifies the coordinates of the human legs with map data, which greatly reduces the probability that cylindrical objects such as pillars in the environment being misidentified as human legs, removing most of the false positives provided by the random forest model.

One of the key factors to group multi-session recommendation system is about aggregating the preference of all users. To address the specific issues, we propose the Comprehensive Group Similarity Preference Aggregation (CGSPA) algorithm for Group Itinerary Recommendation System implemented in this paper. CGSPA comprehensively considers three aspects to aggregate group preference requirement, which are (1) the average maximum similarity between the recommendation plan and group preference; (2) the difference between the similarity of each session in the recommendation plan and the corresponding preference needs of the user group; (3) the historical similarity between the recommendation plan and group preference. We conduct extensive experiments to verify the preference aggregation performance and the robustness of CGSPA algorithm. We conclude that with different group scales, CGSPA’s group average satisfaction score is higher compared to the traditional preference aggregation algorithms.

This paper designs and implements a vehicle safety robot based on machine vision. When a car breaks down on the highway, the robot can automatically drive to the designated location, place a warning triangle, monitor the coming vehicles, and give the driver an alarm when necessary. The robot can automatically drive back when ordered. The robot uses Lane Detection Algorithm based on OpenCV to detect road line and adjust its driving gesture dynamically, an Optical Flow Alarming Algorithm is implemented to monitor the coming vehicle, and the communication is implemented through a 2.4 GHz module. Through experiments, we measure the TPR (true positive rate) of the Lane Detection Algorithm, we also test the end-to-end computing time of the system and test the stability of the communication of the system. The analysis shows that the design and implementation of the system can meet the requirement of the highway scenario.

Background To identify optimization of dose distributions of target volumes and decrease of radiation doses to normal tissues during stereotactic body radiation therapy (SBRT) for pancreatic cancer with dose-limiting auto-shells. Methods With the same prescription dose, dose constraints of normal organs and calculation algorithm, treatment plans of each eligible patient were re-generated with 3 shells, 5 shells and 7 shells, respectively. The prescription isodose line and beam number of each patient in 3-shell, 5-shell and 7-shell plan remained the same. Hence, a triplet data set of dosimetric parameters was generated and analyzed. Results As the increase of shell number, the conformal index, volumes encompassed by 100% prescription isodose line and 30% prescription isodose line significantly decreased. The new conformal index was higher in 3-shell group than that in 5-shell and 7-shell group. A sharper dose fall-off was found in 5-shell and 7-shell group compared to 3-shell group. And the tumor coverage in 7-shell was better than that of 3-shell and 5-shell. Lower D5cc of the intestine, D10cc of the stomach, Dmax of the spinal cord and smaller V10 of the spleen was confirmed in 7-shell group compared to 3-shell group. Conclusions More conformal dose distributions of target volumes and lower radiation doses to normal organs could be performed with the increase of dose-limiting auto-shells, which may be more beneficial to potential critical organs without established dose constraints.

This paper studies a gesture recognition method based on the sensing of myoelectric signals, establishes a new type of myoelectric signal processing model, and completes the high-precision identification of several specific actions. We propose an assisted rehabilitation system based on this identification method, which can be used to assist therapists to easily supervise the training of patients with motor dysfunction. The system uses the wearable device's myoelectric signal sensing capabilities to capture the patient's exercise action, compare it to the correct motion model, quantify the amount of patient's training, share the patient's exercise data with the therapist to help them supervise the training progress in time.

To provide a modified formula consistent with the Monte Carlo (MC) algorithm for dose calculations during stereotactic ablative body radiotherapy for non–small cell lung cancer. Seventy CyberKnife treatment plans were calculated and analyzed by MC and ray-tracing (RT) algorithms, separately. Parameters of treatment plans were compared, and those associated with differences of dose distributions were analyzed to establish a modified formula. Gross tumor volume and tumor tracking volume (TTV) were defined as the evident disease on the sequences of the window width and level of the lung and the mediastinum. Additionally, the formula was validated by another 20 plans. The prescription dose of the 90 patients was 60 Gy/5f. The RT algorithm overestimated the planning target volume (PTV) D 95 by an average of 8.59 Gy and the gross tumor volume D 99 by an average of 5.84 Gy. The homogeneity index of PTV was underestimated by 0.11 on average, whereas the conformity index and new conformity index was underestimated by 0.05. The RT algorithm overestimated the dose distribution to the spinal cord by 2.23 Gy, the esophagus by 1.96 Gy, the trachea by 1.89 Gy, the left-sided bronchus by 1.77 Gy, the right-sided bronchus by 1.64 Gy, and the heart by 2.16 Gy. The average whole-lung dose volumes of lung tissues and dose volumes of V 5 were overestimated by 2.69 Gy and 7.52%, respectively. A power function distribution ( R 2 = 0.8626) was confirmed between PTV D 95 and TTV volumes. PTV D 95 calculated by the MC algorithm could be computed easily with TTV and PTV D 95 calculated by the RT algorithm based on the formula. The modified equation was more consistent with MC algorithm than with other formula, which could be a reference to those not accessible to the MC algorithm.

This thesis will present the research and practice of traffic lights and traffic signs recognition system based on multicore of FPGA. This system consists of four parts as following: the collection of dynamic images, the preprocessing of gray value, the detection of the edges and the patterning and the judgment of the pattern matching. The multiple cores system is consist of three cores. Each core parallels processes the incoming images from camera collection in terms of different colors and graphic elements. The image data read in from the camera works as the sharing data of the three cores.

To understand the physical process of SRS lasing in SOI waveguides and to optimize the performance of continuouswave Raman silicon lasers, in this paper numerical simulation on the output characteristics of continuous-wave Raman silicon lasers with different parameters is performed. Based on power propagation equations in SOI waveguides and boundary conditions, the output powers as functions of the launched pump power, the gain length, the reflectivity of the output end, and the effective mode area of the SOI waveguide are presented. It is shown that two-photon absorption (TPA) and free-carrier absorption (FCA) lead to a significant reduction to the output power of continuous-wave Raman silicon lasers, which is in good agreement with the experimental reports. Numerical analysis predicts that in the absence of TPA and FCA there are optimum values for the silicon waveguide length, the effective mode area and the output reflectivity, respectively.

In this paper, we demonstrate the output characteristics of a kind of all-fiber optical source based on Er 3+ /Yb 3+ co-doped double-clad fiber (EY-DCF) in a master oscillator-power amplifier (MOPA) configuration. The amplifier is composed of a 10m long EYDCF, two isolators at both input and output terminals, and a 976nm pump diode connecting with the EYDCF via a side-pump fiber coupler. A DFB diode laser operating at 1547.8nm serves as the master oscillator. A maximum output power of 1.16W is obtained. The gain of the fiber amplifiers is up to 30.7dB. The wavelength centered at 1547.8nm with a spectral width no more than 0.02nm shows longtime stability.

As the development of the mobile Internet, especially 3G network technology, rapid dissemination of information, the proliferation of adult data becomes more quickly. Adult images' filtering is the new requirement on the mobile device. Taking into account the difference between mobile devices and the traditional PC, there is a certain lack of calculation power in the mobile devices. Meanwhile the complex calculation will affect the endurance. Through the selection of image features and the appropriate filtering algorithms, we can get an algorithm for filtering adult image with some calculation complexity, In order to validate the algorithm. We did an experiment on the sample set of images fitting the mobile device. The results showed that the more features selected, the better the filtering algorithm. When the four features discussed were selected, the effect of the basic algorithm would achieve an acceptable state. This series of work prepares for the healthy environment of the coming era of mobile networks.