Domain-Specific Cognitive Prosthesis for Face Memory and Recognition.

The present study proposes a cognitive prosthesis device for face memory impairment as a proof-of-concept for the domain-specific cognitive prosthesis. Healthy subjects (n = 6) and a patient with poor face memory were enrolled. An acquaintance face recognition test with and without the use of cognitive prosthesis for face memory impairment, face recognition tests, quality of life, neuropsychological assessments, and machine learning performance of the cognitive prosthesis were followed-up throughout four weeks of real-world device use by the patient. The healthy subjects had an accuracy of 92.38 ± 4.41% and reaction time of 1.27 ± 0.12 s in the initial attempt of the acquaintance face recognition test, which changed to 80.48 ± 6.23% (p = 0.06) and 2.11 ± 0.20 s (p < 0.01) with prosthesis use. The patient had an accuracy of 74.29% and a reaction time of 6.65 s, which improved to 94.29% and 3.28 s with prosthesis use. After four weeks, the patient's unassisted accuracy and reaction time improved to 100% and 1.23 s. Functional MRI study revealed activation of the left superior temporal lobe during face recognition task without prosthesis use and activation of the right precentral motor area with prosthesis use. The prosthesis could improve the patient's performance by bypassing the brain area inefficient for facial recognition and employing the area more efficiently for the cognitive task.

[Development of breath movement reverse tracking system for tumor precision radiotherapy].

OBJECTIVE: To reduce the influence of breathing movement on the location precision of the tumor target in precise radiotherapy for thoraco-abdominal tumors. METHODS: An inverse tracking system was developed to track the path of the breathing movement of the tumor target via image guiding. With this system, the displacement of the target in a given time period was tracked and quickly transformed in signals that drove the tracking couch to move inversely relative to the tumor target. CONCLUSION: This system can effectively reduce the influence of tumor target breath movement during radiotherapy. Compared with other breath movement control methods, this method avoids prolonged exposure time, allows the patient to breathe at ease and shortens the time of CT scanning.

[Development of a water tank for X-ray dose measurement in stereotactic radiotherapy (X-knife)].

This paper presents a novel x-ray dose testing water tank used for the stereotactic radiation therapy system, including its constitution, structure and the method of using it. The water tank has a simple structure of inner and outer sleeves which are connected through a drowned pump and a water pipe in order to control the water level of the tank. The water tank featuring autoregulation and easy use is worthy of clinical application and popularization.

[Genetic algorithm-based dose optimization in intensity modulated radiation therapy].

As a powerful global optimization approach, genetic algorithms (GA) can solve a variety of optimization problems in which the objective function is discontinuous, non-differentiable, or highly non-linear, to produce high convergence speed and vast search space. In this thesis, GA is used to optimize the beam weights of intensity modulated radiation therapy (IMRT) inverse planning, and 2D and 3D isodose contour as well as dose volume histogram (DVH) are used to evaluate the treatment plan. Also presented in this thesis are the results of calculation with discussions.

[A preliminary study of beam weight optimization of intensity-modulated radiation therapy with genetic algorithm].

UNLABELLED: To study the method for dose calculation and beam weight optimization of intensity-modulated radiation therapy (IMRT). METHODS: The IMRT dose calculation model based on two-dimensional convolution was constructed, the program of dose calculation and beam weight optimization with genetic algorithm was written with Visual c#.Net, and the optimization results were analyzed. RESULTS: Genetic algorithm optimization of beam weights can produce highly conformal dose distributions within a clinically acceptable computation time. CONCLUSION: Genetic algorithm is valid and efficient in IMRT beam weight optimization, which may facilitate IMRT treatment planning.

[A new method for static intensity-modulated radiation therapy].

OBJECTIVE: To develop a new method for static intensity-modulated radiation therapy (IMRT) possible for implementation in smaller hospitals by incorporating accurate location equipments and treatment planning system in the available equipments for general radiotherapy. METHODS: Based on the techniques of conformal radiotherapy, a new split method for fabricating the three-dimensional physical compensator was developed to achieve IMRT. RESULTS: Experiment with the new method showed that the fabricated compensator could achieve good match between the high dosage shape in the target area and the dimensions of the tumor, and allowed adjustment of the dosage distribution according to the therapeutic requirement. CONCLUSION: This simple and feasible method allows cost-effect application of IMRT in smaller hospitals.

[Development of a new system for head and neck stereotactic conformal radiotherapy].

This paper introduces the constitution and fabrication of the new head and neck stereotactic conformal radiotherapy system. It remedies the shortages in the head and neck stereotactic conformal radiotherapy at present and it is deserved to be popularized in clinical applications.