1.Development and application of a fundus transverse microscopic imaging system.
Yunhai ZHANG ; Saisai NIU ; Jiliang ZHU ; Yanwen JIA
Chinese Journal of Medical Instrumentation 2011;35(1):24-27
A human fundus transverse microscopic imaging system based on a MEMS deformable membrane mirror was developed. A 37 element small MEMS deformable membrane mirror was used as wave front corrector in this system. Wavefront errors were measured by a Hartman-Shack wave front sensor which contains 127 micro lens lets. After the wavefront error of human eye had been corrected by the deformable membrane mirror under the control of a computer, the imaging illumination light was triggered by a electronic shutter to illuminate the retina, the images were captured by a CCD camera. It has been showed in model eye's test that the system could measure and correct the eye's wavefront aberration efficiently. The fundus image achieved the diffraction limit after aberration correction. It was showed in clinic that except a few patients with turbid eye, most patients could finish the process of measuring and correcting wavefront aberration and then taking fundus image. The examination process could be finished safely, quickly and reliably.
Diagnostic Imaging
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instrumentation
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methods
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Equipment Design
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Fundus Oculi
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Humans
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Lighting
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Microcomputers
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Ophthalmoscopes
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Photomicrography
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instrumentation
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methods
2.Development and clinical application of the tractor for the fracture reduction.
Guo-jun ZHANG ; Li-min JIA ; Pei-de FEN ; Lian-gen WU ; Hui-jun ZHANG
Chinese Journal of Medical Instrumentation 2002;26(4):275-278
This paper expounds how the tractor for the fracture reduction works. The clinical results show that the traction apparatus is a labour-saving and time-saving orthopedic device with simple operation and few suffering to patients.
Arm Injuries
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diagnostic imaging
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surgery
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Equipment Design
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Fracture Fixation
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instrumentation
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methods
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Fractures, Bone
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diagnostic imaging
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surgery
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Humans
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Leg Injuries
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diagnostic imaging
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surgery
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Radiography
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Traction
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instrumentation
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methods
3.The nuclear stethoscope in China.
Chinese Medical Sciences Journal 2009;24(1):1-2
4.High-frequency ultrasound (HFUS) and its biomedical applications.
Chinese Journal of Medical Instrumentation 2005;29(1):1-4
HFUS is ultrasound whose frequency is higher than 10MHz. HFUS imaging features very high resolution, which is up to 20 microm. HFUS is used to check the superficial organs such as eye ball and skin with extremely high resolution. When applied to small animals, HFUS is able to scan the body and the embryo in microscopic scale. The blood flow information in microcirculation can be detected if the high frequency Doppler technology is applied. Convenience, simplicity, real time and high resolution of HFUS have lead to a significant role in biomedical research and clinical applications.
Animals
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Equipment Design
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Eye Diseases
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diagnostic imaging
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Humans
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Image Enhancement
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instrumentation
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methods
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Mice
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Microscopy
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methods
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Rats
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Sensitivity and Specificity
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Skin Diseases
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diagnostic imaging
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Ultrasonography
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instrumentation
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methods
5.A novel validation method based on radial distance error for 3D medical image segmentation.
Journal of Biomedical Engineering 2007;24(4):742-747
3D medical image segmentation is a fundamental technique for computer assisted surgery and therapy. There exist various segmentation algorithms, but still we hope to have a more efficient and intuitive evaluation method for validation. In this paper, after reviewing the existing validation methods, we propose a new approach for 3D image segmentation validation. The details of the method are introduced in two parts: local error validation and global accuracy validation. Then, we apply it to validate three typical segmentation algorithms and a user proposed hybrid segmentation method in our experiment. The hybrid approach is also briefly introduced. The experimental results reveal that the proposed validation method can evaluate the employed segmentation methods more accurately and intuitionally.
Algorithms
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Diagnostic Imaging
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instrumentation
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methods
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Humans
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Image Enhancement
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methods
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Image Interpretation, Computer-Assisted
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methods
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Imaging, Three-Dimensional
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methods
6.New progress on three-dimensional movement measurement analysis of human spine.
Xiao-wen QIU ; Xi-jing HE ; Si-hua HUANG ; Bao-bao LIANG ; Zi-rui YU
China Journal of Orthopaedics and Traumatology 2015;28(5):476-481
Spinal biomechanics, especially the range of spine motion,has close connection with spinal surgery. The change of the range of motion (ROM) is an important indicator of diseases and injuries of spine, and the essential evaluating standards of effect of surgeries and therapies to spine. The analysis of ROM can be dated to the time of the invention of X-ray and even that before it. With the development of science and technology as well as the optimization of various types of calculation methods, diverse measuring methods have emerged, from imaging methods to non-imaging methods, from two-dimensional to three-dimensional, from measuring directly on the X-ray films to calculating automatically by computer. Analysis of ROM has made great progress, but there are some older methods cannot meet the needs of the times and disappear, some classical methods such as X-ray still have vitality. Combining different methods, three dimensions and more vivo spine research are the trend of analysis of ROM. And more and more researchers began to focus on vivo spine research. In this paper, the advantages and disadvantages of the methods utilized recently are presented through viewing recent literatures, providing reference and help for the movement analysis of spine.
Animals
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Humans
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Imaging, Three-Dimensional
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instrumentation
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methods
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trends
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Radiography
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Spine
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diagnostic imaging
7.Shearwave-based ultrasound viscoelasticity measurement system for evaluation of liver fibrosis.
Tan WEI ; Han XIAODONG ; Cheng GANG ; Christopher HAZARD
Chinese Journal of Medical Instrumentation 2010;34(5):330-334
This paper describes a liver elasticity and viscosity measurement system based on existing medical ultrasound platforms. This system relies on acoustic radiation force to invoke transient response on soft tissue, and employs displacement estimation algorithms to detect the propagation of shear wave. The research proves that the velocity of the shear wave may serve as a reliable estimation of the Young's modulus and viscosity coefficient of the liver tissue, and existing commercial products may be easily adapted to support this technique without extra hardware cost.
Algorithms
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Animals
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Elastic Modulus
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Elasticity Imaging Techniques
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instrumentation
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methods
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Liver Cirrhosis
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diagnostic imaging
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Viscosity
8.The setting up of reflectance confocal microscope and its in vivo application in skin tissue imaging.
Xiao-rui FENG ; Peng XI ; Qiu-shi REN
Chinese Journal of Medical Instrumentation 2009;33(6):398-401
This article, introduces setting up of reflectance confocal microscope which is divided into four parts: optical system, scanning system, detecting system and software controlling system. This reflectance confocal microscope realizes in vivo epidermis tissue imaging in mouse skin as well as disease diagnosis related cell parameters measurement.
Animals
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Diagnostic Imaging
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instrumentation
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methods
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Microscopy, Confocal
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methods
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Rats
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Skin
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Software
9.Assessment of parotid gland dose variations by helical tomotherapy adaptive system in head and neck cancer.
Gang REN ; Shouping XU ; Lei DU ; Chuan-bin XIE ; Lin MA
Chinese Journal of Medical Instrumentation 2010;34(5):335-338
The paper introduces a helical tomotherapy (HT) adaptive system in assessment of parotid gland dose variation in head and neck cancer. The system, which helical therapy unit is equipped with, is based on megavoltage computed tomography (MVCT) images to calculate the actual volume and dose of region of interest (ROI). Whether to change plan is judged on the fact for the realization of adaptive radiotherapy. One case of nasopharyngeal carcinoma was as a sample to evaluate parotid gland dose variation during the treatment. On every week and last time, patient was scanned by MVCT before treatment, a total of eight MVCT images. As the treatment progressed, the parotid gland volume was shrinking and the dose was increasing. The parotids volume variation was negatively related with D50 and V1 (both P < 0.05).
Adult
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Head and Neck Neoplasms
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diagnostic imaging
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Humans
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Male
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Parotid Gland
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diagnostic imaging
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Radiotherapy Dosage
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Radiotherapy Planning, Computer-Assisted
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instrumentation
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methods
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Software
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Tomography, Spiral Computed
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instrumentation
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methods
10.Laser-induced interstitial thermotherapy via a single-needle delivery system: Optimal conditions of ablation, pathological and ultrasonic changes.
Yan-Rong ZHANG ; Ling-Yun FANG ; Cheng YU ; Zhen-Xing SUN ; Yan HUANG ; Juan CHEN ; Tao GUO ; Fei-Xiang XIANG ; Jing WANG ; Cheng-Fa LU ; Tian-Wei YAN ; Qing LV ; Ming-Xing XIE
Journal of Huazhong University of Science and Technology (Medical Sciences) 2015;35(4):579-584
This study aimed to examine the optimal conditions of laser-induced interstitial thermotherapy (LITT) via a single-needle delivery system, and the ablation-related pathological and ultrasonic changes. Ultrasound (US)-guided LITT (EchoLaser system) was performed at the output power of 2-4 Wattage (W) for 1-10 min in ex vivo bovine liver. Based on the results of the ex vivo study, the output power of 3 and 4 W with different durations was applied to in vivo rabbit livers (n=24), and VX2 tumors implanted in the hind limbs of rabbits (n=24). The ablation area was histologically determined by hematoxylin-eosin (HE) staining. Traditional US and contrast enhanced ultrasound (CEUS) were used to evaluate the treatment outcomes. The results showed: (1) In the bovine liver, ablation disruption was grossly seen, including a strip-like ablation crater, a carbonization zone anteriorly along the fiber tip, and a surrounding gray-white coagulation zone. The coagulation area, 1.2 cm in length and 1.0 cm in width, was formed in the bovine liver subjected to the ablation at 3 W for 5 min and 4 W for 4 min, and it extended slightly with the ablation time. (2) In the rabbit liver, after LITT at 3 W for 3 min and more, the coagulation area with length greater than or equal to 1.2 cm, and width greater than or equal to 1.0 cm, was found. Similar coagulation area was seen in the implanted VX2 carcinoma at 3 W for 5 min. (3) Gross examination of the liver and carcinoma showed three distinct regions: ablation crater/carbonization, coagulation and congestion distributed from the center outwards. (4) Microscopy revealed four zones after LITT, including ablation crater/carbonization, coagulation, edema and congestion from the center outwards. A large area with coagulative necrosis was observed around a vessel in the peripheral area with edema and hyperemia. (5) The size of coagulation was consistent well to the CEUS findings. It was concluded that EchoLaser system at low power can produce a coagulation area larger than 1.0 cm×1.0 cm during a short time period. The real-time US imaging can be used to effectively guide and assess the treatment.
Animals
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Bone Neoplasms
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diagnostic imaging
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pathology
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therapy
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Cattle
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Hindlimb
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pathology
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Laser Therapy
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instrumentation
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methods
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Liver Diseases
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diagnostic imaging
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therapy
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Rabbits
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Treatment Outcome
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Ultrasonic Therapy
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instrumentation
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methods
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Ultrasonography