Biomedical subjects

Haishu Ding

Publications and source records attributed to Haishu Ding.

5 recordsLinked to original sources

PubMed2005

[A study of gait recognition based on kinematics and kinetics parameters].

In order to recognize people by their gait, we propose a pattern recognizing method based on kinematics and kinetics parameters. The feature extraction methods of joint angle and vertical ground reaction force (VGRF) were given. 14 healthy male subjects participated in this experiment. The experimental results showed that the correct classification rates (CCR) was 87.1% at k = 1 and 90% at k = 3 (k-nearest neighbor) based on joint angle recognition; the CCR was 85.7% at k = 1 and 80% at k = 3 based on VGRF recognition. The multivariate analysis of the experimental data proved the feasibility of gait recognition. The principal component analysis and curves of VGRF also showed that the instant of foot strike plays an important role in gait recognition.

Adult↗

PubMed2005

[The frequency features and application of edge detection differential operators in medical image].

Edge detection is an absolutely necessary step in medical image processing, and the use of differential operators to detect edge is one of the most common and effective methods. In this paper are analyzed the frequency features of the Roberts operator, Prewitt operator, Sobel operator and Laplacian operator from the viewpoint of frequency domain, and it is proposed that the frequency features of the differential operators should be considered when differential operator is being used and/or constructed. Because edge detection operator is sensitive to the edge type, the appropriate operator should be adopted in different edge type detection. Finally, the importance and necessity of selecting edge detection operator are validated in the MRI image edge processing.

Algorithms↗

PubMed2005

[Algorithm for recognizing the markers in human motion detection].

An algorithm for recognizing the markers in human motion detection is proposed in this paper. It includes three parts as follows: (1) an improved template matching method is used to acuminate the peak of the matching result. (2) The weighted average of the cross correlation between target image and template is given in order to make the resolution increase to sub-pixel level. (3) Forecasting the motion of marker and overcoming the hiding of marker are realized basing on the continuity of human motion. The result of experiments shows that the algorithm can recognize the positions of the markers at a relatively higher accuracy and speed. A gait analysis system based on this algorithm has come into use.

Algorithms↗

PubMed2004

Assessment of the hypoxic-ischemic encephalopathy in neonates using non-invasive near-infrared spectroscopy.

This paper introduces a method of monitoring cerebral oxygenation for healthy neonates and neonates with hypoxic-ischemic encephalopathy (HIE) using near-infrared spectroscopy. The object of this study was to investigate whether or not there were differences between the HIE group and the healthy group in terms of NIRS parameters. The subjects were all term neonates, their age ranging from 2 to 18 days. The healthy group included 25 subjects while the HIE group consisted of 16 patients. A prototype NIRS instrument, which provides the data of tissue oxygenation including regional oxygen saturation (rSO2), the increment of oxyhemoglobin concentration and hemoglobin (deltaHbO2 and deltaHb) was used, and the data of rSO2 was compared with the data from the blood gas analyzer. The result shows that: (1) the mean+/-SD of rSO2 for the healthy group was 62 +/- 4% in the frontal region under the quiet sleep condition, but the mean+/-SD of rSO2 for the HIE group was 53 +/- 3%. (2) As all subjects inhaled pure oxygen in 21 min(-1) for a period of 60 s, rSO2 for the healthy group increased rapidly, with the increase in rSO2 (deltarSO2) being 7 +/- 2.3%, but the increase in rSO2 for the HIE neonates was 3 +/- 1.5%. After inhaling oxygen, deltaHbO2 and deltaHb between the two groups were also significantly different. (3) During all the experiments SpO2 was monitored, the value of SpO2 was not significantly different between the two groups. The above observations suggest that the rSO2 in quiet condition and the values of change of rSO2, HbO2 and Hb during the inhalation of oxygen may be used as the parameters to discover and assess the HIE infants.

Algorithms↗

PubMedDate not supplied

Monitoring cerebral oxygen saturation during cardiopulmonary bypass using near-infrared spectroscopy: the relationships with body temperature and perfusion rate.

During cardiopulmonary bypass (CPB) because of weak arterial pulsation, near-IR spectroscopy (NIRS) is almost the only available method to monitor cerebral oxygenation noninvasively. Our group develops a NIRS oximeter to monitor regional cerebral oxygenation especially its oxygen saturation (rScO2). To achieve optimal coupling between the sensor and human brain, the distances between the light source and the detectors on it are properly chosen. The oximeter is calibrated by blood gas analysis, and the results indicate that its algorithm is little influenced by either background absorption or overlying tissue. We used it to measure the rScO2 of 15 patients during CPB. It is shown that rScO2 is negatively correlated with body temperature and positively with perfusion rate. There are two critical stages during CPB when rScO2 might be relatively low: one is the low-perfusion-rate stage, the other is the early rewarming stage. During cooling, the changes of total hemoglobin concentration (C(tHb)) compared with its original value is also monitored. It is shown that C(tHb) decreases to a small extent, which may mainly reflect cerebral vasoconstriction induced by cooling. All these results indicate that NIRS can be used to monitor cerebral oxygenation to protect cerebral tissue during CPB.

Adolescent↗