The content related to the quality during life-cycle in operation of medical device includes daily use, repair volume, preventive maintenance, quality control and adverse event monitoring. In view of this, the article aims at discussion on the quality evaluation method of medical devices during their life cycle in operation based on the Analytic Hierarchy Process (AHP). The presented method is proved to be effective by evaluating patient monitors as example. The method presented in can promote and guide the device quality control work, and it can provide valuable inputs to decisions about purchase of new device.
Decision Support Techniques ; Durable Medical Equipment ; standards ; Equipment Design ; Quality Control

OBJECTIVETo introduce algorithms for effective segmentation of teeth MRI-UTE image.

METHODSTo construct second-segmentation algorithm process based on layer-dependent multi-constrained method. Firstly, a level set method was used to segment the initial boundary from the region determined by user in the reference slice. Secondly, both crown and root of the tooth were segmented by the improved level set method which took the information of the former layer's result as constraint conditions. Finally, the improved level set based on the information of the former and later layer's results was executed for the second time to improve the accuracy of segmentation, in which, the parameter of the overlapping ratio was considered.

RESULTSThe accuracy was 86.98% for the first-segmentation and was increased to 88.35% for the second-segmentation. Compared to the two other methods, the accuracy of the algorithms provided was improved significantly (P < 0.05).

CONCLUSIONSThe proposed algorithms can effectively achieve the segmentation of teeth MRI-UTE image and has a great improvement on accuracy.

Algorithms ; Humans ; Image Enhancement ; Magnetic Resonance Imaging ; methods ; Orthodontics, Corrective ; methods ; Tooth ; anatomy & histology

OBJECTIVETo segment veins from brain susceptibility weighted images with inhomogeneous background and veins, noises and complex structures.

METHODSBased on vessel enhancing filtering, an adaptive threshold segmenting method and an adaptive threshold region growing method were proposed. The former method was used to exactly segment part of veins from the original images. Taking the veins segmented by the former method as seeds, the later method was used to extract nearly all the veins.

RESULTSFor simulation data with serious noises and interferences, correct rate above 90% was achieved. And for clinical data, the veins were extracted accurately and the structures of veins were displayed clearly.

CONCLUSIONSThe methods can extract veins from the brain susceptibility weighted images exactly and avoid false segmentation of the other structures effectively. The methods are very robust and stable.

Cranial Sinuses ; anatomy & histology ; Humans ; Image Enhancement ; Magnetic Resonance Imaging ; methods

Objective The article aims at survey and analysis on ventilator alarm status in pediatric hospital. Methods First,we design the statistical table of ventilator, and analyze the reliability of statistical table. Then we evaluate the effectiveness of the alarm. Finally, we evaluate the alarm information synthetically through investigation and statistics.Results The ventilator alarm is ineffective, a large number of nonsensical alarms, leading to lower alert sensitivity of medical staff. Conclusion According to the survey results, we should analyze the cause of the problem, and propose the corresponding alarm management method.

Objective To segment veins from brain susceptibility weighted images with inhomogeneous background and veins, noises and complex structures. Methods Based on vessel enhancing filtering, an adaptive threshold segmenting method and an adaptive threshold region growing method were proposed. The former method was used to exactly segment part of veins from the original images. Taking the veins segmented by the former method as seeds, the later method was used to extract nearly al the veins. Results For simulation data with serious noises and interferences, correct rate above 90% was achieved. And for clinical data, the veins were extracted accurately and the structures of veins were displayed clearly. Conclusions The methods can extract veins from the brain susceptibility weighted images exactly and avoid false segmentation of the other structures effectively. The methods are very robust and stable.

Objective To introduce algorithms for effective segmentation of teeth MRI-UTE image. Methods To contruct second-segmentation algorithm process based on layer-dependent multi-constrained method. Firstly, a level set method was used to segment the initial boundary from the region determined by user in the reference slice. Secondly, both crown and root of the tooth were segmented by the improved level set method which took the information of the former layer's result as constraint conditions. Final y, the improved level set based on the information of the former and later layer’s results was executed for the second time to improve the accuracy of segmentation, in which, the parameter of the overlapping ratio was considered. Results The accuracy was 86.98% for the first-segmentation and was increased to 88.35% for the second-segmentation. Compared to the two other methods, the accuracy of the algorithms provided was improved significantly (P<0.05). Conclusions The proposed algorithms can effectively achieve the segmentation of teeth MRI-UTE image and has a great improvement on accuracy.

Objective To establish an optimal limiting dose for dose limiting rings placed in the anterior and posterior regions of the neck for reducing head and neck lymphedema under intensity-modulated radiation therapy(IMRT)for early nasopharyngeal carcinoma(NPC)from a dosimetric perspective.Method Fifteen newly diagnosed early-stage nasopharyngeal carcinoma patients who underwent CT localization for radiotherapy at the Cancer Hospital of Guangzhou Medical University from January to September 2022 were included in the study.Each case was designed with five sets of radiotherapy plans.Plan A consisted of conventional unlimited-field plans,while Plans B-E consisted of limited-field plans with dose constraints set at 20,18,16,and 14 Gy,respectively,with the remaining parameters consistent with Plan A.The impact on target coverage and organ-at-risk constraints was evaluated through variance analysis and pairwise multiple comparisons using a randomized block design to determine the optimal dose limits.Results The gradient of 16Gy was determined as the optimal dose limiting cutoff point for achieving the balance between target coverage and organ limiting dose.Compared with the conventional plan,The plans with the placement of a cervical anterior and posterior dose limiting ring(16Gy)did not change the target dose coverage(P>0.05),but only yielded a slight change in the homogeneity index(P<0.05).It did not cause any changes of the dosage in the inner ear,mandible,and brainstem(all P>0.05),but lead to statisti-cally significant reductions in the oral cavity,throat,and thyroid(all P<0.05).It caused a slight increase of the dose in the parotid gland and spinal cord(both P<0.05),but the increased dose was anyhow within the tolerance range.Conclusion The dosimetric investigation determines an optimal dose limit cutoff point for the cervical ante-rior and posterior dose limiting rings.It is expected to provide a design method for IMRT plans to reduce head and neck lymphedema after radiotherapy for early NPC.

Objective:To explore the differences in the clinical application of different brands of infrared ear thermometers in pediatric patients,and to guide the rational use of infrared ear thermometers.Methods:A total of 164 inpatients and outpatients who received treatment in the Children's Hospital of Zhejiang University School of Medicine from May 2023 to July 2023 were randomly selected,and three different brands of ear thermometers were used to measure the ear temperature of the children in the same measurement method.The differences in temperature and time measured by different brands of ear thermometers in children of different ages were compared.Results:The temperature and time measurements of the three ear thermometers were compared,the difference was statistically significant(F=5.007,264.988,P<0.05).The temperature of children aged≤3 months was measured by the three ear thermometers,and the difference was statistically significant(F=3.868,P<0.05).there was no difference in children aged over 3 months.Conclusion:For children of different ages,medical institutions can make choices based on the comprehensive consideration of the use cost,the speed of measurement time and other factors.For children aged over 3 months,choose product B with lower cost and faster measurement time,for children aged 0-3 months,it is recommended to choose product A with more accurate temperature measurement values.

Based on the Kraljic model,this paper established the scoring standard system for medical equipment procurement,and determined the weight coefficients of each evaluation factor by the analytic hierarchy process (AHP),then the procurement classification model of medical equipment was successfully established.It is proved that this model can classify medical equipment effectively,which enables the purchasing personnel to adopt corresponding purchasing strategies according to different classification.This model can be extended to all medical equipment procurement,realizing the delicacy and individualized procurement management of the equipment,which has strong operability and guiding significance.
Equipment and Supplies ; economics ; Models, Theoretical