ABSTRACT
Objective Based on the existing clinical drainage device, two novel mechanisms were designed for the connection between the drainage tube of the patient and the drainage tube of the drainage bag, so as to compare such two mechanisms and validate whether the mechanisms can meet the design requirements for clinical use. Methods Mechanism 1 used the method of electromagnetic drive to pull in and Mechanism 2 used the magnetization method of permanent magnet to pull in. The finite element model of static electromagnetic field was established. The force of the two mechanisms under different currents was compared, and the distribution of magnetic field lines and magnetic induction intensity was analyzed. Simulation experiments were designed for preliminary experimental research. Results Under the pull-in state, the maximum magnetic induction of Mechanism 1 and Mechanism 2 at the closed end surface was found in contact area of the two iron cores. The suction force of Mechanism 1 could be adjusted by the current. When the current was 1 A, the maximum magnetic induction intensity at the closed end was 0.76 T, the electromagnetic force measured by the experiment was 6.08 N, the magnetic force of Mechanism 2 was 6.68 N, which was smaller than the 8 N suture tension. Mechanism 2 was separated by supplying the driving coil with a reverse magnetic field. Conclusions When the current was 1 A, Mechanism 1 could meet the magnetic attraction requirements, and Mechanism 2 could be separated when the current reached 1.8 A. Both mechanisms met the requirements of clinical design, but Mechanism 2 was more secure in the process of application. The feasibility of the mechanism structure was verified by finite element analysis and experimental test.
ABSTRACT
Clinically, routine urinalysis includes more than 10 items, such as urine protein, urinary pH, urinary bilirubin and so on. The above items are usually analyzed by dry chemical methods. The principle is that after the urine infiltrates the reagent strips, the color changes can be observed in each strip. The color depth is related to the component concentration, and the darker the color, the greater the measured component concentration, and vice versa. In this paper, four color discrimination methods in urinary dry chemical analysis were introduced, i.e. the method based on integrating sphere photoelectric conversion, the method based on charge-coupled device (CCD) image sensor, the method based on color sensor, and the method based on the combination of color sensor and fiber bundle. Besides, the four methods were compared and analyzed. Finally, the recent research progress in urinalysis was reviewed.
ABSTRACT
The flushing pump which is applied to clean operative wound has no temperature controlling function up to now, and doctors have to prepare the flushing fluid that has previously been warmed. The flushing pump system with medical constant temperature designed in our laboratory can absorb flushing fluid at the room temperature, and then eject flushing fluid with the temperature in accordance with the requirements of operations at a controlled constant flow rate. The system combines flow rate control with temperature control functions. The flushing pump system includes flushing part, temperature controlling part, key inputting part, liquid crystal displaying part and exceptional situation monitoring part. The present paper introduces the design method and principle of each part of the system at first, and then gives the debug method of all the system parameters. Finally the paper discusses the performance of the system according to the result of the experiment.
Subject(s)
Equipment Design , Equipment and Supplies , TemperatureABSTRACT
In surgery operations, wound should be cleaned with warm sterilized saline solution. In order to reach rapidly warming the washing solution from the room temperature during the surgery, we designed a thermostatic medical infusion pump. The present paper mainly presents researches on the two temperature control methods in the standby mode and in the flushing mode of the system. In the standby mode, the traditional proportional-integral-derivative (PID) control algorithm was adopted. In the flushing mode, dynamic characteristics of the system was changed in real time, which made the thermostatic control process more complex, and the fitted control function combined with the PID control algorithm was adopted in this mode. The temperature control parameters were adjusted in real time according to the initial temperature and the flow rate of the washing solution to obtain a constant temperature of the washing solution, no matter how the initial temperature and the flow rate are changed. The experiment results showed that this kind of control system performed well with a high accuracy.
Subject(s)
Algorithms , Equipment Design , Infusion Pumps , Sodium Chloride , Solutions , TemperatureABSTRACT
This paper presents the preliminary design of data acquisition system of a portable uroflowmeter. The system uses double-hole cantilever pressure sensor. The signal is transferred to ATmega644PA microprogrammed control unit (MCU), converted by A/D (analog to digital) convertor. Then the further data are processed and get the corresponding relationship of weight-time and two curves of urine flow and urinary flow rate. In the measurement accuracy of the device about urine flow, two factors about the placement and height of the data acquisition are analyzed to show the accuracy of the equipment through the Origin 8.0 data analysis software. The design is characterized by low cost and high speed of data collection, real-time, high accuracy.
Subject(s)
Humans , Data Collection , Flowmeters , Monitoring, Ambulatory , Software , Urination , Physiology , Urodynamics , PhysiologyABSTRACT
Aims: To give researches on gastric interdigestive pressure activity, including gastrointestinal (GI) physiological motility recording method, data processing and analysis method, as well as to give reasonable interpretation on how to generate such gastric pressure activity. Study design: Basic application study. Place and Duration of Study: School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology (USST), between June 2010 and October 2011. Methodology: We introduced a telemetric method to get the gastric physiological pressure activity inside the GI tract and the general process for processing such gastric Migrating Motor Complex (MMC) pressure activity including the process of abnormal value removing, medians of five-three-Hanning (53H) weighted average smoothing, and the fluctuation frequency estimation. Results: Using the process of abnormal value removing, medians of five-three-Hanning (53H) weighted average smoothing, and the fluctuation frequency estimation, we well obtained gastric interdigestive pressure activity (MMC). Conclusion: The methods introduced in the paper including abnormal value removing, the 53H weighted average smoothing, and the fluctuation frequency estimation were helpful for researches on gastric interdigestive pressure activity.
ABSTRACT
Using the method of detrended fluctuation analysis (DFA) and power spectral analysis (PSA), the paper deals with the characteristics of long-range correlations of colonic pressure activities and their surrogate data of healthy subjects. The DFA is a period representation of such correlations, whereas the PSA is a frequency representation. The analysis of the two methods consistently shows that there are long memories in colonic pressure activities and there exist long-range correlations, whereas there are no such long memories and long-range correlations in the surrogate data, whose sequential orders are randomly shuffled. The results to some extent indicate that human colonic pressure activities with normal motilities do have long memories, but these memories may be weaker or may even be destroyed with dysmotilities.