Development And Application Of A New Generation Multi-channel Series Piezoelectric Quartz Crystal Blood Culture Systems

Microbial infectious diseases,with a high incidence and mortality,is one of the main cause of human death.Pathogen detection is the main basis for the diagnosis of infectious diseases."Blood culture" is the "gold standard" for the detection of bacteria and fungi by clinical microbiological laboratories.At present,clinical automated blood culture systems such as BACTEC and BacT/Alert have achieved rapid and accurate detection of clinical microorganisms.However,these systems rely solely on changes in CO2 concentration to generate signal,and it is hard to detect non-fermentative bacteria that produce less gas but much acid.Furthermore,the increase in CO2 caused by non-bacterial factors can lead to false positive results,and radioactive contamination exist in part of the BACTEC system.In addition,expensive instruments and reagents increase the burden on patients,thus limiting its universal application especially in poor areas with high incidence of infectious diseases.The development of the automated blood culture system with excellent performance and lower cost,is not only the expectations of patients and health care workers,but also the relentless pursuit of medical device developers.Multi-channel series piezoelectric crystal sensor can be sensitive to the changes of electrical parameters.With the property of high sensitivity,good reproducibility,easy operation and low cost,it has been applied to detect clinical microbial.In order to meet the evolving clinical needs and solve the remaining problems in the MSPQC clinical application,this paper based on the related work results is devoted to research and construct a new generation of multi-channel series piezoelectric crystal sensing blood culture system.The work carried out is as follows:(1)Debugging of the new generation of multi-channel series piezoelectric crystal sensing blood culture system and development the new criterion.The new generation of multi-channel series piezoelectric blood culture crystal sensing system is construct using the controller local area network(CAN)technology.And the number of sample channel is successfully increased to 64.Debugging is the necessary procedures to ensure the normal work of a new equipment.By repeated debugging of the various modules,the system problems is repaired,and the normal operation of the system functions is guaranteed.Besides that the sample database is constructed and the MATLAB tools is used to optimize algorithms for data interpretation.The new criterion utilizing the frequency shift condition and the DoseResp fitting parameter condition realized the accurate interpretation of the test result.(2)Application evaluation of the new generation multi-channel series piezo-electric crystal sensing blood culture system.The new generation of MSPQC blood culture system and the antibiotic neutralization bottle developed by our group at this stage were evaluated clinically.The accuracy rate of the new MSPQC blood culture system was 98.8%.The detection rate of the positive sample was 98.3%,and the detection time was almost within 24 hours.Among them,the detection of fastidious bacteria was the most slowly.The positive detection time of the new generation of MSPQC blood culture system was significantly earlier than that of the previous generation one,and that was no significant difference with BACTEC FX200 system and BacT/Alert 3D system.Due to the less blood collection,MSPQC XPY-064 is not superior than BACTEC FX200 for testing clinical sample.Antibiotic neutralization bottle successfully achieved the detection of microbial in the simulated samples contains therapeutic levels of antibiotics.Overall,for the effect of detecting microbe,activated carbon bottles is better than resin composite bottles.But the adsorption effect of activated carbon for gentamicin,tetracycline,ciprofloxacin and clindamycin is poor than the resin bottles,yet to be further improved.(3)Performance optimization of multi-channel series piezoelectric crystal sensing blood culture system.For the deficiency of multi-channel series piezoelectric blood culture system in the clinical application,such as the small mount appropriate blood collection and the lagging detection of fastidious bacteria,the third work of this paper researched the response performance of different conductive electrodes series piezoelectric sensor on the changes of the solution conductivity.Disk electrode series piezoelectric sensor whose frequency shift response is the most sensitive,has much stronger ability than the conductivity meter for response the conductivity change of solution.And in a certain range,its sensitive is almost the same as the precision impedance analyzer.The piezoelectric sensor in series with the disk electrode has successfully realized the detection of microorganisms in the medium with large conductivity.The limitation of the conductivity range of the medium is no longer harsh,which provide a new possibility for the development of a variety of new media.The microbial detection under large amount of blood collection expand the applicability of MSPQC blood culture system from only children patients to all ages.