The Research On Auto-pressured Control For Medical Splints

1.IntroductionThe biomedicine survey and its instrument are the important tool for the humanity knows the biological phenomena. The biomedicine development depends on the biomedicine survey technology and the instrument progress, simultaneously unceasingly proposes the massive new topics for the biomedicine survey research. The modern science and technology's many domains progress and the achievement, often first be used for the biomedicine survey technology, has provided the condition for the biomedicine survey technology and the instrument development.Because the biomedicine metering equipment is the human body diseaseinspects, the diagnosis and the treatment main tool, therefore it becomes the most important medical equipment, its product already occupies the main share in the medical equipment product type and the output value, the biomedicine survey technology and the instrument research and the development, is unfolding the extremely bright prospect, is filling the opportunity and the challenge, is one of the most attract development domains in the humanity science and technology .The research and the development of biomedicine survey technology and instrument in bone traumatology department domain is also similarly has the vital significance. The bone fracture is the injury which in the daily life and the work frequently meets, in the cooperation of Chinese and Western medicine treatment four limbs closed bonefracture, the small clamping plank is fixed is treats the bonefracture one commonly used method. The effect is reliable, the bonefracture heals quickly, the function restores, the treatment expense lowly, the patient pain are few and so on many merits. But the small splints fixed application always has a problem, the degree of tightness adjustment all depending on doctor's experienceand feel, about moves 1 centimeter degree of tightness to be appropriate for the pine. tighten the bandage too hard has been able to cause the bone syndrome,even creates seriously is disabled; tighten the bandage too loose has been lost the fixed effect,causes the replacement bone fracture shifting. Therefore only depends on doctor's subjective impression, its resultinevitably causes the degree of tightness difference,affects the bone fracture to fix and to heal, even is easy to createthe serious illness complication.Has designed one kind of medical auto-pressured control small splints view ofabove question this article, this design take thesemiconductor electrostatic capacity type pressure transmitter, thesufficient release equipment, the supply voltage threshold valueexamination electric circuit, the PIC16LF873 micro controller as thecore, realizes each kind of system function. The system in aspect andso on volume, structure, examination method and control method has allmade the improvement and the innovation, mainly displays in:(1) Uses the battery power supply and the miniature sufficient releaseequipment, to the patient and doctor the security, is easy to carry.(2) uses the integrated chip to take the system examination and thecontrol core component, effectively enhances the system thereliability.(3) uses has the sleep pattern the low power loss controller,lengthens the power source single period of revolution.(4) The signal survey unit uses the semiconductor electrostaticcapacity type pressure transmitter, the survey scope broadly,measuring accuracy high, output signal processing electric circuitsimple, the signal parameter is easy to survey.(5) optimum value may initialize, the real time display aerocystintensity of pressure value, the automatic control bone fracture placepressure value nearby the optimum value, reduces doctor the work load,avoids person's subjective factor disturbance pressure valueadjustment.(6) When the supply voltage is lower than the threshold value voltage, triggers the processor to enter the severance, carries on theacousto-optics to report to the police. This time the power sourcealso can work, for replaces the battery to remain has the sufficienttime.(7) most superior pressure value may act according to the differentpatient's situation, establishes in advance, when installs theautomatic control in advance supposes the pressure value withdifficulty, produces reports to the police, reminds the patient toreplace the installment.(8) uses two bodies separation formulas structure.2. Research contentThis article main research content is the development medicalauto-pressured control small splints the automatic pressure controlsystem, realizes body surface pressure signal accurate gathering,between the board the pressure real time display and the automaticcontrol. The main work is the medical auto-pressured control small splints control system of survey hardware design and the softwaredesign.Medical auto-pressured control small splints observation and controlsystem hardware design, including signal processing circuit design,condition initialization and data display circuit design, powercircuit and voltage monitor circuit design, alarm circuit design, automatic presssure control actuation circuit design. System MCU usesPIC16LF873, it has the integration rate very high, the power loss low,the driving force strong, the severance rich, the procedure secrecy isstrong, may on-line characteristic and so on debugging and on-lineprogramming. Internal integrated in the electricity replacement electric circuit,the I/O pin has pulled the electric circuit, WDT the timer andso on, was allowed the greatest degree reduction or exempts withoutside meets the component, not only facilitated to the development,moreover also might save the user the electric circuit board space andthe production cost. The pressure transmitter uses the outsidediameter only to have 16mm, plastic seal semiconductor electrostaticcapacity pressure transmitter SEN301, it has the price lowly, the useis simple, does not need the expensive A/D switch to be able toachieve characteristic and so on very high resolution, definitely maysatisfy the technical specification request which this design needs.The electrical power system uses four 1.5V general dry cell batterypower supply, even if has leaks the electric current also below thepermissible value, cannot cause the damage. Because the sensor, andthe PIC16LF873 monolithic integrated circuit uses the 3.3V voltagepower supply, simultaneously considered the battery the capacity andthe specification, like this, 6V to the 3.3V DC-DC transfer network isthe electrical power system design key, uses TPS76833Q to fall pressesthe DC-DC converter, solves this problem. At the same time, in order to guarantee the system normal reliablework, must carry on the surveillance to the battery voltage, forms thebattery active status signal by the voltage surveillance comparatorelectric circuit, severance carries on the recognition by PIC16LF873the monolithic integrated circuit RB0, realizes the alarm function. For practical application convenient, has specially designedthe pressed key electric circuit, increased the man-machineinteractive ability, expanded the instrument function, simultaneouslycauses the instrument the use to be more convenient quickly with thehuman nature. The data display are partial the duty with the alarmcircuit which mainly needs to complete is the real-time monitorsampling signal, demonstrated when and the surveillance survey datasize, and surpasses the value in the sampling which establishes inadvance, produces the acousto-optics alarm immediately. UsesThe dexterous dull thin film liquid-crystal display EDM1190A module tocarry on the value to demonstrate that, uses the light emitter diodeto carry on the light to report to the police, uses the music chip tocarry on the sound to report to the police. The air pump uses theminiature air pump, releases the air valve to use the exquisiteelectron to be possible to move releases the air valve, overall systemconstitution volume small, the weight is light, facilitates carries.The software design mainly includes: The system monitor routinedesign, the data acquisition programming, the initializationsubroutine and the demonstration programming, reports to the police programming, falls the electricity processingsubroutine design, the digital filter subroutine design, the surveyvalue data processing subroutine design, the system WDT realization and all that some general subroutines. The PIC16LF873micro controller through the system monitor routine, the dataacquisition subroutine, the initialization subroutine, thedemonstration character procedure, reports to the police the characterprocedure, falls the electricity processing subroutine, the digitalfilter subroutine, the survey value data processing subroutine and allthat some general subroutines to the signal examination module, thedemonstration module, the control module, the power sourcesurveillance module carries on the control, the realization systemsignal examination, the data display, auto-pressured control and falls alarm and so on the function. All procedures use the C language compilation, the process modulationdesign, has guaranteed the survey control process timeliness. Insystem monitor routine important solution system initialization,question and so on system self-checking and survey, in order toenhance the system the measuring accuracy and the accuracy, hasdesigned the software numeral filter, the data length is 64, dividesinto 8 groups, in each group designed 8 to hit the mark the valuefilter, 8 center values filters output data realization running meanalgorithm, effectively has overcome the system error, sharpened thesystem antijamming ability.3.ConclusionsThe experiment indicated the medical auto-pressured control small splints the pressure examination precision may reach 1%, the pressure control precision may Reaches 3%. Can complete of pressure between the clamping plankand the body surface tendency real-time monitoring, the operation simple, safe, is reliable, greatly facilitates doctor's work, has avoided because outside the clamping plank fixes not the good consequence which produces. At the same time, themedicalauto-pressured control small splints also has provided the model regarding thebody surface pressure signal examination method for each kind of surface pressure examination.