LED surgical lights-the latest trend of the shadowless lamp

Shadowless lamp is operating the most important medical equipment, medical staff, through the use of the shadowless lamp in patients undergoing fertilization parts no shadow lighting purposes, to help the doctor clearly distinguished focus tissue, successfully completing the operation.

At present, most of the hospitals in the country are using traditional overall reflection shadowless lamp, with its typically use a halogen light source also commonly known as halogen lamp, but from this year's domestic and foreign major medical equipment exhibition, including Germany, Dusseldorf medical equipment exhibition (Medica) and Beijing International medical equipment fair (China Med), shadowless lamp manufacturers have launched their new flagship LED the shadowless lamp product, the show could hardly find halogen lamp, LED the shadowless lamp replacement halogen lamp has become an irresistible trend.

Relative to the halogen lamp, LED the shadowless lamp uses a new technology platform, it is accompanied by LED technology continues to mature and, now LED by chip design and packaging technology has been able to fully meet the shadowless lamp in illuminance and color index requirements, while LED also has a long life, environmental protection, low energy consumption of benefits, in line with the current hospital overall green lighting requirements, in addition, the spectral distribution of the led light source also determines its ideal as the light source the shadowless lamp operation.

Long service life

Overall reflection shadowless lamp usually use halogen bulb, their average life expectancy is only 1000 hours, more expensive metal halide bulb life is only 3000 hours or so, this makes the overall reflection shadowless lamp bulbs need replacement as consumables.

And LED the shadowless lamp, LED lamp, average service life reach 20000 hours, even days 10 hours, or 8 years of trouble-free use, basic without worrying about the replacement of the lamp.

Green environmental protection

Mercury is a highly polluting heavy metal, 1 mg of mercury to 5000 kg of water pollution, in various specifications of the halogen bulb and metal halide lamp bulb, mercury content from a few milligrams to dozens of mg, coupled with its short life, for a period of time will have a large number of possible and accumulation of serious pollution to the environment of medical waste products to hospitals in post processing than the big bother.

The led bulb of component materials including solid-state semiconductor, epoxy resin and a small amount of metal that is non-toxic, non-polluting materials, in its long after the end of life can also be recycled. In the current environment protection and more emphasis on age, two-phase comparison, LED the shadowless lamp will undoubtedly become the era of the new selection.

Low emissivity low energy consumption, conducive to Postoperative wound recovery

Whether using incandescent light emitting principle of halogen bulb or using high pressure gas discharge principle of metal halide bulb, its luminous process with large amounts of heat, at the same time produce a large volume of infrared and ultraviolet radiation, heat energy and not only increased the unnecessary energy consumption, back surgery has brought many adverse effects.

Cumulative effect of a large number of thermal energy will include light bulb lamp holder within the device's own life, and which would endanger the security of the internal lamp holder. And radiation will arrive with visible light, surgical wounds of a large number of infrared rays cause wound tissue rapid warming and drying, dehydration and damaged tissues and cells; large amounts of UV are direct damage and kill the exposed tissue cells, eventually resulting in postoperative recovery time greatly extended. The LED light principle is to use injected current drive carrier through a combination of p-n junction and the hole and the extra energy to release the energy forms, this is a gentle process, almost all power into visible light, and no excess heat produced, but also in its spectral distribution, only contain a small amount of infrared and ultraviolet radiation, so do not exist will not give the organization in patients with wound damage, cancer doctors won't because head temperature rise too high and discomfort.

At present the domestic manufacturers, due to the technical bottlenecks using LED light source.

It is understood that focus on operating room and ICU total solution of Beijing friendship on company pioneered with led light source, has recently launched a high grade LED the shadowless lamp, may thereafter will lead the domestic operation a new era of lighting.

GE Healthcare and Centrak publishing beds-level real-time locating system

GE Healthcare and Centrak recently published beds-level real-time locating system, this newly developed technology is suitable for hospital medical device tracking mobile needs hospital wants RFID tag position accuracy of medical devices will be able to reach every part of the room.

This Asia room-level recognition capability on certain areas of the hospital is important because it can greatly improve RFID room level positioning accuracy. This new technology called Asset Optimization System (asset location optimization system), makes the Hospital where the exact location of assets, monitoring can be as small as 6 feet x 8 feet, which is a typical small beds district area. Beds in the area can be open or separated by bulian. GE Medical technology company, Bret Barczak said: "our customers tell us that reliable accuracy, price is they select RFID system's two most important factors. Many systems can provide a higher level of location accuracy room, such as ultra-wideband, but often because the price is too high to limit their use. Asset Optimization System allows hospitals to create a virtual room for RFID, there are higher intelligence, tracking and reporting capabilities, very valuable. Particularly in operating theatres and intensive care room such a place. "New York Maimonides Medical Center information Director Kenneth N. Sable said:" we are on the programme of the technology in two impressive progress. First, create a virtual wall, which often open emergency departments environment is very effective. Because it makes it easier for our fast and reliable positioning patients and first aid equipment, such as cardiac pacemakers and portable ultrasonic equipment. Moreover the system is battery-powered, no additional wiring, maintenance is simple. ”

CenTrak company CEO Ari Naim said: "our first RFID system provides 100% of the room-level positioning accuracy.

Now our system of positioning accuracy further improves the leading position in the market. Our goal is to adopt RFID technology to meet the highest visual resolution. Imagine if we can do at the level of visibility, the beds are able to identify who, when and in what we do, the effect will be. ”

Treatment of atrial fibrillation: magnetic resonance imaging to help forecast

Researchers have developed a method based on magnetic resonance imaging of the new therapy for the detection and assessment has undergone a treatment of patients with atrial fibrillation in the left atrium wall.

Atrial fibrillation is a type of abnormal heart rhythm (arrhythmia). Currently effective in the treatment of atrial fibrillation is RF current ablation therapy: a mild painless current PLEI removed carefully selected heart muscle cells to prevent the transmission of these muscle cells stimulated additional ECG.

To date, there is no accurate non-intervention approach can be used to accurately assess the scars left atrium, in charge of research about Nassir F. Marrouche, we have developed a novel method of magnetic resonance technology to detect and assess the scope of the scars of the left atrium and potential to predict RF current ablation is successful.

The study's researchers have developed a technique without intervention, called delay increases cardiovascular magnetic resonance, the technology used by people with atrial fibrillation patients left atrial RF current ablation therapy before and after the creation of 3-dimensional image.

This harm organizations rebuild model can rebuild RF current ablation therapy in RF energy is applied to the relevant area and, therefore, can reflect on the scar tissue. The researchers also found that the left atrium wall surgery damage ratio lower patients more likely to avoid arrhythmia, and recommended that the size of the SCAR and the surgery was successful linkages between.

The new imaging technology and analysis can help physicians improve RF current ablation therapy program, so that he more readily to identify what is needed to remove the heart muscle cells.

And remove the heart muscle cells will likely reduce the recurrence of atrial fibrillation.

The 3-dimensional magnetic resonance benefit lies in the ability to render full left atrium room wall, Marrouche talked about, and he is safe and non-Interventional so it can be repeatedly used on patients without causing significant risks

May monitor the heartbeat, Japan research and development of children action monitoring "braces"

Japan Tsukuba University researchers announced on 12 July to media, they developed the ability to monitor children's daily activities.

Let the child take wearing such as braces like small appliances, guardian can remote real-time confirmation of action for children.

According to reports, this small device installed cameras, global positioning systems, sensor, heartbeat monitors, etc.

On the tape from the armpit, inclined back in the right shoulder on a three-point fixation, colors and shapes, you can choose according to the preferences of the child. The entire unit weighs approximately 100 grams, is almost never a burden to the children.

This device is placed in the children's chest, children running around and panic, the heartbeat and action status is rapidly changing, then within the camera will automatically capture the surrounding conditions, through the Internet to the guardian, guardian can remotely confirm the position of the child is located and the action changes.

Sensing imaging technology advantage extends achievements for the medical sector growth

Canon (China) medical equipment Division General Manager at three Kazuo

-Dialogue Canon (China) medical equipment Division General Manager at three Kazuo

Recently, 60th session China International medical equipment fair held in Suzhou.

In more than 2000 enterprises to participate in the Grand Expo, domestic and international, multidisciplinary, multiple categories, multiple levels of high-tech achievements together. As the first enterprise identity debut international medical exhibition of Canon (China) co., Ltd., is relying on its image sensor manufacturing, technical advantages in the field of medical imaging continues to grow, order.

Recently, Canon (China) medical equipment Division General Manager Mr. media interpretation at the Canon in the medical areas of disease into the market and to dream.

Canon medical, not fn

"In fact, the medical field is not a new field of Canon company.

"Canon (China) medical equipment Division General Manager Mr. so explained at. "Canon's founder Mr. Mitarai itself is a doctor. Canon since 1940 it released the first x-ray photography equipment indirectly, had been engaged in the manufacture and sales of medical devices. And in 1998 was developed and published flat panel detector that Canon has accumulated in global sales flat panel detector and up to 6 thousand units. Canon brand in the medical field is gradually accumulated.

Started by Canon Optics, imaging sensor manufacturing and technology with unique advantages.

The fair, Canon (China) was the first to enterprise identity debut, and display the current medical imaging industry new DR system core products – flat panel detector. Exhibits include for the first time in the Chinese public display of Canon's latest digital x-ray imaging systems, as well as the latest CXDI-60G obtained the registration certificate of the SFDA CXDI-50C, CXDI-40EG, CXDI-40EC, etc. Canon on Chinese medical device market of evident.

International computer-based x-ray radiography (CR) and digital x-ray imaging system (DR), CR is gradually evolving to DR, in this irreversible trend, the digital medical imaging has been pushed into the center of the stage.

A check with higher efficiency and better image and less x-ray dose of DR era, has let industry full of hope. At the same time, DR system core, one of the flat panel detector (FPD), its design life of up to hundreds of thousands of exposure. These advantages make the Canon on flat-panel detector of absorbed, has special significance.

Advantages of the extension to meet the needs of the community

"Because of the advantages of traditional image areas, Canon was able to meet the extension more community needs.

"Gates General Manager said. China medical device market in recent years the rapid pace of development, market demand is also growing as a Canon.

Medical industry data shows, the next five years, the medical device market in China will gradually catching up with United States, becoming the world's largest medical device market, with nearly 2 million Chinese medical institutions need for device update.

Market demand is Canon's mission, in order to allow people to live more healthy, Canon will continue their efforts.

Canon heavyweight launched the industry's largest portable flat panel detector CXDI-50G, become the most watched on the market of the product.

Canon's full range of products, DR because of its quality, safety and reliability, excellent performance, as well as do from hardware production, software development, sales and marketing to the after-sales service of complete solutions, but by the Chinese medical imaging sector of particular attention.

In addition, Canon also as OEM manufacturers to other medical device manufacturers to provide the core parts of DR system – flat panel detector that makes Canon DR system to better serve the community, and promote public health level.

At the same time, Canon has also taken the core flat panel detector technology and hospital consolidation, through unified Canon brand, to build a firebrand DR application banner.

Build a "Canon clinical demonstration base," fad of sophisticated medical imaging

Currently, Canon provides core DR systems for core parts, worldwide, are widely used in the mobile field hospital, ambulance, animal hospital, different uses of the environment.

At the same time, this year the disaster area to donate, and even the physical examination, pandas have motion disabilities, or are in need of urgent imaging and other specific scenario, Canon flat panel detector that embodies a portable, convenient enormous advantages, can do much more thoughtful to the consumer.

In addition to the application of these special occasions, Canon is working with China to reach some hospitals, push the "Canon" clinical demonstration bases.

"And the Chinese medical institutions in model Hospital project cooperation, can help the user's cognitive Canon technology and product application, will bring to the Chinese medical areas of change. "Mr. so that at the time.

"Medical treatment to begin to understand which hospitals can use Canon's exclusive LANMIT image sensor core technology DR system, hospitals, and Canon, are a win-win situation.

"It has been disclosed," Canon clinical demonstration base "in the year will reach 20, and the future extension of the scope and volume, also will increase further.

At the same time, the Canon with the production, from hardware to software development, from market sales, to service of the complete system solution for DR, winning numerous professional institution.

Active layout Chinese medical market of Canon, more in the pipeline for DR systems, or parts maintenance of value-added service pack.

In the face of continued volume growth of Chinese medical market, as the medical field digital edge DR increasingly heated debate, let us on the development of future medical care have more expectation.

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New micro-sensor in medical instrument application solutions

1. preface

Today, with intelligent sensor technology picks up probe of respiratory medical monitors have heard, this is an ideal solution for all kinds of emotions and make substantial link between respiratory problems and can be used to the real record of a person's respiratory conditions and changes.

In this article on respiratory monitors with miniature sensor-Silicon Piezoresistive sensor (SPRT) and MAX1450 signal conditioner or MAX1457 formed new intelligent sensors and in function of the technical programme for an analysis and presentation.

2. respiratory medical monitors and smart sensors and technologies (its composition chart, see Figure 1 below)

2.1 respiratory medical monitor (see Figure 1, right)

　　

　　

The monitor is used to monitor the respiratory status and can give an approximate depth of breathing.

This monitor for monitoring some can be used to evaluate important parameters of anxiety: breathing frequency, breathe evenly and exhale and inhale the intermission between. Calm, positive emotion often leads to exhale is longer than the duration of inhalation, than parameters, can be from one side to reveal human anxiety. Relatively high levels of thoracic breathing (relative to the abdominal breathing) can also be instructions for anxiety. Monitor on chest breathing observation reflects the monitor has a large amount of Visual information.

2.2 intelligent sensor technology

Figure 1 respiratory monitors using silicon Piezoresistive sensor (SPRT — Silicon piezoresistance transducer) detect when you inhale and exhale corresponding pressure reduction and increased.

SPRT output is fed into a MAX1450 signal conditioner or MAX1457, chip or MAX1457 MAX1450 signal conditioner chip and on the incentive to drive SPRT (or current source), the inherent error was SPRT-infeed MAX1450 or after and correction MAX1457, then after compensation voltage signal fed with 12-bit analog-to-digital converter (ADC) MAX1202. ADC output (digital pressure signals) into a PC interface MAX3232, and converted to RS-232 level. Last signal is passed to the PC system, so that you can demonstrate respiratory waveform, and on the above mentioned parameters for analysis.

3. about Silicon Piezoresistive sensor (SPRT)

3.1 Silicon Piezoresistive sensor detection principle (SPRT)

Silicon Piezoresistive sensor typically configured as a close Wheatstone bridge.

When there is pressure sensitive to the SPRT bridge arm (as shown in Figure 2a), diagonal leg resistance value of R is the same as the direction, will take place the same amount of change, i.e. R + R and R-△ △ R. When a diagonal leg two resistance in the pressure increases, the other diagonal leg of resistance values, and vice versa. For SPRT half sensitive bridge (see fig. 2b), only half-arm resistance value changes. Whether it is a full-bridge or half-sensitive bridge sensor with high sensitivity (> 10mv/v), good linear, temperature stability and no signal hysteresis, etc., the measuring range can be from destructive limit.

　　

　　

3.2 Silicon Piezoresistive sensor applications

Today, thanks to the new IC technology has been able to accurately calibrate SPRT, Silicon Piezoresistive sensor applications range from the low precision inspection extends to the high-end segment.

Makes up for in the past, SPRT typically can only be used in low-precision detection and on high-end products to use expensive strain gauges, etc. But to apply Silicon Piezoresistive sensor must resolve error compensation-calibration technology to increase the precision. To do this, first and foremost with Silicon Piezoresistive sensor error for analysis.

4. about Silicon Piezoresistive sensor (SPRT) error

Calibration SPRT sensor main difficulty lies in the fact that their scope is very wide margin of error, a different process for the production of SPRT sensors have different types of errors and error range.

Even from the same manufacturer of same type sensor margin of error, there are slight differences. SPRT sensor error factors include: full partial signal with temperature variations strongly nonlinear (up to 1% oK); a large initial offset (up to 100 per cent of the full rate or higher) and offset drift over temperature strongly. To a certain extent, these defects can be compensated by the electronic circuit.

Temperature, Figure 2 (a) (b) as shown in the two types SPRT bridge resistance (between the Vcc and the equivalent resistance) to very wide pressure range remains fairly constant, however, with increasing temperature, bridge resistance increased significantly, driven by a constant current source if bridge, the bridge voltage (means the Vcc and ground between equivalent resistance and constant current source output current of the product) is incremented.

When the bridge voltage as the temperature increases, the SPRT sensitivity is increased. On the other hand, if you keep the bridge voltage constant, SPRT pressure sensitivity also increases with temperature. Therefore, the pressure sensitivity by SPRT two competing factors: temperature and the temperature of the bridge voltage. This bridge resistance or bridge voltage changes can he modern signal conditioning circuits IC utilized to correct SPRT sensitivity in the temperature range of error. It is worth mentioning that this type of signal conditioning circuits IC through bridge resistance changes to correct sensitivity with temperature changes. According to the main SPRT error analysis of the factors that will be targeted for correction and compensation. The following are currently used traditional correction and modern correction and simplify compensation method for introduction.

5. traditional correction method

　

Figure 3 circuit as legacy correction scheme

　　

　　

It can compensate for SPRT precision to the appropriate level, and can SPRT disorders, disorders of temperature drift (OFFSETTC) and SPRT sensitivity adjust temperature drift.

The sensitivity of the SPRT temperature drift is associated with a partial Elm (FSO) temperature drift, the two parameters (SPRT sensitivity temperature drift and full partial Yu-out temperature drift) is proportional to the temperature characteristics of interoperability, circuit nulling resistor Rjz to compensate sensor at room temperature for offset voltage, temperature sensitive resistor Rts and Rtz (or R ' tz) temperature error for correction. Mentioned earlier, the bridge resistance increases as the temperature rises, so that sensors both sides voltage Vo Vo +-() have also increased, this increased voltage △ Vo + Vo-makes the sensor's sensitivity is increased, that is, given the pressure it will output a higher voltage.

However, if you maintain a constant voltage sensor, the sensor's sensitivity is increased as the temperature of the lower (or negative sensitivity coefficient), but because the bridge resistance temperature impact increases, it is the sensitivity to variation coefficient is greater than negative sensitivity coefficients, so that full partial output (FSO) tend to increase as temperature increases.

Resistor Rts can temperature rise bypass off part of the bridge circuit current to offset these effects. Similarly, Rtz or R ' tz can offset calibration of drift. Select the Rts or circuit R ' tz depend on direction maladjusted temperature drift.

This traditional correction method has the advantage that the program is simple, cheap, but the main problem is the interaction between the compensation components, so that the calibration is very difficult, and limits can achieve the precision, the calibration nor easy to use electronic adjustment.

6, modern correction-compensation technology

Since the margin of error SPRT range is very wide, and therefore must be used by modern and streamlined compensation method to calibrate.

Current modern correction-compensation technology is a new type of signal conditioning MAX145 chips and combo, SPRT into intelligent sensors and technologies.

Use a signal conditioning MAXl457 IC to drive respiratory monitors Silicon Piezoresistive sensor (SPRT), and calibration sensor errors.

MAXl457 it with one used to drive sensors controlled current source and a bridge for sampling ADC voltage of the sensor (ADC).

MAXl457 also includes a programmable gain amplifier (PGA), is used to enlarge the sensor differential output; and 5 number DAC (digital-to-analog converter), used for the correction of various sensor errors.

Because the sensor output is a weak signal, the output voltage of PGA is not sufficient to drive the ADC. To do this, the built-in amplifier MAXl457 can be used to enhance the PGA's output to an appropriate level.

Because the bridge voltage increases with temperature, the temperature dependency can be used to compensate full partial output (output FSO-Full span) of temperature error.

For constant current source excitation current bridge, full partial output (FSO) decreases as the temperature to rise, resulting in a full partial output temperature related errors (FSOTC). However, if the bridge voltage with the temperature rise to a certain rate, just compensation off full partial sensitivity with temperature drop, full partial output (FSO) will remain constant.

How to use this 6.1MAXl457 method calibration temperature induced full partial output (FSO) errors (see Figure 4).

　　

　　

First of all, by the ADC to quantify the bridge voltage, depending on the quantitative results, identify an advance meter open okay four correction coefficient (has saved in EEPROM) give FSOTC DAC.

And DAC output voltage on bridge excitation current is adjusted, adjusted excitation current changed the bridge voltage, thus compensating the specific temperature, sensor sensitivity changes caused by full partial output (FSO) error. In order to achieve smooth correction, the bridge voltage is used as the reference input FSOTC DAC, in the adjacent two digital compensation points (from ADC to EEPROM) for simulation of compensation. The same method is used to compensate for misalignment of temperature drift (OFFSETTC), the difference is that the output voltage of OFFSETTC DAC are fed human PGA output sum node (instead of the current source MAX1457).

6.2 on these four temperature correction coefficient calculation step description

First of all, the sensor and the minimum temperature gets MAXl457 at different pressures of sensor data, and then, place the sensors and the highest temperature MAXl457 gets different pressures of sensor data.

Use these limiting temperature point data, designed for MAXl457 designed application software to calculate the four correction factor: full partial output (FSO), full partial output temperature related errors (FSOTC), offset-offset (Offset), disorders of temperature offset (OFFSETTC), these four factors can amend an order error SPRT.

To get the precision of 0.1% MAXl457 allows specific temperature compensation, you only need to provide temperature calculation FSOTC and calibration by the user decides to OFFSETTC point number (up to 120 points).

If the sensor error with good repeatability, SPRT and MAXl457 combination can get better than 0.1% accuracy.

MAXl457 compensation technology relative to figure 3 for the traditional approach has clear advantages.

MAXl457 eliminates compensation interaction between components, which benefited from the independent disorders and full-scale adjustment: disorder in PGA output for compensation,But FSO amendment implementation through the current source. Another benefit is that since for different temperature point for specific amendments, for increased accuracy possible. This approach is essentially better than using external resistors, since the latter failed to point at a specific temperature sensor for precise compensation.

Because the MAX1457 accuracy can be much higher than a respiratory monitors, chose it, mainly because of its internal also contains an additional amplifier, you can breath monitoring instrument sensors to zoom in on low level signal.

Because the monitor can MAX1457 work in a wide temperature range, SPRT and MAX1457 combination applied for superior accuracy, it can be applied to space exploration and diving apparatus, etc.

7. practical simplify correction scheme

Because of the precision MAX1457 can be much higher than a respiratory monitors, so there is no need to use 16-bit resolution DAC.

Usually adopts MAX1450 signal conditioner for simplified school compensation programme (see Figure 5).

　　

　　

7.1MAX1450 signal conditioner functions the same as the nature and the MAX1457 is replaced with resistance to error correction DAC.

Than by MAX1450 MAX1457 considerably less precision calibration point, which is 1%.

Is usually used for a mixed programme, the programme will MAX1450 and laser trimming resistor (Figure 5 shows the external trimming resistor) combination provides a low cost solution, which uses MAX1450 signal conditioner with external laser trimming resistor provides 1% accuracy. Adjusted Figure 5 RFSOA trimming resistor is used to set the initial (FSO) sensitivity and offset temperature drift compensation (OFFSETTC) is through ROFFA and fine tune the resistance adjustment ROTCA.

7.2MAX1450 pin function introduction £ º

A0 programmable gain amplifier (PGA) gain settings the lowest bit input; programmable amplifier gain set A1; A2 programmable gain amplifier (PGA) gain settings the MSB input; SOTC programmable gain amplifier current overcurrent control switches; SOFF programmable gain amplifier power off; OFFTC temperature offset correction input; OFFSET offset input; BBUF belt buffer bridge voltage output; FSOTRIM bridge driving current set input; OUT output voltage-controlled amplifier; ISRC current source base; BDRIVE excitation current output; INM sensor negative signal output; INP sensor is signal output; VDD power supply voltage; and VSS.

8. concluding remarks

Due to the new signal conditioner IC technology, have been able to accurately calibrate SPRT error, Piezoresistive sensor in addition to the application in the medical field, you can expand into other areas of industrial safety as well as military and other high-end products.

This from the above several designs that, by applying Silicon Piezoresistive sensor (SPRT) and MAX1450, MAX1457, signal conditioner chip consisting of smart sensors enable research and development of new types of respiratory monitors with high accuracy, low cost, sophisticated features, also demonstrated in the high end without requiring expensive strain gage's vision is achievable.

According to initial use, the new silicon Piezoresistive sensor (SPRT) and MAX1450, MAX1457, signal conditioner chip consisting of smart sensors enable research and development of new types of respiratory monitors after medical institutions and integrity index (mental status changes trigger physiological change detection) verification instrument in recruitment and assessment of the trial, the effect is good.

Especially in the diagnosis and treatment in the hospital so that doctors on patient's respiratory and cardiopulmonary status of testing, not only features strong and indicators have greatly improved accuracy, according to numerous trial, its qualitative (PC monitor) and quantitative (digital recorder) measurement results for doctors determine symptoms have completely more scientific basis.

E based on AT89C51SNDlC treatment instrument design

1 Introduction

Currently takes two electrodes tablets covered with the body parts of symmetry of electron treatment instrument, through the electrode voltage fluctuation on chip and the treatment of human parts resistors role in the treatment position produces human ability to sense the pulse of neuromuscular stimulation current, so that its systolic and diastolic, produce motion effects to achieve therapeutic purposes.

But the current market for this type of treatment instrument resulting ripple voltage of only a few, because of the ripple current frequency cycle fixation, if a treatment position long-term acceptance of the pulse could have the effect of treatment, causing spontaneous tension, reducing the treatment effect. To resolve this issue, the issue of random MP3 music signal into treatment instrument, so that the audio signal and 2.4 kHz frequency frequency of treatment for a variety of modulation, pulse voltage and frequency cycle constantly transform ripple current. They fluctuate along with the music signal and work, so that patients enjoy their favorite music while receiving treatment, distracting, relieve stress, which can help improve treatment outcomes.

Propose an approach based on embedded devices AT89C5ISNDlC electronic instrument design and spread D/A, mass storage, keyboard, display, implement basic MP3 function; control AT89C5lSNDlC produces audio and 2.4 kHz frequency signal, using a digital circuit complete both signal FM, zoom in, the transformer isolated output voltage pulse therapy.

2 works

Based on the embedded device 89C5lSNDlC electronic instrument system hardware structure shown in Figure l, divided into signal generation and control module, FM output modules, power modules, part 3.

Signal generation and control module is a massive memory microcontroller, 89C5lSNDlC, keyboard, USB port, LCD display, and D/A converters, audio amplifier.

When treatment instrument USB port into the computer's USB port, single-chip detection after U disk function, you can select the right MP3 songs are copied to the USB disk (instrument). When treatment instrument USB port not inserted computer USB interface, the instrument can be used as MP3 broadcast. Through the function keys set songs, treatment time, volume, start/stop key control treatment instrument. Treatment, the SCM has two inverted 2.4 kHz frequency signal frequency, F F if and an audio signal F audio, while at the same time will be stored in MP3 format songs decoded into audio digital signal, then by a D/A conversion amplifier, sent to the headset or loudspeaker.

Frequency modulation output module is FM, amplification, output dose adjustment and output transformers, electrode tablets.

Two-channel RP-if signals and one audio signal with frequency modulation, frequency modulation of the signal after enlargement, the output voltage of the transformer isolation output pulse, covered by electrode plate symmetric to the human body treatment position, the human body will feel with music fluctuating current stimulation. Through output adjustment, suit human dose different treatment position and skin stem humidity differences can bear aware of current requirements.

Power supply module provides 15 V, 5 V, 3.3 V system operating voltage.

When treatment instrument USB port into the computer's USB connector, single-chip implementation of U disk function, from computer USB interface provides + 5 v power supply. Therapy, physical therapy for the power supply is 220 V AC power supply via transformer, Rectifier, voltage, filters.

3 hardware system design

3.1 MCU introduction

Embedded device AT89C5lSNDlC set CPU, MP3 decoder, USB controllers, and other devices.

AT89C51SNDlC has 51 series single-chip microcomputer control and the ability to scale to MP3 and USB disk, using the PLCC packaging, its internal structure diagram shown in Figure 2.

AT89C5lSNDlC P0, P1, the P3 port features and compatible 5l series microcontroller, additionally increased the 8-bit P4 port, 4-bit port P5.

Clock circuit and the reset circuit connection method and 51 series microcontrollers.

The first time you use the devices need to separately download the USB driver, the user program.

64 in AT89C51SNDlC KBROM, address FOOOH-FFFFH is assimilated better Boot Loader code 4K bytes. The factory, the BLJB position 1, this power-up executed automatically after the Boot Loader code and wait for the download from the USB Flash disk driver or user programs target code. Once the download is complete, you should download the software will BIJJB position 0, again with electricity, to automate the user program. If you still need to modify the user program, you can reset the ISP pin low level. The power-on reset, the automatic boot Boot Loader code execution, wait for the user program. Restart the user should be ISP PIN reset to high level.

3.2 signal generation and control module

Signal generation and control module circuit diagram shown in Figure 3.

For MP3 and USB disk function, AT89C51SNDlC microcontroller need external a NAND Flash mass storage-, this selection of 16 MB of the data line K9F2808U0C I/I/00 ~ 07-P0 port, control line received P5 port. MP3 audio decoder output signals, and the MCU DOUT, DLCK, SCLK pin by DSEL, D/A converters CS4330, after enlargement, output to headphones listening to MP3 songs. LCD-MCU port P2, and keyboardMatching to display the current status of the instrument. There are four on the keyboard is pressed, the "volume/songs/timer" feature keys received P1.0 pin, respectively and P1.1 pin made of "next" button and the next P1.2 pin "previ-OHS" keys, to achieve the volume adjustment, song selection, treatment timing functions; and "start/stop" button then P1.3 pin.

AT89C5lSNDlC MCU P3.3 pin is used to detect the current using u disk or MP3 player.

If the treatment instrument USB leader received a computer's USB port, the detected P3.3 PIN reset, do u disk program, in which case the SCM jobs powered by the USB interface; otherwise, P3.3 pin detected low level, the implementation of the MP3 program. If signal F MF, MF and audio signal F F audio respectively AT89C5lSN — DlC MCU P4.4, P4.5 and DOUT PIN.

3.3 FM output module

Frequency modulation output module circuit schematic diagram shown in Figure 4.

Audio signal F audio separately and if signal F if and if phase modulation, producing two phase contrast modulation waveform, then by 9013, 8050, D880Y zoom evacuation to transformer two input terminals. Intermediate tapped voltage transformer by Ma table received dose adjustment circuit. 47 k Ω resistor that dose adjustment potentiometer, downwards then Ma table indicates the current smaller, but larger. Transformer isolated output voltage and input voltage synchronization changes. Output voltage through the electrode tablets and human contact, in the human body produces a perception of current. According to the physical location of different, and the extent of wet and dry skin, human perception-current. When you need to adjust the potentiometer physical therapy, physiotherapy, feeling comfortable.

3.4 power module

Therapeutic apparatus required 3.3 V, 5 V, 15 v supply voltage from the power supply module, its principle as shown in Figure 5.

3.3 V voltage can be supplied to the use of embedded devices AT89C51SNDlC; 5 V voltage can be supplied to the use of FM, amplifying circuit; 15 V voltage available to adjust the output dose. Of these, 5 V voltage used 78L05, V voltage used LDll17S33 3.3. When you use U disk function, physical therapy for the USB port of inserting PC USB interface, no 220 V AC power supply, single-chip voltage is supplied by the USB interface.

4 system software design

And hardware functionality, system software design process as shown in Figure 6; the keyboard interrupt service program flow as shown in Figure 7.

5 conclusion

Design of the portable device battery monitoring system using programmable battery monitoring chip BQ27210 and external high integrated processor C805lF304 on battery power, you can use time, temperature, voltage, and other information in real-time monitoring, and through an I2C bus for data transmission, with high precision and small size, low cost, has now been applied to some handheld data collection devices.