CN104516387B - Constant flow source supply circuit of respiration signal sensor based on air cushion bed - Google Patents
Constant flow source supply circuit of respiration signal sensor based on air cushion bed Download PDFInfo
- Publication number
- CN104516387B CN104516387B CN201410768774.9A CN201410768774A CN104516387B CN 104516387 B CN104516387 B CN 104516387B CN 201410768774 A CN201410768774 A CN 201410768774A CN 104516387 B CN104516387 B CN 104516387B
- Authority
- CN
- China
- Prior art keywords
- sensor
- resistance
- supply circuit
- operational amplifier
- current source
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Abstract
The invention discloses a constant flow source supply circuit of a respiration signal sensor based on an air cushion bed. The respiration signal is collected by a sensor, and the structure of the sensor is a Wheatstone bridge structure consisting of four P-type resistors. A semiconductor film is installed in the P-type resistor; the +IN input terminal of the sensor is connected with the output terminal of an operational amplifier; the in-phase input terminal of the operational amplifier is connected with one terminal of a resistor R1, the cathode of a voltage-regulator diode D1 and the -IN input terminal of the sensor at the same time, the other terminal of the resistor R1 is connected to the supply voltage; the inverted input terminal of the operational amplifier is connected to the grounding voltage by a resistor R2; and the anode of the voltage-regulator diode D1 is connected with one terminal of a capacitor C1 and the grounding voltage, and the other terminal of the capacitor C1 is connected to the ground. While the constant flow source is used for supplying the power, the output voltage of the sensor is not affected by the temperature, the sensor precision and the like, the number of the instruments is reduced, the cost is reduced, and the stability of the sensor output is higher.
Description
Technical field
The present invention relates to a kind of constant current source power supply circuit, more particularly to a kind of breath signal sensing based on air fluidized bed
The constant current source power supply circuit of device.
Background technology
Sleep apnea syndrome (Sleep Apnea Syndrome:SAS it is) that human life and the potential of health are killed
Handss[1].SAS is that apneic sleep disorder occurs in a kind of sleep.According to R＆K handbooks[1], the respiratory disorder in sleep quality
It is divided into two kinds[2]：1. apnea (Apnea)：The air-flow of mouth or nose stops flowing beyond ten seconds；2. low breathing
(Hypopnea)：Ventilation volume is less than 50% time more than ten seconds.Medically, " apnea/low spiro-index " (Apnea-
Hypopnea Index, AHI) define the number of times for referring to apnea and low respiration case in average a hour.In adult, generally will
AHI is diagnosed as with sleep apnea higher than 5；In child, diagnosis numerical value does not have verdict, and someone is defined as AHI higher than 1.5
Children sleeping asphyxia[3].Apnea syndrome can be generally divided into following 3 type：Obstructive sleep apnea
(OSA), central respiratory arrest (CSA) and mixed type sleep suspends (MSA)[3].Wherein OSA patient is the most universal, accounts for 84%
Ratio.OSA and CSA's differs primarily in that whether respiratory tract is unobstructed.
The clinical manifestation of adult's asphyxia is that the sound of snoring is huge；The sound of snoring is interrupted because of asphyxia often, then occurs breathing；Day
Between drowsiness, focus in the daytime, cognitive competence declines；Early morning has a headache；Increased weight etc..Night shown as and asphyxia in child there is
There are snoring, Breathiness exception during sleep；Have daytime active and drowsiness[4].These symptoms compare very common, also therefore hold
Easily it is ignored.In fact, statistics show, the sickness rate of external sleep apnea syndrome is 2% to 4%, China
Statistics is probably 3% to 4% or so, and has the trend for improving year by year[5], apnea syndrome is the most universal in middle-aged male；
The sickness rate of male is about 2 to 8 times of women.
The wherein apnea syndrome of premature infant, because premature infant's sickness rate is high, resistance is weaker, harm is serious, particularly
It is concerned.Because the maincenter respiratory system of premature infant develops imperfection, adult is different from, it adjusts the limited in one's ability of breathing, is held
Easily there is respiratory disorder, thus this colony suffer from apnea syndrome likelihood ratio general groups it is much higher.According to clinic
Statistics, about 40~50% premature infant has the symptom appearance of periodic breathing；Periodic breathing is one kind of adnormal respiration, table
It is now being alternately present that accelerated breathing reinforcement slows down.Because premature infant is weak from the ability that main regulation is breathed, with periodically
Half is there are about in the premature infant of breathing can develop into asphyxia.And the less premature infant of gestational age, body function gets over imperfection,
The probability for suffering from apnea syndrome is bigger[6].In addition the factor such as anoxia, Temperature changing, hypoglycemia is equally possible causes new life
The apnea syndrome of youngster.Asphyxia is a kind of serious physiological barrier for neonate.When discovery neonate occurs
During asphyxia, need as early as possible to implement it breathing help and other urgent measures, the normal work of the body that sustains life.Such as do not have
Have and processed in time, over a long time anoxia can cause brain injury, amyotrophy etc., to neonatal body and intelligent development not
Profit, even death by suffocation is caused when serious[7]。
The asphyxia of adult and child is simultaneously not affected by extensive concern, although it does not have the diseases such as cancer, pulmonary tuberculosis
Fatality rate it is high, but its and society personal to patient all has significantly harm, as shown in Figure 1.It not only affects patient
People rests, and causes personal tired out in the daytime；And long-term anoxia seriously damages the body function of each internal organs of body in sleep procedure[8],
Can for example cause heart blood supply scarce capacity, blood pressure to increase, sensation of oppression over the chest with shortness of breath, dizziness and blurred vision, endocrine disturbance and myasthenia etc., sternly
Even die suddenly during weight.For old people, asphyxia may cause or increase some cardiovascular disease；For child,
Asphyxia may cause its delayed, physique of development thin and weak；For the development that anemia of pregnant woman's asphyxia may affect fetus；Except this with
Outward, asphyxia usually bothers the sleep of people around, makes troubles to family and society.
In recent years resident increasingly payes attention to concept of health, the reason of home health care (Home Health Care-HHC)
Thought is gradually rooted in the hearts of the people, and investment of the resident to health is more and more.Home health care has become medical science development
One of important directions, while being also the important symbol of progress of social civilization[9].Domestic monitoring instrument is home health care
Pith.Sleep monitor instrument shows huge market potential.Many flourishing states release domestic sleeping monitor, and shape
Into certain scale.The domestic sleeping monitoring market of China also gradually grows.Compared with Special Medical monitor, domestic monitoring instrument
The features such as device more focuses on inexpensive, easy to operate, noiseless and portable, table 1 is several domestic sleeping monitoring in the market
The Typical Representative of instrument[10]。
The current typical household sleep monitor instrument both at home and abroad of table 1
Sensor in monitor is accurately detected these physical quantitys as human body and the coupling link of Medical Instruments
Change, and it is converted into the signal of telecommunication.And by signal processing technology, by the breath signal feature extraction wherein contained out,
So as to reflect the breath state of human body.
Breath signal belongs to the faint physiological signal of human body, the body environment and surrounding complicated and changeable in human body
In, have the characteristics that[11]：
(1) signal is weak, noise is strong.The vibration amplitude very little of the breathing of human body, pressure transducer collects signal of telecommunication amplitude
Also it is very little (mV ranks).Due to using mattress formula detection meanss and piezoresistive pressure sensor, the initial gas pressure reduction of air fluidized bed,
Standing up action, sleeping posture adjustment etc. all can be detected by the sensors；These jam-to-signal breath signal amplitudes are much greater.Cause
This breath signal belongs to the small-signal under strong noise background.The characteristics of breath signal amplitude is low, noise is strong, on the one hand requires to adopt
With differential pressure measurement, common-mode signal interference, prominent difference mode signal are reduced；On the other hand selection high accuracy, highly sensitive is also required that
Sensor.
(2) frequency is very low.The respiratory frequency of human body is general very low, normally between 0.1Hz~0.6Hz；Human body is exhaled
Energy absorption is concentrated under normal circumstances very much.
(3) regular and non-regularity.Breath signal has regular and non-regularity.The regularity of breath signal is referred to
Respiratory waveform of the same person under equivalent environment, state, frequency, amplitude are more stable；Typically will not occur larger or anxious
Acute change.The non-regularity of breath signal refers between Different Individual, under different detection meanss, under different conditions that breathing is believed
Number amplitude, frequency and waveform can all have larger difference.The non-regularity of breath signal is to a certain extent to breath signal
Process brings difficulty.
(4) easily changed by ectocine.Breath signal is in the environment of human body body and around, breath signal
Unavoidably mixed by various interference signals, as shown in Fig. 2 affecting the extraction and process of breath signal.Except above-mentioned
Stand up action, stance adjustment etc. are outer, and human body body is produced heart beating, muscle beat (frequency is in below 1.5Hz) etc. to be also introduced into making an uproar
Sound, in addition it is contemplated that the various interference (such as mattress vibrations) of surrounding and sensor and its signal processing circuit are normal
It is subjected to Hz noise and electronic component self-noise of 50Hz etc..For different interference, need to take different noise reductions to arrange
Apply.
List of references：
[1] Huang Renhan, Zhao Xueyan, Rong Qiguo；The Progress in Research of Biomechanical Properties [J] of sleep apnea syndrome, mechanics
Progress, 2010,40 (3)：298-308.
[2]Rechtschaffen A,Kales A.A manual of standardized terminology,
techniques and scoring system for sleep stages of human subjects[J].1968。
[3] Wang Yu, Zhang Ying, Wang Hailing etc.；Obstruction sleep apnea-hypopnea syndrome Analysis of Clinical Risk Factors
[J], Chinese clinicist's magazine, (electronic edition) 2009,3 (3)：18-21.
[4] Cai Xiaolan, Liu Hongying, model is offered good etc.；The diagnosis of pediatric obstructive sleep apnea low syndrome
[J], Chinese hals,Nasen und Ohrenheilkunde magazine, 2003,38 (3)：161-165.
[5] Luo Xianfang, king can still, Cai Yingyun；The dialectical of sleep apnea syndrome and treatment [J] are stated in examination, in Zhejiang
Doctor's magazine, 2003,38 (11)：490-491.
[6] Yang Lianfang, Wu Lijuan；Apnea of prematurity sickness rate and analysis of Influential Factors [J], Zhejiang preventive medicine,
2007,19 (11)：47-47.
[7] Wei Lili；Apnea of prematurity therapeutic advance [J], foreign medical science：Pediatrics fascicle, 2001,28 (1)：
51-51。
[8] Li Jia, Wu Shuicai, Li Yanzheng etc.；The progress [J] of Domestic health mornitor, medical equipment information,
2007,22 (3)：55-58.
[9] Chen Feiming；Portable neonate physiological signal monitoring system designs [D], Harbin Institute of Technology, and 2012.
[10] kind book is put down, Jiang Shisen；Sleep apnea and multisystem organ injury progress [J], Chinese tuberculosis and
Breathing magazine, 1997,20 (1)：39-41.
[11] Zhou Jie；Processing of biomedical signals method summarizes [J], brilliant work, and 2012,8：285.
The content of the invention
For the problem that prior art is always present, it is contemplated that the features such as sensor output signal bandwidth and amplitude, in order to pass
Sensor is not affected by temperature, sensor accuracy etc., and the stability for exporting sensor is higher, at the same reduce number of devices and into
This.The present invention provides a kind of constant current source power supply circuit of the breath signal sensor based on air fluidized bed, is mainly put using computing
Big device devises a constant-current source.
In order to solve above-mentioned technical problem, a kind of constant current source power supply of the breath signal sensor based on air fluidized bed of the present invention
Circuit, wherein, by sensor acquisition, the structure of the sensor is the Wheatstone bridge knot of 4 p-type resistance compositions to breath signal
Structure, there is a semiconductor membrane inside the p-type resistance, constant current source power supply circuit includes operational amplifier, resistance R1, resistance R2, steady
Pressure diode D1 and electric capacity the C1 ,+IN inputs connection of the sensor is connected with the outfan of operational amplifier, the computing
The in-phase input end of amplifier is while the one end, the negative electrode of the Zener diode D1 and the sensor with the resistance R1
The connection of-IN inputs, the other end of the resistance R1 is connected to supply voltage, and the inverting input of the operational amplifier leads to
Cross the resistance R2 to be connected with ground voltage, the anode of the Zener diode D1 is while the one end and ground connection with the electric capacity C1
Voltage is connected, the other end ground connection of the electric capacity C1.
Wherein, AD823AR operational amplifier of the operational amplifier from the production of Analog Device companies.
Compared with prior art, the invention has the beneficial effects as follows：
NPC1210 series low pressure sensors adopt constant current source power supply, due to NPC1210 series low pressure sensors inside mainly
The wheatstone bridge configuration that structure is made up of strain diaphragm.When powering compared to constant pressure source, the sensing of wheatstone bridge configuration
Device adopt constant current source power supply when, sensor output voltage only with the increment of membrane resistance and the linear pass of constant-current source size of current
System, will not be subject to temperature, sensor accuracy etc. to affect, and not only reduce number of devices and reduce cost, and sensor is exported
Stability it is higher.
Description of the drawings
Fig. 1 is that the issuable harm of apnea syndrome affects schematic diagram；
Fig. 2 is that breath signal is mixed impact schematic diagram by various interference signals；
Fig. 3 is constant current source power supply circuit theory diagrams of the present invention；
Fig. 4 is application example schematic diagram of the present invention.
Specific embodiment
Below in conjunction with the accompanying drawings technical solution of the present invention is described in further detail with specific embodiment.
As shown in figure 3, a kind of constant current source power supply circuit of the breath signal sensor based on air fluidized bed of the present invention, wherein,
By sensor acquisition, the structure of the sensor is the wheatstone bridge configuration of 4 p-type resistance compositions to breath signal, the p-type electricity
Resistance is internal a semiconductor membrane, constant current source power supply circuit include operational amplifier, resistance R1, resistance R2, Zener diode D1 and
Electric capacity the C1 ,+IN inputs connection of the sensor is connected with the outfan of operational amplifier, the homophase of the operational amplifier
Input connects with-IN the inputs of one end, the negative electrode of the Zener diode D1 and the sensor of the resistance R1 simultaneously
Connect, the other end of the resistance R1 is connected to supply voltage, and the inverting input of the operational amplifier passes through the resistance R2
It is connected with ground voltage, the anode of the Zener diode D1 is connected with one end of the electric capacity C1 and ground voltage simultaneously, institute
State the other end ground connection of electric capacity C1.Wherein, AD823AR fortune of the operational amplifier from the production of Analog Device companies
Calculate amplifier.
As described in Figure 4, constant current source power supply circuit of the present invention is used for based on the breath signal harvester of air fluidized bed, this is exhaled
Inhaling signal pickup assembly includes air fluidized bed, and the air fluidized bed is made up of multiple air chambers arranged side by side, 2 spaced apart gas therein
Room is measurement air chamber 1, and remaining air chamber is connected to one by a connecting conduit 3 respectively to support air chamber 2, two measurement air chambers 1
The input of piezoresistive pressure sensor 4, between described two measurement air chambers 1 balance pipe 5 is connected with.The pressure drag type pressure is passed
Sensor 4 selects a in the low pressure sensor of the NPC1210 series of GE companies.Its main feature has：1. in 0~60 DEG C of scope
It is interior with temperature compensation characteristic, the temperature range that domestic monitoring is used is covered substantially；2. pressure range is -10~10 inches of water
Post, overload pressure 5Psi, Full-span output voltage is 50mV, reaches design to sensitivity and the requirement of range；3. input impedance
2500~6000 Europe (Europe of representative value 4000), the Europe of output impedance 4000~6000 (Europe of representative value 5000)；4. full scale temperature is accurate
Exactness -1.0~1.0%FSO, zero temperature -1.25~1.25%FSO of accuracy；5. stability 5uV/V, opens from nearly 0.01Hz
Beginning to 2KHz range of frequencies, it is flat to respond, and the respiratory waveform of piezoresistive transducer measurement is more preferable than piezoelectric transducer fidelity.
NPC1210 is widely used in armarium, respirator, air flow context of detection；The low pressure sensor of NPC1210 series is one
The product of money comparative maturity.
The structure of the piezoresistive pressure sensor 4 is the wheatstone bridge configuration of 4 p-type resistance compositions, the p-type electricity
Resistance is internal semiconductor membrane.Constant current source power supply circuit 6 of the present invention is connected to into+IN the inputs of the piezoresistive pressure sensor
Between end and-IN inputs.NPC1210 series low pressure sensors adopt constant current source power supply, its internal main knot mentioned above
The wheatstone bridge configuration that structure is made up of strain diaphragm.When powering compared to constant pressure source, the sensor of wheatstone bridge configuration
During using constant current source power supply, sensor output voltage is only linear with the increment of membrane resistance and constant-current source size of current,
Temperature, sensor accuracy etc. will not be subject to affect, therefore the stability of sensor output is higher.
The precision of sensor and the acquisition precision of signal are directly influenced due to the quality of constant-current source, it is therefore desirable to select altogether
The amplifier of good performance such as mould rejection ratio, temperature coefficient, dc noise.That operational amplifier therein is selected is Analog
The AD823AR of Device companies production.
From the figure 3, it may be seen that operational amplifier in-phase end (being U1) identical with the magnitude of voltage of end of oppisite phase, through sensor
The electric current I sizes of NPC1210 by being determined by stabilivolt D1 voltage stabilizing values (U1-VSS) and resistance R2 resistances, i.e.,：
Resistance R2 selects the metal film precision resistance of 2.0k Ω, model 1N4736_3V0 of stabilivolt D1, voltage stabilizing value
3.0V.The constant current source size of generation is 1.5mA.
Although above in conjunction with accompanying drawing, invention has been described, the invention is not limited in above-mentioned being embodied as
Mode, above-mentioned specific embodiment is only schematic, rather than restricted, and one of ordinary skill in the art is at this
Under the enlightenment of invention, without deviating from the spirit of the invention, many variations can also be made, these belong to the present invention's
Within protection.
Claims (4)
1. a kind of constant current source power supply circuit of the breath signal sensor based on air fluidized bed, wherein, breath signal is adopted by sensor
Collection, the structure of the sensor is the wheatstone bridge configuration of 4 p-type resistance compositions, has semiconductor film inside the p-type resistance
Piece, it is characterised in that：
Constant current source power supply circuit includes operational amplifier, resistance R1, resistance R2, Zener diode D1 and electric capacity C1, the sensing
+ IN the inputs of device are connected with the outfan of operational amplifier, the in-phase input end of the operational amplifier simultaneously with the electricity
- IN inputs the connection of one end, the negative electrode of the Zener diode D1 and the sensor of resistance R1, the resistance R1's is another
End is connected to supply voltage, and the inverting input of the operational amplifier is connected by the resistance R2 with ground voltage, described
The anode of Zener diode D1 is connected with one end of the electric capacity C1 and ground voltage simultaneously, another termination of the electric capacity C1
Ground.
2. the constant current source power supply circuit of the breath signal sensor of air fluidized bed is based on according to claim 1, it is characterised in that
The operational amplifier selects AD823AR operational amplifiers.
3. the constant current source power supply circuit of the breath signal sensor of air fluidized bed is based on according to claim 1, it is characterised in that
Metal film precision resistances of the resistance R2 from 2.0k Ω.
4. the constant current source power supply circuit of the breath signal sensor of air fluidized bed is based on according to claim 1, it is characterised in that
Model 1N4736_3V0 of the Zener diode D1, its voltage stabilizing value is 3.0V, and the constant current source size of generation is 1.5mA.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410768774.9A CN104516387B (en) | 2014-12-12 | 2014-12-12 | Constant flow source supply circuit of respiration signal sensor based on air cushion bed |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410768774.9A CN104516387B (en) | 2014-12-12 | 2014-12-12 | Constant flow source supply circuit of respiration signal sensor based on air cushion bed |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104516387A CN104516387A (en) | 2015-04-15 |
| CN104516387B true CN104516387B (en) | 2017-05-17 |
Family
ID=52791856
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410768774.9A Active CN104516387B (en) | 2014-12-12 | 2014-12-12 | Constant flow source supply circuit of respiration signal sensor based on air cushion bed |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104516387B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070113665A1 (en) * | 2005-11-10 | 2007-05-24 | Honeywell International Inc. | Pressure and temperature sensing element |
| CN201293698Y (en) * | 2008-12-02 | 2009-08-19 | 西安中星测控有限公司 | Pressure transmitter with temperature compensation circuit |
| CN201382913Y (en) * | 2009-02-19 | 2010-01-13 | 哈尔滨东方报警设备开发有限公司 | Gas detector with sensor over concentration protection |
| CN203323928U (en) * | 2013-06-27 | 2013-12-04 | 无锡信大气象传感网科技有限公司 | Piezoresistive pressure transmitter |
| CN204536969U (en) * | 2014-12-12 | 2015-08-05 | 天津大学 | A kind of constant current source power supply circuit of the breath signal sensor based on air bed |
-
2014
- 2014-12-12 CN CN201410768774.9A patent/CN104516387B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070113665A1 (en) * | 2005-11-10 | 2007-05-24 | Honeywell International Inc. | Pressure and temperature sensing element |
| CN201293698Y (en) * | 2008-12-02 | 2009-08-19 | 西安中星测控有限公司 | Pressure transmitter with temperature compensation circuit |
| CN201382913Y (en) * | 2009-02-19 | 2010-01-13 | 哈尔滨东方报警设备开发有限公司 | Gas detector with sensor over concentration protection |
| CN203323928U (en) * | 2013-06-27 | 2013-12-04 | 无锡信大气象传感网科技有限公司 | Piezoresistive pressure transmitter |
| CN204536969U (en) * | 2014-12-12 | 2015-08-05 | 天津大学 | A kind of constant current source power supply circuit of the breath signal sensor based on air bed |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104516387A (en) | 2015-04-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Van de Water et al. | Objective measurements of sleep for non‐laboratory settings as alternatives to polysomnography–a systematic review | |
| CN104665834A (en) | Sleeping respiration signal acquiring device based on air bed | |
| Nielsen et al. | Lung function response to cold air challenge in asthmatic and healthy children of 2–5 years of age | |
| Al-Matary et al. | Increased peripheral chemoreceptor activity may be critical in destabilizing breathing in neonates | |
| CN105748069B (en) | A kind of centric sleep apnea carbon dioxide inhalation therapy device | |
| KR20100022706A (en) | Apparatus and method for non-constrained analysis of sleeping status using air-mattress | |
| JPH10510726A (en) | Internal recording of gas / air and other fluid flows in the human body and use of pressure sensors for recording | |
| Chokroverty et al. | Polysomnographic recording technique | |
| Sands et al. | New approaches to diagnosing sleep-disordered breathing | |
| Chen et al. | A pervasive respiratory monitoring sensor for COVID-19 pandemic | |
| WO2013003841A1 (en) | Whole-body pletysmography system for the continuous characterization of sleep and breathing in a mouse | |
| CN204536969U (en) | A kind of constant current source power supply circuit of the breath signal sensor based on air bed | |
| CN104516387B (en) | Constant flow source supply circuit of respiration signal sensor based on air cushion bed | |
| CN204318758U (en) | A kind of sleep-respiratory signal pickup assembly based on air fluidized bed | |
| CN205625901U (en) | Mental health monitored control system based on cloud data platform | |
| Hernandez et al. | A new non-invasive approach for monitoring respiratory movements of sleeping subjects | |
| de Melo et al. | Instrumentation for the analysis of respiratory system disorders during sleep: design and application | |
| Teixeira et al. | Instrumentation for the analysis of airflow limitation by the negative expiratory pressure technique | |
| TWI669104B (en) | System for detecting apnea-related physiological signal | |
| Itakura et al. | Effect of body position on tidal volume and minute ventilation in very low birthweight infants | |
| CN205658895U (en) | Portable sleep monitor equipment | |
| CN114027824B (en) | Construction method and application of linear model of universal pulmonary ventilation and transthoracic electrical impedance | |
| CN207679453U (en) | A kind of device for treating centric sleep apnea disease | |
| Yunfeng et al. | Fabrication and Characterization of Yarn-Based Temperature Sensor for Respiratory Monitoring. | |
| CN212281332U (en) | Breath analyzer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |