CN102156805B - External chest compression physiological feedback signal simulator - Google Patents

Abstract

The invention discloses an external chest compression physiological feedback signal simulator, which comprises a displacement sampling module, a keyboard, a microcontroller and a liquid crystal display screen, wherein the microcontroller receives external chest compression depth signals from the displacement sampling module and processes the signals into corresponding external chest compression depth data, the microcontroller acquires external chest compression frequency data by calculating the periodical change times of the external chest compression depth signals in unit time, and the microcontroller also receives chest pump factor data and safety range data from the keyboard; and the microcontroller processes the external chest compression depth data, the external chest compression frequency data, the chest pump factor data and the safety range data based on an external chest compression feedback physiological signal simulation model through corresponding simulation algorithm programs to acquire coronary perfusion pressure simulation data, mean arterial relaxation pressure simulation data and end-tidal carbon dioxide partial pressure simulation data. The simulator can be used for first-aid training, and fulfills the purpose of improving the external chest compression efficiency by adopting a personalized first-aid scheme.

Description

Chest compression physiological feedback signal simulator

Technical field

The present invention relates to a kind of medical science physiology signal simulator, particularly relate to a kind of chest compression physiological feedback signal simulator.

Background technology

Rescue sudden cardiac arrest patient, usually take the external chest compression first-aid method.The fundamental purpose of external chest compression is for the human body vitals such as brain and heart in time provide blood supply, impels blood of human body rebuliding from major cycle.Therefore, in the first aid process, the volume of blood flow of blood circulation of human body is to estimate the core index of external chest compression quality.In the first aid process, the physiological parameter relevant to the blood circulation of human body volume of blood flow (such as Coronary Perfusion Pressure, End-tidal carbon dioxide dividing potential drop and average auterial diastole are pressed) is the core index of estimating the external chest compression quality.We are with Coronary Perfusion Pressure (Coronary Perfusion Pressure, CPP), End-tidal carbon dioxide dividing potential drop (Pressure of End-Tidal CO ₂, PETCO2) press (Mean Arterial Relaxation Pressure, MARP) these physiological signals that can react the external chest compression quality to be referred to as external chest compression physiological feedback signal with average auterial diastole.

Studies show that in a large number, CPP, PETCO2 and MARP and patient's cardiopulmonary resuscitation volume of blood flow and autonomous cyclic reconstruction effect have close ties.CPP is as the main drive of coronary perfusion blood flow, has great correlativity with patient's MBF with from the foundation of major cycle.Only in the situation that CPP greater than 15mmHg, just might rebulid autonomous blood circulation.The assessment experiment of lot of domestic and foreign external chest compression all with it as the core evaluation index, regard it as the goldstandard of estimating the external chest compression quality.Simultaneously, American Heart Association's cardiopulmonary resuscitation in 2010 and emergency cardiovascular care guide proposed with PETCO2 and MARP as estimate the external chest compression quality without wound and the wound index is arranged, clear and definite in the situation that PETCO2 attempts improving the requirement of external chest compression quality less than 20mmHg less than 10mmHg or at MARP.

At present, in the training on operation of first-aid personnel's external chest compression, all only will be according to pressing depth with the unitized standard of frequency as evaluation index, in the process of suing and labouring, chest compression depth and frequency to different patients are unitized, although be conducive to the first-aid personnel to the grasp of external chest compression, facilitate its operation, but ignored patient's individual difference.Difference due to patient's build, chest thickness, pressing position and health status, the external chest compression of same standard depth and frequency will produce to different patients different blood circulation of human body volume of blood flow, and the first aid effect that causes some patient is carried out external chest compression is not good even invalid.For the different situations for the patient adopt personalized first aid scheme, to improve external chest compression efficient, just must the physiological parameter relevant to patient's volume of blood flow be fullyed understand, thus the external chest compression operation that provides more effective, satisfies the actual physiological conditions of patient.

Therefore, the crucial physiological feedback signal of analog simulation external chest compression, the first-aid personnel is understood all-sidedly and accurately from the physiological change angle of patient own grasp the external chest compression quality, thereby the effective external chest compression operation that meets the actual physiological conditions of patient is provided, all significant to improving external chest compression first aid quality and cardiopulmonary resuscitation first aid quality.

At present, do not find that both at home and abroad this type of can analog simulation sudden cardiac arrest patient Coronary Perfusion Pressure, average auterial diastole during external chest compression presses and document and the product of End-tidal carbon dioxide dividing potential drop.

Summary of the invention

The present invention provides a kind of chest compression physiological feedback signal simulator for solving the technical matters that exists in known technology.

The technical scheme that the present invention takes for the technical matters that exists in the solution known technology is: a kind of chest compression physiological feedback signal simulator, comprise displacement sampling module, keyboard, microcontroller, LCDs, wherein:

The collection of described displacement sampling module detects the chest compression depth signal that obtains from displacement transducer;

Described keyboard is used for arranging the safe range data of concrete chest pump factor data and external chest compression physiological feedback signal;

Described microcontroller receives from the described chest compression depth signal of described displacement sampling module and is treated to and can supply the corresponding chest compression depth data of microcontroller computing, described chest compression depth signal period property change frequency in time obtains external chest compression compression frequency data to described microcontroller by unit of account, and described microcontroller also receives from the chest pump factor data of keyboard and safe range data; Described microcontroller is based on external chest compression feedback physiological signal analog simulation model, by corresponding simulation algorithm program, described chest compression depth data, external chest compression frequency data, chest pump factor data and safe range data are processed, obtained Coronary Perfusion Pressure emulated data, average auterial diastole pressure emulated data and End-tidal carbon dioxide dividing potential drop emulated data;

Described LCDs shows the following data from described microcontroller: chest pump factor data, chest compression depth data, external chest compression frequency data, Coronary Perfusion Pressure emulated data, average auterial diastole are pressed emulated data, End-tidal carbon dioxide dividing potential drop emulated data.

Advantage and good effect that the present invention has are: can the analog simulation sudden cardiac arrest patient CPP, MARP in the external chest compression process and PETCO2 these can react the crucial physiological feedback signal of external chest compression quality.By regulating the chest pump factor, can the external chest compression physiological feedback signal of analog simulation patient under different chest pump mechanism and heart pump mechanism reciprocation.These external chest compression physiological feedback signals can show by LCDs, and with the form of simulating signal or digital signal for the collection of external signal sample devices.Simultaneously, when exceeding predetermined alarm range, simulator can produce sound and light alarm.In addition, simulator can be stored the crucial physiological feedback signal simulated data of external chest compression overall process, for later analysis.The present invention can be used for the first aid of cardiopulmonary resuscitation, Coronary Perfusion Pressure, average auterial diastole by accurate analog simulation under different external chest compression operations are pressed and the End-tidal carbon dioxide dividing potential drop, the first-aid personnel can fully understand affects the physiological feedback signal of the autonomous cyclic reconstruction of patient situation of change, grasp the external chest compression quality more objective and accurately, break through generally adopt at present to unify chest compression depth and frequency as the limitation of standard evaluation external chest compression quality, reach the essential purpose that adopts personalized first aid scheme to improve external chest compression efficient.

Description of drawings

Fig. 1 is hardware block diagram of the present invention;

Fig. 2 is external chest compression physiological feedback signal analog simulation model structure block diagram of the present invention;

Fig. 3 is the blood circulation of human body illustraton of model;

Fig. 4 is thoracic cavity blood-circulation model figure.

Embodiment

For further understanding summary of the invention of the present invention, Characteristic, hereby exemplify following examples, and coordinate accompanying drawing to be described in detail as follows:

See also Fig. 1, Fig. 1 is chest compression physiological feedback signal simulator hardware block diagram of the present invention, and this simulator utilizes the displacement sampling module to gather the chest compression depth signal; The safe range of concrete chest pump factor values and external chest compression physiological feedback signal is set by keyboard, and these data and signal are real-time transmitted to microcontroller.The analog to digital converter collection of microcontroller inside is from the chest compression depth signal of displacement sampling module, and converts the CPU that digital quantity sends microcontroller to, carries out calculation process by CPU.Simultaneously, microcontroller obtains chest and presses compression frequency by the chest compression depth signal period property change frequency in the unit of account time.The comprehensive chest compression depth of microcontroller, external chest compression frequency and the chest pump factor, and in conjunction with the algorithm routine of writing according to external chest compression feedback physiological signal analog simulation model, obtain the analog simulation data of current Coronary Perfusion Pressure, average auterial diastole pressure and End-tidal carbon dioxide dividing potential drop.These emulated datas by external interface in the mode of simulating signal or digital signal for the collection of external sampling equipment.Simultaneously, microcontroller drives LCDs and shows the chest compression physiological feedback data, and the driving loudspeaker sends alerting signal when emulated data exceeds default safe range.In addition, microcontroller by peripheral memory store in the external chest compression process according to pressing depth, compression frequency, the chest pump factor and external chest compression physiological feedback signal, for later analysis.

See also Fig. 2, Fig. 2 is external chest compression physiological feedback signal analog simulation model structure block diagram of the present invention.Wherein each several part formation and function introduction are as follows:

The mode input parameter:

Chest compression depth and external chest compression frequency: chest compression depth detects by the displacement sampling module and obtains, and the chest compression depth signal period property change frequency in the time obtains the external chest compression frequency by unit of account by microcontroller.

The chest pump factor: the external chest compression mechanism of action exists chest pump mechanism and two kinds of explanations of heart pump mechanism.Utilize the chest pump factor, accurately the different patient's external chest compression of analogue simulation chest pump mechanism and heart pump mechanism interaction effect.The pressure that acts on vertical diaphragm equals to indulge the product of diaphragm pressure P M and the chest pump factor.When the chest pump factor is 0, be pure heart pumping action, in the case, as opening the chest external chest compression, press pressure only acts on left ventricle and right ventricle; When the chest pump factor is 1, be pure chest pumping action, in the case, all vertical diaphragm structures comprise that vena cava and aorta pectoralis all are subject to the effect of intrathoracic pressure.In fact, external chest compression is the result of chest pump mechanism and the machine-processed combined action of heart pump, the chest pump factor of human body and animal between 0 and 1, the individuality of different builds, or same individuality has the different chest pump factors under different physiological statuss.Crucial physiological feedback signal and the chest pump factor of the reaction external chest compression quality such as CPP, PETCO2 and MARP have direct relation, namely identical according to pressing depth with the external chest compression effect situation of frequency under, the chest pump factor directly has influence on the physiological feedback signal of the reaction external chest compression quality such as CPP, PETCO2 and MARP.

Cardiopulmonary resuscitation blood circulation module:

Cardiopulmonary resuscitation blood circulation module is made of 14 vasculars and organ submodule, be the fluid damping path between each submodule, blood flow circulates through the overdamping path, see also Fig. 3 and Fig. 4, Fig. 3 is the blood circulation of human body illustraton of model, and in the analogue body circulation, blood flow circulates through the damping path of corresponding vascular and organ.Fig. 4 is thoracic cavity blood-circulation model figure, and in the simulated lung circulation, blood flow circulates through the damping path of corresponding vascular and organ.In figure, the definition of designation and subscript is as shown in table 1.The normal adult male sex that in model, the physiological parameter such as the compliance C of each vascular and organ and fluid damping R is all 70kg from a body weight, concrete physiological parameter numerical value can obtain by consulting the relevant physiological anatomic data.

Table 1:

Cardiopulmonary resuscitation blood-circulation model hemodynamics principle can use formula (1)-(2) to describe.

C＝ΔV/ΔP (1)

I＝(1/R)(P ₁-P ₂) (2)

Formula (1) is compliance concept formula, and wherein C is the tube chamber amount of complying with, and Δ P is the pressure variety that makes capacity of blood vessel changes delta V.Formula (2) is the Ohm law formula, and wherein I is the volume of blood flow in the unit interval, P ₁-P ₂For acting on the pressure differential on vascular and organ damping R.This pressure differential acts on R, and producing size within the unit interval is the volume of blood flow of I.Arrow in Fig. 2,3 indicated in the body circulation blood positive flow between each vascular and organ to.

In order reasonably to describe chest compression physiological mechanism, press and indulge diaphragm and press sum for lung the effective pressure value in the external chest compression process is abstract, with formula (3)-(5) expression.

P _c＝P _lung+f _tpP _m (0≤f _tp≤1) (3)

$P_M=\frac{E}{d_0}\max (0,x-2)---\left(4\right)$

P _lung＝(ΔV _chest+V _in-V _out)/C _lung (5)

Formula (3) is external chest compression effective pressure defined formula, wherein P _cBe external chest compression effective pressure, P _LungAnd P _MBe respectively the lung pressure and the vertical diaphragm pressure that are caused by external chest compression, f _tpBe the chest pump factor.With vertical diaphragm abstract be a resilient material that elastic modulus is E, vertical diaphragm pressure P _MFor the product of vertical diaphragm elastic modulus E and stress, as shown in formula (4), wherein x is for according to pressing depth, d ₀Be chest anteroposterior diameter thickness.Formula (4) has reflected effectively according to pressing depth threshold effect.Studies show that, according to pressing depth lower than a certain threshold X ₀The time, cardiac output is almost nil; Only have according to pressing depth greater than threshold X ₀The time, cardiac output just can begin to increase.Therefore, only have according to pressing depth greater than X ₀, external chest compression could produce effectively vertical diaphragm pressure.In the cardiopulmonary resuscitation blood-circulation model, X ₀=2cm.Formula (5) is pressed P for lung _LungDefined formula, wherein Δ V _ChestBe the change amount of lung volume in the external chest compression process, V _in-V _outBe the long-pending change amount of lung network capacity, C _LungBe the overall comprehensive compliance of chest lung.

On formula (1)-(5) basis, set up one group of hemodynamic finite difference equation, described respectively 14 vascular organs at the instantaneous pressure value of different time points, as follows, in formula (6)-(19), the definition of designation and subscript is as shown in table 1.

${\mathrm{\ΔV}}_{\mathrm{aa}}=(i_a-i_s-i_{\mathrm{ia}})\mathrm{\Δt}=[\frac{P_{\mathrm{ao}}-P_{\mathrm{aa}}}{R_a}-\frac{P_{\mathrm{aa}}-P_{\mathrm{ivc}}}{R_s}-\frac{P_{\mathrm{aa}}-P_{\mathrm{fa}}}{R_{\mathrm{ia}}}]\mathrm{\Δt}---\left(6\right)$

$\mathrm{\Δ}{P}_{\mathrm{aa}}=\frac{\mathrm{\Δ}{V}_{\mathrm{aa}}}{C_{\mathrm{aa}}}$

Wherein Δ t is the sample unit time, Δ V _aaCapacity of blood vessel increment for the abdomen artery within the Δ t time, Δ P _aaBe abdomen arterial pressure increment in the Δ t time.In like manner can get following formula.

$\mathrm{\Δ}{V}_{\mathrm{ivc}}=(i_s-i_v+i_{\mathrm{fv}})\mathrm{\Δt}=[\frac{P_{\mathrm{aa}}-P_{\mathrm{ivc}}}{R_s}-\frac{P_{\mathrm{ivc}}-P_{\mathrm{ra}}}{R_v}+\max (0,\frac{P_{\mathrm{fv}}-P_{\mathrm{ivc}}}{R_{\mathrm{iv}}})]\mathrm{\Δt}---\left(7\right)$

$\mathrm{\Δ}{P}_{\mathrm{ivc}}=\frac{\mathrm{\Δ}{V}_{\mathrm{ivc}}}{C_{\mathrm{ivc}}}$

Wherein, max () function is maximal value value function.

$\mathrm{\Δ}{P}_{\mathrm{car}}=\frac{1}{C_{\mathrm{car}}}(i_c-i_h)\mathrm{\Δt}=\frac{\mathrm{\Δt}}{C_{\mathrm{car}}}[\frac{P_{\mathrm{ao}}-P_{\mathrm{car}}}{R_c}-\frac{P_{\mathrm{car}}-P_{\mathrm{jug}}}{R_h}]---\left(8\right)$

$\mathrm{\Δ}{P}_{\mathrm{jug}}=\frac{1}{C_{\mathrm{jug}}}(i_h-i_j)\mathrm{\Δt}=\frac{\mathrm{\Δt}}{C_{\mathrm{jug}}}[\frac{P_{\mathrm{car}}-P_{\mathrm{jug}}}{R_h}-\max (0,\frac{P_{\mathrm{jug}}-P_{\mathrm{ra}}}{R_j})]---\left(9\right)$

$\mathrm{\Δ}{P}_{\mathrm{fa}}=\frac{1}{C_{\mathrm{fa}}}(i_{\mathrm{ia}}-i_l)\mathrm{\Δt}=\frac{\mathrm{\Δt}}{C_{\mathrm{fa}}}[\frac{P_{\mathrm{aa}}-P_{\mathrm{fa}}}{R_{\mathrm{ia}}}-\frac{P_{\mathrm{fa}}-P_{\mathrm{fv}}}{R_l}]---\left(10\right)$

$\mathrm{\Δ}{P}_{\mathrm{fv}}=\frac{1}{C_{\mathrm{fv}}}(i_l-i_{\mathrm{fv}})\mathrm{\Δt}=\frac{\mathrm{\Δt}}{C_{\mathrm{fv}}}[\frac{P_{\mathrm{fa}}-P_{\mathrm{fv}}}{R_l}-\max (0,\frac{P_{\mathrm{fv}}-P_{\mathrm{ivc}}}{R_{\mathrm{iv}}})]---\left(11\right)$

$\mathrm{\Δ}{P}_{\mathrm{ppa}}=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δt}}{C_{\mathrm{ppa}}}(i_3-i_4)=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δt}}{C_{\mathrm{ppa}}}[\frac{P_{\mathrm{pa}}-P_{\mathrm{ppa}}}{R_{\mathrm{cppa}}}-\frac{P_{\mathrm{ppa}}-P_{\mathrm{ppv}}}{R_{\mathrm{pc}}}]---\left(12\right)$

$\mathrm{\Δ}{P}_{\mathrm{ppv}}=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δt}}{C_{\mathrm{ppv}}}(i_4-i_5)=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δt}}{C_{\mathrm{ppv}}}[\frac{P_{\mathrm{ppa}}-P_{\mathrm{ppv}}}{R_{\mathrm{pc}}}-\frac{P_{\mathrm{ppv}}-P_{\mathrm{la}}}{R_{\mathrm{cppv}}}]---\left(13\right)$

${\mathrm{\ΔV}}_{\mathrm{ao}}=(i_o-i_c-i_a-i_{\mathrm{ht}})\mathrm{\Δt}=[\max (0,\frac{P_{\mathrm{lv}}-P_{\mathrm{ao}}}{R_{\mathrm{av}}})-\frac{P_{\mathrm{ao}}-P_{\mathrm{car}}}{R_c}-\frac{P_{\mathrm{ao}}-P_{\mathrm{aa}}}{R_a}-\frac{P_{\mathrm{ao}}-P_{\mathrm{ra}}}{R_{\mathrm{ht}}}]\mathrm{\Δt}---\left(14\right)$

$\mathrm{\Δ}{P}_{\mathrm{ao}}=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δ}{V}_{\mathrm{ao}}}{C_{\mathrm{ao}}}+f_{\mathrm{tp}}\frac{E}{d_0}\mathrm{\Δx}$

Wherein Δ x is the chest compression depth variable quantity in the Δ t time, i.e. breastbone displacement increment.

$\mathrm{\Δ}{V}_{\mathrm{pa}}=(i_2-i_3)\mathrm{\Δt}=[\max (0,\frac{P_{\mathrm{rv}}-P_{\mathrm{pa}}}{R_{\mathrm{pv}}})-\frac{P_{\mathrm{pa}}-P_{\mathrm{ppa}}}{R_{\mathrm{cppa}}}]\mathrm{\Δt}---\left(15\right)$

$\mathrm{\Δ}{P}_{\mathrm{pa}}=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δ}{V}_{\mathrm{pa}}}{C_{\mathrm{pa}}}+f_{\mathrm{tp}}\frac{E}{d_0}\mathrm{\Δx}$

${\mathrm{\ΔV}}_{\mathrm{ra}}=(i_j+i_v+i_{\mathrm{ht}}-i_i)\mathrm{\Δt}=[\max (0,\frac{P_{\mathrm{jug}}-P_{\mathrm{ra}}}{R_j})+\frac{P_{\mathrm{ivc}}-P_{\mathrm{ra}}}{R_v}+\frac{P_{\mathrm{ao}}-P_{\mathrm{ra}}}{R_{\mathrm{ht}}}-\max (0,\frac{P_{\mathrm{ra}}-P_{\mathrm{rv}}}{R_{\mathrm{tv}}})]\mathrm{\Δt}$

$\mathrm{\Δ}{P}_{\mathrm{ra}}=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δ}{V}_{\mathrm{ra}}}{C_{\mathrm{ra}}}+f_{\mathrm{tp}}\frac{E}{d_0}(\mathrm{\Δx}+\frac{\mathrm{\Δ}{V}_{\mathrm{ra}}}{A_{\mathrm{ra}}})---\left(16\right)$

${\mathrm{\ΔV}}_{\mathrm{rv}}=(i_i-i_2)\mathrm{\Δt}=[\max (0,\frac{P_{\mathrm{ra}}-P_{\mathrm{rv}}}{R_{\mathrm{tv}}})-\max (0,\frac{P_{\mathrm{rv}}-P_{\mathrm{pa}}}{R_{\mathrm{pv}}})]\mathrm{\Δt}---\left(17\right)$

$\mathrm{\Δ}{P}_{\mathrm{rv}}=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δ}{V}_{\mathrm{rv}}}{C_{\mathrm{rv}}}+\frac{E}{d_0}(\mathrm{\Δx}+\frac{\mathrm{\Δ}{V}_{\mathrm{rv}}}{A_{\mathrm{rv}}})$

$\mathrm{\Δ}{V}_{\mathrm{la}}=[\frac{P_{\mathrm{ppv}}-P_{\mathrm{la}}}{R_{\mathrm{cppv}}}-\max (0,\frac{P_{\mathrm{la}}-P_{\mathrm{lv}}}{R_{\mathrm{mv}}})]\mathrm{\Δt}---\left(18\right)$

$\mathrm{\Δ}{P}_{\mathrm{la}}=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δ}{V}_{\mathrm{la}}}{C_{\mathrm{la}}}+f_{\mathrm{tp}}\frac{E}{d_0}(\mathrm{\Δx}+\frac{\mathrm{\Δ}{V}_{\mathrm{la}}}{A_{\mathrm{la}}})$

${\mathrm{\ΔV}}_{\mathrm{lv}}=(i_6-i_o)\mathrm{\Δt}=[\max (0,\frac{P_{\mathrm{la}}-P_{\mathrm{lv}}}{R_{\mathrm{mv}}})-\max (0,\frac{P_{\mathrm{lv}}-P_{\mathrm{ao}}}{R_{\mathrm{av}}})]\mathrm{\Δt}---\left(19\right)$

$\mathrm{\Δ}{P}_{\mathrm{lv}}=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δ}{V}_{\mathrm{lv}}}{C_{\mathrm{lv}}}+\frac{E}{d_0}(\mathrm{\Δx}+\frac{\mathrm{\Δ}{V}_{\mathrm{lv}}}{A_{\mathrm{lv}}})$

In module, the current pressure value of 14 vasculars and organ module is force value and the unit interval internal pressure increment sum of previous time point, as shown in formula (20).

P(t+Δt)＝P(t)+ΔP(t) (20)

The selection in sampling time directly has influence on the quality of simulation result.The excessive sampling time will cause the blood pressure simulation result to produce unstable oscillation; Sampling time is less, and analogue system is more stable.Here we are taken as 0.001s with sampling time Δ t.For the blood pressure situation of emulation sudden cardiac arrest patient, the initial pressure value unification of 14 vasculars and organ module is set to 10mmHg.

The CPP emulation module:

The CPP emulation module utilizes IAP diastolic pressure and right atrial pressure diastolic pressure to try to achieve current real-time CPP value.Concrete grammar is as follows: CPP is the mean value of aorta pectoralis diastolic pressure and atrium dextrum diastolic pressure difference.A large amount of researchists define according to this, summed up the CPP computing method: wish is calculated a CPP who presses the cycle, at first needs to obtain the area sum A between interior each the sample unit time aorta pectoralis blood pressure of a diastole (decompression phase) and atrium dextrum blood pressure curve _cppCPP namely equals A _cppDivided by diastole (decompression phase) duration, as shown in formula (21).

$\mathrm{CPP}=\frac{2\underset{t=T/2}{\overset{T}{\mathrm{\Σ}}}\left(\right|P_{\mathrm{ao}}\left(t\right)-P_{\mathrm{ra}}\left(t\right)\left|\mathrm{\Δt}\right)}{T}---\left(21\right)$

In formula (21), T is an external chest compression cycle, and Δ t is the sample unit time, P _ao(t) and P _ra(t) be respectively t aorta pectoralis blood pressure and atrium dextrum blood pressure constantly.We are made as whole half of cycle length of pressing at time phase of reducing pressure.

The MARP emulation module:

The MARP emulation module as input, is tried to achieve IAP the thorax artery pressing average of an external chest compression in diastole and is namely obtained MARP.Concrete grammar is as follows: it is within an external chest compression decompression phase that average auterial diastole is pressed MARP, the mean value of IAP, namely equal within a diastole (decompression phase) the IAP area under curve divided by diastole (decompression phase) duration, as shown in formula (22).

$\mathrm{MARP}=\frac{2\underset{t=T/2}{\overset{T}{\mathrm{\Σ}}}\left(P_{\mathrm{ao}}\left(t\right)\mathrm{\Δt}\right)}{T}---\left(22\right)$

In formula (22), T is an external chest compression cycle, and Δ t is the sample unit time, P _ao(t) be t IAP constantly.Equally, we are made as whole half of cycle length of pressing at time phase of reducing pressure.

The CPP-PETCO2 relational model:

A large amount of clinical researches show that the CPP of human body and PETCO2 have stronger linear dependence, and by analysis and summary, it is as follows that we obtain CPP and the PETCO2 linear relationship equation of human body:

PETCO2＝0.465×CPP+3.279 (23)

The CPP that the utilization of CPP-PETCO2 relational model has been tried to achieve can analog simulation current PE TCO2 by the relation formula of CPP and PETCO2.

The present invention has following advantage:

1) utilize imitation technology accurate simulation patient to reflect the crucial physiological signal of external chest compression quality under different external chest compression effects, make the first aid student can be from the more objective external chest compression quality of grasping all sidedly of the physiological status angle of patient own, break through generally adopt at present to unify chest compression depth and frequency as the limitation of standard evaluation external chest compression quality;

2) when the simulation external chest compression physiological feedback signal exceeds default safe range, the simulator automatic alarm reminds the first aid student in time to improve the external chest compression operation;

3) realize external chest compression physiological feedback signal simulated data record and the storage of external chest compression overall process, be convenient to analyzing and processing in the future;

4) provide numeral or simulating signal Sampling Interface, the collection of convenient various sample devicess is used;

5) have chest pump factor regulatory function, the relevant physiological signal of analog simulation patient under different chest pumps and heart pump mechanism reciprocation, make the analog simulation result truer as requested.

Although the above is described the preferred embodiments of the present invention by reference to the accompanying drawings; but the present invention is not limited to above-mentioned embodiment; above-mentioned embodiment is only schematic; be not restrictive; those of ordinary skill in the art is under enlightenment of the present invention; not breaking away from the scope situation that aim of the present invention and claim protect, can also make a lot of forms, within these all belong to protection scope of the present invention.

Claims (9)

1. a chest compression physiological feedback signal simulator, is characterized in that, comprises displacement sampling module, keyboard, microcontroller, LCDs, wherein:

The collection of described displacement sampling module detects the chest compression depth signal that obtains from displacement transducer;

Described keyboard is used for arranging the safe range data of concrete chest pump factor data and external chest compression physiological feedback signal;

Described microcontroller receives from the described chest compression depth signal of described displacement sampling module and is treated to and can supply the corresponding chest compression depth data of microcontroller computing, described chest compression depth signal period property change frequency in time obtains the external chest compression frequency data to described microcontroller by unit of account, and described microcontroller also receives from the chest pump factor data of keyboard and safe range data; Described microcontroller is based on external chest compression feedback physiological signal analog simulation model, described chest compression depth data, external chest compression frequency data, chest pump factor data and safe range data are processed, obtained Coronary Perfusion Pressure emulated data, average auterial diastole pressure emulated data and End-tidal carbon dioxide dividing potential drop emulated data;

Described LCDs shows the following data from described microcontroller: chest pump factor data, chest compression depth data, external chest compression frequency data, Coronary Perfusion Pressure emulated data, average auterial diastole are pressed emulated data, End-tidal carbon dioxide dividing potential drop emulated data;

Described external chest compression feedback physiological signal analog simulation model comprises:

Cardiopulmonary resuscitation blood circulation emulation module, consisted of by 14 vasculars and organ submodule, described 14 vasculars and organ submodule are: abdominal cavity main artery, aorta pectoralis, arteria carotis, femoral artery, femoral vein, bone artery, bone vein, inferior caval vein, jugular vein, center pulmonary artery, periphery pulmonary artery, periphery pulmonary vein, atrium dextrum and right ventricle, be the fluid damping path between each submodule, blood flow circulates through the overdamping path; Described cardiopulmonary resuscitation blood circulation emulation module produces described 14 vasculars and organ submodule in the instantaneous blood pressure emulated data of different time points, comprising: IAP and right atrial pressure emulated data;

Coronary Perfusion Pressure emulation module, input produce the Coronary Perfusion Pressure emulated data from IAP and the right atrial pressure emulated data of cardiopulmonary resuscitation blood circulation emulation module;

Average auterial diastole is pressed emulation module, and input produces average auterial diastole and presses emulated data from the IAP of cardiopulmonary resuscitation blood circulation emulation module;

Coronary Perfusion Pressure-End-tidal carbon dioxide dividing potential drop concerns emulation module, and input produces End-tidal carbon dioxide dividing potential drop emulated data from the Coronary Perfusion Pressure emulated data of Coronary Perfusion Pressure emulation module.

2. chest compression physiological feedback signal simulator according to claim 1, it is characterized in that, described cardiopulmonary resuscitation blood circulation emulation module calls one group of hemodynamic finite difference equation, described respectively 14 vasculars and organ at the instantaneous pressure value of different time points, described finite difference equation comprises:

$\mathrm{\Δ}{V}_{\mathrm{aa}}=(i_a-i_s-i_{\mathrm{ia}})\mathrm{\Δt}=[\frac{P_{\mathrm{ao}}-P_{\mathrm{aa}}}{R_a}-\frac{P_{\mathrm{aa}}-P_{\mathrm{ivc}}}{R_s}-\frac{P_{\mathrm{aa}}-P_{\mathrm{fa}}}{R_{\mathrm{ia}}}]\mathrm{\Δt}$

$\mathrm{\Δ}{P}_{\mathrm{aa}}=\frac{\mathrm{\Δ}{V}_{\mathrm{aa}}}{C_{\mathrm{aa}}}$

$\mathrm{\Δ}{V}_{\mathrm{ivc}}=(i_s-i_v-i_{\mathrm{fv}})\mathrm{\Δt}=[\frac{P_{\mathrm{aa}}-P_{\mathrm{ivc}}}{R_s}-\frac{P_{\mathrm{ivc}}-P_{\mathrm{ra}}}{R_v}+\max (0,\frac{P_{\mathrm{fv}}-P_{\mathrm{ivc}}}{R_{\mathrm{iv}}})]\mathrm{\Δt}$

$\mathrm{\Δ}{P}_{\mathrm{ivc}}=\frac{\mathrm{\Δ}{V}_{\mathrm{ivc}}}{C_{\mathrm{ivc}}}$

$\mathrm{\Δ}{P}_{\mathrm{car}}=\frac{1}{C_{\mathrm{car}}}(i_c-i_h)\mathrm{\Δt}=\frac{\mathrm{\Δt}}{C_{\mathrm{car}}}[\frac{P_{\mathrm{ao}}-P_{\mathrm{car}}}{R_c}-\frac{P_{\mathrm{car}}-P_{\mathrm{jug}}}{R_h}]$

$\mathrm{\Δ}{P}_{\mathrm{jug}}=\frac{1}{C_{\mathrm{jug}}}(i_h-i_j)\mathrm{\Δt}=\frac{\mathrm{\Δt}}{C_{\mathrm{jug}}}[\frac{P_{\mathrm{car}}-P_{\mathrm{jug}}}{R_h}-\max (0,\frac{P_{\mathrm{jug}}-P_{\mathrm{ra}}}{R_j})]$

$\mathrm{\Δ}{P}_{\mathrm{fa}}=\frac{1}{C_{\mathrm{fa}}}(i_{\mathrm{ia}}-i_l)\mathrm{\Δt}=\frac{\mathrm{\Δt}}{C_{\mathrm{fa}}}[\frac{P_{\mathrm{aa}}-P_{\mathrm{fa}}}{R_{\mathrm{ia}}}-\frac{P_{\mathrm{fa}}-P_{\mathrm{fv}}}{R_l}]$

$\mathrm{\Δ}{P}_{\mathrm{fv}}=\frac{1}{C_{\mathrm{fv}}}(i_l-i_{\mathrm{fv}})\mathrm{\Δt}=\frac{\mathrm{\Δt}}{C_{\mathrm{fv}}}[\frac{P_{\mathrm{fa}}-P_{\mathrm{fv}}}{R_l}-\max (0,\frac{P_{\mathrm{fv}}-P_{\mathrm{ivc}}}{R_{\mathrm{iv}}})]$

$\mathrm{\Δ}{P}_{\mathrm{ppa}}=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δt}}{C_{\mathrm{ppa}}}(i_3-i_4)=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δt}}{C_{\mathrm{ppa}}}[\frac{P_{\mathrm{pa}}-P_{\mathrm{ppa}}}{R_{\mathrm{cppa}}}-\frac{P_{\mathrm{ppa}}-P_{\mathrm{ppv}}}{R_{\mathrm{pc}}}]$

$\mathrm{\Δ}{P}_{\mathrm{ppv}}=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δt}}{C_{\mathrm{ppv}}}(i_4-i_5)=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δt}}{C_{\mathrm{ppv}}}[\frac{P_{\mathrm{ppa}}-P_{\mathrm{ppv}}}{R_{\mathrm{pc}}}-\frac{P_{\mathrm{ppv}}-P_{\mathrm{la}}}{R_{\mathrm{cppv}}}]$

$\mathrm{\Δ}{V}_{\mathrm{ao}}=(i_o-i_c-i_a-i_{\mathrm{ht}})\mathrm{\Δt}=[\max (0,\frac{P_{\mathrm{lv}}-P_{\mathrm{ao}}}{R_{\mathrm{av}}})-\frac{P_{\mathrm{ao}}-P_{\mathrm{car}}}{R_c}-\frac{P_{\mathrm{ao}}-P_{\mathrm{aa}}}{R_a}-\frac{P_{\mathrm{ao}}-P_{\mathrm{ra}}}{R_{\mathrm{ht}}}]\mathrm{\Δt}$

$\mathrm{\Δ}{P}_{\mathrm{ao}}=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δ}{V}_{\mathrm{ao}}}{C_{\mathrm{ao}}}+f_{\mathrm{tp}}\frac{E}{d_0}\mathrm{\Δx}$

$\mathrm{\Δ}{V}_{\mathrm{pa}}=(i_2-i_3)\mathrm{\Δt}=[\max (0,\frac{P_{\mathrm{rv}}-P_{\mathrm{pa}}}{R_{\mathrm{pv}}})-\frac{P_{\mathrm{pa}}-P_{\mathrm{ppa}}}{R_{\mathrm{cppa}}}]\mathrm{\Δt}$

$\mathrm{\Δ}{P}_{\mathrm{pa}}=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δ}{V}_{\mathrm{pa}}}{C_{\mathrm{pa}}}+f_{\mathrm{tp}}\frac{E}{d_0}\mathrm{\Δx}$

$\mathrm{\Δ}{V}_{\mathrm{ra}}=(i_j+i_v+i_{\mathrm{ht}}-i_i)\mathrm{\Δt}=[\max (0,\frac{P_{\mathrm{jug}}-P_{\mathrm{ra}}}{R_j})+\frac{P_{\mathrm{ivc}}-P_{\mathrm{ra}}}{R_v}+\frac{P_{\mathrm{ao}}-P_{\mathrm{ra}}}{R_{\mathrm{ht}}}-\max (0,\frac{P_{\mathrm{ra}}-P_{\mathrm{rv}}}{R_{\mathrm{tv}}})]\mathrm{\Δt}$

$\mathrm{\Δ}{P}_{\mathrm{ra}}=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δ}{V}_{\mathrm{ra}}}{C_{\mathrm{ra}}}+f_{\mathrm{tp}}\frac{E}{d_0}(\mathrm{\Δx}+\frac{\mathrm{\Δ}{V}_{\mathrm{ra}}}{A_{\mathrm{ra}}})$

$\mathrm{\Δ}{V}_{\mathrm{rv}}=(i_i-i_2)\mathrm{\Δt}=[\max (0,\frac{P_{\mathrm{ra}}-P_{\mathrm{rv}}}{R_{\mathrm{tv}}})-\max (0,\frac{P_{\mathrm{rv}}-P_{\mathrm{pa}}}{R_{\mathrm{pv}}})]\mathrm{\Δt}$

$\mathrm{\Δ}{P}_{\mathrm{rv}}=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δ}{V}_{\mathrm{rv}}}{C_{\mathrm{rv}}}+\frac{E}{d_0}(\mathrm{\Δx}+\frac{\mathrm{\Δ}{V}_{\mathrm{rv}}}{A_{\mathrm{rv}}})$

$\mathrm{\Δ}{V}_{\mathrm{la}}=[\frac{P_{\mathrm{ppv}}-P_{\mathrm{la}}}{R_{\mathrm{cppv}}}-\max (0,\frac{P_{\mathrm{la}}-P_{\mathrm{lv}}}{R_{\mathrm{mv}}})]\mathrm{\Δt}$

$\mathrm{\Δ}{P}_{\mathrm{la}}=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δ}{V}_{\mathrm{la}}}{C_{\mathrm{la}}}+f_{\mathrm{tp}}\frac{E}{d_0}(\mathrm{\Δx}+\frac{\mathrm{\Δ}{V}_{\mathrm{la}}}{A_{\mathrm{la}}})$

$\mathrm{\Δ}{V}_{\mathrm{lv}}=(i_6-i_o)\mathrm{\Δt}=[\max (0,\frac{P_{\mathrm{la}}-P_{\mathrm{lv}}}{R_{\mathrm{mv}}})-\max (0,\frac{P_{\mathrm{lv}}-P_{\mathrm{ao}}}{R_{\mathrm{av}}})]\mathrm{\Δt}$

$\mathrm{\Δ}{P}_{\mathrm{lv}}=\mathrm{\Δ}{P}_{\mathrm{lung}}+\frac{\mathrm{\Δ}{V}_{\mathrm{lv}}}{C_{\mathrm{lv}}}+\frac{E}{d_0}(\mathrm{\Δx}+\frac{\mathrm{\Δ}{V}_{\mathrm{lv}}}{A_{\mathrm{lv}}})$

P(t+Δt)＝P(t)+ΔP(t)

Wherein: Δ t is the sample unit time, Δ V _aaCapacity of blood vessel increment for the abdomen artery within the Δ t time, Δ V _ivcCapacity of blood vessel increment for inferior caval vein within the Δ t time, Δ V _aoCapacity of blood vessel increment for aorta pectoralis within the Δ t time, Δ V _paCentered by the capacity of blood vessel increment of pulmonary artery within the Δ t time, Δ V _raBe the volume increment of atrium dextrum within the Δ t time, Δ V _rvBe the volume increment of right ventricle within the Δ t time, Δ V _laBe the volume increment of atrium sinistrum within the Δ t time, Δ V _lvBe the volume increment of left ventricle within the Δ t time, Δ P _aaBe abdomen arterial pressure increment in the Δ t time, Δ P _ivcBe inferior caval vein blood pressure increment in the Δ t time, Δ P _carBe Δ t time arteria carotis interna blood pressure increment, Δ P _jugBe jugular vein blood pressure increment in the Δ t time, Δ P _faBe FBP increment in the Δ t time, Δ P _fvBe femoral vein blood pressure increment in the Δ t time, Δ P _ppaFor periphery pulmonary artery blood in the Δ t time is pressed increment, Δ P _LungBe intrapulmonic pressure increment in the Δ t time, Δ P _ppvFor periphery pulmonary vein in the Δ t time is pressed increment, Δ P _aoBe aorta pectoralis blood pressure increment in the Δ t time, Δ P _paBe center pulmonary artery blood pressure increment in the Δ t time, Δ P _raBe blood pressure increment in atrium dextrum in the Δ t time, Δ P _rvBe right ventricle blood pressure increment in the Δ t time, Δ P _laBe blood pressure increment in atrium sinistrum in the Δ t time, Δ P _lvBe left ventricle blood pressure increment in the Δ t time, P (t+ Δ t) is t+ Δ t force value constantly, and P (t) is t force value constantly, Δ P (t) is carved into (t+ Δ t) pressure increment constantly for from t the time, Δ x is the chest compression depth in the Δ t time, i.e. breastbone displacement increment, f _tpBe the chest pump factor, E is Young's modulus of elasticity, d ₀Be chest depth, A _raBe atrium dextrum cross-sectional area, A _rvBe right ventricle cross-sectional area, A _laBe atrium sinistrum cross-sectional area, A _lvBe the left ventricle cross-sectional area, max () function is maximal value value function;

C _aaBe abdominal aorta compliance, C _ivcBe inferior caval vein compliance, C _carBe carotid artery compliance, C _jugBe jugular vein compliance, C _faBe femoral artery compliance, C _fvBe femoral vein compliance, C _ppaBe periphery pulmonary artery compliance, C _ppvBe periphery pulmonary vein compliance, C _aoBe aorta pectoralis compliance, C _paCentered by the pulmonary artery compliance, C _raBe atrium dextrum compliance, C _rvBe right ventricle compliance, C _laBe atrium sinistrum compliance, C _lvBe the left ventricle compliance.

R _aBe the resistance of aorta pectoralis blood, R _sBe the resistance of abdominal vascular net blood, R _iaBe the resistance of bone arterial blood, R _vBe Inferior Vena Cava Blood resistance, R _ivBe the resistance of bone venous blood, R _cBe the resistance of arteria carotis blood, R _hBe the resistance of brain blood, R _jBe the resistance of jugular vein blood, R _lBe the resistance of shank rete vasculosum blood, R _CppaBe the resistance of periphery pulmonary artery blood, R _pcBe the resistance of PC net blood, R _CppvBe the resistance of periphery pulmonary vein, R _avBe the resistance of aorta petal blood, R _htBe cardiac blood resistance, R _pvBe the resistance of lung valve blood, R _tvBe the resistance of tricuspid valve blood, R _mvBe the resistance of bicuspid valve blood.

i _aBe aortic flow, i _sBe belly blood flow, i _iaBe bone artery blood flow, i _vBe superior vena cava blood flow, i _fvBe femoral vein blood flow, i _cBe carotid artery flow, i _hBe brain blood flow, i _jBe jugular vein blood flow, i ₁Be shank blood vessel network blood flow, i ₂Be lung valve blood flow, i ₃Be periphery PBF, i ₄Be pulmonary capillary blood flow, i ₅Be periphery Pulmonary Venous Flow, i ₆Be aortic blood flow, i _oBe heart output blood flow, i _htBe cardiac flow, i _iBe heart input blood flow,

P _aoBe aorta pectoralis blood pressure, P _aaBe abdomen arterial pressure, P _ivcBe inferior caval vein blood pressure, P _faBe FBP, P _raBe atrium dextrum blood pressure, P _fvBe femoral vein blood pressure, P _carBe Blood pressure of carotid artery, P _jugBe jugular vein blood pressure, P _paCentered by the pulmonary artery blood pressure, P _ppaBe periphery pulmonary artery blood pressure, P _ppvBe periphery pulmonary vein blood pressure, P _laBe atrium sinistrum blood pressure, P _rvThe right ventricle blood pressure, P _paCentered by the pulmonary artery blood pressure, P _lvBe the left ventricle blood pressure.

3. chest compression physiological feedback signal simulator according to claim 1, is characterized in that, described Coronary Perfusion Pressure emulation module calls algorithmic formula:

$\mathrm{CPP}=\frac{2\underset{t=T/2}{\overset{T}{\mathrm{\Σ}}}\left(\right|P_{\mathrm{ao}}\left(t\right)-P_{\mathrm{ra}}\left(t\right)\left|\mathrm{\Δt}\right)}{T}$

Wherein: CPP is Coronary Perfusion Pressure, and T is an external chest compression cycle, and Δ t is the sample unit time, P _ao(t) and P _ra(t) be respectively t aorta pectoralis blood pressure and atrium dextrum blood pressure constantly.

4. chest compression physiological feedback signal simulator according to claim 1, is characterized in that, described average auterial diastole presses emulation module to call algorithmic formula:

$\mathrm{MARP}=\frac{2\underset{t=T/2}{\overset{T}{\mathrm{\Σ}}}\left(P_{\mathrm{ao}}\left(t\right)\mathrm{\Δt}\right)}{T}$

Wherein: MARP is that average auterial diastole is pressed, and T is an external chest compression cycle, and Δ t is the sample unit time, P _ao(t) be t aorta pectoralis blood pressure constantly.

5. chest compression physiological feedback signal simulator according to claim 1, is characterized in that, described Coronary Perfusion Pressure-End-tidal carbon dioxide dividing potential drop concerns that emulation module calls algorithmic formula:

PETCO2＝0.465×CPP+3.279

PETCO2 is the End-tidal carbon dioxide dividing potential drop, and CPP is Coronary Perfusion Pressure.

6. the described chest compression physiological feedback signal simulator of any one according to claim 1～5, is characterized in that, the initial pressure value unification of described 14 vasculars and organ is set to 10mmHg.

7. chest compression physiological feedback signal simulator according to claim 1, it is characterized in that, also comprise external interface, described external interface is exported the following data from described microcontroller: Coronary Perfusion Pressure emulated data, average auterial diastole are pressed emulated data and End-tidal carbon dioxide dividing potential drop emulated data.

8. chest compression physiological feedback signal simulator according to claim 1, it is characterized in that, also comprise loudspeaker, described loudspeaker is driven by described microcontroller, when the Coronary Perfusion Pressure emulated data, when average auterial diastole presses emulated data and End-tidal carbon dioxide dividing potential drop emulated data to exceed default safe range data, described microcontroller drives described loudspeaker and sends alerting signal.

9. chest compression physiological feedback signal simulator according to claim 1, it is characterized in that, also comprise peripheral memory, described peripheral memory is stored the following data from described microcontroller: the chest pump factor, chest compression depth data, external chest compression frequency data, Coronary Perfusion Pressure emulated data, average auterial diastole are pressed emulated data, End-tidal carbon dioxide dividing potential drop emulated data.

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