Device and method for the dynamically sealing occlusion or space-filling tamponade of a hollow organ

Abstract

A device (1) for the tracheal intubation of and the administration of ventilation to a patient for rapid volume-compensating sealing of the trachea, wherein the sealing surfaces of a preferably fully and residually formed balloon-like film body (4) abut the wall of the trachea with a sealing pressure of the balloon (4) which is as constant as possible and follow the thoracic pressure acting on the balloon with the least possible time latency with regard to corresponding fluctuations of the balloon inflation pressure, and the trachea is kept sealed under such dynamic fluctuations or respiration synchronously alternating fluctuations of the balloon inflation pressure. This is enabled by a defined large lumen (7, 5) supply of the balloon inflation medium, the supplying lumen being measured in such a way that a sealing pressure-maintaining extracorporeal volume compensation that works in a time synchronous manner can be achieved in the sealing balloon element.

Claims

1. A device for the dynamically sealing intubation of a hollow organ, comprising a tube in the form of a shaft that can be inserted into the hollow organ, with a primary lumen to provide access through or to the hollow organ in question, and comprising an intracorporeal sealing balloon, which surrounds a distal region of the shaft of said tube in the manner of a cuff for the purpose of sealing it against the hollow organ, wherein one or more secondary lumens for filling said intracorporeal sealing balloon are integrated into the wall of at least a proximal region of said shaft, wherein, within each cross-sectional plane that is intersected perpendicularly by the local longitudinal direction of the device, the following applies for the overall interior cross-section Q1 of the primary lumen and the sum Q2 of the interior cross-sections of all secondary lumens:
Q2/(Q1+Q2)±0.06, wherein a connection for an extracorporeal filling tube, which connection communicates with all secondary lumens, is provided at a proximal end of the tube, and wherein, in said extracorporeal filling tube, a) a one-way valve is disposed which permits a flow in case of a pressure gradient from an extracorporeal reservoir balloon, which is or can be connected to the extracorporeal filling tube, in a direction toward the intracorporeal sealing balloon, but not in the opposite direction, and b) a flow constriction is arranged which permits only a limited flow in every flow direction, wherein the one-way valve and the flow constriction are arranged in parallel.

2. The device according to claim 1, characterized in that the proximal region of said shaft comprises a tubular shaft element, wherein the intracorporeal sealing balloon or a proximal region of the intracorporeal sealing balloon ends at an end face of said tubular shaft element consisting of a tube material, in which the primary lumen continues as an interior opening radially within said tubular shaft element, while the one or more secondary lumens continue in the form of one or more channels molded into the tube material of said tubular shaft element.

3. The device according to claim 2, characterized in that the minimal overall cross-section of all channels molded into the tube material of said tubular shaft element as the one or more secondary lumens is greater than or equal to the maximum cross-section of an annular secondary lumen in the proximal region of the balloon.

4. The device according to claim 1, characterized in that an annular structure acting as a collecting channel, with which all secondary lumens communicate, is located in a region of the proximal end of the tube.

5. The device according to claim 4, characterized in that the connector for the extracorporeal filling tube, which communicates with all secondary lumens, is provided on the annular structure acting as the collecting channel.

6. The device according to claim 1, characterized in that the pressure in the extracorporeal reservoir balloon is actively controlled or regulated.

7. The device according to claim 6, characterized in that the pressure in the extracorporeal reservoir balloon is actively regulated such that the pressure in the intracorporeal sealing balloon is kept constant.

8. The device according to claim 7, characterized in that the pressure in the intracorporeal sealing balloon is measured and serves as an actual value for a control loop, which exerts an influence on the pressure in the extracorporeal reservoir balloon.

9. The device according to claim 1, characterized in that, within each cross-sectional plane that is intersected perpendicularly by the local longitudinal direction of the device, the following applies for the overall interior cross-section Q1 of the primary lumen and the sum Q2 of the interior cross-sections of all secondary lumens:
Q2/(Q1+Q2)≥0.08, or
Q2/(Q1+Q2)≥0.10, or
Q2/(Q1+Q2)≥0.12.

10. The device according to claim 1, characterized in that the intracorporeal sealing balloon has a radially widened distal region for making a seal and a proximal region, which adjoins the distal region and tapers radially relative to it, as an envelope for the secondary lumen(s) for filling the distal sealing region.

11. The device according to claim 1, characterized in that the intracorporeal sealing balloon is performed with different outer diameters in its distal and proximal regions.

12. The device according to claim 1, characterized in that, in a proximal region of the intracorporeal sealing balloon, only one secondary lumen is provided which concentrically externally surrounds the primary lumen.

13. The device according to claim 1, characterized in that a proximal region of the intracorporeal sealing balloon does not extend all the way to the proximal end of the tube but ends before that.

14. The device according to claim 1, characterized in that the extracorporeal reservoir balloon has a larger volume in its freely deployed state than the intracorporeal sealing balloon in the distal region of the shaft of the tube.

15. The device according to claim 1, characterized in that the extracorporeal reservoir balloon is charged with a constant or near-constant pressure, for instance by a weight or a spring element.

16. A method for the dynamically sealing intubation of a hollow organ, the method comprising inserting a device into the hollow organ, the device comprising a tube in the form of a shaft that can be inserted into the hollow organ, with a primary lumen to provide access through or to the hollow organ in question, and comprising an intracorporeal sealing balloon, which surrounds a distal region of the shaft of said tube in the manner of a cuff for the purpose of sealing it against the hollow organ, wherein one or more secondary lumens for filling said intracorporeal sealing balloon are integrated into the wall of at least a proximal region of said shaft, wherein, the pressure within the intracorporeal sealing balloon is kept nearly constant in such a way that when the volume of the hollow organ changes, a corresponding amount of the filling medium flows through one or more secondary lumens, wherein, within each cross-sectional plane that is intersected perpendicularly by the local longitudinal direction of the device, the following applies for the overall interior cross-section Q1 of the primary lumen and the sum Q2 of the interior cross-sections of all secondary lumens:
Q2/(Q1+Q2)≥0.06, wherein a connection for an extracorporeal filling tube, which connection communicates with all secondary lumens, is provided at a proximal end of the tube, and wherein, in said extracorporeal filling tube, a) a one-way valve is disposed which permits a flow in case of a pressure gradient from an extracorporeal reservoir balloon, which is or can be connected to the extracorporeal filling tube, in a direction toward the intracorporeal sealing balloon, but not in the opposite direction, and b) a flow constriction is arranged which permits only a limited flow in every flow direction, wherein the one-way valve and the flow constriction are arranged in parallel.

17. The method according to claim 16, characterized in that the one or more secondary lumens to the intracorporeal sealing balloon are dimensioned such that, at a pressure level within a balloon system comprising the intracorporeal sealing balloon and the extracorporeal reservoir balloon of 20 to 35 mbar above atmospheric pressure, initial pressure differences within the balloon system have reduced to a residual pressure difference of 5 mbar or less, or to a residual pressure difference of 2 mbar or less, or to a residual pressure difference of 1 mbar or less after a compensation time of max. 20 ms, or after a compensation time of max. 10 ms.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further features, details, advantages and effects based on the invention arise from the following description of preferred embodiments of the invention and with the aid of the accompanying drawings.

(2) FIG. 1 shows a claimed tracheal tube in combination with an external volume-regulating device.

(3) FIG. 2 shows the volume-shafting gap S relative to the overall diameter G in the vicinity of the proximal balloon extension.

(4) FIG. 3 shows a tracheal tube with multiple volume-shifting supply lines arranged in or on the catheter shaft.

(5) FIG. 3a shows a cross-section of the supplying, shaft-integrated lumens of the tube described in FIG. 3.

(6) FIG. 4 shows a particular embodiment of the tube shown in FIG. 1, in which the trachea-sealing balloon extends beyond the glottis plane.

(7) FIG. 5 shows an illustrative embodiment of a claimed tracheostomy cannula.

(8) FIG. 6 shows a claimed tracheal tube with a sensor element in the region of the trachea-sealing balloon segment and a regulator unit that is arranged with a sensor in a control loop.

(9) FIG. 7 shows a combined valve/throttle mechanism which prevents the balloon from quickly emptying into the regulator/reservoir, which would be critical for the seal.

(10) FIG. 8 shows a gastric tube with a proximally extended balloon segment for the dynamically sealing tamponade of the esophagus in combination with an extracorporeal isobaric volume reservoir.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(11) FIG. 1 describes, in an illustrative total overview, the communicating connection/coupling of a claimed device 1, in the form of a tracheal tube, with a preferably gravity- or spring-driven, isobaric volume reservoir 2.

(12) The supply chamber formed by the freely communicating coupling of the tracheal tube and volume reservoir 2 consists of the trachea-sealing balloon segment 4, the tube-like tapered balloon end 5 that connects in the proximal direction, the supply lumen(s) in the proximal shaft element 6, the flexible supply line 7 to the reservoir that attaches to the shaft as well as the reservoir volume 8 of the regulator.

(13) The distal shaft segment of the tube 3 supports a trachea-sealing balloon 4 at its distal end, said balloon being sealingly attached at its distal end 9a to the surface of the shaft. A tube-like proximal balloon segment 5, which tapers relative to the diameter of the sealing balloon segment 4, attaches to the balloon segment 4 in the proximal direction. Its proximal end locks tightly to the surface of the distal end 9b of the proximal shaft element 6.

(14) If a decrease in intrathoracic pressure occurs during the course of inhaling (inspiration), and thus a corresponding transient widening of the tracheal cross-section, which in turn causes a corresponding drop in pressure within the balloon body placed in the trachea, volume flows from the reservoir 2 to the sealing balloon segment 4, wherein the reservoir continuously charges the volume with a defined pressure. As a result, the tracheal sealing pressure can be maintained even when the patient inhales deeply, with a possible pressure drop in the thorax and/or in the trachea-sealing balloon to sub-atmospheric levels, without relevant losses in the sealing capacity.

(15) In a preferred embodiment, the reservoir 2 consists of a reservoir body 8, which can be configured e.g. as a balloon or bellows, and establishes a constant isobaric pressure in the supply chamber by a force K acting on the reservoir.

(16) Crucial to achieving the smallest possible time latency between the initial widening of the tracheal cross-section or the initial reduction of the transmural thoracic forces acting on the tracheal sealing balloon and the start of a seal-creating shift of filling medium to the trachea-sealing balloon segment is, above all, the flow-affecting cross-sectional area of the gap S available the between the distal shaft segment 9 and the proximal extension 5 of the balloon.

(17) In the following figure, the invention proposes especially advantageously dimensioned ratios of the cross-sectional area S to the cross-sectional area of the ventilation lumen ID and to the overall cross-sectional area OD of the catheter between the proximal shaft 6 and the trachea-sealing balloon segment 4.

(18) FIG. 2 shows a cross-section through the volume-supplying segment 5 of the balloon of the tracheal tube pictured in FIG. 1, said segment attaching to the trachea-sealing balloon in the proximal direction.

(19) S designates the gap surface that is preferred for the supply of filling medium to the balloon. It is defined as the difference between the cross-sectional area G, which is delimited by the sleeve wall of the supplying balloon end 5, and the cross-sectional area OD of the shaft body, which is delimited by the outer surface of the shaft. Here the cross-sectional area S should be 1/10 to 5/10 of cross-sectional area G, especially preferably 2/10 to 3/10 of cross-sectional area G.

(20) Relative to the cross-sectional area ID of the inner lumen of the shaft body, cross-sectional area S should amount to 2/10 to 6/10 of cross-sectional area ID, especially preferably 3/10 to 4/10 of cross-sectional area ID.

(21) In addition to air as the preferred medium, liquid media can also be used to fill the trachea-sealing system.

(22) For the quantitative calculation of the flow conditions in the volume-conducting interior space of the balloon, in particular based on the pressure ratios in the trachea-sealing balloon segment 4, the following place-holder values should be used:

(23) V.sub.i Volume of the distal balloon segment 4

(24) p.sub.i Pressure in the distal balloon segment 4

(25) ρ.sub.i Filling density in the distal balloon segment 4

(26) M.sub.1 Air mass in the distal balloon segment 4

(27) V.sub.2 Volume of the extracorporeal reservoir 8

(28) P.sub.2 Pressure in the extracorporeal reservoir 8

(29) ρ.sub.2 Filling density in the extracorporeal reservoir 8

(30) m.sub.2 Air mass in the extracorporeal reservoir 8

(31) The following applies for air masses m.sub.1, m.sub.2:

(32) $\begin{array}{cc}{m}_1\left(t\right)=m_{1,0}+{\int }_{T=0}^{T=t}{S}_{m,1}\left(T\right)d_T& \left(1\right)\\ m_2\left(t\right)=m_{2,0}-{\int }_{T=0}^{T=t}{S}_{m,2}\left(T\right)d_T& \left(2\right)\end{array}$

(33) S.sub.m,v stands for the air flow to the respective balloon 4, 8 as an air mass flow.

(34) According to the Hagen-Poiseuille equation, the following is true for the mass fluid flow through a line with a circular cross-section and with an inner radius R and length I:

(35) $\begin{array}{cc}{S}_{m,1}=\frac{{\rho }_1.Math.\pi \left(p_2-p_1\right).Math.R^4}{8\eta .Math.I}& \left(3a\right)\\ S_{m,2}=\frac{{\rho }_2.Math.\pi \left(p_1-p_2\right).Math.R^4}{8\eta .Math.I}& \left(3b\right)\end{array}$

(36) If, however—as in this case—the secondary lumen represents an annular structure around a primary lumen, then the Hagen-Poiseuille formula does not exactly apply.

(37) Instead, one must consider a space with a strip-like cross-section, which can ideally be imagined in a straightened form, i.e. having a flat structure or a rectangular cross-section with length L and thickness D, i.e. with a cross-sectional area Q=L.Math.D.

(38) Between two plates at a distance D, the following applies for the distribution of the flow rate v(x) along a direction x perpendicular to the plates:

(39) $\begin{array}{cc}v\left(x\right)=\frac{\left(p_1-p_2\right).Math.\left(D^2/4-x^2\right)}{2\eta .Math.I}& \left(4\right)\end{array}$

(40) This is a parabolic curve. By integration over cross-sectional area Q, the mass flowing through cross-sectional area Q during time t can be determined:

(41) $\begin{array}{cc}{S}_{m,1}=\frac{{\rho }_1.Math.\left(p_2-p_1\right).Math.L.Math.D^3}{12\eta .Math.I}& \left(5a\right)\\ S_{m,2}=\frac{{\rho }_2.Math.\left(p_1-p_2\right).Math.L.Math.D^3}{12\eta .Math.I}& \left(5b\right)\end{array}$

(42) In any case, these formulas replace the above Hagen-Poiseuille formulas (3a) and (3b) for annular balloon segment 5.

(43) Here η stands for the dynamic viscosity of the flowing gas. For air:

(44) η is 17.1 μPa.Math.s at 273 K.

(45) Furthermore, because of the thermal equation of state of ideal gases, the following applies in the balloon 4:
η.sub.1=ρ.sub.1.Math.R.sub.S.Math.T.sub.1  (6a)
and in balloon 8:
η.sub.2=ρ.sub.2.Math.R.sub.S.Math.T.sub.2.  (6b)

(46) In this case, R.sub.S is the individual or specific gas constant, which for air has the value 287.058 J/(kg*K).

(47) T.sub.v is the temperature in balloon sections 4 and 5 and in the balloon 8.

(48) For a temperature of 23° C. or 296 K, the factor
k=R.sub.S,air.Math.T.sub.23° C.=85.Math.10.sup.3J(kg.Math.K)  (7)

(49) It should be assumed hereafter that the temperature both in balloon 4 and in balloon 8 is a constant 23° C.:
T.sub.1=T.sub.2=296 K.

(50) Then the following applies:
p.sub.1=ρ.sub.1.Math.k  (8)
p.sub.2=ρ.sub.2.Math.k  (9)

(51) Thus by inserting equation (5a) into equation (1), the result is:

(52) $\begin{array}{cc}{m}_1\left(t\right)=m_{1,0}+{\int }_{T=0}^{T=t}\frac{{\rho }_1.Math.L.Math.D^3}{12\eta .Math.I}\left(p_2-p_1\right)d_T& \left(10\right)\end{array}$

(53) With equation (8), it follows that:

(54) $\begin{array}{cc}{m}_1\left(t\right)=m_{1,0}+{\int }_{T=0}^{T=t}\frac{{\rho }_1.Math.L.Math.D^3}{12\eta .Math.I.Math.k}{p}_1\left(p_2-p_1\right)d_T& \left(11\right)\end{array}$

(55) Moreover, the following applies in balloon 4:

(56) $\begin{array}{cc}\frac{m_1}{V_1}={\rho }_1=\frac{p_1}{k}& \left(12\right)\end{array}$

(57) Therefore, the following can be written in equation (11) for mass m.sup.1:

(58) $\begin{array}{cc}{m}_1=\frac{V_1.Math.p_1}{k}& \left(13\right)\end{array}$

(59) The result:

(60) $\begin{array}{cc}\frac{V_1}{k}.Math.p_1\left(t\right)=\frac{V_1}{k}.Math.p_{1.0}-{\int }_{T=0}^{T=t}\frac{L.Math.D^3}{12\eta .Math.l.Math.k}.Math.\left[p_1^2-p_1{p}_2\right]d_T& \left(14\right)\end{array}$

(61) The entire equation can be shorted to V.sub.1/k. A differentiation on both sides results in:

(62) 0$\begin{array}{cc}\frac{{\mathrm{dp}}_1}{\mathrm{dt}}=-\frac{L.Math.D^3}{12V_1\eta l}.Math.\left[p_1^2-p_1{p}_2\right]& \left(15\right)\end{array}$

(63) This is a Bernoulli differential equation in the form:

(64) $\begin{array}{cc}{x}^{\prime }=-a.Math.x.Math.\left(x-b\right),& \left(16\right)\\ \mathrm{wherein}& \\ a=\frac{L.Math.D^3}{12V_1\eta l}& \left(17\right)\\ b=p_2& \left(18\right)\end{array}$

(65) Hereafter it should be assumed that balloon 8 is significantly larger than balloon 4:
V.sub.2>>V.sub.1.

(66) From this it follows that the pressure p.sub.2 in balloon 8 remains nearly constant, even when pressure p.sub.1 in balloon 4 briefly changes. Under this assumption, the coefficients a and b from Bernoulli differential equation (16) are constant, and the solution to the Bernoulli differential equation is:

(67) $\begin{array}{cc}x\left(t\right)=\frac{b}{1-e^{-\mathrm{abt}-{\mathrm{bc}}_1}}& \left(19\right)\end{array}$

(68) The constant of integration c.sub.1 can be determined as follows:

(69) $\begin{array}{cc}{p}_1\left(t\right)=\frac{p_2}{1-e^{-{\mathrm{ap}}_{2}t-p_2{c}_1}}& \left(20\right)\end{array}$

(70) For t=0, the following must apply:
P.sub.1(t)=p.sub.1.0  (21)

(71) The result:

(72) $\begin{array}{cc}{p}_{1.0}=\frac{p_2}{1-e^{-p_2{c}_1}}& \left(22\right)\\ \frac{p_2}{p_{1.0}}=1-e^{-p_2{c}_1}& \left(23\right)\\ e^{-p_2{c}_1}=\frac{p_{1.0}-p_2}{p_{1.0}}& \left(24\right)\\ -p_2{c}_1=\ln \frac{p_{1.0}-p_2}{p_{1.0}}& \left(25\right)\\ c_1=-\frac{1}{p_2}.Math.\ln \frac{p_{1.0}-p_2}{p_{1.0}}=\frac{1}{p_2}.Math.\ln \frac{p_{1.0}}{p_{1.0}-p_2}& \left(26\right)\end{array}$

(73) Inserted into equation (2), this provides:

(74) $\begin{array}{cc}\frac{p_1\left(t\right)}{p_{1.0}}=\frac{p_2}{p_{1.0}-\left[p_{1.0}-p_2\right].Math.e^{-\left(\pi R^4{p}_{2}t\right)/\left(8V_1\eta l\right)}}& \left(27\right)\end{array}$

(75) This equation is in the form:

(76) $\begin{array}{cc}\frac{p_1\left(t\right)}{p_{1.0}}=\frac{p_2}{p_{1.0}-\left[p_{1.0}-p_2\right].Math.e^{-t/T}}& \left(28\right)\\ \mathrm{where}& \\ \tau =\left(12.Math.V_1.Math.\eta .Math.1\right)/\left(L.Math.D^3.Math.p_2\right)& \left(29\right)\end{array}$

(77) The following applies for minor pressure fluctuations in balloon 4, for example:
P.sub.1.0≈0.9p.sub.2

(78) Moreover, for t=T:
e.sup.−t/τ=e.sup.−1≈0.368=k.sub.1.

(79) Additionally, for t=2τ:
e.sup.−t/τ=e.sup.−2≈0.135=k.sub.2.

(80) And for t=4τ:
e.sup.−t/τ=e.sup.−4≈0.018=k.sub.4.

(81) In equation (28) this yields:

(82) $\frac{p_1\left(t=\mathrm{vT}\right)}{0.9p_2}=\frac{p_2}{0.9p_2-\left(0.9p_2-p_2\right).Math.k_v}$$\mathrm{and}\text{:}$$\frac{p_1\left(t=\mathrm{vT}\right)}{0.9p_2}=\frac{p_2}{\left(0.9+0.1.Math.k_v\right).Math.p_2}$

(83) The result:

(84) $p_1\left(t=T\right)=p_2.Math.\frac{0.9}{0.9+0.1.Math.0.368}\approx 0.96.Math.p_2$

(85) The control deviation of approximately 0.04.Math.p.sub.2 remaining after t=τ corresponds to 40% of the initial deviation of 0.10.Math.p.sub.2.

(86) $p_1\left(t=2T\right)=p_2.Math.\frac{0.9}{0.9+0.1.Math.0.135}\approx 0.98.Math.p_2$

(87) The control deviation of approximately 0.02.Math.p.sub.2 remaining after t=2τ corresponds to 20% of the initial deviation of 0.10.Math.p.sub.2.

(88) 0$p_1\left(t=4T\right)=p_2.Math.\frac{0.9}{0.9+0.1.Math.0.018}\approx 0.99.Math.p_2$

(89) The control deviation of approximately 0.01.Math.p.sub.2 remaining after t=4τ corresponds to 10% of the initial deviation of 0.10.Math.p.sub.2.

(90) When applied within the framework of thoracic respiration, it should be noted that a breathing cycle lasts about 3 sec. So that the cuff does not become leaky over the course of a thoracic breathing cycle, this compensation time should be t.sub.a=VT=20 ms, wherein, with the parameter v, it is possible to choose how good the compensation should be after 20 ms.

(91) This results in T=20 ms/v.

(92) The minimal result to be sought for v=1 and t.sub.a=20 is provided as follows:

(93) From this comes:

(94) $T=20.Math.{10}^{-3}s=\frac{12.Math.5.Math.{10}^{-6}{m}^3.Math.0.2m.Math.17.1.Math.{10}^{-6}\mathrm{Pas}}{L.Math.D^3.Math.{10}^5\mathrm{Pa}}$

(95) In the process, it was assumed: V.sub.1=5 cm.sup.3 I=20 cm p.sub.2=10.sup.5 Pa

(96) This results in:
L.Math.D.sup.3=10.26.Math.10.sup.−14m.sup.4.

(97) It should hereafter further be assumed that, at most, an interior opening with a maximum diameter of 10 mm, corresponding to a radius of 5 mm, is available in the tracheal tube. If one further disregards the cross-section of the outer surface of tube 3 and balloon 4, then the secondary lumen extends a maximum distance outward, and a medium radius R.sub.m of e.g. 4.8 mm can thus be assumed. From this, it is possible to calculate a circumferential length L.sub.m=2.Math.TT.Math.R.sub.m of approximately 30 mm=30.Math.10.sup.−3 m, and from this results:
D.sup.3=10.26*10.sup.−14m.sup.4/L
and:
D.sup.3=102.6.Math.10.sup.−12m.sup.3/30
D.sup.3=3.42.Math.10.sup.−12m.sup.3
D=1.5.Math.10.sup.−4m=0.15 mm.

(98) The secondary lumen thus has a cross-sectional area Q.sub.2 of
Q.sub.2=L.Math.D=30.Math.mm.Math.0.15 mm=4.5 mm.sup.2.

(99) For cross-sectional area Q.sub.1 of the primary lumen, D can be subtracted from the 5 mm maximum radius of the tracheal tube, and the result is 4.8 mm. This corresponds to a cross-sectional area Q.sub.1 of
Q.sub.1=4.85 mm.Math.4.85 mm.Math.3.14=74 mm.sup.2.

(100) The overall free cross-section Q=Q.sub.1+Q.sub.2=78.5 mm.sup.2. This means:
Q.sub.2/Q=Q.sub.2/(Q.sub.1+Q.sub.2)=4.5/78.5=0.06.

(101) If a shorter compensation time or better compensation within this compensation time t.sub.a is required, then more stringent requirements arise for the above ratio. Accordingly, the value of 0.06 represents the absolute lower limit, which should never be undercut because this would threaten aspiration. In order to have a safety reserve, at least the following should be selected:
Q.sub.2/Q=Q.sub.2/(Q.sub.1+Q.sub.2)≥0.08.

(102) Moreover, the extracorporeal supply line 7 was likewise disregarded in the above calculation, although its contribution to flow resistance is not insignificant. It is therefore recommended:
Q.sub.2/Q=Q.sub.2/(Q.sub.1+Q.sub.2)≥0.10.

(103) If, on the other hand, one sets v=4 and t.sub.a=10 ms (i.e. the requirement that the remaining control deviation should be less than 10% after 10 ms), then the following is obtained:

(104) $T=10\mathrm{ms}/4=25.Math.{10}^{-4}s=\frac{12.Math.5.Math.{10}^{-6}{m}^3.Math.0.2m.Math.17.1.Math.{10}^{-6}\mathrm{Pas}}{L.Math.D^3.Math.{10}^5\mathrm{Pa}}$

(105) This then results in:
L.Math.D.sup.3=82.08.Math.10.sup.−14m.sup.4,
D.sup.3=82.08.Math.10.sup.−14m.sup.4/L
or, when L=30 mm:
D.sup.3=27.4.Math.10.sup.−12m.sup.3
D=3.Math.10.sup.−4m=0.3 mm.

(106) The secondary lumen thus has a cross-sectional area Q.sub.2 of
Q.sub.2=L.Math.D=30.Math.mm.Math.0.3 mm=9 mm.sup.2.

(107) For the cross-sectional area Q.sub.1 of the primary lumen, D can be subtracted from the 5 mm maximum radius of the tracheal tube, and the result is then 4.6 mm. This corresponds to a cross-sectional area Q.sub.1 of
Q.sub.1=4.6 mm.Math.4.6 mm.Math.3.14=66 mm.sup.2.

(108) The overall free cross-section Q=Q.sub.1+Q.sub.2=75 mm.sup.2. This means:
Q.sub.2/Q=Q.sub.2/(Q.sub.1+Q.sub.2)=9/75=0.12.

(109) FIG. 3 describes an embodiment of the shaft body 3 that is integrated into the shaft wall, has one or more volume-supplying channels with a volume-shifting overall cross-section that corresponds in its flow mechanics with the ratios represented in FIG. 2. Here the shaft body preferably consists of multi-lumen extruded tube material which, in addition to a central lumen for ventilation, contains supply lumens disposed around said central lumen. In one such multi-lumen embodiment, the individual lumens can be bundled or combined at the proximal shaft end by an annular structure 10.

(110) FIG. 3a shows an illustrative shaft cross-section with multi-lumen volume supply lines 11.

(111) FIG. 4 shows an embodiment variant in which the trachea-sealing balloon segment 4 is extended proximally up to or beyond the plane of the vocal folds GL. This embodiment, in which the balloon segment that is elongated in this way protrudes proportionally from the thorax and is thus not exposed to fluctuations in thoracic pressure, permits an especially large balloon volume that is capable of developing a pressure-receiving buffer effect when a reduction in transmural force on the balloon, caused by breathing mechanics, occurs in the distal, tracheal segment of the balloon. The volume reserve created in this way also has a partial buffering effect when no external volume-compensating unit is connected to the tracheal tube.

(112) In addition, owing to the large contact surface with the exposed tracheal, glottic and supraglottic mucous membranes, a maximally elongated migration path for secretions and pathogens contained therein is created.

(113) To facilitate the trans-glottic positioning of the tube, the balloon can be provided with a circular constriction 12 in the region of the vocal cords GL. This constriction additionally allows for the free movement of the vocal folds, largely independent of the prevailing filling pressure in the balloon.

(114) The distal shaft segment is preferably configured as a thin-walled, single-lumen tube that is stabilized by a corrugation in the shaft wall. The distal shaft transitions in the proximal direction into a shaft segment 6 that, as described in FIG. 1, allows for a large-bore supply line to the proximal balloon segment 5. In a preferred embodiment, as described in FIG. 3a, the shaft 6 is designed with a multi-lumen profile. The multi-lumen shaft segment 6 is configured to be stable enough to serve as a bite guard, which prevents a lumen-sealing closure of the ventilation lumen.

(115) The supplying lumens that are integrated into the shaft 6 can be bundled by a terminal element 10 at the proximal end of the tube. In turn, the connection element 7 is attached to a reservoir with a sufficiently large-bore connection.

(116) The thin-walled, single-lumen shaft body 3 is equipped with a wavy corrugation to stabilize the shaft lumen and to permit the largely tension-free axial bending of the shaft. In the preferred embodiment, it should be possible in this way to bend the shaft from 90 to 135 degrees without relevant lumen constriction and without elastic restoring forces acting upon the tissue.

(117) For inner shaft diameters of 7 to 10 mm in the combination of a wall thickness of ca. 0.4 mm, a Shore hardness value of 95A, a peak-to-peak wave distance of 0.5 mm and a wave amplitude of 0.75 mm, it is possible to produce a correspondingly kink-resistant lumen- and flow-optimized shaft.

(118) In the case of the corrugated embodiment of the shaft 3, when an exchangeable inner cannula is used, such as those that are conventional in tracheostomy cannulas, it is possible to use an inner cannula with a congruently corrugated profile with a corrugation that optimally conforms to the corrugation of the outer cannula and advantageously stabilizes the outer cannula.

(119) FIG. 5 shows an illustrative application of the flow-optimized embodiment of the supplying lumen to the trachea-sealing balloon element 4 in a tracheostomy cannula 13. Similar to the embodiment of tracheal tubes, the volume-supplying balloon end 5 here is led to the surgically created stoma to the trachea and applied to a connector 10 below the cannula flange. The cross-sectional area G of the supplying end 5 can be selected such that, beyond the claimed requirements of a fast volume flow, it is suitable to seal the stoma and thus prevent the escape of secretions. The proximal balloon end 19 can also advantageously be configured as a bulge-like widening, which lies sealingly against the stoma directly below the cannula flange.

(120) FIG. 6 shows a tracheal tube 20, which is provided in the region of the trachea-sealing balloon segment 4 with a pressure-sensitive or pressure-measuring sensor element 21. In a preferred embodiment, the pressure sensor is an electronic component that relays its measurement signal to an electronically controlled regulator RE via a cable line 22. The sensor element preferably consists of an absolute pressure sensor. For example, sensors based on strain gauges or piezoelectric sensors can be used. The regulator RE has a bellows-like or piston-like reservoir 23, for example, which is actuated by a drive 24 and either shifts volume to the balloon 4 or removes volume from the balloon 4; the drive can consist of a step motor or can be configured as a linear magnetic drive. The control of the regulator RE is designed such that immediate compensation can be made for deviations in filling pressure in the region of the sealing balloon segment 4 by a corresponding volume shift, or the filling pressure can be kept constant at a setpoint value SW, which can be adjusted with the regulator. In this method, the sealing balloon pressure is stabilized at a point before a mechanical breath commences and before an actual volume flow of breathing gas into the patient's lungs. This is relevant especially in patients who, for example, must expend increased breathing effort after a long period of controlled machine-assisted ventilation in order to stretch an insufficiently elastic lung in the thorax to a point that triggers a volume flow of breathing air into the lung.

(121) In this phase of the “isometric” tension of the lung within the thorax and thus of the accompanying decrease in pressure within the thorax, drops in the filling pressure of the balloon can occur which are critical to the seal. In clinically apneic patients, i.e. patients who can perform (isometric) breathing but do not produce a perceptible breathing gas stream, the described sensor technology also makes it possible to ensure intubation in a manner that prevents aspiration.

(122) If sudden pressure fluctuations occur in the balloon, such as when the patient changes positions or suffers a coughing attack, the control loop described can likewise efficiently and quickly shift volume to the sealing balloon or remove volume from it.

(123) In contrast to a regulating reservoir 2, like the one described in FIG. 1 which provides a compensating reserve volume at an isobaric pressure of preferably 20 to 35 mbar, in the electronic regulation within the pressure-generating element 22 of the regulator RE it is possible to build up pressure that briefly exceeds the tracheally uncritical sealing pressure of 20 to 35 mbar and thereby accelerate the volume flow toward the sealing balloon by means of a corresponding transient pressure gradient. The continuous measurement function of the sensor thereby ensures that the pressure in the balloon does not reach critical levels.

(124) FIG. 7. In order to avoid larger deflations of the tracheal balloon segment or balloon into the reservoir, which would be critical for the seal, such as those that can occur when the patient coughs or clenches, the connecting supply line Z between the balloon and the regulator can be provided with a large-bore, flow-directing valve 25, which prevents the backflow of filling medium from the balloon BL to the reservoir R. A throttle element 26 that is not flow-directing is arranged in parallel thereto to permit the slow exchange of volume between the balloon and reservoir.

(125) FIG. 8 shows a similar application of the described dynamic tamponade, which allows a patient's esophagus to be sealingly closed by means of a fillable balloon element. The sealing balloon segment 4 transitions to a proximally elongated constriction 5 that defines a free gap S in the direction of the shaft element 3 for the flow-efficient shifting of a filling medium. The proximal elongation 5 of the balloon body optionally extends to or beyond the height of the mouth or nose placement. The elongation 5 transitions into a tube line 7 that is configured for an efficient flow and that, in turn, is coupled to a claimed reservoir or is connected to a different claimed regulating mechanism.

(126) With the devices described in the preceding figures for the flow-optimized shift of volume between a trachea- or esophagus-sealing balloon 4 and an extracorporeal regulating reservoir 2, seal-creating volume compensations can take place within a tracheal or esophageal balloon body within 10 to 30 milliseconds, preferably within 10 to 15 milliseconds, after the beginning of a change in intra-thoracic pressure.

LIST OF REFERENCE SIGNS

(127) 1 Device 2 Reservoir 3 Tube 4 Balloon 5 Proximal tapered balloon end 6 Proximal shaft element 7 Extracorporeal supply line 8 Reservoir volume 9a Distal tube end 9b Proximal tube end 10 Annular structure 11 Volume supply line 12 Constriction 13 Tracheostomy cannula 19 Proximal balloon end 20 Tracheal tube 21 Sensor element 22 Cable line 23 Reservoir 24 Drive 25 Flow-straightening valve 26 Throttle element K Force G Cross-sectional area S Gap ID Inner cross-section of the tube OD Outer cross-section of the tube GL Vocal fold plane RE Regulator SW Setpoint value BL Balloon R Reservoir