MXPA97005404A - Analysis of elimination of liquid breath - Google Patents

Abstract

The amount of respirable liquid removed from a mammal by volatilization in the lungs and / or perspiration in the skin is detected by measuring the amount of saturation of the expiratory gas with the vapors of respirable liquid, instantaneous saturation values are evaluated to determine the amount of interaction in the lungs between the respirable liquid and the respiratory gas that flows in it, and to control selected feedback operations to maintain the maximum possible amount of interaction between them, the level of expiratory gas saturation is also used to optimize parameters of operation of a breathable liquid recovery system from the expiratory gas, directly from the patient (24) or liquid fan gas (26), the expiratory gas saturation level is also used to perform studies of residual functional capacity and correct errors in conventional functional capacity measurements Residual, performed while a patient is under partial liquid ventilation, when respirable fluid is used as a blood substitute, quantifying the loss of respirable fluid through volatilization and perspiration helps determine when to replenish the respirable fluid in the blood stream; vapors of a breathable liquid form, perfluorocarbon, are used to determine the residual functional capacity of a mammalian lung

Description

ANALYSIS OF ELIMINATION OF RESPIRABLE LIQUID FIELD OF THE INVENTION This invention relates to methods and procedures for determining and controlling the amount of interaction, in a mammalian μinon, between a renewable liquid contained on the same and gas rospira + orium in the μulmon. Furthermore, it is. + To invention Lf) refers to the quanti fi cation of the perfluorocarbon volume loss (PFC) of a system. This invention also relates to methods and methods for detecting vapors of respirable liquid and employing the measured values to detect and control the respiratory and respiratory fluid recovery apparatus. other functions of the mammalian body. This invention also relates to methods and methods for detecting vapors of respirable liquid and employing the measured values to monitor the efficiency of an oxygen / carbon dioxide exchange system. BACKGROUND OF THE INVENTION respiration in the mammal occurs by gas exchange through air sacs or alveoli in the lungs, and this is known as "alveolar ventilation". Figure 1 (previous technique) shows lung passages that release and withdraw respiratory gases to and from the alveoli of lungs 200. In succession, these passages include larynx 202, trachea 204, bronchi 206 and segmental bronchi or bronchial tubes 208. Bronchioloc 208 ends in small clusters of air sacs similar to grape 210 (the alveoli) where gas exchange occurs. Figure 20 (prior art) shows an alveoli 212 of the alveoli 210 and Figure 2B (prior art) represents a diagram of the exchange of gas through the alveolus 212. A reile of blood capillaries 214 covers or surrounds the alveolar walls. 216. The interior region filled with gas from the alveoli 212 and the capillary network 214 is separated by less than 0.5 u of intermediate tissue. The exchange of gas in the alveoli of the lungs can be modeled as a ventilated deposite 208, as shown in Figure 2D. During the ventilation of liquid, the pulmonary passages of the lungs are filled with a breathing liquid that has the capacity to release oxygen to, and remove carbon dioxide from, the pulmonary system. Two common types of liquid venting processes include "total liquid ventilation" and "partial liquid ventilation". In a situation of total liquid ventilation, a respirable liquid is oxygenated and pumped or instilled into the lungs during a more breathing breathing phase. When the respirable fluid reaches the alveoli, oxygen in the respirable fluid diffuses into the blood from the capillaries surrounding the individual alveoli. Correspondingly, the carbon dioxide in the blood diffuses into the respirable liquid. Afterwards, the respirable fluid is pumped out or removed from the lungs during an expiratory breathing stage.The expired fluid is purified to remove carbon dioxide, is reoxygenated and returned to the lungs during an i nspi ratona stage. Subsequent respiration A respirator typically performs breathing steps These systems are described in U.S. Patent No. 5,335,650 and U.S. Patent No. 5,158,536, both of which are incorporated herein by reference in their entirety. In a partial liquid ventilation system, a breathing fluid is instilled into the lungs and remains there.This system is often used when the lungs are collapsed because the volume of the breathing fluid works to expand the lungs. Then, the respiratory gas is pumped into and out of the lungs, the inspiratory breathing gas that carries oxygen. geno interacts with liquid respi rabie and releases oxygen to breathable liquid. In turn, respirable fluid releases oxygen into the surrounding blood. The alveoli, in the same way as described above in the total ventilation system. Also, the carbon dioxide in the blood diffuses into the respiratory fluid, which, in turn, diffuses into areas of the lungs not occupied by the respirable fluid. The expiration gas (including carbon dioxide) exits the lung during the expl-ratone phase. As noted earlier, during partial liquid ventilation, the respirable fluid remains in the lungs acting as a means of exchange for oxygen and carbon dioxide entering and leaving the lungs. Partial liquid ventilation, as it is currently done, is not a closed circuit system. The respiratory liquids used at present have different vapor pressures. During partial liquid ventilation, a small amount of respirable liquid volatilizes or evaporates with each breath cycle, saturating the breathing gas. That is, the vapor-respirable liquid pressure causes the vapors of gas that come out of the liquid to saturate the respiratory gas while the gas flows through and around the liquid. Saturated or partially saturated gas leaves the respiratory system during the expiratory phase. Since partial liquid ventilation is not a closed-loop system, the volatilized respiratory fluid must eventually be replaced with a fresh instillation of respirable fluid into the patient's lungs. With partial ventilation of liquid, a portion of respiratory fluid due to evaporation in the lungs is also lost. Part of this evaporated liquid is absorbed by the lungs and finally from the patient's body by transpiration through the skin. There are still significant problems for total and partial liquid ventilation. During total liquid ventilation, the breathing liquid also undergoes volatilization and dissolves in the explosive liquid. The total liquid ventilation systems currently employed purge the dissolved carbon dioxide from the expiratory liquid before the gas is reoxygenated and recirculated back into the patient's lungs. This process occurs in an oxidizer / melter circuit. Not all carbon dioxide is purified from the diffuser1. In addition, no vaporous liquid vaporized in the scrubber is recovered. Rather, it is ventilated towards the environment. Therefore, the system should periodically add fresh breathing fluid from a storage tank. This increases the cost of the liquid venting process since the respirable liquid is expensive (for example, up to $ 2.00 / rnl). During partial liquid ventilation, an operator must monitor the process continuously to ensure sufficient alveolar ventilation occurs. An important aspect of monitoring is to ensure that there is sufficient amount of respirable fluid in the lungs to promote the desired amount of alveolar ventilation. Alveolar ventilation may be compromised if the volume of fluid in the lungs becomes too small. Current techniques for measuring the amount of respirable fluid in the lungs are inaccurate and inadequate.

One technique currently used includes only replenishing the umi ist or breathing fluid in the lungs until they are filled. This is supposedly done by visualizing a PFC meniscus in the endo-t racheal tube. However, it is not always necessary or convenient to completely fill the lungs to achieve the desired amount of alveolar ventilation. Therefore, the operator does not know for sure how much respirable liquid to add when the volatilization exhausts the supply of liquid. Many times, the respiratory fluid becomes distributed poorly throughout the lung due to patient movement or differences in density that cause the liquids to settle and the gases to rise. For example, some bronchioles may have little or no respiratory fluid to supply the alveoli at their distal ends, while other bronchioles may be overfilled. This maldistribution can also cause insufficient interaction between respiratory fluid and respiratory gas. Also atelectasis can cause insufficient interaction between respiratory fluid and respiratory gas. Atelectasis is the collapse of the expanded lung or the defective expansion of the pulmonary alveoli at birth. Currently, the operator of a liquid ventilation system has no safe technique to determine if insufficient alveolar ventilation is the result of an inadequate amount of respiratory fluid in the lungs, poor distribution of respirable fluid or telectasis. In addition, the liquid volatilized in the exploded gas is vented to the environment in the same way as the SLVterna of liquid ventilation. Again, this loss of a valuable substance increases the cost of the overall procedure. The inability to accurately detect the amount of respirable fluid in the patient's lungs complicates the effective management of the patient. Therefore, there is still a need for devices and methods to improve liquid ventilation procedures. Specifically, there is a need for apparatus and methods that allow the operator to more adequately determine the amount and distribution of respirable liquid in a patient subjected to partial liquid ventilation, the amount lost due to vaporization or through other evaporation channels, and the amount of interaction between breathable fluid and respiratory gases. There is also a need for apparatus and methods to purify or recover vaporized respirable liquid from the expiratory gas and monitor the efficiency of the recovery equipment. The current invention covers these needs.

Definitions The terms "pulmonary tract" and "pulmonary system" are used interchangeably herein and refer to areas of the body that are normally occupied by air during normal breathing cycles. Said areas include, without limitation, lung channels, spaces or volumes in the trachea, left and right bronchi, G bronchioles and alveoli of the lungs. The terms "respiratory fluid" and "breathing fluid" are used interchangeably herein and refer to a liquid that has the ability to release oxygen in a patient's lung system and to re-circulate it.

Lf) carbon dioxide thereof. Examples of breathable liquids frequently employed in liquid ventilation procedures include, without limitation, saline solution, perfluorinated lumenic agents, and the like. One of the currently preferred respiratory fluids are fluids from perfluorocarbon ("PFC") because at or near the normal temperature of the human body, most types of PFC liquids are relatively inert, non-biotransformable, non-toxic, and chemically and thermally stable. In addition, these liquids are especially suitable for use in liquid venting procedures due to its physiological characteristics such as surface tension (ie, approximately 75% less than that of H2O); high solubility for oxygen (this is approximately 16 times larger than that of saline); high solubility for carbon dioxide (this is approximately 3 times higher than that of saline); and relative relative inertia a. In the broadest sense, the scope of the invention includes the use of an oxygenated liquid fluorine chemical agent, of which one embodiment is a perfluorinated chemical agent such as perfluorocarbon (PFC). The PFC-as interaction, as described herein, refers to the amount of physical contact between breathing gases and a muted body of PFC (or other types of respiratory fluids).

BRIEF DESCRIPTION OF THE INVENTION Breathable liquids, such as PFC, are volatilized in the mammalian lung during partial ventilation of fluid and are eliminated from the lung through the respiratory process. Said liquids are also lost from the lung by means of evaporation, leaving the body through perspiration through the skin. The amount of PFC in the expiratory gas is a good indicator of the PFC-gas interaction. The interaction is optimal when the gas explotation is completely saturated with PFC vapor. In one embodiment of the invention, the saturation level of PFC in the expiratory gas is detected and compared with known values for different levels of saturation, thereby producing an accurate indication of the PFC-gas interaction. It also uses the saturation level to control selected r-eal operation operations of a partial liquid ventilation system to maintain the maximum possible amount of PFC-gas interaction. In the embodiment of the invention, the saturation level is used to correct errors in conventional residual functional capacity measurements made while a patient is subjected to partial ventilation of the tissue. In the embodiment of the invention, saturation iveL is used to assist in the ablation of a patient from a partial liquid ventilation system. In the invention mode, the saturation level is used to monitor and control a respiratory liquid vapor recovery system associated with a partial or total liquid ventilation system. In the embodiment of the invention, The level of saturation is used to quantify the amount of respiratory fluid in the bloodstream. This is useful for detecting transpiration loss during partial ventilation of the liquid and when the respirable liquid is used as a blood substitute. In another embodiment of the invention, PFC vapors are used to determine the residual functional capacity of a lung lung.

BRIEF DESCRIPTION OF THE DRAWINGS For the purpose of illustrating the invention, a form that is presently preferred is shown in the drawings; it is understood, however, that this invention is not limited to the arrangements and struts in precise aliases shown. Figure 1 is a representation of the prior art of pulmonary passages that release and withdraw respiratory gases to and from the alveoli. Figure 2A is a representation of the prior art of an alveolus of the alveoli. Figure 2E is a diagramatic representation of the prior art of gas exchange through the cell of Figure 2A. Figure 3 is a schematic illustration of a preferred embodiment of a thermal conductivity detector apparatus of the invention. Figure 4 is a schematic illustration of an arrangement for measuring the thermal conductivity of gases using the detector of Figure 3. Figure 5 represents graphically the zeta value and the number of Nusselt in different transport gases. Figure 6 graphically represents the zeta value and the X of PFC multiplied by the number of Nueselt for different transport gases in their saturated state and when they are completely saturated by different PFC vapors. Figure 7 represents a graph of zeta values for different volume dilutions of environmental air saturated with PFC vapor. Figure 8 graphically represents calibration values for a suitable measurement of the detector / analyzer for use in the invention. Figure 9 graphically represents zeta units and the time course to saturation for respiratory gases and for air saturated with different types of breathable liquid vapors. Figure 10 graphically represents the effect of respiratory rate on the volatilization of a respiratory liquid. Figure 11 graphically represents the effect of the respiratory rate on the volatilization of a respiratory fluid and also shows the dependence of the patient's relocation time on the rate of change of the zeta-value. Figure 12 shows a live schematic diagram m of a PFC removal analysis system for respiratory gas sampling in a partial liquid venting procedure. Figure 13 shows a system as in Figure 12 which includes a means of realigning to control the physical position of a patient.

Fig. 14 shows a system as in Fig. 12 which includes a means of repairing a PFC supply replenishment. Fig. 15 shows a system as in Fig. 12 including realization means for controlling the operation of a fan in the system of Fig. 12. Fig. 16 graphically represents zet values during an ablation process using the system Figure 15. Figure 17 graphically represents zeta values during a hypothetical session of partial liquid ventilation using the systems of Figure 13 and 14. Figure 18 shows a total liquid ventilation system that includes PFC detection and recovery apparatus. . Figure 1 < 3 shows a partial liquid ventilation system including PFC recovery apparatus. Figure 20 shows a measurement detector / analyzer used for final expiratory gas sampling during partial liquid ventilation. Figure 21 shows the arrangement of an eolenoid vent apparatus that determines the PFC-gas interaction during a partial ventilation session of liquid. Figure 22A shows an arrangement to quantify the loss of PFC by evaporation during partial liquid ventilation.

Figure 22B shows a separate part view of a collection region of the arrangement of Figure 27A. Figure 23 shows an arrangement for monitoring and controlling PFC levels in blood after PFC is injected into a patient's blood.

DESCRIPTION OF THE INVENTION Although the invention will be described in terms of a preferred embodiment, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all the documents, modifications and equivalents that may be included within the spirit and scope of the invention as defined by the appended claims. The invention described herein employs PFCs as the respiratory liquid. In this way, the following description refers to PFC liquid and PFC vapor. However, as noted above, other respirable liquids are within the scope of the invention. Figures 3 and 4 show the basic instrumentation for making thermal conductivity measurements that are employed in an embodiment of the invention to detect the amount of PFC in the expiratory gas. Figures 5-7 show theory of foundation on a parameter related to thermal conductivity (the zeta value) that is used in the invention. Figures 8 and 9 refer to measurements for calibrating the thermal conductivity measuring apparatus in the invention. Figures 10, 11, 16 and 17 illustrate studies regarding the time of zeta values during theoretical patient sessions. The apparatuses that represent the preferred modality of the system and the novel methods of analysis of the elimination of respirable liquid are illustrated in Figures 12-15 and 10-23. Figure 3 shows a schematic illustration of a portion of a detector / preferred thermal conductivity analyzer 10 employed in the invention. As noted above, the novel apparatus and method of one embodiment of this invention utilizes the principle that different gases have different thermal conductivities. The principle of thermal conductivity, applied to the thermal conductivity detector / analyzer 10 employed herein, is presented below. The thermal conductivity, K, is a measure of the heat flux through a surface per unit of time, divided by the negative of the rate of change of temperature with the distance in a direction perpendicular to the surface. Expressed differently, thermal conductivity is the index of heat transfer time per conduction, through a unit thickness, through a unit area and for a unitary difference in temperature. Therefore, it can be expressed as watts per rnetro- ° Kelv? N. It can be measured as calories per second per square centimeter for a thickness of 1 cm and for a temperature difference of 1 degree Celsius, or calopas / (crn) (sec) (° C). In this way, the heat flowing through a substance is proportional to the area of the material and the resulting temperature change over a given distance. This resulting temperature change depends on the molecular properties of the material. These include, but are not limited to, heat-specific, vapor pressure, viscosity, mass flow velocity, charge, temperature and duct diameter. To a given material at a given temperature, these properties are constant and the heat flux for a given distance can be represented as the thermal conductivity, K. The thermal conductivity detector / analyzer 10 of Figure 3 uses the above principles to determine the thermal conductivity, K, of PFCs, and of respiratory gases. The detector / analyzer 10 uses a dual chamber design. Fi gas flows at a known speed and at a given temperature through chamber I (the active cell). The TI chamber (the reference cell) opens to the atmosphere without flow through it. The thermal resistances 14 (Ti) and 16 (T2) are heated to a known temperature. The gas flow in the chamber T changes the temperature determined by Ti in relation to T2 - This temperature gradient is converted into an analog voltage, it is processed by means of an A / D converter and is represented as a digital output. The thermal resistances 14 and 16 may be identical.

The scope of the invention also includes other configurations of thermal resistance to detect thermal conductivity. The detector / analyzer 10 is calibrated using 100% oxygen and oxygen as the standards. These gases are chosen due to their thermal conductivity properties and to certain expep mentally. The air, composed mainly of nitrogen, has a negligible thermal conductivity and thus registers a small temperature gradient between the thermal resistances 14 and L6. In this way, no voltage occurs and the output is approximately 0.00 V. In contrast, the significantly higher thermal conductivity of oxygen at 100% produces a temperature gradient that results in an output of approximately 1.58 V. These two outputs They are used as calibration standards. The output digital signal of the detector / analyzer 10 is given as a zeta value or zeta unit (Z), which is proportionally related to the voltage that originates from a change in temperature per unit length. It reflects the concentration of a gas measured in a sample. The magnitude of temperature change is based on the different intrinsic thermodynamic properties of the measured substance. The zeta unit is equal to the voltage output described above, plus approximately 8.4. The zeta unit is thus only an arbitrarily created value of thermal conductivity used to generate trend charts and to establish alarm and control functions. l I-i gure 4 is a schematic illustration in v11ro (A provision for measuring the thermal conductivity of different gases using the detector of Figure 3. Fl gas enters the pump L8 that turns the gas in the space above 70 of the container- or closed flask 22. The flask 2 is partially filled with PFC liquid 23. The liquid vapor of PFC 23 saturates the gas flowing through the upper space 20. The saturated gas flows out of the ground 77 and through the thermal conductivity detector / analyzer 10. The system The measurement used in Figure 3 and 4 uses forced gas convection through a conduit.For forced convection, heat is transferred from a solid heat source to the gas flowing by means of conduction and / or convection, depending on the The flow characteristics can be characterized by the Reynolds number, symbolized as NRβ, an adirnensional number equal to the density of a fluid, by its velocity, by a characteristic length, divided by re the viscosity of the fluid. In this system, it is expressed as: NR, - r (D / μ) x (4G / trd) 1 (Equation 1) where D is the gas density (gm / ml), μ is the viscosity of the gas (gm / cm sec), 0 is the flow velocity (ml / sec), and d iq is the diameter of the duct (cm). When the Reynolds number is greater than 3000, the flow is considered turbulent. When the Reynolds number is less than 3000, the flow is considered the i ar. The dynamic properties of the fluid also dictate by itself the amount of heat transfer in a system. These terrnodynamic principles can be described by means of the Prandtl adnnensional number. In mechanical flow, the Prandtl number, symbolized as Prm, is equal to the kinematic viscosity divided by the molecular di usivi. In thermodynamics, the Prandtl number, symbolized as Npr, is equal to the dynamic viscosity by the specific heat at constant pressure divided by the thermal conductivity. For the purposes of this system, the Prandtl number is expressed as: Npr - CPμ / l- '(Equation 2) where CP is the specific heat of the substance (cal / grn ° C), μ is the viscosity (gm / cm sec), and K is the thermal conductivity (cal / crn sec ° C): The heat transfer can be evaluated by means of the adi ensionai number of Nusselt. In thermodynamics, the Nusselt number, symbolized as NU, gives a measure of the ratio of the total heat transfer to the conductive heat transfer, and is equal to the coefficient of heat transfer by a characteristic length ded by thermal conducty. In the practice of engineering, the number N? Sselt for flow in conduits is usually evaluated from empirical equations based on experimental results. As a result, the forced convection heat transfer relationship can be correlated with The following equation: NNU - x { (NRe) a (Npr) b} (Equation 3) where x is a constant number and a and b are exponents that are determined exponentially for the Reynolds number and the Prandtl number, respectively. The flow conditions determine the value of a and b. The Nusselt number for each respective gas measured in the system will determine the ze value for that gas. The number of Nusselt for respiratory gases can be calculated based on the following equation: NNU (NR «) (NPr) (Equation 4) which is simplified to: NU = P Cp / I '(Equation 5) A correlation was established between the number of Nusselt and the zeta value measured in the form of the following equation (r = .93, regression of first * order): zeta = 73.2- (15.6 NNU) (Equation 6) Figure 5 graphically represents the zeta unit and the Nusselt number for the following gases: 90% of Ai re, 10% of He 4% of Ai e, 5% of He 100% of Oxygen 100% of Ambient Air 100% of Nit rog no The measured zeta units were used to calculate the Nusselt number for different PFC-gas mixtures including: Air completely saturated with steam APF-140 Air completely saturated with PFOB vapor (perf luoroctilo ida) Air saturated with RirnarTM vapor at saturation percentages of 100%, 75%, 50% and 25%. 100% oxygen completely saturated with APF-140 vapor. 100% oxygen completely saturated with PFOB vapor.

LOp oxygen completely saturated with steam - Rimar 1"M E: L APF-140 is known generically blunt PP5 and RirnarTM is generically known as FC-75. Rimar l ~ M is manufactured by Miteni Corp., Milano, Ttalia (Represented in the United States of America by Mer * cant? Le Developrnent Inc .. Bridgetown, Connecticut). FC-75 is also manufactured by 3M Company, St. Paul, Minnesota. Since each PFC has different vapor pressure, each will have different percentages of volume in saturated gas. For example, FC-75 having a vapor pressure of 57 rnrn Hg will occupy 8.0% (57 m Hg / 713 m Hg) of a saturated gas, while that PFOB with a vapor pressure of 11 mg Hg will occupy only 1.54% of a saturated gas. Therefore, the number of Nusselt for a PFC-gas mixture must be multiplied by the volume percent of the PFC vapor. This tells exactly the difference in percentage only of the carrier gas. Figure 6 graphically represents zeta values for different transport gases in their unsaturated state when they are completely saturated with three different PFC vapors. The graph shows how the zeta value varies based on the volume percentage of the PFC vapor in the carrier gas. Figure 6 shows that the change in percentage to par of the baseline by means of the addition of different PFCs is identical for the three different transport gases (nitrogen, oxygen and air). Theoretically, this relationship can be applied to any carrier gas. Figure 7 graphically represents value-is zeta par-a different dilutions in volume of ambient air saturated with PFC vapor type FC-75. More specifically, the volumes of environmental air were diluted with different vapor percentages of FC-75 and their respective zeta values were recorded. The serial dilution of environmental air with increasing vapor volumes of FC-75 was generally linear, from 0% (unsaturated ambient air) to approximately 100% (fully saturated air). The data point at 0.00% in volume represents installed air. The data point at approximately 0.063% by volume represents fully saturated air. The data points were extrapolated to generate * a straight-line function, zeta = a (Vol%) + b, where a is The slope of the line and b is a const ante. This ratio i n v 11 ro can be extrapolated to the in vivo data. To the extent that the vapor volume of PFC diluted in the air decreases, the zeta value approaches 100% of the transporter gas. In this way, as the PFC-gas interaction decays in the lungs, the percentage volume of the PFC vapor in the expired respiratory gas decreases, and the zeta value will approach approximately 8.4 Z. This ratio allows an operator to monitor the volume ( that is, the amount of liquid) of liquid PFC in 2? The lungs that are lost from the respiratory process over time during the partial ventilation of fluid, this information is used to control the replenishment of the PFC liquid in the lungs. Alternatively, a double revision of the PFC information is used as a monitoring of the zeta trend line, as will be described in more detail below. To convert the volume percentage information into the aiie (derived from the measured zeta value), the volume percentage is first converted to the value of the PFC liquid quantity by multiplying the volume percentage in the air by a constant that represents the amount of liquid (in liters) of PFC in a known volume of PFC vapor at the measured temperature. During the session of partial liquid ventilation, the instantaneous flow rate of expired respiratory gas and the zeta value are measured and recorded continuously. This information allows a computer to generate the instantaneous velocity of PFC liquid loss. The instantaneous velocity of liquid loss of PFC is then integrated with respect to the time to obtain the total loss of liquid of PFC by volatilization. The total loss value is then adjusted to consider the small amount of PFC liquid lost by evaporation in the blood stream. An appropriate algorithm for determining the volume loss of PFC is as follows: Loss of PFC-Vrx (% Vol of PFC) x time x CLV (Equation) Where Vr is volurnet ventilation rich in volneric units / per time. Vr is equal to the oxygenator pump flow when quantifying the PFC loss of a total liquid ventilation system. Vr is equal to the ventilation of the moment when the loss of a patient's PFC is quantified (also known in the art as VM). CLV is a conversion factor 11 qui do / vapor. Previous experiments have shown, for example, that 86 i of PFOB vapor is equal to 1 ml of pure fluid and that this ratio is constant during a temperature scale of zero degrees Celsius at 37 degrees Celsius. This relation is made based on the calculation of the molar fraction of PFC in a transport gas in dónle: Molar Fraction = (22.4 moles of gas / liter) x (300 ° Kelvm / 273 ° Kelvin) x (Specific Gravity / Weight (in grams)) (Equation 8) The% by volume of PFC in equation 7 depends on the percent saturation of the carrier gas and the vapor temperature. As is well known in the art, this value must also be corrected for variations in absolute pressure and water vapor pressure. To determine the rate of loss of PFC, time is removed from equation 7.

Experimental data have shown that the presence of carbon dioxide in the expired respiratory gas does not significantly alter the zeta values, which would happen if the patient was only breathing pure air. If the patient breathes pure oxygen instead of air, a different straight-line zeta function is used. Once the PFC volume percentage is determined, the calculations proceed exactly as described above. Likewise, a different straight line zeta function is used if a different type of PFC is used. Figure 8 graphically depicts the normal calibration for the detector / analyzer 10. As indicated above, 100% air and oxygen are used as the standards. Ambient air is flowed through the detector / analyzer 10 in the period from A to B, followed by 100% oxygen (period B through D), followed by a return to ambient air. Figure 9 graphically represents the zeta units for selected respiratory gases and for air saturated with different types of PFC vapors. The lapse of time to saturation is also included. Figure 10 graphically depicts the effect of respiratory rate (i.e., respiratory velocity) on PFC volatilization. In this scenario, the ventilator delivers pure oxygen and the patients' lungs are filled with PFC fluid type FC-75. The zeta-value begins to saturation of 100% since the oxygen in the gas 77 Expired respiratory system is completely saturated with steam FC-75. As time passes, the amount of liquid PFC in the lungs slowly depletes as it volatilizes. Finally, the level of oxygen saturation begins to decline *, thereby causing the zeta value to approach the value-for pure unsaturated oxygen (ie, 10.0 Z). As expected, the upward trend toward the unsaturated oxygen value is more than required for a respiration frequency of 40 cycles / rnin? T or for a respiratory rate of 20 cycles / minute. Since a faster breathing rate results in greater alveolar ventilation, this graph indicates that the volatilization of PFC is positively correlated with alveolar ventilation. That is, the greater the alveolar ventilation, the greater the volatilization of PFC. Figure 11 graphically depicts the effect of the respiratory rate on the volatilization of PFC and also shows the time dependence of the patient's relocation on the rate of change of the zeta value. In this context, the ventilator delivers pure oxygen and the patient's lungs are filled with PFC fluid type FC-75. The zeta-value starts at 7.8 Z (100% saturation) since the oxygen in the expired respiratory gas is completely saturated with FC-75 vapor. As time passes, the amount of liquid PFC in the lungs slowly depletes as it volatilizes. The zeta value in this way slowly approaches 10.0 Z (0% saturation), in the same way as shown in Figure 10. Returning first to the trend line for a respiratory frequency of x cycles / minute, the line Trend suddenly turns sharply upward to approximately 140 minutes. That is, it sharply increases dZ / dt, thereby indicating that the level of oxygen saturation is falling rapidly rather than gradually. This indicates that the amount of interaction in the lungs between the liquid PFC and the oxygen has suddenly fallen. One possible reason for this sudden drop is that the liquid PFC has poorly distributed in the patient's lungs. At approximately 150 minutes, the patient is relocated to try to distribute more evenly the liquid PFC in the lungs. Shortly thereafter, the zeta value falls again steeply and continuously along a more continuous upward trend line. This indicates that the liquid PFC was actually poorly distributed in the lungs. After this situation was corrected, the amount of interaction in the lungs between the liquid PFC and oxygen increases significantly, thereby increasing the level of oxygen saturation and decreasing the zeta value of the expired respiratory gas. Returning again to the trend line for a respiration frequency of x + and cycles / minute, this is relatively continuous until a little after approximately 230 minutes. At this point, the patient is relocated and the zeta-value falls briefly before resuming a continuous upward trend. In this case, the poor distribution of liquid PFC occurred so gradually that the trend line does not show a rapid increase, as in the 1 trend trend of x cycles / minute. Figure 12 shows a schematic and live diagram of a PFC elimination analysis system for sampling respiratory gas in a partial liquid venting procedure. The trachea of a living being, such as an animal or patient 74, is connected to a respiratory gas ventilator 76 via an endotracheal tube 28 such as a tracheal tube HILO JET ", manufactured by Mali mcl-rodt Medical, Tnc, St Lotus, Missouri The open end of this tube 28 is connected to the ventilator 26 which maintains the breathing function by pushing vent gases in and out of the patient 's lungs, one version of this tube 28 has two. different side doors A first door 30 is proximate to the middle part of the tube 32 and the second door 34 is distant from the middle part 32. The first door 30 is in fluid communication with the entrance of a sampling path 36 and the second door 34 is in fluid communication with the outlet of the sampling path 36. In this way, the rail path 36 is a continuous closed-loop flow path for continuously sampling the respiratory gas flowing through the tube 28 and returning the sampled gas back to the tube 28. Therefore, there is no net gas added or removed from the patient 24. This scheme also does not cause any physiological disturbance such as a decreased partial pressure of oxygen or a high partial pressure of carbon dioxide. The sampling path 36 comprises, in sequence, the influencer tube 38, the circulation pump 40, the thermal conductivity detector / analyzer 10 and the return tube 42. The inflow tube 38 allows fluid communication between the circulation pump. +0 and the first door 30, while the return pipe 4? it allows fluid communication between the LO detector / analyzer and the second door 34. The detector / analyzer 10 outputs a zeta value, as described above. A register 44 is connected in parallel to the detector / analyzer 10 to record the calculated zeta value in the detector / analyzer 10 at discrete periods. The sampling path 36 may optionally include a fluid trap 46 between the distal end 48 of the inflow tube 38 and the inlet end of the pump 40 to prevent * fluid, mucus, or other liquid or solid substances from entering the lung. the pump 40 and the detector / analyzer 10. The detector / analyzer 10 may also additionally include a series connection of an inverter 50 and a high pass filter 52 to provide clarification and deflection of the positive signal of the output signal before its output is sent to the zeta recorder 54. FIG. 12 also shows the flow meter 56 for continuously measuring the instantaneous flow velocity of the expired respiratory gas. The instantaneous velocity of flow and the. The value of the percent saturation of PFC at each instant is sent to a computer to generate the instantaneous rate of loss, as well as the total volume loss of liquid PFC of the lungs. Subsequent figures show applications of the flowmeter 56. Figures 13-15 show how the digital output of the zeta value of the detector / analyzer 10 is employed to alert an operator and provide selected functions of feedback control. In Figure 13, the zeta value controls the physical position of the patient 24. In Figure 14, the zeta value determines whether the return tube 42 should be removed from a PFC liquid reservoir to replenish the PFC in the patient's lungs. In FIG. 15, the zeta value controls the operation of the fan 26. Returning to FIG. 13, the zeta value is connected to the input of the central processing unit (CPU) 58. The CPU 58 is previously programmed with information to determine if the operator is warned by a screen or audible or visual alarm 60 that the zeta value, or the rate of change of the zeta value (dZ / dt), is outside a given scale. The CPU 58 is also pre-programmed with instructions on how to respond to off-scale conditions and present appropriate control signals for feedback to the controller 62. A possible response is to alert the operator by means of the alarm / screen 60 for relocation of the controller. the patient bed 64 or automatically control a bed location motor 66 to perform that function. Figure 14 shows the feedback controller 62 connected to a PFC resistor 68. If the relocation of the bed does not improve the PFC-gas interaction, the CPU 58 instructs the real-time controller 52 to release more PFCs in a patient's lungs, allowing the PFC of the reservoir or 6R to enter the return tube 42 of the reservoir. sampling path 36. FIG. 15 shows the actual pin controller 62 connected to the ventilator * 26 to cause the ventilator 26 to increase its respiration velocity or inspiratory pressures. The control realigning functions shown in figures 13 and 14 are more appropriate during partial liquid ventilation, whereas the function shown in figure 15 is more appropriate during ablation of a patient, from total ventilation of liquid to conventional gas ventilation. When a patient is ablated from total fluid ventilation, a residual amount of PFC fluid will remain in the lungs. Finally, the residual PFC will be completely volatilized. However, if the residual PFC takes a long time to volatilize (as indicated by a zeta value that takes too long to reach the value for pure unsaturated vent gas), the feedback controller 62 may cause the fan 26 to increase your breathing speed or inspiratory pressures. This will increase the amount of alveolar ventilation, and thus more rapidly promote the volatilization of PFC. The application of the control function in FIG. 15 is better understood with respect to FIG. 16 that graphically represents zeta values during the ablation process. At zero minutes, liquid ventilation with liquid PFC type FC - 75 has ended and conventional gas ventilation with ambient air has begun. The residual PFC in the patient's lungs volatilizes and saturates L?) Partially expired respiratory gas. This results in a zeta value of approximately 7.0 Z, which is between the 8.4 Z value of the ambient air and the 6.7 Z value of the air completely saturated with FC-75. As time passes, the amount of liquid PFC in the lungs is exhausted slowly to volatilize and evaporate from mis o. Since PFC is not being added, the zeta value tends up to 8.4 Z (the value for unsaturated ambient air). Since the procedure of ablactation of total ventilation of liquid to conventional gas ventilation must be 70 relatively fast (for example, approximately 30 to 60 minutes), the solid line trend line shows the desired progress of the zeta value. However, if the volatilization is occurring very slowly, due to insufficient alveolar ventilation, the trend of the line will appear as shown on the dotted line. Mathematically speaking, this occurs when the slope of the trend of the line, dZ / dt, is below a predetermined value. The CPU 58 is programmed to detect this condition and to increase the respiratory rate or mspi raton pressure of the ventilator 26. In the ablation procedure shown in FIG. 16, the CPU 58 determines after approximately 12 minutes that the volatilization is proceeding too slowly. Corrective action becomes and shortly thereafter, the trend of the dotted line merges with the desired trend of the continuous contour line. From the trend information of the line in Figure 16, the amount of PFC left in the lungs and the time course of volatilization (using the algorithm of equation 7) is easily derived. Until now, there are no exact or even theoretical means to correctly determine these parameters. The application of the control functions in figures 13 and 14 are better understood with respect to figure 17 which graphically represents a hypothetical session of partial liquid ventilation. In the scenario depicted in Figure 17, the ventilator supplies air and the patient's lungs are filled with PFC fluid type FC-75. The zeta value starts at 6.2 Z, since the expired respiratory gas air is completely saturated with FC-75 vapor. As time passes, the amount of liquid PFC in the lungs slowly depletes as it volatilizes and evaporates from the lung. If the ventilation arrangement is left alone as the arrangement shown in Figure 10, the zeta value would approach and finally stabilize at 8.4 Z (the value for ambient air, saturated). However, unlike the test arrangement in Figure 10, measurements are taken continuously to maintain the zeta value at the fully-saturated value of 6.2 Z or close to it. This is because when the air is completely saturated, maximum gas-PFC interaction occurs, and in this way maximum alveolar ventilation. Therefore, the trend of the line will be relatively flat (dZ / dt average = 0) during the ventilation session. (For purposes of illustration, the zeta value scale in Figure 17 is greatly exaggerated, thereby causing the slope of the line trend to appear steeper than it actually is). During the first 80 minutes of the session, the zeta value gradually increases from 6.2 Z. The CPU 58 in Figure 13 is set to take corrective action once the zeta value exceeds approximately 6% of its desired value. In this way, when the zeta value reaches 6.6 Z at 80 minutes, the CPU 58 alerts the operator by alarm / screen 60 with a signal such as "OUT OF SCALE PFC LEVEL, RELOCATE THE PATIENT OR ADD ADDITIONAL PFC". Alternatively, the feedback controller 62 will automatically send a signal to the bed location motor 66 to relocate the patient. In the hypothetical session represented in Figure 17, varying the location of the bed, the zeta value returns to an acceptable amount. At 160 minutes, the zeta value is again outside the scale. The bed is relocated but this time it fails to return to the value within the scale. The CPU 58 detects that the zeta value is not declining and determines that it is necessary to add additional PFC. The operator is alerted to perform this function, or the real unentactlon controller 62 automatically releases more PFCs to the patient's lungs, as described in Figure 14. Although the systems in Figures 13-15 are illustrated separately, It is understood that a single system may include a control type of real Lmentaoion.

Recovery of PFC The breathable liquid, such as PFC, is volatilized from a diffuser / condenser circuit during total liquid ventilation. The expired breathing fluid is purified to remove carbon dioxide, is reoxygenated and is returned to the lungs during a subsequent inspiratory breathing phase. Usually, the breathable liquid vaporized in the expiratory liquid is not recovered during this process. Rather, it is ventilated towards the environment. Therefore, the system must periodically add more respirable fluid from a storage tank. As indicated before, the loss of respirable fluid in this process is expensive. Figure 18 shows a Total Liquid Ventilation System (TLV) 70 that uses PFC as the respiratory liquid. The system 70 recovers PFC from volatilized respiratory liquid, which can escape upstream to the environment. In addition, the system 70 uses the thermal conductivity of the PFC, measured in zeta units, to monitor and control the efficiency of the recovery process. The TLV 70 system includes a capacitor circuit * 72 connected in par-allele with an oxygenator / di fusor? 4. Oxygenator / di fuser 74 includes an O2-CO2 membrane 76, as is well known in the art, to remove dissolved gas from the expiratory liquid flowing therethrough. By pumping the PFC through the oxygenator / diffuser 74 by means of the pump 78, the corresponding PFC vapor travels to the condenser 72 through the path 80. The capacitor circuit 72 includes a condenser 82 to capture the vapor of PFC by cold condensation and a condenser thermostat 84. The recovered PFC fluid is then reintroduced into the expiratory tank of PFC 06. Two important factors determine the amount of PFC vapor loss of the TLV 70 system (and thus determines the efficiency of the TLV 70 system in the recovery of PFC). An important factor is the pump flow through the oxygenator / diammer 74. Another important factor is the operating condition of the elements of the capacitor circuit 72. For example, the vapor loss of PFC is proportional to the pump flow of the pump. oxi genador / di fusor- 74. The TLV 70 system uses detector / analyzer 10 'of thermal conductivity to track the process of vapor recovery. A pump 88 removes gas samples from the path of capacitor-87 and flows it through the detector / analyzer 10 'to obtain a voltage level correlated with a zeta value. The value of zeta is sent to CPU 90 for analysis. If the CPU 90 determines that the zeta value is outside a predetermined range, it sends a signal to feedback to the compiler 92 to take appropriate corrective action. One type of action is to increase or decrease the flow of the pump in the pump 78 of the oxygenator / diammer 74. Another type of action is to modify-conditions of operation of the elements of the capacitor circuit 77. The continuous feedback control determines The most efficient amount of pumping flow and operating conditions of the condenser. Of course, the goal of the realigning circuit is to minimize the amount of PFC vapor in the gas sample withdrawn (determined by the zeta value) without compromising other functions of the TLV system 70. In the embodiment of the invention shown in Figure 18, the capacitor circuit 72 includes a capacitor thermostat 84 with a variable attachment point. In this way, the modified operation condition in this mode is the fixation of the condenser thermostat 84. It is raised or lowered to achieve optimum vapor recovery. Other known ways to improve the efficiency of the capacitor 82 include the application thereto of ultrasound or vibrations. Although the described embodiment fits only the condenser thermostat-84, the scope of the invention includes all known methods for the different operating conditions of the elements of the capacitor circuit. In this way, instead of, or in addition to, adjusting the thermostat of the capacitor * 04 in response to a real control control, the ultrasonic or vibration level can be adjusted. With this system it is easy to monitor the recovery of PFC. The total amount of liquid PFC in the expiratopo reservoir 86 and the inspiratopo reservoir 94 will remain constant if the PFC recovery is 100% efficient. The output of the tank level indicators (not shown) is connected to the CPU 90 to monitor the recovery quantities. If the recovery efficiency falls significantly below 100%, the tanks will need regular refilling. The filling speed will be proportional to the recovery efficiency. Figure 19 shows a partial liquid ventilation system (PLV) 96, using PFC as the breathable liquid. The system 96 employs the same capacitor circuit 72 of FIG. 18 to recover volatilized PFC from the expired respiratory gas. Likewise, the system 96 uses the thermal conductivity of the PFC vapor to monitor the efficiency of the PFC recovery process and adjust the operating conditions of the elements of the capacitor circuit 72. PFC recovery efficiency is measured in one of two ways. In one scheme, the PFC vapor is detected in the sample path 36 and in the output path of the capacitor 82. The zeta values of the two samples are compared to determine how well the capacitor circuit 77 is recovering the vapor of PFC. In another scheme, the zeta-value of the samples, detected in the capacitor output path * 82, are used (see the calculation method described above with respect to FIG. 7) to determine the total amount of liquid PFC It is not being recovered. The amount of liquid not recovered is compared to the amount recovered (that is, the amount of PFC liquid condensed by the condenser 82) to determine the recovery efficiency. The output of the level indicator of the reservoir 98 is connected to the CPU 90 to monitor the recovery quantities. Of course, the CPU 90 uses the zeta value of the detector / analyzer * 10 'to continuously adjust the operating conditions of the capacitor circuit 82 for maximum achievable efficiency.

Final expiratory gas sampling Figure 20 shows how the thermal conductivity detector / analyzer * 10 is used for final expiratory gas sampling during partial liquid venting. At the end of the expiration, a volumetric syringe 100 with upper space withdraws gas expiratopo from the inflow tube 102 connected to the endotracheal tube L04. (The endotracheal return tube 106 is left unconnected). The content of the syringe is then injected at a constant flow rate in the detector / analyzer 10 and the zeta value is determined. Then, the zeta value is extrapolated to determine the PFC-gas interaction or used for respiratory gas measurement. In cases of respiratory problems, this may be the preferred method of analysis because the sampling time is at a minimum.

Node Sun Breathing Figure 21 shows how the PFC-gas interaction is determined using a solenoid vent apparatus arrangement 108 during a partial liquid venting session. The apparatus 108 includes fan 110, vent 112 and three-way solenoid valve 114 connected therebetween. The animal or patient 116 breathes in and expires venting gas through the solenoid valve 114. Then, the solenoid valve opens toward the vent 112 and simultaneously closes the path to and from the ventilator 110. The vapor * of PFC of PFC volatilization flows into the gas at vent 112. Finally, that gas is saturated with PFC vapor. After saturation, the solenoid valve 114 is diverted back to the fan mode 110. The thermal conductivity detector / analyzer 10 measures the gas and outputs a zeta value output to the CPU 117. The CPU 117 calculates the rate of change of the zeta value with time, dZ / dt, which provides an indirect measurement of the PFC-gas fraction. The instantaneous slope is a function of the PFC-gas interaction. The faster the exchange rate reaches equilibrium, the greater the PFC-qas interaction. In this way, a large slope indicates significant interaction, while a small slope indicates relatively little interaction. This measure of the efficiency of the interaction can be used in place of the on-line system shown in Figure 12. Figure 21 shows two graphs of trend A and B representing different sessions of partial liquid ventilation. The respiratory fluid is PFOB. In the trend graph A, the slope of the trend imeci (dZ / dt) between the time that the solenoid valve 114 deviates between the fan 110 and the vent 112, to, and the full saturation time, tf s, it is significantly smaller * than the slope of the trend line between those same points in time in the trend graph B. In this way, the PFC-gas interaction in session B is greater than in session A. the system shown in figure 21, the trend graph starts at a zeta value for air 18.4 Z) and stabilizes at the value for air fully saturated with PFOB vapor (7.8 Z).

Evaporative loss of PFC Figure 22A shows how the PFC vapor levels are used to quantify the evaporative loss of PFC during partial liquid ventilation. As described in the previous background section, a portion of respirable liquid (eg, PFC) is lost due to evaporation in the lungs. This evaporated liquid is absorbed in the lungs and diffuses into the blood near the lungs and around the alveoli. Finally, it leaves the patient's body through transpiration through the skin. A gas collection device 118 is attached and / or pressed against the skin of an animal or patient 120. The device 118 can be a skin patch or a collection bottle. Figure 22B shows a separate part view of the collection region and a simplified illustration of the device 118 against the outer surface of the skin 119. A small stream of gas flows through a sampled region associated with the area of the device 118. The gas that flows into the region is pure (ie, saturated with PFC). If there is a possible loss by evaporation of PFC from the skin, the gas flowing out of the region will have a detectable saturation level. This gas flow outlet of the device 118 is connected directly to the thermal conductivity detector / analyzer 10 to detect the saturation level. To quantify the evaporative loss of PFC from the sampled region, equation 7 is used, where VR is the gas flow of the maestrea region Ja. It is important to know the amount of evaporative loss because it improves the accuracy of the amount of PFC liquid that is known to be in the lungs, the amount in the lungs is equal to the amount that originally entered monkeys. The amount volatilized, the amounts evaporated amount. The volatilized quantity is calculated from the sampled zeta values of the endofque tube. The evaporated quantity is related to the luteal value determined from the schema in Figure A. To quantify the total evaporative loss of PFC throughout the body, the evaporation determined from the sampled region is extrapolated. For example, if the device 118 is a skin patch, the skin patch will cover a known percentage of the total surface area of the skin. Will the evaporation of the surface area of the skin patch be, in this way,? n known percentage of total evaporation of the body. The surface area values of normal skin are known for humans of a certain age, size, weight and the like. During the partial ventilation of liquid, the evaporative losses are very small in comparison with the losses of the respiratory system. For example, evaporative losses may be 1/50 of the amount lost from the respiratory system. However, accurate quantification of the total loss of PFC during partial liquid ventilation should preferably include the amount lost by evaporation.

PFC-Blood Substitute It has been found that PFC emulsions are an adequate substitute for blood, capable of dissolving oxygen and carbon dioxide. However, when PFC is used for this purpose, evaporative loss occurs through the skin and respiratory system (for example, the lungs). Exists? the need to quantify this loss evaporates v. The level of PFC vapor in the lungs is related to the ovaporative loss, and thus indicates when the PFC should be replenished into the bloodstream.Figure 23 shows a provision to monitor and control * levels of PFCs in blood after the A patient's blood 24 is injected with PFC The expired respiratory gas containing PFC vapor flows through the endo-tracheal tube 28, is pumped through the retinal path 36 and is measured by means of the conductivity detector / analyzer 10. The detector / analyzer 10 sends a signal to the CPU 58. The CPU 58 is programmed to indicate when the PFC vapor in the lungs reaches a pre-selected level and alert an operator or automatically add PFC to the bloodstream of the patient through the feedback controller 62. The feedback controller 62 causes the PFC of the reservoir 68 to flow into the intravenous tube 122 connected to the vein of the patient. Alternatively, can ex sampling be used? final vaporizer of PFC in the lungs, as shown in Figure 20, instead of sampling path 36, and the results can be sent to CPU 58 of Figure 23. In the arrangement shown in Figure 23, patient 24 breathes through the gas fan 26. However, patient 24 does not need to be attached to the assisted breathing device. It is only necessary that there be a means such as, but not limited to, the endotracheal tube 28, a nasal CPAP (positive continuous ventilation pressure), a mask or the like to collect a sample of the expired respiratory gas for analysis. Equation 7 is used to detect the loss of PFC. Again, the arrangement in Figure 22A can be used to detect the amount of transpired PFC during the replacement of blood with PFC. Then, this amount is added to the amount left by the patient through the lungs to determine the loss of the total amount of blood flow.

Residual functional capacity The thermal conductivity detector / analyzer 10 can also be used to correct conventional measurements of the residual functional capacity (FRC) of the patient's lung and to measure FRC in a new way.

FRC is the volume of gas remaining in the lung (ie, lung volume) at the end of normal exhalation or expiration. Traditionally, a helium dilution test is used when FRC measurements are made. This test uses thermal detectors. The output of the detectors will be erroneous if a respirable liquid such as PFC is present in the expired gas. When a patient is subjected to partial liquid ventilation, the PFC vapor will be present in the expired gas due to PFC liquid volatilization. In this way, the FRC policy will be erroneous. To correct this error, the LO detector / analyzer output value is used to detect * the amount of PFC vapor in the lung. Then, this value is used to compensate and normalize the FRC value measured conventionally. In addition, the PFC vapor can be used instead of € > helium, as the diluent or tracer gas to make a FRC measurement. Since helium is soluble in the blood, large amounts of helium are absorbed during this measurement. The steam of the PFC is an ideal gas to make * said measurement since it is inert and is minimally absorbed in the circulation (FRC < Helio). To carry out this measurement, the patient breathes from a bag of known volume and contains a known quantity of the PFC vapor. The FRC is calculated using the following equation which is a modification or rearrangement of Fick's law: FRC = i [(d / Cf) - 11 (Equation 9) where Vi is the volume of the system (that is, the volume of the balls), Ci is the initial concentration of PFC vapor in the bag, and Cf is the final concentration of PFC vapor in the bag. The volume «Jel system Vi, + arnb? N was determined by * rearrangement of Fick's law. In this way, exactly different known volumes of the syringe can be determined. The final concentration of PFC vapor in the bag, Cf, it is determined by turning a sample with the syringe and using the arrangement shown in Figure 20. The resulting zeta value is then correlated with the percent concentration using information from the graph in Figure 7. PFC vapor is also suitable to be used as a tracer gas for other types of lung function evaluations including the removal of static volumes of the lung, including residual lumen and total lung capacity. PFC vapor is less expensive than the current diluent gases usually used in these tests. The PFC vapor can be used in the normal equipment used for individual entrainment and breathing techniques (either closed or open circuit) present in many hospitals. PFC vapor can also be applied in gas mixture analysis for ventilation distribution in obstructive pulmonary disease.

Radiological Diagnosis Certain respiratory fluids such as PFC are radiopaque and make ideal contrast agents for high-resolution computed tomography (CT). In this way, a CT scan of the lungs, made during partial liquid ventilation, provides an image of the PFC in the lungs. The image is used to determine the distribution of PFC in the lungs. However, the scan can be misleading because it does not distinguish between PFCs in the alveolar spaces and PFCs in the pulmonary interstitium. The thermal conductivity detector / analyzer 10 can be used in conjunction with CT to solve this problem. The PFC-gas interaction level is determined either before or after the scan, thus providing correlation with the doctor's diagnosis. A high level of interaction indicates that a significant amount of PFC, which appears in the CT scan, is in the alveolar spaces, while a low level of interaction indicates that the PFC is mainly in the pulmonary interstitium.

Agents Released by PFC and Therapies The thermal conductivity detector / analyzer 10 can be used during pulmonary drug administration (PAD). During PAD, the vapor level of PFC in the lungs can be used to estimate the bioavailability of the relevant pharmacological or anesthetic agent. The exact determination of the PFC-gas interaction and the relative amount of PFC in the lungs is also important during intrathaeal instillation of PFC for treatment of meconium aspiration syndrome (MAS), congenital diaphragmatic hernia (CDH), respiratory distress syndrome neonatal (NR S), and other pulmonary pathologies. Figure 3 shows a type of suitable thermal conductivity detector of the invention. However, other types of thermal conductivity detectors measuring the conductivity of respiratory gases are also within the scope of the invention. The systems and methods described above employ a thermal conductivity measuring device to determine the PFC-gas interaction. However, other types of Lens analyzers can be used, including a spectrophotometer or gas chromatograph instead of the thermal conductivity detector / analyzer 10. These devices are equally capable of distinguishing between PFC vapor and other types of gases (eg. example air, oxygen) due to differences in electronic density. However, they are less effective in terms of cost than the measurement device currently described. In addition, as is well known in the art, the elements of the thermal conductivity detector / analyzer 10 can be used to measure other properties of the gas flowing therein., including mass or pressure. For example, if thermal resistances are used in a mass flow detector, the zeta value varies with the mass of the sample. Then, the zeta value should be calibrated with gases of known quantities in percent saturation of PFC in the same way as the thermal conductivity detector / analyzer described in the foregoing, that is, the second axis of the Y , in the figures LO, Ll, 16 and 17, marked as "saturation percentage with PFC" will be shifted upwards or downwards so that they correlate appropriately with the appropriate zeta values, in this way, the zeta value of the detector / Analyzer 10 does not necessarily need to be the result of a thermal conductivity measurement The scope of the invention includes any type of detector / measurement analyzer that produces signal levels (eg discrete zeta values) that may be correlated with the percentage of Saturation of the gas sample When it is desired to determine the amount of liquid PFC in the expired respiratory gas, the 56 flowmeter is used. The flow rate measurements are correlated with quantities in liquid volume associated with the zeta value measurement taken at the same time. These values, together with the liquid / vapor conversion factor * of equation 7, are then used to determine the total amount of loss of liquid PFC. An example of an experimental volume loss calculation is as follows: 57 Flow of gas in the diffuser TLV - 8 1 / rn? N% saturation (zeta) - 100% Temperature = 37 degrees Celsius Time of the course - 30 minutes u PFC volume loss - (8000 rnl / min) xp 1.447 rnl of PFOB / 100 rnl of air) x 100%] x Cl rnl of fluid / 86 mi of steam) x 30 rn. = 40.3 mi In this way, the loss in volume of PFC in 30 minutes is 40.) mi. The invention described above allows signifi- cantly improved control of liquid venting processes. An operator no longer has to guess whether to add PFC to the patient's lungs and in what quantity, to optimize the PFC-gas interaction and to replace vaporized and evaporated liquid PFC. The invention also describes simple and cost-effective techniques for adding a PFC recovery to total liquid ventilation systems and maximizing the efficiency of the recovery system. In addition, the invention describes how useful the saturation values of PFC are in a wide variety of other biomedical applications. The present invention can be applied in other specific forms without departing from the spirit or essential attributes thereof and, therefore, reference should be made to the appended claims, rather than to the foregoing description, as indicative of the scope of the invention.

Claims (2)

1. NOVELTY OF THE INVENTION CLAIMS 1. - A procedure for determining the amount of interaction in a mammalian lung between a respiratory fluid in the lung and a respiratory gas flowing in and out of a pulmonary pathway in communication with the lung, said procedure comprising the steps of : a) rn? constipate expired respiratory gas from the pulmonary route; b) passing the sampled gas through a measurement detector, the detector produces a discrete value representative of a gas property; c) comparing the discrete value with discrete values previously determined, represents ives of the respiratory gascompletely saturated with vapors of breathing liquid and of the respiratory gas saturated with the vapors of respirable liquid; and d) determining the amount of interaction from the comparison, whereby the discrete values close to the fully saturated discrete values indicate maximum interaction and discrete values close to the saturated discrete values indicate minimum interaction.
2. 2. A method according to claim 1, further characterized in that the gas is sampled from an endotracheal tube connected to one end of the pulmonary route and at the other end to a gas ventilator. 3.- A procedure in accordance with reiv indication 2, also characterized because the ost reluctant gas is returned to the endotracoal tube after sampling. 4. A method according to claim 7, further characterized in that the sampled gas is pumped through a closed circuit sample path that includes the measurement detector. 5. A method according to claim 1, further characterized in that the respiratory liquid is perfluorocarbon. 6. A method according to claim 1, further characterized in that the measurement detector is a thermal conductivity detector and the discrete value is representative of the thermal conductivity of the gas. 7. A procedure to determine the rate of volume loss of respirable fluid in the lung when the respiratory gas flows in and out of a pulmonary pathway in communication with the lung, said procedure comprising the steps of: a) measuring the instant ventilation, VM; b) Sample expired respiratory gas from the pulmonary route; c) passing the sampled gas through a measurement detector, the detector produces a discrete value representative of a gas property; d) correlating the discrete output value of the measurement detector with a percentage of vapor volume-respirable liquid in the gas; and e) calculate the rate of loss of breathable liquid volume expired from the equation: VM X (% by volume of vapor of respirable liquid in the gas) x CLV; where CLV is an iquid / vapor conversion factor 1 for the respirable liquid. 8. A method according to claim 7, further characterized in that the respiratory fluid is per 1 carbon dioxide. 9. A method according to claim 7, further characterized in that the measurement detector is a thermal conductivity detector and the discrete value is representative of the thermal conductivity of the gas. 10., - A procedure to control the amount of respirable fluid in the lung while the respiratory gas flows to and from the pulmonary pathway * in communication with the lung, this procedure comprises the steps of: a) measuring ventilation instant, VM; b) sample expired respiratory gas from the pulmonary route; c) passing the sampled gas through a measurement detector, the detector * produces a discrete value representative of a gas property; d) correlating the discrete output value of the measurement detector with a percentage by volume of vapor of breathing liquid in the gas; e) calculate the volume loss of respira- tory fluid expired from the equation: VM x (% in volume of vapor- of respirable liquid in the gas) x total ventilation time x CLV; where CLV is a liquid / vapor conversion factor for the respirable liquid; and f) adding breathing fluid to the lung from a reservoir of respirable fluid in fluid communication with the lung to replenish the lost volume. 11. A method according to claim 10, further characterized in that the breathable liquid is perfluorocarbon. 1. A method according to claim 10, further characterized in that the measurement detector is a thermal conductivity detector * and the discrete-value is representative of the thermal conductivity of the gas. 13. A procedure to determine and control the amount of interaction in a mammalian lung in a respiratory fluid in the lung and a respiratory gas that flows in and out of a pulmonary pathway in communication with the lung, said procedure comprises the steps of: a) rn? estrear * expired respiratory gas from the pulmonary route; b) passing the gas sampled through a measurement detector, the detector produces a discrete value representative of a gas property; c) compare the discrete value with a scale of discrete values previously determined, one end of the scale represents respiratory gas completely saturated with vapors of respirable liquid and the other end of the scale represents breathing gas saturated with vapors of respirable liquid; d) determine from the comparison the amount of interaction, whereby discrete values close to the fully saturated discrete value indicate maximum interaction and discrete values close to the unsaturated discrete value indicate minimal interaction; and e) perform at least one intervention function to increase * the amount of interaction if it decreases below a preset amount. 14. A method according to claim 13, further characterized in that the intervention function includes reublining the mammal, thereby relocating the lung. 15. A method according to claim 14, further characterized in that the mammal is located on a platform and the relocation includes the step of reorienting the platform. 16. A method according to claim 14, further characterized in that a reservoir of respiratory fluid is in fluid communication with the lung, and a second intervention function includes adding respiratory fluid from the reservoir to the lung if the fluid fails. Option to increase the amount of interaction to the preset amount. 17. A method according to claim 13, further characterized in that a reservoir of respirable liquid is in fluid communication with the lung, and the intervention function includes adding reepirabie liquid in the reservoir to the lung. 18. A method according to claim 13, further characterized in that the measurement detector is a thermal conductivity detector and the discrete value is representative of the thermal conductivity of the gas. 19. A procedure for monitoring and reducing * residual amounts of respirable fluid in a mammalian lung after changing the lung's ventilation from liquid respirabLe to gas lung ventilation; the respiratory gas flows in and out of a pulmonary pathway in communication with the lung, said procedure comprises the steps of: a) sampling expired respiratory gas from the pulmonary route; b) pass the sampled gas through a measuring detector, the detector produces a discrete * value representative of a gas property, c) compare the discrete-value with a scale of previously determined discrete values, one end of the scale represents respiratory gas completely saturated with vapors of respirable liquid and the other end of the scale represents respiratory gas unsaturated with vapors of respirable liquid; d) determine the interactionality from the comparison, the discrete values near the fully saturated discrete value indicate maximum interaction between the respirable fluid in the lung and the respiratory gas that flows in and out of the lung, and values discrete near the discrete unsaturated value indicate minimal interaction between them; e) calculate the rate of change of the interaction amount; and f) performing at least one intervention function to increase the amount of interaction and thereby exhaust more quickly the residual amount of respirable fluid, if the rate of change is below a pre-opened amount. 20. A method according to claim 19, further characterized in that the pulmonary route is connected to a gas fan, and the intervention function includes increasing the respiratory velocity of the ventilator. 21. A method according to claim 19, further characterized in that the pulmonary route is connected to a gas fan, and the intervention function includes increasing the inspiratory pressure of the ventilator. 22. A method according to claim 19, further characterized in that the measurement detector is a thermal conductivity detector and the discrete value is representative of the thermal conductivity of the gas. 23.- A procedure to monitor the operation of a breathable liquid vapor recovery system that recovers reepirable liquid from a gas stream within it, the procedure comprises the steps of: a) sampling gas at an output of the system of recovery; b) passing the sampled gas through a measurement detector, the detector produces a discrete value representative of a gas property; and c) compare the measured discrete value with a pre-established convenient discrete value indicating the proper operation of the recovery system, the discrete value A convenient preselected is within a range of previously determined discrete values, one extr-emo of the scale represents respiratory gas completely saturated with vapors of respirable liquid and the other end of the scale represents the respiratory gas plus saturation with vapors of respirabie liquid. 24. A method according to claim 23, further characterized in that the measurement detector is a thermal conductivity detector and the discrete value is representative of the thermal conductivity of the gas. 75.- A procedure to monitor and control the operation of a breathable liquid vapor recovery system that recovers the respirable liquid from a gas stream inside it, the system includes a condenser- to condense the vapors of respirable liquid and? n Tepnostat to control the temperature of the condenser; the method comprises the steps of: a) sampling gas at an outlet of the recovery system; b) passing the sampled gas through a measurement detector, the detector produces a discrete value representative of a gas property; c) compare the measured discrete value with a pre-established convenient discrete value indicating the proper operation of the recovery system, the preselected convenient discrete value is within a scale of previously determined discrete values, one end of the scale represents fully saturated respiratory gas with vapors of respirable liquid and the other extr-emo of the scale represents unsaturated breathing gas with re-liquid liquid vapors; and d) adjusting the set point of the condenser thermostat in response to a measured discrete value that is significantly different from the preset convenient value. 76. - A method according to claim 75, further characterized in that the recovery system receives the current < The gas from a carbon dioxide removal system having an oxygenator / di- ductor and a pump, the method also includes the step of e) adjusting the flow velocity of the pump in response to a measured discrete value * it is significantly different from the pre-selected convenient value. 27. A method according to claim 25, further characterized in that the measurement detector is a thermal conductivity detector and the discrete value is representative of the thermal conductivity of the gas. 28.- A procedure to quantify the evaporative loss rate of perfluoroc liquid rbono from a blood supply of a mammal through the respiratory system when the perfluorocarbon is used as a blood substitute, the procedure comprises the steps of: a) injecting perfluorocarbon in the bloodstream of a mammal; b) measure instantaneous ventilation, VM; c) Sample the expired respiratory gas from the pulmonary route; d) passing the sampled gas through a measurement detector, the detector produces a discrete value representative of a gas property; e) correlating the discrete output value of the detector-measurement with a percentage volume of perfluorocarbon vapor in the gas; f) calculate the speed of loss in volume of perfluorocarbon liquid expired from the equation: VM X (% by volume of vapor of breathing liquid in the gas) x CLV, where CLV is a conversion factor 1 For the perfluorocarbon liquid, the speed of loss in volume of expired luorocarbon μef represents the rate of evaporative loss through the respiratory system. 29. A method according to claim 28, further characterized in that the measurement detector is a thermal conductivity detector and the discrete value is representative of the thermal conductivity of the gas. 30. A method for quantifying the evaporative loss of perfluorocarbon liqui or a mammal by loss through transpiration through the skin, the method comprising the steps of: a) placing a collection device against an area of the skin of the mammal and collect-a sample of gas from it; b) pass the sampled gas through a measurement detector, the detector produces a discrete value representative of a property of the gas, the discrete value has a scale that at one end represents respiratory gas completely saturated with perfluorocarbon vapors and at the other end it represents an unsaturated respiratory gas with perfluorocarbon vapors; and c) correlating the discrete output value of the measurement detector with a discrete value indicative of the total loss by transpiration. 31. A method according to claim 30, further characterized in that the measurement detector is a thermal conductivity detector and the discrete value is representative of the thermal conductivity of the gas. 32.- A procedure that uses perfluorocarbon vapor to determine the residual functional capacity, FRC, of a mammalian lung, the procedure comprises the steps of: a) breathing from a container of known volume, Vi, and containing a known concentration , Ci, of perfluorocarbon vapor for a predetermined period; b) m? consign gas in the container after the predetermined period; c) passing the sampled gas through a measurement detector, the detector produces a discrete value representative of a gas property, the discrete heat has a scale at the extreme represents gas respi r * at opo completely saturated with perfluorocarbon vapors and at the other end represents unsaturated respiratory gas with perfluorocarbon vapors; d) correlating the discrete output value of the measurement detector up to a final concentration, Cf, of perfluorocarbon vapor in the container; and f) determining the functional residual opacity with the formula FRC = Vi [(Ci / Cf) -1]. 33. - A method according to claim 32, further characterized in that the measurement detector * is a thermal conductivity detector and the discrete value is representative of the thermal conductivity of the gas. 34.- A method to correct errors in a measurement of residual functional capacity made while a patient is subjected to partial ventilation of liquid with a respiratory liquid, the errors are caused by the presence of vapors of respirable liquid in the expired respiratory gas, the method comprises the steps of: a) measuring the residual functional capacity of a patient; b) sample expired respiratory gas from the patient's pulmonary route, the patient is in communication with the lung; c) passing the spent gas through a measuring detector, the detector produces a discrete value representative of a property of the gas, the discrete value has a scale that at one end represents respiratory gas completely saturated with vapors of respirable liquid and at the other end it represents respiratory gas that is saturated with vapors of respiratory fluid; d) calculate from said discrete value the amount of vapor- of respirable liquid in the sampled gas; and e) adjust the measurement of residual functional capacity with said quantity of vapor (respirable liquid). A method according to claim 34, further characterized in that the measurement detector is a thermal conductivity detector and the discrete value is representative of the thermal conductivity of the gas 36.- A system to determine the amount of interaction in a mammalian lung between a breathable liquid in the lung and a respiratory gas that flows in and out of a pulmonary pathway in communication with the lung. lung, the system comprises: a) a sampler adapted to sample expired gas; b)? n measurement detector adapted to receive the sampled gas, the detector produces a discrete value representative of a gas property: and c) a processor to compare the discrete value with previously determined discrete values, the processor determines the state of the liquid breathable inside the lungs based on the comparison. 37.- A system according to claim 36, further characterized in that the sampled gas is respiratory gas, the previously determined discrete values are representative of respiratory gas completely saturated with vapors of breathable liquid and respiratory gas unsaturated with vapors of respirable liquid, and the processor determines the amount of interaction from the comparison, discrete values close to the fully saturated discrete value indicate maximum interaction and discrete values close to the unsaturated discrete value indicate minimal interaction. 38.- A system according to claim 36, further characterized in that the system determines the rate of volume loss of respirable liquid in the lung, and the system also comprises means for measuring instantaneous ventilation, VM; The processor correlates the discrete output value of the measurement detector with a percentage volume of vapor of breathing liquid in the gas and calculates the rate of loss in breathable liquid volume expired from the equation: MX (% in vapor volume of Breathable liquid in the gas) x CL, where CLV is a factor (ie, conversion 11 qui do / vapor for the respiratory liquid 39, A system in accordance with the claim 36, further characterized in that the system controls the amount of respirable liquid in the lung; the system also comprises means for measuring instantaneous ventilation, V; The processor correlates the discrete output value of the measurement detector with a percentage by volume of vapor of breathing liquid in the gas and the processor calculates the loss in breathable liquid volume expired from the equation: VM X (% in volume of vapor * of respirable liquid in the gas) x total ventilation time x CL, where CLV is a liquid / vapor conversion factor for the respiratory liquid, and the processor controls the addition of respiratory fluid to the lung from? n Breathable fluid reservoir in fluid communication with the lung p >to replenish the lost volume. 40.- A compliance system according to claim 36, further characterized in that the discrete values determined previously define a scale, one end of the scale represents respiratory gas saturated completely with vapors of respirable liquid and the other end of the scale represents gas Respiratory saturated with vapors (He breathable liquid, the processor determines the amount of interaction from the comparison, the discrete values close to the discrete value completely saturated) Maximum interaction between the liquid rospirabie in the puLrnon and the respiratory gas that flows inward 41. A system according to claim 40, further characterized by the fact that the system ommites and reduces residual amounts of respirable liquid. mammalian lung after changing lung ventilation n with breathable fluid to gas lung ventilation; the processor calculates the rate of change of the interaction amount and increases the amount of interaction to deplete-more quickly the residual amount of respirable liquid if the rate of change is below a pre-set amount. 42. A system according to claim 36, further characterized in that the system includes a condenser for condensing the vapors of respiratory liquid and a thermostat to control the temperature of the condenser, the processor adjusts a fixing point of the condenser thermostat in response to a measured discrete value that is significantly different from the appropriate value is displayed. 43. A system according to claim 36, further characterized in that the system quantifies the rate of evaporative loss of respirable fluid from the blood supply of a mammal through the r-spiratope system, when the perfluorocarbon is used as a substitute. of blood; the system also comprises means for injecting perfluorocarbon into the bloodstream of a mammal; and means for measuring instantaneous ventilation, V; the processor correlates the discrete output value of the measurement detector with a volume percentage of perfluorocarbon vapor in the gas, and calculates the loss velocity in liquid volume of expired μerfluorocarbon from the equation: VM X (% in vapor volume of breathing liquid in the gas) x CLV, where CLV is a liquid / vapor conversion factor for the perfluorocarbon liquid, the rate of expired perfluorocarbon volume loss represents the rate of evaporative loss at through the respiratory system. 44. A system according to claim 36, further characterized in that the system quantifies the evaporative loss of liquid perfluorocarbon from a mammal by loss through transpiration through the skin; the sampler is a collection system close to an area of the skin of the mammal and is adapted to collect a gas sample (Jel itself) and the processor correlates the discrete value * of the measurement detector output with an indicative value-discrete 45. A system according to claim 36, further characterized in that the system corrects errors in a measurement of residual functional capacity made while a patient is subjected to partial ventilation of liquid with a respirable fluid, the errors being caused by the presence of respiratory liquid vapors in the expired respiratory gas, the system also comprises means to measure the residual functional capacity of a patient, the gas sampled is from a patient's pulmonary route, the is in communication with the lung, the processor calculates from the discrete-value the amount of vapor of respirable liquid in the gas m sampled, and adjusts the measurement of residual functional capacity based on the calculation. SUMMARY OF THE INVENTION The amount of respirable liquid removed from a mammal by volatilization in the lungs and / or perspiration in the skin is detected by measuring the saturation amount of the expiratopo gas with the vapors of respirable liquid; instantaneous saturation values are evaluated to determine the amount of interaction in the lungs between the respiratory liquid and the respiratory gas that flows in it, and to control * selected realization operations to maintain the maximum possible amount of interaction between them.; the expiration gas saturation level is also used to optimize operating parameters of a respiratory liquid recovery system from the expiratory gas, directly from the patient (24) or liquid fan gas (76); the expiratory gas saturation level is also used to perform studies of residual functional capacity and to correct errors in conventional measurements of residual functional capacity, performed while a patient is subjected to partial liquid ventilation; When respirable fluid is used as a substitute for blood, quantifying the loss of respirable fluid through volatilization and transpiration helps determine when to re-absorb the respirabie liquid into the bloodstream; the vapors of a breathable liquid form, perfluorocarbon, are used to determine the residual functional capacity of a mammalian lung, EA / ycl * apm * elt * blm P97 / 540F