Device and method for regional homogenization of transthoracic-pulmonary pressure

Abstract

The invention relates to a device (10, 20) for the regional homogenization of transthoracic-pulmonary pressure, the device comprising: - a plurality of bladders (11, 26, 27, 28, 32, 33, 34), configured to at least partially surround the thorax of a predetermined primate (40), the plurality comprising at least one underinflated bladder, underinflated meaning at atmospheric pressure in the absence of any force exerted on an outer surface of the bladder; - for at least one underinflated bladder (11) of the plurality of bladders, a means (17) for measuring an internal pressure representative of the pressure resulting from the weight of the primate on the underinflated bladder; and - a means (18) for feedback-controlling the internal pressure of at least one bladder of the plurality of bladders using at least one measurement of the internal pressure of the underinflated bladder representative of the pressure resulting from the weight of the primate.

Description

[0001] DESCRIPTION OF THE DEVICE AND METHOD FOR REGIONAL HOMOGENIZATION OF THE

[0002] TRANS-THORACO-PULMONARY PRESSURE

[0003] TECHNICAL FIELD OF THE INVENTION

[0004] The present invention relates to a device and a method for homogenizing transthoracopulmonary pressure. It is particularly applicable to the field of artificial ventilation in the context of the treatment of acute respiratory failure or general anesthesia for surgery.

[0005] STATE OF THE ART

[0006] The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise stated, it should not be assumed that any of the approaches described in this section constitutes prior art simply because of its inclusion in this section.

[0007] The loss of muscle tone induced by deep sedation, combined with maintaining the patient in a supine position, contributes to the development of regional heterogeneity in pulmonary aeration, specifically including complete loss of aeration (atelectasis) of the dorsal lung regions. Modern artificial ventilation techniques, based on the non-physiological application of supra-atmospheric pressure to the entire respiratory system via an orotracheal intubation tube, are unable to adapt to such regional specificities.Thus, when applied indiscriminately to the entire lung volume, this pressure causes ventilator-induced lung injury (VILI), secondary to (1) alveolar overdistension of hyperaerated regions, predominantly in the ventral lobes, and (2) cyclic re-aeration, with each inspiration, of the aforementioned areas of atelectasis. The harm associated with VILI, and in particular with alveolar overdistension, is well-characterized biomechanically and clinically. This results in increased mortality among intensive care patients with acute respiratory distress syndrome (ARDS) and an increase in pulmonary complications following general anesthesia for major surgery. A validated method for preventing VILI involves mobilizing sedated and ventilated patients in the prone position.By redistributing the mechanical stresses applied by the chest wall to the lung parenchyma, the prone position remarkably prevents ventral alveolar overdistension and ultimately reduces ARDS mortality. However, its implementation can lead to complications, justifying limited use over time and the need for significant human and logistical resources.

[0008] Another method involves placing a weight, such as a sandbag or a bag of liquid, on the patient's chest. However, this method is localized. It does not take regional differences into account and only slightly reduces the aforementioned risks.

[0009] Document WO2019 / 048774 describes an anteroposterior thoracic restraint device comprising restraints designed to encircle a patient's rib cage, a compressible fluid bag intended to be held against the patient's sternum by said restraints, and reversible bilateral tightening means, arranged on either side of the fluid bag and capable of reversibly tightening the restraints around the patient's rib cage. However, this device, limited to anteroposterior thoracic restraint, does not allow for homogeneous circumferential compression. Furthermore, this device is not adaptable, region by region, and does not take into account the patient's position, particularly during care.

[0010] We know of European patent EP 3 997 974, US patent application US 2023 / 226 293, international application PCT WO 2023 / 177 793 and US patent application US 2022 / 192 913 which disclose prior art devices.

[0011] SUMMARY OF THE INVENTION

[0012] The present invention aims to remedy all or part of these drawbacks.

[0013] In general, the device of the invention is a vest that provides homogeneous constriction (circumferential compression) around the patient's thorax, stable over time. More specifically, it is a thoracic constriction vest with compressed air pockets designed to equalize the mechanical stresses exerted by the chest wall on the lungs and to homogenize regional pulmonary biomechanical conditions in sedated patients on mechanical ventilation. These features aim to reduce mortality associated with acute respiratory distress and prevent pulmonary complications after general anesthesia.

[0014] To this end, according to a first aspect, the present invention relates to a device for regional homogenization of transthoracopulmonary pressure, which comprises:

[0015] - a plurality of bladders, configured to at least partially surround the thorax of a predetermined primate, said plurality comprising at least one under-inflated bladder, under-inflated meaning at atmospheric pressure in the absence of force exerted on an external surface of said bladder,

[0016] - for at least one underinflated bladder, a means of measuring an internal pressure representative of the pressure induced by the primate's weight on said bladder,

[0017] - a means of controlling the internal pressure of at least one bladder of the plurality of bladders to at least one measurement of internal pressure of said under-inflated bladder representative of the pressure due to the weight of the primate.

[0018] Thanks to these arrangements, the trans-thoraco-pulmonary pressure exerted all around the thorax will be a function of the pressure exerted by the weight of the primate in the under-inflated bladder.

[0019] It is worth recalling here that an underinflated bladder is one whose internal pressure is equal to atmospheric pressure in the absence of any force exerted on its external surface. In other words, the bladder's outer layer is not taut when no force is applied to its external surface, thus preventing surface tension on this layer from increasing the bladder's internal pressure.

[0020] In optional embodiments, the plurality of bladders includes an underinflated so-called crushed bladder configured to be placed opposite the face of the primate's thorax positioned against a support, and at least one measuring means being configured to measure the internal pressure of said crushed bladder.

[0021] Thanks to these arrangements, the underinflated bladder corresponds to the bladder space between the primate and the support on which it rests. The primate can lie on its back, stomach, or side while the device is in operation.

[0022] In optional embodiments, the plurality of bladders includes primary bladders, the control means being configured to control the internal pressure of at least one of said primary bladders, and at least one secondary bladder, configured to be interposed between at least one primary bladder and the thorax of the primate. Through these arrangements, the secondary bladders distribute the pressure exerted by the primary bladders onto the skin of the primate and prevent this pressure from exceeding the pressure between these salient points at anatomical prominences (for example, over bones), thus allowing for spatial homogenization of the pressure exerted on the body surface.

[0023] In optional embodiments, at least one primary bladder is configured to receive a first fluid in a first state and in which at least one secondary bladder is configured to receive a second fluid in a second state, different from the first state.

[0024] In some embodiments, the first fluid is air and the second fluid is an aqueous solution, or in which the first fluid is an aqueous solution and the second fluid is air.

[0025] Thanks to each of these optional arrangements, an incompressible fluid can distribute the pressure exerted by a compressible fluid or, conversely, a compressible fluid can distribute the pressure exerted by an incompressible fluid.

[0026] In optional embodiments, the first fluid is compressed air and the second fluid is an incompressible aqueous solution.

[0027] Thanks to each of these measures, a leak of one of the fluids presents no danger to the primate or the environment.

[0028] In optional embodiments, the device of the invention further comprises a compressed air pressure regulator supplying the first fluid.

[0029] Thanks to these provisions, the device that is the subject of the invention can easily be implemented in a hospital or veterinary clinic equipped with a pressurized air circuit.

[0030] In optional embodiments, the device of the invention comprises a plurality of means for measuring the internal pressure of a plurality of bladders, the control means being configured to control the internal pressure of at least one bladder to the maximum pressure measured by said plurality of pressure measuring means.

[0031] Thanks to these arrangements, a change in the primate's position that would alter the pressure in a bladder equipped with a pressure sensor would be compensated for by the change in pressure in another bladder equipped with a pressure sensor. In optional embodiments, the device of the invention further comprises a support for at least one bladder made of a flexible, inextensible material.

[0032] In optional embodiments, the device of the invention comprises a dorsal bladder support configured to be positioned on the dorsal face of the primate's thorax, made of flexible inextensible material, a ventral bladder support configured to be positioned on the ventral and lateral faces of the primate's thorax, made of flexible inextensible material, and clamping means between the dorsal support and the ventral support, configured so that the supports surround the bladders and the thorax of the primate.

[0033] Thanks to these provisions, the device that is the subject of the invention can take the form of a vest or harness that can be easily put in place on the thorax of the primate.

[0034] According to a second aspect, the present invention relates to a method for regulating pressure in a plurality of bladders, which comprises:

[0035] - a step of positioning a plurality of bladders, at least one of them being under-inflated, under-inflated meaning at atmospheric pressure in the absence of force exerted on an external surface of said bladder, at the beginning of the process,

[0036] - for at least one underinflated bladder out of the plurality of bladders, a step of measuring the internal pressure of said bladder under the effect of an external force, and

[0037] - a step of controlling the internal pressure of at least one bladder of the plurality of bladders to at least one measurement of internal pressure of an under-inflated bladder subjected to an external force.

[0038] The advantages, purposes and particular characteristics of this process being similar to those of the device which is the subject of the invention, they are not recalled here.

[0039] BRIEF DESCRIPTION OF THE FIGURES

[0040] Other advantages, purposes and particular features of the invention will become apparent from the following non-limiting description of at least one particular embodiment of the device and method of the present invention, with reference to the accompanying drawings, in which:

[0041] Figure 1 schematically represents an internal view of a dorsal portion of a particular embodiment of the constriction device that is the subject of the invention.

[0042] Figure 2 schematically represents an internal view of a ventral part of the constriction device illustrated in [Fig. 1]. Figure 3 schematically represents an external view of the ventral part of the constriction device illustrated in [Fig. 2].

[0043] Figure 4 schematically represents a section AA referenced in [Fig. 3] of the ventral part of the constriction device illustrated in figures 2 and 3,

[0044] Figure 5 schematically represents a section of the thorax of a patient lying on their back and fitted with the device illustrated in Figures 1 to 4.

[0045] Figure 6 represents, in the form of a flowchart, the steps of a particular embodiment of the process that is the subject of the invention,

[0046] Figure 7 schematically represents an external view of the ventral part of a variant of the constriction device illustrated in [Fig. 2], and

[0047] Figure 8 schematically represents a section BB referenced in [Fig. 7] of the ventral part of the variant of the device.

[0048] DESCRIPTION OF IMPLEMENTATION METHODS

[0049] The present description is given by way of non-limiting attribution, each feature of an embodiment being able to be advantageously combined with any other feature of any other embodiment.

[0050] It should be noted from the outset that the figures are not to scale.

[0051] As can be understood from this description, various inventive concepts can be implemented by one or more of the methods or devices described below, several examples of which are provided herein. The actions or steps performed in implementing the method or device can be ordered in any appropriate manner. Consequently, it is possible to construct embodiments in which the actions or steps are performed in a different order than illustrated, which may include performing certain actions simultaneously, even if they are presented as sequential actions in the illustrated embodiments.

[0052] The expression "and / or," as used in this document, should be understood as meaning "either or both" of the elements thus joined, that is, elements that are present conjunctively in some cases and disjunctively in others. Multiple elements listed with "and / or" should be interpreted in the same way, that is, "one or more" of the elements thus joined. Other elements may also be present, besides those specifically identified by the "and / or" clause, whether or not they are related to those specifically identified elements.Thus, by way of non-limiting example, a reference to "A and / or B", when used in conjunction with an open language such as "including", may refer, in one embodiment, to A only (possibly including elements other than B); in another embodiment, to B only (possibly including elements other than A); in yet another embodiment, to A and B (possibly including other elements); etc.

[0053] As used here in the description, "or" should be understood inclusively.

[0054] As used in this description, the expression "at least one," when referring to a list of one or more items, should be understood as meaning at least one item chosen from one or more items in the list of items, but not necessarily including at least one of each item specifically listed in the list of items and not excluding any combination of items in the list of items. This definition also allows for the optional presence of items other than those specifically identified in the list of items to which the expression "at least one" refers, whether or not they are related to those specifically identified items.Thus, by way of non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B", or, equivalently, "at least one of A and / or B") may refer, in one embodiment, to at least one, possibly including more than one, A, without B present (and possibly including elements other than B); in another embodiment, to at least one, possibly including more than one, B, without A present (and possibly including elements other than A); in yet another embodiment, to at least one, possibly including more than one, A, and at least one, possibly including more than one, B (and possibly including other elements); etc.

[0055] In the description below, all transitional expressions such as "comprising," "including," "carrying," "having," "containing," "implying," "holding," "composed of," and others, should be understood as open-ended, meaning including but not limited to. Only the transitional expressions "consisting of" and "consisting essentially of" should be understood as closed or semi-closed transitional expressions, respectively. In the description below, "dorsal" refers to a portion of the device intended to be applied to the dorsal surface of the thorax, and possibly the lateral surfaces of the thorax, of a patient, and "ventral" refers to a portion of the device intended to be applied to the ventral surface of the thorax, and possibly the lateral surfaces of the thorax, of that patient.

[0056] In the description, an "internal" side of the device is turned towards the patient once the device is worn by the patient, and an "external" side is turned outwards.

[0057] The description does not fully describe the dimensions of the various components. However, a person with technical expertise can determine these dimensions to adapt the device to the rib cage anatomy of a predetermined patient, for example, an average European man as described in the literature. Naturally, the same device adapts to a range of anatomies around that of the predetermined patient, so that one, two, or three devices with different dimensions can meet the care needs of virtually an entire population. The following description refers to the use of the constriction device on a human patient positioned supine on a resuscitation bed or operating table. However, the present invention is not limited to this type of patient but extends to any predetermined patient in the order of primates.

[0058] Figure 1, not to scale, shows a schematic internal view of a dorsal portion 10 of a particular embodiment of the constriction device of the invention. This dorsal portion 10 comprises a dorsal bladder 11 supported by a non-extensible dorsal support 12, which may be flexible or rigid. For example, the dorsal support 12 is made of a fabric such as that used for manufacturing straps. The dorsal support 12 has, laterally, rings 13 for retaining straps 23 described opposite a ventral portion 20 of the device in Figures 2 and 3. These rings 13 and these straps

[0059] 23 allow the dorsal 10 and ventral 20 parts of the device to surround the patient's thorax 40 (see [Fig. 5]). The dorsal support 12 also has shoulder straps 15 with rings 14 to retain straps 24 described opposite the ventral part 20 of the device in Figures 2 and 3. The rings 13 and 14 and the straps 23 and

[0060] 24 constitute means for tightening a harness that positions the device on the patient's thorax 40. The dorsal bladder 11 is connected, by a tube 16, to a dorsal pressure sensor 17 integrated into a measurement and control unit 18. To ensure that the pressure measurement in the dorsal bladder 11 is representative only of the pressure present at the dorsal body surface (and not of the pressure of inflation of this bladder), this bladder 11 is under-inflated, that is, its internal pressure is equal to atmospheric pressure, down to a volume that avoids the folds of its surface.

[0061] The following definitions are recalled:

[0062] - transpulmonary pressure = alveolar pressure - pleural pressure,

[0063] - transthoracic pressure = pleural pressure - atmospheric pressure, and

[0064] - transthoracopulmonary pressure (or respiratory system pressure) = alveolar pressure - body surface pressure.

[0065] It is noted that the pressure on the body surface of a supine patient, for the portion of the thorax resting on the support, is the sum of atmospheric pressure and the pressure due to the patient's weight and the inclination of the support on which the patient is positioned. The pressure measured by pressure sensor 17 is therefore representative of the pressure present at the level of the body surface area resting on the support, induced by the patient's weight and the inclination of the support.

[0066] Figure 2, not to scale, shows a schematic internal view of the ventral portion 20 of the constriction device. This ventral portion 20 includes at least one ventral secondary bladder 26 supported by a flexible, inextensible ventral support 22. In the embodiment shown in Figure 2, this ventral portion 20 also includes a left ventral secondary bladder 27 and a right ventral secondary bladder 28. As shown opposite Figure 1, the ventral support 22 carries the lateral straps 23 and the shoulder straps 24. The lateral straps 23 and shoulder straps 24 are, for example, made of hook-and-loop fastener, also known as Velcro®. The dorsal support 12 and the ventral support 22, together with the tightening means 13, 14, 23, and 24, form an inextensible vest.

[0067] Figure 3, not to scale, shows an external schematic view of the ventral portion 20 of the constriction device. In addition to the elements already described opposite Figure 2, the ventral portion 20 includes, on its external side, at least one central primary bladder 32. In the embodiment shown in Figure 3, this ventral portion 20 also includes a left ventral primary bladder 33 and a right ventral primary bladder 34. In this embodiment, the internal volumes of the primary bladders 32, 33, and 34 are connected by channels 39. One of the primary bladders (here, the central bladder 32) is equipped with a connector 36 linked to a pressurized fluid inlet tube 35.In the embodiment shown, the pressurized fluid is compressed air supplied by a compressed air circuit 37 (also called "wall air" in hospital settings), via a pressure regulator 38 whose output pressure is controlled by the measuring and control unit 18 shown in [Fig. 1].

[0068] Generally, at least one primary bladder is configured to receive a first fluid in a first state, and at least one secondary bladder is configured to receive a second fluid in a second state, different from the first state. Preferably, the first fluid is air and the second fluid is an aqueous solution. Alternatively, the first fluid is an aqueous solution and the second fluid is air. In the preferred embodiment illustrated in Figures 1 to 5, the first fluid is compressed air and the second fluid is an aqueous solution, for example, physiological saline.

[0069] Section “AA” shown in [Fig. 4] contains previously described elements of the ventral portion 20 of the constriction device. It can be seen that, from its outer face (at the top of [Fig. 4]) to its inner face (at the bottom), the ventral portion 20 comprises the inextensible ventral support 22, the primary bladders 32, 33, and 34, and then the secondary bladders 26, 27, and 28. The connector for the pressurized fluid inlet tube 35 is located on the outer face of the ventral portion 20 of the device. In some variations, this connector for the primary bladder 32 is located on a lateral face, for example, the lower face of the bladder 32 or a face facing another bladder. Typically, each primary bladder has a thickness of approximately three centimeters under pressure.

[0070] The section of the thorax of a patient 40 lying on their back and fitted with the constriction device described in Figures 1 to 4, shown in [Fig. 5], contains elements already described in those figures. The section of thorax 40 shown includes the right lung 41, the left lung 42, the heart 43, and the vertebral column 44. The primary bladders 32, 33, and 34, controlled by the device 18, pressurize the body surface in relation to the different regions of the lungs 41 and 42, according to the pressure measured by the sensor 17 within the under-inflated, compressed dorsal bladder 11. The secondary bladders 26, 27, and 28 ensure good spatial distribution of this pressure on the patient's skin. The pressure regulator 38 is connected, at its inlet, to a compressed air intake means 37, typically a pipe connected to a compressed air circuit of a hospital establishment.The pressure regulator 38 has a valve and is connected, at the output to the compressed air inlet tube 35 in each primary bladder 32, 33 and 34, via the primary bladder 32.

[0071] The outlet pressure of the pressure regulator 38 is controlled by the housing 18 to link the internal pressure of each primary bladder 32, 33, and 34 to the pressure measurement taken by the pressure sensor 17 within the dorsally compressed underinflated bladder 11. Thus, even in the event of a slight leak or if the device straps were to loosen, the pressure in the primary bladders 32, 33, and 34 remains linked to the pressure measured in the dorsally compressed underinflated bladder 11. This linkage is dynamic. This linkage can be the application, in the primary bladders 32, 33, and 34, of the pressure measured in the dorsally compressed underinflated bladder 11. The linkage function can also include:

[0072] - a configurable value of pressure difference between the pressure applied to the primary bladders 32, 33 and 34 and the pressure measurement in the under-inflated, crushed dorsal bladder 11,

[0073] - a configurable value of a multiplicative factor between the pressure applied to the primary bladders 32, 33 and 34 and the pressure measurement in the under-inflated, crushed dorsal bladder 11,

[0074] - a non-linear function between the pressure applied to the primary bladders 32, 33 and 34 and the pressure measurement in the under-inflated, crushed dorsal bladder 11 or

[0075] - a combination of these control functions.

[0076] The parameter values ​​can be set by a caregiver or be set by construction, in the memory of box 18.

[0077] As can be understood from the preceding description, the device shown in Figures 1 to 5, in its first embodiment, takes the form of a vest that provides homogeneous and stable constriction of the patient's thorax 40's body surface over time. This vest is in two parts: a dorsal part 10 and a ventral part 20, allowing it to be put on an unconscious patient. The material of the bladder support 22 is flexible, allowing it to bend around the patient's thorax 40, but inextensible. The inextensible nature of the support 22 allows the internal pressure of the primary bladders to be transmitted to the skin surface of the patient's thorax throughout the respiratory cycle.These supports 12 and 22 are connected by means of fastening (self-gripping straps 23, self-gripping shoulder straps 24, rings 13 and 14 for these straps) which allow the two supports 12 and 22 of the vest to be secured around the bladders 11, 26, 27, 28, 32, 33 and 34, which themselves surround the thorax of the patient 40.

[0078] Bladders are made of flexible materials, such as thermoplastic polyurethane (PU) for primary bladders and polyvinyl chloride (PVC), polypropylene, silicone, or rubber for secondary bladders. The flexible material of the bladders allows for even pressure distribution around the patient's chest.40 If the material of a bladder in contact with the patient's skin were too rigid, folds (i.e., "breaks") could occur, preventing the bladder from adhering to the patient's skin.

[0079] The primary bladders 32, 33, and 34 contain compressed air at the pressure controlled by the control unit 18, this pressure being transferred to the patient's chest 40. The secondary bladders 11, 26, 27, and 28 contain a liquid, typically an aqueous solution, for example, saline. These secondary bladders distribute the pressure exerted by the primary bladders onto the user's skin and prevent this pressure from exceeding the pressure between these points at protruding anatomical areas (for example, over bones).

[0080] A pressure sensor 17 determines the pressure measured in the under-inflated, compressed dorsal bladder 11. This sensor 17 determines the pressure to be applied to the primary bladders 32, 33, and 34, and therefore to the entire periphery of the patient's thorax 40. Typically, the patient is placed lying on the under-inflated dorsal bladder 11, and the pressure within this bladder 11 is measured after it has been compressed by the patient's weight. The control unit 18 then controls the pressure in the primary bladders 32, 33, and 34 to dynamically obtain the same internal pressure in each, thus simulating the patient's body weight on their lungs in a uniform manner.

[0081] In the embodiments shown above, the under-inflated, compressed bladder is a dorsal bladder. However, it is clear that the under-inflated, compressed bladder can be a lateral or ventral bladder depending on the primate's position and which side of its thorax it rests on. [Fig. 6] shows, in the form of a flowchart, the steps of a particular embodiment of the pressure regulation method in a plurality of bladders that are the subject of the invention.

[0082] This method 50 comprises, firstly, a step 51 of positioning a plurality of bladders, at least one of them being under-inflated, at atmospheric pressure in the absence of force exerted on an external surface of said bladder, at the beginning of the method. In the case of the device illustrated in figures 1 to 5, this involves positioning the dorsal part 10 behind the patient's back at the level of their thorax, its inner surface being in contact with the patient's skin or a light garment, then positioning the ventral part 20 on the ventral face of the thorax and on its lateral faces (flanks), then attaching the dorsal part 10 and ventral part 20, by passing the straps 23 and 24 through the rings 13 and 14 and attaching them to themselves.Alternatively, the dorsal 10 and ventral 20 parts are first connected by passing the straps 24 through the rings 14 and fastening them back on themselves. Then, these two parts are put on like a harness before the straps 23 are passed through the rings 13 and fastened back on themselves. These two procedures are particularly applicable to the case of an unconscious or sedated patient.

[0083] The method 50 then includes, for at least one bladder, a step 52 of measuring the internal pressure of said under-inflated bladder under the effect of an external force. For example, the external force corresponds to a gravitational compression force on said bladder due to the weight and position (torso tilt) of the patient. In the case of the device shown in Figures 1 to 5, this measurement is typically performed by a fluid pressure sensor 17 within the under-inflated, compressed bladder 11. This pressure is representative of the force applied to the under-inflated, compressed bladder 11 by a portion of the patient's weight. This pressure is also representative of (and practically equal to) the pressure exerted by the support on which the patient rests (generally a mattress) on the dorsal surface of the patient's thorax.

[0084] The method 50 then includes a step 53 of controlling the pressure of at least one bladder from the plurality of bladders according to at least one pressure measurement. In the case of using the device shown in Figures 1 to 5, the housing 18 establishes, for example, the pressure setpoint value sent to the pressure regulator 38 as equal to the pressure value measured by the pressure sensor 17. In other words, the measuring and control housing 18 controls the pressure in the primary ventral bladders 26, 27 and 28, to the pressure measured by the sensor 17 of the pressure in the under-inflated, crushed bladder 11.

[0085] As can be understood from the preceding description, the device of the invention is a non-stretchable vest, adapted to the thoracic morphology of patients placed in the supine position. This device generates circumferential compression (or constriction) of the thorax. Compressed air from hospital systems, partially depressurized and injected into the device's primary bladders, is used as the driving force to maintain continuous and stable constriction over time. The mechanical constraint thus exerted prevents alveolar overdistension associated with mechanical ventilation, reproducing the beneficial biomechanical effects of the prone position in a safer and more resource-efficient manner.The device thus ensures homogeneous circumferential compression in space (not anteroposterior) and individualized according to the measurement of a physiological reference value (maximum pressure on the skin surface of the face of the chest constrained by the weight and position of the patient); and uses compressed air allowing fine regulation and stability of compression levels over time.

[0086] Variants of the embodiment described in Figures 1 to 6

[0087] In embodiments (not shown), the device of the invention comprises a harness of a known type.

[0088] In some embodiments (not shown), the device does not include a secondary ventral bladder, the primary ventral bladders being in direct contact with the patient's skin or with light clothing worn by the patient.

[0089] In some embodiments (not shown), the primary bladders contain a fluid in a liquid state and the secondary bladders contain a fluid in a gaseous state.

[0090] In some embodiments (not shown), at least one primary bladder covers, at least partially, at least two secondary bladders. In other embodiments (not shown), at least one secondary bladder is covered, at least partially, by two primary bladders.

[0091] In some embodiments (not shown), the dorsal part of the device includes a primary bladder, in addition to the under-inflated, compressed bladder 11 (which thus becomes secondary). In this case, the pressure measurement can be performed on either of these bladders.

[0092] In some embodiments (not shown), the device of the invention comprises a plurality of means for measuring the internal pressure of a plurality of bladders. The control means then regulates the internal pressure of at least one bladder to the maximum pressure measured by a plurality of pressure measurement means. For example, a central dorsal bladder is positioned under the patient's spine, and two lateral dorsal bladders are positioned on either side of this central dorsal bladder. The pressure measurement in these three dorsal bladders makes it possible to determine the patient's change in position, for example, during sleep, an examination, or treatment. The maximum value of the measurements thus obtained represents the maximum pressure on the patient's thorax and is used to regulate the pressure in the primary bladders.

[0093] In some embodiments (not shown), the dorsal bladder is initially under-inflated and is inflated when the patient's position changes.

[0094] In some embodiments, the compression vest also allows local modulation of compression, for example differentiated between the right lung 41 and left lung 42.

[0095] Figure 7, not to scale, shows an external schematic view of the ventral portion 60 of a second embodiment of the constriction device. The dorsal portion 10 of this device is that of the first embodiment. The main difference between the ventral portion 60 and the ventral portion 20 is that the internal volumes of the primary bladders 32, 33, and 34 are not connected. Each primary bladder 32, 33, and 34 is equipped with a connector 36 for pressurized fluid inlet tubes 35, 66, and 67, respectively.

[0096] Section "BB," shown in [Fig. 8], contains previously described elements of the ventral portion 60 of the constriction device. It can be seen that, from its outer to its inner surface, the ventral portion 60 comprises the inextensible ventral support 22, the primary bladders 32, 33, and 34, and then the secondary bladders 26, 27, and 28. The connectors 36 for the pressurized fluid inlet tubes 35, 66, and 67 are located on the outer surface of the ventral portion 60 of the device. In some variations, each connector for a primary bladder is located on a lateral surface, for example, the underside of the bladder or a surface facing another bladder. Typically, each primary bladder has a thickness of approximately three centimeters under pressure.

[0097] Three pressure regulators 38, 61, and 62 are connected at their inlets to a compressed air intake means 37, typically a pipe connected to a compressed air circuit in a hospital. The pressure regulators 38, 61, and 62 each have a valve and are connected at their outlets to the compressed air inlet tubes 35, 66, and 67, respectively, for supplying compressed air to the primary bladders 32, 33, and 34, respectively.

[0098] The outlet pressure of each pressure regulator 38, 61, and 62 is controlled by the housing 18 to link the internal pressure of each primary bladder 32, 33, and 34 to the pressure measurement taken by the pressure sensor 17 on the under-inflated, compressed bladder 11. Thus, even in the event of a slight leak or if the device straps were to loosen, the pressure in the primary bladders 32, 33, and 34 remains linked to the pressure value measured in the under-inflated, compressed bladder 11. Note that the control functions applied by the housing 18 may differ for the primary bladders 32, 33, and 34, for example, according to choices made by a caregiver.

Claims

DEMANDS 1. Device (10, 20) for regional homogenization of transthoraco-pulmonary pressure, characterized in that it comprises: - a plurality of bladders (11, 26, 27, 28, 32, 33, 34), configured to at least partially surround the thorax of a predetermined primate (40), said plurality comprising at least one under-inflated bladder, under-inflated meaning at atmospheric pressure in the absence of force exerted on an external surface of said bladder, - for at least one underinflated bladder (11) of said plurality of bladders, a means for measuring (17) an internal pressure representative of the pressure induced by the weight of the primate on said underinflated bladder and - a means of controlling (18) the internal pressure of at least one bladder of the plurality of bladders to at least one measurement of internal pressure of said under-inflated bladder representative of the pressure induced by the weight of the primate.

2. Device (10, 20) according to claim 1, wherein the plurality of bladders comprises an under-inflated bladder said to be "crushed" (11) configured to be placed opposite the face of the thorax of the primate (40) positioned against a support, and at least one measuring means (17) being configured to measure the internal pressure of said under-inflated crushed bladder.

3. Device (10, 20) according to any one of claims 1 or 2, wherein the plurality of bladders (11, 26, 27, 28, 32, 33, 34) comprises primary bladders (32, 33, 34), the control means being configured to control the internal pressure of at least one said primary bladder, and at least one secondary bladder (26, 27, 28), configured to be interposed between at least one primary bladder and the thorax of the primate.

4. Device (10, 20) according to claim 3, wherein at least one primary bladder (32, 33, 34) is configured to receive a first fluid in a first state and wherein at least one secondary bladder (26, 27, 28) is configured to receive a second fluid in a second state, different from the first state.

5. Device (10, 20) according to claim 4, wherein the first fluid is air and the second fluid is an aqueous solution, or wherein the first fluid is an aqueous solution and the second fluid is air.

6. Device (10, 20) according to claim 5, wherein the first fluid is compressed air and the second fluid is an incompressible aqueous solution.

7. Device (10, 20) according to claim 6, which further comprises a compressed air pressure regulator (38) supplying the first fluid.

8. Device (10, 20) according to any one of claims 1 to 7, comprising a plurality of internal pressure measurement means (17) of a plurality of bladders, the control means (18) being configured to control the internal pressure of at least one bladder to the maximum pressure measured by said plurality of pressure measurement means.

9. Device (10, 20) according to any one of claims 1 to 8, further comprising a support (12, 22) for at least one bladder (11, 26, 27, 28, 32, 33, 34) made of flexible, inextensible material.

10. Device (10, 20) according to claim 9, comprising a dorsal support (12) for a bladder (11) configured to be positioned on a dorsal face of the primate's thorax, made of a flexible, inextensible material, a ventral support (22) for bladders (26, 27, 28, 32, 33, 34) configured to be positioned on the ventral and lateral faces of the primate's thorax (40), made of a flexible, inextensible material, and clamping means (13, 14, 23, 24) between the dorsal support and the ventral support, configured so that the supports surround the bladders and the thorax of the primate.

11. Method (50) for regulating pressure in a plurality of bladders (11, 26, 27, 28, 32, 33, 34), characterized in that it comprises: - a step (51) of positioning a plurality of bladders, at least one of them being under-inflated, under-inflated meaning at atmospheric pressure in absence of force exerted on an external surface of said bladder, at the beginning of the process; - for at least one underinflated bladder out of the plurality of bladders, a step (52) of measuring an internal pressure of said bladder under the effect of an external force, and - a step (53) of controlling the internal pressure of at least one bladder of the plurality of bladders to at least one pressure measurement.

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