WO2012017417A2

WO2012017417A2 - A thermoregulation device for thermoregulation of an organic fluid in medical apparatuses

Info

Publication number: WO2012017417A2
Application number: PCT/IB2011/053508
Authority: WO
Inventors: Daniele Galavotti; Corrado Bellini
Original assignee: Rand S.R.L.
Priority date: 2010-08-05
Filing date: 2011-08-05
Publication date: 2012-02-09
Also published as: WO2012017417A3; IT1401332B1; ITMO20100231A1

Abstract

The thermoregulator device for thermoregulating an organic fluid in medical apparatus comprises a thermoregulator unit (20); a passage unit (1 ) for said organic fluid, arranged for being thermoregulated by said thermoregulator unit (20); said thermoregulator unit (20) comprises a thermoregulation seat (21 ), and said passage unit (1 ) can be removably coupled to said thermoregulation seat (21 ) in a thermoregulation configuration.

Description

THERMOREGULATOR DEVICE FOR THERMORAGULATION OF AN ORGANIC FLUID IN MEDICAL APPARATUS

Field of application

The invention regards a thermoregulator device for fluids, in particular in medical apparatuses, which has a substantially planar body that defines, at its interior, a space for the passage of corporeal fluids. Such passage is along a path configured in a manner so as to generate a tortuous and sufficiently turbulent fluid-dynamic motion in the fluids, such to exchange heat exclusively via contact with an exchange member that defines one side of the container body, eliminating the use of a thermo-conditioned fluid.

State of the Art

Disposable heat exchangers have been known for some time in the medical device field. They are used for thermally conditioning an organic fluid, typically the blood which flows in extracorporeal circuits during cardiopulmonary bypass treatments, or generally in all therapies wherein a considerable amount of patient blood during the execution of these treatments must be controlled by circulatory assistance systems, e.g. in order to compensate for the loss of heat due to the difference between the temperature of the patient, normally 37°C, and the ambient temperature, which is normally around 20 °C.

During the execution of treatments in which considerable blood volumes and flows are treated, which additionally require medium-long treatment times, it is possible that undesired hypothermic conditions are induced in the patient; alternatively, it might be necessary to condition the temperature of the patient, intentionally bringing it to a controlled hypothermic level as a function of the treatment to be administered, in order to subsequently bring the patient back to normal thermal conditions.

This requires using devices mounted along the circuits which allow precise control of the blood temperature in the patient.

The prior art comprises heat exchangers which use a heated or cooled fluid for the thermal conditioning, according to treatment requirements.

In practice, a blood flow is made to flow in an exchanger, very often connected to an oxygenator device. The exchanger is in contact with a bundle of ducts which have impermeable perimeter walls, inside of which the heated or cooled fluid (normally water) is made to flow.

The contact with these ducts determines the thermal conditioning of the blood, both for heating and cooling it.

Known from patent US 6,045,752 is a "Blood oxygenator with waterless heat exchanger" which comprises a so-called "non-disposable" heater/cooler, which has a thermally-controlled surface that can be intimately coupled with a heat-conducting surface of a disposable blood heat exchanger associated with an oxygenator.

The blood flows in a narrow path in contact with the heat-conducting surface, such that the entire blood volume assumes the temperature of the heat- conducting surface.

This state of the art has a series of drawbacks.

A first drawback, typical of heat exchangers that use thermoregulated fluids for heating or cooling blood, consists of the fact that the indispensable use of thermoregulated fluid must be provided.

In known thermoregulator devices, this implies construction difficulties, since suitable passage ducts of this thermoregulated fluid must be provided, along with specific chambers for heat exchange with the blood that must be thermoregulated; in the end, there are overall size problems for these thermoregulator devices.

A second drawback is that accidents can occur, due to which the barriers are damaged that are provided for separating the ducts in which the thermoregulated fluid flows from the exchange chamber in which the blood flows, or the ducts themselves are damaged. Such damage causes an undesired mixing, dangerous for the safety of the patient since the biological integrity of the blood to be re-sent would be irreparably compromised by the mixing with the thermoregulated fluid.

A further drawback, still typical of the exchangers which employ a thermoregulated fluid, is that specific external tubes are necessary for feeding and recirculating the fluid, and these tubes, added to those in which the blood flows to/from the patient, can overall hinder the efforts of the doctors and auxiliary personnel, as they become tangled up with the equipment.

Another drawback is that the machines for the extracorporeal circulation which normally use these exchanger devices, e.g. those which are used for heart operations or for rapid aid treatments, known as heart-lung machines, are hard to transport due to their dependence on the presence of a thermoregulator fluid source. The requires transporting patients from the site of the accident to hospitals where such machines are always available and stably connected to the thermoregulator fluid feed sources: this causes a loss of precious time before being able to start treatments in the attempt to save the life of the patient.

A further drawback typical of the oxygenator that does not require the use of a thermo-regulated fluid as described in US 6,045,752 is that it is necessary, in order to obtain a satisfactory and substantially uniform heat exchange, to arrange wide exchange surfaces and a substantially laminar exchange path between these which comprises two walls facing each other, flat or even curved, in a manner so as to maintain the distance between them substantially constant. One of such walls belongs to a non-disposable heater/cooler and is therefore designed to be hit by the blood of many patients during its use.

In addition, since in order to have an effective heat exchange according to the patent, the distance between the two surfaces that define the path must be very limited, on the order of 1 -2 millimeters and, simultaneously, the blood flow must be as slow as possible, it is possible that between the surfaces which form the paths there are zones where the blood tends to slow its flow, until it stagnates, progressively forming accumulations and coagulations that create undesired obstacles; on one hand, such obstacles limit the width of the exchange surfaces, and on the other hand they consequently lower the overall performance of the exchanger, which requires maintenance and cleaning operations in order to restore good functioning. Presentation of the invention

One object of the invention is to improve the state of the prior art.

Still another object of the invention is to obtain a thermoregulator device for fluids in medical apparatuses which allows regulating the temperature of a fluid in a medical apparatus without using an additional thermoregulator fluid. Still a further object of the invention is to obtain a thermoregulator device for fluids in medical apparatuses that prevents the formation of accumulations and which makes the temperature regulation of the fluid to be thermoregulated uniform.

A further object of the invention is to obtain a thermoregulator device for fluids in medical apparatuses which allows freeing the machines which use it from fixed connections for feeding and discharging a thermoregulator fluid, making them independent and transportable also for use in emergency operations outside hospitals, directly where the patient to be aided is situated.

According to one aspect of the invention, a thermoregulator device for fluids in medical apparatuses is provided, in accordance with claim 1 .

The invention therefore allows to :

- obtain a uniform thermoregulation of fluids in medical apparatuses;

- prevent the formation of obstacles during the thermoregulation steps, that reduce the extension of the exchange surfaces;

- free the medical equipment that uses the thermoregulator device from fixed connections, in a manner such that it can be transported wherever an emergency operation is required;

- make the constructive structure and the assembly of the thermoregulator device substantially simplified with respect to the state of the prior art, and therefore considerably more economical; - prevent any possible contamination of the treated fluid, being able to use completely disposable components;

- be coupled to other disposable devices, used in extracorporeal circulation, in a simple and quick manner, so as to form a single body with such other devices.

Brief description of the drawings

Further characteristics and advantages of the invention will be clearer in light of the detailed description of several preferred but not exclusive embodiments of a thermoregulator device for fluids in medical apparatuses according to the invention, illustrated as a non-limiting example in the drawing set, in which:

FIG. 1 is a perspective and exploded view of a passage unit for an organic fluid, which is part of a thermoregulator device for thermoregulating an organic fluid in medical apparatuses, according to the invention;

FIG. 2 is a front view of the passage unit of Figure 1 , without a heat exchange surface in order to be able to observe the interior;

FIG. 3 is a perspective and very schematic view of a thermoregulator unit to which the passage unit of Figure 1 is coupled;

FIG. 4 is a perspective view of the thermoregulator unit of Figure 3, in which thermoregulator means were removed, in order to be able to more easily observe the thermoregulation position of the passage unit;

FIG. 5 shows a step of coupling or uncoupling between a passage unit and a thermoregulator unit;

FIG. 6 schematically shows a passage unit coupled to an oxygenator for oxygenating an organic fluid;

FIG. 7 is a perspective view of the thermoregulator device according to the invention of Fig. 5, from a different observation point;

FIG. 8 is an exploded and perspective view of the members which constitute a thermoregulation device, with which the thermoregulator device Fig. 7 is equipped. Detailed description of a preferred embodiment

With reference to the mentioned figures, with 1 a passage unit for an organic fluid is indicated in its entirety, intended to be coupled with a thermoregulator unit 20, forming a thermoregulator device for thermoregulating an organic fluid in medical apparatuses, according to the invention.

The passage unit 1 comprises a box-like body 2 with highly flattened form, inside of which a thermoregulation chamber 3 is defined in which a thermoregulation path is identified for the organic fluid that must be thermoregulated, indicated with the arrows "P1 " in Figure 2.

Typically, the path "P" starts from an entry port 4, which in the specific case is equipped with a derived opening 4' for executing the "priming" steps of the unit 1 and of the entire extracorporeal circuit connected to the latter, and finishes at an exit port 5. Both ports are obtained in the body 2 and place the thermoregulation chamber 3 in communication with the body 2 exterior

As can be seen in Figures 1 and 2, inside the thermoregulation chamber 3, projecting members 6 are arranged that are designed to divert the blood flows during the passage. Such members 6 are arranged according to a pre- established geometric arrangement, creating a dense network composed of a plurality of passage channels 9 that intersect each other and divert the organic fluid in all the zones of the thermoregulation chamber 3, in order to better distribute it in contact with an inner face of a heat exchange surface 10. When the passage unit 1 is assembled, such surface 10 forms a closure wall of the thermoregulation chamber 3.

With reference to Figure 1 , it is observed that the heat exchange surface 10 is intended to be abutted against a sealing gasket 1 1 which is engageable on a rib 12 obtained in the body 2, and which is perimetrically projected from the thermoregulation chamber 3.

In turn, the heat exchange surface 10 is fixed to the body 2 by means of a frame 13 arranged for being fit under pressure in a groove 1 1 a that is perimetrically obtained between the thermoregulation chamber 3 exterior and the perimeter edge 2a of the body 2, in which the frame 13 can also be glued, hermetically closing the thermoregulation chamber 3 from the outside. The heat exchange surface 10 is obtained with every known material that has high thermal conductivity properties, such as a steel plate; nevertheless, the man skilled in the art is capable of providing other materials for obtaining the heat exchange surface 10 which have the same high thermal conductivity characteristic.

As seen in Figures 1 and 2, in the thermoregulation chamber 3, a separating diaphragm 14 is provided which divides the chamber into two separate sections, i.e. an entry section "S1 " and a subsequent exit section "S2".

The separating diaphragm or ribbing 14 is integral or is subsequently made integral with the rib 12 and forms a single body therewith.

A corresponding segment 13a is designed to be inserted on the separating diaphragm or ribbing 14, such segment 13a preferably continuously derived from the gasket 1 1 .

In the body 2, a third discharge port 16 is also obtained, which is connected with the thermoregulation chamber 3 and which is intended to evacuate from such chamber possible air bubbles present in the organic fluid to be thermoregulated. Such bubbles are collected in a space 16a, in order to prevent that they are sent to the patient. In figures 1 , 3, 4 and 5, a connection of "luer" type is obtained, i.e. which has standardized conicity, while in figures 2, 6, 7 and 8, a version is illustrated obtained with a protected opening, with membrane member only permeable to gases and mounted at the base of the opening.

As seen in the Figures, the body 2 also has a projecting rib 17, which is outwardly directed and arranged in order to function as a connection for coupling with an oxygenator 18, as seen in Figure 6, in a manner so as to form an oxygenation and thermoregulation group with the latter that is substantially a single piece, with reduced size with respect to the prior art.

The body 2 is also equipped with flexible connection members 19 that can be coupled to the thermoregulator unit 20, or uncoupled, as described below, part of the thermoregulator device according to the invention.

The thermoregulator unit 20 comprises a hollow seat 21 , inside of which the passage unit 1 is intended to be precisely inserted, as is visible in Figures 3 and 4, in a thermoregulation configuration.

At one wall of the hollow seat 21 , an autonomous thermoregulator group 22 is mounted (see Figure 3) which uses Peltier cells, which transmit heat or cold to the passage unit 1 via contact with the exchange surface 10 of the latter when it is inserted in the hollow seat 21 , in which it is retained with the engagement between the connection members 19 and a corresponding edge or tooth projecting from the hollow seat 21 (such edge or tooth provided for such purpose).

With reference to Figure 8, it is noted in detail that the thermoregulator unit 20 comprises a ventilator group 55, which in an assembled configuration is associated with a box-like body 56 through which air flows of thermal conditioning flow.

In turn, the box-like body 56 is in contact with a lateral face of a plurality of modular fin units 57, which in Figure 3 are indicated with 22 overall and which facilitate the heat exchange.

The box-like body 56 has an opposite face that is maintained in contact with thermo-electric members 58, typically comprising a plurality of Peltier cells 59.

The Peltier 59 cells are intended to be placed in contact, on the opposite side with respect to the box-like body 56, with a face of a heat/cold transfer plate 80 that is directed towards the cells, while the opposite face of this transfer plate 80 is intended to be placed in contact with the heat exchange surface 10 of the passage unit 1 in which, according to the preceding description, the organic fluid flows.

As seen in Figure 8, the hollow seat 21 is obtained in a frame 60 whose sides are respectively constituted by an open wall 60a, provided to the left with respect to the observer in order to allow the contact between the heat exchange surface 10 and the transfer plate 80, and by a box-like member 61 which has a thrust face 62 activated via a presence sensor that identifies the presence of the passage unit 1 in the hollow seat 21 . By means of the actuation of a manual and/or automatic command, such face 62 pushes on the corresponding face of the body 2 of the unit 1 when the latter is inserted inside the hollow seat 21 , maintaining the exchange surface 10 perfectly in contact with the heat/cold transfer plate 80.

The functioning of the thermoregulator device for thermoregulating an organic fluid in medical apparatuses is the following:

the fluid to be thermoregulated is drained from a patient "PT" and, through a first extracorporeal circuit section schematically and summarily indicated with 30 in Figure 6 and a pump 31 , commanded by a suitable motor, the fluid reaches the entry port 4 of the passage unit 1 , which is previously inserted in the hollow seat 21 of the thermoregulator unit 20, in a thermoregulation configuration.

The fluid enters into the thermoregulation chamber 3 and is spread completely therein, diverted by the projecting members 8 and following the channels 9 defined between these; it is diffused over all of the inner surfaces of the thermoregulation chamber 3.

The liquid follows the thermoregulation path by first flowing into the entry section "S1 " and subsequently passing through the exit section "S2", obliged by the diaphragm 14 to complete a substantially helical trajectory.

Shortly before the start of the flow of the fluid in the thermoregulation chamber 3, the thermoregulator group 22 is activated which has the plate 80 in direct contact with the exchange surface 10 of the passage unit 1 .

In this manner, the thermoregulator group 22 transmits heat or cold to the exchange surface 10 and from this, the heat or cold is transmitted, once again via contact, to the organic fluid which flows in the thermoregulation chamber 3.

When the organic fluid has completed the thermoregulation path, it exits from the thermoregulation chamber 3 already thermoregulated, through the exit port 5. From the latter, in case of coupling for example with an oxygenator 18, it enters directly into such oxygenator in order to be subjected to an oxygenation treatment.

When the oxygenation treatment has been completed, the blood is re-sent to the patient "PT" through a second return section 31 of the extracorporeal circuit.

As already stated, the thermoregulation configuration of the thermoregulator device according to the invention is obtained by inserting the passage unit 1 in the relative seat 21 provided in the thermoregulator unit 20.

The seat 21 is also obtained in slit form, and one side wall thereof is substantially constituted by the thermoregulator group 22, such that when the passage unit 1 is inserted, the heat exchange surface 10 results in contact with the thermoregulator group 22, receiving its heating or cooling according to the treatments to be executed on the patient "PT"; the surface 10 is thrust against such group 22 by the box-like member 61 associated with the frame 60.

When the treatment is completed, the entire passage unit 1 , i.e. the disposable heat exchanger, is extracted from the hollow seat 21 and disposed of together with the tubes, including the devices which make up the extracorporeal circuit of connection with the patient "PT".

It must be underlined that the functional independence of the thermoregulator unit 20 with regard to fixed sources of thermoregulation fluids makes medical assistance possible to patients who have urgent need, directly at the site where they are situated.

It has been observed that the invention attains the pre-established objects. The invention as conceived is susceptible to modifications and variants, all part of the inventive concept.

Moreover, all details can be substituted with other technically equivalent elements.

In the practical actuation of the invention, any material can be employed and any shape and size utilized, as needed, without departing from the protective scope of the following claims.

Claims

1 . A thermoregulator device for thermoregulating an organic fluid in medical apparatuses, comprising:

- a thermoregulator unit (20);

- a passage unit (1 ) for said organic fluid, arranged for being thermoregulated by said thermoregulation unit,

characterized in that said thermoregulator unit (20) comprises a thermoregulation seat (21 ) and that said passage unit (1 ) can be removably coupled to said thermoregulation seat (21 ) in a thermoregulation configuration.

2. A device according to claim 1 , wherein said thermoregulator unit (20) comprises a thermoregulator group (22, 22a) placed at a perimeter wall of said thermoregulation seat (21 ) and configured in a manner so as to thermoregulate said passage unit (1 ) via contact.

3. A device according to claim 1 , wherein said passage unit comprises:

- a body (2) inside which a thermoregulation chamber (3) is defined; - a port of entry (4) into said thermoregulation chamber (3) for said fluid to be thermoregulated and an exit port (5) for the thermoregulated fluid;

- a thermoregulation path (P) defined in said thermoregulation chamber (3) that defines a flow direction of said fluid between said entry port (4) and said exit port (5); and

- at least one surface (10) for heat exchange with said fluid to be thermoregulated, intended to be positioned in close contact with said thermoregulator group (22, 22a).

4. A device according to preceding claims, wherein inside said thermoregulation chamber (3), flow diverting means (6) are provided for said organic fluid, such means placed between said heat exchange surface (10) and a wall of said thermoregulation chamber (3) opposite said heat exchange surface (10), in a manner so as to distribute said flow along said thermoregulation path (P) in a substantially uniform manner.

5. A device according to claim 4, wherein said flow diverting means comprise a plurality of members (6) projecting from said opposite wall and arranged according to a geometrical distribution.

6. A device according to claim 5, wherein said plurality of projecting members comprises projecting members (6) distributed according to pre- established alignments, such to create a network of crossed channels (9) for the passage of said organic fluid along said thermoregulation path (P).

7. A device according to claim 3, wherein said body comprises a box-like body (2) that has flattened shape and defines a bottom wall, corresponding lateral walls and a closure wall parallel to said bottom wall, in which said heat exchange surface (10) is defined.

8. A device according to claim 3, wherein said thermoregulation path (P) comprises a first section (S1 ) for the entry of said organic fluid and a second section (S2) for the exit and placed as a continuation of said first section (S1 ), said first and second sections (S1 , S2) being separated from each other by separating diaphragm means (14).

9. A device according to claim 8, wherein said separating diaphragm means comprise a gasket segment (14) which is engaged on a corresponding projecting ribbing or rib segment (12) that is projectingly extended from said bottom wall towards the inside of said thermoregulation chamber (3), and that derives from a gasket (1 1 ) which perimetrically and continuously circumscribes said thermoregulation chamber (3).

10. A device according to any one of claims 3 and 7, wherein said heat exchange surface (10) coincides with said closure wall.

1 1 . A device according to any one of the preceding claims, wherein perimeter sealing means (1 1 ) are interposed between said heat exchange surface (10) and said lateral walls.

12. A device according to any one of the preceding claims, wherein said heat exchange surface (10) is associated with said box-like body (2) by joining means (13).

13. A device according to any one of the preceding claims, wherein a third discharge port (16), designed to discharge air from said thermoregulation chamber (3), is obtained in said body (2).

14. A device according to claims 1 and 3, wherein said body (2) comprises means (19) for fastening to said thermoregulation seat (21 ).

15. A device according to any one of the preceding claims, wherein said body (2) comprises means (17) for coupling to an oxygenator device (18), in a manner so as to form a substantially single body with the latter.

16. A device according to any one of the preceding claims, wherein said entry and exit ports (4, 5) are equipped with connection means configured in a manner so as to be sealingly and automatically coupled to corresponding connection means of apparatuses and/or modular members of an extracorporeal circuit.