Fertilization device for assisted reproduction in medicine

Abstract

A fertilization device (1) for an in vitro fertilization method, comprising a pneumatic actuator (2) and a needle holder (5) connected to the pneumatic actuator (2) by an air transport tube (4). In the fertilization device (1), the fertilization device comprises a temperature automatically regulated magazine (7) disposed between the needle holder (5) and the air transport tube (4). A plurality of tanks (8, 12) are provided in the magazine. The magazine (7) is configured to be movable, and each of the plurality of tanks (8, 12) selectively establishes a hydrodynamic connection to both the needle holder (5) and the air transport tube (4) simultaneously.

Description

Technical Field

[0001] (Cross - reference to related applications) This patent application claims the priority of the specification of Italian Patent Application No. 102022000009731 filed on May 11, 2022, and the entire disclosure thereof is incorporated herein by reference. The present invention relates to a fertilization device for implementing a method of Medically Assisted Procration (MAP).

Background Art

[0002] In MAP, it is assumed that the fertilization method uses intracytoplasmic sperm injection (ICSI) technology to inject sperm into an oocyte.

[0003] ICSI is a technology that emerged about 30 years ago and assumes that fertilization involves mechanically injecting sperm into an oocyte that has been removed from the ovary, that is, removing the cells of the cumulus and corona radiata and then injecting the sperm.

[0004] The ICSI technology has the advantage that by providing for the injection of sperm into the cytoplasm, it can also treat cases of oligoasthenoteratozoospermia, that is, semen with reduced concentration, motility, and morphology.

[0005] Furthermore, this technology ensures the activation of the oocyte because the ovarian cytoplasm is aspirated into a glass pipette that transports the sperm. In this way, the contact between the ovarian cytoplasm and the sperm, and thus the activation of the oocyte, is promoted.

[0006] Despite the above - mentioned advantages, the ICSI technology has the drawback that it still largely depends on the operator's ability regarding the oocyte fertilization time.

[0007] During the ICSI procedure, the oocytes are placed in an injection dish, in which microdrops of buffered culture medium covered with flowing paraffin oil preheated to a temperature of 37° are prepared. Under these conditions, the operator is expected to perform fertilization on each oocyte in a time range of one and a half to two minutes. Since the manual skills of the operator vary greatly, it can happen that the oocytes are fertilized for a longer time, thereby entailing the risk of thermal and oxidative stress that can affect embryo development. Furthermore, considering that usually six oocytes are fertilized at once (arranged in a 2×2 pattern in 3 microdrops), the time between the first and the last fertilized oocyte is 10 - 12 minutes. This is a dangerous time interval that can have an adverse effect on fertilization, blastomere (cell division), and blastocyst.

[0008] For 30 years, the device used to collect one sperm at a time and fertilize oocytes has not undergone any significant changes. In fact, despite technological improvements, the lack of standardization of results regarding fertilization still remains. Two important variables that affect the results of in vitro fertilization are the skills of the operator and the quality of the oocytes to be fertilized. There is a major obstacle to the quality of oocytes in medicine since nothing can be done about the limitations regarding genetic characteristics and biological age, but it is possible to intervene in the quality of the method from the perspective of technological progress.

[0009] According to the technology used so far, the operator has to collect sperm from a polyvinylpyrrolidone droplet using a micropipette and then move it within the droplet together with the oocyte and fertilize the first oocyte. The same steps have to be repeated as many times as the number of oocytes to be fertilized.

[0010] Cell thermal stress and free radical formation are directly proportional to the exposure time outside the incubator. In fact, the main cause of oxidative stress is oxygen, and thus, the exposure of oocytes to atmospheric oxygen induces a decrease in development at the morula and blastocyst stages. Various studies have demonstrated that these effects are irreversible and remain even if the oocytes are placed in the incubator at optimal oxygen concentration and temperature levels.

[0011] Gametes and embryos are natural sources of free radicals, but during manipulation, the risk of generating supra-physiological levels is increased by inducing a state of oxidative stress that can have a significant impact on in vitro fertilization.

[0012] In conclusion, it is clear from the above that long-term exposure to atmospheric oxygen induces an increase in oxidative stress, which in turn induces a decrease in fertilization rate and thus may impair pregnancy outcome.

[0013] Therefore, there is a need for a device that reduces the time that oocytes are exposed to atmospheric oxygen and at the same time reduces the dependence of the success of in vitro fertilization techniques on the skills of the operator.

[0014] The inventors of the present invention have realized an apparatus having technical features that meet the above needs. SUMMARY OF THE INVENTION

[0015] The subject of the present invention is a fertilization device for an in vitro fertilization method, the fertilization device comprising a pneumatic actuator and a needle holder connected to the pneumatic actuator by an air transport tube, wherein the fertilization device comprises a temperature automatically regulated magazine disposed between the needle holder and the air transport tube, a plurality of tanks are provided in the magazine, each of the plurality of tanks is configured to accommodate at least one sperm, the magazine is configured to be moved, and each of the plurality of tanks selectively establishes a hydrodynamic connection to both the needle holder and the air transport tube simultaneously.

[0016] Here, in the following, "hydrodynamic connection" means that a fluid flow path is formed between the needle, one of the tanks, and the air transport tube.

[0017] Preferably, each of the plurality of tanks is a tube having a capillary diameter in the range of 400 - 800 μm.

[0018] Preferably, the fertilization device comprises a support structure, the support structure accommodating the magazine and comprising a coupling duct designed to be connected to the needle holder and the air transport tube, the needle holder and the coupling duct being aligned with each other.

[0019] Preferably, the magazine is a drum suitable for rotating about its longitudinal axis of symmetry, a plurality of cylindrical holes being provided in the drum, the plurality of holes being arranged longitudinally around the longitudinal axis of symmetry, each of the plurality of holes being configured to define a respective trough, each of the plurality of holes being selectively aligned with the needle holder and the coupling duct and configured to establish a hydrodynamic connection to the needle holder and the coupling duct.

[0020] Preferably, the support structure comprises two parts hinged to each other to allow access to the magazine from the outside.

[0021] Preferably, the support structure comprises electric moving means configured to move the magazine.

[0022] Preferably, the fertilization device comprises a control system, the control system being configured to detect preset conditions of a pneumatic actuator and to be connected to at least one visual and / or acoustic signaling device.

[0023] Preferably, the fertilization device includes a display indicating the troughs involved in the in vitro fertilization procedure.

Brief Description of the Drawings

[0024] Hereinafter, embodiments will be disclosed for illustrative and non-limiting purposes with reference to the accompanying drawings.

Figure 1

Figure 2

Best Mode for Carrying Out the Invention

[0025] In FIG. 1, reference numeral 1 indicates the apparatus of the present invention according to a preferred embodiment as a whole.

[0026] The apparatus 1 includes a pneumatic actuator 2 and a support structure 3 connected to the pneumatic actuator 2 by an air transport tube 4. The support structure 3 includes a needle holder 5 and a coupling duct 6 that extends on the side opposite to the needle holder 5 and is configured to be connected to one end of the air transport tube 4. In particular, the needle holder 5 and the coupling duct 6 define respective passages that are aligned with each other.

[0027] The apparatus 1 includes a drum-shaped magazine 7 housed within the support structure 3, and this magazine is free to move about its longitudinal axis of symmetry X.

[0028] The magazine 3 is provided with a plurality of through holes 8 having an axis parallel to the axis X and symmetrically arranged about the axis X. Each of the plurality of through holes 8 defines a groove for accommodating at least one sperm to be injected into the interior of the oocyte during the in vitro fertilization operation. By rotating the magazine 7 about the axis X, each of the plurality of through holes 8 is selectively in an operating position and aligned with both the needle holder 5 and the coupling duct 6. The support structure 3 includes an encoder schematically shown and illustrated at 9, which engages a portion of the magazine 7 to cause its rotation about the axis X and selectively positions each of the through holes 8 in their operating positions. A display 10 connected to the encoder 9 is disposed within the support structure 3. The display 10 indicates which of the through holes 8 is in the operating position (aligned with the needle holder 5 and the coupling duct 6).

[0029] The support structure 3 is composed of a front part 3a and a rear part 3b which are hinged to each other along an axis Y orthogonal to the axis X. The rotation along the axis Y means that the support structure can be arranged in a closed configuration (Figure 1), where the housing of the magazine 7 is defined between the front part 3a and the rear part 3b, while it can be arranged in an open configuration (Figure 2), which means that access from the outside of the through-hole 8 is possible. The open configuration allows the insertion of a disposable gasket 11, which comprises a plurality of tubes 11 housed in respective through-holes 8 and defines the outer wall of a single tank in each through-hole 8. Each of the tubes 12 has a diameter in the range of 100 - 800 μm.

[0030] The micrometer dimensions ensure the permanence of the aspirated fluid within a single tube.

[0031] From the above, the structural and functional similarities between the support structure 3 and the drum gun will be understood by the reader.

[0032] The magazine 7 is connected to temperature regulating means schematically indicated at 13 and serves to maintain the whole magazine at about 37 °C.

[0033] The pneumatic actuator 2 comprises a macrometric knob 14 and a micrometric knob 15, which control the movement of a piston 16 sliding inside a cylinder 17 within the same pneumatic actuator 2 with different sensitivities. The movement of the piston 16 allows both the aspiration and injection of micro-samples, as will be explained below.

[0034] The pneumatic actuator 2 comprises a system for the position control of the piston 16 in order to inform the operator about the progress of the in vitro fertilization method. In particular, the control system is schematically represented by a transmitter chip indicated at 18. The transmitter chip 18 communicates with one or more visual signalers (lights) 19 housed in the support structure 3 and / or the pneumatic actuator 2. Alternatively, or in combination with the visual signaler, an acoustic signaler can also be provided for the device.

[0035] The fertilization device 1 is arranged on the main body of the pneumatic actuator, connected to the encoder 9, and further includes a button 20 for controlling its operation and thus the rotation of the magazine 7.

[0036] Hereinafter, an in vitro fertilization method using the fertilization device 1 according to the present invention will be described. The in vitro fertilization method essentially consists of two steps, namely (i) a step of continuously collecting sperm and (ii) a step of continuously fertilizing oocytes.

[0037] The preparation step of the fertilization device 1 provides, first, operating the temperature automatic control means 13 to maintain the magazine 7 at about 37°C. Subsequently, the support structure 3 is placed in its open configuration so that the disposable gasket 11 can be loaded into the magazine 7. At this point, the needle 21 is inserted into the needle holder 5. The needle 21 is inserted until it reaches each of the tubes 11 with which it is aligned. The needle 21 and the disposable gasket 11 are the only parts that come into contact with the human body and are therefore replaced in each new in vitro fertilization method.

[0038] Once the fertilization device 1 is prepared as described above, it becomes possible to carry out the step of continuous sperm collection. This step involves the fertilization device collecting sperm treated with traditional techniques, such as hyaluronic acid or polyvinylpyrrolidone. The suction by the fertilization device is carried out by suction controlled by appropriate rotation of knobs 14 and 15. During suction, the transmitter chip 18 detects when the piston 16 reaches a previously set position to ensure that a single sperm is placed by suction within each tube 12. The transmitter chip 18 activates the visual signaler 19 to indicate that the piston has reached the previously identified position and thus the sperm has been received in the trough aligned with the needle 21. At this point, the operator instructs, by means of button 20, the encoder 9 to effect a rotation about the axis X of the magazine 7 so as to bring about a new through-hole 8 and thus a new tube 12 aligned with the needle 21 and the coupling duct 6. The rotation of the magazine 7 is displayed on the indicator 11, showing the number corresponding to the through-hole 8 in the operating position. When this condition is reached, the above-described operation is repeated, and thus a second sperm is received in a second trough. In particular, each time the magazine 7 rotates and a new tube 12 comes into the operating position, at least one of the visual signalers 18 indicates that the same operating position has been brought about and that the new tube 12 is ready to receive each sperm. At the same time, the indicator reports the number corresponding to the through-hole 8 in which the tube 12 ready to be loaded with a new sperm is located.

[0039] According to a further embodiment, the transmitter chip 18 is directly connected to the encoder 9 such that when the transmitter chip 18 itself detects the previously set position of the piston 16, the magazine 7 rotates automatically.

[0040] The above operation is repeated until all the tubes 12 of the magazine 7 are filled.

[0041] Once the step (i) of continuous sperm collection is completed, move on to the step (ii) of continuous fertilization of the oocytes.

[0042] Oocytes are collected from the incubator and then placed into the microdrops of the injection dish according to the prior art.

[0043] At this time, the fertilization device 1 starts the fertilization of the first oocyte by using the thrust of the pneumatic actuator 2 due to the rotation of the knobs 14, 15 by the operator. When the fertilization of the first oocyte is completed, the operator rotates the magazine 7 around the axis X by the button 20, bringing a new through-hole 8 and thus a new tube 12 aligned with the needle 21 and the connecting duct 6. At this new operating position of the fertilization device 1, the second oocyte is fertilized. Similarly, what has been reported above for the collection step (i) is that each time the magazine 7 rotates to bring a new tube 11 to the operating position, at least one of the visual signalers 18 notifies that the same operating position has been reached, and thus a new tube 12 "loaded" with sperm is arranged to proceed with the fertilization of a new oocyte. At the same time, the number assigned to the through-hole 9 at the operating position is displayed on the display 11.

[0044] These operations are repeated until all the sperm present in the magazine 7 are injected into their respective oocytes.

[0045] As can be immediately understood from the above description, the fertilization device according to the present invention enables both significantly reducing the implementation time and automating the operation, thereby reducing the influence of the individual operator's ability on the overall success of the medically assisted reproduction method.

[0046] The use of the device according to the present invention enables collecting oocytes only for the time required for fertilization. Thereby, the risk of oxidative stress can be significantly reduced. For example, with the device of the present invention, it is possible to perform the fertilization of a single oocyte in a time not exceeding 1 minute, and thus it is calculated that it is possible to fertilize up to 6 oocytes in less than 5 minutes instead of 10 or 12 minutes of the prior art.

Claims

1. A fertilization device (1) for an in vitro fertilization method, comprising: a pneumatic actuator (2); and a needle holder (5) connected to the pneumatic actuator (2) by an air transport tube (4). In the fertilization device (1), the fertilization device (1) comprises a temperature automatically controlled magazine (7) disposed between the needle holder (5) and the air transport tube (4), the magazine being provided with a plurality of tanks (8, 12), each of the plurality of tanks (8, 12) being configured to accommodate at least one sperm, the magazine (7) being configured to move, and each one of the plurality of tanks (8, 12) being selectively configured to establish a hydrodynamic connection simultaneously with both the needle holder (5) and the air transport tube (4). Fertilization device (1).

2. The fertilization device (1) according to claim 1, wherein each of the plurality of tanks (8, 12) is a tube (8, 12) having a capillary diameter in the range of 100 to 800 μm.

3. The fertilization device (1) according to claim 1, further comprising a support structure (3), the support structure (3) housing the magazine (7) and having a coupling duct (6) configured to be connected to the needle holder (5) and the air transport tube (4), wherein the needle holder (5) and the coupling duct (6) are aligned with each other. Fertilization device (1).

4. The magazine (7) is a drum suitable for rotating about its longitudinal axis of symmetry (X), the drum being provided with a plurality of cylindrical holes, the plurality of holes being arranged longitudinally around the longitudinal axis of symmetry (X) and provided to define respective tanks, each of the plurality of holes being selectively aligned with the needle holder (5) and the coupling duct (6) and configured to establish a hydrodynamic connection with the needle holder (5) and the coupling duct (6). Fertilization device (1) according to claim 3.

5. The fertilization device (1) according to claim 3, wherein the support structure (3) comprises two parts (3a, 3b) hinged to each other to allow access to the magazine (7) from the outside.

6. The fertilization device (1) according to claim 1, wherein the support structure (3) comprises electric moving means (9) configured to move the magazine (7).

7. The fertilization device (1) comprises a control system (18), the control system (18) detecting preset conditions of the pneumatic actuator (2) and being connected to at least one visual and / or acoustic signalizer (19), the fertilization device (1) according to claim 1.

8. The fertilization device (1) comprises a display (10), the display (10) notifying the tank related to the in vitro fertilization method, the fertilization device (1) according to claim 1.

Images