Intra-uterine probe

Abstract

The invention deals with the crucial issue of obtaining reliable measurement of the fetus's physiological values during labour. For this, the inventors has found that maintaining a good position of the probe during measurement is very important and has developed a specific contact surface for the probe with a principal portion surrounded by two lateral wings. This drastically improves the quality of the measurement, resulting in a better prevention of hypoxia.

Description

[0001] INTRA-UTERINE PROBE

[0002] The present invention concerns an intra-uterine probe.

[0003] During the labor period, the infant makes the critical transition from its dependence on maternal and placental support, oxidative, nutritional, and endocrinological, and establishes independent life. The difficulty of this transition is indicated by mortality risks that are higher than any occurring until old age and by risks for damage to organ systems, most notably the brain that can be lifelong. During the labor period, the fetus has risk of severe hypoxia and metabolic acidosis. Oxygen is the most vital substrate necessary for mitochondrial respiration and is not stored in the body. Interruption of oxygen supply to cells can result in irreversible brain damage. Cerebral palsy due to intrapartum anoxia is one of the most deleterious consequences of labor.

[0004] There is therefore a need for an intra-uterine probe adapted to monitor one or several physical values with a very close proximity to the fetus.

[0005] To this end, the specification describes an Intra-uterine probe adapted to be held by a fetus, the intra-uterine probe comprising

[0006] - a body defining an interior volume, the body having a contact surface, adapted to be in contact with the head of the fetus,

[0007] - at least one sensor in the interior volume, the contact surface having a principal portion surrounded by two lateral wings.

[0008] The design of such probe meets the constraints imposed by its context of use, and notably optimize its passive retention in the uterine cavity.

[0009] In order to facilitate its insertion and installation, the body of the probe was elongated / rectangular in shape.

[0010] However, its width / thickness ratio presented the risk of rotation of the probe on itself during movement of the fetal head in the uterine cavity. In order to improve adhesion, the idea was to increase the contact surface without impacting the size during insertion. Inspired by the animal world, the wings of the Mobula or better known as the "manta ray" have been reproduced.

[0011] The extension of the probe in the form of “wings” increases the contact surface which makes it possible to collect more pressure from the uterine wall which transforms into a greater force on the contact surface and thus increases the friction between the probe and the head of the fetus.

[0012] The width of the "expanded" probe corresponding to its extent makes it more difficult for the probe to rotate on itself during rotational movements of the fetal head. This also enables to avoid slipping during contractions by increasing the contact surface. According to further aspects of the intra-uterine probe, which are advantageous but not compulsory, the intra-uterine probe might incorporate one or several of the following features, taken in any technically admissible combination:

[0013] - the principal portion is rectangular.

[0014] - the two lateral wings are symmetrical with relation to the principal portion.

[0015] - for each lateral wing, the ratio between a width of the lateral wing and a width of the principal portion is comprised between 70% and 100%.

[0016] - for each lateral wing, the ratio between a minimum length and a maximum length is comprised between 40% and 60%.

[0017] - for each lateral wing, the maximum length is equal to the length of the principal portion.

[0018] - each lateral wing has a trapeze shape.

[0019] - the trapeze shape comprises two parallel sides and lateral sides, the ratio between the dimensions of the lateral sides of the trapeze shape being comprised between 85% and 95%.

[0020] - the intra-uterine probe comprises an electroencephalography sensor and a nearinfrared spectroscopy sensor, the electroencephalography sensor and the nearinfrared spectroscopy sensor being in the interior volume.

[0021] - he at least one sensor is a fibered component.

[0022] - the intra-uterine probe comprises a holding portion, the holding portion being in contact with the contact surface and holding fibers. the holding portion is linked to the principal portion and has a same width.

[0023] - the length of the holding portion and the principal portion is comprised between 20 cm and 30 cm.

[0024] - the width of the principal portion is comprised between 1 .5 cm and 2.0 cm.

[0025] - the sum of the widths of the lateral wings and the width of the principal portion is comprised between 3.0 cm and 5.0 cm.

[0026] - each lateral wing has a minimal thickness and the principal portion has a maximal thickness, the minimal thickness being strictly inferior to the maximal thickness.

[0027] - the contact surface comprises at least one transitory portion located between the lateral wing and the principal portion, the transitory portion featuring a variable progressive thickness from the minimal thickness to the maximal thickness.

[0028] - each lateral wing, the ratio between the minimal thickness of the lateral wing and the maximal thickness of the principal portion is comprised between 1 / 6 and 1 / 3.

[0029] - each lateral wing is elastically deformable. The invention will be better understood on the basis of the following description which is given in correspondence with the annexed figures and as an illustrative example, without restricting the object of the invention. In the annexed figures:

[0030] - figure 1 shows schematically two figures of an intra-uterine probe, the left figure being a figure of the intra-uterine probe seen from the fetus head when the intrauterine probe is in position and the right figure being a figure of the intra-uterine probe seen from the uterine wall when the intra-uterine probe is in position,

[0031] - figure 2 shows a schematic view of the intra-uterine probe of figure 1 in position,

[0032] - figure 3 shows a schematic corresponding representation of a part of the intra-uterine probe,

[0033] - figure 4 shows a schematic sectional view of a part of the intra-uterine probe, and

[0034] - figure 5 shows other embodiments of the surface contact of the intra-uterine probe.

[0035] An intra-uterine probe 10 is represented on figure 1.

[0036] The intra-uterine probe 10 adapted to be held by a fetus 14.

[0037] More precisely, as can be seen on figure 2, the intra-uterine probe 10 is held by the head 16 of the fetus 14.

[0038] The intra-uterine probe 10 comprises a body 12 and at least one sensor 18.

[0039] The body 12 is defining an interior volume in which the at least one sensor 18 is located.

[0040] The body 12 has a head 20 and a holding portion 22.

[0041] The head 20 comprises a contact surface 24 adapted to be in contact with the head 20 of the fetus 14.

[0042] More specifically, the contact surface 24 has a specific shape adapted to be inserted when the cervix is dilated and adapted to be held by the fetus 14.

[0043] The contact surface 24 has a principal portion 26 surrounded by two lateral wings 28 and 30.

[0044] According to the example of figure 1 , the principal portion 26 is rectangular.

[0045] Figure 3 is a schematic representation of the principal portion 26 by corresponding polygons.

[0046] This is an approximation in so far as the angles are not acute but slightly curved. Indeed, the rounded shape of the wings eliminates the sharp edges of the probe 10. In this figure, the principal portion 26 is a rectangle named ABCD, in a plane parallel to an axis X and an axis Y as illustrated on figure 1 .

[0047] The length of the principal portion 26 is L and the width of the principal portion 26 is I.

[0048] The length of an element is defined as the dimension of said element along the principal direction defined for the intra-uterine probe 10 while the width of an element is defined as the dimension of said element along the transverse direction defined for the intrauterine probe 10.

[0049] In the present case, the principal direction is along the axis X on figure 3 and the transverse direction is along the axis Y on the same figure. The principal direction corresponds in practice to the introduction direction of the probe 10.

[0050] In the present case, the length L of the principal portion 26 is equal to the dimension of the sides AB and CD and the width I of the principal portion 26 is equal to the dimension of the sides AD and CD.

[0051] The side AB is the distal end in so far as it the side, which will be the first in contact with the fetus 14’s head 16 when the intra-uterine probe 10 will be inserted during the labor.

[0052] The width I of the principal portion 26 is comprised between 1 .5 cm and 2.0 cm.

[0053] The length L of the principal portion 26 is comprised between 3 cm and 4.5 cm.

[0054] According to the example of figure 1 , the first lateral wing 28 (wing of the left) has the shape of a trapeze ADEF, in a plane parallel to both the axis X and the axis Y.

[0055] Advantageously, the trapezoidal shape of the first lateral wing 28 features a rounded outline, as visible on figure 3. Therefore, the first lateral wing 28 cannot hurt the patient when the intra-uterine probe 10 is inserted during the labor.

[0056] The width of the first lateral wing 28 can be defined as the height hi of the trapeze ADEF. This dimension is named first width hi hereinafter.

[0057] The first width hi is comprised between 0.7 cm and 1 .5 cm.

[0058] The ratio between the first width hi and the width I of the principal portion 26 is comprised between 70% and 100%.

[0059] A maximum length and a minimum length can also be defined for the first lateral wing 28.

[0060] The maximum length is the largest dimension of the first lateral wing 28 along the principal direction X whereas the minimum length is the largest dimension of the first lateral wing 28 along the principal direction X.

[0061] The maximum length is labelled L1 in figure 3 and will be named the first maximum length L1.

[0062] Similarly, the minimum length is labelled 11 in figure 3 and will be named the first minimum length 11 .

[0063] In the present case, the first minimum length 11 is equal to the dimension of EF and the first maximum length L1 is equal to the dimension of AD.

[0064] The first minimum length 11 is comprised between 1 .5 cm and 2.0 cm.

[0065] The first maximum length L1 is equal to the length L of the principal portion 26. In addition, the ratio between the first minimum length 11 and the first maximum length L1 is comprised between 40% and 60%.

[0066] The trapeze comprises two parallel sides AD and EF and lateral sides AF and DE.

[0067] The first lateral side AF is shorter than the second lateral side DE.

[0068] The ratio between the dimensions of the first lateral side AF and the second lateral side DE of the trapeze shape is comprised between 85% and 95%.

[0069] According to the example of figure 1 , the second lateral wing 30 (wing of the left) also has the shape of a trapeze BCGH, in a plane parallel to both the axis X and the axis Y.

[0070] Advantageously, the trapezoidal shape of second lateral wing 30 features a rounded outline, as visible on figure 3. Therefore, the second lateral wing 30 cannot hurt the patient when the intra-uterine probe 10 is inserted during the labor.

[0071] Similarly to the case of the first lateral wing 28, a second width h2, a second minimum length I2 and a second maximum length L2 can be defined for the second lateral wing 30.

[0072] With the notation of figure 3, 12 = GH and L2 = BC.

[0073] As, in this specific case, the two lateral wings 28 and 30 are symmetrical with relation to the principal portion 26, the following relations are fulfilled: 11 =12, L1 =L2 and h1 =h2.

[0074] This notably implies that the ratio between the second minimum length I2 and the second maximum length L2 is comprised between 40% and 60%.

[0075] Furthermore, the ratio between the second width h2 and the width I of the principal portion 26 is comprised between 70% and 100%.

[0076] In addition, the ratio between the dimensions of the lateral sides of the second lateral wing 30 is comprised between 85% and 95%.

[0077] This results in the fact that the sum of the widths hi and h2 of the lateral wings 28 and the width I of the principal portion 26 is comprised between 3.0 cm and 5.0 cm.

[0078] Therefore, the dimensions of the principal portion 26 can be reduced as much as possible in order to obtain a flat contact surface 24 that limits artefacts, while the two lateral wings 28, 30 hold the intra-uterine probe 10 in place on the head 16 of the fetus 14.

[0079] The body 12 is made in silicone.

[0080] The two lateral wings 28, 30 are elastically deformable. In particular, the two lateral wings 28, 30 are not rigid, but flexible. Such a property allows the contact surface 24 to be easily inserted when the cervix is dilated, thanks to the flexible lateral wings 28, 30, which can bend during the insertion.

[0081] Moreover, the two lateral wings 28, 30 are able to adapt to the curvature of the head 16 of the fetus 14 without bending. In a particular embodiment, the two lateral wings 28, 30 are independent one from the other. By “independent”, it is meant that a deformation applied to one lateral wing 28, 30 does not cause deformation on the other lateral wing 30, 28.

[0082] For instance, the thicker principal portion 26 hinders the propagation of deformation from one lateral wing 28, 30 to the other.

[0083] The sensor 18 inserted in the body 12 can be any sensor 18 appropriate to control the temporal evolution of a physical value during the labour.

[0084] For instance, the sensor 18 is an electroencephalography sensor 18 or a near-infrared spectroscopy sensor 18.

[0085] According to a preferred embodiment, several sensors 18 are inserted inside the body 12.

[0086] In particular, an association of an electroencephalography sensor or a near-infrared spectroscopy sensor is particularly advantageous.

[0087] This is the case of the intra-uterine probe 10 of figure 1 .

[0088] So as to ensure a proper contact with the head 16 of the fetus 14, the principal portion 26 is also provided with openings 32 for the electrodes of the electroencephalography sensor 18 and openings 34 for the near-infrared spectroscopy sensor 18.

[0089] In particular, the sensor 18 is only located inside the principal portion 26 of the contact surface 24. By “only”, it is meant that the electroencephalography sensor 18 is not located inside the two lateral wings 28 and 30.

[0090] To this end, the principal portion 26 presents a maximal thickness T1 , taken along a thickness direction Z, perpendicular to the principal direction X and to the axis Y, as illustrated on figure 4, comprised between 3.0 mm and 5.0 mm.

[0091] As the sensor 18 is only located inside the principal portion 26, the two lateral wings 28 and 30 can be designed thinner than the principal portion 26. For instance, the ratio between a minimal thickness T2 of the two lateral wings 28 and 30, taken along the thickness direction Z, and the thickness T 1 of the principal portion 26 is comprised between 1 / 6 and 1 / 3.

[0092] For example, the minimal thickness T2 of the two lateral wings 28 and 30 is comprised between 0.5 mm and ... 1 .6 mm.

[0093] Advantageously, at least a part, taken along the Y axis, of the two lateral wings 28 and 30 features a constant thickness equal to the minimal thickness T2.

[0094] For instance, said part features a width w, taken along the Y axis, comprised between

[0095] 5 mm and 10 mm. In particular, the ratio between said width w and the height hi , h2 of the two lateral wings 28 and 30 is comprised between 1 / 4 and 1 / 2 and / or the ratio between said width w and half of the total width of the contact surface 24, taken along the Y axis, is comprised between 1 / 6 and 1 / 3.

[0096] As illustrated on figure 4, the contact surface 24 comprises a transitory portion 35 located between each lateral wing 28, 30 and the principal portion 26.

[0097] The transitory portion 35 features a variable, in particular, progressive, thickness ranging from the minimal thickness T2 near the lateral wing 28, 30, to the maximal thickness T1 near the principal portion 26.

[0098] As it can be seen on figures 1 and 4, the contact surface 24 features a flat side Fs, configured to be in contact with the fetus head 16 when the intra-uterine probe 10 is in position, and a raised side Rsopposite the flat side Fs. The raised side Rsis located toward the uterine wall when the intra-uterine probe 10 is in position.

[0099] In other words, the change in thickness along the contact surface 24 occur only from the raised side of the contact surface 24.

[0100] Concerning the optical openings 34, the light is conveyed from a remote light source though fibers 36 and a final prism.

[0101] As apparent from figure 1 (right), the body 12 comprises a compartment 38 in which the control elements of the sensor 18 are inserted.

[0102] According to the case, the control element may be control cable or fibers for a fibered component.

[0103] The holding portion 22 is prolonging the principal portion 26 along the principal direction X.

[0104] The holding portion 22 is substantially rectangular but more extended along the principal direction X.

[0105] The holding portion 22 is a support for the compartment 38.

[0106] In the case of figure 1 , the width of the holding portion 22 is the same as the width of the principal portion 26.

[0107] Concerning the length, the sum of the length of the holding portion 22 and of the length of the principal portion 26 is comprised between 20 cm and 30 cm.

[0108] Such holding portion 22 and compartment 38 form a sheath allowing the manipulation of the probe 10 as a "guide".

[0109] The holding portion 22 presents for instance a relative longitudinal rigidity (limited, preferably zero, elongation along the X axis) and is flexible in order to adapt to the curvature between the head 16 of the fetus 14 and the entrance of the vagina of the patient.

[0110] Therefore, the holding portion 22 facilitates the introduction of the probe 10. This also enables to secure the constituent elements of the probe 10 and its material support and improve handling.

[0111] As explained before, such Intra-uterine probe 10 has an appropriate shape for the insertion when the cervix is dilated during the labour.

[0112] Such shape is also adapted to be hold by the fetal head 16 in a passive way.

[0113] Such shape allows an increased contact surface 24 optimizing the passive fixation on fetal head 16 thanks to uterine wall without increasing the width for probe 10 introduction through the cervix. It also avoids a probe 10 rotation during fetal movements.

[0114] This enables to alleviate the problem is the risk of miscontact between probe 10 and fetal head 16 because of fetal movements without active mechanisms to fix the probe 10 on the head 16, which is pretty invasive.

[0115] The increased surface contact allows a force transmission of uterine wall through probe 10 increasing the friction force between head 16 and probe 10.

[0116] The width also limits the risk of probe 10 rotation during fetal head 16 rotation during labour.

[0117] The head 20 is only sufficiently smooth and not too rigid to enable hand manipulation of the intra-uterine probe 10.

[0118] Other embodiments of the surface contact of the intra-uterine probe 10 may be considered.

[0119] Some examples are provided on figure 5.

[0120] As apparent from this figure, it may be considered lateral wings with different shapes providing with the above-mentioned advantages, although the shape presented on figure 3 is the preferred one.

[0121] All these embodiments share at least the property according to which the contact surface 24 has a principal portion 26 surrounded by two lateral wings 28 and 30.

Claims

CLAIMS1 Intra-uterine probe (10) adapted to be held by a fetus (14), the intra-uterine probe (10) comprising- a body (12) defining an interior volume, the body (12) having a contact surface (24), adapted to be in contact with the head (16) of the fetus (14),- at least one sensor (18) in the interior volume, the contact surface (24) having a principal portion (26) surrounded by two lateral wings (28, 30).2.- Intra-uterine probe according to claim 1 , wherein the principal portion (26) is rectangular.3.- Intra-uterine probe according to claim 1 or 2, wherein, for each lateral wing (28, 30), the ratio between a width of the lateral wing (28, 30) and a width of the principal portion (26) is comprised between 70% and 100%.4.- Intra-uterine probe according to any one of claims 1 to 3, wherein, for each lateral wing (28, 30), the ratio between a minimum length and a maximum length is comprised between 40% and 60%.5.- Intra-uterine probe according to any one of claims 1 to 4, wherein, for each lateral wing (28, 30), the maximum length is equal to the length of the principal portion (26), and / or each lateral wing (28, 30) has a trapeze shape, the trapeze shape comprising two parallel sides and lateral sides, the ratio between the dimensions of the lateral sides of the trapeze shape being comprised between 85% and 95%.6.- Intra-uterine probe according to any one of claims 1 to 5, wherein the intra-uterine probe (10) comprises an electroencephalography sensor and a near-infrared spectroscopy sensor, the electroencephalography sensor and the near-infrared spectroscopy sensor being in the interior volume.7.- Intra-uterine probe according to any one of claims 1 to 6, wherein the at least one sensor (18) is a fibered component.8.- 1 ntra-uteri ne probe according to any one of claims 1 to 7, wherein the intra-uterine probe (10) comprises a holding portion (22), the holding portion (22) being in contact with the contact surface (24) and holding fibers (36).9.- Intra-uterine probe according to claim 8, wherein the length of the holding portion (22) and the principal portion (26) is comprised between 20 cm and 30 cm.10.- Intra-uterine probe according to any one of claims 1 to 9, wherein the width of the principal portion (26) is comprised between 1 .5 cm and 2.0 cm.1 1.- . Intra-uterine probe according to any one of claims 1 to 10, wherein the sum of the widths of the lateral wings (28, 30) and the width of the principal portion (26) is comprised between 3.0 cm and 5.0 cm.

12. - Intra-uterine probe according to any one of claims 1 to 11 , wherein each lateral wing (28, 30) has a minimal thickness (T1 ) and the principal portion (26) has a maximal thickness (T2), the minimal thickness (T1 ) being strictly inferior to the maximal thickness (T2).

13. - Intra-uterine probe according to claim 12, wherein the contact surface (24) comprises at least one transitory portion (35) located between the lateral wing (28, 30) and the principal portion (26), the transitory portion (35) featuring a variable progressive thickness from the minimal thickness (T1 ) to the maximal thickness (T2).

14. - Intra-uterine probe according to claim 12 or 13, wherein for each lateral wing (28, 30), the ratio between the minimal thickness (T1 ) of the lateral wing (28, 30) and the maximal thickness (T2) of the principal portion (26) is comprised between 1 / 6 and 1 / 3.

15. - Intra-uterine probe according to any one of claims 1 to 14, wherein each lateral wing (28, 30) is elastically deformable.

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