FIELD OF THE INVENTION

Embodiments of the disclosure relate to a device for sampling fetal scalp blood. BACKGROUND

Hypoxia is a clinical sign which may lead to perinatal asphyxia. Approximately four million newborn children die annually worldwide. Almost one quarter of these deaths are caused by perinatal asphyxia. The clinical signs following severe perinatal asphyxia are traditionally referred to as hypoxic ischemic encephalopathy (HIE). These signs include encephalopathy, and multi-organ failure. The newborn may show no breathing at birth or labored breathing later, poor feeding, seizures and/or epileptic activity, poor muscle tone, acidosis, elevated kidney and liver function tests, heart rate abnormalities, DIC, lethargy and behavioral changes and more. Currently, fetal hypoxia is generally monitored using heart rate monitors (FHR).

FHR is not an accurate means to measure hypoxia and is associated with high rates of false positive readings. Many labor and delivery units rely only on FHR as an indication ofhypoxia of the fetus in order to make clinical decisions at birth such as when to stop labor and when to resort to a cesarean section or an instrumental birth. In some cases additional tests such as taking a blood sample from the fetal scalp are included. This blood sample can be used to measure blood gases/parameters (pH, PO2 ,PC _) or blood Lactate. An additional recent method for testing hypoxia is STAN (ST analysis) of the fetal electrical pulse obtained by an electrode attached to the fetal scalp. An increase in T-wave amplitude is the result of increased glycogen depletion in fetal myocardial cells during metabolic acidosis. The T/QRS ratio increases as fetal hypoxia increases with consequent metabolic acidosis during labor. STAN was found to reduce the operative birth and fetal blood sampling, but the effect on fetal blood acidosis which reflects the hypoxic conditions is still not clear. Current monitoring methods may result in false positive indications which in turn may lead to unnecessary surgery, thereby placing the mother and fetus at risk. On the other hand, current monitoring methods may also result in false negatives which can lead to brain damage and even death of the fetus. For example, a clinical test aimed at establishing the relationship between blood oxygen level (pulse Oximeter) and fetal stress failed to show a correlation between the two (Steven L. Bloom, M et al, Fetal Pulse Oximetry and Cesarean Delivery, in engl j med 355;21 2006).

Lactic acid is mainly produced in muscle cells and red blood cells. It is formed by glycolysis when the body breaks down carbohydrates for energy production during times of low oxygen levels. By monitoring the increase in lactic acid levels or by measuring fluctuations in lactic acid levels the attending physician can decide on proceeding with an operative delivery when the fetus shows early signs of hypoxia.

Increased levels of LDH enzyme have been reported after neonatal asphyxia (KarlssonMl, Wiberg-Itzel E, Chakkarapani E, Blennow M, Winbladh B, Thoresen M., Lactate dehydrogenase predicts hypoxic ischaemic encephalopathy in newborn infants: a preliminary study. Acta Paediatr. 2010 Aug;99(8): 1139-44).

The substantial rise in LDH, after organ damage and asphyxia directly after birth (cord blood), resulting from organ damage following asphyxia and its different rates of disappearance from plasma (5-36 h), makes the enzyme a potential predictor of the severity of the hypoxic-ischemic insult in the perinatal period.

The current practice for sampling fetal blood from the fetal scalp is complicated and cumbersome. After obtaining a lithotomy position of the mother during birth, a hollow conus like device is introduced into the birth canal. The fetus' scalp is viewed by attaching a light source to the conus. The fetalus' scalp needs to be isolated from debris and blood in the surrounding environment so the scalp is carefully cleaned. Paraffin is then introduced in order for the blood drop to be created. The blood drop is aspirated by a long rod with a glass pipette at its edge introduced from the external environment to the fetus' scalp. The acquired blood drop is introduced to an external blood analyzer for measurement of levels of blood gases or Lactate or both . This whole procedure takes approximately 20-30 minutes.

A hand-mounted device for obtaining a sample of blood from the scalp of a fetus during parturition and for measuring the pH of the blood sample was previously described in US Patent Application No. 20040092843. However, in order to measure oxidation levels based on pH values, relatively large volumes of blood should be sampled.

There is thus a need in the art for a non-expensive device which is easily operated and that requires a minimal amount of time and blood volume for measuring fetal blood levels of Lactate and/or Lactate Dehydrogenase (LDH).

SUMMARY OF THE INVENTION

The present invention, in some embodiments thereof, relates to measurement of perinatal asphyxia properties during labor, such as Lactate and/or Lactate Dehydrogenase (LDH) and or other patient physiological parameters (for example, AST, ALT, IL-2,6 etc.) and, more particularly, but not exclusively, to such measuring using biochemical and or photometrical methods.

According to some embodiments there is provided herein a device (e.g., a handheld device) for measuring a fetal blood related parameter such as fetal blood levels of Lactate and/or Lactate Dehydrogenase (LDH), the device comprising: a means for mounting the device to an operator's hand or finger; an element for cleaning the scalp; a lancet extendable from a distal end of the device for incising tissue; and a capillary extendable from the distal end of the device for collecting a sample of blood for measuring fetal blood levels of Lactate and/or Lactate Dehydrogenase (LDH).

According to some embodiments, there is provided herein a system for measuring fetal blood Lactate and or Lactate Dehydrogenase (LDH), the system comprising: a device for measuring fetal blood levels of Lactate and/or Lactate Dehydrogenase (LDH), the device comprising: a means for mounting the device to an operator's hand or finger; an element for cleaning the scalp; a lancet extendable from a distal end of the device for incising tissue; and a capillary extendable from the distal end of the device for collecting a sample of blood for measuring fetal blood levels of Lactate and/or Lactate Dehydrogenase (LDH); and an analyzer configured to determine Lactate and/or Lactate Dehydrogenase (LDH) levels in the sample. According to some embodiments, there is provided herein a method for determining the levels of Lactate and/or Lactate Dehydrogenase (LDH), the method comprising: mounting on an operator's hand or finger a device comprising: a means for mounting the device to an operator's hand or finger; an element for cleaning the scalp; a lancet extendable from a distal end of the device for incising tissue; and a capillary extendable from the distal end of the device for collecting a sample of blood; cleaning a fetal' s scalp; incising a fetal' s scalp tissue; and collecting a blood sample for Lactate and/or Lactate Dehydrogenase (LDH) analysis.

According to some embodiments, there is provided herein a method for measuring fetal blood Lactate and/or Lactate Dehydrogenase (LDH) levels, comprising: inserting a hand-mounted device in proximity of a presenting part of a fetus in parturition; isolating a region adjacent to a distal end of the device from a surrounding region; cleaning the presenting part of a fetus with the cleaning element; advancing a lancet from the distal end of the device and incising tissue in the presenting part of the fetus; and advancing a capillary from the distal end of the device and collecting a sample of blood from the incised tissue for Lactate and/or Lactate Dehydrogenase (LDH) analysis.

According to some embodiments, the device/system further includes a strip for loading the blood sample from the capillary. The strip may further include a means for determining Lactate and/or Lactate Dehydrogenase (LDH) levels. According to some embodiments, the means for mounting the device to an operator's hand is in the form of a thimble, a glove, a finger cot, or a finger ring to which the device is attached. According to some embodiments, the element for cleaning the scalp may be disposable. The element for cleaning the scalp may be configured to be operated manually. The element for cleaning the scalp may be configured to be activated automatically upon contact with the fetal scalp. The element for cleaning the scalp may include a sterilizing material. According to some embodiments, the device may include a sterilizing material.

According to some embodiments, the lancet may be slidably mounted in a lancet guide tube. The lancet may be connected by a lancet actuator rod to a lancet actuator located at a proximal end of the lancet guide tube. The lancet actuator may be configured to be activated manually. The lancet actuator may be configured to be activated automatically upon contact with the fetal scalp.

According to some embodiments, the capillary may be slidably mounted in a capillary guide tube. The capillary may be connected by a capillary actuator rod to a capillary actuator located at a proximal end of the capillary guide tube. The capillary actuator may be configured to be activated manually. The capillary actuator may be configured to be activated automatically upon contact with the fetal scalp.

According to some embodiments, the analyzer is configured to apply colorimetric and/or photometric assay, designed to measure the presence and/or concentration of a biochemical analyte in the sample by a color change and/or the light emitted, respectively, which is indicative of the presence or concentration of the analyte (such as, but not limited to, Lactate and/or Lactate Dehydrogenase (LDH).

According to some embodiments, measured lactate levels of preacidemia 4.2- 4.8 mg/dL Acidemia > 4.8 mg dL are indicative of Asphyxia. According to some embodiments, measured LDH levels of between 2000-4000 IU/L or above 40001U L are indicative of Asphyxia. According to some embodiments, the method includes delivering the fetus, if a perinatal hypoxia state is diagnosed. Delivering the fetus may include expeditious delivery by a cesarean section or by an operative delivery selected from a group consisting of vacuum and forceps delivery. According to some embodiments, there is provided herein a device for measuring fetal blood levels of Lactate and/or Lactate Dehydrogenase (LDH), comprising: a sampling unit comprising: an element for cleaning the scalp; a lancet extendable from a distal end of the device for incising tissue; and a capillary extendable from the distal end of the device for collecting a sample of blood for Lactate and/or Lactate Dehydrogenase (LDH) analysis. The sampling unit may be a part of or is attached to a stick. The stick may he telescopic. The sampling unit may be permanently attached to the stick. The sampling unit may be detachable from the stick- According to some embodiments, there is provided herein a kit for measuring fetal blood levels of Lactate and/or Lactate Dehydrogenase (LDH), the kit comprising: a device comprising: a means for mounting the device to an operator's hand or finger; an element for cleaning the scalp; a lancet extendable from a distal end of the device for incising tissue; and a capillary extendable from the distal end of the device for collecting a sample of blood for measuring fetal blood levels of Lactate and or Lactate Dehydrogenase (LDH); and a strip for loading the blood sample from the capillary.

Further embodiments and the full scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

Following are some examples of some embodiments of the invention, also indicating some possible combination between various features of some embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a device for measuring fetal blood levels of Lactate and/or Lactate Dehydrogenase (LDH), according to some embodiments;

FIG. 2 is a schematic view of a device for measuring fetal blood levels of Lactate and or Lactate Dehydrogenase (LDH) mounted on a finger of an operator, according to some embodiments; and

FIG. 3 is a schematic view of a device for measuring fetal blood levels of

Lactate and/or Lactate Dehydrogenase (LDH) mounted on a finger of an operator and wherein the lancet is exposed, according to some embodiments. DETAILED DESCRIPTION

In the following description, various aspects of the disclosure will be described. For the purpose of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the different aspects of the disclosure. However, it will also be apparent to one skilled in the art that the disclosure may be practiced without specific details being presented herein. Furthermore, well-known features may be omitted or simplified in order not to obscure the disclosure.

This disclosure introduces a device or method for measuring fetal blood levels of Lactate and or Lactate Dehydrogenase (LDH), comprising: a means for mounting the device to an operator's hand or finger; an element for cleaning the scalp; a lancet extendable from a distal end of the device for incising tissue; and a capillary extendable from the distal end of the device for collecting a sample of blood for Lactate and/or Lactate Dehydrogenase (LDH) analysis. The device may further comprise a strip or loading the blood sample from the capillary.

As used herein, according to some embodiments, the term "Lactate" refers also to lactic acid or lactate ion CH3CH(OH)C02 ^" .

As used herein, according to some embodiments, the term "Lactate Dehydrogenase" or "LDH" refers to the enzyme Lactate Dehydrogenase which forms L-lactate from pyruvate and vice versa.

This disclosure introduces a device for measuring fetal blood levels of Lactate and/or Lactate Dehydrogenase (LDH), comprising: a means for mounting the device to an operator's hand or finger. The means for mounting the device include but are not limited to a thimble or a glove or a finger cot or a finger ring to which the device is mounted.

In some embodiments of this invention disclosed is a device or method for measuring fetal blood levels of Lactate and/or Lactate Dehydrogenase (LDH), comprising: an element for cleaning the scalp of the fetus prior to sampling of blood. As used herein the "element for cleaning" could be disposable, could be operated manually or could be activated automatically upon contacting the fetal scalp.

As used herein, according to some embodiments, the term "element for cleaning" refers to a brush, a tube which provides a flow or air or liquid, a tube which provides a suction force, a sponge which could be fixed, rotating and or vibrating. The Element for cleaning may be attached to the device or to the other finger of the examiner or operator.

As used herein the "element for cleaning" could be disposable, could be operated manually, could be activated automatically upon contacting the fetal scalp. The element for cleaning could be fixed, could rotate, could vibrate or could move back and forth.

In some preferred embodiments of this invention the "element for cleaning" also includes a sterilizing agent or material which could be applied prior to and\or after collection of a blood sample. Exemplary sterilizing agents may include Ethanol chlorhexidine and Oil Paraffin which could be applied during or after the cleaning procedure. The sterilizing material could be applied to the scalp pre, during or post incision with the lancet.

This disclosure introduces a device or method for measuring fetal blood levels of Lactate and/or Lactate Dehydrogenase (LDH), comprising a lancet extendable from a distal end of the device for incising tissue. The lancet could be a needle or a spine or a spike. The lancet could incise or prick the fetal scalp.

In some preferred embodiments of this invention the lancet could be disposable, could be operated manually, could be activated automatically upon contacting the fetal scalp. The lancet could be slidably mounted in a lancet guide tube, the lancet could be connected by a lancet actuator rod to a lancet actuator located at a proximal end of the lancet guide tube, the lancet actuator could be activated manually or could be activated automatically upon contacting the fetal scalp. In some preferred embodiments the lancet could be a plain syringe, a needle, a razor, a blade or a device for making a small incision or pricking in the scalp such as a knife or a blade. This disclosure introduces a device or method for measuring fetal blood levels of Lactate and/or Lactate Dehydrogenase (LDH), comprising a capillary extendable from the distal end of the device for collecting a sample of blood for Lactate and/or Lactate Dehydrogenase (LDH) analysis.

In some embodiments of the invention the capillary could be slidably mounted in a capillary guide tube. The capillary could be connected by a capillary actuator rod to a capillary actuator located at a proximal end of the capillary guide tube. The capillary actuator could be activated manually or automatically upon contact with the fetal scalp. The capillary could be heparinized capillary or nonheparinized capillary.

In some embodiments of the invention the device may further comprise a strip on which the blood sample may be loaded and analyzed. The strip could be an integral part of the device or a disposable strip. The strip may include the assays for determination of Lactate and/or Lactate Dehydrogenase (LDH) levels or may be used just for the purpose of transferring the blood sample to a measuring device which measures the Lactate and/or Lactate Dehydrogenase (LDH) levels. The strip may further comprise the means for determining Lactate and/or Lactate Dehydrogenase (LDH) levels such as an enzymatic, chemical, colorimetric or photometric assay. The strip may be referred to as the "Reaction strip".

In some embodiments of the invention the device, method or system for measuring fetal blood Lactate and/or Lactate Dehydrogenase (LDH) further comprises a system for determining Lactate and/or Lactate Dehydrogenase (LDH) levels. The device, method or system for determining Lactate Dehydrogenase (LDH) levels in the fetal blood could include enzymatic, chemical, colorimetric or photometric reactions, which are designed to measure the presence or concentration of a biochemical analyte in a sample. The device, method or system for determining Lactate Dehydrogenase (LDH) levels in the fetal blood could include a colorimetric or photometric reaction that measures the change in color or emitted light respectively and which is indicative of the presence or concentration of the analyte. An exemplary assay for determination of LDH levels includes a reaction in which the LDH catalyzes the reversible oxidation of L-Lactate (a supplied substrate) to Pyruvate with the concurrent reduction of β-Nicotinamide Adenine Dinucleotide (NAD) to β-Nicotinamide Adenine Dinucleotide (reduced form) (NADH). The system monitors the rate of change in absorbance at 340 nm over a fixed-time interval. The rate of change in absorbance is directly proportional to the activity of LDH in the sample.

The system for determining Lactate levels in the fetal blood could include an enzymatic reaction or a chemical reaction.

An exemplary assay for determination of Lactate is based on an enzymatic coupled reaction that results in the conversion of a tetrazolium salt (iodonitrotetrazolium (INT)) into a red color formazan by diaphorase.

The system for determining Lactate and/or Lactate Dehydrogenase (LDH) levels could use a colorimetric assay system which is designed to measure the presence or concentration of a biochemical analyte in a sample by a color change which is indicative of the presence or concentration of the analyte. It can also be electric and measure electrons.

Reactions 1 and 2 occur simultaneously. Lactate in the blood is specifically oxidized by LODox to pyruvate; LODox is reduced to LODred. LODred is oxidized with ferricyanide, an electron mediator, to LODox, which again oxidizes lactate. Thus, LOD repeatedly oxidizes lactate and changes the mediator to the reduced form, ferrocyanide. The accumulated ferrocyanide is finally oxidized to ferricyanide, as shown in equation 3, by an electrode with a potential of +0.5 V. The anodic current is measured by an amperometer.

The system for determining Lactate and/or Lactate Dehydrogenase (LDH) levels could be an integral part of the device or could be a detachable add-on to the device. The system for determining Lactate and or Lactate Dehydrogenase (LDH) levels could measure lactate levels, Lactate Dehydrogenase (LDH) levels or both.

This disclosure introduces a device or method for determining if a fetus has perinatal asphyxia by measuring fetal blood levels of Lactate and/or Lactate Dehydrogenase (LDH), using a device comprising: a means for mounting the device to an operator's hand or finger; an element for cleaning the scalp; a lancet extendable from a distal end of the device for incising tissue; and a capillary extendable from the distal end of the device for collecting a sample of blood for Lactate and/or Lactate Dehydrogenase (LDH) analysis. The device or method could be used for determining if a fetus has perinatal asphyxia. In some embodiments of the invention the device or method for determining if a fetus has perinatal asphyxia is by measuring fetal blood levels. As used herein, according to some embodiments, the term "perinatal asphyxia" or "neonatal asphyxia" or "birth asphyxia" refers to a medical condition resulting from deprivation of oxygen to a newborn infant that lasts long enough during the birth process to cause physical harm, usually to the brain.

Perinatal hypoxia has gradient clinical manifestations based on the degree of the hypoxia, the time length and the vulnerability of the fetus/neonate. Hypoxic ischemic encephalopathy (HIE) could be categorized to mild, moderate and severe HIE. There is a correlation between the drop in the fetal blood PH levels and degree of fetal asphyxia.

Perinatal asphyxia state can be determined by analyzing fetal blood Lactate and/or Lactate Dehydrogenase (LDH) levels. While normal lactate levels could be in the range of: 0.S to 2.2 mmol/L ( up to 4.2 mg/dL), in the Asphyxia state the Asphyxia lactate levels could be in the range of: preacidemia 4.2-4.8 mg/dL and Acidemia > 4.8 mg/dL)

While normal LDH levels could be in the range of Up to 2000IU/L, in the Asphyxia state the Asphyxia LDH levels could be in the range of 2000-4000 1U/L (Warning levels) or > 4000 IU/L (Pathologic).

In some embodiments of the invention the method for measuring fetal blood Lactate and/or Lactate Dehydrogenase (LDH) levels comprises: inserting a hand- mounted Lactate and/or Lactate Dehydrogenase (LDH) device in proximity to a presenting part of a fetus in parturition; isolating a region adjacent to a distal end of the Lactate and/or Lactate Dehydrogenase (LDH) device from a surrounding region; cleaning the presenting part of a fetus with the cleaning element; advancing a lancet from the distal end of the Lactate and/or Lactate Dehydrogenase (LDH) device and incising tissue in the presenting part of the fetus; and advancing a capillary from the distal end of the Lactate and/or Lactate Dehydrogenase (LDH) device and collecting a sample of blood from the incised tissue for Lactate and/or Lactate Dehydrogenase (LDH) analysis. In a further embodiment, the levels of Lactate and/or Lactate Dehydrogenase (LDH) measured according to the method above are used as an indication for perinatal asphyxia state. In embodiments of the invention, the levels of Lactate and/or Lactate Dehydrogenase (LDH) could be used in combination with heart rate monitors (FHR) or computerized CTG (Fetal cardiotocographia) or STAN or any combination thereof.

In a preferred embodiment of the invention, once the levels of Lactate and or Lactate Dehydrogenase (LDH) are measured, a decision on the next clinical intervention could be made. Such clinical intervention may include, if birth is far off and the uterine cervix is not dilated, the decision to perform a cesarean section. If birth is imminent, an operative delivery (Vacuum extraction or forceps) may be applied.

In a preferred embodiment of the invention the method or system or device could be used to determine whether the fetus (or embryo) is in a state of perinatal hypoxia and an immediate action to deliver the fetus could be taken. This action may be expeditious delivery by a cesarean section or by an operative delivery (Vacuum or forceps).

In an embodiment of the invention, the method or device for measuring fetal blood Lactate and/or Lactate Dehydrogenase (LDH) levels comprises isolating a region adjacent to a distal end of the Lactate and/or Lactate Dehydrogenase (LDH) device from a surrounding region. Isolation may be achieved by including in the device a cap which could be pressed gently over the fetal scalp, attached via an adhesive material or by vacuum force. In some embodiments of the invention, the method or device for measuring fetal blood Lactate and/or Lactate Dehydrogenase (LDH) is used together with a heart rate monitor. In some preferred embodiments of the invention, the method or device for measuring fetal blood Lactate and or Lactate Dehydrogenase (LDH) is used in combination with pH measurement, fetal blood Lactate and/or Lactate Dehydrogenase (LDH) may be used in combination with additional parameters such as temperature, AST and ALT enzymes levels and additional biomarkers such as S100B, Ubiquitin Carboxyl-Terminal Hydrolase LI Protein (UCHL1), Cleaved TAU(C-Tau) Microtuble-Associated Protein 2 (MAP2) Myelin Basic Protein (MBP ), Spectrin Breakdown Products (SBDP ) Microtuble-Associated Protein 2 (MAP 2), Myelin Basic Protein (MBP ) Spectrin breakdown products (SBDP) Brain -Derived Neutrophic Factor (BDNF ) Activin A, Matrix Methaloproteinase 9(MMP -9) Vascular endothelial growth factor (VEGF) Platelet derived growth factor receptor Beta (PDGFRb) TTirombospodin-l(TSP-l) CRP, TGF alfa, ILlBeta, IL-6, IL-8 TNF Tumor necrotizing Factor alfa Granolocyte Colony Stimulating Factor (G- CSF ) MicroRNA, Exosomes and combinations thereof.

In some embodiments of the invention, the method or system or device comprise means for isolating the fetal scalp from a surrounding region such that the device includes an addition which could be in the form of a cup or of a bell. This addition to the device, which isolates the fetal scalp from a surrounding region, could house the element for cleaning the scalp, the lancet extendable from a distal end of the device, the capillary extendable from the distal end of the device or the strip which may be referred to as the reaction strip, or any combination thereof.

In some embodiments of the invention, enclosed is a device for measuring fetal blood levels of Lactate and/or Lactate Dehydrogenase (LDH), comprising: a. an element for cleaning the scalp; b. a lancet extendable from a distal end of the device for incising tissue; and c. a capillary extendable from the distal end of the device for collecting a sample of blood for Lactate and or Lactate Dehydrogenase (LDH) analysis all referred to as the sampling unit.

In further embodiments of the invention, the sampling unit is part of or is attached to a stick. The stick could be telescopic. In some embodiments, the sampling unit could be permanently attached to the stick or could be detachable from the stick. The detachable sampling unit could be replaced by a sterile sampling unit.

In some embodiments of the invention, the device or method for measuring fetal blood Lactate and/or Lactate Dehydrogenase (LDH) comprises an alerting system to alert the caregiver, e.g. a nurse or a physician, that the values of the fetal blood Lactate levels are in the range of pre-determined parameters. Range of pre-determined parameters could be: preacidemia 4.2-4.8 mg/dL and Acidemia > 4.8 mg/dL or that the Asphyxia LDH levels could be in the range of 2000-4000 IU/L (Warning levels) or > 4000 IU/L (Pathologic). In some embodiments of the invention the device, method or system for measuring fetal blood Lactate and/or Lactate Dehydrogenase (LDH) comprises an alerting system to alert the caregiver, e.g. a nurse or a physician, that the fetus is in a state of perinatal asphyxia. The alert could be in the form of a predetermined color e.g. red, yellow or green. The alert could be in the form of a sound and/or could be sent as a notification to a mobile device such as a phone or a tablet.

The device may be referred to as "Fetusafe".

Reference is now made to Figs. 1-3. Fig. 1 is a schematic view of a device 100 for measuring fetal blood related parameter, such as levels of Lactate and/or Lactate Dehydrogenase (LDH), according to some embodiments, FIG. 2 is a schematic view of device 100 on a finger of an operator, according to some embodiments, and FIG. 3 is a schematic view of device 100 mounted on a finger of the operator and wherein the lancet is exposed, according to some embodiments.

Device 100 includes a device housing 102 and a mounting member 104 configured to be mounted on the operator's finger (as shown in Figs. 2-3). Mounting member 104 may have any shape or form that will allow securing device 100 on the operator's hand or finger. In this case, mounting member 104 is shown to have two ring structures, which are adapted to encircle the finger and stabilize device 100. Device 100 further includes a needle shield 106 which is distal to and may be contiguous with housing 102. Needle shield 106 is configured to cover needle 110 (Fig. 3) and to protect from accidental piercing before the operator has positioned device 100 in the right position. Needle shield 106 has a hole at a distal end face thereof for facilitating the exit of needle 110 upon operation using activatio switch 108. In this case, needle 110 is configure for both piercing and collecting a sample of the fetal blood. Device 100 further includes a strip 114 on which the blood sample may be loaded and analyzed (for example, the strip may include assays for determination of Lactate and/or Lactate Dehydrogenase (LDH) levels or may be used for the purpose of transferring the blood sample to a measuring device which measures the Lactate and/or Lactate Dehydrogenase (LDH) levels.

Examples

Example 1

In order to study the effect of hypoxia on Lactate and plasma levels, we used a hypoxia model of a rat (Sprague-Dawley) as our model in which rats were exposed to normoxic or hypoxic conditions. A mixture of 8% oxygen in nitrogen was provided respiratory to the animals through a special mask developed to present the correct concentration of oxygen. A control group of rats were sedated and allowed to breathe the air in the room. Blood was collected from the tip of the tail and lactate levels were measured using standard equipment. Blood was collected at 6 time intervals in order to demonstrate the accumulation of Lactate during time of hypoxia. Each group contained 3-5 animals.

The results are shown in Table 1 and represent the average plasma levels of Lactate (+std.dev).

Our results show a significant difference between the control and test groups. In the control group, lactate levels remained low as opposed to the hypoxia group, in which levels of lactate increase rapidly (Table 1). Lactate levels had risen by 3 folds within 10 min and remained rather constant thereafter.

Table 1 : Average blood levels of lactate in rat hypoxia model:

Example 2

Healthy human volunteers are measured for the levels of lactate and LDH using the device. A peripheral hypoxia in one of the volunteer arms is artificially created by depriving the arm from blood supply for a short period of time. During this period, lactate and LDH levels are determined using our device ("Fetusafe"). In parallel, O2 levels are measured by pulse-oximeter on the finger of the volunteer. The measurements are taken at different time points including time 0 which gives indication to the normal levels of LDH for the volunteer.