JP2008104470A - Abdominal impedance type fetal growth estimating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an abdominal impedance type fetal growth estimating apparatus by which a fetal growth is easily estimated. <P>SOLUTION: An abdominal impedance is measured by an abdominal impedance measuring means 1. Next, combined weight of a fetus and an amniotic fluid of a subject based on the measured abdominal impedance is estimated by a fetus/amniotic fluid combined weight estimating means 2. The number of weeks of gestation of the subject is obtained by a means 3 for obtaining the number of weeks of gestation. Then, the amount of the amniotic fluid of the subject is estimated from the obtained number of weeks of gestation of the subject by a means 4 for estimating the amount of the amniotic fluid. The weight of the amniotic fluid of the subject based on the estimated amount of the amniotic fluid is estimated by a means 5 for estimating a weight of the amniotic fluid. Finally, the weight of the fetus of the subject is estimated by subtracting the previously estimated weight of the amniotic fluid of the subject from the previously estimated combined weight of the fetus and the amniotic fluid of the subject by a means 6 for estimating a weight of a fetus. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an abdominal impedance type fetal growth status estimation device that measures impedance (abdominal impedance) in the abdomen and estimates a fetal growth status.

  Conventionally, in order to grasp the growth status of the fetus, the cross section of the abdomen of the pregnant woman is scanned with ultrasound, an ultrasound image about the fetus is generated, and an index indicating the growth status of the fetus is measured from the generated ultrasound image An apparatus that uses an apparatus (for example, disclosed in Patent Document 1 or Patent Document 2), or generates an MRI image of a cross section of a pregnant woman's abdomen, and measures an index indicating a fetal growth status from the generated MRI image. It was done by using.

JP-A-9-327457 JP 2005-58536 A

  However, the above-described conventional apparatus requires specialized knowledge or labor for handling and use.

  Therefore, the present invention aims to solve the conventional problems as described above, and an object thereof is to provide an abdominal impedance type fetal growth status estimation device that can easily know the fetal growth status. To do.

  The abdominal impedance type fetal growth status estimation device of the present invention has a current-carrying electrode and a measurement electrode arranged in a row in the waist direction, and the current-carrying electrode and the measurement electrode are placed in a row in the waist direction of the subject. Abdominal impedance measuring means for measuring the abdominal impedance when placed, and fetal growth status estimating means for estimating the growth status of the fetus of the subject based on the abdominal impedance measured by the abdominal impedance measuring means.

  Further, the fetal growth status estimation means includes: a fetus / amniotic fluid synthetic weight estimation means for estimating a synthetic weight of the subject's fetus and amniotic fluid based on the abdominal impedance measured by the abdominal impedance measurement means; Estimated by the amniotic fluid amount estimating means, the amniotic fluid amount estimating means for estimating the amount of amniotic fluid of the subject based on the pregnancy week number of the subject acquired by the pregnant week number acquiring means, and the amniotic fluid amount estimating means The amniotic fluid weight estimating means for estimating the amniotic fluid weight of the subject based on the amount of amniotic fluid of the subject, and the amniotic fluid weight estimating means estimated from the combined weight of the fetus and the amniotic fluid estimated by the fetal / amniotic fluid synthetic weight estimating means And fetal weight estimating means for estimating the fetal weight of the subject by subtracting the amniotic fluid weight of the subject.

  Since the abdominal impedance type fetal growth status estimation device of the present invention estimates the fetal growth status by measuring the abdominal impedance when the energization electrodes and measurement electrodes are arranged in a row in the waist direction of the subject, specialized knowledge is obtained. You can easily know the fetal development situation without needing or labor.

  Moreover, in estimating the growth status of the subject's fetus, the combined weight of the subject's fetus and amniotic fluid is estimated by the fetal / amniotic fluid synthetic weight estimation means based on the measured abdominal impedance, while the pregnancy week number acquisition means The number of gestational weeks is obtained, and then the amount of amniotic fluid of the subject is estimated based on the obtained number of weeks of pregnancy of the subject by the amniotic fluid amount estimating means, and then the amount of amniotic fluid of the subject is estimated by the amniotic fluid weight estimating means. Estimating the subject's amniotic fluid weight, and estimating the subject's fetal weight by subtracting the previously estimated subject's amniotic fluid weight from the combined weight of the subject's fetus and amniotic fluid previously estimated by the fetal weight estimation means, You can easily and surely know the fetal development status.

  The form of the abdominal impedance type fetal growth status estimation apparatus according to the present invention will be described with reference to the functional block diagram shown in FIG. The abdominal impedance type fetal growth status estimation device of the present invention is constituted by an abdominal impedance measurement means 1 and a fetal growth status estimation means 7.

  The abdominal impedance measuring means 1 has a current-carrying electrode and a measurement electrode arranged in a row in the waist direction, and a current-carrying electrode and a measurement electrode are arranged in a row in the waist direction of the subject (pregnant woman, the same applies hereinafter). Measure the abdominal impedance at the time. Here, the energizing electrode is composed of a plurality of parts for flowing current to the abdomen, and the measuring electrode is composed of a plurality of elements, and detects a potential difference generated in the abdomen when current flows from the energizing electrode. Is to do.

  The fetal growth status estimation means 7 comprises a fetal / amniotic fluid synthetic weight estimation means 2, a pregnancy week acquisition means 3, an amniotic fluid amount estimation means 4, an amniotic fluid weight estimation means 5 and a fetal weight estimation means 6; Based on the measured abdominal impedance, the growth status of the subject's fetus is estimated.

  The fetal / amniotic fluid synthetic weight estimating means 2 estimates the synthetic weight of the subject's fetus and amniotic fluid based on the abdominal impedance measured by the abdominal impedance measuring means 1.

  The pregnancy week acquisition means 3 acquires the pregnancy week of the subject.

  The amniotic fluid amount estimation means 4 estimates the amount of amniotic fluid of the subject based on the number of pregnancy weeks of the subject acquired by the pregnancy week number acquisition means 3.

  The amniotic fluid weight estimating means 5 estimates the amniotic fluid weight of the subject based on the amount of amniotic fluid of the subject estimated by the amniotic fluid amount estimating means 4.

  The fetal weight estimating means 6 estimates the fetal weight of the subject by subtracting the amniotic fluid weight of the subject estimated by the amniotic fluid weight estimating means 5 from the combined weight of the fetus and amniotic fluid estimated by the fetal / amniotic fluid synthetic weight estimating means 2. .

  According to the abdominal impedance type fetal growth state estimating apparatus configured as described above, the abdominal impedance is measured by the abdominal impedance measuring means 1 and then the fetus of the subject based on the measured abdominal impedance by the fetal / amniotic fluid synthetic weight estimating means 2. On the other hand, the pregnancy weight of the subject is obtained by the pregnancy time acquisition means 3, and then the amount of amniotic fluid of the subject based on the obtained pregnancy week of the subject by the amniotic fluid estimation means 4 Then, the amniotic fluid weight estimation means 5 estimates the amniotic fluid weight of the subject based on the estimated amount of amniotic fluid of the subject, and the fetal weight estimation means 6 previously estimates the combined weight of the subject's fetus and amniotic fluid. The fetal weight of the subject is estimated by subtracting the previously estimated weight of the amniotic fluid from the subject. Or require knowledge of, without it takes time and effort, it is possible to know in brief sure about fetal development situation.

  Hereafter, the Example in the form mentioned above is demonstrated concretely.

  First, a specific configuration of the abdominal impedance type fetal growth status estimation apparatus according to the present invention will be described with reference mainly to the external view shown in FIG. 2 and the main part block diagram shown in FIG.

  The abdominal impedance fetal growth status estimation device is roughly configured by a support unit 10 and an operation unit 20.

  The support portion 10 has a flexible rod-like body 11 in which the curvature of the support surface 11 a in the longitudinal direction can be freely changed according to the size of the abdomen 100 of the pregnant woman, and a row in the longitudinal direction of the support surface 11 a of the rod-like body 11. The four electrodes 12a, 12b, 12c, and 12d are arranged on the holding surface 11b opposite to the support surface 11a on which the four electrodes 12a, 12b, 12c, and 12d are arranged. Here, of the four electrodes 12a, 12b, 12c, and 12d, the two electrodes arranged on the outside are the energizing electrodes 12a and 12b for flowing current to the abdomen 100, and the two electrodes arranged on the inside are the abdomen Measurement electrodes 12 c and 12 d for detecting a potential difference generated at 100.

  The operation unit 20 includes an input unit 22 and a display unit 23 on the outer surface of the casing 21, and includes a power supply unit 24, a current generation unit 25, a voltage detection unit 26, a time measurement unit 27, a storage unit 28, a calculation unit 29, and a control unit. 30 is provided inside the housing 21.

  Here, the power supply unit 24 supplies power to each part of the electrical system of the present apparatus. The timer unit 27 measures time. The input unit 22 includes a power switch 22a for starting power supply from the power supply unit 24, a measurement switch 22b for starting measurement of abdominal impedance, and a numeric keypad 22c for inputting subject information such as the number of pregnancy weeks. Become.

  Here, the current generator 25 generates a current having a predetermined frequency (50 kHz) for energizing the abdomen 100 based on the control from the controller 30. The voltage detector 26 detects the voltage generated between the measurement electrodes 12c and 12d when this current is passed between the energization electrodes 12a and 12b.

  Further, here, the storage unit 28 is based on subject information such as the number of pregnancy weeks input from the numeric keypad 22c, and a voltage generated between the measurement electrodes 12c and 12d when a current is passed between the energization electrodes 12a and 12b. In order to calculate the amount of amniotic fluid based on the abdominal impedance calculated by the calculating unit 29 and the combined weight of the fetus and amniotic fluid based on the abdominal impedance (equation (1) below) and the number of gestational weeks To calculate fetal weight based on formula (2) below, formula for converting amniotic fluid to amniotic fluid weight (3) below, combined fetal and amniotic fluid weight and amniotic fluid weight (4) below, various calculation result information, control programs and other various information are stored.

T = a × Z + b (1)
^{AFV = c × S 4 - d} × S 3 + e × S 2 - f × S + g ··· (2)
AFW = AFV x h (3)
FW = T-AFW (4)

  Where T is the combined weight of the fetus and amniotic fluid, Z is the abdominal impedance, AFV is the amount of amniotic fluid, S is the number of weeks of pregnancy, AFW is the amniotic fluid weight, FW is the fetal weight, and a and b are the abdominal impedance and the combined fetal and amniotic fluid. Regression coefficients (constants) representing the relationship with weight, c, d, e, f and g represent regression coefficients (constants) representing the relationship between the pregnancy cycle and the amount of amniotic fluid, and h represents the density (constant) of amniotic fluid. For the constants, a = 53.1, b = 15.3, c = 0.0015, d = 0.275, e = 12.476, f = 172.51, g = 737.41, h = It is desirable to set it to 1.0.

  It should be noted that the combined weight of fetus and amniotic fluid obtained by the above equation (1) is as shown in FIG. 6 and generally obtained by the ultrasonic method (reference method) that is estimated to have good accuracy. High correlation with synthetic weight (see R). Moreover, said (2) Formula formulates the graph which shows the relationship between the amount of amniotic fluid and pregnancy weeks as shown in FIG. In addition, as shown in FIG. 8, the fetal weight obtained by the above equation (4) is correlated with the fetal weight obtained by the ultrasonic method (reference method), which is generally considered to have good estimation accuracy (R See) is high.

The calculation unit 29
(I) Calculate the abdominal impedance based on the current detected by the current detector 25 and the voltage detected by the voltage detector 26 at a frequency of 50 kHz.
(Ii) calculating the combined weight of the fetus and the amniotic fluid by substituting the previously calculated abdominal impedance into the formula (1) stored in the storage unit 28;
(Iii) calculating the amount of amniotic fluid by substituting the number of gestational weeks input from the numeric keypad 22c into the equation (2) stored in the storage unit 28;
(Iv) The amniotic fluid weight is calculated by substituting the previously calculated amniotic fluid amount into the equation (3) stored in the storage unit 28;
(V) calculating the fetal weight by substituting the previously calculated fetal and amniotic fluid weight and amniotic fluid weight into the equation (4) stored in the storage unit 28;
(Vi) Calculate various other data.

  The display unit 23 displays various information in the input stage, measurement stage, and result stage (instructions for inputting the number of pregnancy weeks in the input stage, measurement progress in the measurement stage, and fetal development status in the result stage (from the numeric keypad 22c). (Including the input number of pregnancy weeks and the amount of amniotic fluid and fetal weight calculated by the calculation unit 29).

The control unit 30
(I) Based on the ON signal from the power switch 22a, the power supply from the power supply unit 24 to each part of the electrical system of the apparatus is controlled,
(Ii) Based on the ON signal from the measurement switch 22b, the generation of a current having a frequency of 50 kHz from the current generator 25 is controlled,
(Iii) controlling the calculation of the abdominal impedance by the calculation unit 29 based on the current detected by the current detection unit 26 and the voltage detected at that time by the current of the frequency of 50 kHz generated from the current generation unit 25;
(Iv) Control the calculation of the combined weight of the fetus and amniotic fluid by the calculation unit 29 based on the abdominal impedance calculated by the calculation unit 29 and the equation (1) stored in the storage unit 28;
(V) controlling the calculation of amniotic fluid volume by the calculation unit 29 based on the number of weeks of pregnancy input from the numeric keypad 22c and the equation (2) stored in the storage unit 28;
(Vi) controlling the amniotic fluid amount calculated by the calculating unit 29 based on the amount of amniotic fluid calculated by the calculating unit 29 and the equation (3) stored in the storage unit 28;
(Vii) controlling the calculation of the fetal weight by the calculation unit 29 based on the combined weight of the fetus and amniotic fluid calculated by the calculation unit 29 and the amniotic fluid weight and the equation (4) stored in the storage unit 28;
(Viii) Instruction for inputting the number of gestational weeks in the input stage by the display unit 23, the progress of measurement in the measurement stage, the fetal development status in the result stage (gestation week, amount of amniotic fluid, fetal weight, etc.), other input stage, measurement stage , Control the display of various information in the results stage,
(Ix) Control various other information.

  Here, why the fetal weight can be estimated based on the abdominal impedance will be described.

  As shown in the abdominal cross-sectional view of FIG. 9, the current flowing between the energization electrodes 12a and 12b arranged in the waistline direction mainly flows through the abdominal muscles on the abdominal side and the abdominal muscles on the back side as paths (c1, c2). Moreover, as shown in the abdominal cross-sectional view in the early stage of pregnancy in FIG. 10A and the abdominal cross-sectional view in the late stage of pregnancy in FIG. 10A, the abdominal muscles grow as the development of the fetus progresses and the abdomen becomes larger. 9 and 10, the voltage detected in the measurement electrodes 12c and 12d arranged in the waistline direction so as to be in line with the energization electrodes 12a and 12b is the size of the abdomen (that is, the extension of the abdominal muscles). ) To change. Therefore, the fetal weight is calculated by subtracting the amniotic fluid weight (amniotic fluid weight) related to the size of the abdomen during pregnancy from the abdominal impedance (mainly abdominal muscle impedance) determined based on the current flow and the detected voltage. Can be estimated. The factors other than fetal weight, amniotic fluid volume, and abdominal muscles (subcutaneous fat, internal organs, visceral fat, spine) have a very small effect on the size of the abdomen. The weight can be estimated. 9 and 10A and 10B, S represents subcutaneous fat, V represents amniotic fluid / fetus / internal organ / visceral fat, M represents muscle (abdominal muscle), and B represents the spine.

  In the above, the configuration of the energization electrodes 12a and 12b, the measurement electrodes 12c and 12d, the current generation unit 25, the voltage detection unit 26, the storage unit 28, the calculation unit 29, the control unit 30, and the power supply unit 24 is an abdominal impedance measurement. Corresponds to means 1. Further, the configuration of the storage unit 28, the calculation unit 29, the control unit 30, and the power supply unit 24 corresponds to the fetal / amniotic fluid synthesis weight estimation unit 2, the amniotic fluid amount estimation unit 4, the amniotic fluid weight estimation unit 5 and the fetal weight estimation unit 6. To do. Further, the configuration of the input unit 22, the storage unit 28, the calculation unit 29, the control unit 30, and the power supply unit 24 corresponds to the pregnancy week number acquisition unit 3.

  Next, the operation and operation of the abdomen of the abdominal impedance type fetal growth status estimation apparatus according to the present invention will be described mainly using the flowchart shown in FIG.

  First, when the power switch 22a is turned on, power is supplied from the power supply unit 24 to each part of each electrical system, and a pregnancy week number input and measurement standby screen as shown in FIG. Then, based on the control from the control unit 30, when the number of gestational weeks is input with the numeric keypad 22 c, the input gestational week is displayed on the display unit 23, and the input is performed in the storage unit 28. The number of gestational weeks is stored (step S1). Next, the control unit 30 determines whether or not the measurement switch 22b is turned on (step S2). Here, when the measurement switch 22b is not turned on (NO in step S2), the input of the number of pregnancy weeks and the measurement standby state process are repeated until the measurement switch 22b is turned on.

  Subsequently, when the support surface 11a side on which the energization electrodes 12a and 12b and the measurement electrodes 12c and 12d are disposed is pressed against the front portion of the abdomen 100 and the measurement switch 22b is turned on (YES in step S2). Is generated between the current electrodes in the current generator 25 based on the control from the controller 30, and the voltage generated between the measurement electrodes 12c and 12d in the voltage detector 26 at this time. The abdominal impedance is calculated based on the generated 50 kHz frequency current and the detected voltage in the calculating unit 29, and the calculated abdominal impedance is stored in the storage unit 28 (step S3). During this step, that is, during the measurement of the abdominal impedance, the display 23 displays as shown in FIG.

  Subsequently, based on the control from the control unit 30, the calculation unit 29 assigns the combined weight of the fetus and amniotic fluid by substituting the abdominal impedance stored in the storage unit 28 into the equation (1) stored in the storage unit 28. The calculated combined weight of fetus and amniotic fluid is stored in the storage unit 28 (step S4).

  Subsequently, based on the control from the control unit 30, the calculation unit 29 calculates the amount of amniotic fluid by substituting the number of gestation weeks stored in the storage unit 28 into the equation (2) stored in the storage unit 28, In the storage unit 28, the calculated amount of amniotic fluid is stored (step S5).

  Subsequently, based on the control from the control unit 30, the calculation unit 29 calculates the amniotic fluid weight by substituting the amount of amniotic fluid stored in the storage unit 28 into the equation (3), and in the storage unit 28, The calculated amniotic fluid weight is stored (step S6).

  Subsequently, based on the control from the control unit 30, the calculation unit 29 substitutes the combined weight of the fetus and amniotic fluid stored in the storage unit 28 and the amniotic fluid weight stored in the storage unit 28 into the equation (4). Thus, the fetal weight is calculated, and the calculated fetal weight is stored in the storage unit 28 (step S7).

  Subsequently, based on control from the control unit 30, the display unit 23 displays the number of weeks of pregnancy, the amount of amniotic fluid, and the weight of the fetus stored in the storage unit 28 for a certain period of time as shown in FIG. 5C (step S8). ).

  Subsequently, a re-measurement inquiry screen as shown in FIG. 5D is displayed, and it is determined whether or not the measurement switch 22b is turned on (step S9). Here, when the measurement switch 22b is turned on (YES in step S9), the process returns to the pregnancy week number input and measurement standby screen (step S1), and the above-described series of operations and operation processing processes are possible. On the other hand, if the measurement switch 22b is not turned on even after the measurement by the time measuring unit 27 has elapsed for a predetermined time (NO in step S9), the power is automatically turned off, and the series of operations and operation processing steps are completed.

It is a functional block diagram which shows functionally the structure of the abdominal impedance type fetal growth condition estimation apparatus of this invention. It is an external view which shows the external appearance structure of the abdominal-impedance type fetal growth condition estimation apparatus of this invention, (a) is a front view, (b) is a top view. It is a waist block diagram shown about the principal part which comprises the abdominal-impedance type | formula fetal growth condition estimation apparatus of this invention. It is a flowchart figure which shows the procedure of operation and operation | movement of the abdominal-impedance type | formula fetal growth condition estimation apparatus of this invention. It is a display screen figure from a measurement start to an end. It is a graph which shows the correlation with the synthetic | combination weight of the fetus and the amniotic fluid calculated | required with the ultrasonic method, and the synthetic weight of the fetus and the amniotic fluid calculated | required with the computing equation. It is a graph which shows the relationship between the amount of amniotic fluid and pregnancy weeks. It is a graph which shows the correlation of the fetal weight calculated | required with the ultrasonic method, and the fetal weight calculated | required with the computing equation. It is a figure which shows the electric current path | route with respect to the abdomen of a pregnant woman. It is abdominal sectional drawing for comparing the abdominal section by the difference in the size of the stomach of a pregnant woman, (a) is an abdominal sectional view in the early pregnancy, and (b) is an abdominal sectional view in the second trimester.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Abdominal impedance measurement means 2 Fetal and amniotic fluid synthetic | combination weight estimation means 3 Pregnancy week acquisition means 4 Amniotic fluid amount estimation means 5 Amniotic fluid weight estimation means 6 Fetal weight estimation means 7 Fetal growth condition estimation means 10 Support part 11 Rod 11a Support surface 11b Holding surface 12a, 12b Conductive electrode 12c, 12d Measuring electrode 13a, 13b Handle 20 Operation unit 21 Housing 22 Input unit 22a Power switch 22b Measurement switch 22c Numeric keypad 23 Display unit 24 Power supply unit 25 Current generation unit 26 Voltage detection unit 27 Timekeeping Unit 28 Storage Unit 29 Calculation Unit 30 Control Unit 100 Abdomen

Claims (2)

An abdominal impedance measuring means for measuring an abdominal impedance when the energizing electrodes and the measurement electrodes are arranged in a row in the waist direction of the subject, having an energization electrode and a measurement electrode arranged in a row in the waist direction When,
Fetal growth status estimation means for estimating the growth status of the subject's fetus based on the abdominal impedance measured by the abdominal impedance measurement means;
An abdominal impedance type fetal growth status estimation device comprising: The fetal growth status estimation means includes
Fetal and amniotic fluid synthetic weight estimating means for estimating the combined weight of the fetus and amniotic fluid based on the abdominal impedance measured by the abdominal impedance measuring means;
Means for obtaining the number of pregnancy weeks of the subject;
Amniotic fluid amount estimation means for estimating the amount of amniotic fluid of the subject based on the number of pregnancy weeks of the subject acquired by the pregnancy week number acquisition means;
Amniotic fluid weight estimating means for estimating the amniotic fluid weight of the subject based on the amount of amniotic fluid of the subject estimated by the amniotic fluid amount estimating means;
The fetal weight estimation means for estimating the fetal weight of the subject by subtracting the amniotic fluid weight of the subject estimated by the amniotic fluid weight estimation means from the combined weight of the fetus and amniotic fluid estimated by the fetal / amniotic fluid synthetic weight estimation means When,
An abdominal impedance type fetal growth status estimation device comprising:

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