Contraction monitor

Claim 2

A contraction monitor adapted to be operatively disposed in contact with the abdominal wall of a mother during labor to sense muscle contractions in the abdominal wall, comprising: a frame having a substantially fixed relationship with the abdominal wall of the mother; first means constructed to contact the abdominal wall and responsive to a muscle contraction in the abdominal wall for moving relative to the frame; first optical means having characteristics for emitting light, the first optical means having a fixed relationship relative to one of the frame and the first means; second optical means including portions having a fixed relationship with the other of the frame and the first means and operatively coupled to the first means to provide a variable separation in distance from the first optical means dependent upon the movements of the first means relative to the frame, the second optical means having characteristics responsive to the light emitted by the first optical means for providing an output signal having characteristics dependent upon the distance separating the first optical means and the second oPtical means but substantially independent of any temperature variations in the second optical means; and indicating means responsive to the output signal from the second optical means for providing an indication of the magnitude of the muscle contraction in the abdominal wall of the mother.

Claim 3

The monitor recited in claim 1 further comprising: a first wall portion included in the frame and having a substantially planar configuration; a second wall portion included in the frame and having a substantially planar configuration, the second wall portion having a substantially fixed spaced relationship with the first wall portion of the frame; and a flexible member included in the first means and disposed between the first wall portion and the second wall portion of the frame, the flexible member having first portions fixed with respect to the frame and second portions movable with the first means with respect to the frame, and a particular one of the first optical means and the second optical means being disposed on the second portions of the flexible member for movement with the first means and the second portions of the flexible member relative to the other one of the first optical means and the second optical means.

Claim 4

The monitor set forth in claim 2 further comprising: a first light emitting element included in the first optical means, the first light emitting element having characteristics for emitting a first light in the direction of the first wall portions of the frame; a first photosensor included in the second optical means, the first photosensor being responsive to the first light from the first light emitting element to provide a first signal having characteristics dependent upon the magnitude of the muscle contraction; and the indicating means including second means responsive to the first signal from the first photosensor for amplifying the first signal to provide the output signal.

Claim 5

The monitor recited in claim 3 further comprising: a second light emitting element included in the first optical means, the second light emitting element having characteristics for emitting a second light in the direction of the second wall portions of the frame; a second photosensor included in the second optical means, the second photosensor being responsive to the second light from the second light emitting element to provide a second signal having characteristics dependent upon the magnitude of the muscle contraction; the second means, being constructed to provide a differential amplification in the characteristics of the first signal from the first photosensor and the second signal from the second photosensor to provide the output signal.

Claim 6

The monitor recited in claim 4 wherein: the first photosensor is constructed and disposed to provide the first signal with an increasing magnitude with muscle contractions of increasing magnitude; the second photosensor is constructed and disposed to provide the second signal with a decreasing magnitude with muscle contractions of increasing magnitude; the second means has properties responsive to the increasing magnitude of the first signal and the decreasing magnitude of the second signal to provide the output signal with an increasing magnitude related to increasing differences in the amplitudes of the first and second signals; and third means are provided to regulate the operation of the first and second light emitting elements in accordance with the sum of the first signal and the second signal.

Claim 7

The monitor recited in claim 1 wherein the indicating means include second means responsive to the output signal from the second optical means for introducing the output signal to the first optical means in a polarity to regulate the operation of the first optical means in accordance with the characteristics of the output signal for the production in the output signal of characteristics substantially linearly related to the distance between the first Optical means and the second optical means over an extended range of such distances.

Claim 8

An optical strain gauge for measuring the magnitude of an external force including: a supporting structure; first means operatively coupled to the supporting structure and responsive to the external force for deflecting with respect to the supporting structure in a direction substantially perpendicular to the supporting structure to provide in the first means a strain proportional to the magnitude of the external force; a source of current; second means including first portions having a fixed relationship with the first means for deflection with the first means and including second portions having a fixed relationship with the supporting structure, the second means having optical characteristics responsive to the current from the source and responsive to variations in the distance between the first and second portions of the second means to provide an output signal having characteristics dependent upon the strain in the first means; and means responsive to the output signal for providing an indication of the magnitude of the external force.

Claim 9

An optical strain gauge for measuring the magnitude of an external force including: a supporting structure; first means operatively coupled to the supporting structure and responsive to the external force for deflecting with respect to the supporting structure in a direction substantially perpendicular to the supporting structure to provide in the first means a strain proportional to the magnitude of the external force; a source of current; second means including first portions having a fixed relationship with the first means for deflection with the first means and including second portions having a fixed relationship with the supporting structure, the second means having optical characteristics responsive to the current from the source and responsive to variations in the distance between the first and second portions of the second means to provide an output signal having characteristics dependent upon the strain in the first means; and means responsive to the output signal for providing an indication of the magnitude of the external force.

Claim 10

The strain gauge recited in claim 7 wherein: the second means has variable output characteristics dependent upon the distance between the first and second portions of the second means; third means are associated with the source and the second means and are responsive to the output signal from the second means to provide the current from the source with a substantially constant magnitude regardless of variations in the output characteristics of the second means; and the second means has properties responsive to the current of substantially constant magnitude from the source to provide the output signal with characteristics which vary substantially linearly with variations in the distance between the first and second portions of the second means over a first range of deflections; wherein fourth means are associated with the second means to provide the output signal with characteristics which vary substantially linearly with variations in the deflection of the first means over a second range of deflections wider than the first range of deflections.

Claim 11

The strain gauge recited in claim 7 wherein the second means includes: a first light emitting element having a fixed relationship to one of the first means and the supporting structure, the first light emitting element being responsive to the source of current to emit a first light; a first photosensor having a fixed relationship with the other of the first means and the supporting structure, the first photosensor having characteristics responsive to the first light to provide a first signal having characteristics dependent upon the characteristics of the first light and upon the distance between the first light emitting diode and the first photosensor; a second light emitting element having a fixed relationship with one of the first means and the supporting structure, the second light emitting element being responsive to the source of current to emit a second light; a second photosensor having a fixed relationship with the other of the first means and the supporting structure, the second photosensor having characteristics responsive to the second light to provide a second signal having characteristics dependent upon the characteristics of the second light and upon the distance between the second light emitting diode and the second photosensor; the first light emitting element and the first photosensor being disposed and the second light emitting element and the second photosensor being disposed to provide for a decrease in the distance between the first light emitting element and the first photosensor simultaneously with an increase in distance between the second light emitting element and the second photosensor in accordance with the deflections of the first means to provide for an increase in the amplitude of the first signaL from the first photosensor at the same time as a decrease in the amplitude of the second signal from the second photosensor; and third means responsive to the first signal and the second signal for differentially amplifying the first signal and the second signal to provide the output signal.

Claim 12

A gauge for measuring strain, including: a frame; a flexible member having first portions fixed with respect to the frame and second portions movable with respect to the frame in response to the strain to be measured; a power source; first means fixed to at least one of the frame and the second portions of the flexible member and operatively coupled to the power source for emitting light in the direction of at least the other of the frame and the second portions of the flexible member; and second means fixed to at least the other of the frame and the second portions of the flexible member to be separated from the first means by a distance dependent upon the movement of the second portion of the flexible member, the second means being responsive to the light emitted by the first means to provide an output signal having characteristics dependent upon the distance between the first and second means; means responsive to the output signal for providing an indication dependent upon the characteristics of such signal; and control means responsive to the output signal and operatively coupled to the first means for regulating the energizing of the first means in accordance with the characteristics of the output signal to provide, over a wide range of movements of the flexible member, a substantially linear relationship between the characteristics of the output signal and the movements of the flexible member.

Claim 13

A gauge for measuring strain, including: a frame; a flexible member having first portions fixed with respect to the frame and second portions movable with respect to the frame in response to the strain to be measured; a power source; first means fixed to at least one of the frame and the second portions of the flexible member and operatively coupled to the power source for emitting light in the direction of at least the other of the frame and the second portions of the flexible member; and second means fixed to at least the other of the frame and the second portions of the flexible member to be separated from the first means by a distance dependent upon the movement of the second portion of the flexible member, the second means being responsive to the light emitted by the first means to provide an output signal having characteristics dependent upon the distance between the first and second means; means responsive to the output signal for providing an indication dependent upon the characteristics of such signal; and control means responsive to the output signal and operatively coupled to the first means for regulating the energizing of the first means in accordance with the characteristics of the output signal to provide, over a wide range of movements of the flexible member, a substantially linear relationship between the characteristics of the output signal and the movements of the flexible member.

Claim 14

The gauge recited in claim 10 wherein the frame includes first portions extending on one side of the second portions of the flexible member and second portions extending on the other side of the second portions of the flexible member, and the first means comprises: a first member mounted on one of the first portions of the frame and the second portions of the flexible member for emitting a first light; a second member mounted on one of the second portions of the frame and the second portions of the flexible member for emitting a second light; a first photosensitive member mounted on the other of the first portions of the frame and the second portions of the flexible member, the first photosensitive member being responsive to the first light to provide a first signal with characteristics increased in magnitude with increased movements in the flexible member relative to the frame; a second photosensitive member mounted on the other of the second portions of the frame and the second portions of the flexible member, the second photosensitive member being responsive to the second light to provide a second signal with characteristics increased in magnitude with decreased movements in the flexible member relative to the frame; and third means responsive to the first signal from the first photosensitive member and the second signal from the second photosensitive member to provide the output signal in accordance with the difference in characteristics of the first and second signals.

Claim 15

The gauge recited in claim 11 wherein the control means include means responsive to the sum of the first and second signals to regulate the energizing of the first and second members in accordance with the sum of the first and second signals to provide, over a wide range of movements of the flexible member, the substantially linear relationship between the characteristics of the output signal and the movements of the flexible member.

Claim 16

The gauge set forth in claim 12 wherein the first and second light emitting members are connected in series and wherein means are responsive to the sum of the signals from the first and second photosensitive members to regulate the energizing of the first and second members.

Claim 17

The gaUge recited in claim 12 wherein the first photosensitive member is constructed to provide in the first signal characteristics which vary with temperature variations in the first photosensitive member and the second photosensitive member is constructed to provide in the second signal characteristics which vary with variations in the temperature of the second photosensitive member, and the second means further comprises: fourth means for biasing the first photosensitive member, the fourth means including a first degenerative feedback loop coupled to the first photosensitive member and the fourth means to vary the bias in the first photosensitive member in a direction to reduce the the variations in the characteristics of the first signal from the first photosensitive member with variations in the temperature of the first photosensitive member; fifth means for biasing the second photosensitive member, the fifth means including a second degenerative feedback loop coupled to the second photosensitive member and the fifth means to vary the bias in the second photosensitive member in a direction to reduce the variations in the characteristics of the second signal from the second photosensitive member with the variations in temperature of the second photosensitive member; and the third means being differentially responsive to the first signal and the second signal to provide the output signal.

Claim 18

The gauge set forth in claim 10 wherein means extend from the flexible member to a position external of the frame to respond to the strain and to produce a movement of the flexible member in accordance with such response and wherein means are included for producing a movement of the flexible frame in accordance with the response of such responsive means while maintaining such responsive means in a particular disposition to respond to the strain.

Claim 19

The gauge set forth in claim 15 wherein the responsive means includes a button and wherein the means for maintaining the lugs in the particular disposition includes a member fixed at a first position to the frame, at a second position to the button and at a third position to the flexible member to provide compensatory movements at the second and third positions for maintaining the button at a particular angle relative to the frame.

Claim 20

In combination for monitoring the heart rate of a fetus and the labor contractions of a mother, comprising: a fetal heart rate monitor constructed to be coupled to the abdominal wall of the mother and to be responsive to the heart beat of the fetus to provide a first electrical signal having characteristics dependent upon the heart rate of the fetus; a contraction monitor coupled to the abdominal wall of the mother and including an optical strain gauge having properties for providing a second electrical signal with characteristics dependent upon the magnitude of and the rate of the contractions of the mother; signal conditioning means responsive to the characteristics of the first signal and the characteristics of the second signal to vary the characteristics of the first electrical signal in accordance with the characteristics of the second electrical signal; and means responsive to the characteristics of the first electrical signal from the signal conditioning means for providing an indication of such characteristics.

Claim 21

In combination for monitoring the heart rate of a fetus and the labor contractions of a mother, comprising: a fetal heart rate monitor constructed to be coupled to the abdominal wall of the mother and to be responsive to the heart beat of the fetus to provide a first electrical signal having characteristics dependent upon the heart rate of the fetus; a contraction monitor coupled to the abdominal wall of the mother and including an optical strain gauge having properties for providing a second electrical signal with characteristics dependent upon the magnitude of and the rate of the contractions of the mother; signal conditioning means responsive to the characteristics of the first signal and the characteristics of the second signal to vary the characteristics of the first electrical signal in accordance with the characteristics of the second electrical signal; and means responsive to the characteristics of the first electrical signal from the signal conditioning means for providing an indication of such characteristics.

Claim 22

The combination recited in claim 17 wherein the optical strain gauge includes: at least one member for emitting a first light; at least one sensor movable relative to the light emitting member a distance dependent upon the magnitude of the contraction of the abdominal wall of the mother and responsive to the light emitted by the light emitting member to provide the second electrical signal with particular characteristics dependent upon the distance separating the member and the sensor; whereby the particular characteristics of the second electrical signal provide an indication of the magnitude of the contraction.

Claim 23

The combinatIon recited in claim 18 where: means are operatively associated with the sensor for providing the particular characteristics of the second electrical signal with linear characteristics related to the distance between the member and the sensor over a wide range of such distances.

Claim 24

A contraction monitor for monitoring the contractions of muscles in the abdominal wall of a mother during labor, the monitor including: a frame constructed to have a substantially fixed relationship with the abdominal wall of the mother; a flexible member constructed to have first portions fixed with respect to the frame and second portions movable with respect to the frame to provide between the flexible member and the frame a separation distance dependent upon the movement of the second portions of the flexible member relative to the frame; first means constructed to have a substantially fixed relationship with the second portions of the flexible member and extending from the flexible member to the abdominal wall of the mother, the first means being responsive to the contractions of the muscles in the abdominal wall to vary the separation distance between the second portions of the flexible member and the frame; second means fixed to at least one of the frame and the second portions of the flexible member for emitting light in the direction of at least the other of the frame and the second portions of the flexible member; third means fixed to at least the other of the frame and the second portions of the flexible member to be separated from the second means by a distance dependent upon the variable length of the separation distance, the third means being responsive to the light emitted by the first means to provide an output signal and being responsive to the proximity of the second means to provide the output signal with characteristics dependent upon the magnitude of the muscle contractions in the abdominal wall of the mother; means responsive to the output signal for indicating the contractions of muscles in the abdominal wall of the mother during labor; and fourth means operatively coupled to the flexible member and the frame and the first means for maintaining the first means in a particular angular relationship to the frame regardless of the variations in the separation distance between the frame and the second portions of the flexible member.

Claim 25

A contraction monitor for monitoring the contractions of muscles in the abdominal wall of a mother during labor, the monitor including: a frame constructed to have a substantially fixed relationship with the abdominal wall of the mother; a flexible member constructed to have first portions fixed with respect to the frame and second portions movable with respect to the frame to provide between the flexible member and the frame a separation distance dependent upon the movement of the second portions of the flexible member relative to the frame; first means constructed to have a substantially fixed relationship with the second portions of the flexible member and extending from the flexible member to the abdominal wall of the mother, the first means being responsive to the contractions of the muscles in the abdominal wall to vary the separation distance between the second portions of the flexible member and the frame; second means fixed to at least one of the frame and the second portions of the flexible member for emitting light in the direction of at least the other of the frame and the second portions of the flexible member; third means fixed to at least the other of the frame and the second portions of the flexible member to be separated from the second means by a distance dependent upon the variable length of the separation distance, the third means being responsive to the light emitted by the first means to provide an output signal and being responsive to the proximity of the second means to provide the output signal with characteristics dependent upon the magnitude of the muscle contractions in the abdominal wall of the mother; means responsive to the output signal for indicating the contractions of muscles in the abdominal wall of the mother during labor; and fourth means operatively coupled to the flexible member and the frame and the first means for maintaining the first means in a particular angular relationship to the frame regardless of the variations in the separation distance between the frame and the second portions of the flexible member.

Claim 26

A contraction monitor recited in claim 18 wherein the frame includes first portions extending on one side of the second portions of the flexible member and second portions extending on the other side of the second portions of the flexible member, and the second means comprises: a first member mounted on one of the first portions of the frame and the second portions of the flexible member for emitting a first light; and a second member mounted on one of the second portions of the frame and the second portions of the flexible member for emitting a second light.

Claim 27

The contraction monitor recited in claim 19 wherein the third means comprises: a first photosensitive member mounted on the other of the first portions of the frame and the second portions of the flexible member, the first photosensitive member being responsive to the first light to provide a first signal with characteristics increasing in magnitude with muscle contractions of increasing magnitude in the abdominal wall of the mother; a second photosensitve member mounted on the other of the second portions of the frame and the second portions of the flexible member, the second photosensitive member being responsive to the second light to provide a second signal with characteristics increasing in magnitude with muscle contractions of decreasing magnitude in the abdominal wall of the mother; and fourth means responsive on a differential basis to the first signal from the first photosensitive member and the second signal from the second photosensitive member to provide the output signal in accordance with differences in the characteristics of the signals from the first and second photosensitive members.

Claim 28

The contraction monitor recited in claim 22 wherein the first light emitting member and the second light emitting member are connected in series, and wherein means are responsive to the sums of the signals from the first and second photosensitive members to provide a control signal, and wherein means are responsive to the control signal to regulate the operation of the first and the second light emitting members to provide a substantially linear interrelationship between the output signal and the magnitude of contractions in the abdominal wall of the mother during labor over a wide range in the magnitude of such contractions.

Claim 29

The contraction monitor recited in claim 22 wherein the first photosensitive member is constructed to provide in the first signal a gain which varies with temperature and the second photosensitive member is constructed to provide in the second signal a gain which varies with temperature, and the second means further comprises: fifth means for biasing the first photosensitive member, the fifth means including a first degenerative feedback loop coupled to the first photosensitive member to reduce the variations in the gain of the first signal from the first photosensitive member with variations in temperature; sixth means for biasing the second photosensitive member, the sixth means including a second degenerative loop coupled to the second photosensitive member for reducing the variations in the gain of the second signal from the second photosensitive member with variations in temperature; and the fourth means being differentially responsive to the first signal and the second signal to provide the output signal.

Claim 30

A construction monitor adapted to be disposed in contact with the abdominal wall of a mother to measure muscle contractions in the abdominal wall during labor, the monitor comprising: a frame including portions having a substantially planar configuration and constructed to be disposed in a substantially parallel relationship with the abdominal wall of the mother; a reed having first portions constructed to be pivotal in a first direction with respect to the frame and second portions constructed to be pivotal in a second direction opposite to the first direction simultaneously with the pivotal movements of the first portion of the reed in the first direction; means operatively coupled to the reed and to the frame for providing for the pivotal movements of the reed in the first direction with respect to the frame and for providing simultaneously for the pivotal movement of the second portions in the second direction opposite to the first portion; a button mounted on the second portions of the reed and constructed to be operably disposed in contact with the abdominal wall of the mother, the button having properties responsive to a muscle contraction and responsive to the pivotal movement of the first portion of the reed in the first direction and simultaneously to the pivotal movements of the second portion of the reed in the opposite direction to move substantially perpendicular to the abdominal wall a distance proportional to the magnitude of the muscle contraction to produce a strain in the reed; means carried by the reed for providing a signal having a magnitude proportional to the distance of movement of the button in the direction perpendicular to the abdominal wall; and means responsive to the signal provided by the last mentioned means for providing an indication of the magnitude of such signal.

Claim 31

A construction monitor adapted to be disposed in contact with the abdominal wall of a mother to measure muscle contractions in the abdominal wall during labor, the monitor comprising: a frame including portions having a substantially planar configuration and constructed to be disposed in a substantially parallel relationship with the abdominal wall of the mother; a reed having first portions constructed to be pivotal in a first direction with respect to the frame and second portions constructed to be pivotal in a second direction opposite to the first direction simultaneously with the pivotal movements of the first portion of the reed in the first direction; means operatively coupled to the reed and to the frame for providing for the pivotal movements of the reed in the first direction with respect to the frame and for providing simultaneously for the pivotal movement of the second portions in the second direction opposite to the first portion; a button mounted on the second portions of the reed and constructed to be operably disposed in contact with the abdominal wall of the mother, the button having properties responsive to a muscle contraction and responsive to the pivotal movement of the first portion of the reed in the first direction and simultaneously to the pivotal movements of the second portion of the reed in the opposite direction to move substantially perpendicular to the abdominal wall a distance proportional to the magnitude of the muscle contraction to produce a strain in the reed; means carried by the reed for providing a signal having a magnitude proportional to the distance of movement of the button in the direction perpendicular to the abdominal wall; and means responsive to the signal provided by the last mentioned means for providing an indication of the magnitude of such signal.

Claim 32

The contraction monitor recited in claim 25 wherein the first portions of the reed and the second portions of the reed normally have a substantially parallel relationship with the planar portions of the frame prior to any contractions of the muscles in the abdominal wall of the mother during labor, and the button is constructed to be responsive to the muscle contractions to move the first poRtions of the reed into a transverse relationship with the planar portions of the frame and to maintain the second portions of the reed in the substantially planar relationship with the planar portions of the frame.

Claim 33

The contraction monitor set forth in claim 26 wherein the button has a particular surface constructed to be disposed in contact with the abdominal wall with the particular axis in a particular angular relationship with the abdominal wall, the particular surface having a convex configuration to maintain a substantially constant area of contact with the abdominal wall even with slight variations in the angular relationship of the axis of the button and the abdominal wall.

Claim 34

A contraction monitor for monitoring the contractions of muscles in the abdominal wall of a mother during labor, the monitor including: a frame having a substantially fixed relationship with the abdominal wall of the mother; a flexible member having first portions fixed with respect to the frame and second portions movable with respect to the frame to provide a separation distance between the flexible member and the frame, the separation distance having a length dependent upon the movement of the second portions of the flexible member relative to the frame; first means having a substantially fixed relationship with the flexible member and extending from the flexible member to the abdominal wall of the mother, the first means responsive to the contractions of the muscles in the abdominal wall to vary the length of the separation distance between the second portions of the flexible member and the frame; second means fixed to at least one of the frame and the second portions of the flexible member for emitting light in the direction of at least the other of the frame and the second portions of the flexible member; third means fixed to at least the other of the frame and the second portions of the flexible member to be separated from the second means by a distance dependent upon the variable length of the separation distance, the third means being responsive to the light emitted by the first means to provide an output signal and being responsive to the proximity of the second means to provide the output signal with characteristics dependent upon the magnitude of the muscle contractions in the abdominal wall of the mother; third portions included in the second portions and responsive to movement of the first means in response to a contraction of the muscles to move in a first direction with respect to the abdominal wall of the mother; fourth portions included in the second portions for carrying the first means, the fourth portions responsive to movement of the first means in response to a contraction of the muscles to move with respect to the abdominal wall in a second direction opposite to the first direction; whereby the first means carried by the fourth portions of the flexible member moves in a direction substantially perpendicular to the abdominal wall of the mother to maintain the area of contact between the first means and the abdominal wall substantially constant.

Claim 35

A contraction monitor for monitoring the contractions of muscles in the abdominal wall of a mother during labor, the monitor including: a frame having a substantially fixed relationship with the abdominal wall of the mother; a flexible member having first portions fixed with respect to the frame and second portions movable with respect to the frame to provide a separation distance between the flexible member and the frame, the separation distance having a length dependent upon the movement of the second portions of the flexible member relative to the frame; first means having a substantially fixed relationship with the flexible member and extending from the flexible member to the abdominal wall of the mother, the first means responsive to the contractions of the muscles in the abdominal wall to vary the length of the separation distance between the second portions of the flexible member and the frame; second means fixed to at least one of the frame and the second portions of the flexible member for emitting light in the direction of at least the other of the frame and the second portions of the flexible member; third means fixed to at least the other of the frame and the second portions of the flexible member to be separated from the second means by a distance dependent upon the variable length of the separation distance, the third means being responsive to the light emitted by the first means to provide an output signal and being responsive to the proximity of the second means to provide the output signal with characteristics dependent upon the magnitude of the muscle contractions in the abdominal wall of the mother; third portions included in the second portions and responsive to movement of the first means in response to a contraction of the muscles to move in a first direction with respect to the abdominal wall of the mother; fourth portions included in the second portions for carrying the first means, the fourth portions responsive to movement of the first means in response to a contraction of the muscles to move with respect to the abdominal wall in a second direction opposite to the first direction; whereby the first means carried by the fourth portions of the flexible member moves in a direction substantially perpendicular to the abdominal wall of the mother to maintain the area of contact between the first means and the abdominal wall substantially constant.

Claim 36

A contraction monitor for monitoring the contractions of muscles in the abdominal wall of a mother during labor, the monitor including: a frame having a substantially fixed relationship with the abdominal wall of the mother; a flexible member having first portions fixed with respect to the frame and second portions movable with respect to the frame to provide a separation distance between the flexible member and the frame, the separation distance having a length dependent upon the movement of the second portions of the flexible member relative to the frame; first means having a substantially fixed relationship with the flexible member and extending from the flexible member to the abdominal wall of the mother, the first means responsive to the contractions of the muscles in the abdominal wall to vary the length of the separation distance between the secoNd portions of the flexible member and the frame; second means fixed to at least one of the frame and the second portions of the flexible member for emitting light in the direction of at least the other of the frame and the second portions of the flexible member; third means fixed to at least the other of the frame and the second portions of the flexible member to be separated from the second means by a distance dependent upon the variable length of the separation distance, the third means being responsive to the light emitted by the first means to provide an output signal and being responsive to the proximity of the second means to provide the output signal with characteristics dependent upon the magnitude of the muscle contractions in the abdominal wall of the mother; and the first means includes a button mounted on the flexible member, the button having a convex surface constructed to contact the abdominal wall of the mother.

Claim 37

A contraction monitor for monitoring the contractions of muscles in the abdominal wall of a mother during labor, the monitor including: a frame having a substantially fixed relationship with the abdominal wall of the mother; a flexible member having first portions fixed with respect to the frame and second portions movable with respect to the frame to provide a separation distance between the flexible member and the frame, the separation distance having a length dependent upon the movement of the second portions of the flexible member relative to the frame; first means having a substantially fixed relationship with the flexible member and extending from the flexible member to the abdominal wall of the mother, the first means responsive to the contractions of the muscles in the abdominal wall to vary the length of the separation distance between the secoNd portions of the flexible member and the frame; second means fixed to at least one of the frame and the second portions of the flexible member for emitting light in the direction of at least the other of the frame and the second portions of the flexible member; third means fixed to at least the other of the frame and the second portions of the flexible member to be separated from the second means by a distance dependent upon the variable length of the separation distance, the third means being responsive to the light emitted by the first means to provide an output signal and being responsive to the proximity of the second means to provide the output signal with characteristics dependent upon the magnitude of the muscle contractions in the abdominal wall of the mother; and the first means includes a button mounted on the flexible member, the button having a convex surface constructed to contact the abdominal wall of the mother.

Claim 38

The contraction monitor recited in claim 28 wherein the third positions of the flexible member are movable with respect to the frame and the fourth positions of the flexible member move relative to the third portions of the flexible member.