Abstract: A decision support tool is provided for predicting uterine contractions. The predicted contractions are determined from measurements of uterine activity (UA). The contraction forecast may be made using a plurality of trained predictive models. The forecasts are formed with linear regressive models based, at least in part, on UA data from a reference population. The predicted contractions may be predictions of contraction duration, contraction peak, and time between contractions. In this way, these predicted contractions may be used for decision support for care plans during labor, such as increased monitoring and/or modifying the care plan.

Abstract: Embodiments of a system and method for heart rate monitoring are generally described herein. A method may include receiving, at a device, a spectrogram including a plurality of bins of represented frequencies corresponding to potential heart rate measurements, selecting a bin of frequencies from the plurality of bins of represented frequencies with an average power that exceeds average powers of remaining bins of frequencies of the plurality of bins of represented frequencies, determining whether a frequency of the bin of frequencies represents a valid heart rate based on the average power and a past valid heart rate, and in response to determining that the frequency represents a valid heart rate, outputting a heart rate corresponding to the frequency.

Abstract: An apparatus includes a processing assembly, a plurality of field generators, and a patient tracking assembly. The patient tracking assembly includes a sensor assembly and a communication assembly. The sensor assembly includes a first body, a first sensor, and an electrical conduit. The first body selectively attaches to a patient. The first sensor is mounted to the first body and generates a signal in response to movement within an electromagnetic field. The communication assembly includes a second body and a cable. The second body rotates relative to the first body from a first rotational position to a second rotational position. The cable extends away from the second body. The cable communicates with the processing assembly. The electrical conduit couples the first sensor with the cable while the casing is in the first rotational position and the second rotational position.

Abstract: Described herein are systems and methods for contraction monitoring. For example, a system for contraction monitoring includes an electrode patch including at least two electrodes, and a sensor module configured to be connected to the electrode patch. In some embodiments, the sensor module includes a signal acquisition module, a signal processing module, a power management module, a sensor control module, and a memory module and/or a data transmission module. In some embodiments, a method for contraction monitoring includes measuring, using the signal acquisition module, bio-potential signals by providing at least two electrodes on the abdomen of a pregnant woman.

Abstract: Provided herein is a self-contained physiological measuring device adapted for disposition within a patient body cavity, primarily the vagina, for an extended period of time (e.g., 6-48 hours or more). While disposed within the body cavity, the device periodically measures one or more physiological parameters at known locations within the body cavity. In addition to measuring such physiological parameters, the device is operative to store such measurements to memory for subsequent download/processing upon removal of the device from the body cavity and/or upon wireless interrogation.

Abstract: Aspects of an apparatus and method for detecting movement of an object includes a base and a projection member extending between a first second ends, wherein the first end is attached to the base. Further included is a support member at the second end of the projection member, and a guide wire carried by the support member and having a substantially fixed length, wherein the guide wire is movable between a first position and a second position in conjunction with movement of an object. Also included is a sensor located a substantially fixed distance along a path of the guide wire from the support member, wherein the sensor detects movement of the guide wire between the first second positions. Additionally included is a feedback unit in communication with the sensor, wherein the feedback unit is configured to generate feedback corresponding to the detected movement.

Abstract: A system is disclosed for long term, continuous, monitoring of pregnant mammals particularly to detect the onset of preterm labor. For example, the system enables communication between sensors and a collection unit for transmittal to a remote unit for display and monitoring of the collected data by a clinician while the individual is ambulatory and not in the presence of the clinician.

Abstract: A user wearable portable communication device and a method for collecting and transmitting a plurality of physiological parameters to a remote monitoring center are disclosed. The portable communication device includes a provision for enabling the user to establish a video conference, a fall detection module in conjunction with an accelerometer recognizes a placement of the portable communication device, a home automation module for enabling the user to remotely operate multiple electronic devices, an acknowledgment acceptance module for receiving the acknowledgment, a physiological data collecting module communicatively coupled to a fetal doppler module for monitoring and transmitting the physiological parameters associated with a child, multiple preprogrammed contact numbers for enabling the user to establish a communication, a subscriber identity module for enabling the user establish a communication and data transmission between the portable communication device and the remote monitoring center.

Abstract: A system and method of acquiring and transmitting uterine EMG signals is disclosed, where a signal processing module processes incoming uterine EMG signals from a patient and wirelessly transmits a processed signal to an information relaying device. The information relaying device is then configured to download the processed signal and transmit the signal to a call center or health care facility for physician evaluation. The system is ambulatory, thus allowing the patient to record and transmit uterine EMG signals anywhere a satisfactory transmission may be made. Additionally, a system and method of using electromyography for monitoring and diagnosis of uterine rupturing is disclosed, where incoming electrical signals from the lower uterine segment muscle fibers demonstrate an attenuated signal as the lower uterine segment thins and separates during the dilatation and effacement process of labor identifying those patients at increased risk for rupture.

Abstract: Various types of intravaginal monitoring devices (IMD) along with various supporting medical and computing devices within a communication network service pluralities of femal reproductive systems An IMD alone or with assistance from one or more supporting systems assists in detection, monitoring, therapy delivery and efficacy evaluations of various types of physiologic conditions of the various femal reproductive systems Exemplary conditions include those related to pregnancy, premature birth, fertility, ovulation, diseases, infections, fluids, flora, pre-cancerous conditions, cancer, non-human animal estrus, etc Various types of IMDs include those with multiple sensors within a housing sized for at least partial insertion into a vaginal channel of a reproductive system In some IMDs, only a single sensor such as an optical imager might be found, while in others multiple such imagers and as temperature, pH, glucose, electrolyte, sonogram, magnetic resonance, pressure, ultrasound, microphone, etc, sensors can a

Abstract: The present invention relates to systems and methods for providing a short-acting analgesic agent in the management of pain during labor, wherein the system enables efficient, real-time prediction of contractions for the coordinated administration of analgesia such that the peak effectiveness of the analgesic coincides with the intermittent pain of labor.

Abstract: Featured are apparatuses for measuring bioimpendence of tissues of the cervix, more specifically the mammalian cervix. Also featured are methods for examining the tissues of the cervix for clinical or diagnostic purposes such as during routine gynecological examinations to determine early onset of labor in pregnant patients or to assess such tissues for the presence of abnormalities such as cancerous lesions in both pregnant and non-pregnant women. Also featured are methods for treating onset of early or pre-term labor that embody such devices, apparatuses and methods of the present invention. Also featured are systems embodying such devices, apparatuses and/or methods, where such systems preferably are configured to provide diagnostic and/or clinical information to further assist the diagnostician or clinician in diagnosing and/or examining pregnant or non-pregnant patients.

Abstract: A method wherein a location or position sensor cooperates with a controller or other operating system such that a predefined motion pattern (circular motion, double click, translatory motion, reciprocal motion, and the like, and any combination thereof) of the sensor performs one or more specific tasks, which are not necessary related to the spatial locations per se of the sensor. Also a method for identifying sensors and landmarks is described including sensing the present location of the sensor plus an additional point and comparing with locations in the recent past.

Abstract: The bio-informatics system of the present invention serves to identify by electronic means, in body fluids of domestic and/or wild mammals, the metabolic changes that occur in each of the physiological moments of economic, scientific, and technological importance, associated with the female reproduction and with the health of animals in general. The system encrypts the information, analyzes it, memorizes when each one of the metabolic variables reach a predetermined level, and informs a receiver of the event.

Abstract: Disclosed is an apparatus for providing a visual image timed to coincide with uterine contractions to assist a expectant mother during childbirth labor. The apparatus is particularly useful directed to help those expectant mothers using a regional anesthesia, such as an epidural anesthesia, in the second stage of labor to push effectively. The apparatus consists of a computer system that converts signals obtained from strategically positioned sensors such as a tocodynamometer or intrauterine pressure catheter into biofeedback visual vignettes that are understandable to the expectant mother. The signals are processed into the visual vignettes or a similar pictorial image based upon the pressure of the uterine contractions so that the expectant mother may understand her contraction pattern. This in turn will allow the expectant mother to visually understand when to start and stop pushing during the second stage of labor.

Abstract: The present invention relates to systems and methods for providing a short-acting analgesic agent in the management of pain during labor, wherein the system enables efficient, real-time prediction of contractions for the coordinated administration of analgesia such that the peak effectiveness of the analgesic coincides with the intermittent pain of labor.

Abstract: An electrode interface system for providing a connection between at least one electrode and a maternal-fetal monitor, wherein the interface system converts electrical muscle activity captured by the electrode(s) into uterine activity data signals for use by the maternal-fetal monitor. The electrode interface system of the invention preferably includes a conversion means for converting the signals from the electrode(s) into signals similar to those produced by a tocodynometer.

Abstract: An improved patient monitoring system is described herein. In particular, the present invention provides an improved system, method, and kit for positioning and removably mounting, often repeatedly, a monitor transducer on a patient, for example, an external fetal monitor used during pregnancy and childbirth labor. The improved system of the present invention avoids many of the disadvantages of conventional monitoring systems in that it maintains transducer position during patient movement, allows the position of the transducer to be changed without repositioning the patient, allows for simple and expeditious adjustment so as to maximize signal quality without causing patient discomfort, eliminates the need for a belt circumferentially disposed about the patient's abdomen, and can be applied to a wide array of body types, including patients having round abdomens. The system, method, and kit of the present invention is not only both efficient and effective but also economical.

Abstract: A system and method are provided for transducing vaginal conditions, affecting vaginal or body conditions, and/or stimulating perineal musculature and nerves. A separate, portable, non-implanted intravaginally containable combination probe and transceiver is provided that can sense vaginal conditions, can deliver signals or medication, and/or can stimulate perineal musculature and nerves. This probe unit is provided with 2-way wireless communication for transmitting information that is transduced and for receiving control and programming signals. In addition, a separate combination controller and transceiver is provided for wirelessly sending signals to the probe unit and for receiving signals therefrom. A real time wireless signal feedback loop is thus provided between the controller and the probe and/or external devices, networks and databases.

Abstract: A method and apparatus for the transcutaneous monitoring of blood gases generally comprises a blood gas data acquisition device, a vacuum source and a blood gas transducer unit. The blood gas transducer unit is adapted for application to a patient's skin and administration of a local vacuum at the area of patient application. It further comprises an electrochemical blood gas transducer, well known to those of ordinary skill in the art, which is disposed entirely within the local vacuum at the area of patient application. The vacuum source is placed in fluid communication with the blood gas transducer unit, through a hydrophobic membrane filter for safety purposes, in order to induce a condition of hyperperfusion in the locality of the electrochemical blood gas transducer. Under the control of a microcontroller, or equivalent means, the blood gas acquisition device is then utilized to capture a measure of skin surface oxygen or carbon dioxide pressure.

Abstract: A birth monitoring system (100), comprising a monitor (120) including at least one sensor operative to measure a physiological parameter associated with labor; a posture sensor (130) which generates a signal indicative of posture of a mother (110); and circuitry which generates an output signal dependent on both a measurement of said sensor and a posture measurement of said posture sensor (130).

Abstract: Apparatus for controlling the childbirth labor comprising an electromyographic unit (4) with sensors (3) for detecting electrical signals of a parturient's uterus and means (6) for analyzing and processing the electrical signals, and a pneumatic belt (1) to be fixed around the parturient's abdomen having sensors (15) to detect the variation of the internal pressure due to uterine contractions, and means (2) for inflating the belt to provide a thrust as an aid for the expulsion of the fetus, where a device (7) is provided, associated with sensors (15) and (3) to control the activation of means (2) for the inflation of the pneumatic belt (1).

Abstract: A beltless fiber optic labor contraction sensing device including a fiber optic strain sensor for detecting labor contractions during childbirth. The fiber optic strain sensor includes an optic cable, a light source for transmitting a light beam through the optic cable and a light detector for identifying changes in the optical signal. The fiber optic strain sensor is operable to generate an appropriate response to any changes in the optical signal that are caused by the application of force against the fiber optic cable. An adhesive pad or sensor jacket is provided to secure the fiber optic strain sensor to the mother's abdomen without the use of a belt or strap. The contraction device includes wireless communication for transmitting an output signal to a standard contraction recording device. Further, one or more of the components of the labor contraction sensing device are fabricated so as to be disposable.

Abstract: The invention relates to a device for producing measuring data relating to the movements of the abdominal wall of a person, comprising at least one first pair of sensor units which are configured for detachably fixing to the skin on an abdominal area of a person, a first distance apart; and a measuring device which is connected to said first pair of sensor units and which is configured for picking up signals of the sensor units that can be evaluated electrically and for producing a first distance signal corresponding to the first distance and to changes thereto. An evaluating unit is connected downstream of said measuring device.

Abstract: A medical transponder, including an ultrasonic sensor that detects impinging ultrasonic waves and generates electrical signals in response thereto; an electrical connection which receives said signals; and an electromagnetic RF transmitter coupled to said electrical connection and which generates an RF signal in response to said detected waves.

Abstract: A device for prediction of onset of labor comprises a portable assembly of a plurality of recording electrodes (3) and optionally a reference electrode (4), a means for data acquisition (1), a means for conversion of analogue to digitized data and a display (5) adapted to display this data in terms of one of a small number of discrete results indicative of the state of preparedness for labor, wherein each electrode (3) comprises a contact surface for application to a subject, and in particular to an abdominal and/or vaginal surface of a subject, the device further comprising data analyzing means (1) for analyzing the digitized data with reference to pre-recorded reference data and/or predetermined reference parameters.

Abstract: The present invention presents a method and apparatus for recording and analyzing uterine electrical activity, or electromyography (EMG), from the surface of the abdomen, vagina, or cervix of a patient for the purpose of diagnosing contractile patterns of the uterus in pregnant and non-pregnant women, as well as for monitoring maternal and fetal ECG and fetal brain activity. The method and apparatus described include methods for the systematic detection, analysis, characterization and communication of information about electrical signals recorded from the abdominal/vaginal/cervical surface. The present invention provides data analysis techniques for analyzing the electrical data measured from the surface of a patient to characterize their uterine, abdominal, and cardiac muscle activity, as well as cardiac and brain activity of the fetus simultaneously or separately.

Abstract: A handheld childbirth labor timing apparatus includes a timing device with a visible display, a calculating device, a memory device and a selection device. In various embodiments the apparatus is programmed to execute methods for the simple timing of the durations of and intervals between actual childbirth contractions, for practicing selected sequences of such contractions in preparing for childbirth, and also for storing a set of expected sequences that, when matched, with an actual childbirth labor sequence will present an alerting signal to the user so as to timely summon medical help.

Abstract: An integrated function appliance to assist the process of child birth by providing convenient timing of labor contractions, to calculate contraction event parameters, to compare contraction parameter values to pre-defined values and alert the user to the probable immediacy of birth based upon the comparison, to provide pain management assistance with a visual focus object which may be synchronized to contraction events, to provide pain management assistance with an ergonomically fashioned handle suitable for vigorous labor pain response squeezing. The invention may use a single variable capacitance actuated control input means. The invention is ergonomically designed to be is non-intrusive in the stressful context of the labor process.

Abstract: A method and apparatus for controlling uterine contractions in a female comprises providing sensors for sensing uterine contractions; providing an electric signal generator for generating signals to be applied on the uterus; providing a control unit for receiving signal corresponding to uterus contractions from the sensors and actuate said signal generator to generate a non-excitatory electric signal in a predetermined timing and duration with respect to a sensed uterine contraction; providing signal delivery leads for delivering the electric signal from the electric signal generator to predetermined locations on the uterus; sensing a uterine contraction using the sensors; and applying non-excitatory electric field at the predetermined locations on the uterus in predetermined timing and duration with respect to the sensed uterine contraction.

Abstract: The invention relates to a device for producing measuring data relating to the movements of the abdominal wall of a person, comprising at least one first pair of sensor units which are configured for detachably fixing to the skin on an abdominal area of a person, a first distance apart; and a measuring device which is connected to said first pair of sensor units and which is configured for picking up signals of the sensor units that can be evaluated electrically and for producing a first distance signal corresponding to the first distance and to changes thereto. An evaluating unit is connected downstream of said measuring device.

Abstract: A beltless fiber optic labor contraction sensing device including a fiber optic strain sensor for detecting labor contractions during childbirth. The fiber optic strain sensor includes an optic cable, a light source for transmitting a light beam through the optic cable and a light detector for identifying changes in the optical signal. The fiber optic strain sensor is operable to generate an appropriate response to any changes in the optical signal that are caused by the application of force against the fiber optic cable. An adhesive pad or sensor jacket is provided to secure the fiber optic strain sensor to the mother's abdomen without the use of a belt or strap. The contraction device includes wireless communication for transmitting an output signal to a standard contraction recording device. Further, one or more of the components of the labor contraction sensing device are fabricated so as to be disposable.

Abstract: The present invention relates to telemetry-based sensing systems that continuously measures physical, chemical and biological parameters. More specifically, these sensing systems comprise a small, modular, low-power implantable biotelemetry system capable of continuously sensing physiological characteristics using implantable transmitters, a receiver, and a data acquisition system to analyze and record the transmitted signal over several months. The preferred embodiment is a preterm labor and fetal monitoring system. Key features of the invention include Pulse Interval Modulation (PIM) that is used to send temperature and pressure information out of the biological environment. The RF carrier frequency is 174-216 MHz and a pair of RF bursts (pulses) is transmitted at a frequency of about 1-2 Hz. The transmission range is 3 to 10 feet, depending on the position of the transmitter in the body and its biological environment. The entire transmitter is encapsulated in biocompatible silicone rubber.

Abstract: The present invention presents a method and apparatus for recording and analyzing uterine electrical activity, or electromyography (EMG), from the surface of the abdomen, vagina, or cervix of a patient for the purpose of diagnosing contractile patterns of the uterus in pregnant and non-pregnant women, as well as for monitoring maternal and fetal ECG and fetal brain activity. The method and apparatus described include methods for the systematic detection, analysis, characterization and communication of information about electrical signals recorded from the abdominal/vaginal/cervical surface. The present invention provides data analysis techniques for analyzing the electrical data measured from the surface of a patient to characterize their uterine, abdominal, and cardiac muscle activity, as well as cardiac and brain activity of the fetus simultaneously or separately.

Abstract: An apparatus for automatically measuring a blood pressure of a female subject, including a blood-pressure measuring device which includes an inflatable cuff adapted to apply a pressing force to a body portion of the subject and automatically measures, by changing the pressing force of the cuff, a blood pressure of the female subject at a predetermined measurement period, a labor-pain-signal detecting device which detects, from the female subject, a labor-pain signal which changes in relation to a labor pain of the subject, and a blood-pressure-measurement starting device for operating the blood-pressure measuring device to start a blood-pressure measurement, when the predetermined measurement period has elapsed and when the labor-pain signal detected by the labor-pain-signal detecting device falls within a reference range.

Abstract: A device for implantation on the cervix of a pregnant female that provides monitoring means by which the dilatation of a female patient's cervix may be monitored during the first phase of labor. The device comprises a housing manufactured from biocompatible material into which a spindle member joined to a tension sensor passes. The housing also contains a transmitter and a power source for the sensor and transmitter. A plurality of sutures are fixed the spindle and pass out of housing so that they may be attached to the female patient's cervix. A tension knob is provided for winding excess suture length onto the spindle, thereby securing the device within the vagina. Dilatation of the cervix at the onset of labor exerts tension on the sutures which is conveyed to the spindle and translated by the sensor to a signal directed at the transmitter.

Abstract: Systems and methods for medical diagnosis or risk assessment for a patient are provided. These systems and methods are designed to be employed at the point of care, such as in emergency rooms and operating rooms, or in any situation in which a rapid and accurate result is desired. The systems and methods process patient data, particularly data from point of care diagnostic tests or assays, including immunoassays, electrocardiograms, X-rays and other such tests, and provide an indication of a medical condition or risk or absence thereof. The systems include an instrument for reading or evaluating the test data and software for converting the data into diagnostic or risk assessment information.

Abstract: A device for implantation on the cervix of a pregnant female that provides an alerting means by which a female patient or her health caregiver is notified of the onset of labor. The device comprises a housing manufactured from biocompatible material into which a spindle member joined to a tension sensor passes. The housing also contains a transmitter and a power source for the sensor and transmitter. A plurality of sutures are fixed the spindle and pass out of housing so that they may be attached to the female patient's cervix. A tension knob is provided for winding excess suture length onto the spindle, thereby securing the device within the vagina. Dilatation of the cervix at the onset of labor exerts tension on the sutures which is conveyed to the spindle and translated by the sensor to a signal directed at the transmitter. The transmitter issues an electronic signal to a second electronic device such as a pager or PDA, notifying the patient or her health caregiver of impending birth.

Abstract: A device for implantation on the cervix of a pregnant female that provides a means by which a female patient or her health caregiver is notified of the rupture of membranes by the release of amniotic fluid. The device comprises a housing manufactured from biocompatible material having a hole through which amniotic fluid in the patient's vagina may pass. The housing contains a pH meter and a transmitter in electronic communication therewith as well as a power source for the sensor and transmitter. When amniotic fluid is released through the cervix into the vagina, a quantity thereof may pass into the housing and sensed by the sensor, causing the sensor to direct a signal to the transmitter. The transmitter issues an electronic signal to a second electronic device such as a pager or PDA, notifying the patient or her health caregiver that her water has broken.

Abstract: Systems and methods for medical diagnosis or risk assessment for a patient are provided. These systems and methods are designed to be employed at the point of care, such as in emergency rooms and operating rooms, or in any situation in which a rapid and accurate result is desired. The systems and methods process patient data, particularly data from point of care diagnostic tests or assays, including immunoassays, electrocardiograms, X-rays and other such tests, and provide an indication of a medical condition or risk or absence thereof. The systems include an instrument for reading or evaluating the test data and software for converting the data into diagnostic or risk assessment information.

Abstract: A fetal health assessor and outcome predictor and monitoring system includes a system for automatically assessing fetal health and predicting fetal outcomes based on fetal and maternal data. The system includes a case-based reasoning processor for categorizing the fetus into one of a plurality of cases based on biographical data about the fetus and mother. The system also includes a transducer for converting physical conditions of the fetus and mother (e.g. characteristics based on heart rates and uterine contractions) to signals representative of the conditions. A computer processor converts the signals to a set of signal features. An assessor and predictor receives the processed signal features and assesses fetal health and predicts fetal outcome based on identified fuzzy relationships between fetal and maternal data and fetal outcomes.

Abstract: A method and system for receiving, processing and responding to emergency medical calls for patients with pregnancy related medical problems is described. A consistent, standard and systematic process is provided which in combination with adequate training, supervision and quality assurance serves to provide a method for gathering emergency medical information regarding a patients pregnancy problems, categorizing such information into various determinant levels for appropriate response, and for giving qualified emergency medical information to callers thereby permitting "zero time" response by those at the scene. By using this invention properly a dispatcher is guided through the interrogation of callers concerned with pregnancy, childbirth or miscarriage medical problems, gathering critical information and giving the appropriate guidance to the caller.

Abstract: Novel methods for delivering a drug to a patient while preventing the exposure of a foetus or other contraindicated individual to the drug. Embodiments are provided in which the involved prescribers, pharmacies and patients are registered in one or more computer databases. Embodiments are also provided in which registered patients receive counseling information concerning the risks attendant to foetal exposure to the drug. Male patients and female patients who are not pregnant may, in certain circumstances, receive the drug.

Abstract: A fetal movement recorder instrument for registering perceived fetal movement includes an actuator operated by the maternal patient to indicate a perceived fetal movement by the maternal patient, the relative intensity, date, and time, so as to provide a corresponding actuator output signal. A data log unit receives and records the perceived fetal movement information over a preset counting period. A start/stop count alarm provides a stop count indication when the preset counting period is over, and a display provides a message corresponding to the number of fetal movement counts over a predetermined time. The recorded information is transmitted from the data log/base station to the care provider's location where feedback information may be transmitted back to the base station at the maternal patient location.

Abstract: The childbirth process is monitored by applying one or more probes to the mother and monitoring the locations of the probes by transmitting non-ionizing fields such as magnetic fields between the probes and reference elements in proximity to the mother. The magnitude and direction of movement of the probes indicates the magnitude and direction of uterine contractions. Fetal position and cervical dilation may be monitored by providing additional probes attached to the fetus and to the cervix.

Abstract: A multipurpose pregnancy and labor timing device for use by expectant parents during the gestation, labor, and birth of their child. The timing device includes an output device for conveying a plurality of datum to a human ovserver. The datum conveyed may represent a current time, day and date, an expected date of birth of the child, an estimated elapsed time period since the conception date of the child, an estimated time period until the birth of the child, the count of contractions experienced by a woman undergoing the process of labor, the time interval between contractions, the duration of a contraction, and the actual time and date of the birth of the child. The timing device also includes a nonvolatile memory for storing at least some of the plurality of datum, a data selection device for selecting at least some of the plurality of datum for conveyance by the output device, and a data initialization device for initializing the first datum and the second datum.

Abstract: A pair of components for an instrument for determining the female fertile period by measuring the viscoelasticity of saliva that includes a pair of strata composed of a rigid material, preferably glass or a polymer, and a surface on each strata, where the surface has a random distribution of peaks and valleys, the average depth from the peaks to the valleys is in the range of from about 10 picometers to about 100 micrometers, and the total area of the valley walls below one half of the average depth is from 35% to 65% of the total area of the surface. Preferably, the average depth of the valleys is in the range of 50 micrometers to 80 micrometers and the total area of the valleys below one half of the average depth is between 45% and 55% of the total area of the surface.