The present invention relates generally to the field of obstetrics and, more specifically, to a method and apparatus for monitoring labor progression and for providing a user interface to display data conveying fetal and maternal information during labor.
Uterine contractions are intermittent and co-ordinated tightenings of the uterine muscle. Uterine contractions provide the force that makes labour progress, by causing the baby to descend through the birth canal and making the cervix efface (shorten), and dilate (open). This force is related to the frequency, strength and duration of the contractions. Oxytocin is a natural hormone that causes uterine contractions. A synthetic version of oxytocin is often administered during labour to increase the frequency, duration and strength of uterine contractions or to induce labour. The medication is administered through a continuous intravenous infusion. There is no fixed dosage as in antibiotic therapy; rather the dose is adjusted frequently according to the patient's response to achieve the desired frequency and intensity of contractions.
When the uterine muscle contracts, the maternal blood vessels in it are constricted causing a temporary reduction in the blood flow and delivery of oxygen to the baby's placenta. Relaxation of the contraction restores the flow and oxygen delivery to the baby. In normal circumstances, babies tolerate contractions well. However, in other circumstances, such as when the placenta malfunctions or the contractions are excessively frequent with little or no relaxation time between them, the baby may not tolerate this reduction in oxygen delivery. If the situation remains uncorrected or worsens it may result in injury to the baby's brain and permanent disability.
At present, clinical staff estimates the frequency of contractions by feeling the mother's abdomen for a few minutes and noting the timing of a few contractions or by examining a paper tracing that shows a recording of contraction pressures/intensity over time. These assessments are performed periodically and the results recorded in the medical record.
A deficiency with the above-described methods for assessing contraction frequency is that they are prone to inaccuracy and incompleteness because they are visual estimates based on short selected segments of the tracing. Labour can last many hours. Fatigue, distraction and inexperience of the clinical staff can contribute to variable operator response. Frequent false alarms breed disregard. As a result, the caregiver may fail to make assessments at the prescribed time intervals and may fail to appreciate the degree and duration of the abnormality as well as the response of the baby. Thus, there can be a delay or failure to recognize overly frequent contractions, to adjust the medication correctly, resulting in an iatrogenic injury to the baby.
In the context of the above, there is a need to provide a method and device for monitoring contractions for an obstetrics patient that alleviates at least in part problems associated with the existing methods and devices.
In accordance with a first broad aspect, the invention provides a method for displaying uterine contraction information. The method comprises receiving a contraction signal conveying information related to occurrences of uterine contractions over time and processing the contraction signal to derive a sequence of contraction persistence indices. Each contraction persistence index in the sequence is associated to a portion of the contraction signal and conveys whether there is an excess in the rate of contraction in the associated portion of the contraction signal. In cases where there is an excess in the rate of contraction in the associated portion of the contraction signal, the contraction persistence index conveys whether or not this excess is part of a sustained pattern of excess in the rate of contractions. The method also comprises causing the sequence of contraction persistence indices to be conveyed to a user on a display device.
In accordance with a specific example of implementation, each contraction persistence index in the sequence of contraction indices is derived at least in part based on:
In accordance with a specific example of implementation, the method also comprises causing an alarm event based at least in part on at least one contraction persistence index in the sequence of contraction persistence indices.
An advantage of the present invention is that it allows clinical staff to readily distinguish between short-term variations and/or excesses in the contraction rate and long term persistence of excess in the contraction rate. While short-term variations and/or excesses in the contraction rate could signal innocuous transient states, the clinical staff has a medical responsibility to review and possibly intervene such as by altering medication use or other suitable types of intervention in the case of long term persistence of excesses in the contraction rate is identified.
In accordance with another broad aspect, the invention provides an apparatus for displaying uterine contraction information in accordance with the above-described method.
In accordance with another broad aspect, the invention provides a computer readable storage medium storing a program element suitable for execution by a CPU, the program element implementing a graphical user interface module for displaying uterine contraction information. The graphical user interface module is adapted for displaying uterine contraction information in accordance with the above-described method.
In accordance with another broad aspect, the invention provides a labour monitoring system. The system includes a sensor for receiving information indicative of occurrences of uterine contractions over time. The system also includes an apparatus for implementing a user interface for displaying uterine contraction information in accordance with the above-described method. The system also includes a display unit in communication with the apparatus. The display unit is responsive to a signal releasing by the output of the apparatus to display the graphical user interface.
In accordance with yet another broad aspect, the invention provides a server system implementing a graphical user interface module for displaying uterine contraction information. The server system stores a program element for execution by a CPU. The program element includes a plurality of program element components. A first program element component is for receiving contraction signals conveying information related to occurrences of uterine contractions over time. A second program element component is for processing the contraction signal to derive a sequence of contraction persistence indices. Each contraction persistence index in the sequence is associated to a portion of the contraction signal and conveys whether there is an excess in the rate of contraction in the associated portion of the contraction signal. If there is an excess in the rate of contraction in the associated portion of the contraction signal, the contraction persistence index also indicates whether this excess is part of a sustained pattern of excess in the rate of contractions. A third program element component for generating and issuing a signal for displaying a graphical representation of the sequence of contraction persistence indices.
In accordance with yet another broad aspect, the invention provides a client-server system for implementing a graphical user interface module for displaying uterine contraction information. The client-server system comprises a client system and a server system operative to exchange messages over a data network. The server system stores a program element for execution by a CPU. The program element includes a plurality of program element components. A first program element component is for execution on the server system and is for receiving a contraction signal conveying information related to occurrences of uterine contractions over time. A second program element component is for execution on the server system and is for processing the contraction signal to derive a sequence of contraction persistence indices. Each contraction persistence index in the sequence is associated to a portion of the contraction signal and conveys whether there is an excess in the rate of contraction in the associated portion of the contraction signal. If there is an excess in the rate of contraction in the associated portion of the contraction signal, the contraction persistence index also indicates whether this excess is part of a sustained pattern of excess in the rate of contractions. The third program element component is to be executed on the server system and is for sending messages to the client system for causing the client system to display a graphical representation of the sequence of contraction persistence indices.
In a specific implementation, the client-server system includes a plurality of client systems operative to exchange messages with the server system over a data network. The data network may be of any suitable network configuration including Intranets and the Internet. The client systems may be embodied in any suitable computing device including, but not limited to, desktop computers, laptop computers and personal digital assistants (PDAs).
These and other aspects and features of the present invention will now become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying drawings.
In the accompanying drawings:
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
With reference to
In accordance with a specific implementation, the sensor 120 for monitoring uterine activity samples the contraction pattern at a certain pre-determined frequency to generate a signal indicative of uterine activity. The resulting signal, herein referred to as a contraction signal, conveys information related to the occurrence of uterine contractions over time. More specifically, the contraction signal conveys information on the occurrence of contraction events. Broadly stated, a contraction event refers to a continuous time period during which the uterine muscle of an obstetrics patient is tightening. During labour, contraction events are interleaved with relaxation periods during which the uterine muscle ceases to contract or contracts to a lesser extent. The contraction signal may be a continuous signal conveying contraction intensity information or may be comprised of unitary signal events where a signal event is generated when a contraction event is detected. Typically, when the contraction signal is comprised of unitary signal events, a signal event is generated when the onset of a contraction event is detected. Such sensors may be based on pressure or electrical signals from the abdominal wall, or within the uterine cavity. Sensors for monitoring uterine activity are well known in the art to which this invention pertains and any suitable sensor may be used without detracting from the spirit of the invention and as such will not be described further here.
Alternatively, certain embodiments of the labour monitoring system 150 may omit the sensor 120 and instead make use of a user-controlled input for generating the contraction signal. The user-controlled input allows a user to provide over time information signalling the onset of a contraction event such as to convey information associated to contraction activity over time. Such a user-controlled input may be in the form of a manually controlled actuator that can be activated by depressing a button when the obstetrics patient senses the onset of a contraction or in any other suitable configuration allowing a user to signal the onset of contraction events over time. Although the user controlling the actuator may be the expectant mother, it will most likely be a person other than the expectant mother, such as the expectant father or a nurse for example, since the expectant mother will most likely have other concerns during labour. In such an alternative embodiment, the contraction signal is comprised of unitary signal events. It will be readily appreciated that such a configuration may be somewhat inconvenient in practice since it would require that the user diligently enter contraction information. Consequently, although this alternative implementation has been presented for the purpose of completeness and as an alternative example of implementation, it will be readily appreciated that using a sensor 120 for monitoring uterine activity will be preferred in practical implementations of the invention.
The apparatus 100 is for implementing a graphical user interface module for displaying uterine contraction information. The contraction information may be displayed in various forms as will become apparent later on in the specification. Optionally, the graphical user interface module implemented by the apparatus 100 selectively causes an alarm event based at least in part on the uterine contraction information. The apparatus 100 also releases a signal for causing the display unit 114 to display the graphical user interface module. Optionally, the apparatus is further adapted for releasing signals to a data output module 130 for causing the latter to convey information related to maternal/fetal well-being and/or labour progression to a user of the labour monitoring system 150. Specific examples of implementation of the apparatus 100 and of the graphical user interface module will be described later on in the specification.
The user input device 118 is for receiving data from a user of the system. The user input device 118 may be used, for example, to enter information associated with the obstetrics patient and/or to manipulate the information displayed by the user interface implemented by the apparatus 100. Optionally still, the user input device 118 may be used to enter contraction medication information conveying information associated to administration of contraction inducing medication to the obstetrics patient. The contraction medication information may indicate whether contraction-inducing medication was administered and, optionally, the dosage of the contraction inducing medication that was administered. Since, typically, contraction-inducing medication is administered continuously over time and not as a one shot dose, the contraction medication information conveys the dosage of the contraction inducing medication administered over time. The user input device 118 may include any one or a combination of the following: keyboard, pointing device, touch sensitive surface, keypad or speech recognition unit. Certain embodiments of the labour monitoring system 150 may omit the user input device 118 without detracting from the spirit of the invention.
Optionally, as shown in
Optionally still, the labour monitoring system 150 may include other sensors (not shown) for measuring labour progress and the fetus' tolerance to labour. Such sensors may include for example:
Such sensors are not critical to the invention and therefore will not be described further here.
The display unit 114 is in communication with the apparatus 100 and receives a signal causing the display unit 114 to display a graphical user interface module implemented by apparatus 100. The display unit 114 may be in the form of a display screen, a printer or any other suitable device for conveying to the physician or other health care professional uterine contraction information associated to an obstetrics patient. In embodiments where the display unit 114 is in the form of a display screen, it may be part of any suitable type of apparatus including, without being limited to, a desktop/laptop computing apparatus, a personal digital assistant (PDA), a telephone equipped to video display capability, a TV monitor or any other suitable device equipped with a display screen for visually conveying information to a user.
Optionally, the labour monitoring system 150 may further include a data output module 130. The data output module 130 is in communication with the apparatus 100 and is suitable for receiving signals generated by the apparatus 100. In a first specific example of implementation, the data output module 130 includes an audio module for releasing audio signals on the basis of signals received from the apparatus 100. In a second specific example of implementation, the data output module 130 includes a data communication entity suitable for transmitting messages to remote devices causing the latter to convey to a user of the labour monitoring system 150 information related to maternal/fetal well-being and/or labour progression. Examples of remote devices include, without being limited to, PDAs, telephones, pagers and computing terminals.
A specific practical implementation of the labour monitoring system 150 may implement the graphical user interface module for displaying uterine contraction information as a stand-alone component or alternatively as part of a more complete labour monitoring system including a plurality of modules for monitoring various aspects of maternal/fetal well-being and/or labour progression. An example of such a labour monitoring system is described in co-pending U.S. patent application entitled “METHOD AND APPARATUS FOR DISPLAYING LABOUR RELATED INFORMATION ASSOCIATED TO AN OBSTETRICS PATIENT” filed on May 1, 2006 by Emily Hamilton and which was assigned Ser. No. 11/416,281, and was published on Nov. 1, 2007 under U.S. publication No. 20070255588A1. The contents of the above application are incorporated herein by reference.
A specific example of implementation of apparatus 100 will now be described with reference to
Optionally, the apparatus further includes an additional input (not shown in the figures) for receiving fetal heart rate information. The fetal heart rate information may including a fetal heart rate signal as generated by fetal heart rate sensor (110) or, alternatively, may include information conveying a level of risk associated with the fetus, the level of risk being derived on the basis of a fetal heart rate signal. Where the fetal heart rate information includes a fetal heart rate signal, the apparatus 100 is adapted for processing the signal to determine a level of risk associated with the fetal heart rate signal. Any suitable method for assessing a level of risk on the basis of a fetal heart rate signal may be used. For example, the level of risk may be based on the frequency of the fetal heart rate, whether it is too high or too low for a certain period of time. Alternatively, the level of risk may be based on other known methods. A non-limiting example of a method for providing an indication of the level of risk is described in U.S. Pat. No. 7,113,819, entitled “Method and apparatus for monitoring the condition of a fetus”, issued on Sep. 26, 2006 to E. Hamilton et al. and assigned to LMS Medical Systems Ltd. The contents of this document are incorporated herein by reference. Other suitable methods for assessing a level of risk on the basis of a fetal heart rate signal may be used without detracting from the spirit of the invention.
The graphical user interface module implemented by apparatus 100 will now be described in greater detail.
The graphical user interface module receives the contraction signal originating from input 202 and conveying information related to uterine contractions over time. The graphical user interface module processes the contraction signal to derive a sequence of contraction persistence indices. Each contraction persistence index conveys whether there is an excess in the rate of contractions in an associated portion of the contraction signal and whether this excess is part of a sustained pattern of excess in the rate of contractions. The graphical user interface module then conveys the sequence of contraction persistence indices to a user. Optionally, the graphical user interface module displays, concurrently with the contractility persistence index, information conveying rates of uterine contractions over time and/or information conveying a threshold rate of uterine contractions.
Generally stated, the contractility persistence index is an index intended to capture one or more characteristics of the contraction signal, in particular excesses in the rate of contractions and the duration of these excesses. In this manner, the contractility persistence index combines both contraction frequency and duration information into a same information element in order to provide the clinical staff with an indication of whether an excess in the rate of contraction is sustained or is merely transient.
In a specific example, the contractility persistence index assigned to time “n” is a function of the contraction rate at time “n” and of the contraction rate at one or more times preceding time “n”. Mathematically, a specific example of the contractility persistence index can be expressed as follow:
where Contractility Persistence Index [n] denotes the contractility persistence index at time “n”; contraction rate[n] denotes the rate of contraction at time “n”; contraction rate [n−ki] and contraction rate [n−km] denotes the rate of contraction at one or more times preceding time “n” and f( ) denotes a function. The above equation denotes the computation of the contractility persistence index as a value calculated at discrete instants in time over time. It will be readily appreciated that, in certain implementations, the contractility persistence index may be computed in a continuous fashion over time without detracting from the spirit of the invention.
The nature of function f( ) used for determining the contractility persistence index at a certain time may vary from one implementation to the other. The function f( ) may be a mathematical function or may simply denote a set of rules applied to determine the value of the contraction persistence index to assign at a given time.
For the purpose of illustration, specific examples of contraction persistence indices will now be described.
As a first practical example of implementation, the contractility persistence index at a time “n” is based on a weighted sum of the contraction rate at time “n” and of one or more contraction rate(s) at times preceding time “n”. Mathematically, a specific example of such a contractility persistence index can be expressed as follow:
where Weighted Sum[n] denotes the weighted sum of the contractions at time “n”; contraction rate[n] denotes the rate of contraction at time “n”; contraction rate [n−ki] for denotes the rate of contraction at one or more times preceding time “n”; w0 and wi are weight values assigned to the contraction rates measured at different times; the Contractility Persistence Index [n] denotes the contractility persistence index at time “n” and G( ) denotes a function. In a specific example, contraction rates at times further from time n are weighted less heavily than contraction rates at times closer to time n. In its simplest form, the G( ) is the identify function, in other words the weighted sum is itself the index. In another example, the function G( ) provides a mapping between different possible values of the weighted sum and a set of index levels. In another example, the function G( ) is an averaging function so that the contractility persistence index is a weighted average of the contraction rates over time.
Other embodiments of the contractility persistence index may take into account whether the contraction rate exceeds a threshold contraction rate. The threshold rate of uterine contractions defines boundaries of safe care and may be set in accordance best practices or in accordance with hospital/care-giver facility policy. Although most the present description will typically refer to a single threshold rate of uterine contraction, it will be readily apparent that embodiments including multiple thresholds of uterine contractions, each threshold being associated with a respective degree of risk to the obstetrics patient, may be used in alternative implementations of the present invention.
As a second practical example, the contractility persistence index includes four levels defined as follows:
Contractility persistence index [n]=
In the example above, the first and second predetermined time durations may be established on the basis of a hospital policy or, alternatively, on the basis of other clinical guidelines and may therefore vary from one implementation to the other. Although in the above example the contractility persistence index only includes four (4) levels, it will be readily apparent that specific implementations may include fewer or additional levels without detraction from the spirit of the invention. Other embodiments of the above contractility persistence index may make use of multiple threshold contraction rates and/or may take into account the degree or extent to which the contraction rate exceeds a threshold contraction rate.
Other embodiments of the contractility persistence index may take into account the degree or extent to which the contraction rate exceeds a threshold contraction rate. As a third specific example, such a contractility persistence index is presented below:
As will be appreciated by the reader skilled in the art, the above described examples of contractility persistence indices are only examples and many possible variants and alternatives are possible.
In particular, although the above described examples of contractility persistence indices have only considered factors related to the contraction signal, it will be appreciated that variants of the contractility persistence index may consider other labour related progress in addition to the contraction signal. Example of other factors that may be considered in the contractility persistence index include, without being limited to, fetal heart rate (FHR) abnormalities and the level of uterotonic medication (such as oxytocin) administered to the obstetrics patient.
In a specific example of implementation, the contractility persistence index value is derived for each time segment of duration T and is displayed in graphical format. In a non-limiting example of implementation, the duration T of the time segment is 2 minutes.
The specific manner in which the information related to the contractility persistence index can be displayed to a user of the system 150 by the graphical user interface module may vary from one implementation to the other without detracting from the spirit of the invention.
Specific non-limiting examples of implementation of a graphical user interface module are shown in
A first specific example of implementation of the graphical user interface module is shown in
In this specific implementation, the value of the contractility persistence index is displayed as a function of time (time is shown in the horizontal axis). In the example shown in
Advantageously, the implementation depicted in
A second specific example of implementation of the graphical user interface module is shown in
In
Advantageously, in situations where the current contraction rate exceeds the boundaries of safe care as conveyed by the second alphanumeric element 603, the third alphanumeric element 604a, which reflects the current value of the contractility persistence index, provides an indicating of whether this excess is transitory and therefore not critical or sustained and potentially requiring intervention.
Optionally, as depicted in the specific examples shown in
The graphical user interface module is adapted for selectively causing an alarm event based at least in part on the contractility persistence index. In a specific example of implementation, the alarm event is for alerting the clinical staff making use of the system of an occurrence of a potentially problematic situation during labour associated to the occurrence of contractions. The alarm event may be triggered in a number of situations and may be based on the contractility persistence index and optionally on the basis of either one or both of contraction medication information and fetal heart rate information. Examples of the manners in which an alarm event may be selectively caused will be described later on in the specification.
An alarm event, in accordance with a specific example of implementation of the invention, may include one or more components for communicating information to a user of the graphical user interface module.
In a first specific implementation, the alarm event includes displaying a visual indicator to convey to a user of the graphical user interface module an occurrence of a potentially problematic situation during labour. The visual indicator may be displayed as part of the graphical user interface module or in a separate display at a remote location. Any suitable type of visual indicator may be used. Examples of visual indicators that may be used include, without being limited to:
In a second specific implementation, the alarm event includes causing an audio signal to be issued, alone or in combination with a visual indicator, to draw attention of a user of the graphical user interface module. In this second specific implementation, the processing unit 206 (shown in
In a third specific implementation, the alarm event includes causing a message signal to be transmitted to a remote device. The remote device may be, for example, a PDA, telephone, pager or a remote computing terminal. Other suitable types of remote devices may also be envisaged in other specific implementations of the present invention. In this third specific implementation, the processing unit 206 (shown in
In a first practical example of interaction, the remote device is a PDA assigned to a doctor responsible for overseeing deliveries in a hospital. At least in part based on the value of the contractility persistence index, the graphical user interface module selectively sends a message through the data interface 210 and over a network to the PDA of the doctor to alert that doctor. The message may include any suitable useful information including, but not limited to, the name of the obstetrics patient, the location of the patient, the contraction rate, the value of the contractility persistence index, contraction medication information, fetal heart rate information, labour progression information (duration of labour, time since admission to hospital) and medical history. Optionally, the message may also enable the PDA of the doctor to display all or part of the user interface module described in the present application. For example, the message may enable the PDA of the doctor to display a user interface of the type depicted in
In second practical example of interaction, the remote device is a remote computing terminal located at a centralised nursing station in a hospital birthing centre. At least in part on the value of the contractility persistence index, the graphical user interface module selectively causes a message to be sent to the remote computing terminal. Advantageously, by allowing a message to be transmitted to a remote device, the clinical staff need not be located near the patient or in proximity to the patient to be alerted to potentially problematic situations. In addition, the clinical staff need not be expressly monitoring the progression of the contraction rate to be alerted to an unsafe condition.
An exemplary embodiment of the process implemented by the graphical user interface will now be described with reference to
For the purpose of this example, the contractility persistence index includes four levels defined as follows:
With reference to
At step 302, the graphical user interface module computes a contraction rate on the basis of the contraction signal received at step 300.
The specific manner in which the contraction rate is computed will depend on the format of the contraction signal. In a first specific example, the contraction signal is a continuous signal conveying the intensity of the uterine contractions over time. A non-limiting graphical representation of such a continuous signal is depicted in
In a second specific example, the contraction signal received at input 202 is comprised of unitary signal events where a signal event is generated when a contraction event is detected. A non-limiting graphical representation of such a continuous signal is depicted in
In a specific implementation, the graphical user interface module computes a rate of contraction events in the contraction signal for a certain time segment. The rate of contraction events in the contraction signal may be computed in a number of suitable manners.
In a specific example, a current contraction rate is equal to the number of contraction events detected in the contraction signal over the last time duration T. The duration T may be any suitable time duration. In a non-limiting example, the duration T is 10-15 minutes and the current contraction rate is the number of contraction events in the contraction signal that occurred over the previous 10-15 minutes. Most clinical guidelines describe the desirable contraction frequency based on an observation period of 10-15 minutes. It will be readily apparent to the person skilled in the art that the time duration T may have a duration different than 10-15 minutes. Moreover, the time duration T may be a configurable parameter of the graphical user interface module implemented by processing unit 206 without detracting from the spirit of the invention. Typically, the duration T will be selected to be a time duration sufficiently long so that a few contraction events are likely to occur during active labour but sufficiently short so that the contraction rate for a given time duration T is representative of the progression of the contraction rate during active labour. It will be readily apparent to the person skilled in the art that a very lengthy time duration, let us say 3 hours, does not provide useful information as to whether the contraction rate is within reasonable boundaries. Similarly, a very short time duration, let us say 2 minutes, also does not provide any useful information as to whether the contraction rate is within reasonable boundaries.
It will be readily apparent to the person skilled in the art, in light of the present description, that other well-known techniques for computing a contraction rate on the basis of a contraction signal may be used without detracting from the spirit of the invention.
In a specific example of implementation, the contraction rate is computed every 2 minutes for the previous 10 minutes time segment. In other words, the contraction rate is expressed as the number of contraction for a 10-minute time interval and is computed every 2 minutes for the preceding 10-minute time interval.
At step 350 the system performs a comparison to determine whether the computed contraction rate exceeds the limit set by a threshold contraction rate. The threshold contraction rate is a configurable parameter in the system and will typically be set by hospital policies or best medical practice rules. If step 350 is answered in the negative and the computed contraction rate does not exceed the limit set by threshold contraction rate, the system proceeds to step 351 where the contractility persistence index for that time interval is set to Level 1. The system then displays that information graphically and proceeds to optional step 308. If optional step 308 is omitted from the implementation, the system returns to step 300 to process the next time interval.
If step 350 is answered in the affirmative and the computed contraction rate exceeds the limit set by threshold contraction rate, the system proceeds to step 352 where an additional condition is tested.
At step 352 the graphical user interface module determines whether the computed contraction rate has exceeded the limit set by the threshold contraction rate for a time duration exceeding a second predetermined time duration. This step 352 allows testing whether the excess of the contraction rate is merely transient of whether it is sustained. The predetermined time duration may be established on the basis of a hospital policy or, alternatively, on the basis of other clinical guidelines. In a non-limiting implementation, the time duration used in at step 352 is 20 minutes.
If step 352 is answered in the affirmative and the computed contraction rate exceeds the limit set by threshold contraction rate for a duration of time exceeding the predetermined time duration of 20 minutes, the system proceeds to step 353 where the contractility persistence index for that time interval is set to Level 4. The system then displays that information graphically and proceeds to optional step 308. If optional step 308 is omitted from the implementation, the system returns to step 300 to process the next time interval.
If step 352 is answered in the negative and the computed contraction rate has not exceeded the limit set by threshold contraction rate for a duration of time exceeding 20 minutes, the system proceeds to step 357 where an additional condition is tested.
At step 357 the graphical user interface module determines whether the computed contraction rate has exceeded the limit set by the threshold contraction rate for a time duration exceeding a first predetermined time duration. In a non-limiting implementation, the first predetermined time duration used at step 357 is 10 minutes.
If step 357 is answered in the affirmative and the computed contraction rate exceeds the limit set by the threshold contraction rate for a duration of time exceeding the predetermined time duration of 10 minutes, the system proceeds to step 361 where the contractility persistence index for that time interval is set to Level 3. The system then displays that information graphically and proceeds to optional step 308. If optional step 308 is omitted from the implementation, the system returns to step 300 to process the next time interval.
If step 357 is answered in the negative and the computed contraction rate has not exceeded the limit set by threshold contraction rate for a duration of time exceeding 10 minutes, the system proceeds to step 359 where the contractility persistence index for that time interval is set to Level 2. The system then displays that information graphically and proceeds to optional step 308. If optional step 308 is omitted from the implementation, the system returns to step 300 to process the next time interval.
Specific non-limiting examples of formats for the display of the information were described with reference to
Step 308 is an optional step and may be omitted from certain specific implementations. At step 308, the graphical user interface module determines, at least in part on the basis of the computed contractility persistence index, whether an alarm event should be caused.
As will become apparent to the person skilled in the art in light of the present specification, different conditions may bring the graphical user interface module to cause an alarm event.
In a first specific example of implementation, an alarm event is triggered depending on the specific circumstances conveyed by the contractility persistence index alone.
In a second specific example of implementation, an alarm event is triggered depending on the specific circumstances conveyed by the contractility persistence index in combination with other factors. Such other factors may include, without being limited to, contraction medication information and fetal heart rate information.
In either one of the above described specific examples of implementation, the conditions for causing an alarm event may be determined on the basis of a hospital policy or in accordance with best recognised practices in health care.
In a specific example of implementation, step 308 shown in
As depicted, at step 325 the graphical user interface module determines whether the contractility persistence index exceeds the limit set by a first threshold contractility persistence index. If step 325 is answered in the negative and the computed contractility persistence index does not exceed the limit set by the first threshold contractility persistence index, step 308 determines that no alarm should be caused and the graphical user interface proceeds to step 300.
If step 325 is answered in the affirmative and the computed contractility persistence index exceeds the limit set by the first threshold contractility persistence index, the graphical user interface proceeds to step 326 where an additional condition is tested. In a specific example, the first threshold contractility persistence index is set to Level 3. As such, a contractility persistence index having a value of Level 3 or higher will be further considered to determine whether an alarm should be caused.
At step 326 the graphical user interface module determines whether the computed contractility persistence index has exceeded the limit set by a second threshold contractility persistence index. This step 326 allows testing the severity of the persistence of an elevated contraction rate. In a specific example, the second threshold contractility persistence index is set to Level 4.
If step 326 is answered in the affirmative and the computed contractility persistence index exceeds the limit set by the second threshold contractility persistence index indicating that the excess of the contraction rate is sustained and severe, step 308 determines that an alarm event should be caused and the graphical user interface proceeds to step 310 where an alarm event is caused to occur. As such, in the present specific example of implementation, a contractility persistence index having a value of Level 4 will be considered severe enough to cause an alarm on its own without considering other factors.
If step 326 is answered in the negative and the computed contractility persistence index has not exceeded the limit set by the second threshold contractility persistence index, the graphical user interface module proceed to step 327 where an additional condition is tested.
At step 327 the graphical user interface module determines whether the contraction medication information indicates that contraction inducing medication was given to the obstetrics patient. Optionally, step 327 may also evaluate the level (or dosage) of contraction inducing medication and use that information in effecting the decision step 327.
If step 327 is answered in the affirmative and the contraction medication information indicates that contraction inducing medication was given to the obstetrics patient, step 308 determines that an alarm event should be caused and the graphical user interface proceeds to step 310.
If step 327 is answered in the negative and the contraction medication information indicates that contraction inducing medication was not given to the obstetrics patient, the graphical user interface module proceed to step 329 where an additional condition is tested.
At step 329 the graphical user interface module determines whether the fetal heart rate information available indicates a problematic risk level associated with the baby's well-being. The fetal heart rate information may include a fetal heart rate signal or, alternatively, may include information conveying a level of risk associated with the fetus, the level of risk being derived on the basis of a fetal heart rate signal. In a specific example of implementation, the fetal heart rate information includes a fetal heart rate signal and is received from the fetal heart rate sensor 110 (shown in
If step 329 is answered in the affirmative and the fetal heart rate information indicates a problematic risk level associated with the baby's well-being, step 308 determines that an alarm event should be caused and the graphical user interface proceeds to step 310.
If step 329 is answered in the negative and the fetal heart rate information does no indicates a problematic risk level associated with the baby's well-being, step 308 determines that no alarm should be caused and the graphical user interface proceeds to step 300.
Although step 327 is shown in
In the specific example of implementation shown in
Returning now to
If step 308 determines that no alarm event should be caused, the graphical user interface module returns to step 300 where the next segment of the contraction signal is received and subsequently processed.
As can be observed, the process illustrated in
Although the exemplary embodiment of the process implemented by the graphical user interface described with reference to
As a variant, the graphical user interface module is adapted for displaying, concurrently with the contractility persistence index additional information elements related to maternal and fetal well-being and/or labour progression.
As shown, the graphical user interface module displays a first viewing window 570 conveying the value of the contractility persistence index over time. In this example a colour scheme is used to convey different values of the index over time. In this specific example, a first tracing 574 conveying rates of uterine contractions over time and a second tracing 572 conveying a threshold rate of uterine contractions are superposed onto the contractility persistence index in first viewing window 570. The graphical user interface module also displays a second viewing window 558 including a tracing 582 conveying a uterine contraction pattern over time (TOCO tracing) and a tracing 584 conveying a fetal heart rate pattern over time. The tracing 582 conveying a uterine contraction pattern over time is derived on the basis of the contraction signal received from the uterine activity sensor 120 (shown in
Advantageously, the display of the tracing 584 conveying a fetal heart rate pattern over time allows the users of the system to view a representation of the baby's response to the contraction events.
The display of the tracing 582 conveying a uterine contraction pattern over time allows the users of the system to view a representation of the original contraction signal and to assess whether the tracing 574 conveying rates of uterine contractions over time accurately reflects the rate of contractions in the original contraction signal. This is particularly useful when the contraction signal generated by the uterine activity sensor part of the electronic fetal monitor 110 (shown in
In the embodiment depicted, the graphical user interface module also displays a control 556 allowing a user to select a portion of the tracings in the first viewing window 570 and/or the second viewing window 558. The user is enabled to manipulate the control 556 by providing signals using user input device 118 (shown in
In a specific implementation, the control 556 includes a selection box having a transparent portion superposed upon the first viewing window 570 and the second viewing window 558. The portions of the tracings viewable through the transparent portion correspond to the selected portions. The control 556 allows the user to displace and modify the size of the selection box to select a portion of the tracings. Other manners in which portions of a signal may be selected are described in U.S. Pat. No. 6,907,284 issued to E. Hamilton et al. on Jun. 14, 2005. The contents of this document are incorporated herein by reference.
In the embodiment depicted, the control 556 is a sliding window superposed on the viewing windows 570558 and 560. This sliding window is moveable along the time axis (x-axis) such as to allow the user to select a desired time segment. Optionally, and as shown in the embodiment depicted, the graphical user interface module also displays information related to the portion of the tracings selected by the control 556. Such information may include characteristics such as:
It will be appreciated that the above examples of information is not intended to be an exhaustive list and that other types of information may be provided without detracting from the spirit of the invention.
In the embodiment depicted in
Advantageously, by displaying zoomed-in views of the selected portions of the tracings 582 and 584, a user will be able to better view responses of the fetal heart rate to individual contraction events (amount of variability size and type of deceleration) and will be able to better assess the intensity and duration of a given contraction event.
In the embodiment depicted, the graphical user interface module also displays a fourth viewing window 560 including a tracing 561 conveying information associated to administration of contraction inducing medication to the obstetrics patient. The tracing 561 is derived on the basis of contraction medication information received by apparatus 100 (shown in
Advantageously, the tracing 561 allows the clinical staff to readily view whether contraction inducing medication was administered to the obstetrics patient being monitored (and optionally the amount of contraction inducing medication that was administered).
As shown, the graphical user interface module displays a viewing window 870 including a tracing 850 conveying a uterine contraction pattern over time (TOCO tracing) and a tracing 852 conveying a fetal heart rate pattern over time. The tracing 850 conveying a uterine contraction pattern over time is derived on the basis of the contraction signal received from the uterine activity sensor 120 (shown in
The viewing window 870 also includes a control in the form of a selection box 856 having a transparent portion superposed on the tracings 850852 and 854. The portions of the tracings or time signals viewable through the transparent portion correspond to selected portions of the tracings. The selection box 856 is moveable along the time axis (x-axis) such as to allow the user to select a desired time segment. The size of the selection box 856 can also be modified such as to include a larger portion of the tracings. Below the selection box 856 appears information related to characteristics of the tracings within the transparent portion. More specifically, in the example depicted, an indication of the average number of contraction within the viewing window is presented. When the window is displaced along the x-axis, the information appearing below is accordingly updated to reflect the characteristics of the new portion of the tracings selection by selection box 856.
The viewing window 870 also includes a tracing 858 conveying a fetal heart rate pattern over time and a tracing 860 conveying a uterine contraction pattern over time (TOCO tracing). The tracing 858 conveying a fetal heart rate pattern over time corresponds to the selected portion of the tracing 852 and is a zoomed-in view of the selected portion of tracing 852 selected by selection box 856. The tracing 860 conveying a uterine contraction pattern over time (TOCO tracing) corresponds to the selected portion of the tracing 850 in the second viewing window 558 and is a zoomed-in view of that selected portion.
Those skilled in the art should appreciate that in some embodiments of the invention, all or part of the functionality previously described herein with respect to the apparatus 100 (shown in
In other embodiments of the invention, all or part of the functionality previously described herein with respect to the apparatus 100 (shown in
The apparatus 100 (shown in
It will be appreciated that the system 150 depicted in
The server system 910 includes a program element 960 for execution by a CPU. Program element 960 implements similar functionality as program instructions 706 (shown in
Those skilled in the art should further appreciate that the program instructions 706 and 960 may be written in a number of programming languages for use with many computer architectures or operating systems. For example, some embodiments may be implemented in a procedural programming language (e.g., “C”) or an object oriented programming language (e.g., “C++” or “JAVA”).
Although the present invention has been described in considerable detail with reference to certain preferred embodiments thereof, variations and refinements are possible without departing from the spirit of the invention. Therefore, the scope of the invention should be limited only by the appended claims and their equivalents.
This application is related to: U.S. patent application entitled “METHOD AND APPARATUS FOR PROVIDING CONTRACTION INFORMATION DURING LABOUR” filed on Mar. 9, 2007 by Emily Hamilton and which was assigned Ser. No. 11/716,496; andU.S. application entitled “METHOD AND APPARATUS FOR DISPLAYING LABOUR RELATED INFORMATION ASSOCIATED TO AN OBSTETRICS PATIENT” filed on May 1, 2006 by Emily Hamilton and which was assigned Ser. No. 11/416,281. In addition, for the purpose of the United States, this application claims the benefit of priority under 35 USC §120 based on U.S. provisional patent application Ser. No. 61/012,619 filed Dec. 10, 2007 by Emily Hamilton et al. The contents of the above identified documents are incorporated herein by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/CA08/02134 | 12/5/2008 | WO | 00 | 6/9/2010 |
Number | Date | Country | |
---|---|---|---|
61012619 | Dec 2007 | US |