EP0394270A1 - Timing device - Google Patents

Abstract

Synchronization device for cardiopulmonary resuscitation (CPR), in the form of a wristwatch (10) provided with a set of auxiliary push-buttons (13, 14 and 15). When a push button (13, 14 or 15) is pressed, a beeper (16) produces sound signals at a rate which is a function of the pressed button (13, 14 or 15) used to rhythm an external cardiac massage. The appropriate light of a set of lights (23, 24 or 25) of push buttons associated with the respective push buttons (13, 14 or 15), lights up in synchronization with the sound signals in order to synchronize the CPR in noise ranges. The synchronization device also records the time elapsed since the start of the CPR signals as well as the number of synchronization signals produced.

Description

"TIMING DEVICE"

-- BACKGROUND OF THE INVENTION --

This invention relates to an improved timing device and in particular it relates to a timing device which may be used in emergency situations to provide compression rates for manual cardio-pulmonary resuscitation techniques.

Cardio-pulmonary resuscitation techniques for reviving patients are well known and their use is wide-spread. Such techniques are extremely effective when correctiy carried out and have resulted in the saving of many lives. While many people have a basic understanding of the technique, most people are untrained and are incapable of effectively administerins cardio-pulmonary resuscitation techniques in an emergency. One of the critical factors in the technique is the timing of the chest compressions. This varies with the age of the patient. Skilled resusci tators are practiced in performing the chest compression function at a relatively constant predetermined rate. Various techniques have evolved to enable the correct rate to be achieved, but practice is still needed to maintain reliable performance of the resuscitation technique.

In an emergency, the time taken to commence resuscitation is critical to the survival chances of the patient and it is desirable that there be no delay in commencing the technique. Thus a person skilled in the art of cardio-pulmonary resuscitation has a far greater chance of reviving a patient than does a person who is aware of the technique and its application, but who may have lost the necessary skill to accurately perform the required chest compressions.

Unfortunately, while the basic technique is relatively easy to remember, it is difficult for most people to remember techniques to perform the compressions at the required rate. Furthermore, the duration of cardio-pulmonary resuscitation prior to clinica l care may influence doctors decisions as t o the further treatment required for a patient, and this information is rarely recorded in any way during emergency treatment by other than highly experienced personnel.

This invention aims to alleviate the abovementioned problems and to provide timing apparatus which will be reliable and efficient in use. Other objects and advantages of this invention will hereinafter become apparent.

-- SUMMARY OF THE PRESENT INVENTION --

With the foregoing and other objects in view, this invention in one aspect resides broadly in a timing device having indicator means for indicating chest compression rate time interval signals for cardio-pulmonary resuscitation techniques and switching means for selecting a desired compression rate.

Preferably, the indicator means includes an audible alarm which will repeatedly sound at the desired chest compression rate and/or visual indication means which will provide a corresponding display of the selected compression rate. Alternatively, or in addition, visual indication means may be provided, and may take the form of a visual display corresponding to the desired compression rate. The audible alarm may also be adapted to produce for producing lung inflation synchronization signals at a selected lung inflation rate. The lung inflation rate may be any desired rate, but it is preferred that it be programmed to a selected fraction of the chest compression rate whereby the lung inflation rate may be varied proportionally to the chest compression rate by operation of the switching means. The switching means may include a plurality of switch assemblies, for instance three switch assemblies, and each of the switch assemblies may be associated with a respective recognition means appropriate to a selected compression rate. The recognition means may be the numerals 60, 80 and 100 applied to respective ones of the switching means corresponding to the compression rates appropriate for patients within various age groups and for the number of operators performing cardio-pulmonary resuscitation. Alternatively, the recognition means may include symbols relating to the physical condition of patients and/or the number of available operators, the symbols being applied to respective ones of the switch assemblies. If desired, the recognition means may include colours, such as yellow, blue and red applied to respective switch assemblies.

In a preferred form, each recognition means may be formed as a visual indication means associated with a respective switch, and the respective visual indication means associated with a selected switch may be designated by an annunciating action such as illumination. Suitably, this may be a light which flashes at the selected time interval in synchronism with the audible signal.

Elapsed time interval indication means may be provided, and may be associated with internal timing means in the form of a stop watch which commences timing upon activation of the indication means and operates a numerical visual display relating to the elapsed time or the number of time interval signals generated subsequent to the current activation of the indicating means. Preferably the arrangement is such that the numerical visual display is provided which indicates the duration of the cardio-pulmonary resuscitation as well as the rate and/or number of chest compressions used during that period. If necessary, a plurality of displays may be provided to display the duration of periods at varying rates of compression such as for example, at start up and during subsequent treatment. This arrangement has the advantage that, when clinical care becomes available, the clinicians may review the time history of the cardio-pulmonary resuscitation to determine the duration and timing of the C.P.R. operations carried out to that point in time. Alternatively, a single numerical display may be provided, and may be utilised for the successive display of a plurality of rates.

The timing device may be provided as a separate unit which provides no other function. However, it is preferred that the timing device be incorporated into a conventional watch, such as a wrist, pocket or fob watch or the like, so that it is readily available for use. Preferably the watch has an analogue/digital display having a second hand which sweeps a watch face divided into quarters whereby the watch may be conveniently usable for checking pulse rates. Of course the timing device can be in the form of a clock or the like which may be advantageously used as a fixed installation in hospital wards, ambulances and the like. In such installations, the digital display may be on L.C.D. type display so as to provide easy recognition in fully lit areas In a further embodiment a mode button is provided which actuates a cyclic display of functions which may be selected by stopping the display at the appropriate function. This may include functions for adult, child or infant as well as a function for changing the inflation timing and or compression rate for operations by a single operator (two inflations every fifteen compressions), or for operation by two operators (one inflation every five compressions), and a function for inflation cycle only for use on patients with a pulse or for practicing cardio-pulmonary resuscitation.

In a further aspect, this invention resides in a timing device as defined above, wherein there are included the following functional capabilities:- (i) sounding of an audible timing signal at a timing rate of approximately sixty cycles per minute;

(ii) sounding of an audible timing signal at a timing rate of approximately eighty cycles per minute;

(iii) sounding of an audible timing signal at a timing rate of approximately one hundred cycles per minute;

(iv) accompanying said audible timing signal with a visual timing signal;

(v) counting and displaying the number of cycles or the elapsed timing period at a selected timing rate or a plurality of selected timing rates;

(vi) displaying the time of day.

-- BRIEF DESCRIPTION OF THE DRAWINGS --

In order that this invention may be more readily understood and put into practical affect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of a wrist watch made according to the present invention, wherein:-

FIG. 1 illustrates an analog-display wrist watch according to the invention; FIG. 2 illustrates the digital display of the wrist watch illustrated in FIG. 1, and

FIG. 3 is a block diagram of the wrist watch shown in

FIGS. 1 and 2. -- DESCRIPTION OF THE PREFERRED EMBODIMENT --

As shown in FIG. 1, the analog-display wrist watch 10 is a modified watch having a conventional watch face 11 provided with second, minute and hour hands and a digital time display 12. In addition, the watch face 11 supports three colour- coded buttons 12, 14 and 15 which in this instance are marked with the numerals 60, 80 and 100. These numbers represent the three rates of chest compression commonly required for performing cardio-pulmonary resuscitation. The buttons 13, 14 and 15 incorporate liquid crystal button displays 23, 24 and 25 respectively, and are colour coded. The button 13 is yellow, the button 14 is blue and the button 15 is red. An audible alarm or beeper 16 is built into the watch 10 and this is adapted to provide a repeating audible signal at the frequency indicated on the control buttons, namely 60 signals per minute, 80 signals per minute and 100 signals per minute respectively. It will also be seen that the watch face 11 includes quarter-minute segments to facilitate measuring of fifteen-second pulse rates. In an emergency, a person wearing the watch 10 can apply cardio-pulmonary resuscitation techniques in an accurate manner by firstly pressing the appropriate button 13, 14 or 15 in accordance with the age group of the patient, or the number of operators performing C.P.R., and then regulating their rate of manual chest compressions to correspond to that indicated by the audible signal provided by the watch 10 or by the flashing of the selected button display 23, 24 or 25 which flashes in synchronism with the audible signal whereby the operator or operators may readily check that the appropriate rate is being used.

Thus in circumstances where external noise may drown out the noise from the beeper 16, the operator can maintain the selected rate by observing the watch face 11. In other circumstances in which the beeper 16 can oe clearly heard, the person may direct their attention elsewhere while at the same time maintaining an accurate rate of chest depression in time with the audible signal.

In use, the mode button 17 is pressed to activate the C.P.R. functions and the appropriate button 12, 14 or 15 is pressed. The digital time display 12 is automatically replaced by the display shown in FIG. 2. This includes a pulse rate display 18, a pulse counter 19 and an inflation indicator 20. The latter is displayed at the appropriate pulse count sequence, depending upon the button 12, 14 or 15 pressed, to indicate the appropriate timing for lung inflations such as by mouth-to-mouth resuscitation. At the same time, the stop watch display 21 provides the duration of resuscitation. This display remains as a reference until the reset button 22 is pressed. A further alarm or pause in the sequence may be provided to indicate to the operator to stop compressions and check for a patient's pulse.

It will of course be realised that the above has been given only by way of illustrative example of the invention and that all such modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as is defined herein in the appended claims.

Claims

-- CLAIMS --

1. A timing device having indicator means f o r indicating chest compression rate time interval signals for cardio- pulmonary resuscitation techniques and switching means for selecting a desired compression rate.

2. A timing device as defined in Claim 1, wherein said indicator means includes an audible alarm for producing chest compression synchronization signals at said desired compression rate.

3. A timing device as defined in Claim 1 or Claim 2. wherein there is provided visual indication means for providing a visual display corresponding to said desired compression rate.

4. A timing device as defined in any one of the preceding claims, wherein said switching means includes include three switch assemblies, each of said switch assemblies being provided with recognition means for said selected compression rate.

5. A timing device as defined in Claim 4, wherein said recognition means includes the numerals 60, 80 and 100 applied to respective ones of said switch assemblies.

6. A timing device as defined in Claim 4 or Claim 5, wherein said recognition means includes symbols relating to the physical condition of patients applied to respective ones of said switch assemblies.

7. A timing device as defined in any one of Claims 4 to 6, wherein the recognition means associated with a selected switch assembly includes visual indication means.

8. A timing device as defined in Claim 7 wherein said recognition means is energised in synchronism with the energization of said audible alarm.

9. A timing device as defined in any one of Claims 2 to

8, wherein said indicator means is adapted for producing lung inflation synchronization signals at a selected lung inflation rate.

10. A timing device as defined in any one of the preceding claims, wherein there is provided visual elapsed time interval indication means initiated by activation of said indication means.

11. A timing device as defined in any one of the preceding claims, wherein there is provided a numerical visual display relating to the number of said time interval signals generated subsequent to the current activation of the indicating means.

12. A timing device as defined in Claim 10, wherein said numerical visual display is one of a plurality of numerical displays, each said numerical visual display relating to the number of said time interval signals generated subsequent to the current activation of said indication means at respective selected compression rates.

13. A timing device as defined in any one of the preceding claims, wherein said timing device is associated with time-keeping means, said timing device and said time- keeping means being enclosed within a common housing.

14. A timing device as defined in any one of the preceding claims, wherein said time-keeping means has an analogue /digital display having a second hand which sweeps a watch face divided into quarters whereby the watch may be used for checking pulse rates.

15. A timing device as defined in any one of the preceding claims, wherein said time-keeping means and said timing device utilise integrated circuit technology.

16. A timing device as defined in any one of the preceding claims, wherein there are included the following functional capabilities:-

(i) sounding of an audible timing signal at a timing rate of approximately sixty cycles per minute;

(ii) sounding of an audible timing signal at a timing rate of approximately eighty cycles per minute;

(iii) sounding of an audible timing signal at a timing rate of approximately one hundred cycles per minute;

(iv) accompanying said audible timing signal with a visual timing signal;

(v) counting and displaying the number of cycles or the elapsed timing period at a selected timing rate or a plurality of selected timing rates;

(vi) displaying the time of day.

17. A timing device substantially as hereinbefore described with reference to the accompanying drawings.