THE USE OF AN AED

The present invention relates to a system for training or testing skills in cardiac pulmonary resuscitation (CPR) and the use of an automated external defibrillator (AED). Victims of cardiac arrest generally exhibit ventricular fibrillation at some point during the arrest. Resuscitation is most successful if defibrillation is performed within 5 minutes of collapse. Since the response time of the emergency medical services will often be longer than 5 minutes, achieving a high survival rate depends on establishing widespread competence in life support skills amongst the general public. Medical training systems for teaching life support skills are known and one such system is disclosed in WO2009/018334. The known medical training systems tend to be expensive and/or lack portability. Both of these factors are detrimental to the goal of establishing widespread competence in life support skills amongst the general public.

According to a first aspect, the present invention may provide a system for training or testing skills in cardiac pulmonary resuscitation (CPR) and the use of an automated external defibrillator (AED), comprising: a manikin comprising a body and a plurality of capacitive sensors located at predetermined locations in or on the body; an AED simulator comprising dummy first and second defibrillator pads; wherein a first group of the capacitive sensors is operable to detect the close presence of a said defibrillator pad and a second group of the capacitive sensors is operable to detect the close presence of a human hand.

A system according to the first aspect of the present invention by using capacitive sensors, that are simple and inexpensive, to detect more than one type (apparently) of external stimulus assists in keeping the cost of the system low. Notably, the defibrillator pads need not have any current delivering or voltage applying capability at all.

Preferably, the system further comprises a third group of capacitive sensors that are operable to detect the close presence of a member forming part of the manikin. In this way, the capacitive sensors are used in a third distinct role which further contributes to keeping the costs of the system low.

A said capacitive sensor of the third group may form part of a head tilt detection switch. In one embodiment, the body comprises a torso and a head tiltable by means of a head tilt mechanism with respect to the torso, and the said capacitive sensor of the third group is operable to detect the close presence of a member of the head tilt mechanism. A said capacitive sensor of the third group may form part of a slide switch of the AED simulator. In one embodiment, the AED simulator comprises a slide switch comprising a member slidable between first and second positions, and the said capacitive sensor of the third group is operable to detect the close presence of said member. Preferably, the system is operable, for at least a said sensor of the first or second group, to distinguish between the close presence of a human hand and that of a said defibrillator pad. By virtue of this feature, a sensor can be dynamically shifted from the first group in which it is operable to detect the close presence of a said defibrillator pad to the second group in which it is operable to detect the close presence of a human hand or vice versa according to the role required of it, at a given moment, during a training or testing session.

Preferably, the system comprises a capacitance measuring circuit operable to repeatedly measure the capacitance presented to the capacitance measuring circuit by each of said capacitive sensors. In one embodiment, the system is arranged such that the capacitance measuring circuit is selectively connectable to each of said capacitive sensors individually. In another embodiment, the system is arranged such that the capacitance measuring circuit is selectively, connectable to successive groupings of said capacitive sensors, wherein within a said grouping the capacitive sensors are physically remote from one another, thereby avoiding mutual interference during measurement.

Preferably, the capacitance measuring circuit is operable to measure the capacitance of a said capacitive sensor by measuring the time taken to charge it to a predetermined voltage.

Preferably, the system is operable, for each of said capacitive sensors, to apply a clustering algorithm to the measured capacitance samples or data derived therefrom. The clustering algorithm may be used to distinguish between when there is no foreign body (i.e. no hand, defibrillator pad or member forming part of the manikin) near the capacitive sensor and a presence event when a foreign body is near the capacitive sensor. The clustering algorithm may also be used to distinguish between an as-intended presence event and an unintended presence event. The system may comprise other sensors that are not capacitive sensors, such as a simple switch.

Preferably, all the sensors are mounted on a flexible membrane, for example, a printed circuit board, that overlays the body. In this way, through the appropriate design of layout of the printed circuit board, the positioning of the sensors about the body can be readily achieved. The sensors may also been mounted on a plurality of rigid printed circuit boards interconnected by flexible parts.

In a preferred embodiment, a said other sensor comprises an accelerometer mounted on the flexible membrane for measuring the compression of the chest region. Such an embodiment is advantageous since it enables all the sensors necessary for hand and defibrillator pad presence detection and chest region compression to be mounted on the flexible membrane.

A said group may comprise a single capacitive sensor.

A said sensor of the first group may also be capable of detecting the presence of a human hand and a said sensor of the second group may also be capable of detecting the presence of a dummy defibrillator pad.

In the context of the present invention, close presence refers to a range preferably within 1mm, more preferably within 2mm, and still more preferably within 4mm of the surface of the sensors.

In accordance with (all aspects of) the present invention, the representation of the human body that the manikin provides need not be particularly realistic, for example, it might look like a human-like robot or provide some other analogous representation. According to a second aspect, the present invention may provide a sensor membrane for a manikin providing a representation of a human torso, and optionally head, used in training or testing skills in cardiac pulmonary resuscitation (CPR) and the use of an automated external defibrillator, comprising: a membrane that is flexible to allow it to move from a planar condition to a non-planar condition in which it may lie in conformity with contours of the manikin; and a plurality of capacitive sensors mounted on the membrane in a pattern that, when fitted to the manikin, positions the capacitive sensors at locations on the manikin corresponding to locations on the human anatomy to which a defibrillator pad or a human hand should be applied during training or testing.

It will be appreciated that the relative disposition of the capacitive sensors according to the second aspect of the present invention is unique to this application being dictated as it is by human anatomy.

The sensor membrane of the second aspect of the present invention permits the benefits of the first aspect of the present invention to be realised with existing manikins. Existing manikins vary in the extent that they mechanically mimic features of the human body and hence in their cost. But for a given class/size of manikin, for example, one that represents an adult-sized body, there is naturally great dimensional similarity. As a result, a single embodiment of the second aspect of the present invention may be used with a range of existing manikins of the same class/size. Preferably, a first group of the capacitive sensors are arranged to detect a defibrillator pad and a second group of the capacitive sensors are arranged to detect a human hand.

The flexibility of the membrane allows the sensor membrane to

be manufactured in its planar condition and then fitted to a manikin for use. The membrane being able to assume a planar condition makes the mounting of the capacitive sensors a routine and simple manufacturing operation. However, it will be appreciated (for example, with reference to Figure 7) that the sensor membrane needs careful design to ensure that the sensors as mounted when the membrane is in its planar (i.e. 2D) condition can become correctly positioned when the sensor array is fitted to the manikin.

Preferably, the sensor membrane further comprises a third group of the capacitive sensors which are correctly positioned so as to detect a member forming part of the manikin when the membrane is fitted to the manikin. Preferably, the membrane comprises a plurality of arms on which ones of said sensors are mounted.

Preferably, the sensor membrane comprises a plurality of conductors

each connected to a respective said sensor. The conductors may converge at a connector by which the sensor membrane is electrically connected to an external controller.

The sensor membrane may have other sensors or a controller mounted thereon. In a preferred embodiment, a said other sensor comprises an accelerometer that is positioned on the membrane such that when the sensor membrane is fitted to the manikin it is positioned on the chest region of the torso. Such an embodiment is advantageous since it enables all the sensors necessary for hand and defibrillator pad presence detection and chest region compression detection to be mounted on the membrane. Preferably, the sensor membrane comprises a first said sensor positioned on the membrane such that when the sensor membrane is fitted to the manikin it is positioned on the lower left-side of the torso to detect a defibrillator pad and a second said sensor positioned on the membrane such that when the sensor membrane is fitted to the manikin, it is positioned on the upper right-side of the torso to detect a defibrillator pad. Preferably, the sensor membrane further comprises a third said sensor positioned on the membrane such that when the sensor membrane is fitted to the manikin it is positioned on the left shoulder of the torso to detect a human hand. Preferably, the sensor membrane further comprises a fourth said sensor positioned on the membrane such that when the sensor membrane is fitted to the manikin it is positioned on the right shoulder of the torso adjacent the second sensor to detect both a defibrillator pad and a human hand.

In a preferred embodiment, the membrane may comprise a flexible printed circuit board. In other embodiments, the membrane comprises rigid printed circuit boards interconnected by flexible parts.

According to a third aspect, the present invention may provide a combination comprising a manikin body having a sensor membrane according to the second aspect of the present invention supported on the manikin body. The

combination may further comprise an outer skin membrane enveloping the manikin body and the sensor membrane.

According to a fourth aspect, the present invention may provide a system for training or testing skills in cardiac pulmonary resuscitation (CPR) and the use of an automated external defibrillator (AED), comprising: a manikin; a case for the manikin comprising a base and a lid; wherein the manikin is fixedly mounted to the base such that when the case is opened the manikin is in a predetermined orientation relative to the base.

A system according to the fourth aspect of the present invention by fixedly mounting the manikin to the base guarantees that when the case is in an open condition, then the manikin is automatically presented in an orientation ready for training or testing.

Preferably, the lid is hingedly mounted to the base. In this embodiment, the lid may advantageously be used as a support platform for the user. The lid may comprise regions suitable for receiving or adapted to receive the user's knees. The regions may be visually distinct from the surrounding portions of the lid. The lid may carry dummy CPR and AED control paraphernalia. Preferably, the manikin is inflatable and comprises a body comprising a head and a torso, and, in the inflated condition, the head may project outside of the base when the case is in an open condition. The manikin may comprise a valve by which it may be inflated. In one embodiment, the body comprises a first inflator located within the torso, and a second inflator located within the head or torso.

Preferably, the body further comprises a head assembly constructed to bias the head into an at-rest position on the torso and to permit the head to be moved, against said bias, into a chin-lift position. Preferably, the body further comprises a lung-bag embedded within the torso and connected to a mouth opening of the head via the head assembly, wherein, in said at-rest position, the head assembly closes off a main volume of the lung-bag from the mouth opening, and, in said chin-lift position, the main volume of the lung bag is open to the mouth opening.

Preferably, the torso is resiliently compressible. In one embodiment, the torso comprises a rigid chest plate. A system having the arrangement of sensors according to the first aspect of the invention may be used in combination with a system having the mechanical construction according to the fourth aspect of the invention.

According to a fifth aspect, the present invention may provide a skillstation.

In the context of the present invention, "or" is used in a non mutually exclusive sense.

Exemplary embodiments of the present invention are hereinafter described with reference to the accompanying drawings, in which:

Figure 1 shows an embodiment of the present invention ready for use;

Figure 2 shows an air-bag defining the basic body shape of the manikin;

Figures 3(a), (b) show different perspective views of a chest plate;

Figures 4(a), (b) show different perspectives of a skin membrane; Figure 5 shows a central longitudinal cross-sectional view through the body of the manikin with certain parts not shown; Figures 6(a-c) show central, right-side, and left-side longitudinal cross-sectional views respectively through the head of the manikin; Figure 7 shows a view of the flexible printed circuit board that carries the capacitive sensors resting on a flat surface;

Figure 8 shows the Figure 1 embodiment with the skin membrane of the manikin and certain other parts removed;

Figure 9 shows the overall system layout for a preferred embodiment of the present invention;

Figures 10(a), (b) show the slide switch of the AED controller in two positions; and

Figures ll(a-d) show views of a further embodiment of the present invention.

Figure 12 is a schematical representation of an example of a capacitive sensor of a dummy or circuit board according to the present invention.

A system for training and testing life support skills including skills in cardiac pulmonary resuscitation (CPR) and the use of an automated external defibrillator (AED) is shown in Figure 1 and generally designated 10.

The system 10 comprises a case 12 and an inflatable manikin 20 carried within the case 12. The case 12 comprises a base 13 within which the manikin 20 is fixedly mounted and a lid 14 that is hingedly mounted to the base 13. The manikin 20 comprises a body 22 comprising a torso 24 and a head 26 and lacking arms and legs. Both the torso 24 and the head 26 are inflatable. In the inflated condition shown in Figure 1, the torso 24 is shaped and sized to match the length and width dimensions of the base 13 and protrudes from the case 13 in the depth dimension, and the head 26 projects beyond a side edge of the base 13. In the deflated condition (not shown), the torso 24 descends into the base 13 and the head 26 may be folded about its neck to lie on the torso 24. The lid 14, when in its open position shown in Figure 1, has its outer surface in contact in with the ground and its inner surface 14a facing upwardly thereby to present a pair of knee pads 15a,b to the user. In another embodiment, the knee pads 15a,b form part of a planar member, for example, in the form of a mat, which cover all or most of the surface 14a. The lid 14 further comprises a flap 16 for housing dummy CPR and AED paraphernalia, including a dummy telephone 60 and a dummy AED controller 62 having an AED slide switch 62a. The AED slide switch 62a comprises a cover member 62b slidable between an extended position as shown in Figure 10(a) and a withdrawn position as shown in Figure 10(b). In the Figure 1 position, the flap 16 projects from a side edge of the lid 14 and lies in contact with the ground. The flap 16 is foldable about a hinge portion 16a such that it may lie on the inner surface 14a of the lid 14. From the foregoing, it will be appreciated that, with the case 12 in a closed condition, the system 10 may be conveniently transported to a training and/or testing venue and, once there, can be deployed into its operational condition as shown in Figure 1 by simply opening the case 12, unfolding the head 26 and the flap 16, and inflating the body 22. The integration of the manikin 20, the knee pads 15a,b and the CPR and AED paraphernalia 60,62 into the case 12 guarantees a correct physical starting point of the training and/or testing. Referring to Figure 2, the body 22 comprises an inflatable air-bag 25 having a valve (not shown) by which the air-bag 25 may be inflated and deflated. The air-bag 25 is formed so as to define the general body shape of the manikin 20. The air-bag 25 also defines a cavity 27 formed in the chest region. The opening to the cavity 27 at the chest side is relatively large and the opening to the cavity 27 at the back side is relatively small. Referring to Figures 3(a), (b), the body 22 further comprises a rigid chest plate 28 having a plurality of reinforcement ribs 28a. The chest plate 28 is shaped to sit in the cavity 27 such that it is supported by the air-bag 25 and its upper surface sits flush with the surrounding surfaces of the air-bag 25. Referring to Figures 4(a), (b), the body 22 further comprises a skin membrane 30 which encapsulates the air-bag 25 and the chest plate 28 and provides a human appearance. The skin membrane 30 also obscures the location of sensors which are described later. The skin membrane 30 has sufficient flexibility to allow it to move together with the air- bag 25 as the chest region is depressed by the user by up to a (intended) depth of 6cm from the at-rest torso position shown in Figure 5. In addition, when the air-bag 25 is deflated, the torso 24 descends into the base 13 under the weight of the chest plate 28 and the head 26 may be folded about its neck to lie on the torso 24 as previously described. The body 22 further comprises a lung-bag 31 interposed between the chest plate 28 and the skin 30. In Figure 5, its location in the chest region is indicated by the arrow A although it is not shown in that drawing. The lung-bag 31 extends from the chest region up the torso 24 where it is carried and retained in place by a head assembly 32 as shown in Figure 6(a).

Referring to Figures 6(a-c), the head assembly 32 comprises a neck part 33 having support struts 33a,b (only support strut 33a is visible) disposed on opposite sides of the neck and pivotably mounted to the base 13 such that the head 26 can assume the operational position of Figure 5 and be folded flat onto the torso 24 when deflated as previously mentioned. The head assembly 32 further comprises a chin part 34 and a mouth part 40. The chin part 34 comprises side portions 34a,b that are extensions of the member forming the neck part 33 and a bridge portion 34c connecting between the side portions 34a,b. Each side portion 34a,b comprises an arm 35a,b that is shaped to define a recess for receiving a spring 36a,b. Each side portion 34a,b comprises a first surface 37a,b for carrying a sensor. The mouth part 40 comprises a curved member having at one end a lung-bag connector 41 that is disposed in the vicinity of a mouth opening 26b in the head membrane 26a and at the other end wing portions 42a,b and a tab 43 intermediate the wing portions 42a,b. Each wing portion 42a,b comprises a second surface 38a,b disposed opposite to the respective first surfaces 37a,b for carrying a tab of conductive material 39a,b. The mouth part 40 is mounted to the chin part 34 for rotational movement with respect thereto via left and right hinges 44a,b formed between the side portions 34a,b and the wing portions 42a,b respectively. The springs 36a,b bias the chin part 34 and the mouth part 40 into the relative orientation in which the head 26 is in the regular at-rest head position shown in Figure 5. As is visible in Figure 6(a), the lung-bag 31 is routed into between the bridge portion 34c and the tab 43, where, in the at-rest head position, it is pinched closed between the bridge portion 34c and the tab 43. Referring to Figure 6(b), when the user applies a lifting action to the chin region of the head 26, the mouth part 40 is urged against the bias of the spring 36a,b and rotates clockwise into a chin-lift position. In so rotating, the tab 43 is displaced away from the lung-bag 31 opening up the full volume of the lung-bag 31, whereby the lung-bag 31 may be inflated by the user blowing into the mouth opening 26b. The inflation of the lung-bag 31 may cause the chest region to rise by up to 1cm from the at-rest Figure 5 position. When the user releases the chin, the biases of the springs 36a,b restore the head 26 to its rest position. The head assembly 32 further comprises a nose part 44.

From the foregoing, it will be appreciated that the manikin 20 by providing a moveable chest region, an articulating head and an inflatable lung mimics the relevant mechanical components of the human body necessary to simulate the performance of protocols for CPR and the use of an AED.

In order to detect the interaction of the user with the manikin 20 a set of sensors/transducers Sl-12, SW1-4 is provided. The sensors Sl-12 comprise areas of conductive material. The sensors Sl-12 are provided under the skin membrane 30 such that there is no gap between the sensor surface and the skin membrane 30. All the sensors and the tabs of conductive material 39a,b are mounted onto a single flexible printed circuit board (PCB) 45 to form a sensor membrane as shown in Figure 7. In Figure 7, the PCB 45 is shown resting on a planar surface. However, the layout of the PCB 45 has been designed such that, when the PCB 45 is lain over the three dimensional contours of the manikin 20 and its case 12, each of the sensors Si- 12, SW1-4 may be correctly positioned as shown in Figure 8. Referring to Figure 8, the sensors comprise 11 capacitive sensors Sl-11. The sensor Si, which is located in the dummy AED controller 60, is for detecting the position of the AED slide switch 62a. Referring to Figures 10(a-b), it is mainly the close presence of a tab of conductive material (not shown) on the underside of the cover member 62b which is in register with the sensor Si which is detected in the extended position of Figure 10(a). The sensor S2, which is located in the flap 16 in or around the recess where the dummy telephone 60 is housed, is for detecting the presence of the dummy telephone 60 in the recess. In the case of sensor S2, it is mainly the close presence of a tab of conductive material (not shown) in the dummy telephone 60 which is detected by the sensor S2. The sensor S3 is for detecting the close presence of a dummy defibrillator pad at the shown location on the left side of the torso 24. The sensor S4 is for detecting the close presence of the user's hand at the shown location on the chest plate 28. The sensor S5 is for detecting a dummy defibrillator pad on the shown location on the right side of the torso 24. The sensor S6 is for detecting the close presence of the user's hand at the shown location on the left shoulder. The sensor S7 is for detecting the close presence of the user's hand at the shown location on the right shoulder. The sensor S7 is also for detecting a dummy defibrillator pad. Thus, the signals from both S5 and S7 may be used in combination to determine the position of the right defibrillator pad. The sensor S9 is for detecting the close presence of the user's hand on the chin region. The sensor S10 is for detecting the close presence of the user's hand on the forehead. The sensors S8,S11 are for detecting the orientation of the head 26. In the case of sensor S8, it is the close presence of the tab of conductive material 39a that signals when head- tilting has started. In the case of sensor Sll, it is the close presence of the tab of conductive material 39b that signals when a predetermined tilting orientation of the head 26 is reached. Referring to Figure 5, the sensors further comprise an accelerometer sensor S12 which provides a signal indicative of the acceleration that it experiences during cardiac massage; that signal is used to calculate the instantaneous depth of compression of the chest region during cardiac massage. Instead of an accelerometer, a HAL effect sensor could be used. The HAL effect sensor measures the distance to a reference magnet 46 located within the cavity 27 of the torso 24. The reference magnet 46 is located at a distance of 6cm below the HAL effect sensor when the torso 24 is in its at-rest Figure 5 position. In correct use, the chest region should not be compressed by more than 6cm. In case of over vigorous chest compression, the magnet 46 is suspended on a spring 47 so that it can recover from any disturbance in its position. The sensor S12 also detects when the lung-bag 31 is inflated since it is displaced upwardly by inflation of the lung- bag 31. The surface area of the sensors Sl,S2 may be smaller than for the sensors that detect hands. In some embodiments, the sensors Sl,S2 may have a surface area of at least 100mm ² , for example, 10mm x 10mm. In some embodiments, the sensors that detect hand may have a surface area of at least 400mm ² , for example, 20mm x 20mm.

The sensors further comprise 4 switches. The switch SW1 is a switch on the dummy AED controller 62 for administering an electric shock. The switch SW2 is a switch on the dummy AED controller 62 for switching on the power to the dummy AED. The switches SW3,4 are located in the lid. The switch SW3 is to be activated by the user as indication that the immediate surroundings of the victim have been checked for safety. The switch SW4 is to be activated by the user as an indication that other people in the immediate vicinity have been warned. Optionally, there may be further switches under the knee pads 15a,b for detecting the presence of the user kneeling on the lid 14. From the foregoing, it will be appreciated that the placement of all the sensors onto a single flexible PCB results in a system which is easy and hence cheap to manufacture. The sensor may for instance be a capacitor having one, two or more capacitive members (capacitor electrodes). In Figure 12, an example of a capacitive member having two electrodes 78, 79 under a skin membrane 30, of which a first electrode 78 is connected to the capacitance measuring circuit 53 and the second connector is connected to ground 75. The near presence of a finger 77 influences the capacitance of the capacitor, which can be detected, by the capacitance measuring circuit 53. Also, the sensor can sense the presence of a dummy electrode of the training AED in the same manner. The capacitor electrodes may also be arranged in mutually spaced layered configuration. If the outer electrode is connected to ground, this provides shielding of the electrode connected to the capacitance measuring circuit against electric disturbances.

Referring to Figure 9, in a preferred embodiment of the invention, the intelligence for performing the training and/or testing resides in a master controller 52, preferably in the form of a PC including a display, which is separate from the manikin 20. The master controller 52 connects to a local controller 50, in the form of a microcontroller, mounted on the flexible PCB 45 via a USB connection 51. In order to minimise the cost of the manikin 20, the role of the local controller 50 is confined to collecting data samples from the sensors Sl-12, SW1-4 and relaying those samples as data streams to the master control 52 over the USB connection 51. The system 10 is powered only via the USB connection and the approximate power consumption is lOOmAh.

The local controller 50 takes measurements from each of the sensors. The local controller 50 is coupled to the switches SW1-4 so as to be able to read their state. The local controller 50 is coupled to the accelerometer sensor S12, via an analogue-to-digital converter (not shown), so as to obtain a digital signal indicative of the acceleration that the sensor S12 is being subjected to. Based on that digital signal, the local controller 50 calculates an instantaneous depth of the compression of the chest region. The system 10 further comprises a capacitance measuring circuit 53, which under the control of the local controller 50, is selectively connectable to each of the sensors Sl-Sll and operable, in a measurement operation, to measure the time taken to charge the sensor from ground to a predetermined voltage. The time taken to so charge a sensor is indicative of the capacitance that it presents to the capacitance measuring circuit 53. It will be appreciated that when the user's hand, a dummy defibrillator pad or any other foreign object moves into close presence with a capacitive sensor Sl-Sll, the effective circuit that is presented to the

capacitance measuring circuit 53 is one in which the capacitance changes but the resistance does not change. For reasons of cost, it is preferred that the local controller 50 comprises a relatively low-end processor. The use of a low-end processor prevents the simultaneous measurement of all the sensors. In one embodiment, the capacitance measuring circuit 53 is selectively connectable to each of the sensors Sl-Sll such that each sensor may be individually measured in sequence. In a preferred embodiment, the capacitance measuring circuit 53 is selectively connectable to each of the sensors Sl-Sll such that selected groupings of the sensors, preferably each grouping comprising 2 or 3 sensors, are measured in sequence. In the latter case, the sensors within a grouping, since they are being measured simultaneously, are selected to be sufficiently remote from one another such that there is no mutual interference. The local controller 50 takes the above measurements at a rate of 1kHz and conveys those measurements to the master controller 52 for further processing. When a given capacitive sensor Si- 11 is not being measured, it is grounded so as to enable the discharge of the charge accumulated in the last measuring cycle. Although the capacitance sensors Sl-Sll are solely measuring capacitance changes, they can exhibit a pseudo force sensitive response. This is because, as a finger, for example, is pressed against the skin membrane 30 adjacent a sensor, the small air gap between the finger and skin membrane 30 becomes smaller, and the area of contact between the finger and the skin membrane 30 gets larger with increased pressing; furthermore, with increased pressing, the volume of the finger (in contact with the skin membrane 30) may become compressed.

The master controller 52 receives the above raw measurement data and is thereby able to determine the current state in real time of all the sensors of the manikin. Since the changes in capacitance exhibited by the capacitive sensors Si- 11 are characteristic of the foreign body that it is detecting, and small and therefore sensitive to environmental and ageing factors, the master controller 52, for the data stream corresponding to each sensor Sill, performs a clustering algorithm, for example, K-means clustering algorithm. In more detail, for each sensor, after a number of successive samples are gathered, a 2D mean and variance metric is calculated. The mean component is indicative of the measured capacitance and this differs

appreciably depending on whether there is a foreign body in close presence with the sensor or not. The variance component is indicative of the noise present in the signal. The noise level changes when a foreign body approaches the sensor. An edge detection algorithm is used to detect when large fluctuations in the metric occurs. Upon detection of a large fluctuation, the newly measured/calculated 2D metric is added to a first-in-first-out (FIFO) buffer. Every time a 2D metric is added to this buffer the K-means clustering algorithm using a digital filter is executed and fed with the contents of the buffer. As an output, the clustering algorithm generates revised 2D

parameters, comprising a variance and mean parameter, which correspond to the centres of both a "touch" cluster (corresponding to a presence event) and the "non-touch" cluster (corresponding to no presence event). The above-mentioned newly measured/calculated 2D metric is then compared with both clusters. The cluster centre which is closest determines the state of the sensor. It will be appreciated that the FIFO buffer allows the system to adapt to changing environments or to compensate for long-term drift caused by ageing.

In a preferred embodiment, the algorithm is configured to operate with 3 clusters, namely a "non-touch" cluster (corresponding to no presence event), "touch with hand" cluster (corresponding to a presence event involving a hand) and a "touch with pad" cluster (corresponding to a presence event involving a defibrillator pad). The use of such an algorithm permits discrimination between an as-intended presence event and an unintended presence event. For example, in the case of the left shoulder sensor S6, the only correct intended presence event is the presence of a human hand. The presence of a human hand will cause generate data streams that are representative of changes in capacitance which are characteristic of that presence event. If a dummy defibrillator pad were erroneously placed in close presence with the shoulder sensor S6, the data stream that is thereby produced would be quite different in nature and the use of the clustering algorithm would reveal it as such.

Initial data sets for each of the sensors may be pre-programmed into the local controller 52 or learned during a set-up phase during manufacture. In use, the manikin 20 can be transported conveniently in the case 12 to the training and/or testing venue. At the venue, the manikin 20 can be deployed into its operational position as shown in Figure 1 and connected to a locally available PC via the USB connection 51. The PC is installed with the training and/or testing software. In a training mode, a user is taken through the protocols for CPR and the use of an AED by the software with the display of the PC providing the text and diagrammatic instruction necessary for the user to learn the skills. Since the PC is provided with the current state in real time of all the sensors Sl-11, SW1-4, the software is able to evaluate the actions of the user and interactively provide corrective feedback via its display. Similarly, in a test mode, the user is requested to carry out the learned protocols via the display of the PC. Again, since the PC is provided with the current state in real time of all the sensors Si- 11, SWl-4, the performance of the user can be evaluated to determine whether the protocols have been adequately performed.

As the protocol for CPR and the use of an AED are generally known, a full explanation will not be given here. A few selected aspects of the protocols are discussed by way of further illustration.

a) Shaking of the shoulders

This action is performed in order to check for consciousness. In this action, the master controller 52 checks that the shoulder sensors S6,S7 are producing data streams indicative of a user's hands. During training, the user is instructed to apply the shaking for a certain duration. During testing, the user is evaluated on whether the shoulder sensors S6,S7 registered the intended proximity event, i.e. the placement of hands, at the required stage in the protocol and for a sensible duration. b) Alert environment

This action is performed in order to alert bystanders. In this action, the master controller 52 checks that the switch SW4 is activated. During training and testing, this action is taken as a substitute or proxy for actual alerting of the environment. c) Check breathing

In this action, the master controller 52 checks that the forehead and chin sensors S9 and S10 are producing data streams indicative of the close presence of a user's hands and that the first and second chin-lift sensors S8,S11 are producing data streams indicative that the head is correctly tilted (thereby clearing the airways in a real patient). During testing, the user is evaluated on whether the required combination of hand placement on the sensors S9, S10 produces sufficient head tilting at the required stage and for a sensible duration. d) Call emergency number

This action is performed in order to enlist professional help. In this action, the master controller 52 checks that the S2 is producing a changed data stream indicating that the telephone 60 has been picked up from the flap 16 and is thus remote from the sensor S2. During training or testing, this action is taken as a substitute or proxy for placing a call to the emergency services. e) Heart massage

In this action, the master controller 52 checks that the chest bone sensor S4 is producing a data stream indicative of a user's hands and in parallel monitors the degree of depression of the chest by the HAL sensors S12. Since the data from the HAL sensor S12 is delivered very frequently, the master controller 52 is able to evaluate the rhythm of the heart massage. f) AED The AED device may be used in a fully-automatic mode or a semi-automatic mode. In the fully-automatic mode, the AED device need only be switched on; if it is needed to apply a shock, the device provides a warning that the shock will be applied and for the user to position himself/herself safely. In the semiautomatic mode, the user additionally needs to apply the shock by depressing the shock switch SW1. The mode is governed by the AED slide switch 62a.

Taking the semi-automatic mode as an example, the AED device is placed into the semi-automatic mode by sliding the cover member 62b into its withdrawn Figure 10(b) position. This position is detected by means of the sensor Si. Then, the master controller 52 checks that the AED power switch SW2 is turned on at the correct moment. Next, the master controller 52 checks that a pair of dummy defibrillator pads (not shown) are attached correctly using the left-side AED sensors S3 and the right-side AED sensor S5 (and possibly sensor S7). The dummy defibrillator pads are preferably made from a conductor such as aluminium in order to cause the maximum change in capacitance of the sensors. In other respects, the defibrillator pads have no further functionality lacking any current delivering or voltage applying capability at all. Finally, the master controller 52 checks that a defibrillation shock is applied by activation of the shock switch SW2. It will be appreciated that by location the intelligence for performing the training and/or testing, and the main data processing functions in a PC remote from the manikin, the hardware requirements for the manikin 20 can be kept low, thereby keeping the manufacturing cost of the manikin 20 low. In other embodiments, the software for directing the training or testing or the above- mentioned data processing functions may be performed locally on the local controller 50. In other embodiments, the software for directing the training or testing may be directed by a remote server located in the internet.

In a further embodiment shown in Figures ll(a-d), the case 20 can be omitted and replaced by a foldable skillstation 70. This further embodiment is identical to the above-described embodiments except in the respects apparent

from Figures ll(a-d) and as explicitly stated below. Although not visible in Figures ll(a-d), the skillstation comprises the local controller 50. The skillstation 70 may be unfolded from its Figure 11(a) condition to its Figure 11(b) condition ready for use. The skillstation 70 comprises the knee pads 15a, 15b for the user to kneel upon during use, and dummy CPR and

AED paraphernalia, including the dummy telephone 60 and the dummy AED controller 62. As illustrated in Figure 11(c), the AED controller 62 may be detachable from the rest of the skillstation 70. The skillstation 70 also comprises dummy defibrillator pads 64a, 64b as shown in Figure 11(c). Figure 11(d) shows the further embodiment ready for use. It will be noted that the skillstation 70 is provided with a USB connection 72a via which the local controller 50 communicates with the main controller/PC 52 and a USB connection 72b (Figure 11(c)) via which the AED controller 62 may be electrically coupled to the rest of the skillstation 70. The PCB 45 and the local controller 50 are electrically connected via a connection 74. In other

embodiments, the local controller 50 may be located on the PCB 45.

As the Figure 11(d) illustrates, using a PC as the main controller 52 enables its graphics capabilites to be harnessed and the user's main attention can be focused on the image present on the display of the PC 52, whereby at least in terms of appearance the manikin need only be a crude physical proxy for a human, or even a human-like robot.

List of parts

AED slide sensor Si

Telephone sensor S2 Left-side AED sensor S3

Chest bone sensor S4

Right-side AED sensor S5

Left shoulder sensor S6

Right shoulder sensor S7 First chin-lift sensor S8

Chin sensor S9

Forehead sensor S10

Second chin-lift sensor Sll

Accelerometer/HAL sensor S12 Shock switch SW1

AED power switch SW2

Check environment switch SW3

Warn other people switch SW4 System 10

Case 12

Base 13

Floor 13a

Lid 14 Inner surface 14a

Knee pads 15a,b

Flap 16

Hinge portion 16a

Manikin 20 Body 22

Torso 24 Air-bag 25

Head 26

Mouth opening 26b

Cavity 27

Chest plate 28

Reinforcement ribs 28a

Skin membrane 30

Lung-bag 31

Head assembly 32

Neck part 33

Support struts 33a,b

Chin part 34

Side portions 34a,b

Bridge portion 34c

Arms 35a,b

Springs 36a,b

First surfaces 37a,b

Second surfaces 38a,b

Tabs of conductive material 39a,b

Mouth part 40

Lung-bag connector 41

Wing portions 42a,b

Tab 43

Nose part 44

PCB 45

Magnet 46

Spring 47

Local controller/microcontroller 50

USB connection 51

Master control/PC 52

Capacitance measuring circuit 53 Telephone 60

AED controller 62

AED slide switch 62a

Cover member 62b Defribillator pads 64a,b

Skillstation 70

USB connections 72a,b

Connection 74

Ground 75 Finger 77

Electrode 78

Electrode (ground) 79