GB2569157A

GB2569157A - Medical device, wearable device, alert device and methods

Info

Publication number: GB2569157A
Application number: GB1720419.9A
Authority: GB
Inventors: James Colin Webb Kristian; Christopher Phillips Patrick
Original assignee: Lois Medical Ltd
Current assignee: Lois Medical Ltd
Priority date: 2017-12-07
Filing date: 2017-12-07
Publication date: 2019-06-12
Also published as: GB201720419D0; WO2019110963A1

Abstract

A wearable device 403 such as a smart watch receives a signal from an implant 401, such as an implantable cardioverter defibrillator (ICD), in response to a predetermined physiological event such as an abnormal arrhythmia indicative of cardiac arrest. Upon receipt, the wearable device transmits an alert signal 404 to one or more alert devices, such as at a hospital or monitoring service or the device of a friend or relative, via communications network e.g. LAN, Wi-Fi (RTM) or Bluetooth (RTM). The signal from the implanted device may be a high voltage electric shock generated by an ICD for alleviating cardiac arrhythmia, and may be transmitted to the wearable device via organic tissue of the wearer. A wireless signal may be used instead. Associated data such as patient name, location via location circuitry, treatment applied e.g. number of shocks and the result of treatment e.g. “unsuccessful”, may also be transmitted.

Description

(57) Awearable device 403 such as a smart watch receives a signal from an implant 401, such as an implantable cardioverter defibrillator (ICD), in response to a predetermined physiological event such as an abnormal arrhythmia indicative of cardiac arrest. Upon receipt, the wearable device transmits an alert signal 404 to one or more alert devices, such as at a hospital or monitoring service or the device of a friend or relative, via communications network e.g. LAN, Wi-Fi (RTM) or Bluetooth (RTM). The signal from the implanted device may be a high voltage electric shock generated by an ICD for alleviating cardiac arrhythmia, and may be transmitted to the wearable device via organic tissue of the wearer. A wireless signal may be used instead. Associated data such as patient name, location via location circuitry, treatment applied e.g. number of shocks and the result of treatment e.g. “unsuccessful”, may also be transmitted.

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MEDICAL DEVICE, WEARABLE DEVICE, ALERT DEVICE AND METHODS

BACKGROUND

Field of the Disclosure

The present invention relates to a medical device, wearable device, alert device and methods.

Description of the Related Art

The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in the background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.

As medical devices have improved in recent years, it is now possible for such devices to be implanted inside the body of a user so as to detect certain abnormalities in the physiological function of that user’s body and, in some cases, to perform corrective action in response to detecting such an abnormality. An example of such a medical device is an implantable cardioverter defibrillator (ICD). ICDs are defibrillators designed to treat a cardiac arrest in patients that have, for example, either survived a previous cardiac arrest or patients who have a heart condition that increases the risk of a cardiac arrest occurring. ICDs have the ability to treat a cardiac arrest by converting a dangerous arrhythmia of the heart with a high energy electrical impulse (otherwise known as an electric shock). During the shock, the patient will either experience a large “kick” to the chest (if conscious) or will be unaware of the therapy (due to a loss of consciousness).

Implantable medical devices such as ICDs provide a very fast response to physiological abnormalities in a user which, if left untreated, may result in the patient becoming very unwell (perhaps even fatally). A problem, however, is that although, although medical devices such as ICDs are able to instantly attempt to treat a physiological problem such as a cardiac arrest (following a therapy provided by the device) it is usually still necessary for the user concerned to take action to inform others of the event and/or to alert a doctor or other healthcare professional in order to allow the cause of the abnormal physiological behavior to be investigated and to determine whether ongoing treatment needs to be introduced or reviewed in order to reduce the risk of the physiological abnormality happening again. In addition, it can be the case that, despite treatment administered automatically by the implanted medical device, the physiological abnormality may not be sufficiently treated by the implanted medical device. For example, an ICD, despite providing several shocks to a user, may not be able to effectively treat a dangerous arrhythmia.. In this case, the patient will often be unable to seek help (due to loss of consciousness, for example). Such a situation is particularly dangerous if the patient is alone (since if external help by a third party is not received, the patient is likely to experience a fatal cardiac arrest).

Medical devices such as ICDs have been introduced which are configured to communicate with a base station positioned in the home of the wearer. Such systems are designed to flag any abnormalities and to reduce the number of outpatient appointments the patient has to attend. The base station receives wireless signals (e.g. radio signals) from the medical device implanted in the patient’s body and, in turn, forwards the signals (e.g. over the internet) to a healthcare provider. . The data extracted from the implanted device and transmitted by the home base station is determined according to a preset specification. This nominally includes device settings, device function, measurements, physiological abnormalities and any therapies that have been administered.. For example, in the case of an ICD, the ICD may transmit signals to a home base station indicating the current cardiac rhythm of the wearer and data on any previous rhythm abnormalities and any electric shocks provided by the ICD to treat dangerous arrhythmias.

A problem with such existing systems, however, is that the data fed to the system of a hospital or healthcare professional by the base station is merely a data recording tool which becomes associated with a patient’s medical record or the like. That is, although data is received from a medical device such as an ICD implanted in the body of the patient, this data is used to monitor a patient’s condition generally and to help guide the specifics of ongoing treatment of the patient. Thus, if, for example, the patient is suffering a cardiac arrest which cannot be successfully treated by an implanted medical device such as an ICD, a doctor or other healthcare professional will not know this unless the medical records of the patient are accessed manually. Typically, manual access of a patient’s medical records including received medical device data is not carried out as a matter of routine but, rather, is accessed when providing treatment or check-up appointments to the patient. Thus, the fact that a patient has suffered a potentially fatal physiological abnormality such as a cardiac arrest will not be known by anyone until the patient’s medical records are checked. If the patient has not been able to seek help themselves (e.g. if they are alone in their home and are physically unable to call for help), then it may be too late to save the patient’s life. Another problem associated with current systems is that they will only work when the user is in their home. This is because of the need for signals transmitted by implanted medical devices such as ICDs to be transmitted to a hospital or healthcare provider via a base station installed in the home.

There is a need to alleviate the above-mentioned problems.

SUMMARY

The present technique is defined by the claims.

The foregoing paragraphs have been provided by way of general introduction, and are not intended to limit the scope of the following claims. The described embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

Figure 1 schematically shows a system according to an embodiment of the present technique; Figures 2A and 2B each schematically illustrate an example of information displayed by an alert device;

Figure 3 schematically shows a first example of the present technique according to an embodiment;

Figure 4 schematically shows a second example of the present technique according to an embodiment;

Figures 5A and 5B schematically show, respectively, a transmitter of an implanted medical device and a receiver of a wearable device, according to an embodiment;

Figure 6 schematically shows a sequence of events when the present technique is used with an implanted cardioverter defibrillator, according to an embodiment;

Figure 7 schematically shows a method of operating a wearable device according to an embodiment;

Figure 8 schematically shows a method of operating an implanted medical device according to an embodiment; and

Figure 9 schematically shows a method of operating an alert device according to an embodiment.

DESCRIPTION OF THE EMBODIMENTS

Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views.

Figure 1 shows a system according to an embodiment of the present technique. The system comprises a medical device 106 which is implantable in the body of a user, a wearable device

100 which is wearable by the user (for example, as a bracelet on a wearer’s wrist or ankle, a ring on the user’s finger, an item of clothing warn by the user or an adhesive patch adhered to the user’s skin), and a plurality of alert devices 110A and 110B. In other embodiments, it will be noted that there may be only one alert device.

The medical device 106 is a device such as an ICD which is implantable in a body of a user (the user is not shown in Figure 1). The medical device 106 comprises a detector 107 configured to detect, when the medical device is implanted in the user’s body, a predetermined physiological event (such as an abnormal arrhythmia indicative of a potential cardiac arrest). The medical device may operate any known technology for detecting the predetermined physiological event concerned. The technology associated with detecting predetermined physiological events such as cardiac arrests is well known and therefore will not be described in detail here. An example of an ICD that implements such technology and which may be used with embodiments of the present technique is the Medtronic ® Visia ICD.

The medical device 106 also comprises a transmitter 108 configured to transmit, in response to the detector 107 detecting a predetermined physiological event, a signal to the wearable device 100 worn by the user. The transmission of the signal from the transmitter 108 of the medical device 106 to a receiver 101 of the wearable device 100 is shown by arrow 119. The operation of the detector 107 and transmitter 108 is controlled by the controller 109. Each of the detector 107, transmitter 108 and controller 109 may be implemented using circuitry, for example. In particular, the controller 109 may comprise processing circuitry for processing instructions to control the detector 107 and transmitter 108.

The wearable device 100 comprises a receiver 101 configured to receive the signal transmitted by the transmitter 108 of the medical device 106. The wearable device 100 also comprises a transmitter 102 configured to transmit, in response to the receiver 101 receiving the signal from the implanted medical device 106, alert information to one or more of the alert devices 110A and 110A for alerting a person other than the wearer of the wearable device of the occurrence of the predetermined physiological event detected by the detector 107 of the medical device 106. The wearable device 100 also comprises location circuitry 104 for determining a position of the wearable device (and therefore of a user wearing the wearable device). The wearable device also comprises a storage medium 125 (comprising semi-conductor memory, for example) for storing digital information. Each of the receiver 101, transmitter 102, location circuitry 104 and storage medium 125 are controlled by a controller 103. Each of the receiver 101, transmitter 102, controller 103 and location circuitry 104 may be implemented as circuitry, for example. In particular, the controller 103 may comprise processing circuitry configured to process instructions for controlling the receiver 101, transmitter 102, location circuitry 104 and storage medium 125.

The alert device 110A comprises a receiver 111 configured to receive, from the wearable device 100, alert information, the alert information being transmitted by the transmitter 102 of the wearable device 100 in response to the wearable device 100 receiving the signal transmitted along arrow 119 by the transmitter 108 of the medical device 106. In this example, the alert information transmitted to the alert device 110A is transmitted via a communications network 105 according to the arrows 120 and 121. In embodiments, the communications network 105 may be the internet, for example. The alert device 110A also comprises information output circuitry 112 configured, in response to the receiver 111 receiving the alert information, to output information indicative of the occurrence of the predetermined physiological event to a person other than the user wearing the wearable device 100. In this example, the output information is output to a display 114 (such as a liquid crystal display (LCD) or the like) which is separate to the alert device 110A (e.g. the display 114 may be a display of a separate computer monitor). The wearable device also comprises a storage medium 126 (comprising semi-conductor memory, for example) for storing digital information The receiver 111, information output circuitry 112 and storage medium 126 are controlled by a controller 113. Each of the receiver 111, information output circuitry 112 and controller 113 may be implanted using circuitry, for example. In particular, the controller 113 may comprise processing circuitry configured to process instructions for controlling the receiver 111, information output circuitry 112 and storage medium 126. In one example, the alert device 110A is a computer located at the premises of a healthcare provider (such as a clinic, hospital, monitoring service or insurance provider). The received alert information may therefore be used by the information output circuitry 112 to generate output information for display on the display 114 for alerting a healthcare professional (such as a doctor or nurse) of information associated with the predetermined physiological event detected by the medical device 106.

The alert device 110B has similar functionality to the alert device 110A. In particular, the alert device 110B comprises a receiver 115, information output circuitry 116 and a controller 117 which operate in the same way as the receiver 111, information output circuitry 112 and controller 113 of the alert device 110A. However, this time, a display 118 (such as an LCD display or the like) is comprised as part of the alert device 110B. The alert device 110B may therefore be a terminal device such as a mobile phone, tablet computer, laptop computer or the like which comprises a built-in display 118. In the case of the alert device 110B, the receiver 115 receives the alert information from the wearable device 100 over the network, as indicated by arrows 120 and 122. The alert device 110B may be a terminal device owned by a person (such as a friend or relative) previously chosen by the wearer of the wearable device 100 (that is, chosen in advance) so as to enable them to be alerted of any predetermined physiological event detected by the medical device 106.

In the example of alert device 110B, alert information received at the receiver 115 is used by the information output circuitry 116 to generate output information for display on the display 118 to alert the chosen person in the event of a predetermined physiological event occurring. For example, the terminal device may be owned by a friend or relative of the wearer who has been chosen by the wearer to be alerted in response to the occurrence of the predetermined physiological event. It will be appreciated that there may be more alert devices than the alert devices 110A and 110B shown in Figure 1. It will also be appreciated that the route through which alert information is transmitted through the network 105 may be different to that shown.

For example, the alert information may initially be transmitted from the transmitter 102 of the wearable device 100 to the first alert device 110A via the arrows 120 and 121. The alert information (which may be edited by the alert device 110A) may then be transmitted to the alert device 110B (for receipt at the receiver 115 of the alert device 110B) instead of the alert information being directly transmitted to the alert device 110B from the wearable device 100. Such a scenario may be appropriate when, for example, the alert device 110A is comprised as part of a central server located at the premises of a healthcare provider such as a clinic or hospital and the alert device 110B is a terminal device of a friend or relative of the wearer of the wearable device 100. In this case, the alert information indicating that the predetermined physiological event detected by the medical device 106 has occurred is first received by the healthcare provider so that they may begin taking appropriate action, such as asking the wearer of the wearable device 100 (who is also the user within whose body the medical device 106 has been implanted) to attend an appointment for a check-up or, in more serious cases, to call an ambulance or the like so as to provide emergency treatment to the wearer of the wearable device 100. The alert information is then forwarded to the alert device 110B (e.g. via the network 105) in order to alert the friend or relative that the predetermined physiological event has occurred and that the wearer of the wearable device 100 (who may be referred to as the patient) is now being provided with assistance.

It will be appreciated that other configurations for the transfer of information between a plurality of alert devices such as 110A and 110B may be implemented. In any case, it will be appreciated that a receiver of an alert device (such as receivers 111 and 115 of alert devices 110A and 110B, respectively) is able to receive alert information either directly from the wearable device 100 over the network 105 or, alternatively, may receive the alert information from another alert device which has previously received the alert information directly from the wearable device 100 over the network 105. The alert information forwarded from a first alert device 110A to a second alert device 110B is based on the alert information received from the wearable device 100. For example, in the case that alert information is received from the wearable device 100 by an alert device 110A comprised within a hospital or clinic, the alert information may comprise information indicating that a cardiac arrest has occurred, together with other information such as how long the cardiac arrest has been occurring for, the number of shocks that have been output by the medical device 106 (in this case, an ICD), the intensity of each shock (e.g. the electrical energy delivered to the patient during each shock, in joules) and any other relevant information associated with the cardiac arrest and the treatment which has been applied by the medical device 106. This detailed information is appropriate for a doctor or healthcare professional, but not necessarily appropriate for a friend or relative of the patient (who may not be medically trained and who therefore may not understand the detailed information provided as part of the alert information). The alert information forwarded to the alert device 110B may therefore be edited by the controller 113 of the alert device 110A prior to the alert information being forwarded in order to make the information displayed on the display 118 of the alert device 110B more appropriate. For example, in the case that the alert information is to be forwarded to the alert device of a relative or friend of the patient (who may not be medically trained and may therefore not understand detailed medical information), the alert information may be simplified prior to being forwarded so as to only include key details which are more understandable to a non-professional. For example, the output information may simply indicate that a cardiac arrest has occurred and that treatment administered by the medical device 106 has failed, without providing specific technical details of the cardiac arrest (as detected by the medical device 106) or the treatment provided (such as the frequency and energy of shocks provided by the medical device 106). The forwarded alert information may also include additional information such as the action taken by the healthcare provider (e.g. information indicating that an ambulance is on its way to the patient). The alert information transmitted by the wearable device 100 may therefore be edited (e.g. amended, reduced or expanded) before being forwarded from one alert device 110A to another alert device 110B in accordance with the intended audience of the alert information. The alert information (whether or not it has been edited) is transmitted from a transmitter 123 comprised within the alert device 110A to the receiver 115 of the alert device 110B in the direction shown by arrow 124. Although not shown (for the sake of clarity of Figure 1), the alert information may be transmitted from the alert device 110A to the alert device 110B via the network 105. The transmitter 123 may be implemented as circuitry and is controlled by the controller 123. The receiver 111, transmitter 123, controller 113 and storage medium 126 of the alert device 110A allow the alert device 110A to act as a server in the system shown in Figure 1, the alert device 110A managing the distribution of alert information transmitted to it from the wearable device 100 over the network 105 to other alert devices (such as alert device 110B). The alert device 110A may perform other functions of a server, such as storing information in the storage medium 126 (such as information associated with the patient 300 wearing the wearable device) for use in editing alert information before it is forwarded to another alert device and routing alert information to the correct one or more wearable devices (for example, information indicative of one or more alert devices such as alert device 110B belonging to previously chosen friends or relatives of the patient may be stored in the storage medium 126).

Figures 2A and 2B illustrate an example of the information displayed by an alert device 110A (e.g. located at a hospital) and the information output by an alert device 110B (e.g. a mobile phone of a friend or family member of the patient) in response to the occurrence of a predetermined physiological event detected by the medical device 106. In the examples of Figures 2A and 2B, the medical device is an ICD which detects and attempts to treat a cardiac arrest.

Figure 2A shows a display 114 displaying information output by the information output circuitry 112 in response to alert information being received by the receiver 111. The output information comprises information indicating the predetermined physiological event which has been detected. This is the information 200. In this case, the detected physiological event is a cardiac arrest. Also output is the patient’s name 201, the current location of the patient 202 (as determined by the location circuitry 104 of the wearable device 100, for example), a duration of the cardiac arrest 203 (as measured by the detector 107), the treatment applied 204 (in this case, that three electric shocks have been provided to the user, each of these having an energy of 35 joules and each shock being 60 seconds apart), an outcome of the treatment 205 (which in this case, is “unsuccessful” - that is, the cardiac arrest has not been alleviated by the shocks) and a recommend action 206 (which, in this case, is for an ambulance to be called to the patient’s location). Each of these pieces of information is comprised within the received alert information and is displayed as part of an image 208 displayed on the display 114. In addition, a virtual button 207 is also displayed as part of the image 208. The virtual button is selectable by a viewer of the display 114 (in particular, a doctor or other healthcare professional working at the hospital at which the alert device 110A is located) in order to initiate the forwarding of the alert information to the alert device 110B held by the friend or relative of the patient. The viewer of the display 114A selects (that is, operates) the virtual button 207 via any suitable user interface (not shown) of the alert device 110A, such as a mouse, keyboard, touchscreen or the like.

In response to the selection of the virtual button 207, the alert information is forwarded to the alert device 110B (e.g. via the network 105). In response to the receiver 115 receiving the alert information, information indicating the occurrence of the cardiac arrest 209, more detailed information about the patient 210 (in particular, the patient name and the action taken so far, namely that an ambulance is on its way) and a telephone number 211 are provided as part of an image 212 displayed on the display 118 of the alert device 110B. This information alerts the friend or relative previously chosen by the patient to be alerted in the case of a cardiac arrest to be notified that the cardiac arrest has occurred, some essential information regarding who has suffered the cardiac arrest, what action has been taken and what to do next (in this case, to call the given telephone number 211). In this case, the alert device 110B is a smartphone of the friend or relative of the patient.

In the above example, by the doctor (or other healthcare professional) selecting the virtual button 207, it is assumed that the recommend action of calling an ambulance has been carried out. This is why the information 210 displayed on the display 118 of the alert device 11 OB indicates that an ambulance is on its way. In other embodiments, it would be appreciated that the operator of the alert device 110A may edit the message to be displayed to the user of the alert device 110B prior to the alert information being forwarded to the alert device 110B. This allows a doctor or other health care professional to provide any further information which might be useful or relevant to the viewer of the alert device 110B (in this way, the doctor is able to edit the alert information before it is forwarded to the alert device 11 OB).

It will thus be appreciated that, generally, the alert information transmitted by the transmitter 102 of the wearable device 100 may be used by one or more alert devices (such as alert devices 110A and 110B) in any number of ways. Generally, the alert information is information for alerting a person other than the patient of the occurrence of a predetermined physiological event such as a cardiac arrest as detected by an ICD. This alert information may then be used in different ways by different respective alert devices. Furthermore, the alert information may be transmitted to one alert device via another alert device so as to enable the distribution of the alert information to be controlled and to enable the alert information to be amended (e.g. by the removal or addition of certain details) depending on the type of user of the alert device to which the alert information is to be forwarded. Alternatively, each alert device may be provided with the same alert information via the network 105 and a controller of each respective alert device may then control the information output to the user of that device based on the received alert information and on the type of user (e.g. professional or non-professional) of that alert device.

It will thus be appreciated that each alert device may receive alert information directly from the wearable device 100 over the network 105 or, alternatively, may receive alert information from another alert device. The alert information may be amended by the transmitting alert device prior to the alert information being transmitted to the receiving alert device so as to enable information appropriate to the user of each respective alert device to be displayed on that device. As long as the amended alert information still comprises information for alerting a user of each respective alert device of the occurrence of the predetermined physiological event (such as a cardiac arrest in the example of Figures 2A and 2B), then the purpose of the alert information is conserved. That is, information transmitted to one alert device from another alert device remains alert information as long as the information is for alerting each user of the respective one or more receiving alert devices of the occurrence of the predetermined physiological event detected by the medical device 106 implanted in the body of the patient.

It will be appreciated that information output by the output circuitry 112 and 116 of the alert devices 110A and 110B, respectively, may be output to another type of device for providing cognitively comprehensible information to a user. For example, instead of or in addition to the output information being displayed on a display (such as an LCD display or the like), the information may be output by a sound processor and loudspeaker (not shown) in order to alert the user of a particular alert device of the occurrence of the predetermined physiological event detected by the medical device 106.

In the example of Figure 1, the receiver 115 of the alert device 110B may be configured to receiver alert information both directly from the wearable device 100 (via the path indicated by arrows 120 and 122) and via the alert device 110A (as indicated by the arrows 120, 121 and 124). Such an arrangement allows the user of the alert device 110B to be immediately notified of the occurrence of the predetermined physiological event detected by the medical device 106. Further information (e.g. that an ambulance has been called) may then be received at a later point from the alert device 110A, thus providing the user of the alert device 110B with more comprehensive information about the predetermined physiological event and the actions that have been taken. This allows the user of the alert device 110B to be provided with information regarding the occurrence of the predetermined physiological event as soon as that information becomes available. This allows, for example, the user of the alert device 110B to help the patient (if they are near by) prior to being informed by the user of the alert device 110A (e.g. the hospital) that an ambulance is on its way. In this case, different portions of alert information are received at different times from different sources, depending on when and from where that alert information becomes available.

It will be appreciated that each alert device may be implemented using conventional hardware using an appropriate software application or the like. For example, the alert device 110A may be a personal computer located within a hospital or clinic running a software application which controls the personal computer to carry out the functions of the receiver 111, information output circuitry 112, controller 113 and transmitter 123 (where present). Similarly, the alert device 110B may be a terminal device such as a mobile phone, tablet computer or the like running a software application which controls the terminal device to carry out the functions of the receiver 115, information output circuitry 116, controller 117 and display 118. In this case, the software application may be downloaded as an “app” (e.g. as compatible with Android ® devices or iOS ® devices). In such cases, the function of each alert device as described is implemented using the existing communication and processing hardware of the device on which the software application is installed.

In the example of Figures 2A and 2B, in the case that a first instance of alert information is received by the alert device 110B directly from the wearable device 100 and that a second instance of alert information is received, at a subsequent time, from the alert device 110A, it may be the case, for example, that, initially, in response to the receipt of the first instance of alert information, information 209 indicating that a cardiac arrest has occurred, together with the telephone number 211 is displayed on the display 118. Then, at a later time, when the second instance of alert information is received (e.g. after a medical professional operating the alert device 110A has reviewed the information shown in Figure 2A and selected the button 207), further information indicating that an ambulance has been called is displayed on the display 118. It will thus be appreciated that information displayed on the display 118 of the alert device 110B (such as a smartphone of a friend or relative of the patient) may be updated using a plurality of instances of alert information received from different sources (e.g. directly from the wearable device 100 and from another alert device 110A) at different times, depending on when this alert information becomes available.

Figure 3 shows an example of the present technique according to one embodiment. In this case, the medical device 106 is an ICD and the signal transmitted by the medical device 106 in response to detection of a potential cardia arrest in the patient is the electric signal generated as a result of an electric shock given to the patient 300. The transmitter 108 of the medical device 106 is therefore an electrode which delivers the electric shock to the patient 300 in order to attempt to treat the cardiac arrhythmia. Figure 3 shows various events which occur during and following detection of such a potential cardiac arrest. At step 301, the patient experiences a dangerous cardiac arrhythmia indicative of a cardiac arrest. At step 302, in response to the detector 107 of the ICD detecting the dangerous cardiac arrhythmia (according to known techniques in existing ICDs), the ICD delivers a high voltage shock to the chest of the patient 300. The electrical energy resulting from the application of the electric shock travels through the organic tissue (body tissue) of the patient 300 and is detected by the wearable device 100 at step 303 (in particular, the electrical energy is detected by the receiver 101 of the wearable device 100). The signal detected by the receiver 101 is therefore the electrical energy of the applied electric shock which has travelled to the wearable device 100 (in this case, a bracelet worn around the wrist of the patient 300) through the organic tissue of the patient. The receiver 101 therefore comprises a component for detecting the presence of electric energy, for example, a voltmeter which detects the voltage (potential difference) between the patient’s skin and a portion of the wearable device 100 not in contact with the patients skin. In the case that the detected voltage increases by more than a predetermined amount (optionally, within a predetermined time period), the controller 103 determines that a shock has occurred. At step 304, alert information is transmitted to one or more alert devices (such as alert devices 110A and/or 110B). The alert information is transmitted as a wireless signal, in particular, a radio signal. The alert information is then used to alert one or more appropriate persons in the way as previously described.

The alert information in embodiments may be transmitted via any suitable wireless signal to one or more predetermined alert devices.

In one example, the alert information is transmitted to one or more predetermined alert devices via a mobile telecommunications network such as a Long Term Evolution (LTE) network administered by the Third Generation Partnership Project (3GPP). In this case, the wearable device is a terminal device (or user equipment (UE)) which connects to the mobile telecommunications network in accordance with a suitable one or more of the various LTE standards. The wearable device 100 may comprise a Subscriber Identity Module (SIM) card or the like in order to enable it to connect to the mobile telecommunications network. In this case, the network 105 comprises the mobile telecommunications network so as to enable the alert information transmitted by the wearable device 100 to be received by an appropriate alert device (such as one or both of alert devices 110A and 110B).

In another example, the wearable device 100 may transmit the alert information via a connection a Local Area Network LAN (e.g. a Wireless Local Area Network WLAN such as a Wi-Fi ® network). Again, in this case, the network 105 will comprise the LAN so as to enable the alert information to be transmitted to an appropriate one or both of the alert devices 110A and 110B.

It will be appreciated that the transmission of the alert information from the wearable device 100 via a mobile telecommunications network is advantageous in that the alert information may be transmitted from any location within a wide geographical area covered by mobile telecommunications networks. Furthermore, the transmission of the alert information via a local area network (e.g. a Wi-Fi ® network) is advantageous in that it will still be possible to transmit alert information from locations which have no or little coverage of mobile telecommunications networks (such as certain indoor locations). The wearable device 100 (in particular the transmitter 102 of the wearable device) may be configured to transmit the alert information via either a mobile telecommunications network or local area network, depending on which of those networks are available. This allows alert information to be transmitted using the most appropriate network (e.g. the network with the best signal strength or quality) at any given time. This improves the likelihood of the alert information being successfully received by an appropriate alert device in the event of a physiological event such as a cardiac arrest.

By the wearable device 100 detecting the electric signal transmitted through the organic tissue of the user 300 as a result of an electric sock delivered by an ICD, the wearable device 100 may be used with any existing ICD implanted in the patient 300. That is, the patient does not need to have a specific ICD installed in order to benefit from the wearable device 100. Rather, any ICD (which delivers a high voltage shock in the case of a cardiac arrest) will generate (by the action of delivering a high voltage shock) an electric signal which is detectable by the wearable device 100 so as to allow alert information to be transmitted in response to the patient experiencing a cardiac arrest. The wearable device 100 may therefore work with any ICD without the need for a specific type of ICD to be implanted in the patient 300 and without any extensive configuration on the part of the user. The wearable device 100 is therefore quick and easy to set up.

In addition to an implanted medical device 106 such as an ICD omitting an electrical signal detectable by the wearable device 100 in the case of delivering a shock to the patient 300, it is also envisaged that, instead or in addition to the transmission of such an electrical signal, an implanted medical device 106 may communicate with the wearable device 100 via a wireless signal. Any wireless signal which, when transmitted by the transmitter 108 of an implanted medical device 106, is able to penetrate the organic tissue of the patient 300 so as to be received by the receiver 101 of the wearable device 100 located outside the patient’s body 300 may be used. For example, a radio signal may be used.

Such an arrangement is schematically illustrated in Figure 4, in which a plurality of implantable devices 106 are implanted in the patient 300. In this case, each of the implanted devices 106 is able to transmit (a) an electrical signal to the wearable device 100 via organic tissue of the patient 300, (b) a wireless (e.g. radio) signal to the wearable device 100 or (c) transmit both an electrical signal (via the organic tissue of the patient 300) and a wireless (e.g. radio) signal to the wearable device 100. In this case, the transmitter 108 of each implanted medical display 106 is either a transmitter of an electrical signal, a transmitter of a wireless (e.g. radio) signal or comprises an electrical signal transmission portion and a wireless (e.g. radio) signal transmission portion. An example of this is schematically shown in Figure 5A, in which the transmitter 108 of the medical device 106 comprises a first portion 108A for generating an electric shock (and therefore an electrical signal detectable by the wearable device - although not shown, the first portion 108A will comprise electrodes in contact with organic tissue of the patient’s body) and a second portion 108B for transmitting radio signals. Note that, for the sake of brevity, the other components of medical device 106 are not shown in Figure 5A.

Similarly, the receiver 101 of the wearable device 100 (a) is configured to detect an electrical signal transmitted via the organic tissue of the patient 300 (e.g. by comprising a voltmeter, as previously described), (b) is configured to detect a wireless (e.g. radio) signal transmitted by one or more of the medical devices 106 (e.g. by comprising a radio receiver) or (c) comprises both a wireless (e.g. radio) signal receiving portion and an electrical signal receiving portion. An example of (c) is schematically shown in Figure 5B, in which the receiver 101 of the wearable device 100 comprises a first portion 101A for detecting an electrical signal (for detecting the electric energy of an electric shock provided by the medical device 106, e.g. the first portion 101A may comprise a voltmeter or the like) and a second portion 101B for receiving radio signals. Note that, for the sake of brevity, the other components of wearable device 100 are not shown in Figure 5B.

By allowing an implanted medical device 106 to communication with the wearable device 100 via wireless signals such as radio signals (for example, a medical device 106 and wearable device 100 may be configured to exchange radio signals via a Bluetooth ® or Wi-Fi ® pairing between the medical device 106 and wearable device 100), the wearable device 100 is able to receive more information about the detected predetermined physiological event and any treatment applied compared to the situation of the wearable device 100 receiving an electrical signal (as a result of a shock applied to the patient by an ICD) alone. For example, a wireless signal transmitted from an ICD to the wearable device 100 may comprise additional information relating to the dangerous cardiac arrhythmia which was detected (such as data indicative of an electric cardiogram) which is received by the receiver 100 and transmitted to an appropriate alert device (such as one or both of alert devices 110A and 110B) to provide more information to healthcare professionals about the physiological event which has occurred. It will also be appreciated that, by allowing a wearable device 100 to receive wireless signals transmitted by an implanted medical device 106 in response to a detection by the implanted medical device of a predetermined physiological event, the present technique is not limited to use with medical devices such as ICD’s which, by their very nature, transmit electrical signals of sufficient power such that they are detectable at another part of a patients body (e.g. the wrist, when the wearable device 100 is a wristband). For example, other types of implantable medical device 106 (such as pacemakers, implanted insulin pumps and/or glucose monitors, neuromodulation devices or any other implantable medical device for monitoring and/or treating a particular physiological condition of a patient) may transmit information via a wireless signal to the wearable device 100 so as to enable the physiological condition or event with which that medical device 106 is associated to be monitored by one or more of the patient 300 in which the device is implanted, a healthcare professional and another person nominated in advance by the patient. This allows the wearable device 100 of the present technique to be used with any implantable medical device 106 which is able to transmit information to the wearable device 100 using a wireless signal such as a radio signal.

It is noted that, in embodiments, any wireless pairing (e.g. via Bluetooth ® or Wi-Fi ®) of an implanted medical device 106 and wearable device 100 may be carried out according to any suitable method known in the art. Similarly, the selection of one or more alert devices to which alert information is to be transmitted over the network 105 may be carried out according to any suitable method known in the art. For example, each wearable device 100 and alert device (e.g.

alert devices 110A and 110B) may be associated with unique identifier (such as a media access control (MAC) address) which enables that device to be identified on the network 105. A patient 300 (or authorised third party) may then determine the alert devices which are to be provided with alert information by configuring the wearable device 100 appropriately (e.g. using a user interface (not shown) of the wearable device 100 or the like). Configuring a particular device to communicate certain information to one or more other particular devices via a communications network is known in the art, and will therefore not be discussed in detail here.

As previously mentioned, the alert information may comprise data associated with the predetermined physiological event detected by the implanted medical device 106. This data is based on the signal received from the implanted medical device, whether this signal is an electrical signal (e.g. generated by an ICD delivering an electric shock to a patient 300 who is experiencing a potential cardiac arrest) or a wireless signal such as a radio signal. Examples of the data included in the alert information are discussed with reference to Figures 2A and 2B, for example (e.g. in the case of Figure 2A, the alert information comprised information indicative of the patient name 201, the cardiac arrest duration 203, the treatment applied 204, the treatment outcome 205 and a recommended action to be taken 206). A portion of information comprised within the alert information may be determined by the controller 103 based on the signal received by the receiver 101 from the medical device 106. For example, if the signal is an electric signal resulting from an electric shock applied to the user, then information indicative of the cardiac arrest duration 203 and treatment applied 204 may be determined by the controller 103 based on the received electric signal (e.g. the cardiac arrest duration 203 may be determined from the time duration over which shocks have been applied to the patient 300 and the treatment applied 204 (e.g. number of shocks, time between shocks and the energy of each shock) may be determined based on the number of electric signals detected and their energy). It will be appreciated that even more information to be included in the alert information may be received from the medical device 106 in the case that a wireless (e.g. radio) signal is used to transmit this information from the medical device 106 to the wearable device 100 (wireless signals such as radio signals can carry larger amounts of data than a single electrical pulse resulting from the application of an electric shock to the patient). Alternatively, or in addition, a portion of information comprised within the alert information may be stored in the storage medium 125 of the wearable device. For example, information indicative of the patient name 201 may be stored in the storage medium and included in the transmitted alert information. This information may be the patient name itself, or, alternatively, may simply be a unique identifier of the wearable device (e.g. a MAC address) which enables the patient’s name to be looked up by a server (e.g. alert device 110A, which also functions as a server in some embodiments) of the network 105 in which the patient’s name is stored in advance. The looking up of data at a server based on a unique identifier of a particular hardware device is known in the art, and will therefore not be described in detail here. It is also noted that the storage medium 125 of the wearable device 100 may also store information indicative of the alert devices to which the alert information is to be sent (e.g. the MAC addresses of those devices). Alternatively, in the case that alert information is first transmitted to a server (such as alert device 110A) prior to being forwarded to one or more other alert devices, information indicative of the one or more other alert devices may be stored in storage medium of the server (such as storage medium 126 of alert device 110A).

In general, it will be appreciated that alert information (which, in one embodiment, may simply comprise a signal indicating that the predetermined physiological event has occurred or, in an alternative embodiment, may comprise one or more further types of information associated with the predetermined physiological event, such information being comprised within the signal received by the receiver 101 from the implanted medical device 106 and/or being stored in the storage medium 125 of the wearable device 100) may be combined with any suitable information stored in the storage medium 126 of the alert device 110A (which acts as a server) in order for suitable information to be output on a display (such as display 114 or 118) of an alert device. In one embodiment, the alert information received from the wearable device 100 may comprise an identifier (e.g. a MAC address) of the wearable device 100. The information output for display on each of one or more alert devices is then retrieved from the storage medium 126 of the alert device 110A by the controller 103 and used to generate the information output for display. In the case that the alert information is forwarded by the alert device 110A to one or more other alert devices (such as alert device 110B), the information retrieved from the storage medium 126 may be included in the forwarded alert information. The relevant information associated with a particular wearable device 100 (e.g. associated with that wearable device’s MAC address) may be stored in the storage medium 126 in advance (e.g. during an initial registration process of the wearable device 100) and retrieved from the storage medium 126 using a lookup table stored in the storage medium 126 (the lookup table relating the MAC address of each wearable device 100 with one or more pieces of information associated with that wearable device 100).

One piece of information which may be included in the alert information (and is included in the case of Figure 2A) is the location of the patient at the time that the predetermined physiological event (in this example, a cardiac arrest), is detected. Such information is very useful, particularly in the case that the physiological event is sufficiently serious for help to be sent to the patient immediately at their current location. The location of the patient is determined by the location circuitry 104 comprised within the wearable device 100. This location circuitry may comprise one or more types of Global Navigation Satellite System (GNSS) circuitry configured to determine the position of the wearable device 100 (and therefore of a patient wearing the wearable device) using satellite signals. An example of such a system is the Global Positioning System (GPS), in which case, the location circuitry 104 is a GPS receiver. The location circuitry 104, instead of or in addition to using a GNSS location method, may be able to determine the location of the wearable device 100 via non-satellite methods, e.g. based on the position of one or more cellular base stations (such technology is known in the art and will therefore not be discussed in detail here).

It will be appreciated that, alternatively, an implanted medical device 106 itself may comprise location circuitry 104 instead of the wearable device 100 comprising the location circuitry 104. In this case, location information generated by the location circuitry 104 is transmitted to the wearable device 100 from the implanted medical device 106 (e.g. as part of information transmitted from the transmitter 108 of the medical device 106 to the receiver 101 of the wearable device via a wireless (e.g. radio) signal). However, by having the location circuitry 104 located in the wearable device 100, the benefits of the alert information comprising real-time location information of the patient are realised without the need for the implanted medical device 106 to comprise the location circuitry 104. In particular, such an arrangement allows existing medical devices 106 such as ICDs which do not include location circuitry 104 to be used with the wearable device 100 whilst still allowing the location of the patient to be included in alert information transmitted by the wearable device 100 in the case that a predetermined physiological event such as a cardiac arrest (in the case of an ICD) occurs.

According to an embodiment, Figure 6 shows a sequence of events which occur when the implanted medical device 106 is an ICD, the wearable device 100 is configured to detect an electrical signal transmitted by the ICD as a result of an electric shock applied to a patient and in which a cardiac arrest occurs. The top portion of Figure 6 shows an electric cardiogram 500 of the patient. The electric cardiogram is indicative of electrical activity of the patient’s heart over time, as detected by the detector 107 of the implanted ICD. Initially, as indicated by 500A, the patient’s heart rhythm is normal. As demonstrated by the next portion 501 of Figure 6, this results in the wearable device 100 (which, in this embodiment, has a display 502 such as a liquid crystal display (LCD) or the like) exhibiting a function in which alert information is not transmitted to an alert device. In this case, as indicated by 501A, the display 502 of the wearable device 100 shows a clock face so as to enable the patient 300 to see the current time, the wearable device 100 therefore performing the function of an ordinary wristwatch. It will be appreciated that the wearable device 100 may further comprise other functions in addition to the core function of detected a signal output by the medical device 106 (such as various calendar, reminder, messaging functions or the like).

At a subsequent time, however, the patient’s heart rhythm changes (see point 500B). This is detected by the detector 107 as a dangerous cardiac arrhythmia indicative of a cardiac arrest. In response to his, as indicated by 500C, an electric shock is delivered to the patient by the ICD device. In this case, a 35 joule shock is delivered. The electrode which delivers the shock acts as the transmitter 108 of the ICD and an electrical signal resulting from the application of the electric shock is detected by the wearable device 100 (in particular, by the receiver 101 of the wearable device 100). The wearable device 100 therefore indicates on its display 502 that the electrical signal indicative of the applied shock has been detected. This is indicated at step 501B (in which the information displayed on the display 502 of the wearable device 100 is changed to indicate the detection of the signal transmitter by the ICD). Looking back to the top portion 500 of Figure 6, it can be seen that the shock applied to the patient has corrected the dangerous arrhythmia and that the patient’s heart rhythm has therefore returned to normal. However, because of the application of the shock, the recommendation is that the patient is checked over by a doctor or healthcare professional. Thus, in response to the detection by the receiver 101 of the electric signal, at step 501C, alert information is transmitted by the transmitter 102 of the wearable device 100. In this case, the alert information 503 comprises information indicative of the cardiac arrest occurring together with GPS position information determined by the location circuitry 104 of the wearable device 100. The alert information is received by an alert device 110 (in the form of a smartphone) of a person previously chosen by the patient to receive alerts in the event of a cardiac arrest occurring. For example, this person may be a relative, friend or carer of the patient. This is shown in portion 504 of Figure 6. In addition to the alert device 110 receiving the alert information, alert information is also transmitted to a customer support service (in particular, to an alert device at a premises of the support service) which alerts an employee of the support service (e.g. a healthcare professional) of the cardiac arrest. This alert occurs at step 506. The employee may then call the patient at step 507 and/or call the relative, friend or carer of the patient at step 508 to find out more information about the incident and to provide advice on what next steps need to be taken. It is noted that, in Figure 6, the term “LOIS” is an acronym for “Loved Ones Information Service” (highlighting the fact that embodiments of the present technique allow a loved one (such as a partner or family member) of a patient 300 to be notified quickly of medical emergencies detectable by a medical device implanted in the patient 300.

Figure 7 schematically shows a method of operating the wearable device 100. The method starts at step 700. At step 701, the receiver 101 is controlled to receive a signal from the medical device 106 implanted within the body of a wearer of the wearable device, the signal being transmitted by the implanted medical device in response to detection by the implanted medical device of a predetermined physiological event. At step 702, the transmitter 102 is controlled to transmit, in response to the receiver 101 receiving the signal from the implanted medical device 106, alert information to one or more alert devices for alerting a person other than the wearer of the wearable device of the occurrence of the predetermined physiological event. The method then ends at step 703.

Figure 8 schematically shows a method of operating the medical device 106, the medical device being implantable in a body of a user. The method starts at step 800. At step 801, the detector 107 is controlled to detect, when the medical device is implanted in a body of a user, a predetermined physiological event. At step 802, the transmitter 108 is controlled to transmit, in response to the detector 107 detecting the predetermined physiological event, a wireless signal to the wearable device 100 worn by the user. The wearable device 100 is configured to transmit, in response to receiving the wireless signal from the implanted medical device, alert information to one or more alert devices for alerting a person other than the wearer of the wearable device of the occurrence of the predetermined physiological event. The process then ends at step 803.

Figure 9 schematically shows a method of operating an alert device (such as alert device 110A). The method starts at step 900. At step 901, a receiver (such as receiver 111) is controlled to receive, from the wearable device 100 worn by a user, alert information, the alert information being transmitted by the wearable device worn by the user in response to the wearable device receiving a signal transmitted by the medical device 106 implanted within the body of the user in response to the implanted medical device detecting a predetermined physiological event. At step 902, information output circuitry (such as information output circuitry 112) is controlled, in response to the receiver 111 receiving the alert information, to output information indicative of the occurrence of the predetermined physiological event to a person other than the user wearing the wearable device.

Numerous modifications and variations of the present disclosure are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the disclosure may be practiced otherwise than as specifically described herein.

In so far as embodiments of the disclosure have been described as being implemented, at least in part, by software-controlled data processing apparatus, it will be appreciated that a nontransitory machine-readable medium carrying such software, such as an optical disk, a magnetic disk, semiconductor memory or the like, is also considered to represent an embodiment of the present disclosure.

It will be appreciated that the above description for clarity has described embodiments with reference to different functional units, circuitry and/or processors. However, it will be apparent that any suitable distribution of functionality between different functional units, circuitry and/or processors may be used without detracting from the embodiments.

Described embodiments may be implemented in any suitable form including hardware, software, firmware or any combination of these. Described embodiments may optionally be implemented at least partly as computer software running on one or more data processors and/or digital signal processors. The elements and components of any embodiment may be physically, functionally and logically implemented in any suitable way. Indeed the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units. As such, the disclosed embodiments may be implemented in a single unit or may be physically and functionally distributed between different units, circuitry and/or processors.

Although the present disclosure has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Additionally, although a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognize that various features of the described embodiments may be combined in any manner suitable to implement the technique.

Claims

1. A wearable device comprising:

receiver circuitry configured to receive a signal from a medical device implanted within the body of a wearer of the wearable device, the signal being transmitted by the implanted medical device in response to detection by the implanted medical device of a predetermined physiological event; and transmitter circuitry configured to transmit, in response to the receiver circuitry receiving the signal from the implanted medical device, alert information to one or more alert devices for alerting a person other than the wearer of the wearable device of the occurrence of the predetermined physiological event.

2. A wearable device according to claiml, wherein the signal received from the implanted medical device is a wireless signal.

3. A wearable device according to claim 1, wherein the signal received from the implanted medical device is an electric signal transmitted from the implanted medical device to the wearable device via organic tissue of the wearer of the wearable device.

4. A wearable device according to claim 3, wherein:

the implanted medical device is an Implantable Cardioverter Defibrillator (ICD);

the predetermined physiological event is a cardiac arrhythmia indicative of a potential cardiac arrest; and the source of the electric signal received by the receiver circuitry is an electric shock generated by the ICD for alleviating the cardiac arrhythmia indicative of a potential cardiac arrest.

5. A wearable device according to any preceding claim, wherein the transmitter circuitry is configured to transmit the alert information to the one or more alert devices via a communications network.

6. A wearable device according to claim 5, wherein the communications network comprises a mobile telecommunications network.

7. A wearable device according to claim 5 or 6, wherein the communications network comprises a local area network (LAN).

8. A wearable device according to any preceding claim, wherein the alert information comprises data associated with the detected predetermined physiological event generated based the signal received from the implanted medical device.

9. A wearable device according to claim 8, wherein the data associated with the detected predetermined physiological event comprised within the alert information comprises information indicative of a location of the wearer of the wearable device.

10. A wearable device according to claim 9, comprising location circuitry configured to determine the location of the wearer.

11. A wearable device according to any preceding claim, wherein one of the one or more alert devices is for alerting a healthcare professional of the occurrence of the predetermined physiological event.

12. A wearable device according to any preceding claim, wherein one of the one or more alert devices is for alerting a person previously chosen by the wearer of the wearable device of the occurrence of the predetermined physiological event.

13. A medical device implantable in a body of a user, the medical device comprising:

detection circuitry configured to detect, when the medical device is implanted in a body of a user, a predetermined physiological event; and transmitter circuitry configured to transmit, in response to the detection circuitry detecting the predetermined physiological event, a wireless signal to a wearable device worn by the user, the wearable device being configured to transmit, in response to receiving the wireless signal from the implanted medical device, alert information to one or more alert devices for alerting a person other than the wearer of the wearable device of the occurrence of the predetermined physiological event.

14. An alert device comprising:

receiver circuitry configured to receive, from a wearable device worn by a user, alert information, the alert information being transmitted by the wearable device worn by the user in response to the wearable device receiving a signal transmitted by a medical device implanted within the body of the user in response to the implanted medical device detecting a predetermined physiological event; and information output circuitry configured, in response to the receiver circuitry receiving the alert information, to output information indicative of the occurrence of the predetermined physiological event to a person other than the user wearing the wearable device.

15. An alert device according to claim 14, wherein the person other than the user wearing the wearable device is a healthcare professional.

16. An alert device according to claim 14, wherein the person other than the user wearing the wearable device is a person previously chosen by the wearer of the wearable device.

17. A method of operating a wearable device comprising receiver circuitry and transmitter circuitry, the method comprising:

controlling the receiver circuitry to receive a signal from a medical device implanted within the body of a wearer of the wearable device, the signal being transmitted by the implanted medical device in response to detection by the implanted medical device of a predetermined physiological event; and controlling the transmitter circuitry to transmit, in response to the receiver circuitry receiving the signal from the implanted medical device, alert information to one or more alert devices for alerting a person other than the wearer of the wearable device of the occurrence of the predetermined physiological event.

18. A method of operating a medical device implantable in a body of a user, the medical device comprising detection circuitry and transmitter circuitry, wherein the method comprises:

controlling the detection circuitry to detect, when the medical device is implanted in a body of a user, a predetermined physiological event; and controlling the transmitter circuitry to transmit, in response to the detection circuitry detecting the predetermined physiological event, a wireless signal to a wearable device worn by the user, the wearable device being configured to transmit, in response to receiving the wireless signal from the implanted medical device, alert information to one or more alert devices for alerting a person other than the wearer of the wearable device of the occurrence of the predetermined physiological event.

19. A method of operating an alert device , the alert device comprising receiver circuitry and information output circuitry, wherein the method comprises:

controlling the receiver circuitry to receive, from a wearable device worn by a user, alert information, the alert information being transmitted by the wearable device worn by the user in response to the wearable device receiving a signal transmitted by a medical device implanted within the body of the user in response to the implanted medical device detecting a predetermined physiological event; and controlling the information output circuitry, in response to the receiver circuitry receiving the alert information, to output information indicative of the occurrence of the predetermined physiological event to a person other than the user wearing the wearable device.

20. A program for controlling a computer to perform a method according to any one of claims 17 to 19.

21. A storage medium storing a program according to claim 20.

Amendments to the claims have been filed as follows :