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Title:
A SYSTEM AND METHOD FOR IMPROVING THE RANGE OF MOTION OF A PATIENT
Document Type and Number:
WIPO Patent Application WO/2020/193945
Kind Code:
A1
Abstract:
A system and method for improving the range of motion of a patient A system for improving the range of motion of a patient is disclosed herein. The system comprises at least one sensor for attaching to part of the anatomy of the human or animal body, and a processor for receiving sensor signals from the at least one sensor, wherein the sensor signals comprise information indicating the location and/or orientation of the at least one sensor. The processor is configured to determine a current range of motion of the part of the anatomy based on the sensor signals, and determine a target range of motion based on the current range of motion. The target range of motion is greater than the current range of motion. The processor is configured to output an indication of the target range of motion, and optionally the current range of motion, for displaying to a user.

Inventors:
GOSSLING MARTIN (GB)
Application Number:
PCT/GB2020/050666
Publication Date:
October 01, 2020
Filing Date:
March 16, 2020
Export Citation:
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Assignee:
270 VISION LTD (GB)
International Classes:
A61B5/11; A63B24/00
Domestic Patent References:
WO2012059883A22012-05-10
WO2008129442A12008-10-30
WO2019075185A12019-04-18
Foreign References:
JP2002000584A2002-01-08
US20170251955A12017-09-07
Attorney, Agent or Firm:
WHITE, Andrew (GB)
Download PDF:
Claims:
CLAIMS:

1. A system for improving the range of motion of a patient, the system comprising: at least one sensor for attaching to part of the anatomy of the human or animal body; and

a processor for receiving sensor signals from the at least one sensor, wherein the sensor signals comprise information indicating the location and/or orientation of the at least one sensor, and wherein the processor is configured to:

determine a current range of motion of the part of the anatomy based on the sensor signals;

determine a target range of motion based on the current range of motion, wherein the target range of motion is greater than the current range of motion; and

output an indication of the target range of motion for displaying to a user.

2. The system of claim 1 wherein the processor is configured to determine the target range of motion based on the current range of motion and an objective final range of motion. 3. The system of claim 2 wherein processor is configured to receive patient-specific information relating to the patient, and to determine the objective final range of motion based on the patient-specific information relating to the patient.

4. The system of claim 3 wherein the patient-specific information includes at least one of: age of the patient, sex of the patient, weight of the patient, part of the anatomy to which the sensor is attached, injury history of the patient, treatment duration, and an objective final range of motion.

5. The system of claim 2, 3 or 4, wherein the objective final range of motion is a range of motion an average healthy patient selected from a sample representative of the general population would have for that part of the anatomy.

6. The system of any of claims 2 to 5, wherein the processor is configured to determine the target range of motion based on the current range of motion, the objective final range of motion and a settable effort level.

7. The system of claim 6 wherein the processor is configured to use the settable effort level as a weighting to apply to the current range of motion to determine the target range of motion.

8. The system of any of the previous claims wherein the processor is configured to determine a target range of motion based on the current range of motion by determining an average of a plurality of previous range of motion measurements.

9. The system of any of the previous claims wherein the processor is configured to operate in a test mode and an exercise mode, wherein:

in the test mode the processor is configured to receive sensor signals indicative of a patient moving the part of the anatomy to which the sensor is attached through a range of motion a plurality of times, and to determine the current range of motion used for determining the target range of motion based on the plurality of range of motion measurements, and

in the exercise mode the processor is configured to output an indication of the target range of motion for displaying to the user and to output an indication of instantaneous movements of the sensor for displaying as an overlay on the target range of motion to the user, or vice-versa.

10. The system of claim 9 wherein in the exercise mode the processor is configured not to determine a current range of motion.

1 1 . The system of any of the previous claims wherein the processor is configured to also output an indication of the current range of motion for displaying to a user. 12. The system of any of the previous claims wherein the processor is configured to transform at least one of: (i) the sensor signals received from the sensor and (ii) the indication of the target range of motion, to an image space to show to a user, and/or to provide two dimensional coordinate data defined in a two dimensional coordinate space. 13. The system of any of the previous claims further comprising a display coupled to the processor for displaying the target range of motion of the part of the anatomy to the user.

14. The system of any of the previous claims wherein the processor is configured to: determine that the part of the anatomy is moving through a range of motion by determining, from the sensor signals, when the sensor is moving in a first direction; and determine that a limit of the range of motion has been reached when there is a change in direction of the sensor such that the sensor is moving in second direction opposite to the first direction.

15. The system of claim 14 wherein the processor is configured to:

determine a complete range of motion when at least two limits of the range of motion have been reached, the two limits comprising a first limit travelling in the first direction and a second limit travelling in the second direction; and

use the complete range of motion to determine the current range of motion and the target range of motion. 16. A method of treating a patient to improve the range of motion of a part of their anatomy, the method comprising:

receiving sensor signals from the at least one sensor, wherein the sensor signals comprise information indicating the location and/or orientation of the at least one sensor; determining a current range of motion of the part of the anatomy based on the sensor signals;

determining a target range of motion based on the current range of motion, wherein the target range of motion is greater than the current range of motion; and

outputting an indication of the target range of motion for displaying to a user. 17. The method of claim 16 comprising determining the target range of motion based on the current range of motion and an objective final range of motion.

18. The method of claim 17 comprising receiving patient-specific information relating to the patient, and determining the objective final range of motion based on the patient- specific information relating to the patient.

19. The method of claim 18 wherein the patient-specific information includes at least one of: age of the patient, sex of the patient, weight of the patient, part of the anatomy to which the sensor is attached, injury history of the patient, treatment duration, and an objective final range of motion as set by a clinician.

20. The method of claim 17, 18 or 19, wherein the objective final range of motion is a range of motion an average healthy patient selected from a sample representative of the general population would have for that part of the anatomy.

21 . The method of any of claims 17 to 20 comprising determining the target range of motion based on the current range of motion, the objective final range of motion and a settable effort level.

22. The method of claim 21 comprising using the settable effort level as a weighting to apply to the current range of motion to determine the target range of motion. 23. The method of any of claims 16 to 22 comprising determining the current range of motion by determining an average of a plurality of previous range of motion measurements.

24. The method of any of claims 16 to 23 comprising displaying an interface to a user, the interface operable in a test mode and an exercise mode, wherein:

operating in the test mode comprises receiving sensor signals indicative of a patient moving the part of the anatomy to which the sensor is attached through a range of motion a plurality of times, and determining the current range of motion used for determining the target range of motion based on the plurality of range of motion measurements, and

operating in the exercise mode comprises outputting an indication of the target range of motion for displaying to the user via the interface and outputting an indication of instantaneous movements of the sensor for displaying as an overlay on the target range of motion to the user via the interface, or vice-versa.

25. The method of claim 24 wherein operating in the exercise mode comprises not determining a current range of motion.

26. The method of any of claims 16 to 25 comprising transforming at least one of: (i) the sensor signals received from the sensor and (ii) the indication of the target range of motion, to an image space to show to a user. 27. The method of any of claims 16 to 26 comprising transforming at least one of: (i) the sensor signals received from the sensor and (ii) the indication of the target range of motion, to provide two dimensional coordinate data defined in a two dimensional coordinate space. 28. The method of any of claims 16 to 27 further comprising outputting an indication of the current range of motion for displaying to a user.

29. The method of any of claims 16 to 28 comprising:

determining that the part of the anatomy is moving through a range of motion by determining, from the sensor signals, when the sensor is moving in a first direction; and determining that a limit of the range of motion has been reached when there is a change in direction of the sensor such that the sensor is moving in second direction opposite to the first direction. 30. The method of claim 29 comprising:

determining a complete range of motion when at least two limits of the range of motion have been reached, the two limits comprising a first limit travelling in the first direction and a second limit travelling in the second direction; and

using the complete range of motion to determine the current range of motion and the target range of motion.

31 . A computer readable non-transitory storage medium comprising a program for a computer configured to cause a processor to perform the method of any of claims 16 to

30.

Description:
A system and method for improving the range of motion of a patient

Field of the invention

The present disclosure relates to a system and method for improving the range of motion of a patient.

Background

Understanding the trajectory or range of motion of a part of the anatomy can be very useful, both for sportspersons in training and recovering from injury, but also the elderly or those recovering from surgery including animals such as horses and dogs. Insurance companies and other professional organisations are also looking for‘Evidence Based Outcomes’ where physical data is now required to prove the effectiveness of any treatment or surgery. With the increasing use of health insurance to cover physiotherapy, and the number of sporting injuries rising, better methods need to be found to assess the status of a patient and improve their treatment, especially with the requirement for evidenced-based outcomes. Summary of the invention

Aspects of the invention are as set out in the independent claims and optional features are set out in the dependent claims. Aspects of the invention may be provided in conjunction with each other and features of one aspect may be applied to other aspects. In a first aspect of the disclosure there is provided a system for improving the range of motion of a patient. The system comprises at least one sensor for attaching to part of the anatomy of the human or animal body and a processor for receiving sensor signals from the at least one sensor. The sensor signals comprise position and/or orientation information, for example three dimensional position information, indicating the location and/or orientation of the at least one sensor. The processor is configured to:

determine a current range of motion of the part of the anatomy based on the sensor signals;

determine a target range of motion based on the current range of motion, wherein the target range of motion is greater than the current range of motion; and output an indication of the target range of motion for displaying to a user.

The processor may also be configured to output an indication of instantaneous movements of the sensor and/or the current range of motion for displaying to the user. It will be understood that determining a target range of motion based on the current range of motion may comprise determining a target range of motion based on the limits of the current range of motion. It will be understood that the current range of motion may be different to the instantaneous movements of the sensor. For example, the current range of motion may represent an average of a number of range of motion movements or a range of motion achieved as part of a“test” mode of operation (as described in more detail below), whereas the instantaneous movements of the sensor may represent the real-time movements of the sensor. Advantageously such an aspect may provide a system for improving the range of motion of a patient. It may do this by using the patient’s current range of motion as an input to determine and create a target range of motion. By outputting an indication of the current range of motion and/or the instantaneous movements of the sensor, and the target range of motion, for displaying to a user such as the patient, the patient can see their current movements and work towards trying to reach the target range of motion and thus improve their recovery - in other words a bit like a game. In short, what this means is that by measuring a patient’s current range of motion, this can be used to drive a maximum response from a graphic response system (where the graphic response shows the patient’s range of motion). The patient’s current range of motion is directly linked to their recovery level. By assessing the user with range of motion sensors and range of motion assessment tests (as will be described in more detail below), these results at each stage or phase of their recovery can be used to drive a game.

The processor may be configured to operate in a test mode and an exercise mode. In the test mode the processor is configured to receive sensor signals indicative of a patient moving the part of the anatomy to which the sensor is attached through a range of motion a plurality of times, and to determine the current range of motion used for determining the target range of motion based on an average of the plurality of range of motion measurements and/or the greatest range of motion achieved when operating in the test mode. In the exercise mode the processor is configured to output an indication of the target range of motion for displaying to the user and to output an indication of the instantaneous movements of the sensor and/or the current range of motion for displaying as an overlay on the target range of motion to the user, or vice-versa. In some examples the processor is configured not to determine a current range of motion in the exercise mode. In both the test and exercise modes the processor may be configured to output an indication of the instantaneous movements of the sensor, the current range of motion and/or the target range of motion for displaying to a user.

As the patient recovers, their range of motion will improve. Therefore, in some examples, the processor is configured to determine a new target range of motion. It may do this in response to determining that the current range of motion and/or instantaneous movements of the sensor reaches or exceeds the target range of motion (for example when the patient can comfortably reach the original target range of motion, for example when the patient has performed a selected number of complete range of motion measurements (as described in more detail below with reference to the test mode of operation) that reach or exceed the target range of motion). The new target range of motion is greater than the previous target range of motion so that the patient has to work to reach and meet the new target range of motion, and therefore aid recovery. The result is a safe way for a patient to play the game - they are not overly pushing themselves but in order to continue to meet the target range of motion they have to work/move harder/further than they did before.

The processor may be configured to determine the target range of motion based on the current range of motion and an objective final range of motion. For example, the processor is configured to set the target range of motion as somewhere between the current range of motion and the objective final range of motion. The objective final range of motion may, for example, be the“end goal” range of motion - i.e. the range of motion the patient is aiming to achieve when they are fully recovered. In some examples this may be set by a clinician. In some examples the processor is configured to receive patient-specific information relating to the patient, and to determine the objective final range of motion based on the patient-specific information relating to the patient. The patient-specific information may include at least one of: age of the patient, sex of the patient, weight of the patient, part of the anatomy to which the sensor is attached, injury history of the patient, treatment duration, and an objective final range of motion, for example as set by a clinician. The objective final range of motion may, for example, be a range of motion an average healthy patient selected from a sample representative of the general population would have for that part of the anatomy. The sample may be selected based on the patient- specific information, for example the sample may be selected based on a selected age range.

The processor may be configured to determine the target range of motion by applying a multiplier or weighting to the current range of motion - for example the target range of motion may be a percentage, such as 10%, greater than the current range of motion. In some examples the processor may be configured to determine the target range of motion based on the current range of motion, the objective final range of motion and/or a settable effort level. In some examples the processor is configured to use the settable effort level as a multiplier or weighting to apply to the current range of motion to determine the target range of motion.

The processor may be configured to determine a target range of motion based on the current range of motion by determining the limits of the current range of motion and/or based on the limits of the instantaneous movements of the sensor (for example, the greatest range of motion the user has reached so far by moving the sensor). In some examples, the processor may be configured to determine a target range of motion based on the current range of motion by determining an average of a plurality of previous range of motion measurements (for example by operating in the test mode). In some examples the system further comprises a display coupled to the processor for displaying the current range of motion and the target range of motion of the part of the anatomy to the user. The display may be local or may be remote. The processor may be configured to transform at least one of: (i) the sensor signals received from the sensor, (ii) the indication of the current range of motion and (iii) the indication of the target range of motion, to an image space to show to a user. In some examples the processor is configured to transform at least one of: (i) the sensor signals received from the sensor, (ii) the indication of the current range of motion and (iii) the indication of the target range of motion, to provide two dimensional coordinate data defined in a two dimensional coordinate space. In some examples the processor is configured to: determine that the part of the anatomy is moving through a range of motion by determining, from the sensor signals, when the sensor is moving in a first direction; and determine that a limit of the range of motion has been reached when there is a change in direction of the sensor such that the sensor is moving in second direction opposite to the first direction.

In some examples the processor is configured to: determine a complete range of motion when at least two limits of the range of motion have been reached, the two limits comprising a first limit travelling in the first direction and a second limit travelling in the second direction; and use the complete range of motion to determine the current range of motion and the target range of motion.

In another aspect of the disclosure there is provided a method of treating a patient to improve their range of motion of a part of their anatomy. The method comprises receiving sensor signals from the at least one sensor, wherein the sensor signals comprise information indicating the location and/or orientation of the at least one sensor, determining a current range of motion of the part of the anatomy based on the sensor signals, determining a target range of motion based on the current range of motion, wherein the target range of motion is greater than the current range of motion; and outputting an indication of the target range of motion for displaying to a user. The method may also comprise outputting an indication of the current range of motion and/or instantaneous movements of the sensor for displaying to a user.

The method may further comprise determining the target range of motion based on the current range of motion and an objective final range of motion. In some examples the method further comprises receiving patient-specific information relating to the patient, and determining the objective final range of motion based on the patient-specific information relating to the patient. The patient-specific information may include at least one of: age of the patient, sex of the patient, weight of the patient, part of the anatomy to which the sensor is attached, injury history of the patient, treatment duration, and an objective final range of motion, for example as set by a clinician. In some examples the objective final range of motion is a range of motion an average healthy patient selected from a sample representative of the general population would have for that part of the anatomy.

In some examples the method further comprises determining the target range of motion based on the current range of motion, the objective final range of motion and a settable effort level. The method may comprise using the settable effort level as a weighting to apply to the current range of motion to determine the target range of motion.

The method may further comprise determining a target range of motion based on the limits of the current range of motion. In some examples the method comprises determining a target range of motion by determining an average of a plurality of previous range of motion measurements.

In some examples the method comprises displaying an interface to a user, the interface operable in a test mode and an exercise mode. Operating in the test mode comprises receiving sensor signals indicative of a patient moving the part of the anatomy to which the sensor is attached through a range of motion a plurality of times, and determining the current range of motion used for determining the target range of motion based on an average of the plurality of range of motion measurements and/or based on the greatest range of motion achieved when operating in the test mode. Operating in the exercise mode comprises outputting an indication of the target range of motion for displaying to the user via the interface and outputting an indication of the instantaneous movements of the sensor for displaying as an overlay on the target range of motion to the user via the interface, or vice-versa. In some examples operating in the exercise mode comprises not determining a current range of motion. The method may further comprise transforming at least one of: (i) the sensor signals received from the sensor, (ii) the indication of the current range of motion and (iii) the indication of the target range of motion, to an image space to show to a user.

The method may further comprise transforming at least one of: (i) the sensor signals received from the sensor, (ii) the indication of the current range of motion and (iii) the indication of the target range of motion, to provide two dimensional coordinate data defined in a two dimensional coordinate space.

In some examples the method comprises determining that the part of the anatomy is moving through a range of motion by determining, from the sensor signals, when the sensor is moving in a first direction, and determining that a limit of the range of motion has been reached when there is a change in direction of the sensor such that the sensor is moving in second direction opposite to the first direction. In some examples the method comprises determining a complete range of motion when at least two limits of the range of motion have been reached, the two limits comprising a first limit travelling in the first direction and a second limit travelling in the second direction. The method may comprise using the complete range of motion to determine the current range of motion and the target range of motion.

In another aspect there is provided a computer readable non-transitory storage medium comprising a program for a computer configured to cause a processor to perform the method of the aspect described above.

Drawings

Embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 shows a perspective view of a patient wearing a sensor for use with examples of the disclosure;

Fig. 2 shows a schematic diagram of an example system for improving the range of motion of a patient; Fig. 3 shows an example graphical display that may be presented to a user of the example system of Fig. 2; and

Fig. 4 shows a flow chart of an example method of treatment of the human or animal body, for example using the system shown in Fig. 2.

Specific description

Embodiments of the claims relate to a system for improving the range of motion of a patient, the system comprising at least one sensor for attaching to part of the anatomy of the human or animal body, and a processor for receiving sensor signals from the at least one sensor. Such a sensor is shown in Fig. 1 . Fig. 1 shows a perspective view of a patient wearing a sensor 2. In Fig. 1 the sensor 2 is shown as being attached to the patient’s forearm, although it will be understood that in other examples the sensor 2 may be located on other limbs or parts of the anatomy of the human or animal body, such as the legs or back/spine.

The sensor 2 comprises a processor 203 coupled to a communications interface 201 , which in the example shown is a wireless communications interface. The processor 203 is also coupled to one or more sensor elements 205 and a battery 207. The one or more sensor elements 205 may comprise an accelerometer, a magnetometer and/or gyroscope.

The one or more sensor elements 205 are operable to provide sensor signals to the processor 203. The sensor signals may comprise position information, such as three- dimensional position information, indicating the location of the sensor 2. The sensor signals may additionally or alternatively comprise angle of rotation information, such as pitch, yaw and roll as indicated in Fig. 1. In some examples the processor 203 may be configured to determine position information based on the angle of rotation information and/or changes in the angle of rotation information. The sensor elements 205 may be providing these sensor signals to the processor 203 all the time, or at a selected interval (such as every second, for example every 10 ms). Additionally and/or alternatively the sensor elements 205 may provide the sensor signals only when there is a change in position/orientation detected by the sensor elements 205, for example only when the change in position/orientation exceeds a threshold value (for example a difference of greater than 1 %, greater than 5%, greater than 10%).

The sensor 2 is configured to communicate with a computer 5, as shown in Fig. 2. The computer 5 may be any electronic device, for example a smartphone or a tablet device. Together the sensor 2 and the computer 5 form the system for improving the range of motion of a patient.

The processor 203 of the sensor 2 is configured to receive the sensor signals from the sensor elements 205 and pass them on to the wireless communications interface 201 for sending to the computer 5. The wireless communications interface 201 may be configured to communicate over a short range radio frequency, such as Bluetooth®.

The computer 5 comprises a processor 503 coupled to another communications interface 501 , which in the example shown is a wireless communications interface, and a memory 509. In some examples the computer 5 also has an optional display coupled to the processor 503, and/or a battery.

The wireless communications interface 501 of the computer 5 is configured to receive the sensor signals sent from the sensor 2. In the example shown, the processor 503 is configured to determine a current range of motion of the part of the anatomy based on the received sensor signals. The processor 503 is also configured to determine a target range of motion based on the current range of motion, wherein the target range of motion is greater than the current range of motion. This may comprise determining the limits of the current range of motion, and determining limits of the target range of motion based on the limits of the current range of motion.

The processor 503 is configured to output an indication of the current range of motion and an indication of the target range of motion for displaying to a user. For example, the processor 503 is configured to output the indication to the optional display, or to send the indication to a remote display. For example, the processor 503 may be configured to transform at least one of: (i) the sensor signals received from the sensor 2, (ii) the indication of the current range of motion and (iii) the indication of the target range of motion, to an image space for sending to the display to show to a user, for example as described below with reference to Fig. 3.

The processor 503 may be configured to determine that the part of the anatomy is moving through a range of motion and that a limit of that range of motion has been reached by determining, from the sensor signals, when the sensor 2 is moving in a first direction; and determine that a limit of the range of motion has been reached when there is a change or reversal in direction of the sensor 2 such that the sensor 2 is moving in second direction opposite to the first direction. The processor 503 may be configured to determine a direction of movement based on changes in the angle of rotation of the sensor 2. Additionally or alternatively the patient may press a button that sends a limit of range of motion signal to the computer 5 when a limit of a range of motion has been reached, and the processor 503 receives the limit of range of motion signal and determines a limit of the range of motion based on the receipt of the signal. For example, the button may be on the sensor 2 or on another device in communication with the computer 5 and/or the sensor 2.

In some examples the processor 503 is configured to determine a complete range of motion has occurred when at least two limits of the range of motion have been reached, the two limits comprising a first limit travelling in the first direction and a second limit travelling in the second direction. The processor 503 may be configured to use the complete range of motion to determine the current range of motion and/or the target range of motion. In use, the sensor 2 transmits sensor signals to the computer 5 as the patient moves a part of their anatomy, which in this case may be their arm. As shown in Fig. 4, the computer 5, and specifically the processor 503 of the computer, receives 401 these sensor signals, wherein the sensor signals comprise information indicating the location and/or orientation of the sensor 2.

The processor 503 determines 403 a current range of motion of the part of the anatomy based on the sensor signals. The current range of motion may be the same as the instantaneous movements of the sensor 2, in other words the same as the real-time movements of the user. However, in other examples the current range of motion may represent the user’s current best or maximum range of motion, for example as determined based on an average or rolling average of a plurality of previous range of motion measurements and/or when operating in a test mode, as described in more detail below.

The processor 503 outputs an indication of the current range of motion for displaying to a user. To do this the processor 503 may transform the sensor signals received from the sensor 2 and/or the indication of the current range of motion to an image space for sending to a display to show to a user.

The processor 503 also determines 405 a target range of motion based on the current range of motion. The target range of motion is greater than the current range of motion. The processor 503 also outputs 407 an indication of the target range of motion for displaying to a user. To do this the processor 503 may also transform the indication of the target range of motion to an image space for sending to a display to show to a user.

In the example shown, the processor 503 is configured to operate in a test mode and an exercise mode. The test mode involves the user moving their part of their anatomy (such as their arm) through a selected range of motion, which provides sensor signals that are processed to determine a current range of motion measurement. The exercise mode involves presenting the user with their target range of motion on a display, and displaying alongside this the patient’s current range of motion and/or their instantaneous (i.e. real-time) movements (it will be appreciated that in some examples the patient’s current range of motion may be the same as their instantaneous movements).

In this way, the user can move their part of the anatomy in an to attempt to reach the target range of motion. By outputting an indication of both the instantaneous and/or current range of motion, and the target range of motion, for displaying to a user such as the patient, the patient can see their instantaneous movements and work towards trying to reach the target range of motion and thus improve their recovery - in other words a bit like a game. In short, what this means is that by measuring a patient’s current range of motion, this can be used to drive a maximum response from a graphic response system, as described in more detail below with reference to Fig. 3.

In more detail, operating in the test mode comprises receiving (instantaneous) sensor signals indicative of a patient moving the part of the anatomy to which the sensor 2 is attached through a range of motion a plurality of times (for example, at least five times).

During the test mode the instantaneous movements of the sensor 2 may be displayed as an overlay on an avatar 900, as described in more detail below with reference to Fig. 3. The processor 503 determines that the part of the anatomy has reached a limit of a range of motion by determining, from the sensor signals, when the sensor 2 undergoes a reversal in its direction of movement. Additionally or alternatively the patient may press a button (for example on sensor 2) that sends a limit of range of motion signal to the computer 5 when a limit of a range of motion has been reached. A complete range of motion may comprise two limits or two reversals in direction; one for each extent of the range of motion, although it will be understood that examples may operate using only one limit of the range of motion.

The current range of motion 301 may then determined based on an average of the plurality of (instantaneous) range of motion measurements conducted during the test mode, and/or it may be based on the user’s greatest or maximum range of motion achieved during the test mode.

In some examples, operating in the test mode may comprise guiding the user through a series of test movements or exercises. For example, operating in the test mode comprises the processor 503 outputting an indication of the range of motion measurements that the user should travel through and/or an indication of the number of range of motion measurements needed. In this way, the user can be guided by the computer 5 to perform the correct range of motion exercises for an assessment of the current range of motion.

The processor 503 may operate in the test mode on a periodic basis (for example every week) or it may be configured to operate in a test mode on a schedule based on the number of times the processor 503 has operated in the exercise mode (for example, the processor 503 may be configured to operate in the test mode after the processor 503 has operated in the exercise mode a selected number of times, or for a selected duration). Operating in the exercise mode comprises outputting an indication of the target range of motion for displaying to the user, for example via the user interface presented on the display. The computer 5 receives (instantaneous) sensor signals indicative of a patient moving the part of the anatomy to which the sensor 2 is attached through a range of motion, and outputs an indication of these instantaneous and/or current range of motion values for displaying as an overlay on the target range of motion to the user via the display. In this way, the user can see their instantaneous and/or current range of motion movements and how these compare to the target range of motion. Because the target range of motion is determined by the processor 503 so as not to be too much greater than the current range of motion, the user may then work or stretch themselves to try and reach the target range of motion.

The processor 503 may also be configured to provide tips or hints to the user to help them achieve the target range of motion and improve recovery. For example, the processor 503 may be configured to determine, based on the received sensor signals, whether the user is moving their part of the anatomy correctly, or whether they are moving it incorrectly and have poor technique. If it is determined that the user is not moving their part of the anatomy correctly (for example, if they exhibit movements in a direction outside of a predetermined trajectory of motion with a magnitude greater than a selected threshold), the processor 503 may be configured to display an indication to the user to help correct this, for example by providing an indication to the user of the correct way to move that part of the anatomy. The processor 503 may also be configured to determine the speed at which the patient is moving their part of the anatomy, and provide an indication to speed up or slow down their movement based on a comparison with a target speed of movement, for example held in the memory 509. The target speed of movement may be another patient-specific bit of information input via the user interface, as described in more detail below.

In some examples the processor 503 may also be configured to determine which part of the anatomy the sensor 2 is attached to based on the received sensor signals. For example, based on the range of motion and/or the trajectory of motion, the processor 504 may be configured to determine which part of the anatomy (for example, lower leg vs upper leg vs arm) is being moved and to which the sensor 2 is attached. It may do this by performing a lookup operation and comparing the range and/or trajectory of motion with known ranges and/or trajectories of motion. These may be held, for example, in the memory 509.

It will be understood that in other examples, operating in the exercise mode comprises not determining a current range of motion - for example it may comprise only displaying the instantaneous movements of the sensor 2 as compared to the target range of motion on the display 2.

An example display output from the processor 503 of the computer 5 is shown in Fig. 3. Fig. 3 shows an example display of a user interface that a user of the system may interact with. The processor 503 may be configured to receive inputs from the user interface and make determinations based on the information it receives from the user interface. The processor 503 may also be configured to store such information - the inputs from the user or the determinations based on that information - in the memory 509 for use in later processing steps, such as for example determining a target range of motion.

In the example shown, the display shows a virtual or“avatar” patient 900. As the patient moves their part of the body, which in the example shown is their arm, the sensor 2 sends sensor signals to the computer 5, and the processor 503 of the computer processes these signals and sends signals indicating these instantaneous movements to the display such that the virtual or avatar arm on the display also moves, replicating the patient’s movement in the real world on the display. In this way, the processor 503 may be configured to display the patient’s instantaneous movements in real time on the display.

The display also shows a current range of motion 301 comprising a first limit 305 in a first direction and a second limit 303 in a second direction as an overlay on the avatar patient 900. The display also shows a first target range of motion 309 in the first direction and second target range of motion 307 in the second direction as an overlay on the avatar patient 900, and a first objective final range of motion 313 in the first direction and a second objective final range of motion 31 1 in the second direction as an overlay on the avatar 900. As can be seen in Fig. 3, the target range of motion is greater than the current range of motion 301 , and the objective final range of motion is greater than both the target range of motion and the current range of motion 301 . The display therefore shows a scaled version of the various different ranges of motion - showing the actual angles on a smaller scaled avatar 900 - in a manner that mimics the actual motions performed in the real world.

As shown in Fig. 3, the processor 503 is configured to display, as an overlay, the current range of motion 301 comprising the first limit 305 in the first direction and the second limit 303 in the second direction. It will be understood that displaying the current range of motion 301 may simply comprise displaying the first and/or second limits 305, 303 of the current range of motion. The processor 503 is also configured to display, as an overlay, the target range of motion comprising the first limit 309 and the second limit 307.

Again, it will be understood that displaying the target range of motion may simply comprise displaying the first and/or second limits 309, 307 of the target range of motion. In some examples, the processor 503 is also optionally configured to display, as an overlay, the objective final range of motion comprising the first limit 313 and the second limit 31 1 (and again it will be understood that displaying the objective final range of motion may simply comprise displaying the first and/or second limits of the objective final range of motion), although it will be understood that this is entirely optional because if the difference between the current range of motion and the objective final range of motion is too great, the patient may lose motivation. Displaying any of the current range of motion 301 , the target range of motion and/or the objective final range of motion as an overlay on the avatar 900 may comprise displaying the range of motion in a faint or ghost-like pattern on the display. The instantaneous movements may be shown in a bolder or brighter manner such that the difference between the instantaneous movements and the target range of motion, for example, is noticeable.

The processor 503 may be configured to receive, through the user interface, patient- specific information relating to the patient. The patient-specific information may include at least one of: age of the patient, sex of the patient, weight of the patient, injury history of the patient, and treatment duration, for examples as set by a clinician. For example, when the user turns on or starts the system, the user interface may prompt the user to enter selected patient-specific information. The patient-specific information may be stored by the computer 5 in the memory 509 for reference by the processor 503, for example when determining a target range of motion.

In some examples the processor 503 is configured to determine the target range of motion based on the current range of motion and an objective final range of motion. The objective final range of motion may be set by a clinician and may form part of the patient- specific information. In some examples the processor 503 is configured to determine the objective final range of motion based on the patient-specific information relating to the patient. In some examples the objective final range of motion is a range of motion an average healthy patient selected from a sample representative of the general population would have for that part of the anatomy.

In some examples the user interface may also prompt the user to enter an effort level. The processor 503 may be configured to determine the target range of motion based on the current range of motion, the objective final range of motion and the settable effort level. For example, the processor 503 may be configured to use the settable effort level as a weighting to apply to the current range of motion to determine the target range of motion. For example, the effort levels may comprise easy, medium and hard. On the easy setting, the target range of motion may be 10% greater than the current range of motion. On the medium setting, the target range of motion may be 15% greater than the current range of motion. On the hard setting, the target range of motion may be 20% greater than the current range of motion.

Although the processor 503 of the computer 5 is described as determining a current range of motion of the part of the anatomy based on the received sensor signals, in some examples it will be appreciated that this determination may be performed by the processor 203 of the sensor 2. Additionally or alternatively the processor 203 of the sensor 2 may be configured to determine a target range of motion based on the current range of motion. However, it will be appreciated that performing these determinations on the computer 5 instead of the sensor 2 may conserve the battery life of the sensor 2.

As noted above, in some examples the processor 503 is configured to determine the current range of motion 301 by determining an average of a plurality of range of motion measurements. For example, the current range of motion 301 may be an average of a selected number of previous range of motion measurements, and/or may be a rolling average - for example as determined by the processor 503 operating in a test mode as described above.

However, it will be appreciated that in other examples the current range of motion 301 may be based on instantaneous range of motion 301 measurements. For example, the first limit 305 and the second limit 303 of the current range of motion 301 may be set based on a maximum instantaneous range of motion in that direction. For example, as the user moves their part of their anatomy to which the sensor 2 is attached, the instantaneous movements of the sensor 2 are processed by the processor 503 of the computer 5 and recorded in the memory 509. The processor 503 is configured to compare the sensor signals indicative of the instantaneous range of motion to previously recorded range of motion limits 303, 305, and determine whether to record the instantaneous range of motion measurement as a new current range of motion limit based on the comparison. For example, in the event that an instantaneous movement indicates a range of motion (or a range of motion limit) greater than a previous greatest range of motion measurement (or greatest range of motion limit), the corresponding limit 303 or 305 of the range of motion in that direction is adjusted to be the new limit and stored in the memory 509. In this way, the limits 303, 305 of the current range of motion held in the memory 509 correspond to the maximum range of motion that a user has reached. It will be understood that the processor 503 will use these limits held stored in the memory 509 to determine the target range of motion. As noted above, as the patient recovers, their range of motion will improve. As their range of motion improves, the instantaneous range of motion (or the limits of the instantaneous range of motion) approaches the target range of motion. The processor 503 may compare the instantaneous range of motion to the target range of motion, and determine that the user has reached the target range of motion when the difference between the two is less than a selected threshold. If it is determined that the user has reached the target range of motion, the processor 503 may be configured to determine a new target range of motion (for example based on the new limits of the instantaneous range of motion). In some examples the processor 503 may prompt the user to run in the test mode to determine a new current range of motion and determine a new target range of motion if it is determined that the user has reached the target range of motion.

The new target range of motion will be greater than the previous target range of motion so that the patient has to work to reach and meet the new target range of motion, and therefore aid recovery. In some examples, the determination of the new target range of motion may also be based on the speed at which the user reached a previous target range of motion - for example, if the user reached the target range of motion very quickly, perhaps the previous target range of motion was not challenging enough, and so the new target range of motion may be greater relative to the current range of motion than it previously was.

As noted above, the result is a safe way for a patient to play the game - they are not overly pushing themselves but in order to continue to meet the target range of motion they have to work/move harder/further than they did before.

As noted above, the determination of the target range of motion may also be based on the objective final range of motion. In some examples, as the user begins to reach the objective final range of motion, the difference between the target range of motion and the current range of motion may be decreased, such that the user reaches the objective final range of motion in an asymptotic fashion - i.e. the system allows them to gradually reach the objective final range of motion without a sudden step change in exertion level.

Although the examples described above have been described with reference to only one sensor 2, it will of course be appreciated that the system may operate with a plurality of sensors. For example, a patient may wear a sensor on each limb of a pair - for example on each arm. The processor 503 may be configured to receive signals from both sensors 2 and make a comparison between them. In some examples, the range of motion of one limb may be used as the objective final range of motion of the other - for example if the user only has an injury to one limb but the other limb is functioning normally. In such examples the processor 503 may be configured to perform a comparative and differential analysis between the sensor signals from the plurality of sensors 2.

In some examples the system may require calibration. For example, in examples where the processor 503 may operate in a test mode, each time the processor 503 operates in the test mode the processor 503 may request (by way of providing an indication to a user on a display) that the user performs a calibration operation. This may involve, for example, the user holding their part of the anatomy/the sensor in a particular orientation as indicated by the user interface. For example, the user interface may ask the user to hold the sensor in a particular series of orientations (each optionally for a selected time duration) to perform the calibration operation.

It will be appreciated that the system described in this disclosure may be designed for use with input from a clinical professional, such as with a physiotherapist. As such, the processor 503 may be configured to send information, such as results from the test mode and/or the exercise mode of operation, to a remote device, for example that may be accessible by the clinician. In this way the clinician can keep track of the patient’s recovery. In some examples, the clinician may be able to enter patient specific information for use by the processor 503 in determining the target range of motion via the remote system. Although Fig. 3 shows a display that shows a scaled version of the various different ranges of motion - showing the actual angles on a smaller scaled avatar 900 - in a manner that mimics the actual motions performed in the real world, it will be understood that in other examples the various different ranges of motion may be displayed in a different way. In some examples, an indication of the target range of motion may be shown by way of a graph, bar chart or points system. For example, the target range of motion may be indicated by a progress bar or number of stars or points. The instantaneous and/or current range of motion may be indicated as points along the progress bar or as having a certain number of stars of points (for example the current range of motion may be coloured in a first colour, such as grey or in a faint colour, and the instantaneous range of motion may be in a second colour or in a bright colour, such as yellow or green), with the target range of motion is represented by the end of the progress bar or the maximum number of stars or points achievable. The user is therefore enticed to reach the end of the progress bar or to obtain all of the stars or points available to reach the target range of motion. In examples where the system or processor is configured to determine a new target range of motion, for example in response to a determination that the current and/or instantaneous range of motion reaches or exceeds the target range of motion), the end of the progress bar or the maximum number of stars or points available may be adjusted to represent the new target range of motion. In this way, the user has to work harder to reach the end of the progress bar or the maximum number of stars or points available (i.e. work harder to reach the same point) as the target range of motion increases as the patient begins to recover. In this way the patient is encouraged to continue using the system to improve recovery.

In some examples the processor 503 of the computer 5 is configured to transform at least one of: (i) the sensor signals received from the sensor, (ii) the indication of the current range of motion and (iii) the indication of the target range of motion, to provide two dimensional coordinate data defined in a two dimensional coordinate space.

It will be appreciated from the discussion above that the embodiments shown in the Figures are merely exemplary, and include features which may be generalised, removed or replaced as described herein and as set out in the claims. In the context of the present disclosure other examples and variations of the apparatus and methods described herein will be apparent to a person of skill in the art.