System for cognitive rehabilitation of patients affected by neurological or psychiatric diseases

Abstract

A system for the cognitive enhancement or rehabilitation of a subject comprises a wearable optical instrument by the subject, including a pair of movable prismatic lenses designed to induce a perturbation of the subject's ocular vision; a primary detection device, comprising a sensor adapted to detect the subject's heart rate; and processing means, configured to receive signals indicative of the subject's heart rate from the sensor, process said signals to obtain parameters associated with the heart rate, and impart to the wearable optical instrument a command to modify the orientation and / or transparency of the prismatic lenses based on said parameters associated with the subject's heart rate.

Description

[0001] System for cognitive rehabilitation of patients affected by neurological or psychiatric diseases

[0002] Technical field

[0003] The present invention falls, in general, within the field of rehabilitation equipment in the medical sector; in particular, the invention relates to a system and method for improving the cognitive functions of a patient with neurological or psychiatric diseases, based on the interaction between an optical system interfaced with an electronic platform for generating stimuli and a series of peripheral devices for recording physiological signals.

[0004] Prior art

[0005] The incidence and extent of disabilities attributable to neurological problems are known. In Europe alone, it is estimated that, as of today, 38% of the population suffers from neurological disorders, such as epilepsy, Parkinson's disease, Alzheimer's, Multiple Sclerosis, stroke, and headaches.

[0006] These diseases significantly impact not only the lives of the individuals affected but also those of their families, with considerable economic and socio-assistance repercussions.

[0007] These diseases are of extreme importance. It is sufficient to consider that in Europe, the burden of neurological diseases represents about one-third of overall healthcare expenditure.

[0008] For these reasons and due to their prevalence and incidence in the global population, neurological diseases represent true social illnesses. Numerous international epidemiological studies forecast a dramatic increase in the number of cases of dementia in the next two decades, with the vast majority concentrated in developing countries.

[0009] It is thus necessary to implement rehabilitation practices that help patients retaining or regaining their abilities. The use of devices for cognitive rehabilitation and reconditioning, which exploit a visual distortion induced on the vision of a target stimulus by an individual by means of prismatic lenses supported by appropriate glasses, is known. An example of such a solution, which combines the optical distortion effect with an iterative rehabilitation procedure, is known, for instance, from W02020194180A1.

[0010] Wearable devices for monitoring physiological functions also exist, capable of measuring signals such as heart rate, respiration, movement, and electrodermal activity but cannot directly in a non-invasive manner modulate the subject's cognitive and physiological functions simultaneously.

[0011] Many cognitive variables, such as attention and arousal, are also correlated with the activity of the autonomic nervous system, both sympathetic and parasympathetic, and with the balance between these two systems.

[0012] Heart rate, heart rate variability, pupillometry, psychogalvanic response are measures that allow for detecting the activity of the autonomic nervous system. Although the latter is an autonomous system, its activity is actually correlated with the activation of specific brain areas, which can be impaired in many neurological diseases associated with dysfunctions in these areas.

[0013] In particular, a prevalence of sympathetic autonomic nervous system and a reduction in the parasympathetic have been reported even in the early stages of neurodegenerative diseases, correlated with cognitive functions such as memory. Similar alterations in neurovegetative profiles associated with cognitive dysfunctions have been described in other diseases, such as ADHD and autism.

[0014] Although the scientific literature has highlighted the influence of physiological variables linked to the autonomic nervous system on the effectiveness of non-invasive neuromodulation procedures, no tools or procedures are known that effectively interface neurovegetative signal recording devices, collecting signals from the body’s periphery, with neuromodulation instruments to be implemented in close temporal association with a cognitive training procedure.

[0015] This lack understandably limits or undermines the potential to implement effective neuromodulation procedures.

[0016] Summary of the invention

[0017] An objective of the present invention is to overcome the aforementioned issues.

[0018] To achieve this result, a system for the cognitive rehabilitation of patients affected by neurological or psychiatric diseases provides, according to the present invention, a wearable optical instrument for the subject, including a pair of prismatic lenses whose orientation and / or transparency can be modified, a primary detection device, comprising a sensor adapted to detect the subject's heart rate, and processing means, configured to receive signals indicative of the subject's heart rate from the sensor, process them to obtain parameters associated with the heart rate, and impart to appropriate means (included in the wearable optical instrument) a command adapted to modify the orientation and / or transparency of the prismatic lenses based on these parameters associated with the subject's heart rate.

[0019] The interaction between these components (optical instrument - electronic platform - peripheral devices for recording physiological signals) provides added value compared to the use of each system taken separately, because it provides automatic signals about the subject's cognitive state and automatically guides the use of the optical instrument to optimize cognitive enhancement.

[0020] In this way a device that establishes a bidirectional brain-heart interaction (an interaction that is always impaired in patients with brain lesions), capable of modulating both brain excitability and heart rhythm, is achieved.

[0021] In fact, it is experimentally observed that prismatic adaptation, induced by the lenses’ distortion effect on the subject's vision, modulates the effects of the autonomic nervous system on cardiac activity. Specifically, leftward prismatic deviation increases parasympathetic activity and reduces sympathetic activity, whereas rightward prismatic deviation increases sympathetic activity and reduces parasympathetic activity.

[0022] It is also demonstrated that the low-frequency (LF) component of heart rate variability (Heart Rate Variability, also referred to in scientific literature by the acronym HRV) can be used as an accurate indicator of sympathetic activity, while the high-frequency (HF) component reflects the amplitude of parasympathetic cardiac input fluctuations.

[0023] As it is known, heart rate variability is the oscillation of heart rate over a series of consecutive heart beats during a specific observation period, and its low- and high-frequency components are typically within the ranges of 0.04-0.15 Hz and 0.15-0.40 Hz, respectively.

[0024] According to an embodiment of the invention, the system is configured to adjust the state of the wearable device (glasses with prismatic lenses connected to an information platform) based on the detection of cardiac activity (preferably, heart rate variability, HRV, and / or its low- and high-frequency components, in such a way as to detect the prevalence of the sympathetic or parasympathetic system in the patient). The information platform is preferably configured to compare this detection with cognitive processing data accessible to the platform (indicative, for example, of an objective prismatic conditioning effect) and to provide feedback to the wearable optical device to impose a corresponding deviation to the prismatic lenses.

[0025] For instance, when the ratio between the detected low- and high-frequency components of HRV exceeds 1, possibly combined with cognitive processing data indicating an attention deficit (e.g., when the score achieved by a patient in a specific cognitive test is less than 2.5 standard deviations below the mean score of a control population in the same test), the system may be configured to impose a rotation of the prismatic lenses to the left and a rotation to the right when the ratio between the detected low- and high-frequency components of HRV is less than 1.

[0026] The sampling of heart rate values (and preferably HRV) can continue throughout the period of prismatic adaptation. A stop signal for the prismatic adaptation (with the removal of the glasses) may be provided when the LF / HF ratio equals 1.

[0027] In this way, the brain-heart interaction modulation effect, integrating data indicative of cardiac biological signals with brain data (cognitive performance data), implements a new system that, on one hand, rehabilitates the brain and, on the other, can correct heart rhythm imbalances associated with brain dysfunctions (e.g., brain stroke).

[0028] The aforementioned and other objects and advantages are achieved, according to an aspect of the invention, by a system for the cognitive rehabilitation of patients affected by neurological or psychiatric diseases, having the characteristics defined in claim 1. Preferred embodiments of the invention are defined in the dependent claims.

[0029] Brief description of the drawings

[0030] The functional and structural characteristics of some preferred embodiments of a system and method according to the invention will now be described. Reference is made to the accompanying drawings, wherein:

[0031] - Figure 1 is a schematic perspective view of a wearable optical instrument that is part of the system according to an embodiment of the present invention;

[0032] - Figure 2 is a schematic diagram illustrating a plurality of functional blocks of a system according to an embodiment of the invention; and

[0033] - Figure 3 is a schematic diagram illustrating further plurality of functional blocks of a system according to an embodiment of the invention.

[0034] Detailed description

[0035] Before detailing a plurality of embodiments of the invention, it should be clarified that the invention is not limited in its application to the structural details and the configuration of the components presented in the following description or illustrated in the drawings. The invention can take other embodiments and be implemented or practiced in various ways. It should also be understood that the phraseology and terminology are intended for descriptive purposes and should not be construed as limiting. By way of example, with reference to the figures, a system for the cognitive enhancement or rehabilitation of a subject comprises a wearable optical instrument 10 for said subject, including a pair of prismatic lenses 12 designed to induce a perturbation of the subject's ocular vision.

[0036] The wearable optical instrument 10 comprises means for modifying the orientation and / or transparency of the prismatic lenses.

[0037] Furthermore, there are a primary detection device, comprising a sensor adapted to detect the subject's heart rate and / or the low- and high-frequency components of the subject's heart rate variability, and processing means, configured to receive signals from the sensor indicative of the subject's heart rate (and / or the low- and high-frequency components of the variability thereof), process these signals to obtain parameters associated with the heart rate, and impart to said means of the wearable optical instrument a command to modify the orientation and / or transparency of the prismatic lenses based on said parameters associated with the subject's heart rate.

[0038] According to a preferred embodiment, the wearable optical instrument includes housing seats for the prismatic lenses (formed, for example, in a frame 10a), adapted to rotatably support said prismatic lenses, and actuator means, controlled by the processing means and configured to impart a rotation of the prismatic lenses in their respective housing seats, so as to modify the orientation of said prismatic lenses in response to a signal from the processing means indicative of a command to impart said rotation.

[0039] The prismatic lenses may be formed of laminated glass including a liquid crystal film, and the wearable optical instrument may include an electrical excitation system, controlled by the processing means and configured to switch the properties of the prismatic lenses between a transparent state and an opaque state, in response to a signal from the processing means indicative of a command to excite said liquid crystals.

[0040] According to one embodiment, the detection device includes an accelerometer, said detection device being configured to be worn on the wrist of the subject and to transmit signals to the processing means indicative of wrist movement of the subject detected by the accelerometer. As exemplified in Figure 3, the accelerometer can transmit the detected signals to the electronic processing unit, which may command, for instance, the at least partial or complete darkening of the lenses, to induce a perturbation in the subject's ocular vision.

[0041] The system may also include a display screen for a target visual stimulus, an electronic image generating unit, programmed to generate a predetermined sequence of target visual stimuli visible to the subject, at variable positions on the screen area, and pointing sensors means, configured to detect pointing at the target visual stimulus by the subject. In such a configuration, the prismatic lenses are adapted to intercept and / or deflect a beam of light rays from the target visual stimulus to induce a perturbation of the subject's vision of the target visual stimulus, and the processing means are configured to determine the magnitude of deviation of said pointing position relative to the viewing position of the target visual stimulus, compare said magnitude of deviation with a target deviation parameter, and interact with the optical instrument to modify the state of the prismatic lenses so as to induce said perturbation of the subject's vision of the target visual stimulus as a function of the difference between said magnitude of deviation of the pointing position and said target deviation parameter.

[0042] The sensor of the primary detection device can be configured to detect low- and high- frequency components of the variability within a predetermined time interval of the heart rate, and the processing means can be arranged to interact with the optical instrument in such a way as to modify the state of the prismatic lenses when the ratio between said low- and high-frequency components of the heart rate is different (greater or smaller) than 1, and a difference between the detected magnitude of deviation of the pointing position and the target deviation parameter is less than a predetermined value. For instance, the state of the prismatic lenses can be modified when a score achieved by a patient in a specific cognitive test is below a predetermined threshold (e.g., 2.5 standard deviations below the mean score achieved by a control population in the same test). According to one embodiment of the invention, the state of the prismatic lenses can also be modified by measuring the magnitude of deviation (in degrees of visual angle) between the position of a target visual stimulus (projected, for instance, on a screen) and the position of the same target indicated by the patient wearing the prismatic lenses. For example, when such a deviation (potentially detected multiple times during the test by presenting the subject with a sequence of target stimuli to be pointed at, possibly inducing prismatic conditioning) falls within a predetermined statistical parameter, a command to adjust the prismatic lenses is issued.

[0043] Figure 2 illustrates a schematic functional diagram of a system according to one embodiment of the present invention, which includes a peripheral device for recording physiological signals, an electronic stimulus generation unit, and a neuromodulation instrument (glasses with rotatable prismatic lenses).

[0044] The heart rate values recorded by the detection device are analyzed by a processing unit both in absolute terms and in terms of heart rate variability (HRV), using a time -based analysis metric — for example, in terms of the standard deviation of the interval between a heartbeat and the following one (SDNN), measured in ms, and / or the root mean square of time differences between successive heartbeats (RMSSD).

[0045] Threshold values are defined for each of the aforementioned parameters. Reaching these threshold values will generate a signal that automatically activates the rotation of the prismatic lenses to the right or left. The integration of peripheral signals with neuropsychological results possibly derived from prismatic conditioning, due for example to a dedicated algorithm set on the electronic platform, can also provide feedback on the hemisphere and specific brain area to be neuromodulated, and on the type of digitalized cognitive training to be administered in temporal proximity to the neuromodulation. According to one embodiment, cognitive training is administered also through game-like tests and procedures (also known as serious games), configured as challenges the subject must complete, either individually or sequentially, aiming for a predetermined result (e.g., a certain deviation between a target visual stimulus projected on a screen and the subject's pointing at that stimulus). According to one embodiment, the system further includes a display screen for a target visual stimulus, which may be a projection screen, a computer monitor, a tablet, etc.; an electronic image generation unit, programmed to generate a predetermined sequence of target visual stimuli intended for the subject’s gaze focus, at a variable position on the screen area; pointing sensors means configured to detect the subject’s pointing at the target stimulus (the pointing can be performed by the subject, for instance, using a mouse or a finger); recording means configured to record pointing movements and / or pointing positions by the subject in association with each target stimulus; and processing means for determining the magnitude of deviation, in degrees of visual angle, of said pointing position relative to the viewing position of the target stimulus.

[0046] Conveniently, the electronic image generation unit is programmed to generate said target visual stimuli in a sequence of different positions within the screen area and / or for a variable time or up to the moment when said processing means determine a substantial coincidence of said pointing position relative to the viewing position of the target stimulus.

[0047] The pointing sensors may include a mouse or a touch- sensitive surface of the display screen.

[0048] Storage means may be present, configured to store data indicative of the target deviation parameter.

[0049] According to one aspect of the invention, a method for the cognitive enhancement or rehabilitation of a subject comprises the steps of providing a system according to any of the embodiments described above, and detecting signals indicative of the subject’s heart rate, processing said signals to obtain parameters associated with the heart rate, and imparting to the wearable optical instrument a command to modify the orientation and / or transparency of the prismatic lenses based on said parameters associated with the subject’s heart rate.

[0050] According to a preferred embodiment, the method further includes the steps of detecting the low- and high-frequency components of heart rate variability within a predetermined time interval, and interacting with the optical instrument in such a way as to modify the state of the prismatic lenses when the ratio between said low- and high-frequency components of the heart rate is different from 1, and / or a difference between the detected magnitude of deviation of the pointing position and the target deviation parameter is less than a predetermined value.

[0051] For instance, when the ratio between the detected low- and high-frequency components of HRV exceeds 1, possibly combined with cognitive processing data indicating an attention deficit (for example, when the score achieved by a patient in a specific cognitive test is less than 2.5 standard deviations below the mean score achieved by a control population in the same test), a system and method according to the invention may be configured to impose a rotation of the prismatic lenses to the left, and a rotation to the right when the ratio between the detected low- and high-frequency components of HRV is less than 1.

[0052] Various aspects and embodiments of a system and method for the cognitive rehabilitation of patients affected by neurological or psychiatric diseases according to the invention have been described. It is understood that each embodiment may be combined with any other embodiment. Furthermore, the invention is not limited to the embodiments described but may be varied within the scope defined by the appended claims.

Claims

CLAIMS1. A system for cognitive enhancement or rehabilitation of a subject, comprising:- an optical instrument, wearable by said subject, comprising a pair of prismatic lenses designed to induce a perturbation of the subject's ocular vision, said wearable optical instrument comprising means for changing the orientation and / or transparency of said prismatic lenses;- a primary sensing device, comprising a sensor for detecting the subject's heart rate; and- processing means, arranged to receive from the sensor signals indicative of the subject's heart rate, process said signals to obtain parameters associated with the heart rate, and impart to said means of the wearable optical instrument a command adapted to change the orientation and / or transparency of the prismatic lenses based on said parameters associated with the subject's heart rate.

2. A system according to claim 1, wherein the wearable optical instrument comprises:- prismatic lens housing seats, adapted to rotatably support said prismatic lenses; and- actuator means, controlled by the processing means and suitable for rotating said prismatic lenses in the respective housing seats, in such a way as to change the orientation of said prismatic lenses, in response to a signal from the processing means indicative of a command to rotate said prismatic lenses.

3. A system according to claim 1 or 2, wherein said prismatic lenses are formed of a laminated glass including a liquid crystal film, the wearable optical instrument comprising an electrical excitation system, controlled by the processing means and capable of switching the properties of said prismatic lenses between a transparent state and an opaque state, in response to a signal from the processing means indicative of a command to excite said liquid crystals.

4. A system according to claim 3, comprising a detection device which includes an accelerometer, said detection device being configured to be worn on the wrist of the subject, and to transmit to the processing means signals indicative of a movement of the wrist of thesubject detected by the accelerometer.

5. A system according to any one of the preceding claims, further comprising:- a display screen of a target visual stimulus;- an electronic image generating unit, programmed to generate a predetermined sequence of target visual stimuli visible by the subject, at a variable position on the screen area; and- pointing sensors means, designed to detect pointing at the target visual stimulus by the subject; wherein the prismatic lenses are designed to intercept and / or deflect a beam of light rays from the target visual stimulus in such a way as to induce a perturbation of the subject's vision of the target visual stimulus, and wherein the processing means are arranged to determine the magnitude of deflection of said aiming position relative to the viewing position of the target visual stimulus, comparing said magnitude of deviation with a target parameter of deviation, and interacting with the optical means to modify the state of the prismatic lenses so as to induce said perturbation of the subject's vision of the target visual stimulus as a function of the difference between said magnitude of deviation of the aiming position and said target parameter of deviation6. A system according to any one of the preceding claims, wherein the sensor of the primary detection device is configured to detect low frequency and high frequency components of the variability in a predetermined time interval of the heart rate, and the processing means are arranged to interact with the optical instrument in such a way as to change the state of the prismatic lenses when the ratio of said low frequency and high frequency components of the heart rate is different from 1, and / or a difference between said detected magnitude of deviation of the aiming position and said target deviation parameter is less than a predetermined value.

7. A system according to claim 5 or 6, comprising:- recording means, arranged for recording the pointing movements and / or the pointing position by the subject in association with each target visual stimulus; and- storage means, arranged for storing data indicative of the target deviation parameter.

8. A method for the cognitive enhancement or rehabilitation of a subject, comprising the steps of: (a) providing a system according to any of the preceding claims; and(b) detecting signals indicative of the subject's heart rate, processing said signals to obtain parameters associated with the heart rate, and imparting a command to the wearable optical instrument to change the orientation and / or transparency of the prismatic lenses based on said parameters associated with the subject's heart rate.

9. A method according to claim 8, comprising the steps of detecting low and high frequency components of the variability in a predetermined time interval, and interacting with the optical instrument so as to change the state of the prismatic lenses when the ratio between said low and high frequency components of the heart rate is different from 1, and / or a difference between the detected magnitude of deviation of the pointing position and the target parameter of deviation is less than a predetermined value.

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