Patent Application
20070250138
The invention will now be described in detail in relation to preferred embodiments and implementation thereof which is exemplary in nature and descriptively specific as disclosed. It must be understood that no limitation of the scope of the invention is thereby intended. The invention encompasses such alterations and further modifications in the illustrated method and apparatus, and such further applications of the principles of the invention illustrated herein, as would normally occur to persons skilled in the art to which the invention relates.
The present invention is based upon the principle that cooling or warming the scalp over certain regions of brain both triggers and maintains the physiological processes impacted by neurological disorders. For example, but not by way of limitation, cooling the prefrontal cortex of the brain can help treat the physiological processes that lead to sleep onset and sleep maintenance and thereby assist in the treatment of sleep disorders. In this example, the mechanism by which this occurs may include any or some combination of the following: 1) a reduction in metabolism in the prefrontal cortex that is necessary for the onset and maintenance of sleep; 2) a triggering of the normative drop in core body temperature that occurs as part of the sleep onset process; 3) a reduction in cognitive arousal that is mediated by increased metabolic activity in the prefrontal cortex in insomnia patients.
The method and device of this embodiment of the present invention more generally involves the application of a noninvasive, regionalized thermic stimulus to a patient's head in order to impact and adjust brain metabolism and thereby obtain the clinical benefits of treating neurological disorders.
Again by way of example, the brain cooling method and device of the present invention obtains these benefits by decreasing hypermetabolism associated with such disorders. The brain cooling method and device of the present invention also reduces the cognitive hyperarousal that prevents the natural entry into sleep in insomnia patients and facilitates the changes in thermoregulation associated with sleep onset. In the case of a hyper-thermic stimulus of the present invention, or non-invasive, regionalized brain warming, therapeutic benefits can be achieved where an increase to the metabolism to a localized area of a patient's brain is desired.
In general, the regional brain thermal stimuli method and device of the present invention cools or warms the scalp or skull of a patient and, in turn, cools or warms the temperature of the brain inside the skull of the patient where the invention is applied. As used in this application, the terms “regional” and “regionalized” refer to such an application of the present invention in a specific or localized area or region of the brain; and “thermal stimuli” and related variations of this phrase refer to hypothermal stimuli or cooling as well as hyper-thermal stimuli or warming. The application of a noninvasive, regionalized thermal stimulus to the scalp is associated with adjustments, i.e., reductions or increases in metabolism in the underlying cortex and such an intervention facilitates treatment of patients with neurological disorders. Again by way of example in an embodiment of the invention applying brain cooling, the invention can also facilitate sleep onset and improve sleep quality.
To help illustrate and describe the present invention, the following discussion focuses, first, on the general method of the invention and then on the general device of the present invention as they relate to brain cooling. A particular embodiment of the present invention having application to the treatment of sleep disorders such as insomnia through brain cooling is then described as one example of, but not a limitation on, the invention. Other embodiments may employ brain cooling for other regions of the brain and associated disorders, as well as brain warming for purposes of brain disorder treatment.
The method of the present invention involving a hypothermal stimuli or brain cooling generally involves the application of noninvasive, regionalized cooling to the brain, during an optimal time and at optimal temperatures, to change brain metabolism/activity in a regionally specific manner to treat brain disorders and, in particular, that is specific to each disorder based on known regional abnormalities in brain metabolism/activity found in the scientific literature for the disorder.
More specifically, the method of regional brain cooling of the present invention comprises the steps of noninvasive, regional cooling of the brain at a localized area of the brain where thermal stimulation will provide therapeutic benefits, application of such cooling at an optimal time based upon the disorder being treated and application of an optimal temperature reduction based upon the characteristics of the same disorder. The noninvasive, regional brain cooling step generally involves the use of the device of the present invention. The method of the present invention can further include the step of monitoring patient response to the cooling process and make corresponding adjustments to the timing and/or temperature of the cooling process.
Optimal timing for application of the regional thermal stimulation method of the present invention depends upon the nature of the neurological or brain disorder being treated. Optimal cooling temperatures similarly depend upon the nature of the subject disorder. The cooling method of the present invention can alternatively produce cooling cycles during use, that is, cooling can be on for a set period or periods of time and off for a set period or periods of time. The cycles are dependent on a particular patient's response to the treatments. Different cooling temperatures can also be used during treatment periods.
The thermal stimulation method of the present invention can also include the step of patient monitoring. Patients can be monitored in several ways. For example, during the application of the regionalized cooling method in a sleep laboratory setting, patients can be monitored for the presence or absence of sleep, as well as the depth of sleep as assessed by the presence of slow waves using polysomnography. Temperature probes on the surface of the scalp underneath the cooling device can monitor the temperature of the cooling and, in an alternative embodiment can provide programmed feedback to the regional brain cooling device to allow for desired temperature adjustments. This monitoring process step can also take place by any means, including electronic, known to those skilled in the art that help accomplish the functional goal of noninvasive, regionalized brain cooling for the purpose of treating neurological disorders.
The method of the present invention is used to treat disorders of the brain in which regional changes in brain activity may be beneficial. There exists a broad range of brain disorders in the fields of neurology and psychiatry, including sleep disorders associated with these neurological and psychiatric disorders, in which a change in brain activity, through regionalized brain cooling is beneficial.
For certain of these disorders, the indication is the treatment of the sleep disturbances associated with the disorders, which in turn, benefit the general condition itself. For example, in depressed patients, metabolism in the prefrontal cortex does not decline from waking to NREM sleep to the same degree as it does in healthy subjects. This abnormality in changes in regional brain metabolism across the wake/sleep period is important in either the causes of depression or in the maintenance of depression and especially in the sleep complaints often reported by these patients. Similar changes in the prefrontal cortex across the wake/sleep periods have been noted in healthy aging, and are presumed to be present in other neuropsychiatric disorders in which there is a disturbance in the ability to either fall asleep or to stay asleep during the night. Examples of such disorders include post-traumatic stress disorders, anxiety disorders and sleep disorders associated with aging and the dementias. The present invention also applies to treat these disorders by allowing for optimal regionalized placement, optimal cooling temperatures and optimal timing of cooling treatments that are appropriate for the disorder.
For other patients, the present invention can be applied during waking hours in connection with other neurological disorders. As an example, a neurological disorder characterized by parietal lobe metabolic abnormalities may be effectively treated by application of localized parietal scalp cooling for one hour three times per day during waking hours.
Referring to
Referring to device to
For embodiments of the invention as depicted in
Various attachment means known to those skilled in the art can be used to attach the regional brain cooling device of the embodiments depicted in
The device of the present invention is adjustable so that it can fit a plurality of different head sizes and in turn fit a plurality of patients. The apparatus accomplishes this adjustment means by any way known in the art that serves the functional goal of localized temperature control, including but not limited to snaps, Velcro or elastic.
The device of the present invention is generally placed over those regions or localized areas of the brain where cooling is desired. For example, but not by way of limitation, in an embodiment of the invention where insomnia is addressed as a neurological disorder, the device is placed on the frontal area or more particularly placed over the forehead and temporal region of the patient's skull, as shown in
In connection with the embodiment of the invention having application to treatment of insomnia and sleep disorders, modifications to the regional brain cooling device can be made to allow it to be used in conjunction with headgear associated with the administration of positive airway pressure treatment for sleep apnea or other sleep apnea devices, such as devices that produce a “puff” instead of constant positive pressure. These devices commonly consist of a soft plastic hollow mask that fits over the nose and/or nose and mouth of the patient. The devices also can have associated head straps attaching the masks firmly to the face of a patient and keeping the tubing that channels the air from the pressurizing machine to the mask in place.
There are a variety of configurations of headgear for holding the sleep apnea devices and/or masks in place over the oral or nasal airway passages. By way of example, but not limitation, combined sleep apnea devices and cooling headgear may consist of a variety of configurations to allow for both the holding of the mask in place as well as for the cooling of the frontal and temporal regions of the brain. In these cases, the cooling head device is configured on the inside of the headgear that holds the mask in place so that the straps for the mask keep in place both the face mask as well as the cooling device on the forehead. The straps are configured around the cooling device in such a way as to hold both the airway mask and the cooling device in place yet do not impede the circulation of fluids or gases, if any, through the cooling device.
The noninvasive, regional brain cooling of the present invention can occur using any cooling method that also serves the functional goal of localized temperature control for the treatment of neurological disorders. By way of example, but not limitation, one method of cooling is by pumping or flowing cooling fluids through the brain cooling device or optionally through a plurality of channels within the device. The terms “fluid” or “fluids” as used herein can describe a fluid, slurry or a gas or some combination thereof. By way of further example, but not limitation, where circulated cooling fluids are used, such cooling fluids can circulated by a pump or other means through a circulation system that includes a cooling chamber, insulated tubes (about 5-20 mm in diameter) that run from the chamber to the device, tube connectors on the device that allow for the connection of the tubes to the channels of the device and channels in the device (about 1-20 mm in diameter) that overlie the inner layer that is in contact with the scalp. Temperature probes on the surface of the scalp can provide feedback to the cooling chamber to adjust the temperature of the cooling fluids up or down to achieve the desired cooling temperature on the scalp. The cooling chamber may be any one of several commercially available units that allow for the cooling of fluids and pumps that circulate these fluids from the chamber to the device. The cooling chamber and pumps can be programmable to provide a range of temperatures and durations of cooling to achieve maximal cooling. The pumps also can be programmable to provide a variation to pressures of the fluids to achieve maximal cooling.
For the purposes of sleeping with the device in place, the walls of the channels for circulating the fluid are both flexible to allow for increased comfort and deformability to the contours of individual heads, yet have sufficient internal rigidity to resist compression of the channels due to the weight of a head on a pillow. The internal walls of the chamber also direct the flow of fluids evenly across the entire device to provide an even distribution of cooling over the entire surface of the device.
Another method of cooling includes passing a cooled fluid directly over the skull or scalp of a patient. Yet another method of cooling is a chemical reaction that occurs instantly between two chemicals when mixed together produces cooling. A cold pack provides an example of such a chemical reaction, but other similar reactive cooling methods can also be employed. Still another method of cooling is thermoelectric cooling based on the Peltier Effect, by which DC current is applied across two dissimilar materials causing a temperature differential.
In one embodiment of the present invention, the device consists of device having three layers. The interior layer of the apparatus fits directly on the scalp surface and is made of a material that allows for maximal comfort and that has good thermal conductive properties. The material is preferably a synthetic or the like, although other materials can be used. The middle layer optionally comprises a series of channels for circulating a fluid. The fluids may consist of a variety of elements typically used for cooling, for example, air, water, coolant or similar fluid. This middle layer can also consist of electrical refrigerant elements that produce cooling. The outer or inner layer can also house the fluid and/or channels. Further, the channels can be eliminated from the middle layer and the fluid directly flowed or pumped into and through the middle layer.
In this embodiment, the middle coolant layer is preferably designed to have varying temperatures that may differ for each individual patient according to their neurological disorder and clinical response. For example, but not as a limitation, the preferred cooling temperature in an embodiment of the invention having application to insomnia and sleep disorders ranges from about freezing (0 degrees Celsius) to just about above body temperature (about 37 degrees Celsius). Also in such an embodiment, the preferred temperature range can vary during the time of application of the device prior to sleep and throughout the sleeping period. Different behavioral states, such as waking, NREM and REM sleep, can require different temperatures in order to have maximal benefit, yet maintaining adverse events low and comfort high.
By way of example, but not limitation, an embodiment of the cooling method and device of the present invention is now described as applied to the treatment of insomnia or sleep disorders. In this embodiment, regionalized cooling preferably occurs on the frontal area of a patient's skull. Application of a cooling stimulus to the surface of the scalp decreases temperature and subsequent metabolism in the prefrontal cortex. In this content, this cooling stimulus also decreases cognitive arousal, facilitates core body temperature declines associated with sleep onset, increases depth and quality of sleep, reduces sleep onset and provides neuroprotection during sleep in sleeping disorder patients. All of these effects are associated with an improved quality of sleep and a sense of more restorative sleep.
In the embodiments of the method of this invention applicable to treatment of sleep disorders, the periods of application of cooling that are most important to help facilitate and maintain sleep include the pre-sleep period and the sleep period itself. Normal sleep is associated with a pre-sleep decline in core body temperature, a sensation of sleepiness, and a gradual loss of consciousness and a decline in cerebral metabolism overall. Regionally, this decline is notable in the prefrontal cortex. Early sleep is associated with large amounts of slow wave sleep as measured by the amounts of EEG waves that are large in amplitude and low in frequency.
Brain cooling is most appropriate at distinct times across a 24-hour day. Brain and body temperature have distinct 24-hour rhythms. The time of application of regional brain cooling is an important variable in terms of having the desired effect. For example, whole body temperature declines around the time of sleep onset. Augmentation of brain cooling over this time may aid in the transition from wake to sleep. Brain metabolism also declines across the sleep period with some increases in REM sleep.
The brain cooling device can optionally be applied, therefore, depending upon the needs of the patient, (i) only during the pre-sleep period, (ii) only during the sleep period, or (iii) both during the pre-sleep period and during the sleep period in severe cases. Further, the temperature ranges to facilitate sleep onset or to maintain sleep may differ so that programmable features for the application of different temperatures during these two periods are important.
For some patients, cooling may only be necessary in the pre-sleep period. This cooling provides the benefits of reducing core body temperature, reducing metabolic activity in the prefrontal cortex, and reducing cognitive arousal, any of which may shorten sleep latency. Once any of these listed effects occur, sleep may proceed naturally throughout the night and further cooling during sleep may not be necessary. In a preferred embodiment of the method of this invention where pre-sleep cooling is used for the treatment of insomnia or sleep disorders, the patient places the regional brain cooling device on their head within about 10 minutes to 4 hours, and preferably within about 30 minutes to an hour, of their anticipated bedtime and removes it prior to their bedtime. Variations on these time frames can also be used, though, and are within the scope of this embodiment of the invention.
For other patients, cooling may be used both prior to sleep onset and throughout the sleeping period. Such patients may have difficulty maintaining sleep because of their inability to have declines in whole brain metabolism, or in frontal metabolism and/or their inability to generate the slow wave sleep or to reduce cognitive activity associated with worries and daily preoccupations. For such patients, an extended period of cooling provides one or more of the following benefits: reduction of core body temperature, reduction of metabolic activity in the prefrontal cortex, reduction of cognitive arousal, shortening of sleep latency, increasing slow wave sleep, decreasing arousals during sleep and increasing total sleep time. In a preferred embodiment of the method of this invention relating to both pre-sleep and sleep brain cooling for treatment of insomnia and sleep disorders, the patient places the device on their head within about 10 minutes to 4 hours, and preferably within about 30 minutes to an hour, of their anticipated bedtime and continues to wear it throughout the night of sleep. While a cooler stimulus may be necessary to facilitate sleep onset (say 0 to 30 degrees Celsius), a slightly warmer temperature may be sufficient to maintain sleep (about 15 to 30 degrees Celsius), but not be too cool as to arouse a patient from sleep. Again, other time frames of application of cooling can also be used and are within the scope of this embodiment of the invention. To increase comfort, the temperature can optionally be modulated in the cooling method of the present invention from body temperature to the desired temperature range over time.
The cooling method of the present invention can also be used solely during sleep without any pre-sleep cooling.
Further, the device may be used in the middle of the night, after a patient awakens from sleep. Patients with insomnia often describe wakening in the middle of the night and having difficulty returning to sleep. At these times, the device may be applied in the middle of the night to facilitate their return to sleep.
A further feature of the device allows patients to have control over the temperature settings of the device. In this application, a control box is placed next to the bed of the patient for easy access while the patient is lying in bed. The control box is connected electrically to the thermostat of the cooling chamber and allows the patient or other users immediate access to control the temperature of the device while they are wearing it. Patients with insomnia often feel a lack of control over their ability to sleep and allowing them to have control over the temperature configuration allows for them to have immediate feedback over the temperature range of the device so they can maximize its comfort and therapeutic efficacy over repeated practice. In this manner, the temperature range is individualized for each subject to maximize comfort, minimize adverse events and maximize efficacy.
In the embodiments of the method of the present invention relating to treatment of insomnia and sleep disorders, the regional brain cooling device can operate to cool the entire time it is in contact with the patient's scalp. However, different cooling cycles and different cooling temperatures can optionally be used during pre-sleep and sleep periods. For example, different cooling temperatures can be used for NREM and for REM sleep-based upon the different degrees of internal body temperature regulation during these periods.
For purposes of treating insomnia and sleep disorders, the preferred cooling temperature for the regionalized cooling method of the present invention is between about 5 degrees Celsius to 37 degrees Celsius and preferably between about 10 degrees Celsius to 30 degrees Celsius. Other cooling temperatures can also be used, though, and are within the scope of this invention. In choosing a particular temperature, several factors should be considered. First, too cool of a temperature or stimulus has an arousing effect and interferes with the patient's sleep. Additionally, too cool of a stimulus (e.g. 0 degrees Celsius) damages scalp tissue and can produce systemic effects related to whole body cooling. Second, too warm of a stimulus is not sufficient to have significant effects on reducing metabolism in the underlying cortex and thus the patient's neurological or neuropsychiatric disorders are not effectively treated. A temperature of between about 10 degrees Celsius to 28 degrees Celsius, as an example, provides a mild, comfortable cooling that does not have any systemic effects, yet still is cool enough to produce metabolic declines in the superficial cortex in close proximity to the stimulus. At this temperature, surface, but not deep, brain tissue shows modest declines in temperature. This temperature of about 10 degrees Celsius and 28 degrees Celsius also is not associated with any adverse effects to the scalp.
The timing of the application of the cooling step in the method of the present invention also has several determinants. First, the cooling stimulus should be applied long enough so that brain cooling occurs at both the scalp and the cortex of the brain underneath the location of application. The range of this application is generally between about 20 and 150 minutes and preferably between about 30 to 60 minutes and may vary outside of these ranges according to the individual patient. For some patients, application may only need to be continued in the time prior to sleep onset in order to facilitate sleep. For other patients, application may be necessary not only prior to sleep but also during sleep.
Where regional brain cooling is applied during sleep, application of the cooling step is desirable during the first NREM sleep cycle, which generally occurs during the first 30 to 70 minutes of sleep. Other patients may require continued cooling throughout the entire period of sleep in order to decrease brain activity and facilitate sleep for this entire period.
This application claims the benefit of U.S. Provisional Application Ser. No. 60/793,680, filed on Apr. 20, 2006.
| Number | Date | Country | |
|---|---|---|---|
| 60793680 | Apr 2006 | US |
