Patent Description:
Implantable neurostimulator devices are devices that generate and deliver electrical stimuli to body nerves and tissues for the therapy of various biological disorders, such as pacemakers to treat cardiac arrhythmia, defibrillators to treat cardiac fibrillation, cochlear stimulators to treat deafness, retinal stimulators to treat blindness, muscle stimulators to produce coordinated limb movement, spinal cord stimulators to treat chronic pain, cortical and deep brain stimulators to treat motor and psychological disorders, and other neural stimulators to treat urinary incontinence, sleep apnea, shoulder subluxation, etc. The description that follows will generally focus on the use of the invention within a Spinal Cord Stimulation (SCS) system or a Deep Brain Stimulation (DBS) system, such as disclosed in <CIT> and <CIT>. However, the present invention may find applicability in any medical device system.

An SCS system typically includes an Implantable Pulse Generator (IPG) <NUM> shown in <FIG>. The IPG <NUM> includes a biocompatible device case <NUM> that holds the circuitry and a battery <NUM> for providing power for the IPG to function. The IPG <NUM> is coupled to tissue-stimulating electrodes <NUM> via one or more electrode leads that form an electrode array <NUM>. For example, one or more percutaneous leads <NUM> can be used having ring-shaped or split-ring electrodes <NUM> carried on a flexible body <NUM>. In another example, a paddle lead <NUM> provides electrodes <NUM> positioned on one of its generally flat surfaces. Lead wires <NUM> within the leads are coupled to the electrodes <NUM> and to proximal contacts <NUM> insertable into lead connectors <NUM> fixed in a header <NUM> on the IPG <NUM>, which header can comprise an epoxy for example. Once inserted, the proximal contacts <NUM> connect to header contacts <NUM> within the lead connectors <NUM>, which are in turn coupled by feedthrough pins <NUM> through a case feedthrough <NUM> to stimulation circuitry <NUM> within the case <NUM>, which stimulation circuitry <NUM> is described below.

In the illustrated IPG <NUM>, there are thirty-two electrodes (E1-E32), split between four percutaneous leads <NUM>, or contained on a single paddle lead <NUM>, and thus the header <NUM> may include a 2x2 array of eight-electrode lead connectors <NUM>. However, the type and number of leads, and the number of electrodes, in an IPG is application specific and therefore can vary. The conductive case <NUM> can also comprise an electrode (Ec). In a SCS application, as is useful to alleviate chronic back pain for example, the electrode lead(s) are typically implanted in the spinal column proximate to the dura in a patient's spinal cord, preferably spanning left and right of the patient's spinal column. The proximal contacts <NUM> are tunneled through the patient's tissue to a distant location such as the buttocks where the IPG case <NUM> is implanted, at which point they are coupled to the lead connectors <NUM>.

In a DBS application, as is useful in the treatment of tremor in Parkinson's disease for example, the IPG <NUM> is typically implanted under the patient's clavicle (collarbone), although head-mounted IPGs can also be used. See, e.g., <CIT>. When implanted under the clavicle, percutaneous leads <NUM> are tunneled through the neck and the scalp and the electrodes <NUM> are implanted through holes drilled in the skull and positioned for example in the Subthalamic Nucleus (STN) and the Pedunculopontine Nucleus (PPN) in each brain hemisphere. DBS can also be used for the treatment of neuropsychiatric disorders, such as depression, anxiety, fear, and other neuropsychiatric-related symptoms. For these indications, the electrodes <NUM> may be implanted in different areas of the brain, such Brodmann Area <NUM>, the Subgenual Cingulate, the Medial Forebrain Bundle, the Ventral Capsule or Ventral Striatum, the Nucleus Accumbens, etc. Stimulation may occur in DBS using ring electrodes <NUM>, but split-ring electrodes having directional capabilities can be useful, especially when coupled with multiple current source steering capability.

In other IPG examples designed for implantation directly at a site requiring stimulation, the IPG can be lead-less, having electrodes <NUM> instead appearing on the body of the IPG <NUM> for contacting the patient's tissue. The IPG lead(s) can be integrated with and permanently connected to the IPG <NUM> in other solutions. The goal of SCS therapy is to provide electrical stimulation from the electrodes <NUM> to alleviate a patient's symptoms, such as chronic back pain.

IPG <NUM> can include an antenna 27a allowing it to communicate bi-directionally with a number of external devices discussed subsequently. Antenna 27a as shown comprises a conductive coil within the case <NUM>, although the coil antenna 27a can also appear in the header <NUM>. When antenna 27a is configured as a coil, communication with external devices preferably occurs using near-field magnetic induction. IPG <NUM> may also include a RadioFrequency (RF) antenna 27b. In <FIG>, RF antenna 27b is shown within the header <NUM>, but it may also be within the case <NUM>. RF antenna 27b may comprise a patch, slot, or wire, and may operate as a monopole or dipole. RF antenna 27b preferably communicates using far-field electromagnetic waves, and may operate in accordance with any number of known RF communication standards, such as Bluetooth, Zigbee, WiFi, MICS, and the like.

Stimulation in IPG <NUM> is typically provided by pulses each of which may include a number of phases such as 30a and 30b, as shown in the example of <FIG>. Stimulation parameters typically include amplitude (current I, although a voltage amplitude V can also be used); frequency (f); pulse width (PW) of the pulses or of its individual phases such as 30a and 30b; the electrodes <NUM> selected to provide the stimulation; and the polarity of such selected electrodes, i.e., whether they act as anodes that source current to the tissue or cathodes that sink current from the tissue. These and possibly other stimulation parameters taken together comprise a stimulation program (SP) that the stimulation circuitry <NUM> in the IPG <NUM> can execute to provide therapeutic stimulation to a patient. Various examples of stimulation circuitries can be found in USPs <NUM>,<NUM>,<NUM>, <NUM>,<NUM>,<NUM>, <NUM>,<NUM>,<NUM>, and <CIT> and<CIT>.

In the example of <FIG>, electrode E1 has been selected as an anode (during its first phase 30a), and thus provides pulses which source a positive current of amplitude +I to the tissue. Electrode E2 has been selected as a cathode (again during first phase 30a), and thus provides pulses which sink a corresponding negative current of amplitude -I from the tissue. This is an example of bipolar stimulation, in which only two lead-based electrodes are used to provide stimulation to the tissue (one anode, one cathode). Monopolar stimulation, in which the conductive case acts as an electrode, can also be used. More than one electrode may be selected to act as an anode at a given time, and more than one electrode may be selected to act as a cathode at a given time. Note that at any time the current sourced to the tissue (e.g., +I at E1 during phase 30a) equals the current sunk from the tissue (e.g., -I at E2 during phase 30a) to ensure that the net current injected into the tissue at any time is zero. The stimulation pulses as shown to the left in <FIG> are biphasic, with each pulse comprising a first phase 30a followed thereafter by a second phase 30b of opposite polarity. As is known, biphasic pulses are useful to actively recover any charge that might be stored on capacitive elements in the electrode current paths, such as on the DC-blocking capacitors (not shown) that intervene between the stimulation circuitry's outputs and the electrodes <NUM>. The second pulses phases <NUM> may be followed by passive charge recovery periods 30c, during which the electrode nodes are shorted to a common reference voltage to equilibrate any remaining charge on capacitive elements, as explained for example in <CIT>. Alternatively, and as shown to the right in <FIG>, the pulses may be monophasic, consisting of a single actively-driven pulse phase 30a, followed by a passive charge recovery 30c phase.

<FIG> shows an external trial stimulation environment that may precede implantation of an IPG <NUM> in a patient. During external trial stimulation, stimulation can be tried on a prospective implant patient without going so far as to implant the IPG <NUM>. Instead, one or more trial electrode arrays <NUM>' (e.g., one or more trial percutaneous leads <NUM> or trial paddle leads <NUM>) are implanted in the patient's tissue at a target location <NUM>, such as within the spinal column as explained earlier. The proximal ends of the trial electrode array(s) <NUM>' exit an incision <NUM> in the patient's tissue and are connected to an External Trial Stimulator (ETS) <NUM>. The ETS <NUM> generally mimics operation of the IPG <NUM>, and thus can provide stimulation to the patient's tissue as explained above. See, e.g., <NUM>,<NUM>,<NUM>, disclosing a design for an ETS. The ETS <NUM> is generally worn externally by the patient for a short while (e.g., two weeks), which allows the patient and his clinician to experiment with different stimulation parameters to hopefully find a stimulation program that alleviates the patient's symptoms (e.g., pain, tremor, depression, etc.). If external trial stimulation proves successful, the trial electrode array(s) <NUM>' are explanted, and a full IPG <NUM> and a permanent electrode array <NUM> (e.g., one or more percutaneous <NUM> or paddle <NUM> leads) are implanted as described above; if unsuccessful, the trial electrode array(s) <NUM>' are simply explanted.

Like the IPG <NUM>, the ETS <NUM> can include one or more antennas to enable bidirectional communications with external devices such as those shown in <FIG>. Such antennas can include a near-field magnetic-induction coil antenna 56a, and/or a far-field RF antenna 56b, as described earlier. ETS <NUM> may also include stimulation circuitry <NUM> (<FIG>) able to form stimulation in accordance with a stimulation program, which circuitry may be similar to or comprise the same stimulation circuitry <NUM> (<FIG>) present in the IPG <NUM>. ETS <NUM> may also include a battery (not shown) for operational power.

<FIG> shows various external devices that can wirelessly communicate data with the IPG <NUM> or ETS <NUM>, including a patient, hand-held external controller <NUM>, and a clinician programmer <NUM>. Both of devices <NUM> and <NUM> can be used to wirelessly transmit a stimulation program to the IPG <NUM> or ETS <NUM>-that is, to program their stimulation circuitries <NUM> and <NUM> to produce stimulation with a desired amplitude and timing described earlier. Both devices <NUM> and <NUM> may also be used to adjust one or more stimulation parameters of a stimulation program that the IPG <NUM> is currently executing. Devices <NUM> and <NUM> may also wirelessly receive information from the IPG <NUM> or ETS <NUM>, such as various status information, etc..

External controller <NUM> can be as described in <CIT> for example, and may comprise a controller dedicated to work with the IPG <NUM> or ETS <NUM>. External controller <NUM> may also comprise a general purpose mobile electronics device such as a mobile phone which has been programmed with a Medical Device Application (MDA) allowing it to work as a wireless controller for the IPG <NUM> or ETS, as described in <CIT>. External controller <NUM> includes a user interface, preferably including means for entering commands (e.g., buttons <NUM> or selectable graphical icons) and a display <NUM>. The external controller <NUM>'s user interface enables a patient to adjust stimulation parameters, although it may have limited functionality when compared to the more-powerful clinician programmer <NUM>, described shortly.

The external controller <NUM> can have one or more antennas capable of communicating with the IPG <NUM>. For example, the external controller <NUM> can have a near-field magnetic-induction coil antenna 64a capable of wirelessly communicating with the coil antenna 27a or 56a in the IPG <NUM> or ETS <NUM>. The external controller <NUM> can also have a far-field RF antenna 64b capable of wirelessly communicating with the RF antenna 27b or 56b in the IPG <NUM>.

Clinician programmer <NUM> is described further in <CIT>, and can comprise a computing device <NUM>, such as a desktop, laptop, or notebook computer, a tablet, a mobile smart phone, a Personal Data Assistant (PDA)-type mobile computing device, etc. In <FIG>, computing device <NUM> is shown as a laptop computer that includes typical computer user interface means such as a screen <NUM>, a mouse, a keyboard, speakers, a stylus, a printer, etc., not all of which are shown for convenience. Also shown in <FIG> are accessory devices for the clinician programmer <NUM> that are usually specific to its operation as a stimulation controller, such as a communication "wand" <NUM> coupleable to suitable ports on the computing device <NUM>, such as USB ports <NUM> for example.

The antenna used in the clinician programmer <NUM> to communicate with the IPG <NUM> or ETS <NUM> can depend on the type of antennas included in those devices. If the patient's IPG <NUM> includes a coil antenna 27a, wand <NUM> can likewise include a coil antenna 80a to establish near-filed magnetic-induction communications at small distances. In this instance, the wand <NUM> may be affixed in close proximity to the patient, such as by placing the wand <NUM> in a belt or holster wearable by the patient and proximate to the patient's IPG <NUM> or ETS <NUM>. If the IPG <NUM> or ETS <NUM> includes an RF antenna 27b or 56b, the wand <NUM>, the computing device <NUM>, or both, can likewise include an RF antenna 80b to establish communication at larger distances. The clinician programmer <NUM> can also communicate with other devices and networks, such as the Internet, either wirelessly or via a wired link provided at an Ethernet or network port.

To program stimulation programs or parameters for the IPG <NUM> or ETS <NUM>, the clinician interfaces with a clinician programmer graphical user interface (GUI) <NUM> provided on the display <NUM> of the computing device <NUM>. As one skilled in the art understands, the GUI <NUM> can be rendered by execution of clinician programmer software <NUM> stored in the computing device <NUM>, which software may be stored in the device's non-volatile memory <NUM>. Execution of the clinician programmer software <NUM> in the computing device <NUM> can be facilitated by control circuitry <NUM> such as one or more microprocessors, microcomputers, FPGAs, DSPs, other digital logic structures, etc., which are capable of executing programs in a computing device, and which may comprise their own memories. For example, control circuitry <NUM> can comprise an i5 processor manufactured by Intel Corp, as described at https://www. com/ content/ www/ us/ en/ products/ processors/ core/ i5-processors. Such control circuitry <NUM>, in addition to executing the clinician programmer software <NUM> and rendering the GUI <NUM>, can also enable communications via antennas 80a or 80b to communicate stimulation parameters chosen through the GUI <NUM> to the patient's IPG <NUM>.

The user interface of the external controller <NUM> may provide similar functionality because the external controller <NUM> can include the same hardware and software programming as the clinician programmer. For example, the external controller <NUM> includes control circuitry <NUM> similar to the control circuitry <NUM> in the clinician programmer <NUM>, and may similarly be programmed with external controller software stored in device memory.

<CIT> relates to systems, devices and methods for delivering neural modulation, and discloses a system that may include electrodes on at least one lead configured to be operationally positioned for use in modulating neural tissue. The neural tissue may include at least one of dorsal horn tissue, dorsal root tissue or dorsal column tissue. The system may include an implantable device including a neural modulation device and a controller. The neural modulation device may be configured to use at least some of the electrodes to generate a modulation field to deliver sub-perception modulation to the neural tissue. The sub-perception modulation may have an intensity below a patient-perception threshold. The patient-perception threshold may be a boundary below which a patient does not sense generation of the modulation field. The controller may be configured to control the neural modulation device to generate the modulation field, and automatically adjust the modulation field in response to a patient input.

<CIT> relates to systems, devices, and methods for delivering neural modulation, and discloses a method comprising: accessing, at a computerized system, a patient metric of a subject; using the patient metric as an input to a machine learning algorithm executing on the computerized system, the machine learning algorithm to search a plurality of neuromodulation parameter sets and to identify a candidate neuromodulation parameter set of the plurality of neuromodulation parameter sets, the candidate neuromodulation parameter set designed to produce a non-regular waveform that varies over a time domain and a space domain; and programming a neuromodulator using the candidate neuromodulation parameter set to stimulate the subject.

<CIT> relates to methods for semi-automatically and automatically adjusting, or tuning, treatment parameters in movement disorder therapy devices and systems, and more specifically for remotely adjusting or tuning such devices and systems.

<CIT> relates to electrical stimulation therapy, and, more particularly, deep brain stimulation, and discloses a system comprising an electrical stimulation generator, and a processor configured to determine a patient is in a sleep state and control the electrical stimulation generator to deliver deep brain electrical stimulation to an external portion of a globus pallidus of a brain of the patient based on the determination that the patient is in the sleep state.

<CIT> relates to spinal cord stimulation, and more specifically, to administering spinal cord stimulation (SCS) based on temporal patterns of electrical stimulation with considerations toward efficacy, efficiency and side effects. It discloses a system for delivering electrical pulse stimulation to a subject, which includes: a remote control device configured to at least intermittently transmit temporal pulse pattern programming; and a stimulation device including a control module, at least one electrode in electrical communication with the control module, and an input device in at least intermittent communication with the remote control device to receive the temporal pulse pattern programming, the stimulation device configured to deliver electrical pulse stimulation to a subject via the at least one electrode according to the temporal pulse pattern programming.

The claimed invention is directed towards a medical device system as defined by the appended independent claim <NUM>.

The claimed medical device system comprises: a medical device configured to execute a program to provide neurostimulation therapy to a patient to alleviate a symptom of the patient; at least one non-transitory computer readable medium configured to be executed on an external device configured to adjust the program executed by the medical device; and the external device. The at least one non-transitory computer readable medium is stored in the external device, and the computer readable medium contains instructions for a first algorithm, wherein the first algorithm, when executed on the external device, is configured to: receive at least one qualitative measurement from the patient regarding a status of the patient, receive at least one quantitative measurement taken from the patient, and determine a wellness factor for the patient using the at least one qualitative measurement and the at least one quantitative measurement, wherein the wellness factor is indicative of a severity of the symptom or of the status of the patient.

Further embodiments of the claimed medical device system are described in the appended dependent claims.

A goal of neurostimulation therapy, whether provided by an implanted IPG or externally by an ETS, is the reduction of unwanted symptoms such as pain, tremor, depression, etc. It is therefore useful for many reasons to measure the effectiveness of such therapies.

Typically the effectiveness of SCS therapy is measured qualitatively. Qualitative measurements rely on subjective input from the patient regarding their perception of how SCS therapy is affecting their symptoms. Many qualitative measurements require the patient to rate or rank symptom severity (e.g. pain). For example, the Numerical Rating Scale (NRS) and the Visual Analogue Scale (VAS) allow an SCS patient to rank pain on a scale of <NUM> to <NUM>, with <NUM> denoting no pain and <NUM> denoting a worst pain imaginable. The Patient Global Impression of Change Scale (PGIC) is similar, but measures the success of SCS therapy relative to the patient's symptoms before receiving their implant. For example, a mid-point ranking of <NUM> might indicate that SCS therapy has not improved the patient's pain; a <NUM> might indicate that pain is much improved with therapy; and a <NUM> might indicate that pain is much worse with therapy. The EQ-5D scale can also be used in the SCS therapy context, and addresses wellness concerns beyond pain. The EQ-5D comprises a questionnaire asking a patient to rank various wellness factors that SCS therapy might be impacting, such as patient mobility, ability to provide self-care, pain or discomfort, anxiety or depression, etc. The ranks for each can then be used to compile a single index of wellness. Other qualitative measurements useful for assessing SCS therapeutic effectiveness also exist, and are not limited to patient assessment of pain. SCS patients may also qualitatively rate the effectiveness of SCS therapy by assessment of depression, anxiety, stress, nausea, numbness, dizziness, weakness, fatigue, etc. Qualitative measurement of such other symptoms may occur using the Montgomery-Asberg Depression Rating Scale (MADRS), the Hamilton Depression Rating Scale (HAM-D), Newcastle Depression Scales, and the Clinical Global Impression Scale (CGI). Tremor can also be qualitatively rated by a patient using numerical and other similar scales. Pain, depression, anxiety, stress, obsessive urges, other psychiatric states, nausea, numbness, dizziness, weakness, fatigue can also be useful in qualitatively assessing the effectiveness of DBS therapy.

Quantitative measurements to gauge the effectiveness of SCS therapy are not known to be in widespread use, but several quantitative measurements of pain exist that could be used to gauge therapy effectiveness in an SCS system. Quantitative measurements rely on objective measurements taken from a patient. Examples of objective measurements that have shown promise as reliable indicators of pain include: brain wave measurements (such as taken from a Electroencephalograph (EEG)); neural response measurements (which may be deduced from Evoked Compound Action Potentials (ECAPs)); patient activity or posture measurements (which may be measured using an accelerometer or other activity sensor); galvanic skin resistance measurements; heart rate, heart rate variability, and/or EKG measurements; patient temperature measurements; sleep data measurements; blood flow measurements (such as taken from a photoplethysmogram (PPG)), biochemical sensor measurements; etc..

Other quantitative measurements may include medication dosing information. For example, an SCS patient may be taking pain medications concurrent with SCS therapy. Because the dosing of pain medication taken should scale inversely with pain, such dosing can be used as a quantitative measurement of pain. The amount of pain medication taken can be measured by automated means, such as by including electrical sensors in each of the patient's pain pills. See Proteus Discover™ by Proteus Digital Health, Inc. , as described at http://www. mobihealthnews. com/ content/ california- hospital- becomes- first- us- prescribe-ingestible- sensors- proteus (Jan. <NUM>, <NUM>).

Some of these quantitative measurements can be taken by the same SCS IPG or ETS device that provides the therapy. For example, ECAPs can be sensed in an SCS IPG or ETS (see <CIT>, <CIT>), as can heart rate (see <CIT>). Patient posture and activity can be sensed in an SCS IPG (see <CIT> and <CIT>). Other quantitative measurements may be taken using devices or systems independent of the SCS system. For example, brain waves can be measured using an Electroencephalography (EEG) system; ECAPs can be measured using an Electromyography (EMG) system; blood flow can be measured using a finger probe; patient posture and activity can be measured using an accelerometer in a FitBit™ wearable activity monitor or the patient's cell phone; sleep data can be measured using any of the pieces of equipment used during a Polysomnography analysis (sleep study), or by other activity monitoring devices; etc..

Quantitative measurements to gauge the effectiveness of DBS therapy are also not known to be in widespread use, but similar sensors can provide evidence of effectiveness in a DBS system.

Both qualitative and quantitative measurements have shortcomings when gauging the effectiveness of therapy. Qualitative measurements of effectiveness are inherently suspect because of their subjective nature, and because they lack the precision to provide a fuller indication of therapy effectiveness. For example, in the SCS context, one patient may simply have a low pain tolerance, and may provide (e.g., per NRS) a pain rating of <NUM>, while another patient with a higher pain tolerance might provide a <NUM>. In another example, a patient might indicate prior to receiving SCS therapy that his pain is a <NUM>, and that after receiving SCS therapy his pain is a <NUM>. It would not seem in this instance that SCS therapy has been significantly effective for the patient. However, despite these pain rankings, the patient may be receiving significant benefit from the therapy. For example, prior to receiving therapy the patient may report that a large portion of his back hurt, thus limiting his activity. After receiving therapy, the patient may report that only a small portion of his back hurts (albeit still significantly), which nonetheless allows him to be significantly more active than before. The qualitative measurement of pain is in this example too simple to tell the entire story of patient wellness.

Quantitative measurements may also not provide an accurate indication of the effectiveness of therapy. Assume two patients each reporting a qualitative pain score of <NUM> prior to receiving SCS therapy, and after receiving therapy that the activity of each is monitored (using an IPG-based or an external accelerometer for example) as a quantitative measurement of SCS efficacy. The first patient might report that his pain level is down to a <NUM> after receiving therapy. This first patient may however also be sedentary even though his pain has been relieved, and thus the quantitative measurement of his activity may be very low. While therapy is effective for this patient, such effectiveness is not well reflected in the quantitative measurement of activity. The second patient might report that her pain level is still at a <NUM> after receiving therapy, suggesting that therapy is not effective. This second patient may however be very active after receiving therapy. In effect, this second patient may have chosen to trade pain relief for activity. That is, the therapy may be providing good relief, and allows the patient to increase his activity level, despite no change in the patient's pain score. Thus, while activity may generally comprise a sensible quantitative measurement to gauge the effectiveness of SCS therapy, it is not reliable in all cases and may not be effective for all patients.

It is therefore difficult to universally establish qualitative or quantitative measurements that can gauge the effectiveness of therapy for all patients. In recognition of this fact, a system is disclosed which allows for modelling the wellness of a given IPG patient. The modelling, embodied in an algorithm, uses one or more qualitative measurements and one or more quantitative measurements taken from the patient. The algorithm correlates the qualitative measurements to the various quantitative measurements to eventually, over time, learn which quantitative measurements best correlate to the qualitative measurements provided by the patient. The algorithm can then using current quantitative measurements predict a wellness factor or score for the patient, which is preferably weighted to favor the quantitative measurements that best correlate to that patient's qualitative assessment of therapy effectiveness. Additionally, the wellness factor may be used to adjust the stimulation program that the IPG device provides to the patient.

<FIG> shows an example of a system in which the wellness modelling algorithm <NUM> can be employed. In this example, the wellness modelling algorithm <NUM>, and its computation of a wellness factor Z for the patient, is embodied in an external controller <NUM>, which may generally be similar to the patient external controller <NUM> described earlier (<FIG>). However, embodying the algorithm <NUM> in a patient external controller <NUM> is not strictly necessary, as described further below. Preferably the wellness modelling algorithm <NUM> operates as firmware, software or microcode operable in the control circuitry <NUM> of the external controller <NUM> as described earlier.

The wellness modelling algorithm <NUM> receives one or more qualitative measurements X1, X2, etc. In the example shown, a patient can enter such qualitative measurements using the Graphical User Interface (GUI) <NUM> of the external controller <NUM>, as shown in <FIG>. GUI <NUM> shows a "Wellness Menu" on screen <NUM>, which may have been entered by selecting this menu previously in the GUI <NUM>. The Wellness Menu allows the patient, using interface elements such as buttons <NUM>, to input one or more qualitative measurements at inputs <NUM>. In this example, a first qualitative measurement X1 comprises a pain scale, such as the NRS scale described earlier. A second qualitative measurement X2 comprises a general wellness scale, which again may range from <NUM>-<NUM>, and which may generally inquire as to the patient's well being, as opposed to their pain per se. More or different qualitative measurements could be input as well. The patient may enter such qualitative measurement inputs <NUM> at any time, and on any particular time scale. It might be expected that the patient might enter such qualitative measurements once or twice a day, but as this depends on the patient, such regularity cannot be guaranteed.

Returning to <FIG>, the wellness modelling algorithm <NUM> also receives one or more quantitative measurements of pain, i.e., Y1, Y2, etc. As noted earlier, such quantitative measurements can come from various sensors taking measurements from the patient, and as described earlier can comprise sensors within the IPG <NUM> or ETS <NUM> (therapy sensors <NUM>), or sensors separate from such therapy devices (external sensors <NUM>). Quantitative measurements taken from therapy device sensors <NUM> would preferably be wirelessly communicated from the IPG <NUM> or ETS <NUM> to the external controller <NUM>, while quantitative measurements taken from external sensors <NUM> could be wirelessly transmitted or sent to the external controller <NUM> via a wire or cable. For example, the external sensors <NUM> could connect to a port <NUM> (<FIG>) on the external controller <NUM>. Although not shown, external sensors <NUM> can also be contained within the external controller <NUM> itself. For example, the external controller <NUM> may have an accelerometer capable of monitoring patient activity as a quantitative measurement. External sensors <NUM> may also more generally comprise a source of other quantifiable measurements relevant to therapeutic effectiveness. For example, drug dosing information may be said to come from an external sensor <NUM>, even if information does not comes from a traditional sensor that measures the patient. In this example, drug dosing information may be entered by the patient into a computer acting as a sensor <NUM>.

Returning again to <FIG>, the quantitative measurements that the wellness modelling algorithm <NUM> uses may be specified or reviewed by the patient at interface aspect <NUM>. For example, the patient may select a link at aspect <NUM> that instructs the patient how to connect ("handshake") the relevant sensors <NUM> or <NUM> to the external controller <NUM>, be they wired or wireless. Aspect <NUM> may also show the quantitative measurements the algorithm <NUM> will use after they have been selected. In the example shown, the algorithm <NUM> will use three different quantitative measurements: Y1, indicative of heart rate variability; Y2, indicative of a sleep-related parameter, and Y3, indicative of the magnitude of neural response to stimulation (e.g., ECAP response).

Returning to <FIG>, the wellness modelling algorithm <NUM> receives the qualitative measurement(s) (Xi) and the quantitative measurement(s) (Yi), and uses them to compute a wellness factor Z. Wellness factor Z may be viewable on the GUI <NUM> of the external controller <NUM> in the Wellness Menu, as shown at interface aspect <NUM> in <FIG>. As shown in <FIG>, the wellness factor Z may also be communicated to other external devices, such as a clinician programmer <NUM>, which may be similar to the clinician programmer <NUM> described earlier (<FIG>), and which may also be used to render a GUI similar to that shown in <FIG>. Communication between the external controller <NUM> and the clinician programmer <NUM> can occur wirelessly as described earlier (<FIG>), or by a wired connection. There can be benefit to a clinician's review of the wellness factor Z, and the wellness modeling algorithm <NUM> can send other data to the clinician programmer as well, as explained further below. Wellness factor Z can also be communicated to a network <NUM>, such as the Internet, making it reviewable on a computer <NUM> connected to the network <NUM>. For simplicity, further reference to the clinician programmer <NUM> should be understood to include such other computers <NUM> and networks <NUM>.

It is preferred that the qualitative measurement(s) (Xi) and the quantitative measurement(s) (Yi) are received at the patient external controller <NUM>. This is preferred because the external controller <NUM> is device is generally proximate to (e.g., carried by) the patient, and hence proximate to the sensors <NUM> and <NUM> which are also generally proximate to the patient, such that the sensors can easily communicate such measurements to the external controller <NUM>. This allows measurements to be taken and the wellness modelling algorithm <NUM> to operate on a continual basis, and preferably as the patient goes about his daily activities. However, and although not shown, the qualitative measurement(s) (Xi) and the quantitative measurement(s) (Yi) can be received at other external devices such as the clinician programmer <NUM> or even the IPG <NUM> or ETS <NUM> itself. As discussed further below, the wellness modelling algorithm <NUM> may be embodied in these other devices.

<FIG> shows an example of qualitative and quantitative measurements as received by the wellness modelling algorithm <NUM>. In this example, three quantitative measurements Y1, Y2 and Y3 are used. These quantitative measurements may comprise any of the quantitative measurements described earlier, and may be taken from the therapy device sensor <NUM> or the external sensors <NUM>. Notice that the sensors report their measurement data to the algorithm <NUM> at different rates: Y3 reports more frequently than does Y1, and Y1 reports more frequently than does Y2. Such variability in measurement reporting frequency may depend on the sensors being used. The algorithm <NUM> may also receive or process (e.g., average) reported quantitative measurements at a constant rate. Although the quantitative measurements Yi are shown as periodic, this is not required, and instead they can be reported to the algorithm <NUM> at random times. Furthermore, some sensors may only be worn or used by the patient at certain times (e.g., during the day), meaning that those sensors would not report measurements at other times (e.g., at night).

Notice that the reported quantitative measurements Yi may differ in their magnitudes. This depends on the sensor <NUM> or <NUM> used, and the quantities they measure. Y1, comprising heart rate variability for example, may vary from <NUM>-<NUM> beats per minute. Y2 may comprise some quantitative sleep parameter, which happens to vary from <NUM> to <NUM>. Y3 may comprise a measured magnitude of ECAP neural responses, which may range from <NUM> to <NUM> Volts. Such variability in the magnitude of the reported quantitative measurements Yi will not affect the operation of the wellness modelling algorithm <NUM>. However, if necessary or useful, the various quantitative measurements Yi can be normalized by the algorithm <NUM>. For example, to arrive at quantitative measurements that only vary from <NUM> to <NUM>, Y1's measurements (ranging from <NUM> to <NUM>) can be scaled by a factor of <NUM>; Y3's measurements (ranging from <NUM> to <NUM>) can be scaled by <NUM>; Y2 (which already ranges from <NUM> to <NUM>) may simply not be scaled (i.e., scaled by a factor of <NUM>).

In the example of <FIG>, only one qualitative measurement X is used, although as mentioned above a plurality of qualitative measurements could also be processed by the wellness modelling algorithm <NUM>. Qualitative measurement X may comprise for example a NRS pain score, and as described above can be entered by the patient into the GUI <NUM> of their external controller <NUM> (<FIG>, <NUM>). Even if the patient is instructed by his clinician to enter such qualitative measurements X on a schedule (e.g., twice a day), notice that such qualitative measurements X may be entered at random times. Further, as mentioned above, it might be expected that a patient would enter qualitative measurements X much less frequently than the quantitative measurements Yi would be reported. For example, while qualitative measurements X might be entered on a time scale of hours or days, quantitative measurements Yi might be reported on a scale of seconds or minutes.

Preferably, the wellness modelling algorithm <NUM> will store each qualitative (Xi) and quantitative (Yi) measurement it receives along with a timestamp so that the algorithm <NUM> can know at which time each data point is received. Associating each measurement with a timestamp can be useful for many reasons, but in one example, the algorithm <NUM> when performing its calculations may ignore measurements that fall outside of a window <NUM> of time. In other words, the algorithm may ignore measurements that are too old to be useful. This is sensible, because a patient's circumstances can change over time, making older data less reliable to consider. For example, the patient may over time have significantly changed the stimulation program the IPG <NUM> or ETS <NUM> is running, or may have healed or formed scar tissue, or may have reduced the level of pain medication he is taking, etc. In one example, window <NUM> may comprise a time period of a month, and thus the wellness modelling algorithm <NUM> will discard any data with a time stamp older than this duration.

The wellness modelling algorithm <NUM> seeks to determine how well each quantitative measurement Y1, Y2, and Y3 correlates to the qualitative measurement X entered by the patient, which then allows the algorithm to compute a wellness factor Z. Preferably, wellness factor Z is determined or weighted to favor the quantitative measurements that best correlate to X, as discussed in detail below. It should be noted that that are several manners of establishing correlations between the quantitative measurements Y1, Y2, and Y3 and qualitative measurement X. However, for purposes of a simple illustration, it is assumed that the wellness modelling algorithm <NUM> will determine correlation using a linear regression analysis.

<FIG> shows graphs correlating X with Y1 (<NUM>(<NUM>)), with Y2 (<NUM>(<NUM>)), and with Y3 (<NUM>(<NUM>)). The data points in each graph are preferably only determined based on qualitative and quantitative measurements falling within window <NUM>, and such data points can be determined in different ways. Consider data points <NUM>, each associated with a qualitative measurement X=<NUM>. As shown in <FIG>, these data points <NUM> can be established by determining the value of the quantitative measurements Y1=<NUM>, Y2=<NUM> and Y3=<NUM> that immediately preceded the entry by the patient of X=<NUM>. Therefore, graph <NUM>(<NUM>) includes a data point <NUM> at (<NUM>, <NUM>), graph <NUM>(<NUM>) includes a data point <NUM> at (<NUM>, <NUM>), and graph <NUM>(<NUM>) includes a data point <NUM> at (<NUM>, <NUM>).

The data points in graphs <NUM> may be determined in different manners. For example, data point <NUM> in graph <NUM>(<NUM>), occurring at qualitative measurement X=<NUM>, is established by associating this qualitative measurement with the average of the two preceding quantitative measurements (Y1=<NUM> and <NUM>). Thus, graph <NUM>(<NUM>) includes a data point <NUM> at (<NUM>, <NUM>). In other words, some number of quantitative measurements can be averaged and associated with each qualitative measurement to determine the data points in the graphs, such as a certain number of preceding quantitative measurements, preceding quantitative measurements over a certain time period, all preceding quantitative measurements since a last qualitative measurement, etc. A qualitative measurement can likewise be associated with one or more quantitative measurements that are subsequent to the qualitative measurement, or quantitative measurements that are both preceding and subsequent.

Returning to <FIG>, once the data points in each graph <NUM>(<NUM>)-(<NUM>) are established by the wellness modelling algorithm <NUM>, the algorithm <NUM> can determine a regression line <NUM>(<NUM>)-(<NUM>) for each. Regression lines <NUM>(<NUM>)-(<NUM>) in this example are determined using linear regression, such as by a least-squares linear regression, although other line-fitting techniques can be used, including non-linear fitting techniques.

Also determined by the algorithm <NUM> as part of its regression analysis is a correlation coefficient Ri that quantifies how well each quantitative measurement Yi is correlated to the qualitative measurement X (and thus how well each regression line <NUM> fits the data points). Correlation coefficient Ri in these examples ranges from -<NUM> (a perfect negative correlation) to +<NUM> (a perfect positive correlation), with a value of zero denoting no correlation whatsoever. Thus, it is seen that correlation coefficient R1 = <NUM> for graph <NUM>(<NUM>) suggests almost no correlation between quantitative measurement Y1 (e.g., heart rate variability) and qualitative measurement X for the patient in question. By contrast, correlation coefficient R2 = -<NUM> for graph <NUM>(<NUM>) suggests a strong (negative) correlation between quantitative measurement Y2 (e.g., a sleep parameter) and qualitative measurement X for the patient in question. The correlation coefficient R3 = <NUM> for graph <NUM>(<NUM>) suggests a weak (positive) correlation between quantitative measurement Y3 (e.g., magnitude of ECAP neural response) and qualitative measurement X for the patient in question.

To summarize, the wellness modelling algorithm <NUM> has to this point determined that quantitative measurement Y2 best correlates to this patient's subjective sense of therapy effectiveness as reflected by qualitative measurement X, followed by quantitative measurement Y3, and followed further by quantitative measurement Y1. Note that this is not a universal determination that Y2 correlates well and Y1 correlates poorly for all patients, but is instead a conclusion the wellness modelling algorithm <NUM> reaches that is specific to the patient in question and at a particular point in time. For example, the wellness modelling algorithm <NUM> might determine for another patient that quantitative measurement Y1 best correlates to their qualitative measurement of X. In other words, the wellness modelling algorithm <NUM> is specific to, and learns using measurements from, a specific patient, which increases its reliability.

With the correlations between the quantitative measurements Yi and the qualitative measurements X established, the wellness modelling algorithm <NUM> may now determine a wellness factor Z. The wellness factor Z can be determined based on reported quantitative measurements alone. Preferably, the wellness factor is determined using recently-received quantitative measurements, shown in <FIG> as data points <NUM>. Data points <NUM> comprise the current (or immediately preceding) reported values for quantitative measurements Y1, Y2, and Y3 (Y1c, Y2c, and Y3c, with subscript 'c' denoting 'current'). However, as before, current quantitative measurements Yic can also comprise an average of some number of preceding or subsequent values for Yi. Using just immediately-preceding single data points for each as shown in <FIG>, it is seen that Y1c = <NUM>, Y2c = <NUM>, and Y3c = <NUM>.

The wellness modelling algorithm <NUM> can then use the regression lines <NUM>(<NUM>), <NUM>(<NUM>), and <NUM>(<NUM>) to estimate a qualitative measurement E1, E2, E3 for each. As <FIG> shows, this comprises solving each regression line <NUM>(i) for Ei at the given Yic. In the example shown, the following estimated qualitative measurements result: E1 = <NUM>, E2 = <NUM>, and E3 = <NUM>. Generally speaking, each of these values Ei are an estimate of the qualitative measurement X that would be expected given the current quantitative measurement Yic.

The wellness modelling algorithm <NUM> then uses the estimated qualitative measurements Ei to arrive at a single wellness factor Z. Preferably, the wellness factor Z attributes more significance or weight to estimated qualitative measurements Ei having higher correlation coefficients Ri. This can be achieved in different manners. In example <NUM>, each estimated value Ei is weighted by multiplying it by the absolute value of its correlation coefficient Ri, and these products are summed (i.e., |R1|*E1 + |R2|*E2 + |R3|*E3). This ensures that the estimated value E2 (corresponding to the highest-correlated quantitative measurement Y2 for the patient) is given more significance in the overall sum of the products, while E1 (corresponding to the lowest-correlated quantitative measurement Y1) contributes little to the sum. The sum of the products can be divided by the sum of all of the correlation coefficients (i.e., by |R1|+|R2|+|R3|) to normalize the result. This results in example <NUM> in the calculation of a wellness factor Z = <NUM>. Notice that this value is sensibly close to the estimated qualitative measurement E2 = <NUM> for the most highly-correlated quantitative measurement Y2.

Example <NUM> is similar to example <NUM>, but simply omits from the wellness factor Z determination the least-relevant estimated qualitative measurement E1, that is, the estimate corresponding to the lowest-correlated quantitative measurement Y1. Thus, only estimates E2 and E3 are multiplied by their correlation coefficients R2 and R3 (i.e., |R2|*E2 + |R3|*E3), and normalized (divided by |R2|+|R3|). A wellness factor of Z = <NUM> results, which is sensibly between the estimated values E2 and E3 corresponding to the remaining quantitative measurements Y2 and Y3. Exclusion of an estimated qualitative measurement Ei from the wellness factor Z determination can be made in different ways. For example, the least relevant (worst correlated) can be discarded as in example <NUM>, or the two least relevant can be discarded, etc. Also, exclusion of an estimated qualitative measurement can be determined based on a cut-off: for example, all estimates Ei associated with a correlation coefficient Ri less than <NUM> could be excluded as too poorly correlated to be useful, etc. Example <NUM> further illustrates that, over time as statistical relevance becomes clear, quantitative measurements like Y1 that correlate poorly with the patient's qualitative measurement X can simply be dispensed with, i.e., the patient will no longer need to wear sensors that take those measurements.

Example <NUM> determines wellness factor simply as the estimated qualitative measurement E2 of the quantitative measure Y2 that best correlates to the input qualitative measure X. Again, this suggests that quantitative measurements Y1 and Y3 can simply be dispensed with. Instead, the patient may then only need a sensor to quantitatively measure Y2, which can then be used alone to determine the wellness factor Z. In this regard, notice that implementation of the wellness modeling algorithm <NUM> does not necessarily require the use of more than one quantitative measures Yi. Instead, only a single quantitative measure Y may be used to determine wellness factor Z, particularly if that single quantitative measurement Y has been learned by the algorithm <NUM> to have significant correlation with qualitative measure X.

Example <NUM> shows another method by which the wellness modelling algorithm <NUM> can determine wellness factor Z. In this example, the estimated qualitative measurement (E2) corresponding to the highest-correlated quantitative measurement (Y2) is used as the basis for the calculation, and thus comprise the first factor in the sum. However, that estimated value E2 is pulled higher or lower based on the other estimated values (E1 and E3) with a strength dependent on their respective correlation coefficients (|R1| and |R31). For example, a difference E1-E2 can be calculated. Because this difference is positive (<NUM>-<NUM>=<NUM>), E1 will pull the wellness factor Z higher from its base value E2, in accordance with a weighting as set by their correlation coefficients (i.e., +(E1-E2)*[|R1|/(|R1|+|R2|)]). Likewise, a difference E3-E2 can be calculated. Because this difference is negative (<NUM>-<NUM>=-<NUM>), E3 will pull the wellness factor Z lower from its base value E2, again in weighted fashion (i.e., +(E3-E2)*[|R3|/(|R3|+|R2|)]). The result is a wellness factor of Z = <NUM>.

Example <NUM> shows another method for determining wellness factor Z that is similar to example <NUM>, but multiplies |R1| and |R3| by <NUM> in the weighting factors. In this way, as |R1| or |R3| approaches |R2|, the weighting factors <NUM>|R1|/(|R1|+|R2|)] and <NUM>|R3|/(|R3|+|R2|)] will approach <NUM>.

Again, there are many ways wellness modelling algorithm <NUM> can determine wellness factor Z after determining the relevance of each of the quantitative measurements Yi for the patient, and examples <NUM>-<NUM> should be understood as non-limiting.

In the examples shown to this point, notice that the wellness factor Z will vary, or can be constrained to vary, in the same range as the qualitative measurement X. That is, just as qualitative measurement X can range from <NUM> to <NUM>, so too can Z range from <NUM> to <NUM>. However, this is not strictly necessary, and the range of wellness factor Z can differ from the range allowed for the qualitative measurement X. Wellness factor Z is shown in the illustrated example to increase when wellness decreases, but again this is not necessary and instead an increasing Z can indicate increasing wellness. Wellness factor Z may be viewable on the GUI <NUM> of the external controller <NUM> in the Wellness Menu, as shown at interface aspect <NUM> in <FIG>.

Although not illustrated, it should be understood as mentioned earlier that more than one qualitative measurement-e.g., X1 and X2-can be used in the wellness modeling algorithm. In that circumstance, the correlation of each quantitative measurement Yi can be correlated to both X1 and X2, with the wellness factor Z computed as a function of such correlations, and again preferably favoring the quantitative measure with the best correlation. Such multivariable correlation techniques are well known and not illustrated for simplicity.

Further, the wellness modelling algorithm <NUM> may employ other techniques to compute the wellness factor. For example, the qualitative measurement Xi and the quantitative measurements Yi can be analyzed and a wellness factor Z determined using weighted linear techniques, other linear or non-linear optimization techniques, principal component analysis techniques, artificial neural network techniques, support vector machine method techniques, other machine learning or artificial intelligence (AI) techniques, etc..

Still further, and although not depicted in the examples <NUM>-<NUM> of <FIG>, the wellness factor Z may also be determined, at least in part, as a function of the qualitative measure X, for example by using X as last entered by the patient X and particularly if X was relatively recently entered by the patient. For example, X may be assigned a higher weight in the calculation of Z if X was entered recently in time.

Preferably, the wellness modelling algorithm <NUM> will determine the wellness factor Z as a function of time. It may determine Z with a set period, such as every ten minutes. Or, it may determine Z any time a new qualitative measurement Xi or quantitative measurement Yi is received. Beneficially, and assuming sensors <NUM> and <NUM> can report quantitative measurements Yi at a high rate, the wellness modelling algorithm <NUM> can compute Z on a much shorter time scale than the patient might otherwise enter their assessment of wellness via the qualitative measurement Xi. This allows the algorithm <NUM> to compute the wellness factor Z even during periods when the patient has not (recently) entered any qualitative measurements Yi, thus providing a generally continuous indication of patient wellness. The wellness factor Z may also be automatically produced at the patient's request, such as by selecting the "compute" input of interface aspect <NUM> (<FIG>).

In another example, the wellness modelling algorithm <NUM> can compute wellness factor Z as a function of the received quantitative measurements Yi, and in particular as a function of the patient's current quantitative measurements Yic. This may be in addition to also computing the wellness factor Z as a function of the qualitative measurements Xi via their estimations Ei.

It should be understood that the determined wellness factor Z can be indicative of the status of the patient as gauged by the qualitative measurements Xi. Such patient status can comprise a qualitative measurement of a primary symptom that the medical device is configured to directly treat. For example, in an SCS system designed to treat a primary symptom of pain, at least one qualitative measurement X can include a patient's rating of pain, using the various pain scales described earlier. The wellness factor Z that the wellness modelling algorithm <NUM> determines will then be indicative of the severity of patient pain. Patient status can also comprise a qualitative measurement of secondary symptoms related to a patient's primary symptom. For example, pain in an SCS patient may be causing depression, anxiety, or other secondary symptoms. By providing at least one qualitative measurement X rating a secondary symptom (e.g., depression), the wellness modeling algorithm <NUM> will provide a wellness factor indicative of the severity of that secondary symptom. Providing qualitative measurements Xi ranking both pain and depression will produce a wellness factor Z indicative of both of these statuses, etc. The status of the patient need not comprise a symptom per se, but may more generally comprise some other measure of a patient's wellbeing. For example, the patient could provide as a qualitative measurement information rating their happiness, activity level (here as a qualitative measurement, although activity level can also comprise a quantitative measurement as described earlier), ability to work, or any other relevant status that therapy might effect. In such a case, the wellness factor Z comprises a means of quantifying such statuses.

If the wellness factor Z is computed as a function of the received quantitative measurements Yi, wellness factor Z can also be indicative of that particular quantitative measure at least in part. For example, wellness factor Z might in this example be indicative of both pain as a qualitative measurement X and heart rate as a quantitative measure Y.

The wellness modelling algorithm <NUM> may implicate other parts of the system beyond the patient external controller <NUM>. For example, <FIG> shows two manners in which the wellness modeling algorithm <NUM> can communicate with, or be distributed between, the external controller <NUM> and the clinician programmer <NUM> (which again can comprise other networks <NUM> or computer <NUM>; <FIG>). In <FIG>, the wellness modelling algorithm <NUM> resides in the external controller <NUM>, but can communicate relevant data with the clinician programmer <NUM>. In this example, the wellness modelling algorithm <NUM> computes the wellness factor Z at the external controller <NUM>, but transmits the computed wellness factor Z to the clinician programmer <NUM>. The external controller <NUM> may also transmit the qualitative measurements Xi entered by the patient and quantitative measurements Yi received from the sensors <NUM> and <NUM> (not shown).

Alternatively, the wellness modelling algorithm <NUM> may be embodied in the clinician programmer <NUM>, as shown in <FIG>. Preferably the wellness modelling algorithm <NUM> comprises firmware, software, or microcode operable in the clinician programmer <NUM>'s control circuitry <NUM> as described earlier. In this example, the external controller <NUM> preferably collects the qualitative measurements Xi and the quantitative measurements Yi, and then transmits them to the clinician programmer <NUM>, although the clinician programmer <NUM> can also receive Xi and Yi directly (not shown). The wellness modelling algorithm <NUM> at the clinician programmer can then determine the wellness factor Z from the data Xi and Yi.

In short, the wellness modelling algorithm <NUM> can be split between the external controller <NUM> and the clinician programmer <NUM>, with any relevant data transferred from one to the other. In another example, once the clinician programmer <NUM> has computed wellness factor Z, Z may be transmitted from the clinician programmer to the external controller <NUM> so that Z can be reviewed by the patient (<FIG>, <NUM>).

In either case, it can be useful to have the wellness factor Z, and measurements Xi and Yi, at the clinician programmer <NUM>. This can allows for example the clinician to ensure that the sensors <NUM> and <NUM> are working properly-i.e., that the values received for qualitative measurements Yi are appropriate. Reviewing wellness factor Z can also be clinically useful. Assume as shown in the graph of <FIG> that the clinician programmer <NUM> is used to graph wellness factor Z as a function of time, and to present these results on its user interface. The clinician may notice that wellness factor Z has been relatively low and stable for a period of time, but recently (<NUM>) has increased. It may be useful in that circumstance for the clinician to reach out to the patient to determine the reason or to suggest modifications to SCS therapy. For example, perhaps the patient would benefit from adjusting the stimulation program the IPG <NUM> or ETS <NUM> is running. Note that reaching out to the patient may be especially useful if the patient hasn't recently entered qualitative measurements X which would otherwise indicate the patient's qualitative assessment of their wellness. The graph of <FIG> could be provided on the user interface of the external controller <NUM> as well, and could be graphed to include the wellness factor Z, and either or both of the qualitative measurements Xi and the quantitative measurements Yi.

The wellness modelling algorithm <NUM> may also be distributed between the external controller <NUM> and the IPG <NUM> or ETS <NUM> that provides SCS therapy. Furthermore, the wellness modelling algorithm <NUM> may be used to control the stimulation program (SP) that the IPG <NUM> or ETS <NUM> is running in a closed loop fashion. For example, in <FIG>, the wellness modelling algorithm <NUM> operates within the control circuitry <NUM> of the IPG <NUM> or ETS <NUM>. Control circuitry <NUM> may comprise a microcontroller, and may be similar to the control circuitries <NUM> and <NUM> described earlier. Control circuitry <NUM> may also comprise a part of, or communicate with one or more Application Specific Integrated Circuits (ASICs), as described in <CIT>, <CIT>, and <CIT>. Such ASIC(s) may include the stimulation circuitry <NUM> and <NUM> in the IPG <NUM> or ETS <NUM>.

The algorithm <NUM> receives qualitative measurements Xi that the patient has entered into his external controller <NUM>, preferably wirelessly as described previously (<FIG>) although a wired connection could also be used between the external controller <NUM> and the ETS <NUM>. Likewise, the external controller <NUM> can transmit to the IPG <NUM> or ETS <NUM> qualitative measurements Yi that it has received from external sensors <NUM> (<FIG>). Although not shown in <FIG>, it should be understood that the algorithm <NUM> can also receive quantitative measurements Yi from any therapy sensors <NUM> (<FIG>) embodied in the IPG <NUM> or ETS <NUM>. As before, the wellness modelling algorithm1 <NUM> can compute a wellness factor Z.

The wellness factor Z can in turn be used to adjust the stimulation program (SP) the IPG <NUM> or ETS <NUM> is executing, thus allowing the wellness factor Z to be used as a means of closed loop control. In this regard, the wellness factor Z can be reported to stimulation programming control circuitry <NUM> within the control circuitry <NUM> that is used to generate and send the stimulation program to the stimulation circuitry <NUM> or <NUM> in the IPG <NUM> or ETS <NUM>. Normally the circuitry <NUM> receives the stimulation program or adjustments thereto from the external devices <NUM> and <NUM>, and formats the data in a manner interpretable by the stimulation circuitry <NUM> or <NUM> in the IPG <NUM> or ETS <NUM>. The stimulation circuitry <NUM>/<NUM> as described earlier can then form stimulation with the prescribed stimulation parameters (e.g., amplitude, frequency, pulse width, electrode polarity) at the electrodes <NUM> selected for stimulation.

The wellness factor Z can be used to adjust one or more of the stimulation program's parameters, or to pick a wholly new stimulation program to execute through use of a stimulation optimization algorithm <NUM>. In the example shown, the stimulation optimization algorithm <NUM> is embodied in the stimulation programming control circuitry <NUM>, although it could reside elsewhere. Stimulation optimization algorithm <NUM> can also comprise part of the wellness modelling algorithm <NUM>, although it is shown separately for ease of illustration.

As shown in <FIG>, the stimulation optimization algorithm <NUM> can assess wellness factor Z, and if not optimal can change the stimulation program otherwise prescribed for the patient. For example, and assuming a high value for Z indicates poor wellness, the stimulation optimization algorithm <NUM> can compare Z to a threshold, and if above that threshold, can increase the amplitude of the stimulation program in the hope that increased amplitude will better mask the patient's symptoms (e.g., pain). Algorithm <NUM> can also more generally scale the amplitude with the wellness factor Z, or may change other stimulation parameters. Algorithm <NUM> may also choose a new stimulation program for the patient. If wellness factor Z is optimal, the algorithm <NUM> may simply allow the prescribe stimulation program to be executed by the stimulation circuitry <NUM> or <NUM>. Note that assessment of the wellness factor Z (<NUM>) may occur over some period of time before the stimulation optimization algorithm <NUM> will indicate that stimulation might be adjusted. This allows the wellness modelling algorithm <NUM> time to establish reasonable correlations and provide a reliable value for the wellness factor Z as discussed previously, or may similarly allow the stimulation optimization algorithm <NUM> time to draw its necessary correlations.

The manner in which the stimulation optimization algorithm <NUM> can adjust the stimulation program given Z can be more complex. For example, the circuitry <NUM> can over time establish a correlation between the stimulation program (or its parameters) and Z, to determine what programs or parameters have an effect on Z so that the stimulation program can be automatically changed to try and adjust Z to an optimal value. This is particularly useful because while the stimulation program can be changed as a function of Z, it can also be changed by the patient or the clinician using external devices <NUM> or <NUM>, and so algorithm <NUM> can over time start to learn a correlation between stimulation programs or parameters and Z.

In another example, the stimulation optimization algorithm <NUM> can receive quantitative measurements Yi, and in particular can receive the patient's current quantitative measurements Yic, as shown in the dotted-lines arrow in <FIG>. This allows the algorithm <NUM> to understand a patient's current or recent physical state in additional to the estimated wellness factor Z. The algorithm <NUM> can then adjust the stimulation program as a function of both Z and quantitative measurements Yic. As with Z, Yi can be correlated with different stimulation programs or stimulation parameters, which can then be used by algorithm <NUM> to adjust stimulation, and hopefully optimize Z, for the patient's current state as reflected by Yic.

Use of the wellness factor Z to adjust the executed stimulation program is also particularly useful because the stimulation program may be sub-threshold-i.e., at a level that the patient can't directly feel. In this circumstance, it may be difficult for the patient to provide feedback concerning the effect of changes in the stimulation program, and so the combination of qualitative measurements Xi and quantitative measurements Yi provide a means for quantifying such effects that are otherwise difficult to determine.

The stimulation optimization algorithm <NUM> may not automatically adjust the patient's stimulation program, but may instead first seek confirmation from the patient (or clinician) that it is authorized to make the adjustment. Thus, as shown in <FIG>, if the algorithm <NUM> determines that wellness factor Z is not optimal, the algorithm <NUM> may send a request to change the stimulation program (CSP) signal to an external device, such as the patient external controller <NUM>. If signal CSP is received at the external controller <NUM>, the user may be prompted that his stimulation program may be adjusted, such as at interface aspect <NUM> of the Wellness Menu (<FIG>). Upon receiving this prompt, the user may then choose to allow the algorithm <NUM> to change the stimulation program (Y/N), which response can be wirelessly communicated to the IPG or ETS. In a more complicated example, the algorithm <NUM> can additionally transmit to the external device the specific changes in the stimulation program it is recommending, i.e., how the algorithm <NUM> proposes to change amplitude, pulse width, frequency, etc. Communication of CSP to a relevant external device is not shown in subsequent examples for simplicity, but could be used in such examples as well.

<FIG> shows another example in which the wellness modeling algorithm <NUM> is in the external controller <NUM>, but transmits the determined wellness factor Z to the IPG <NUM> or ETS <NUM>. Such transmission can occur on a periodic basis or whenever Z is calculated, and whenever the external controller <NUM> is coupled for communication with the IPG <NUM> or ETS <NUM>. The stimulation optimization algorithm <NUM> can then adjust the stimulation program given Z as previously described.

<FIG> show another alternative in which the wellness modelling algorithm <NUM> operates within the clinician programmer <NUM> to determine wellness factor Z, as occurred in <FIG>. In this example, the wellness factor Z can be transmitted to the external controller <NUM>, which in turn can transmit Z to the circuitry <NUM> in the IPG <NUM> or ETS <NUM>. Alternatively, the clinician program <NUM> can directly transmit the determined wellness factor Z to the IPG <NUM> or ETS <NUM>, for example using its antennas 80a or 80b (<FIG>). Again, the stimulation optimization algorithm <NUM> can adjust the stimulation program given Z as previously described.

In <FIG>, the stimulation optimization algorithm <NUM> is embodied in the external controller <NUM> and the clinician programmer <NUM> respectively. In <FIG>, the wellness modelling algorithm <NUM> in the external controller <NUM> determines wellness factor Z and provides it to the stimulation optimization algorithm <NUM> also in the external controller. This allows the external controller <NUM> to determine, or adjust, the stimulation program that the external controller provides to the IPG <NUM> or ETS <NUM> for execution. In <FIG>, the wellness modelling algorithm <NUM> in the clinician programmer <NUM> determines wellness factor Z and provides it to the stimulation optimization algorithm <NUM> also in the clinician programmer. Again, this allows the clinician programmer <NUM> to determine, or adjust, the stimulation program that the clinician programmer provides to the IPG <NUM> or ETS <NUM> for execution. Note that the clinician programmer <NUM> can provide the adjusted stimulation program to the IPG <NUM> or ETS <NUM> via the external controller <NUM>, as shown in dotted lines.

The wellness modelling algorithm <NUM> and the stimulation optimization algorithm <NUM> need not be embodied in the same device in the system. For example, one algorithm may reside in the clinician programmer while the other resides in the external controller <NUM>. More generally, given the communicative connectivity of the various devices in the system, the algorithms <NUM> and <NUM> can be distributed between the clinician programmer <NUM>, the external controller <NUM> and the IPG <NUM> or ETS <NUM> in any fashion. Furthermore, although not shown, algorithms <NUM> and <NUM> may also reside in an external sensor <NUM> (<FIG>).

To this point, aspects of the invention have been illustrated in the context of SCS therapy as useful to curb pain and DBS therapy as useful to curb tremor and neuropsychiatric disorders. However, useful examples of the invention are not so limited, and instead the invention may be used in other contexts in which a medical device's therapy effectiveness in treating a patient's symptoms is gauged using qualitative and quantitative measures to compute a wellness factor, and in which such wellness factor may be used to adjust the therapy that the medical device provides. In this regard, the invention may be used with medical devices that are not implantable. The invention can be used in a Peripheral Nerve Stimulation (PNS) system (whether implantable or not), a Transcutaneous Electrical Nerve Stimulation (TENS) system, and in other stimulation therapy systems. The invention may further be used in medical device systems that provide therapies other than neurostimulation. The invention may also be used to compare the effectiveness of different types of therapies to address a patient's symptoms, or to evaluate multi-modal therapies.

Claim 1:
A medical device system, comprising:
a medical device (<NUM>, <NUM>) configured to execute a program to provide neurostimulation therapy to a patient to alleviate a symptom of the patient;
at least one non-transitory computer readable medium configured to be executed on an external device (<NUM>) configured to adjust the program executed by the medical device; and
the external device,
wherein the at least one non-transitory computer readable medium is stored in the external device, and
wherein the computer readable medium contains instructions for a first algorithm (<NUM>), wherein the first algorithm, when executed on the external device, is configured to:
receive at least one qualitative measurement (X, Xi) from the patient regarding a status of the patient,
receive at least one quantitative measurement (Y, Y1, Y2, Y3, Y4, Y5, Yi) taken from the patient, and
determine a wellness factor (Z) for the patient using the at least one qualitative measurement and the at least one quantitative measurement, wherein the wellness factor is indicative of a severity of the symptom, or is indicative of the status of the patient.