Abstract:
A system and method for providing hierarchical medical device control for automated patient management is presented. A processor is operatively coupled to a plurality of medical devices on a substantially continual basis to receive sensor data. A control strategy is assigned to the processor to specify actions to be taken by the medical devices to affect the attainment of a therapy goal. State is maintained, selected from the group comprising a history of changes to the control strategy and past sensor data received from the medical devices. Feedback is periodically received. The feedback includes new sensor data from the medical devices. The feedback and the state are analyzed against the actions specified in the control strategy. Control is provided to one or more medical device in response to an actionable change from the actions specified in the control strategy.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates in general to automated patient management and, specifically, to a system and method for providing hierarchical medical device control for automated patient management.  
       BACKGROUND OF THE INVENTION  
       [0002]     In general, implantable medical devices (IMDs) can provide in situ therapy or monitoring under preprogrammed autonomous control. Autonomous control is governed by tunable and fixed control parameters, which are physician-selected to meet therapy goals. IMDs must be periodically interfaced to external devices, such as programmers and patient management devices, for physician follow-up. Physicians assess a patient&#39;s current condition based on downloaded patient data and lab or clinical tests, such as electrophysiology tests, treadmill stress tests, and blood work, to determine if treatment goals are being met or whether control parameters require reprogramming.  
         [0003]     IMD therapy is intended to meet specific goals and therapy is selected based upon physician experience and population data for comparable patient outcomes. A therapy goal is implemented by specifying actions to be performed by the IMD under a treatment plan through downloadable control parameters. The medical means for implementing a treatment plan will depend upon the patient profile and medical resources available.  
         [0004]     Progress towards a therapy goal can be gauged in light of the scope of control over and the therapeutic affect made upon a patient. For example, an IMD exercises direct control over a patient. IMD resources are constrained in terms of processing, storage, and power budget. As a result, IMDs can only provide a temporally limited perspective of the efficacy of the therapy provided due to the restricted memory available.  
         [0005]     Implementing goal-directed operation on IMDs can be a challenge. Therapy is directed to patient management at a micro level and IMDs lack the resources to maintain and track progress towards a goal defined more broadly than an event occurrence. Goal-directed patient management is better handled at a macro level as provided on an external device, such as a server or patient management device. External devices allow patient data to be downloaded and tracked over time to build a more comprehensive picture of the patient&#39;s progress and therapy can be adjusted as necessary. Conventional approaches to goal-directed patient management, however, adopt open loop control strategies that require the involvement of a clinician, such as a physician, nurse, or other qualified individual.  
         [0006]     U.S. Pat. No. 6,416,471, issued to Kumar et al. (“Kumar”) discloses a remote patient telemonitoring device. A disposable sensor band with electrode patches detects and transmits vital signs data to a signal transfer unit, which can either be worn or be positioned nearby the patient. The base station receives data transmissions from the signal transfer unit for transferring the collected data to a remote monitoring station. Indications are provided to a patient from the base station when threshold violations occur, but the system requires an operator, such as a physician or nurse, to manually review and provide an interpretation of the patient data.  
         [0007]     U.S. Pat. No. 6,024,699, issued to Surwit et al. (“Surwit”) discloses a central data processing system configured to communicate with and receive data from a plurality of patient monitoring systems, which may implement a medical dosage algorithm to generate dosage recommendations. Blood from a pricked finger may be read on a chemically treated strip. Modifications to medicine dosages, medicine dosage algorithms, patient fixed or contingent self-monitoring schedules, as well as other treatment information are communicated, but screen mechanisms are provided to case managers for ensuring that treatment or information provided is medically sound before communicating that treatment or information to the patient or patient management device.  
         [0008]     U.S. Pat. No. 6, 083,248, issued to Thompson discloses a worldwide patient location and data telemetry system for implantable medical devices. An implanted device telemetry transceiver within the implanted medical device communicates data and operating instructions to and from a medical device in a coded communication. A global positioning system provides data identifying the position of the patient. Should a need to upgrade or change the behavior of implanted devices arise, the system allows the central monitoring site to revise interfaced IMDs by transmitting new programming instructions, assuming appropriate governmental authorities and patients′physicians have agreed to the need for such changes.  
         [0009]     Therefore, there is a need for providing remote patient management with closed loop reporting and control in a hierarchical structure that allows goal and sub-goal delegation and therapy feedback through levels of distributed control.  
       SUMMARY OF THE INVENTION  
       [0010]     A system and method includes a closed loop control hierarchy having two or more levels. The top, or root level, contains a server that centrally manages a control strategy. The penultimate level includes medical devices, such as implantable or external medical devices or sensors, and the bottom, or terminal, level includes their respective sensors and effectors. In one embodiment, the control hierarchy includes an intermediate logical level that includes one or more patient management devices, each dedicated to servicing one or more of the medical devices. Both the server and each patient management device function as controllers over physical plants that can include those devices assigned to children nodes in the control hierarchy. Control is exercised over and feedback is received from the assigned devices. Control is exercised by delegating sub-goals to the assigned devices. Feedback is analyzed against locally-maintained state to identify whether changes to the existing control strategy are necessary.  
         [0011]     One embodiment provides a system and method for providing hierarchical medical device control for automated patient management. A processor is operatively coupled to a plurality of medical devices on a substantially continual basis to receive sensor data. A control strategy is assigned to the processor to specify actions to be taken by the medical devices to affect the attainment of a therapy goal. State is maintained, selected from the group comprising a history of changes to the control strategy and past sensor data received from the medical devices. Feedback is periodically received. The feedback includes new sensor data from the medical devices. The feedback and the state are analyzed against the actions specified in the control strategy. Control is provided to one or more medical device in response to an actionable change from the actions specified in the control strategy.  
         [0012]     Still other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein are described embodiments of the invention by way of illustrating the best mode contemplated for carrying out the invention. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modifications in various obvious respects, all without departing from the spirit and the scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a functional block diagram showing, by way of example, an automated patient management environment.  
         [0014]      FIG. 2  is a tree diagram showing, by way of example, a control hierarchy of medical devices for use in the patient management environment of  FIG. 1 .  
         [0015]      FIG. 3  is a data flow diagram showing hierarchical medical device control and feedback in the patient management environment of  FIG. 1 .  
         [0016]     FIGS.  4 A-C are Venn diagrams showing, by way of example, data sets as maintained in the patient management environment of  FIG. 1 .  
         [0017]      FIG. 5  is a graph showing the relationship between sampling frequency and sample size.  
         [0018]      FIG. 6  is a flow diagram showing a method for providing hierarchical medical device control for automated patient management for use on the server of  FIG. 3 .  
         [0019]      FIG. 7  is a flow diagram showing a method for providing hierarchical medical device control for automated patient management for use on a patient management device of  FIG. 3 .  
         [0020]      FIG. 8  is a flow diagram showing a method for providing hierarchical medical device control for automated patient management for use on a medical device of  FIG. 3 .  
         [0021]      FIG. 9  is a block diagram showing a system for providing hierarchical medical device control for automated patient management for use on the server of  FIG. 3 .  
         [0022]      FIG. 10  is a block diagram showing a system for providing hierarchical medical device control for automated patient management for use on a patient management device of  FIG. 3 .  
         [0023]      FIG. 11  is a block diagram showing a system for providing hierarchical medical device control for automated patient management for use on a medical device of  FIG. 3 . 
     
    
     DETAILED DESCRIPTION  
       [0000]     Automated Patient Management Environment  
         [0024]     Automated patient management encompasses a range of activities, including remote patient management and automatic diagnosis of patient health, such as described in commonly-assigned U.S. Pat. application Pub. No. US2004/0103001, published May 27, 2004, pending, the disclosure of which is incorporated by reference. Such activities can be performed proximal to a patient, such as in the patient&#39;s home or office, centrally through a centralized server, such from a hospital, clinic or physician&#39;s office, or through a remote workstation, such as a secure wireless mobile computing device.  FIG. 1  is a functional block diagram showing, by way of example, an automated patient management environment  10 . In one embodiment, a patient  14  is proximal to one or more patient monitoring or communications devices, which are interconnected remotely to a centralized server  13  over an internetwork  11 , such as the Internet, or through a public telephone exchange (not shown), such as a conventional or mobile telephone network. The patient monitoring or communications devices non-exclusively include a patient management device  12 , such as a repeater, personal computer  19 , including a secure wireless mobile computing device, telephone  20 , including a conventional or mobile telephone, and facsimile machine  21 . In a further embodiment, a programmer  22 , such as a programmer or programmer-recorder monitor, can be used by clinicians, such as physicians, nurses, or qualified medical specialists, to interrogate and program medical devices. Finally, the centralized server  13  is remotely interfaced to a patient care facility  25 , such as a clinic or hospital, to ensure access to medical response or patient care providers. Other patient monitoring or communications devices are possible. In addition, the internetwork  11  can provide both conventional wired and wireless interconnectivity. In one embodiment, the internetwork  11  is based on the Transmission Control Protocol/Internet Protocol (TCP/IP) network communication specification, although other types or combination of networking implementations are possible. Similarly, other network topologies and arrangements are possible.  
         [0025]     Each patient management device  12  is uniquely assigned to a patient under treatment  14  to provide a localized and network-accessible interface to one or more medical devices, which serve as patient data sources  15 - 18 , either through direct means, such as wired connectivity, or through indirect means, such as inductive coupled telemetry, optical telemetry, or selective radio frequency or wireless telemetry based on, for example, “strong” Bluetooth or IEEE 802.11 wireless fidelity “WiFi” and “WiMax” interfacing standards. Other configurations and combinations of patient data source interfacing are possible.  
         [0026]     Patient data includes physiological measures, which can be quantitative or qualitative, parametric data regarding the status and operational characteristics of the patient data source itself, and environmental parameters, such as the temperature, barometric pressures, or time of day. The patient data sources collect and forward the patient data either as a primary or supplemental function. Patient data sources  15 - 18  include, by way of example, medical devices that deliver or provide therapy to the patient  14 , sensors that sense physiological data in relation to the patient  14 , and measurement devices that measure environmental parameters occurring independent of the patient  14 . Other types of patient data are possible, such as third party data  26  received from external data sources, including repositories of empirical studies, public and private medical databases, patient registries, and the like. Additionally, current clinician-established guidelines associated with treatment can help to guide acceptable best practice treatment for patient care. Each patient data source can generate one or more types of patient data and can incorporate one or more components for delivering therapy, sensing physiological data, measuring environmental parameters, or a combination of functionality.  
         [0027]     In a further embodiment, data values can be entered by a patient  14  directly into a patient data source. For example, answers to health questions could be input into a measurement device that includes interactive user interfacing means, such as a keyboard and display or microphone and speaker. Such patient-provided data values could also be collected as patient information. Additionally, measurement devices are frequently incorporated into medical therapy devices and medical sensors. Medical therapy devices include implantable medical devices (IMDs)  15 , such as pacemakers, implantable cardiac defibrillators (ICDs), drug pumps, and neuro-stimulators, and external medical devices (EMDs)  16 , such as automatic external defibrillators (AEDs). Medical sensors include implantable sensors  17 , such as implantable heart and respiratory monitors and implantable diagnostic multi-sensor non-therapeutic devices, and external sensors  18 , such as 24-hour Holter arrhythmia monitors, ECG monitors, weight scales, glucose monitors, oxygen monitors, and blood pressure monitors. Other types of medical therapy, medical sensing, and measuring devices, both implantable and external, are possible.  
         [0028]     The patient management device  12  collects and temporarily stores patient data from the patient data sources  15 - 18  for periodic upload over the internetwork  11  to the server  13  and storage in a patient population database  24 . Each patient  14  can be remotely managed through hierarchical control exercised by the server  13  over the patient management devices  12  and patient data sources  15 - 18 , as further described below beginning with reference to  FIG. 2 . Briefly, a clinician defines a therapy goal for a patient based on a stored physiological assessment of a diagnosed disease state. The server  13  defines a control strategy for meeting a therapy goal and the control strategy is delegated to each of the devices through goals and sub-goals to form a closed loop control system. Control flows downward through the hierarchy, increasing in specificity with each decreasing level, and feedback flows upward, increasing in detail and temporal scope with each increasing level.  
         [0029]     Each patient data source  15 - 18  collects the quantitative physiological measures on a substantially continuous basis and also records the occurrence of events, such as therapy or irregular readings. In a still further embodiment, the patient management device  12 , personal computer  19 , telephone  20 , or facsimile machine  21  record or communicate qualitative quality of life (QOL) measures that reflect the subjective impression of physical well-being perceived by the patient  14  at a particular time. Other types of patient data collection, periodicity and storage are possible.  
         [0030]     In a further embodiment, the collected patient data can also be accessed and analyzed by one or more clients  23 , either locally-configured or remotely-interconnected over the intemetwork  11 . The clients  23  can be used, for example, by clinicians to securely access stored patient data assembled in the database  24  and to select and prioritize patients for health care provisioning, such as respectively described in commonly-assigned U.S. patent application, Ser. No. 11/121,593, filed May 3, 2005, pending, and U.S. patent application, Ser. No. 11/121,594, filed May 3, 2005, pending, the disclosures of which are incorporated by reference. Although described herein with reference to physicians or clinicians, the entire discussion applies equally to organizations, including hospitals, clinics, and laboratories, and other individuals or interests, such as researchers, scientists, universities, and governmental agencies, seeking access to the patient data.  
         [0031]     In a further embodiment, patient data is safeguarded against unauthorized disclosure to third parties, including during collection, assembly, evaluation, transmission, and storage, to protect patient privacy and comply with recently enacted medical information privacy laws, such as the Health Insurance Portability and Accountability Act (HIPAA) and the European Privacy Directive. At a minimum, patient health information that identifies a particular individual with health-and medical-related information is treated as protectable, although other types of sensitive information in addition to or in lieu of specific patient health information could also be protectable. Additionally, for purposes of utilizing information in the population database  24  or third party data  26 , comparison data can be de-identified, such that specific patient identification is not available.  
         [0032]     Preferably, the server  13  is a server-grade computing platform configured as a uni-, multi-or distributed processing system, and the clients  23  are general-purpose computing workstations, such as a personal desktop or notebook computer. In addition, the patient management device  12 , server  13  and clients  23  are programmable computing devices that respectively execute software programs and include components conventionally found in computing device, such as, for example, a central processing unit (CPU), memory, network interface, persistent storage, and various components for interconnecting these components.  
         [0000]     Medical Device Hierarchy  
         [0033]     A control strategy is a closed-loop combination of all actions taken by the various medical devices that affect the attainment of a therapy goal. A control strategy can involve a server  13 , one or more patient management devices  12 , and one or more medical devices  15 - 18 . By default, the specificity of control, as delegated through the control strategy, is exercised over the operations performed by the server  13 , patient management devices  12 , and medical devices  15 - 18  to increase with immediacy to the patient  14 . Conversely, the scope of feedback provided by these devices increases with distance from the patient  14 . These characteristics can be formed into a hierarchy of bi-directional control and feedback.  FIG. 2  is a tree diagram showing, by way of example, a control hierarchy  30  of medical devices for use in the patient management environment  10  of  FIG. 1 . The control hierarchy  30  is structured into four levels respectively corresponding to a server; one or more patient management devices; one or more medical devices that are each assigned to a patient management device; and sensors and effectors that respectively measure physiological data and deliver therapy.  
         [0034]     A server is at the top or root level  31  of the control hierarchy  30  and serves as the primary controller for the patient management environment  10 . From the prospective of the server, the successive levels  32 - 34  of the control hierarchy  30  constitute the physical plant over which control is exercised and from which feedback is received.  
         [0035]     The patient management devices form an intermediate level  32  of the control hierarchy  30  and interface to both the server and one or more medical devices. In one embodiment, each patient management device is uniquely identified to a single patient  14 . In a further environment, a patient management device can be shared by a plurality of patients  14 . Each patient management device operates as a controller over the medical devices assigned, which constitute the physical plant over which the patient management device exercises control and from which feedback is received. In addition, each patient management device sends feedback to the server and receives control in the form of sub-goals from the server.  
         [0036]     The medical devices form a penultimate level  33  of the control hierarchy  30  and can include sensors, effectors, or both, which are on the bottom or terminal level  34  of the control hierarchy  30 . Each medical device functions as a controller over the sensors and effectors, which, in combination with the patient  14 , constitute the physical plant over which control is exercised via the effectors and from which feedback is received from the sensors. In addition, each medical device sends feedback to the patient management device and receives control in the form of sub-goals from the patient management device.  
         [0037]     In a strict control hierarchy  30 , control is only exercised over and feedback is only received from the devices assigned to the next immediate level of the control hierarchy  30 . In a more relaxed and pragmatic control hierarchy  30 , control can flow down to and feedback can be received from the devices in any successive level of the control hierarchy  30 , with one exception. Each medical device is physically coupled to sensors and effectors and operates under an event response control strategy, which does not admit to cooperative external control. However, a server can still exercise control over and receive feedback directly from patient medical devices and medical devices.  
         [0038]     When executing as a closed loop control system, outside control and feedback reporting are not provided. However, direct control over the server, patient medical devices, and medical devices is possible and, for bootstrapping the server, necessary to specify initial therapy goals and implementing actions, including control parameters, environmental settings, and hierarchy assignments, such as further described below with reference to  FIG. 3 . Other levels or configurations and arrangements of tiered hierarchical control in addition to or lieu of a tree structure are also possible.  
         [0000]     Data Flow  
         [0039]     Generally, control flows downward in increasing levels of specificity and feedback flows upward in increasing levels of detail and temporal scope.  FIG. 3  is a data flow diagram showing hierarchical medical device control and feedback  40  in the patient management environment  10  of  FIG. 1 . The server  41  is operatively coupled to a one or more patient management devices  42 , which are each in turn operatively coupled to one or more medical devices  43 . Each medical device  43  includes one or more sensors  44 , one or more effectors  45 , or a combination of both sensors  44  and effectors  45  depending upon the type of medical device.  
         [0040]     The server  41  exercises patient-level control  56  over the patient management device  42  assigned and, in a further embodiment, device-level control  52  over medical devices  43 . Each patient management device  42  exercises device-level control  52  over the medical devices  43  assigned. As event/response control devices, each medical device  43  maintains exclusive control over the interfaced sensors  44  and effectors  45 . Each medical device  43  delivers therapy  48 , such as pacing stimuli, through the interfaced effectors  45  and receives physiological measures  46  from the interfaced sensors  44 . The received physiological measures  46  are transiently staged by the medical device  43  as limited state  47  before being uploaded to the assigned patient management device  42  and, in a further embodiment, the server  41 , as device-level feedback  50  that can be analyzed with local state  51 ,  55  against the current control strategy. Each patient management device  42  uploads patient-level feedback  54  to the server  41 , which can include physiological measures, parametric data, and environmental parameters as well as the results of local analyses and unprocessed device-level feedback  50 . In addition to analyzing patient-level feedback  54  and, in a further embodiment, device-level feedback  50 , the server  41  maintains access to the patient population database  24  and, in a further embodiment, third party data  26 , which can both be factored into the analyses performed by the server  41 . Other types of feedback and data access, exchange, and storage are possible.  
         [0041]     A control strategy is implemented through goals and sub-goals that are delegated to devices in order of increasing specificity relative to the level of control exercised over the patient  14 . Patient-level control  56 , for instance, delegates a control strategy specific to a particular patient  14  who is uniquely assigned to a patient management device  42 . Patient-level control  56  can affect one or more individual medical devices  43 . Similarly, device-level control  52  delegates a control strategy specific to a particular medical device  43  based on the medical device type and the indicated form of therapy.  
         [0042]     Direct control  49 ,  53 ,  57  can respectively be exercised over each medical device  43 , patient management device  42 , and the server  41 , as would be necessary, for example, to set up the initial control parameters and environment settings necessary for each device to join into a hierarchical control strategy. Direct control over a medical device  43  can be provided through a programmer  22  (shown in  FIG. 1 ) or patient management device  42 . Direct control over a patient management device  42  could be provided through a client  23  (also shown in  FIG. 1 ) or via a user interface of the patient management device  42 . Direct control over the server  41  could be provided through a client  23 .  
         [0043]     Conversely, the detail and temporal scope of feedback increases as the available resources for storing and processing feedback increase and as the number of individual sources of feedback grow. Medical devices  43 , as event/response control systems, maintain only limited state  47  in which to store temporarily physiological measures  47  received from interfaced sensors  44 . With limited processing and power budget resources, each medical device  47  is typically constrained to limit processing of the physiological measures  46  to the extent necessary to determine the applicability to therapy delivery to the patient  14 . Patient management devices  42  enjoy significantly more capable resources, including processing and storage, in which to store and analyze device-level feedback  50 , which can be evaluated against the control strategy and analyzed, for instance, for trends indicating a progression, regression, absence, onset, or status quo of a physiological condition, and changes to the control strategy exercised by the assigned medical devices  43  can be effected through device control  52 , which can include control parameters to reprogram assigned medical devices  43 . The server  41  enjoys processing and storage resources at least on par with the patient management devices  42  and, typically, has far more capable resources. However, the wider range of sources of feedback, including patient-level feedback  54  from a plurality of patient management devices  42  and, in a further embodiment, directly-received device-level feedback  50  from a plurality of medical devices  43 , introduce a richness of patient data at a population level that enables the server  41  to perform a wider range of comparative analyses across a spectrum of patient characteristics and health conditions, such as described in commonly-assigned U.S. patent application, entitled “System And Method For Providing Goal-Oriented Patient Management Based Upon Comparative Population Data Analysis,” Ser. No.______, filed on Jan. 19, 2006, pending, the disclosure of which is incorporated by reference. Other forms of analyses and processing are possible.  
         [0000]     Data Set Examples  
         [0044]     Each device maintains data sets that include feedback and control strategy data. FIGS.  4 A-C are Venn diagrams showing, by way of example, data sets  70  as maintained in the patient management environment  10  of  FIG. 1 . The composition of each data set reflects the capabilities and storage capacities of the device. For instance, the data sets maintained by each medical device  43  are the most constrained due to the limited processing and storage resources available, whereas the data sets maintained by each patient management device  42  and by the server  41  are less constrained in terms of both processing and storage resources. Referring first to  FIG. 4A , the data sets  70  maintained by medical devices  43  can include physiological measures or locally-generated data and analyses (“measures”)  71 , control parameters  72 , or a combination of measures and control parameters  73 , depending upon the type of medical device.  
         [0045]     Patient management devices  42  have greater processing capabilities and storage capacities than medical devices  43 . Referring next to  FIG. 4B , the data sets  74  maintained by patient management devices  42  can include measures recorded or generated by assigned medical devices  75 , control parameters of assigned medical devices  76 , or a combination of measures and control parameters  77 . The measures  75  are provided as device-level feedback  50 . In addition, the data sets  74  can also include physiological measures or data and analyses  78  that have respectively been locally measured or generated by the patient management devices  42 .  
         [0046]     Finally, the server  41  has a patient population-wide prospective, which potentially encompasses all of the individual data sets for assigned patient management device  42  and medical devices  43 . Referring to  FIG. 4C , the data set  79  maintained by the server  41  can include all of the medical device data sets and patient management device data sets. In addition, the data set  79  can also include data and analyses (not shown) that have been locally generated by the server  41 . Other forms, combinations, and compositions of data sets are possible.  
         [0000]     Sampling  
         [0047]     The detail and temporal scope of feedback grows as the number of independent sources and the rates of sampling applied at each hierarchy level increase.  FIG. 5  is a graph  80  showing the relationship between sampling frequency and sample size. The x-axis represents the sampling frequency  81  and the y-axis represents the sample size  82 .  
         [0048]     In a control system with unlimited sampling resources, including state, an unconstrained sample size will continue to increase as a function  83  of the sampling frequency. However, due to the inherent limits in sampling resources in discrete devices, particularly with respect to medical devices  43  and the limited state  47  available for storing samples, the sample size instead decreases as a function  84  of the sampling frequency with the smallest samples being collected with the highest frequency by the medical devices  43  and largest samples being collected by the server  41  and patient management devices  42  with the lowest frequencies. Thus, medical devices  43  generally employ sampling rates in the millisecond range, while dedicated patient management devices  42  can sample on an hourly or daily basis and the server  41  can sample on a daily, weekly or monthly basis. The differences in sampling frequency allow each respective device to accumulate additional patient data samples and, where resources permit, to perform comparative analyses on the patient data to summarize and identify trends. Other sampling frequency and samples size relationships between the medical devices are possible.  
         [0000]     Server Method  
         [0049]     The operations performed by the server  41 , patient management devices  42 , and medical devices  43  are dependent upon the applicable sources and destinations of feedback and control strategy. Except when provided direct control  57  from external sources, such as a clinician providing instructions through a client  23 , the server  41  functions as an autonomous closed loop controller that exercises control over the patient management devices  42  and medical devices  43  assigned to the control hierarchy.  FIG. 6  is a flow diagram showing a method  90  for providing hierarchical medical device control for automated patient management for use on the server  41  of  FIG. 3 . The method  90  is generally performed on the server  41 , but could also be performed on a patient management device  42  or client  23  with sufficient resources and interconnections.  
         [0050]     Initially, a control strategy is defined (block  91 ), which can be provided through direct control  57  or by analysis of the patient population database  24  or other sources, such as described in commonly-assigned U.S. patent application, entitled “System And Method For Providing Goal-Oriented Patient Management Based Upon Comparative Population Data Analysis,” Ser. No.______, filed on Jan. 19, 2006, pending, the disclosure of which is incorporated by reference. The control strategy can be decomposed into sub-goals that can be delegated to patient management devices  42  as patient-level control  56  and, in a further embodiment, as device-level control  52  to medical devices  43  (block  92 ). A closed control loop is then initialized (block  93 ) by verifying, as necessary, connectivity to each assigned patient management device  42  and medical device  43  and confirming satisfactory operational statuses. The continuous closed control loop (blocks  94 - 99 ) is then performed until the processing infrastructure, for instance, the server  41 , terminates execution.  
         [0051]     During each cycle (block  94 ), patient-level feedback  54  is received and integrated into the state  55  maintained by the server  41 (block  95 ). The patient-level feedback  54  and state  55  are analyzed against the current control strategy, such as through data mining (block  96 ). In one embodiment, the state is represented as a matrix dimensioned temporally as a set of vectors for the tracked patient data, including physiological measures, control parameters, and environmental parameters. Other types of tracked patient data and forms of internal state representation are also possible. If based on the analysis, the control strategy requires adjustment (block  97 ), revised patient-level control  56  and, in a further embodiment, device-level control  52 , are sent to the appropriate device (block  98 ). Closed control loop processing (block  99 ) is performed continually, but can be subject to interruption or modification by external sources, such as direct control  57 .  
         [0000]     Patient Management Device Method  
         [0052]     Except when provided direct control  53 , each patient management device  42  also functions as an autonomous closed loop controller that exercises control over the medical devices  43  assigned to the control hierarchy, subject to patient-level control  56  delegated by the server  41 .  FIG. 7  is a flow diagram showing a method  110  for providing hierarchical medical device control for automated patient management for use on a patient management device  42  of  FIG. 3 . The method  110  is preferably performed by a patient management device  42  but, in a further embodiment, could also be performed by a server  41  or client  23 .  
         [0053]     Each patient management device  42  operates in two logical roles. First, as part of the physical plant of the control system implemented by the server  41 , each patient management device  42  receives patient-level control  56 , which defines the initial control strategy to be executed (block  111 ). Second, as a controller to the medical devices  43  assigned, each patient management device  42  delegates sub-goals (block  112 ), which, in a further embodiment, could also be sent to other patient management devices  42  or the server  41 . Other patient management device functions are possible. A closed control loop is then initialized (block  113 ) by verifying, as necessary, connectivity to each assigned medical device  43  and confirming satisfactory operational statuses. The continuous closed control loop (blocks  114 - 124 ) is then performed until the processing infrastructure, for instance, the patient management device  42 , terminates execution.  
         [0054]     During each cycle (block  114 ), three threads of control are performed to receive patient-level control  56  (blocks  115 - 117 ), receive device-level feedback  50  and send device control  52  (blocks  118 - 121 ), and send patient-level feedback  54  (blocks  122 - 123 ). In the patient-level control thread, changes to the control strategy that are received as patient-level control  56  from the server  41  are monitored (block  115 ). If the control strategy has changed (block  116 ), the control parameters for the patient management device  42 , and if applicable, for one or more of the attached medical devices  43 , are revised (block  117 ). Device-level control  52  to the appropriate assigned medical devices  43  is also sent. In the medical device control thread, patient data is received as device-level feedback  50  from each assigned medical device  43  and is integrated into the state  51  for the patient management device  42  (block  118 ). The device-level feedback  50  and state  51  are analyzed against the current control strategy (block  119 ) and, if the current control strategy requires adjustment (block  120 ), device-level control  52  is sent to the appropriate assigned medical devices  43  (block  121 ). Finally, in the patient-level feedback thread, device-level feedback  50  and state  51  are processed (block  122 ) and provided as patient-level feedback  54  to the server  41  (block  123 ). Processing can include summarizing and extrapolating the patient data over those devices that constitute the physical plant of the patient management device  42 . Other types of processing are possible. Closed control loop processing (block  124 ) is performed continually, but can be subject to interruption or modification by external sources, such as direct control  53 .  
         [0000]     Medical Device Method  
         [0055]     Except when provided direct control  49 , each medical device  43  also functions as an autonomous event/response controller that receives physiological measures  46  from sensors  44  and delivers therapy  48  through effectors  45 , subject to patient-level control  56  delegated by an associated patient management device  42  and, in a further embodiment, the server  41 .  FIG. 8  is a flow diagram showing a method  130  for providing hierarchical medical device control for automated patient management for use on a medical device  43  of  FIG. 3 . The method  130  is performed by a medical device  43 .  
         [0056]     Each medical device  43  operates in two logical roles. First, as part of the physical plant of the control system implemented by the associated patient management device  42  and, in a further embodiment, the server  41 , each medical device  43  receives device-level control  52 , which defines the initial control strategy to be executed (block  131 ). Second, as an event/response controller, each medical device  43  delivers therapy, such as pacing stimuli, and receives physiological measures. Other medical device functions are possible. An event/response control loop is then initialized (block  132 ) by confirming satisfactory operational statuses of the sensors  44  and effectors  45 . The event/response control loop (blocks  133 - 143 ) is then performed until the processing infrastructure, for instance, the medical device  43 , terminates execution.  
         [0057]     During each cycle (block  133 ), three threads of control are performed to receive device-level control  52  (blocks  134 - 136 ), control sensors  44  and effectors  45  (blocks  137 - 140 ), and send device-level feedback  50  (blocks  141 - 142 ). In the device-level control thread, changes to the control strategy that are received as device-level control  52  from the assigned patient management device  42  and, in a further embodiment, the server  41  are monitored (block  134 ). If the control strategy has changed (block  135 ), the control parameters for the medical device  43  are revised (block  136 ), which could affect the event occurrence and response characteristics of the medical device  43 . In the sensors  44  and effectors  45 , control thread, physiological measures  46  are received from each sensor  44  and are integrated into the limited state  47  for the medical device  43  (block  137 ). The physiological measures  46  and limited state  47  are analyzed against the current control strategy (block  138 ) and, if the current control strategy requires adjustment (block  139 ), revised control is applied to the interfaced sensors  44  and effectors  45  (block  140 ). Finally, in the device-level feedback thread, physiological measures  46  and the limited state  47  are processed (block  141 ) and provided as device-level feedback  50  to the associated patient management device  43  and, in a further embodiment, to the server  41  (block  142 ). Processing can include averaging or summarizing the physiological measures  46 . Other types of processing are possible. Closed control loop processing (block  143 ) is performed continually, but can be subject to interruption or modification by external sources, such as direct control  49 .  
         [0000]     Server Structure  
         [0058]     Generally, the server is responsible for exercising control over the patient management devices and medical devices assigned.  FIG. 9  is a block diagram showing a system  150  for providing hierarchical medical device control for automated patient management for use on the server of  FIG. 3 . The server  151  implements the system  150  and executes a sequence of programmed process steps, such as described above with reference to  FIG. 6 , implemented, for instance, on a programmed digital computer system.  
         [0059]     The server  151  includes a controller  152 , input processor  153 , and output processor  154 . The server  151  also maintains an interface to the patient population database  155 . The patient population database  155  is used to maintain patient data  156 , which can include patient characteristics, wellness, treatment plans, regimens, and other types of information. The patient information  156  is maintained for those patients belonging to the population of patients managed by the server  151  as well as for other patients not strictly within the immediate patient population, such as retrieved from third party data sources  26 .  
         [0060]     The controller  152  processes feedback  158  that can include patient-level feedback  54  and, in a further embodiment, device-level feedback  50 , and the patient data  156 , which constitutes part of the state  55  maintained by the server  151 . The state is analyzed against the current control strategy  157  to determine if changes to the current control strategy  157  are needed. Other types of analyses are possible. The feedback  158  and control strategy  157  are received by the input processor  153 , which integrates the feedback  158  into the patient data  156  stored in the patient population database  155  and provides the control strategy  157  to the controller  152 , which delegates programming  159  as sub-goals to assigned patient management devices  42 , and, in a further embodiment, medical devices  43 . The output processor  154  sends programming  159  and can also provide feedback  160  to external sources, such as clients  23  (shown in  FIG. 1 ) or displays associated with the patient management device for further display and analysis. Other components and functionality are possible.  
         [0000]     Patient Management Device Structure  
         [0061]     Generally, each patient management device is responsible for exercising control over the medical devices assigned.  FIG. 10  is a block diagram showing a system  170  for providing hierarchical medical device control for automated patient management for use on a patient management device of  FIG. 3 . The patient management device  171  implements the system  170  and executes a sequence of programmed process steps, such as described above with reference to  FIG. 7 , implementing, for instance, on a programmed digital computer system.  
         [0062]     The patient management device  171  includes a controller  172 , input processor  173 , and output processor  174 . Medical device data  175  is maintained for the assigned medical devices  43 . The controller  172  processes feedback  177  that can include device-level feedback  50 , which constitutes part of the state  51  maintained by the patient management device  42 . The state is analyzed against the current control strategy  176  to determine if changes to the current control strategy  176  are needed. Other types of analyses are possible; The feedback  177  and control strategy  176  are received by the input processor  173 , which integrates the feedback  177  into the medical device data  175  and provides the control strategy  176  to the controller  172 , which delegates programming  178  as control parameters to assigned medical devices  43 . The output processor  174  sends programming  178  and can also provide feedback  179  to the server  41  and external sources, such as clients  23  (shown in  FIG. 1 ) for further display and analysis. Other components and functionality are possible.  
         [0000]     Medical Device Structure  
         [0063]     Generally, each medical device is responsible for monitoring physiological measures and providing therapy to the patient  14 .  FIG. 11  is a block diagram showing a system  190  for providing hierarchical medical device control for automated patient management for use on a medical device of  FIG. 3 . The medical device  191  implements the system  190  and executes a sequence of programmed process steps, such as described above with reference to  FIG. 8 , implemented, for instance, on an embedded microprocessor-based system.  
         [0064]     The medical device  191  includes a controller  192 , input processor  193 , and output processor  194 . Staged measures  195  are maintained for the sensors  44 . The controller  192  processes physiological measures  197 , which constitute part of the limited state  47  maintained by each medical device  190 . The limited state  47  is analyzed against the current control strategy  196  to determine if changes to the programming are required. Other types of analyses are possible. The physiological measures  197  and control strategy  196  are received by the input processor  193 , which integrates the physiological measures  197  into the staged measures  195  and provides the control strategy  196  to the controller  192  as programming that is implemented to change the event occurrence and response control performed by the medical device  190 . The output processor  194  delivers therapy  198  to the patient  14  and can also provide feedback  199  to the associated patient management device  42  and, in a further embodiment, the server  41 , plus external sources, such as clients  23  (shown in  FIG. 1 ) for further display and analysis. Other components and functionality are possible.  
         [0065]     While the invention has been particularly shown and described as referenced to the embodiments thereof, those skilled in the art will understand that the foregoing and other changes in form and detail may be made therein without departing from the spirit and scope of the invention.