The present system relates generally to the art of glucose monitoring, and more particularly to hypo- and hyper-glycemic risk assessment.
Bio-behavioral feedback and its critical importance for the control of diabetes is a complex of disorders, characterized by a common final element of hyperglycemia, that arise from, and are determined in their progress by, mechanisms acting at all levels of bio-system organization—from molecular, through hormonal, to human behavior. Intensive treatment with insulin and with oral medication to maintain nearly normal levels of glycemia markedly reduces chronic complications in both Type 1 (34,40) and Type 2 diabetes (T1DM, T2DM, 42), but may risk potentially life-threatening severe hypoglycemia (SH). State-of-the-art but imperfect insulin replacement may reduce warning symptoms and hormonal defenses against hypoglycemia, resulting in cognitive dysfunction, stupor, coma, or sudden death (16,17,31,39). In addition, recent studies suggest that hypoglycemia may trigger increased insulin sensitivity (18,32). Therefore, hypoglycemia has been identified as the primary barrier to optimal diabetes management (9,11). People with T1DM and T2DM face a life-long behaviorally controlled optimization problem to reduce hyperglycemic excursions and maintain strict glycemic control, without increasing their risk for hypoglycemia.
A key to this, as well as many, optimization problems is providing and appropriately utilizing available feedback for the system's status and dynamics. Approached from a systems biology point of view, the task of optimization of T1DM requires study of feedback loops at several bio-system levels: (1) external feedback to the patient altering human behavior; (ii) insulin-glucose interaction, and (iii) hormonal feedback occurring with recurrent hypoglycemia from one hypoglycemic episode to the next, reflected by hypoglycemia-associated autonomic failure (HAAF, 10).
Feedback loop 1 (
HbA1c: This classic marker of average glycemic status (1) has been linked to long-term complications of diabetes, and confirmed as the gold standard for both T1DM and T2DM (36). However, HbA1c has repeatedly been proven to be an ineffective assessment of patients' extreme glucose fluctuations. The DCCT concluded that only about 8% of SH episodes could be predicted from known variables, including HbA1c (39); later this prediction was improved to 18% by a structural equation model using history of SH, awareness, and autonomic symptom score (15). In our studies HbA1c has never been significantly associated with SH (6,23,27).
SMBG: Contemporary home BG meters offer convenient means for frequent and accurate BG determinations through SMBG (3,7,41). Most meters are capable of storing hundreds of SMBG readings, together with the date and time of each reading, and have interfaces to download these readings into a PC. The meters are usually accompanied by software that has capabilities for basic data analyses (e.g. calculation of mean BG, estimates of the average BG over the previous two weeks, percentages in target, hypoglycemic and hyperglycemic zones, etc.), log of the data, and graphical representation (e.g. histograms, pie charts). However, while these devices provide information about current status of BG at a point in time, none of them provide assessment of patients' overall glycemic control, BG patterns and trends, or self-treatment effectiveness when a BG result is given. In a series of studies we have shown that specific analysis of SMBG data, the low BG Index (LBGI), could capture long-term trends towards increased risk for hypoglycemia (23,24,29) and could identify 24-hour periods of increased risk for hypoglycemia (20). These analyses were based on recognition of a specific asymmetry of the BG measurement scale and on a nonlinear transformation correcting this asymmetry (22,25). Since our first announcement (6), we refined and further validated our methods and presented a structured theory of Risk Analysis of BG Data (28). This theory became a basis for our algorithms using SMBG to comprehensively evaluate glycemic control in T1DM (21, 27).
Monitoring and Assessment of Behavior: In order to formally describe the behavioral self-treatment process we created the Stochastic Model of Self-Regulation Behavior, which gives a mathematical description to the feedback pattern internal condition—symptom perception/awareness—appraisal—self-regulation decision (26,
Utility of Behavioral Interventions: Several studies have documented that the avoidance of low BG events (<70 mg/dl) for a few weeks can improve symptom perception and reverse hypoglycemia unawareness (8,12,13,14). While such an intervention has promise for reducing SH risk, it needs close patient monitoring to ensure that metabolic control is not jeopardized (2). We have previously developed BGAT, a well-documented, effective, psycho-behavioral intervention for people with T1DM. Its many positive effects include improvement in BG detection, BG profiles, psychosocial status, know ledge, decision-making, and reduced life-threatening events such as severe hypo- and hyperglycemia (4,5). Additionally, we have shown that BGAT improves low BG detection in both patients with intact hypoglycemic symptoms and those with reduced awareness. Researchers at the Joslin Clinic found that BGAT preserved counterregulation integrity in patients undergoing intensive insulin therapy (19).
An aspect of various embodiments of the present invention focuses on, but not limited thereto, Feedback loop #1 (FIG. 1)—temporal patterns of glycemia and behavior. A premise is that to enable behavioral changes via algorithmic recognition of idiosyncratic temporal patterns of glycemia and self-testing. In particular, patterns of hyperglycemia and hypoglycemia, increased glucose variability, and ineffective self-monitoring are recognized, and messages are conveyed back to the person in real time.
As postulated by the stochastic model of self-treatment behavior (
An aspect of various embodiments of the present invention consists of, but not limited thereto, four methods and algorithms for identifying patterns of: (i) hyperglycemia; (ii) hypoglycemia, (iii) increased glucose variability, and (iv) ineffective self-testing. The methods use routine SMBG data collected over a period of 2-6 weeks. SMBG is defined as episodic non-automated determination (typically 2 or more times per day) of blood glucose obtained in a diabetic patients' natural environment. A user, subject or patient may monitor oneself or rely on the assistance of others, e.g. a layperson, acquaintance, clinician, other medical professional, etc.
Various embodiments of the present invention may pertain directly to, among other things, the following:
One aspect of the invention includes a system, method, and computer program product for identifying patterns of hyperglycemia, defined as glucose averages within certain periods of time that exceed certain high glucose thresholds.
Another aspect of the invention includes a system, method, and computer program product for identifying patterns of hypoglycemia, defined as glucose averages within certain periods of time that exceed certain low glucose thresholds.
Another aspect of the invention includes a system, method, system, and computer program for identifying patterns of increased glucose variability, defined as certain periods of time in which the Average Daily Risk Range (ADRR), Standard Deviation, or other measure of blood glucose variability exceed certain thresholds. The ADRR is described in detail in a previously filed International Patent Application Serial No. PCT/US2007/000370, filed Jan. 5, 2007, entitled “Method, System and Computer Program Product for Evaluation of Blood Glucose Variability in Diabetes from Self-Monitoring Data” and see recent publication (30).
A fourth aspect of the invention includes a system, method, system, and computer program for identifying patterns of ineffective self-testing. Similar patterns have been described in a previous patent application (See PCT International Application No. PCT/US2003/025053, filed on Aug. 8, 2003) as a system of sample selection criteria for the evaluation of HbA1c from SMBG data.
The four pattern recognition methods use both population thresholds and individual thresholds adjusted for the glycemic status of the person. These four aspects of the invention can be integrated together to provide information about the timing during the day of risk for hyperglycemia, risk of hypoglycemia, risk of increased glucose variability, and ineffective testing of an individual with diabetes. Such information can be presented in addition to the information obtained and displayed by previously disclosed methods evaluating HbA1c, long-term and imminent risk for hypoglycemia, and overall glucose variability or other methods of evaluating patient status.
An aspect of an embodiment of the present invention provides a method for identifying and/or predicting patterns of hyperglycemia of a user. The method may compromise: acquiring plurality of SMBG data points; classifying said SMBG data points within periods of time with predetermined durations; evaluating glucose values in each period of time; and indicating risk of hyperglycemia for a subsequent period of time based on said evaluation.
An aspect of an embodiment of the present invention provides a system for identifying and/or predicting patterns of hyperglycemia of a user, wherein the system comprises an acquisition module acquiring a plurality of blood glucose data points and a processor. The processor may be programmed to: classify said SMBG data points within periods of time with predetermined durations; evaluate glucose values in each period of time; and indicate risk of hyperglycemia for a subsequent period of time based on said evaluation.
An aspect of an embodiment of the present invention provides a computer program product comprising a computer useable medium having computer program logic for enabling at least one processor in a computer system to identify and/or predict patterns of hyperglycemia of a user. The computer program logic may comprise: acquiring plurality of SMBG data points; classifying said SMBG data points within periods of time with predetermined durations; evaluating glucose values in each period of time; and indicating risk of hyperglycemia for a subsequent period of time based on said evaluation.
An aspect of an embodiment of the present invention provides a method for identifying and/or predicting patterns of hypoglycemia of a user. The method may compromise: acquiring plurality of SMBG data points; classifying said SMBG data points within periods of time with predetermined durations; evaluating glucose values in each period of time; and indicating risk of hypoglycemia for a subsequent period of time based on said evaluation.
An aspect of an embodiment of the present invention provides a system for identifying and/or predicting patterns of hypoglycemia of a user, wherein the system comprises an acquisition module acquiring a plurality of blood glucose data points and a processor. The processor may be programmed to: classify said SMBG data points within periods of time with predetermined durations; evaluate glucose values in each period of time; and indicate risk of hypoglycemia for a subsequent period of time based on said evaluation.
An aspect of an embodiment of the present invention provides a computer program product comprising a computer useable medium having computer program logic for enabling at least one processor in a computer system to identify and/or predict patterns of hypoglycemia of a user. The computer program logic may comprise: acquiring plurality of SMBG data points; classifying said SMBG data points within periods of time with predetermined durations; evaluating glucose values in each period of time; and indicating risk of hypoglycemia for a subsequent period of time based on said evaluation.
An aspect of an embodiment of the present invention provides a method for identifying and/or predicting patterns of high glucose variability of a user. The method may compromise: acquiring plurality of SMBG data points; classifying said SMBG data points within periods of time with predetermined durations; evaluating blood glucose variability in each said period of time; and indicating risk of higher variability for a subsequent period of time based on said evaluation.
An aspect of an embodiment of the present invention provides a system for identifying and/or predicting patterns of high glucose variability of a user, wherein the system comprises an acquisition module acquiring a plurality of blood glucose data points and a processor. The processor may be programmed to: classifying said SMBG data points within periods of time with predetermined durations; evaluating blood glucose variability in each said period of time; and indicating risk of higher variability for a subsequent period of time based on said evaluation.
An aspect of an embodiment of the present invention provides a computer program product comprising a computer useable medium having computer program logic for enabling at least one processor in a computer system to identify and/or predict patterns of high glucose variability of a user. The computer program logic may comprise: acquiring plurality of SMBG data points; classifying said SMBG data points within periods of time with predetermined durations; evaluating blood glucose variability in each said period of time; and indicating risk of higher variability for a subsequent period of time based on said evaluation.
An aspect of an embodiment of the present invention provides a method for identifying and/or predicting patterns of ineffective testing of a user. The method may compromise: acquiring plurality of SMBG data points; classifying said SMBG data points within periods of time with predetermined durations; calculating the percentage of SMBG readings in each said period of time; comparing percentage against preset thresholds; and indicating ineffective testing for said period of time.
An aspect of an embodiment of the present invention provides a system for identifying and/or predicting patterns of ineffective testing of a user, wherein the system comprises an acquisition module acquiring a plurality of blood glucose data points and a processor. The processor may be programmed to: classify said SMBG data points within periods of time with predetermined durations; calculate the percentage of SMBG readings in each said period of time; compare percentage against preset thresholds; and indicate ineffective testing for said period of time.
An aspect of an embodiment of the present invention provides a computer program product comprising a computer useable medium having computer program logic for enabling at least one processor in a computer system to identify and/or predict patterns of ineffective testing of a user. The computer program logic may comprise: acquiring plurality of SMBG data points; classifying said SMBG data points within periods of time with predetermined durations; calculating the percentage of SMBG readings in each said period of time; comparing percentage against preset thresholds; and indicating ineffective testing for said period of time.
These and other advantages and features of the invention disclosed herein, will be made more apparent from the description, drawings and claims that follow.
The accompanying drawings, which are incorporated into and form a part of the instant specification, illustrate several aspects and embodiments of the present invention and, together with the description herein, and serve to explain the principles of the invention. The drawings are provided only for the purpose of illustrating select embodiments of the invention and are not to be construed as limiting the invention
An aspect of various embodiments of this invention is, but not limited thereto, that providing real-time information to the patient about upcoming periods of possible hyperglycemia, possible hypoglycemia, increased glucose variability, or insufficient or excessive testing, will prompt appropriate treatment reaction and will thereby lead to better diabetes control.
At each SMBG measurement and prior to the presentation of SMBG result the device evaluates historical patterns of glycemia and, based on this evaluation, issues warnings for the next time period. These warning include high risk for hyperglycemia or hypoglycemia, increased glucose variability, insufficient or excessive testing (
The systems, methods and algorithms enabling the messaging system are the subject of this invention disclosure. The theoretical background has been established by our theory of risk analysis of BG data (27, 28, 30) and follows previously developed and disclosed technology. All methods and algorithms have been first developed using general statistical assumptions for the deviation of glucose levels or testing patterns within a certain time period from the grand glucose mean or optimal pattern of a person. Then, the resulting algorithms were applied to a large data set (N=335 subjects) to validate the algorithms and to determine ranges for the algorithm parameters. Table 1 presents demographic characteristics of the participants in this data set:
The predetermined duration of the next time period covered by the warning message could be anywhere between 2 and 8 hours, preferably 6 hours. A day, i.e. a twenty-four hour period, may be divided into time bins with predetermined durations. For simplicity of the description, throughout this disclosure we will assume time periods with a predetermined duration of 4-hour time periods, with an 8-hour time period during the night.
The next time period covered by the warning message can begin at any time, after any SMBG reading. For simplicity of the description, throughout this disclosure we assume that an SMBG reading is taken at 11 PM, which initializes the next time period of a predetermined duration, e.g. 11 PM-7 AM.
An aspect of the present invention method includes providing indications of the risk of hyperglycemia, risk of hypoglycemia, risk of high glucose variability, and ineffective testing of a user for a next period of time, i.e. a subsequent period of time, based on the evaluation of glucose values in each period of time. The indication of the risks or ineffective testing may occur after the completion of the following steps: the acquisition of plurality of SMBG data points, the classification of SMBG data points within periods of time with predetermined durations, and the evaluation of glucose values in each period of time. The indications may be in the form of messages that are issued to the user indicating risk or ineffective testing immediately prior to the next period of time. Indications may occur during, but are not limited to, the following times: immediately prior to the next period of time, within 24 hours of acquisition of a plurality of SMBG data points, within 12 hours of acquisition of plurality of SMBG data points, within 6 hours of acquisition of a plurality of SMBG data points, near contemporaneously to the latest SMBG testing, and occurring in real time as well.
The number of weeks of SMBG readings may be from about 2 weeks or over 6 weeks, but is preferably around 2 to 6 weeks, specifically about 4 weeks. Preferably, there are five readings per time period. The total number of SMBG readings may be from at least 30 readings, but preferably 60.
The algorithms identifying patterns of increased risk for hyperglycemia and hypoglycemia work through several sequential steps described in detail below. The idea is that a 24-hour daily SMBG profile of a person is split into fixed periods of time with a predetermined duration, beginning at the time of a SMBG reading, or at another predetermined time. Then, based on historical SMBG data, the average glucose in each period of time is evaluated for deviations towards hyperglycemia or hypoglycemia. These deviations are assessed at two levels for:
where N=N1+ . . . +NM is the total number of SMBG readings;
where Yk is the average of the means in the 4 time bins other than k and SD1 is an estimate of the SD of Xk−Yk. For example, for k=2 Y2=¼(X1+X3+X4+X5)
Given the null hypothesis that the mean in time bin k is not higher than the means in the other time bins, the statistic tk will have a close to t-distribution, which for N>30 can be approximated by a central normal distribution. In the validation data set the average absolute error of this approximation was 0.0009 (SD=0.001), thus the normal approximation is acceptable for the practical implementation of the algorithms. (NOTE: computing directly a t-distribution is quite difficult, which is the reason for the recommended normal approximation). The normal approximation of the probability that tk>0 can be computed as P (tk>0)=Φ(tk), where Φ(tk) is the distribution function of a central normal distribution (with mean zero and SD=1).
where
Thresholds of the Algorithms: The specific threshold values αi and βI (i=1,2) used by the algorithms should be determined by the manufacturer of the device using the algorithms, the clinician managing the patient using the algorithms, or the user, and should be based on the acceptability of the frequency of messages vs. utility of the messages. Using the database presented in the beginning of this section, we have compiled Table 2, which presents the frequency of the messages issued by the algorithm for hyperglycemia and Table 3, which presents the frequency of the messages issued by the algorithm for hypoglycemia, given various thresholds. At least 60 SMBG readings over 30 days and at least 5 readings per time bin were required for a subject to enter this computation.
The percentages in Tables 2 and 3 were computed as follows: For each subject and for each time bin we computed whether a message would be “issued.” If at least one message was “issued” for a subject, this subject was counted as 1 toward the frequency count in the tables.
The logic of the algorithm identifying patterns of increased glucose variability is similar to the logic of the algorithm identifying patterns of hyperglycemia. Instead of average BG, however, the test includes a measure of variability in each time bin. For example, such a measure could be the standard deviation (SD) of BG, or the risk standard deviation (RSD) of these values converted into risk space (28). In this implementation, we use the RSD because this measure is equally sensitive to hypoglycemic and hyperglycemic glucose variability.
The overall variability of a person is computed using the ADRR (average daily risk range), but can be also computed using the overall standard deviation of SMBG readings, M-value (37), MAGE (38), Lability Index (35), or any other accepted measure of variability (see Appendix A, 30, for a comprehensive list of possibilities). The standard deviation of SMBG readings would make the variability profile more sensitive to hyperglycemic excursions and less sensitive to hypoglycemia. In this implementation, we use the ADRR because this measure of variability has been shown to be superior in terms of its sensitivity to, and predictive ability of extreme glycemic excursions, and because it has clearly identified population thresholds (Appendix A, 30).
As in the previous section, it is assumed that an SMBG reading is taken at 11 PM and the subsequent 24-hour time period is split into time bins with a predetermined duration. Then, based on historical SMBG data, the glucose readings in each time bin are evaluated for deviations towards higher variability. These deviations are assessed for exceeding idiosyncratic threshold determined via analysis of the glycemic patterns of each individual. In addition, the overall ADRR of a person is classified with respect to population parameters. The combination of idiosyncratic deviations and overall ADRR is used to declare time period as high risk for increased variability. The judgment of each of the conditions is governed by two parameters:
Compute rl(BG)=r(BG) if f(BG)<0 and 0 otherwise;
Compute rh(BG)=r(BG) if f(BG)>0 and 0 otherwise.
Where n1, n2, . . . , nM≦3 and the number of days of observation M is between 14 and 42;
LR
i=max (rl(x1i), rl(x2i), . . . , rl(xni)) and
HR
i=max (rh(x1i), rh(x2i), . . . , rh(xni)) for day # i; i=1,2, . . . M.
The Average Daily Risk Range is then defined as:
Thresholds of the Algorithm: The specific threshold values α and β used by the algorithm should be determined by the manufacturer of the device using the algorithms based on the acceptability of the frequency of messages vs. utility of the messages. Using the database described above we have compiled Table 4, which presents the frequency of the messages issued by the algorithm, given various thresholds. At least 60 SMBG readings over 30 days and at least 5 readings per time bin were required for a subject to enter this computation.
Illustrative Example:
Similarly to the previously described algorithms, we assume that an SMBG reading is taken at 11 PM and then the algorithm identifying ineffective testing patterns splits the day into five time bins: 1˜[11 PM-7 AM); 2˜[7-11 AM); 3˜[11 AM-3 PM); 4˜[3-7 PM), and 5˜[7-11 PM)). Then, the algorithm computes the percentage of SMBG readings contained in each time bin.
If a time bin is found contains less than α %, or more than β % of a person's SMBG readings, then this time bin will be identified as a period of insufficient, or excessive testing, respectively. The parameters α % and β % can be set at any reasonable values, e.g. α %=5% and β %=50%. If one or both of these thresholds is exceeded, a message would be issued as presented in
Illustrative Example:
In the database used for validation of these methods, there were no examples of excessive sampling within a time bin for β %=50%. The highest testing frequency of all subjects across all time bins was 48.4% in the morning time bin (7-11 AM).
The method of the invention may be implemented using hardware, software or a combination thereof and may be implemented in one or more computer systems or other processing systems, such as a personal digital assistance (PDAs), or directly in blood glucose self-monitoring devices (e.g. SMBG memory meters) equipped with adequate memory and processing capabilities. In an example embodiment, the invention may be implemented in software running on a general purpose computer 900 as illustrated in
Computer system 900 may also include a main memory 908, preferably random access memory (RAM), and may also include a secondary memory 910. The secondary memory 910 may include, for example, a hard disk drive 912 and/or a removable storage drive 914, representing a floppy disk drive, a magnetic tape drive, an optical disk drive, a flash memory, etc. The removable storage drive 914 reads from and/or writes to a removable storage unit 918 in a well known manner. Removable storage unit 918, represents a floppy disk, magnetic tape, optical disc, etc. which is read by and written to by removable storage drive 914. As will be appreciated, the removable storage unit 918 may include a computer usable storage medium having stored therein computer software and/or data.
In alternative embodiments, secondary memory 910 may include other means for allowing computer programs or other instructions to be loaded into computer system 900. Such means may include, for example, a removable storage unit 922 and an interface 920. Examples of such removable storage units/interfaces include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as a ROM, PROM, EPROM or EEPROM) and associated socket, and other removable storage units 922 and interfaces 920 which allow software and data to be transferred from the removable storage unit 922 to computer system 900.
Computer system 900 may also include a communications interface 924. Communications interface 924 allows software and data to be transferred between computer system 900 and external devices. Examples of communications interface 924 may include a modem, a network interface (such as an Ethernet card), a communications port (e.g., serial or parallel, etc.), a PCMCIA slot and card, etc. Software and data transferred via communications interface 924 may be in the form of signals 928 which may be electronic, electromagnetic, optical or other signals capable of being received by communications interface 924. Signals 928 may be provided to communications interface 924 via a communications path (i.e., channel) 926. Channel 926 carries signals 928 and may be implemented using wire or cable, fiber optics, a phone line, a cellular phone link, an RF link, an infrared link, and other communications channels.
In this document, the terms “computer program medium” and “computer usable medium” are used to generally refer to media such as removable storage drive 914, a hard disk installed in hard disk drive 912, and signals 928. These computer program products are means for providing software to computer systems 900. The invention includes such computer program products.
Computer programs (also called computer control logic) may be stored in main memory 908 and/or secondary memory 910. Computer programs may also be received via communications interface 924. Such computer programs, when executed, enable computer system 900 to perform the features of the present invention as discussed herein. In particular, the computer programs, when executed, enable processor 904 to perform the functions of the present invention. Accordingly, such computer programs represent controllers of computer system 900.
In an embodiment where the invention is implemented using software, the software may be stored in a computer program product and loaded into computer system 900 using removable storage drive 914, hard drive 912 or communications interface 924. The control logic (software), when executed by the processor 904, causes the processor 904 to perform the function of the invention as described herein.
In another embodiment, the invention is implemented primarily in hardware using, for example, hardware components such as application specific integrated circuits (ASICs). Implementation of the hardware state machine to perform the functions described herein will be apparent to persons skilled in the relevant art(s).
In yet another embodiment, the invention is implemented using a combination of both hardware and software.
In an example software embodiment of the invention, the methods described above may be implemented in SPSS control language, but could be implemented in other programs, such as, but not limited to, C++ program language or other programs available to those skilled in the art.
The glucose meter is common in the industry and includes essentially any device that can function as a BG acquisition mechanism. The BG meter or acquisition mechanism, device, tool or system includes various conventional methods directed towards drawing a blood sample (e.g. by fingerprick) for each test, and a determination of the glucose level using an instrument that reads glucose concentrations by electromechanical methods. Recently, various methods for determining the concentration of blood analytes without drawing blood have been developed. For example, U.S. Pat. No. 5,267,152 to Yang et al. (hereby incorporated by reference) describes a noninvasive technique of measuring blood glucose concentration using near-IR radiation diffuse-reflection laser spectroscopy. Similar near-IR spectrometric devices are also described in U.S. Pat. No. 5,086,229 to Rosenthal et al. and U.S. Pat. No. 4,975,581 to Robinson et al. (of which are hereby incorporated by reference).
U.S. Pat. No. 5,139,023 to Stanley (hereby incorporated by reference) describes a transdermal blood glucose monitoring apparatus that relies on a permeability enhancer (e.g., a bile salt) to facilitate transdermal movement of glucose along a concentration gradient established between interstitial fluid and a receiving medium. U.S. Pat. No. 5,036,861 to Sembrowich (hereby incorporated by reference) describes a passive glucose monitor that collects perspiration through a skin patch, where a cholinergic agent is used to stimulate perspiration secretion from the eccrine sweat gland. Similar perspiration collection devices are described in U.S. Pat. No. 5.076,273 to Schoendorfer and U.S. Pat. No. 5,140,985 to Schroeder (of which are hereby incorporated by reference).
In addition, U.S. Pat. No. 5,279,543 to Glikfeld (hereby incorporated by reference) describes the use of iontophoresis to noninvasively sample a substance through skin into a receptacle on the skin surface. Glikfeld teaches that this sampling procedure can be coupled with a glucose-specific biosensor or glucose-specific electrodes in order to monitor blood glucose. Moreover, International Publication No. WO 96/00110 to Tamada (hereby incorporated by reference) describes an iotophoretic apparatus for transdermal monitoring of a target substance, wherein an iotophoretic electrode is used to move an analyte into a collection reservoir and a biosensor is used to detect the target analyte present in the reservoir. Finally, U.S. Pat. No. 6,144,869 to Berner (hereby incorporated by reference) describes a sampling system for measuring the concentration of an analyte present.
Further yet, the BG meter or acquisition mechanism may include indwelling catheters and subcutaneous tissue fluid sampling.
The computer, processor or PDA 1040 may include the software and hardware necessary to process, analyze and interpret the self-recorded diabetes patient data in accordance with predefined flow sequences and generate an appropriate data interpretation output. The results of the data analysis and interpretation performed upon the stored patient data by the computer 1040 may be displayed in the form of a paper report generated through a printer associated with the personal computer 940. Alternatively, the results of the data interpretation procedure may be directly displayed on a video display unit associated with the computer 940. The results additionally may be displayed on a digital or analog display device. Preferably, the results may be displayed according to the characteristics presented in
Memory 1124 also stores blood glucose values of the patient 1112, the insulin dose values, the insulin types, and the parameters used by the microprocessor 1122 to calculate future blood glucose values, supplemental insulin doses, and carbohydrate supplements. Each blood glucose value and insulin dose value may be stored in memory 1124 with a corresponding date and time. Memory 1124 is preferably a non-volatile memory, such as an electrically erasable read only memory (EEPROM).
Apparatus 1110 may also include a blood glucose meter 1128 connected to microprocessor 1122. Glucose meter 1128 may be designed to measure blood samples received on blood glucose test strips and to produce blood glucose values from measurements of the blood samples. As mentioned previously, such glucose meters are well known in the art. Glucose meter 1128 is preferably of the type which produces digital values which are output directly to microprocessor 1122. Alternatively, blood glucose meter 1128 may be of the type which produces analog values. In this alternative embodiment, blood glucose meter 1128 is connected to microprocessor 1122 through an analog to digital converter (not shown).
Apparatus 1110 may further include an input/output port 1134, preferably a serial port, which is connected to microprocessor 1122. Port 1134 may be connected to a modem 1132 by an interface, preferably a standard RS232 interface. Modem 1132 is for establishing a communication link between apparatus 1110 and a personal computer 1140 or a healthcare provider computer 1138 through a communication network 1136. Specific techniques for connecting electronic devices through connection cords are well known in the art. Another alternative example is “Bluetooth” technology communication.
Alternatively,
Accordingly, the embodiments described herein are capable of being implemented over data communication networks such as the internet, making evaluations, estimates, and information accessible to any processor or computer at any remote location, as depicted in
It should be appreciated that any of the components/modules discussed in
It should also be appreciated that any of the components/modules present in
In summary, the various embodiments of the invention propose a data analysis computerized (or non-computerized) method and system for the evaluation of the most important component of glycemic control in individuals with diabetes: glycemic variability. The method, while using only routine SMBG data, provides, among other things, an average daily risk range.
The potential implementations of the method, system, and computer program product of the various embodiments of the invention provide the following advantages, but are not limited thereto. First, the various embodiments of the invention enhance existing SMBG devices by introducing an intelligent data interpretation component capable of evaluating the effectiveness of SMBG testing by providing information about upcoming periods of possible hyperglycemia, possible hypoglycemia, increased glucose variability, and insufficient or excessive testing. They further enable future SMBG devices by the same features.
As an additional advantage, the various embodiments of the invention enhance hand-held devices (e.g. PDAs or any applicable devices or systems) intended to assist diabetes management.
Still yet another advantage, the various embodiments of the invention enhance software that retrieves SMBG data. This software can reside on patients' personal computers, or be used via Internet portal.
Moreover, the various embodiments of the invention may evaluate the effectiveness of various treatments for diabetes (e.g. insulin or variability lowering medications, such as pramlintide and exenatide).
Further still, the various embodiments of the invention may evaluate the effectiveness of new insulin delivery devices (e.g. insulin pumps), or of future closed-loop diabetes control systems.
Further yet, aspects of the present invention disclosure include, but not limited thereto, four methods and algorithms for identifying patterns of: (i) hyperglycemia, (ii) hypoglycemia, (iii) increased glucose variability, and (iv) ineffective self-testing during a time period subsequent to the time that the message is given. These algorithms use routine SMBG data collected over a period of 2-6 weeks and can be incorporated in self-monitoring devices, or software retrieving data from self-monitoring devices. All algorithms result in messages customized for the treatment pattern of a particular person, thereby providing base for customized idiosyncratic treatment.
The methods can be used separately, in combination, or in addition to previously described methods, to drive a system of messages delivered by the device to an individual with diabetes, in this case at a time proximal to a patient BG test. A theoretical model of self-regulation behavior asserts that such messages would be effective and would result in improved glycemic control.
The following references are hereby incorporated by reference herein in their entirety:
It should be appreciated that various aspects of embodiments of the present method, system, devices and computer program product may be implemented with the following methods, systems, devices and computer program products disclosed in the following U.S. Patent Applications, U.S. Patents, and PCT International Patent Applications that are hereby incorporated by reference herein and co-owned with the assignee:
PCT International Application Serial No. PCT/US2005/013792, filed Apr. 21, 2005, entitled “Method, System, and Computer Program Product for Evaluation of the Accuracy of Blood Glucose Monitoring Sensors/Devices,”
U.S. patent application Ser. No. 11/578,831, filed Oct. 18, 2006 entitled “Method, System and Computer Program Product for Evaluating the Accuracy of Blood Glucose Monitoring Sensors/Devices;”
PCT International Application Serial No. PCT/US01/09884, filed Mar. 29 2001, entitled “Method, System, and Computer Program Product for Evaluation of Glycemic Control in Diabetes Self-Monitoring Data;”
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Blood glucose self-monitoring devices are the current standard observational practice in diabetes, providing routine SMBG data that serve as the main feedback enabling patients to maintain their glycemic control. The aspects of the present invention system, method and computer program code of the present invention can, but not limited thereto, enhance existing SMBG devices by introducing data interpretation components capable of evaluating temporal glucose patterns of hyperglycemia and hypoglycemia, increased glucose variability, and inefficient self-monitoring.
Contemporary SMBG devices currently provide only general information to the patient, limited to BG readings and certain simple statistics, such as average. There are no existing pattern recognition methods that could be used for comparison.
In summary, while the present invention has been described with respect to specific embodiments, many modifications, variations, alterations, substitutions, and equivalents will be apparent to those skilled in the art. The present invention is not to be limited in scope by the specific embodiment described herein. Indeed, various modifications of the present invention, in addition to those described herein, will be apparent to those of skill in the art from the foregoing description and accompanying drawings. Accordingly, the invention is to be considered as limited only by the spirit and scope of the following claims, including all modifications and equivalents.
Still other embodiments will become readily apparent to those skilled in this art from reading the above-recited detailed description and drawings of certain exemplary embodiments. It should be understood that numerous variations, modifications, and additional embodiments are possible, and accordingly, all such variations, modifications, and embodiments are to be regarded as being within the spirit and scope of this application. For example, regardless of the content of any portion (e.g., title, field, background, summary, abstract, drawing figure, etc.) of this application, unless clearly specified to the contrary, there is no requirement for the inclusion in any claim herein or of any application claiming priority hereto of any particular described or illustrated activity or element, any particular sequence of such activities, or any particular interrelationship of such elements. Moreover, any activity can be repeated, any activity can be performed by multiple entities, and/or any element can be duplicated. Further, any activity or element can be excluded, the sequence of activities can vary, and/or the interrelationship of elements can vary. Unless clearly specified to the contrary, there is no requirement for any particular described or illustrated activity or element, any particular sequence or such activities, any particular size, speed, material, dimension or frequency, or any particularly interrelationship of such elements. Accordingly, the descriptions and drawings are to be regarded as illustrative in nature, and not as restrictive. Moreover, when any number or range is described herein, unless clearly stated otherwise, that number or range is approximate. When any range is described herein, unless clearly stated otherwise, that range includes all values therein and all sub ranges therein. Any information in any material (e.g., a United States/foreign patent, United States/foreign patent application, book, article, etc.) that has been incorporated by reference herein, is only incorporated by reference to the extent that no conflict exists between such information and the other statements and drawings set forth herein. In the event of such conflict, including a conflict that would render invalid any claim herein or seeking priority hereto, then any such conflicting information in such incorporated by reference material is specifically not incorporated by reference herein.
The present patent application claims priority from U.S. Provisional Application Ser. No. 60/876,402, filed Dec. 21, 2006, entitled “Systems, Methods and Computer Program Codes for Recognition of Patterns of Hyperglycemia and Hypoglycemia, Increased Glucose Variability, and Ineffective Self-Monitoring in Diabetes,” the entire disclosure of which is hereby incorporated by reference herein in its entirety. The present patent application is related to the International Patent Application Serial No. PCT/US2007/000370, filed Jan. 5, 2007, entitled “Method, System, and Computer Program Product for Evaluation of Blood Glucose Variability in Diabetes from Self-Monitoring Data,” the entire disclosure of which is hereby incorporated by reference herein in it's entirety.
Number | Date | Country | |
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60876402 | Dec 2006 | US |