Patent Application
20100165795
Many diabetic patients use a test meter to closely monitor their blood glucose levels. There are many blood glucose meters commercially available such as the OneTouch® Ultra® blood testing kit, available from LifeScan, Inc., Milpitas, USA. In general, a test meter works in conjunction with a disposable test strip. The test strip can include a sample receiving chamber and at least two electrodes disposed within the sample-receiving chamber in addition to the enzyme (e.g. glucose oxidase) and the mediator (e.g. ferricyanide). In use, a user can prick their finger or other convenient site to induce bleeding and introduce a blood sample to the sample-receiving chamber of a test strip, thus starting the chemical reaction. The test current generated is measured by the test meter and converted into a glucose concentration reading via a simple mathematical formula. The measurement of glucose may be based upon the specific oxidation of glucose by the enzyme glucose oxidase (GO), where the current generated is proportional to the glucose content of the sample.
Applicants believe that it is important for a person with diabetes to know the concentration of glucose in their blood at any given time. For example, the date and time of measured glucose concentrations prior to mealtimes, exercise workouts or driving can immediately influence a user's therapy or diet.
Most commercially available glucose monitoring devices have the time and date setting programmed during manufacture. However, the meter date and time can be incorrect due to drift, corruption, or user error. For example, the date and time can be cleared from the meter when the batteries are discharged or removed. In addition, a user can potentially set the date and time incorrectly when replacing the batteries.
In one exemplary embodiment, a method to set a date and time in a medical device to a time zone in which the medical device is located is provided. The medical device includes a microcontroller responsive to blood glucose values and connected to a wireless receiver. The method can be achieved by scanning a predetermined range of frequency values with the wireless receiver, in which at least one frequency value has a wireless signal, the wireless signal having a current date and time information encoded therein; determining a frequency value having a signal strength greater than as compared to any other frequency values in the predetermined range; setting the wireless receiver to the determined frequency value; and synchronizing a clock in the medical device to the current date and time encoded at the determined frequency value. In various alternatives, the scanning on can occur upon a pre-programmed event, which is selected from the group consisting of (i) an installation of a new battery into the medical device, (ii) an activation of the medical device, (iii) a predetermined time of a day, and (iv) a determination of a glucose concentration. The method may include turning off the wireless receiver. The scanning can occur upon physically transforming glucose on a test strip to an enzymatic by-product upon insertion of the test strip into a strip port connector of the medical device. The wireless receiver can be turned on for a duration of less than about 10 seconds before being turned off. The step of turning on the wireless receiver is adjusted to occur at a time interval of about one minute. The method may further include: storing the frequency value having the maximum signal strength in a memory of the medical device; and using the frequency value in the memory without performing the scanning step when the FM receiver is turned on again. The wireless signal may include a FM signal and the wireless receiver may include a FM receiver. The predetermined range of frequency values ranges from about 80 MHz to about 108 MHz. The FM signal comprises a subcarrier frequency of about 57 kHz to carry the current date and time information encoded therein at about 1187.5 bits per second. The FM signal comprises a third harmonic of a pilot tone for FM stereo. The medical device may include a glucose meter or an insulin pump.
In yet another exemplary embodiment, a method for wirelessly setting a date and time in a medical device is provided. The medical device includes a microcontroller coupled to a wireless receiver. The method can be achieved by: determining that a new battery has been installed into the medical device; automatically turning on a wireless receiver in the medical device when there is a determination that the new battery has been installed; receiving a wireless signal with the wireless receiver, the wireless signal comprising a current date and time information encoded therein; synchronizing a clock in the medical device to the wireless signal; and turning off the wireless receiver. The method further includes scanning a predetermined range of frequency values with the wireless receiver; determining a frequency value having a signal strength greater than a predetermined threshold; and setting the wireless receiver to the frequency value having a signal strength greater than the predetermined threshold. Alternatively, the method may include scanning a predetermined range of frequency values with the wireless receiver; determining a frequency value having a maximum signal strength; and setting the wireless receiver to the frequency value having the maximum signal strength. The wireless signal includes a FM signal and the wireless receiver includes a FM receiver, the FM receiver being turned on for a duration of less than about 10 seconds before being turned off. The step of turning on the FM receiver is adjusted to occur at a time interval of about one minute. The method may further include: storing the frequency value having a signal strength greater than the predetermined threshold in a memory of the medical device; and using the frequency value in the memory without performing the scanning step when the FM receiver is turned on again. The method may further include storing the frequency value having the maximum signal strength in a memory of the medical device; and using the frequency value in the memory without performing the scanning step when the FM receiver is turned on again. In a variation, the wireless signal includes a FM signal and the wireless receiver includes a FM receiver, and the predetermined range of frequency values ranges from about 80 MHz to about 108 MHz. The FM signal may include a subcarrier frequency of about 57 kHz to carry the current date and time information encoded therein at about 1187.5 bits per second. The FM signal may include a third harmonic of a pilot tone for FM stereo. The medical device includes a glucose meter or an insulin pump.
In yet another exemplary embodiment, a method for wirelessly setting a date and time in a medical device is provided. The medical device includes a microcontroller responsive to blood glucose values and connected to a wireless receiver. The method can be achieved by: determining that a glucose measurement was performed with the medical device; automatically turning on a wireless receiver in the medical device when there is a determination that the glucose measurement was performed; receiving a wireless signal with the wireless receiver, the wireless signal comprising a current date and time information encoded therein; synchronizing a clock in the medical device to the wireless signal; and turning off the wireless receiver. The method includes physically transforming glucose to an enzymatic by-product.
In yet a further exemplary embodiment, a glucose test meter is provided that includes a circuit, wireless receiver, clock, microprocessor, and display. The circuit is configured to measure a glucose concentration. The wireless receiver is configured to select a wireless signal with a signal strength greater than as compared to any other frequency values in a predetermined frequency range, the wireless signal having encoded information on a current date and time. The microprocessor is configured to turn on the wireless receiver when a glucose measurement is performed with the circuit, and synchronize the clock with the current date and time information encoded by the wireless signal with the strongest signal strength. The display is configured to illustrate a current date and time of a time zone in which the meter is located in with a measured glucose concentration thereon.
In a further exemplary embodiment, a glucose test meter is provided that includes a circuit, wireless receiver, clock, microprocessor, and display. The circuit is configured to measure a glucose concentration. The wireless receiver is configured to select a wireless signal with a signal strength greater than as compared to any other frequency values in a predetermined frequency range, the wireless signal having encoded information on a current date and time. The microprocessor is configured to turn on the wireless receiver when a new battery is installed into the glucose test meter, and synchronize the clock with the current date and time. The display is configured to illustrate a current date and time of a time zone in which the glucose meter is located in with a measured glucose concentration thereon.
In yet another embodiment, a glucose test meter is provided that includes a circuit, wireless receiver, clock, microprocessor, and display. The circuit is configured to measure a glucose concentration. The wireless receiver is configured to select a wireless signal with a signal strength greater than as compared to any other frequency values in a predetermined frequency range and in which the wireless signal has encoded information on a current date and time. The microprocessor is configured to turn on the wireless receiver when a new battery is installed into the glucose test meter, control the circuit, and synchronize the clock with the current date and time information encoded in the wireless signal. The display is configured to illustrate a current date and time therein of a time zone in which the glucose meter is located in with a measured glucose concentration thereon, the display being connected to the microprocessor.
These and other exemplary embodiments, features, advantages will be apparent when taken with reference to the following detailed description of the exemplary embodiments of the invention in conjunction with the accompanying drawings that are briefly described below.
The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate presently preferred exemplary embodiments of the invention, and, together with the general description given above and the detailed description given below, serve to explain features of the invention, in which:
The following detailed description should be read with reference to the drawings, in which like elements in different drawings are identically numbered. The drawings, which are not necessarily to scale, depict selected exemplary embodiments and are not intended to limit the scope of the invention. The detailed description illustrates by way of example, not by way of limitation, the principles of the invention. This description will clearly enable one skilled in the art to make and use the invention, and describes several exemplary embodiments, adaptations, variations, alternatives and uses of the invention, including what is presently believed to be the best mode of carrying out the invention.
As used herein, the terms “about” or “approximately” for any numerical values or ranges indicate a suitable dimensional tolerance that allows the part or collection of components to function for its intended purpose as described herein. In addition, as used herein, the terms “patient,” “host,” “user,” and “subject” refer to any human or animal subject and are not intended to limit the systems or methods to human use, although use of the subject invention in a human patient represents a preferred exemplary embodiment.
In an exemplary embodiment, a medical device can be configured to synchronize to the current time (CT) component of a frequency modulated (FM) signal to ensure that the medical device has accurate date and time information. The FM signal can in the form of a Radio Data System (RDS) signal where the current time (CT) feature allows synchronization of an internal clock within the receiver, giving accuracy to within 100 milliseconds of UTC (Universal Time Coordinate).
Radio Data System (RDS), also known as Radio Broadcast Data System in the US, was first introduced to address the increasing problem of tuning conventional radios due to the vast number of different frequencies being used to transmit radio programs. RDS is a communications protocol that uses a conventional FM signals to send digital information in addition to the typical analog information for reproducing sound. A 57 kHz sub-carrier is used to carry data at 1187.5 bits per second, and as the third harmonic of the pilot tone for FM stereo, 57 kHz was chosen as it would provide minimal interference with the pilot tone. Details of utilization of the RDS signal are provided in GB2238438, which is hereby incorporated by reference in its entirety. Additional details regarding automatic time setting using RDS are provided in U.S. Pat. No. 7,031,696, which is hereby incorporated by reference in its entirety.
Integrated circuits (IC) are commercially available having an FM receiver and a RDS decoder on the same chip. Chipsets offering RDS capabilities intended for portable devices e.g. mobile phones and MP3 players are commercially available from companies such as Silicon Labs of Austin, Tex., and NXP Semiconductors. Examples include, but are not limited to the Si4705 or Si4706 chips available from Silicon Laboratories, which provide FM digital tuning integrated with a stereo decoder and consume less than 10 mm2 of board space. Such a receiver may support worldwide FM frequencies in the range 64 to 108 MHz with adjustable seek parameters. These wireless receivers have an advantage of encompassing an embedded antenna 25, which helps reduce the size of the device. An embedded antenna may be in the form of a PCB trace antenna, wire antenna or loop antenna for example.
Referring again to
In an exemplary embodiment, the wireless receiver 20 can be automatically turned on, indicated here by step 104. The process of automatically turning on can occur upon the occurrence of a pre-programmed event 102, such as for example but not limited to, a battery replacement, an activation of the medical device (sensor 2 or pump 3), an occurrence of a predetermined time of day, or an occurrence of a blood glucose measurement being performed. Whilst this list provides some exemplary example events, it is not exclusive and other events are intended to be included. As used herein, the term “automatically” means that a step or a plurality of steps can be initiated due to predetermined occurrence of events or activities without requiring an intended input by the user or operator of the medical device to check or verify the time or date on the medical device.
In an exemplary embodiment, the wireless receiver 20 may be turned on in order to receive current date and time information following replacement of a battery from the medical device. In the short time that it takes a user to replace the battery (i.e., typically 1 to 2 minutes under normal circumstances) the internal clock information may be lost. Upon insertion of a new battery, the software of the medical device would recognize that the battery has been changed and immediately, or at some predetermined time interval after receiving a new battery, instruct the wireless receiver to turn on to obtain updated time and date information following a protocol such as those outlined in
In another exemplary embodiment, the receiver IC may be turned on upon activation of the medical device (sensor 2 or pump 3). Many conventional devices such as glucose measurement meters power on upon pressing an ‘on’ or ‘ok’ button or upon detection of a test strip being inserted into the meter in preparation to perform a test. In this exemplary embodiment, the wireless receiver can be configured to turn on as part of the meter's start up protocol, therefore every time the meter is used to perform a measurement or perhaps the patient activates the meter to view previous results, then the receiver may begin the protocol to receive and update the date and time information.
In another exemplary embodiment the wireless receiver can be programmed to turn on and retrieve updated date and time information at one or more predetermined times of day, for example at 12 noon. In another example exemplary embodiment the wireless receiver can be turned on to coincide with each time a measurement such as blood glucose measurement is made. For most patients this would result in several date and time updates every day, ensuring that these settings are highly accurate and therefore allowing better data analysis and trend identification by the HCP.
Once powered on, the wireless receiver performs a scan (also known as a sweep or auto-seek) across a predetermined frequency range, as shown by step 106 in which at least one frequency value has a wireless signal. The predetermined frequency range may include the FM frequency band, which ranges from approximately 80 to 108 MHz. The scan may alternatively be in size steps of 100 kHz. As the receiver scans the frequency range it detects all the station frequencies present as shown by step 108, and which may be categorized as having a signal strength greater than a predetermined threshold. In an exemplary, a number of frequency stations exhibiting the strongest signal strengths may be stored in the memory of the device, as shown by step 110, for example as ‘Station 1’, along with ‘N’ number of additional frequencies with strong signals stored as ‘Station 2’ up to ‘Station ‘N’, as will be described in more detail in relation to
It is intended by applicants that the steps outlined in tuning protocol 100 may be performed in any order and not restricted to the order described. In addition any one or more of the steps may be utilized as needed.
The internal clock of the medical device (sensor 2 or pump 3) may be a ‘real time clock’ (RTC) in the form of an integrated circuit that keeps track of current time with an estimated error of approximately 30 to 40 minutes per year if left unchecked. Software within the meter continues to advance the RTC every second. Once the CT is decoded from the RDS reception then the RTC is synchronized with this current time.
Alternatively, the RDS reception may run with on-screen diagnostics visible to the user. This may be useful when a new meter is switched on for the first time for example as it allows the user to acknowledge that the date and time parameters have been set accurately. Yet in an alternative exemplary embodiment, the RDS reception may run without any screen output i.e. the screen would be blank as if the meter was switched off. In this mode, the user would not have any knowledge of the process being performed by their meter. Additionally, leaving the display powered off has the added advantage of conserving battery power.
Following a power on of the receiver IC upon the occurrence of a pre-programmed event, as shown by step 202, such as one or more of those example events listed and described in relation to
If however, the last known good frequency is no longer valid at as shown by step 206, then the receiver may access the memory of the medical device and look for any station frequencies previously stored. Any frequencies stored in the memory are then loaded into the receiver, as shown by step 208. The wireless receiver 20 may then determine if there is a first frequency stored in “Station 1” for example, as shown by step 210. If a valid frequency is found, then the receiver may tune to this frequency and begin RDS reception, 212. In one exemplary embodiment, the frequency stored in “Station 1” corresponds to the frequency exhibiting the strongest signal strength during the last scan of the frequency bandwidth. If the frequency stored in Station 1 is not valid, then the receiver may determine if there is a valid frequency stored within “Station 2” for example, as shown by step 220, and may continue this process ‘N’ number of times, as shown by step 222, depending on how many frequencies may be stored. RDS reception begins once a valid station frequency is found and tuned in to. Once the current time (CT) is received, the meter software decodes the data, as shown by step 214, and the internal clock is synchronized with the new, current time, 216. The wireless receiver 20 can then be powered down or turned off to conserve battery power, as shown by step 218.
Programming the receiver to tune directly to a previously stored or preset frequency and not perform a scan of the entire band may reduce the time it takes for new, updated date and time information to be received. If a signal is available at the previously stored frequency then RDS reception can start right away, the current time is received and decoded, then the internal clock of the meter can be synchronized with this new, updated time and the receiver can be turned off. Use of a previously stored frequency allows the entire date and time updating process to be completed within a short time period, for example approximately 2 to 3 seconds. Eliminating the step of scanning the frequency bandwidth and searching for the station frequencies each time updated date and time information is required can reduce the overall time that the wireless receiver 20 is powered on, thereby minimizing battery consumption.
If however, the frequencies stored in the memory of the medical device are no longer valid, for example if the patient has moved location, then the receiver may perform a scan across the predefined frequency band, starting at 88 MHz and advancing to 108 MHz for example, as shown by step 224. If at least one frequency is detected and has a wireless signal having encoded information on date and time information, as shown by step 226, then ‘N’ number of the strongest frequencies can be stored within the memory of the meter, 230, and the tuning procedure can start, as shown by step 212. If the FM signal is very weak and/or no station frequencies are detected then the user may be provided with the option to set the date and time manually, as shown by step 228.
If, however, the signal from the previously stored frequency “Station 1” is not available or sufficient to enable RDS reception then the receiver may check the frequency stored in “Station 2”, as shown by step 416, and so on up to ‘N’ number of different station frequencies previously stored in the meter memory, 418. If none of the previously stored frequency values yield a valid signal from which to begin RDS reception, then the wireless receiver 20 may be commanded to perform a scan across the predetermined frequency range, 420. The wireless receiver 20 will search for stations having a frequency value with a wireless signal having encoded information on date and time information and having a signal strength exceeding a predefined threshold signal strength value, as shown by step 422. ‘N’ number of station frequencies having a signal strength greater than the predefined threshold value may then be stored in the memory of the meter for subsequent use, 424. The receiver may then tune to one of the stored frequency values and begin RDS reception. Once the current time information is received, the data is decoded and the internal clock of the meter synchronized with the new, updated date and time information prior to the receiver being turned off. Alternatively, if no FM signal is available then the user may be provided with the option to update the time and date information manually, as shown by step 426.
Storing the station frequencies identified as having the strongest signal strengths, or alternatively exceeding a predefined threshold strength value, reduces the number of processes the wireless receiver 20 has to perform in order to obtain current date and time information encoded therein. Less processes steps to perform will typically correlate to a reduction in the length of time the receiver is required to be powered on, therefore power consumption is kept to a minimum. For many people, their general geographic location may not change a great deal from day to day, therefore having the option for the meter to remember the frequency of the station previously tuned into to obtain RDS date and time information provides several advantages. Such advantages include potentially increased processor performance as well as reduced power consumption, ultimately leading to an increased battery lifetime and hence more reliable date and time information available to the patient and their HCP for use in the managing of the patient's condition. Accurate date and time information allows trends and patterns in a patient's historical measurement data to be reliably identified and analyzed, and may lead to improved care for the patient.
FM signals, in most atmospheric conditions, do not travel long distances, and may also be affected by large obstructions such as built-up areas or hills for example. Therefore many transmitters are required to provide adequate signal coverage. If a patient travels locally within a radius of 100 km for example, then the receiver may need to re-tune to a different frequency to obtain the strongest signal in the new location. Neighbouring transmitters may also use different FM frequencies to avoid interference. In an exemplary embodiment, the wireless receiver 20 would scan the frequency band and detect the local station frequencies without requiring any user intervention. Operation of the receiver may be completely invisible to the user.
If the user does travel to a different country or location having a different time zone from where they normally reside, then the wireless receiver 20 would be able to scan the frequency bandwidth to detect the stations having the strongest signals, alternatively with a strength exceeding a predefined threshold value, and tuning in to that frequency to receive the RDS information. Furthermore, the current time (CT) is always transmitted in universal time (UTC) that is the same throughout the world, and in addition a local offset is also transmitted depending in which time zone the reception has occurred. Therefore when a blood glucose reading has taken place, the UTC and local offset can be stored along with the glucose result, ensuring that any time differences between glucose readings are maintained despite movement of the patient across time zones. It is intended that the exemplary tuning protocols provided herein may be used either individually or they may be used in combination with one-another.
Referring back to
Applicants believe that an advantage is provided in that the time and date setting of a patient's medical device can be completely automatic and hence invisible to the user. Incorrect time and date setting can be a source of complaint from users. This may be due to the complexity of configuring the meter, or understanding the need to check and possibly update these settings. Automatically updating the time and date setting using FM RDS wireless reception virtually eliminates this source of error, and provides the HCP with reliable data allowing easier and better monitoring of the patients historical measured results, which may lead to improved regulation and care for the patient.
A further advantage provided by automatic time and date setting using FM RDS is the possibility to design a meter that has no user operable buttons, i.e., completely button-less. If there is no requirement for the user to enter information or set any parameters such as time, date or calibration code for example, then the possibility exists to provide the patient with an extremely easy to use meter that has no buttons. Those with reduced dexterity may particularly appreciate this type of meter as they may find it very difficult or virtually impossible to navigate through settings and options using the small buttons provided on many conventional monitoring meters. Analysis of measurement data, such as averages and graphs of results, would still be possible by both the patient and/or the HCP using the software available for use on a computer (such as a diabetes management software provided by LifeScan Inc.).
While preferred exemplary embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such exemplary embodiments are provided by way of example only. For example, the invention can be applied not only to glucose meters, but can also be applied to any medical device such as insulin infusion pump, continuous glucose monitoring system and the like. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. Various alternatives to the exemplary embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.
