|
Medical Patent Abstract
Apparatus and method for managing chronic home care of patients
with one or more implanted medical devices (IMDs) includes a mobile
portable device for use by a visiting nurse. Specifically, the portable
device integrates various systems to enable the nurse to schedule
her day and get directions to a first and subsequent visit destination
via a GPS system or equivalent. The portable device includes an
identification system including a security protocol to identify
the nurse/home health care provider. Additionally, the portable
device incorporates a communication system such as a cellular phone
that would enable the nurse to connect to other clinical support
personnel such as a doctor or a specialist. The portable device
further includes a wireless communication system that enables communication
between the portable device and one or more IMDs in a patient. Upon
arrival at the patient's home, the nurse may download data from
the one or more IMDs directly into the portable device. This data
could in turn be downloaded immediately or later to a remote viewing
center via conventional data transmission systems. Other medical
data such as blood pressure measurements and vital physiologic signals
may be entered into the portable device using a digitizer pen, voice
input or equivalent. Similar to the IMD data, this medical data
could be transmitted to the remote location from the portable device.
Medical Patent Claims
What is claimed:
1. A portable extender adapted for use by a visiting nurse, the
extender comprising: a video camera; means for establishing a wireless
data communication with a medical device implanted in a patient
being visiting by the nurse; means for downloading diagnostic data
from the medical device; means for establishing a wireless data
communication with a remote location; means for downloading secure
data corresponding to a treatment and prescription plan for the
patient from the remote location; means for planning and organizing
a daily schedule of patient visits for the visiting nurse; and a
touch screen coupled to and providing means for a user to activate
the video camera, the means for establishing the wireless data communication
with the medical device, the means for establishing a wireless data
communication with the remote location, the means for downloading
the diagnostic data, the means for downloading the secure data,
and the means for planning and organizing a daily schedule of patient
visits for the visiting nurse.
2. The extender of claim 1 wherein the extender further comprises
a means for transferring video images collected by the video camera
to a remote location.
3. The portable extender of claim 1, further comprising a GPS system.
4. The portable extender of claim 1, further comprising means to
transfer the diagnostic data to the remote location.
5. The extender of claim 1, further comprising a cell phone including
a microphone.
6. The extender of claim 1, further comprising a data storage disk.
7. The extender of claim 1, further comprising means for providing
identifying information, via the extender, in order to gain access
to the secure data.
8. A portable extender adapted for use by a visiting nurse, the
extender comprising: means for establishing a wireless data communication
with a remote location; means for downloading a patient visit schedule
from the remote location; a video camera for verifying the identity
of the visiting nurse; means for downloading secure data corresponding
to a patient treatment and prescription plan from the remote location
in response to verifying the identity of the visiting nurse; means
for displaying the patient treatment and prescription plan; means
for establishing a wireless data communication with a medical device
implanted in a patient being visited by the nurse; means for downloading
diagnostic data from the medical device; and a touch screen coupled
to and providing means for the nurse to activate the means for establishing
the wireless data communication with the remote location, the video
camera, the means for downloading the secure data, the means for
establishing the wireless data communication with the medical device,
and the means for downloading the diagnostic data.
9. A method implemented in a portable extender, comprising: establishing
a wireless data communication with a remote location in response
to a touch screen activation by a user; downloading a patient visit
schedule from the remote location in response to establishing the
wireless data communication; verifying the identity of the user
using a video camera image acquired by the portable extender; downloading
secure data corresponding to a patient treatment and prescription
plan from the remote location in response to verifying the identity;
displaying the patient treatment and prescription plan; establishing
a wireless data communication with a medical device implanted in
a patient in response to a touch screen activation by the user;
and downloading diagnostic data from the medical device in response
to establishing the wireless data communication.
Medical Patent Description
FIELD OF THE INVENTION
The present invention generally relates to medical devices and
communications systems. Specifically, the invention relates to a
portable extender that is in wireless communication with a device
implanted in a patient. The extender is a computer that transmits
and exchanges data between a patient station and a remote expert
station. The patient station and remote expert station maintain
data communication via network systems such as the Internet, worldwide
web, intranet, extranet, or other similar network systems.
BACKGROUND OF THE INVENTION
The concept of home health care began in the 1850's when traveling
health care professionals, usually physicians, provided in-home
visits to patients who were in need of health care and were unable
to seek such care outside of the home. From the outset, however,
traveling between various patients' homes constituted "downtime"
for the health care professional. In the middle of the twentieth
century, this type of medical service was transferred from the physician
to nurses or other health care workers. During the past decade,
providing home health care has become more difficult due to the
shortage of health care professionals in general and, in particular,
of those who provide home health care. Because of this shortage
as well as the increase in medical costs, home health care visits
may be limited to basic needs and/or medical emergencies.
On the other hand, the number of patients who are home bound has
been increasing. Many terminally ill patients, such as heart failure
or cancer patients among others, are sent home to live with their
families who provide 24-hour care. Other patients with chronic health
problems reside in their homes where they receive necessary support
and treatment on an "as needed" basis. Through the auspices
of hospices or other support groups, nurses or health care workers
provide medical care and evaluation on a periodic basis. Although
these visits provide the contracted services, nonetheless they still
suffer from administrative "overload" tasks.
The nurse or other health care worker may spend much of her time
on the phone, contacting physicians, druggists, plan administrators,
the family members of the patient, and so on. In addition, that
same nurse must take notes and/or fill out health plan or HICFA
forms to ensure reimbursement for the services provided. As a result,
a large percentage of the time during the visit has little to do
with providing medical care and evaluation of the patient.
Patients with implantable medical devices (IMDs) also require regular
checkups to determine whether their IMDs have been functioning properly.
Most patients with IMDs must be monitored bi-annually, at the very
least. Such monitoring may occur transtelephonically from the patient's
home or via telemetry as has been disclosed in U.S. Pat. No. 5,752,976
issued to Duffin, et al, "World Wide Patient Location and Data
Telemetry System for Implantable Medical Devices", incorporated
herein by reference in its totality. Still, some of the very elderly
patients with IMDs, whether single or multiple, require periodic
visits from health care nurses/workers to evaluate their IMD(s).
Various solutions to these issues, in addition to the '976 patent,
have been suggested in the art. U.S. Pat. No. 5,553,609 issued to
Chen, et al, "Intelligent Remote Visual Monitoring System for
Home Health Care Service" generally discloses a computer-based
remote visual monitoring system connected transtelephonically to
a remote master-monitoring computer. This system is intended for
use by the visiting nurse during an in-home patient health care
visit. Separate audio and visual equipment facilitates communication
between the patient's home and a remote station. The system has
several layers, including units in the patient's home, the caregiver's
office, and the supervisory control center. Audiovisual equipment
in the patient's home and at the caregiver's office provides two-way
communications during a home visit. There is also a provision for
generating and maintaining the patient's medical records. The '609
patent, however, does not appear to teach a method for monitoring
patients with IMDs. U.S. Pat. No. 5,749,908 issued to Snell, "Methods
and Apparatus for Annotating Data in an Implantable Device Programmer
Using Digitally Recorded Sound", teaches a system in which
data from an IMD patient may be downloaded to a programmer using
digitally recorded voice signals and/or digitizer pen. A physician,
upon reviewing the data, can listen to the voice annotations by
using a playback mode. While the '908 patent addresses issues that
are specific to patients with IMDs, it implements the use of a device
programmer. Further, desirable features such as a method to address
or deal with the previously cited administrative tasks, that consume
so much time during a typical visit, appear to be undisclosed by
the '908 patent.
U.S. Pat. No. 5,872,923 issued to Schwartz, et al, "Collaborative
Video Conferencing System" discloses a video conferencing system,
wherein multiple parties at different locations can view, and modify,
a common image on their computer displays. The invention also provides
a video camera at each computer, which takes a video picture of
each party. The systems described in the '609 and '923 patents,
however, appear to depend on static, non-mobile computer terminals.
What is needed to optimize the tasks for the home health care worker
is a mobile device akin to a Personal Data Assistant (PDA) disclosed
in U.S. Pat. No. 6,016,476, issued to Maes, et al, "Portable
Information and Transaction Processing System and Method Utilizing
Biometric Authorization and Digital Certificate Security" incorporated
herein by reference in its totality. The PDA in this patent is a
portable device with a touch screen, with a microphone and local
CPU for processing voice commands and user verification. While the
'476 patent is intended for managing financial data, its general
concept may underlie certain aspects of the present invention. One
aspect of particular interest, for example, is a method to verify
the identity of the user via voice recognition. An alternative method
for identifying the user is disclosed in U.S. Pat. No. 5,787,186
issued to Schroeder "Biometric Security Process for Authenticating
Identity and Credit Cards, Visas, Passports and Facial Recognition"
in which a person's facial structure is used to verify a person's
identity. The '186 patent teaches the use of an image capturer such
as a scanner or a video camera to capture facial features that are
transferred to the CPI for an analysis of a basic facial image.
If matched to the stored image, the user can gain entry into files
containing secure data.
Inputting data may be accomplished via a digitizer pen, tethered
to a PDA, as disclosed in U.S. Pat. No. 5,756,941, issued to Snell
"Retractable Pen Tether for a Digitizer Pen and Method of Attaching
a Digitizer Pen to a Digitizer", incorporated herein by reference
in its totality. Such a pen is intended for use in a hand-held computer
and is kept in a pen storage chamber incorporated within the body
of the PDA. Such digitizer pens, though not tethered to the PDA
as taught by the '941 patent, are now commonly available with commercial
PDAs. Such common use should make these digitizer pens an easy-to-use
tool for the home health care worker.
A health care worker must often spend a good deal of time trying
to determine where she must go for her next visit, especially if
the next visit is a new patient. U.S. Pat. No. 6,177,905 issued
to Welch "Location-Triggered reminder for Mobile User Devices",
discloses how to equip a PDA with a global positioning system (GPS)
receiver. The user can program into the PDA geographical coordinates
of locations and, thereafter, give them names. These names can then
be called up and, by reference to one's present location, provide
directions to a new location which, in this context, could be the
next visit.
What is needed is a system that provides all the benefits of home
health care service with methods and structures implemented to enable
monitoring of IMD patients on a regular basis.
SUMMARY OF THE INVENTION
In one aspect of the present invention a visiting nurse is enabled
to schedule her day and get directions to the first and subsequent
visits via a GPS or equivalent tool. Upon arriving at the patient's
home, she can download data from the IMD directly into a mobile
portable extender device. In yet another aspect of the invention,
data from the extender could be downloaded immediately or later
to a remote viewing center.
Yet another feature enables the nurse to ask questions by initiating
voice and/or video communication with a physician via the audio
and video capabilities of the portable extender device. Further,
the nurse can call such an expert to discuss patient treatment or
other clinical procedures. Other medical data such as blood pressure
(BP) measurements from those gathered via a BP cuff can be entered
via a digitizer pen or voice input. Furthermore, the nurse may automatically
change a prescription by contacting a druggist electronically. All
these actions are accomplished via a cellular connection that allows
voice, video, and text communication with remote facilities. Documentation
may be required, such as a Medicare 485 form that documents the
actions taken during a visit. This form can be downloaded to the
portable extender and automatically filled out. Thus, many time-consuming
data management tasks are centralized in and by the portable extender
device.
All of these capabilities are available to the nurse in the present
invention. The nurse need not make multiple phone calls to contact
different people, nor rewrite the prescription back at the office
and then send it out to the patient or the pharmacy.
Thus, monitoring of the patient in the home is expedited. Shorter,
more focused visits would allow the nurse to visit approximately
50% more patients in a day. In one embodiment, the portable extender
contains a microphone as well as a video camera similar to the video
cam found in many PCs. Contact with remote location occurs via a
cellular phone or equivalent communication device contained in the
portable extender. The portable extender could be easily assembled
with off-the-shelf materials or may implement proprietary software
loaded into a commercially available device such as the Fujitsu
Stylistic 1200.TM. Pen Tablet.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a body-implantable device system in
accordance with the present invention, including a hermetically
sealed device implanted in a patient and an external transceiver.
FIG. 2 is a block diagram of the implanted device from FIG. 1.
FIG. 3a is a block diagram showing the communication system in
accordance with the present invention from the implanted device
of FIG. 2.
FIG. 3b is a block diagram showing the communication system from
the portable extender device of FIG. 1.
FIG. 4 is an illustration of one embodiment of the portable extender
device.
FIG. 5 is a flow diagram of the steps that a visiting health care
nurse might follow with the use and help of the portable extender
device.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of an implantable medical device system
adapted for use in accordance with the present invention. The medical
device system shown in FIG. 1 includes implantable device 10--a
pacemaker for illustration purposes--that has been implanted in
patient 12. In accordance with conventional practice in the art,
pacemaker 10 is housed within a hermetically sealed, biologically
inert outer casing, which may itself be conductive so as to serve
as an indifferent electrode in the pacemaker's pacing/sensing circuit.
One or more pacemaker leads, collectively identified with reference
numeral 14 in FIG. 1 are electrically coupled to pacemaker 10 in
a conventional manner and extend into the patient's heart 16 via
a vein 18. Disposed generally near the distal end of leads 14 are
one or more exposed conductive electrodes for receiving electrical
cardiac signals and/or for delivering electrical pacing stimuli
to heart 16. As will be appreciated by those of ordinary skill in
the art, leads 14 may be implanted with their distal end(s) situated
in the atrium and/or ventricle of heart 16.
The present invention will be described herein in an embodiment
that includes a pacemaker. Those of ordinary skill in the art, however,
with the benefit of the present disclosure will appreciate that
the present invention may be practiced in connection with numerous
other types of IMDs such as defibrillators, cardioverters, neurostimulators,
insertable loop recorders (ILR) such as the Medtronic.RTM. Reveal.TM.,
heart failure monitors such as the Medtronic.RTM. Chronicle.TM.,
and the like. Indeed, the present invention may be practiced in
any application in which it is desirable to provide a communication
link between two physically separated components. Also depicted
in FIG. 1 is a portable extender unit 20 for non-invasive, wireless
communication with implanted device 10 via uplink and downlink communication
channels, to be hereinafter described in further detail.
FIG. 2 is a block diagram of the electronic circuitry that makes
up pulse generator 10 in accordance with the presently disclosed
invention. As can be seen from FIG. 2, pacemaker 10 comprises a
primary stimulation control circuit 32 for controlling the device's
pacing and sensing functions. The circuitry associated with stimulation
control circuit 32 may be of conventional design, in accordance,
for example, with what is disclosed U.S. Pat. No. 5,052,388 issued
to Sivula et al., "Method And Apparatus For Implementing Activity
Sensing In A Pulse Generator". To the extent that certain components
of pulse generator 10 are conventional in their design and operation,
such components will not be described herein in detail, as it is
believed that design and implementation of such components would
be a matter of routine to those of ordinary skill in the art. For
example, stimulation control circuit 32 in FIG. 2 includes sense
amplifier circuitry 34, stimulating pulse output circuitry 36, a
crystal clock 40, a random-access memory and read-only memory (RAM/ROM)
unit 42, and a central processing unit (CPU) 38, all of which are
well-known in the art. Pacemaker 10 also includes internal communication
circuit 44 so that it is capable of wirelessly communicating with
portable extender device 20.
With continued reference to FIG. 2, pulse generator 10 is coupled
to one or more leads 14 which, when implanted, extend transvenously
between the implant site of pulse generator 10 and the patient's
heart 16, as previously noted with reference to FIG. 1. Physically,
the connections between leads 14 and the various internal components
of pulse generator 10 are facilitated by means of a conventional
connector block assembly 11, shown in FIG. 1. Electrically, the
coupling of the conductors of leads and internal electrical components
of pulse generator 10 may be facilitated by means of a lead interface
circuit 30 which functions, in a multiplexer-like manner, to selectively
and dynamically establish necessary connections between various
conductors in leads 14, including, for example, atrial tip and ring
electrode conductors ATIP and ARING and ventricular tip and ring
electrode conductors VTIP and VRING, and individual electrical components
of pulse generator 10, as would be familiar to those of ordinary
skill in the art. For the sake of clarity, the specific connections
between leads 14 and the various components of pulse generator 10
are not shown in FIG. 2, although it will be clear to those of ordinary
skill in the art that, for example, leads 14 will necessarily be
coupled, either directly or indirectly, to sense amplifier circuitry
34 and stimulating pulse output circuit 36, in accordance with common
practice, such that cardiac electrical signals may be conveyed to
sensing circuitry 34, and such that stimulating pulses may be delivered
to cardiac tissue, via leads 14. Also not shown in FIG. 2 is the
protection circuitry commonly included in implanted devices to protect,
for example, the sensing circuitry of the device from high voltage
stimulating pulses.
As previously noted, stimulation control circuit 32 includes central
processing unit 38 which may be an off-the-shelf programmable microprocessor
or micro controller, but in the present invention is a custom integrated
circuit. Although specific connections between CPU 38 and other
components of stimulation control circuit 36 are not shown in FIG.
2, it will be apparent to those of ordinary skill in the art that
CPU 38 functions to control the timed operation of stimulating pulse
output circuit 36 and sense amplifier circuit 34 under control of
programming stored in RAM/ROM unit 42. It is believed that those
of ordinary skill in the art will be familiar with such an operative
arrangement.
With continued reference to FIG. 2, crystal oscillator circuit
40, in the presently preferred embodiment a 32,768-Hz crystal controlled
oscillator provides main timing clock signals to stimulation control
circuit 32. Again, the lines over which such clocking signals are
provided to the various timed components of pulse generator 10 (e.g.,
microprocessor 38) are omitted from FIG. 2 for the sake of clarity.
It is to be understood that the various components of pulse generator
10 depicted in FIG. 2 are powered by means of a battery (not shown)
that is contained within the hermetic enclosure of pacemaker 10,
in accordance with common practice in the art. For the sake of clarity
in the Figures, the battery and the connections between it and the
other components of pulse generator 10 are not shown.
Stimulating pulse output circuit 36, which functions to generate
cardiac stimuli under control of signals issued by CPU 38, may be,
for example, of the type disclosed in U.S. Pat. No. 4,476,868 to
Thompson, entitled "Body Stimulator Output Circuit", which
patent is hereby incorporated by reference herein in its entirety.
Again, however, it is believed that those of ordinary skill in the
art could select from among many various types of prior art pacing
output circuits that would be suitable for the purposes of practicing
the present invention.
Sense amplifier circuit 34, which is of conventional design, functions
to receive electrical cardiac signals from leads 14 and to process
such signals to derive event signals reflecting the occurrence of
specific cardiac electrical events, including atrial contractions
(P-waves) and ventricular contractions (R-waves). Sense amplifier
circuit 34 provides these event-indicating signals to CPU 38 for
use in controlling the synchronous stimulating operations of pulse
generator 10 in accordance with common practice in the art. In addition,
these event-indicating signals may be communicated, via uplink transmission,
to portable extender device 20 via telemetry coil 45. Those of ordinary
skill in the art will appreciate that pacemaker 10 may include numerous
other components and subsystems, for example, activity sensors and
associated circuitry. The presence or absence of such additional
components in pacemaker 10, however, is not believed to be pertinent
to the present invention, which relates primarily to the implementation
and operation of communication subsystem 44 in pacemaker 10, and
an associated communication subsystem in portable extender device
20.
Referring to FIG. 3a, there is shown a simplified block diagram
of communication subsystem 44 from pacemaker 10, in accordance with
the present invention. Communications subsystem may be, for example,
of the type disclosed in U.S. Pat. No. 5,843,139 to Goedeke, et
al., "Adaptive Performance-Optimizing Communication System
for Communicating With an Implanted Medical Device", which
patent is incorporated by reference herein in its entirety.
Communication subsystem 44 in implantable device 10 includes a
receiver 102 and a transmitter 104 each coupled to antenna 45 (FIG.
2) which may be implemented as a multiple-turn wire coil, a stub
wire, or a pacing lead. In one embodiment, communication subsystem
44 further includes error detection circuitry 106, signal strength
detection circuitry 108, and noise strength detection circuitry
110. Generally, error detection circuit 106, signal strength detection
circuit 108, and noise strength detection circuit 110, can be called
system performance monitoring circuits which function to dynamically
monitor one or more aspects of communication system 44. Error detection
circuit 106, for example, may utilize well-known error detection
techniques to determine the bit error rate (BER) and the SNR of
digital information received by receiver 102. Signal strength detector
circuit 108 may consist of a logarithmic amplifier that detects
and filters the RF signal (or IF signal if downconverted) to provide
an RSSI (received signal strength indicator) output that gives a
voltage proportional to the logarithm of the signal strength at
the receiver's RF input. Detector 108 will only respond to the signal
present within the receiver pass band. In this way, the desired
signal strength (actually, signal plus noise) can be measured. Likewise,
the noise can be measured with the same apparatus under the condition
of a known period with no received transmission. In this way the
signal-to-noise ratio of the received signal can be measured by
a simple comparison of the signal and the noise RSSI samples. This
method, as would be appreciated by those of ordinary skill in the
art, would effectively implement circuit 110 as well as 108 in FIG.
3.
With continued reference to FIG. 3a, circuits 106, 108 and 110
are in turn coupled to control circuit 112 that, in one embodiment,
may be a custom integrated circuit or equivalent. Control circuit
112 in communication subsystem 44 functions to control various aspects
of communication operation in device 10, and further functions to
cause data to be transmitted to portable extender device 20 (FIG.
4). For example, as shown in FIG. 3a, control circuit 112 is coupled
to transmitter power control circuit 114, such that under command
of control circuit 112, the power of signals transmitted by transmitter
104 can be adjusted up or down. Similarly, control circuit 112 is
coupled to data rate control circuit 116 that controls the rate
at which data is transmitted from transmitter 104. Control circuit
112 is also coupled to an antenna pattern (field strength as a function
of position) control circuit 118, so that the antenna pattern for
reception and transmission of transmitted signals may be dynamically
configured during operation of communication subsystem 44 and to
receiver circuit 102 so that the bandwidth of the bandpass filter
therein may be adjusted.
Control circuit 112 is responsive to prioritized sets of operational
goals to be accomplished in conjunction with each of a plurality
of telemetry transmission types, stored in RAM/ROM 42 (FIG. 2).
In response to an identification of the type of telemetry to follow,
processor 38 (FIG. 2) instructs control circuit 112 as to operational
parameters and through control circuitry 112 monitors the outputs
of the performance monitoring circuits 106, 108, 110, 111. Under
control of processor 38, control circuitry adjusts the various parameter
adjustment circuits to achieve the operational goals stored in RAM/ROM
42, in order of their priorities. Control circuitry 112 in some
cases adjusts the operational parameters associated with transmitter
104 or receiver 102. Alternatively, parameter adjustment commands
may be formatted by processor 38 for transmission by transmitter
104 to receiver 122 (FIG. 3b), to control corresponding parameter
adjustment circuits associated with transmitter 120 (FIG. 3b).
In accordance with one aspect of the invention, communication subsystems
44 and portable extender device 20 (FIG. 3a) are preferably capable
of exchanging information with each other, such that IMD 10 can
transmit, upon command, its stored data related to operational parameters
to portable extender device 20. For example, if signal strength
detector circuit 108 in subsystem 44 determines that the received
signal transmitted from transmitter 120 is unacceptably weak, control
circuitry 112 can initiate transmission of a command to subsystem
100 instructing transmitter 120 to increase its transmission power.
In accordance with one aspect of the present invention, the performance
goals of the communication system, and the standards or limits imposed
upon operational parameters, may themselves be adjusted on a dynamic
basis. In this scenario, it would be desirable to increase the minimum
transmission range to be maintained by the communication system,
so that portable extender device 20 can establish telemetric communication
with the patient's implanted device from a longer-than-normal distance,
e.g., from bedside or even across the room.
Typically a telemetry system employing the present invention will
include a plurality of performance goals applicable in conjunction
with each of a variety of telemetry transmission types. In most
cases it is envisioned that the performance goals will include one
or more absolute requirements for a transmission to be considered
acceptable. For example, in most cases a maximum error rate will
be the highest priority performance goal, with acceptable error
rates differing based on the telemetry type. For example, in the
case of downlink of a command to transmit from portable extender
device 20 to implanted device 10, the acceptable error rate would
typically be lower than for an uplink of stored electrogram data
from implanted device 10 to portable extender device 20. Similarly,
the performance goal of second priority may differ between two such
telemetry transmission types.
The above disclosure assumes that, during initiation of the telemetry
link, initial communication between the devices may occur using
a telemetry transmission protocol determined to be acceptable for
transmission of control signals between the devices, as verified
by return transmissions, and that this initial communication will
establish the type of telemetry transmission to follow. This protocol
may also be used in conjunction with adjustments of the performance
parameters, as discussed above. However in many cases, feedback
from the receiver to the transmitter is not required to indicate
failure of the telemetry protocol in effect to meet the performance
parameters. In the case of a transmitted electrogram, implanted
device 10 may simply decrease the transmission rate until the minimum
transmission rate is reached and thereafter increase power until
either a specified maximum power level is reached or until a return
transmission from portable extender device 20 indicates an acceptable
error rate.
One of the many classes of RF transmission systems for which the
present invention is believed to be particularly adaptable is referred
to as impulse radio, a technology based upon the pulse position
modulation of very low duty-cycle, ultra-wide-bandwidth RF pulses.
Impulse radio (OR) pulses are processed with data encoding and pseudo-random
noise encoding to smooth the energy in the frequency domain and
provide channelization.
FIG. 3b is a simplified block diagram of communication subsystem
100 associated with portable extender device 20. Communication subsystem
100 is preferably compatible with communication subsystem 44 in
implanted device 10 and as described herein in the above referenced
Goedeke '139 patent. For simplicity in FIG. 3b, however, only transmitter
120, receiver 122 and antenna 124 from communication subsystem 100
are represented in FIG. 3b.
Referring to FIG. 4, portable extender device 20 is a small, easily
carried device consisting of several elements that a nurse may use
during a home health care visit. For ease and portability, extender
device 20 may be equipped with handle 50. Digital pen 52 is used
to enter data by touching pen 52 to screen 54. Software to ease
the task of entering data will be available in the final form of
the present invention. Such software, for example, might have icons
to activate downloading of IMD data, FDA forms, prescription forms,
and audiovisual elements, among others.
Upon activation, the visiting nurse may use microphone 56 that
is the visible portion of an internal cell phone (antenna 60 shown)
that is integrated into the portable extender device 20. Available
software may be used to provide a list of phone numbers that the
nurse may use to contact physicians, other medical experts, druggists,
and her next patient, among others. In a similar fashion, small
video cam lens 58 is the visible portion of an internal video cam
(not shown) that is integrated into portable extender device 20.
Video signals of the nurse, or alternatively, of some portion of
the patient's anatomy, may be transmitted to a remote expert station
(not shown) to facilitate discussion with medical experts available
at that station. Additionally, screen captures of various data sets,
such as an ECG, may be transferred transtelephonically, or by telemetry,
or streaming video. In addition, if the screen capture is deemed
necessary for documentation purposes, the image(s) may be automatically
converted to HTML or PDF format for transmission and/or storage
on a storage disk integrated into portable extender device 20. Since
these components are conventional in their design and operation,
such components will not be described herein in detail, as it is
believed that design and implementation of such components would
be a matter of routine to those of ordinary skill in the art.
FIG. 5 charts the work flow that a visiting nurse or a health care
worker might follow during a normal workday. Before leaving home
for her first visit, the nurse would download daily schedule 70
via IrDA, RF cellular, or satellite link from the service or clinic
for which she works. Using location download 72, the nurse could
use the imbedded GPS system (not shown) to plot the most economical
sequence for her visits scheduled for the particular day. At this
time, the visiting nurse would gather her equipment, portable extender
device, and other materials for her drive to her first patient.
The GPS system would give her directions to her patient's home,
if she was not familiar with the location.
Upon arriving at the patient's home and a general conversation
about the patient's well being, the nurse will activate an icon
on portable extender device 20 (FIG. 3) to download patient data
74. In addition, the nurse will activate separate icons to download
the patient's prescription and treatment plans 74. Since much of
these data are private, the video cam may be used to identify and
verify the nurse's identity and her clearance to access secured
data. Alternatively, other biometrics may be used for confidential
data access, such as fingerprint, voice recognition, iris, or facial
recognition. With the prescription plan displayed, the nurse can
physically check the prescription containers, their contents, and
the number of capsules remaining, along with the expiration date
of the prescription. In this way, the nurse will be able to determine
any action she might have to take such as, for example, contacting
a physician and/or druggist to either refill or renew the prescription.
With the treatment plan displayed on screen 58 of portable extender
device 20 (FIG. 2), she activates an icon to uplink diagnostic data
from IMD 76. Such data might include an ECG tracing, diagnostic
data, current IMD setting, chronic pressure or oxygen signal levels
from a heart failure monitor such as the Medtronic.RTM. Chronicle.TM.,
among others. The heart failure monitor may be as described in U.S.
patent application Ser. No. 09/809,915 "Heart Failure Quick
Look Summary for Patient Management Systems" filed Mar. 16,
2001 and incorporated herein by reference in its entirety. With
these data in hand, the nurse interviews patient 78, to determine
if/when the patient has experienced any untoward symptoms or complaints
related to IMD operation. These complaints, if present, can then
be matched against time-stamped diagnostic data to assist further
in any diagnostic findings.
Interviewing the patient 78, on the other hand, might bring to
light symptoms that are not related to IMD operation. In such cases,
the visiting nurse can turn her attention to acquiring physiologic
data 80, such as blood pressure measurements, eye examination, skin
irritation, among others. With all data in hand, the visiting nurse
will form a complete evaluation of the patient 82, along with any
questions she may wish to discuss with a physician or other medical
expert.
At this juncture, the visiting nurse may wish to contact an expert
86. But, before calling this physician or expert, she must uplink
any data to the network 84. These data must be simultaneously available
to the physician or other expert at the remote location to facilitate
discussion about the patient status and diagnosis. The support expert
88 will advise the nurse of any further steps to be taken. For example,
the nurse may have determined that a prescription may need to be
renewed. The physician expert 88 can write the prescription and
send it directly to the druggist. On the other hand, the expert
to be contacted 88 might be the druggist. The nurse could request
refills of various prescriptions.
If there is no need to contact a remote expert 86, the visiting
nurse might activate a forms icon to fill out any documentation
required for reimbursement or any other need. Upon completion of
any forms or notes, she would end visit 90. After consulting her
daily schedule, the nurse would determine whether this was her last
visit 92. If so, this would mark the end of her workday 96. If not,
she would activate the location download 72 that would give her
directions to her next patient. Upon arriving at her next visit,
she would follow the same workflow routine as discussed hereinabove.
The preceding specific embodiments are illustrative of the practice
of the invention. It is to be understood, therefore, that other
expedients known to those of skill in the art or disclosed herein
may be employed without departing from the invention or the scope
of the appended claim. It is therefore to be understood that the
invention may be practiced otherwise than is specifically described,
without departing from the scope of the present invention. As to
every element, it may be replaced by any one of infinite equivalent
alternatives, only some of which are disclosed in the specification.
|