U.S. patent application number 13/128904 was filed with the patent office on 2011-09-22 for personnel location and monitoring system and method for enclosed facilities.
This patent application is currently assigned to XHALE, INC.. Invention is credited to Henry Wohltjen.
Application Number | 20110227740 13/128904 |
Document ID | / |
Family ID | 41785643 |
Filed Date | 2011-09-22 |
United States Patent
Application |
20110227740 |
Kind Code |
A1 |
Wohltjen; Henry |
September 22, 2011 |
PERSONNEL LOCATION AND MONITORING SYSTEM AND METHOD FOR ENCLOSED
FACILITIES
Abstract
A wireless time-of-flight distance measurement device a motion
detector is used at each of a plurality of stations in a wireless
network in an enclosed facility to accurately locate a
badge-wearing person near the station. The location, badge number
and time of detection are transmitted through the network and
stored in a computer memory. In a healthcare facility, hand washing
detectors are located at some of the stations and caused to
energize a hand wash status indicator light on the badge when the
wearer has washed his or her hands. The light remains "on" for only
a certain length of time, but will be extinguished sooner by a
monitor device near each patient when the healthcare worker leaves
the vicinity of the patient. These events also are transmitted and
stored so that a timed record of each worker's hand washing and
visits to patients is created.
Inventors: |
Wohltjen; Henry; (Bowling
Green, KY) |
Assignee: |
XHALE, INC.
Gainesville
FL
|
Family ID: |
41785643 |
Appl. No.: |
13/128904 |
Filed: |
October 29, 2009 |
PCT Filed: |
October 29, 2009 |
PCT NO: |
PCT/US09/62493 |
371 Date: |
May 12, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12269595 |
Nov 12, 2008 |
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13128904 |
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Current U.S.
Class: |
340/573.1 ;
340/686.6 |
Current CPC
Class: |
G01S 11/16 20130101;
G07C 9/28 20200101; G16H 40/20 20180101; G01S 5/02 20130101; G08B
21/245 20130101; G07C 1/10 20130101 |
Class at
Publication: |
340/573.1 ;
340/686.6 |
International
Class: |
G08B 21/00 20060101
G08B021/00; G08B 23/00 20060101 G08B023/00 |
Claims
1-36. (canceled)
37. A system for locating personnel in an enclosed facility having
a plurality of spaced-apart stations, said system comprising: (a) a
separate indicator badge or tag for each of said personnel; (b) at
least one detector or monitor for detecting when one of said badges
is located within a predetermined distance from one of said
stations, and for reading information from the detected badge or
tag at said station; (c) each of said detectors or monitors
including first and second wireless transmitters for transmitting
first and second wireless signals, the signals having transmission
velocities different from one another; and (d) a device for
detecting the difference in transmission times between said first
and second signals and indicating when said difference is below a
predetermined value.
38. A system as in claim 37 in which at least one or a combination
of the following features is included: (A) said information
includes the identity of said badge, said system further comprising
equipment for transmitting and storing the identity of said badge,
the identity of the station from which said information is
transmitted, and the time of such transmission; (B) said enclosed
facility comprises either or both of the following features: (i)
has walls and at least some of said stations are separated from one
another by one or more of said walls, said stations being arranged
in a wireless network with transceivers for transmitting signals to
and receiving signals from one another, and to a storage device;
(ii) is selected from the group consisting of a patient care
facility having multiple patient care locations and hand washing
locations, said stations being located in at least some of said
hand wash locations and at least some of said patient care
locations, a medical laboratory, a clean-room manufactory, a food
processing facility, and a facility otherwise requiring frequent
hand washing to retard the distribution of pathogens; (C) wherein
said system includes a hand cleanliness detector at each of a
plurality of said stations for detecting and developing a signal
indicating the hand cleanliness of the person wearing said badge
when it is detected, in which each of said badges has an indicating
device for indicating said hand cleanliness, and a wireless signal
receiver for receiving said signal from said hand cleanliness
detector and enabling said indicating device.
39. A system as in claim 38 in which at least one or a combination
of the following features is included: (A) said indicating device
is selected from the group consisting of a visual indicator; a
vibrator; and a combination of a vibrator and a visual indicator;
(B) each of said badges has a timing device for holding said
indicating device in a selected condition for a pre-determined
length of time; (C) each of said hand cleaning detectors comprises
a device for detecting a hand cleaning material on at least one
hand of the person wearing said badge and in which said material
contains a taggant and each of said cleaning detectors is adapted
to detect airborne samples of said taggant; and (D) said material
is selected from the group consisting of alcohol-based hand
cleaners; antimicrobial soaps; antiseptic hand washes; antiseptic
hand rubs; detergents; soaps; waterless antiseptic agents; and
surgical hand scrubs.
40. A system according to claim 37 for monitoring hand cleanliness
in an enclosed patient care facility having a plurality of spaced
apart stations, said system comprising: (a) an indicator tag worn
by each of said personnel; (b) a detector at each of said stations
for detecting each of said tags when it is located within a
predetermined distance from said detector, and for reading
information from said tag; (c) each of said detectors including
first and second wireless transmitters for transmitting first and
second wireless signals having different transmission velocities;
(d) a device for detecting the difference in transmission times
between said first and second signals and indicating when said
difference is within a predetermined range; (e) a hand cleanliness
detector at each of said stations for detecting airborne taggant
material in hand cleaning material at said station and sending
wireless signals responsive to said taggant detection; and (f) each
of said tags having indicator means for indicating the hand
cleanliness of the wearer of said tag, and including a wireless
receiver for receiving said wireless signals from said hand
cleanliness detector to enable said indicator means.
41. A system as in claim 40 in which one of said transmitters
transmits acoustic signals and the other of said transmitters
transmits electromagnetic signals.
42. A method of locating personnel in an enclosed facility having a
plurality of stations therein, the steps of: (a) locating a
detector at each of said stations for detecting the presence of a
person when said person is within a predetermined distance from
said detector by directing two signals of different velocities
towards said person and measuring the time difference between the
receipts of said signals by said person and comparing said
difference with a predetermined value; and (b) developing and
transmitting to said detector information identifying said
person.
43. A method as in claim 42 including at least one or a combination
of the following features: (A) storing for each person detected the
information received and the time when it is received; and (B)
locating a hand wash detector in at least some of said stations,
said enclosed facility being one requiring frequent hand washing by
personnel to retard the distribution of pathogens.
44. The system according to claim 37 comprising an identity and
hand wash status badge to be displayed on healthcare personnel,
said badge comprising: (a) a display member; (b) a remotely
actuatable visual hand wash status indicator on said display
member; (c) a timing device for holding said indicator "on" for a
first predetermined time period after being turned "on" and then
turning said indicator "off" when said time period expires; and (d)
said timing device being remotely actuatable to enable it to
selectively hold said indicator "on" for a shorter length of time
than said first time period.
45. The system according to claim 44 wherein said badge comprises
at least one or a combination of the following features: (A) a
time-of-flight detector for detecting the difference in arrival
times of two signals of different velocities sent from a
measurement station and sending an identification signal when said
difference is below a predetermined level; (B) a vibrator for
vibrating selectively when said indicator is "off"; and (C) a
wireless transceiver for transmitting badge identification and
status indicator information in response to the receipt of signals
from which the location of said badge within a predetermined
distance from a monitor station can be determined in which said
transceiver is adapted to transmit said information at different
predetermined distances from said monitor station in response to
the receipt of different wireless signals received from said
monitor station.
46. The system according to claim 37 which is a healthcare facility
personnel locator and monitor system comprising: (a) a plurality of
tags or indicator badges for carrying by personnel present in said
facility, each of said tags or indicator badges being responsive to
wireless signals from one of said monitor or detector units to
transmit identification signals identifying one of said personnel
associated with said tag or indicator badge; (b) a plurality of
monitor or detector units, each mounted on or near one of a
plurality of patient support structures in said facility; (c) each
of said monitor or detector units having equipment for sending
ranging signals to said tags or indicator badges; (d) a further
device responsive to said ranging signals for determining whether
the distance of each tag or indicator badge from said monitor or
detector unit is within a predetermined distance; and (e) said
monitor or detector equipment being adapted to receive said
identification signals from one of said tags or indicator badges
which is determined to be within said predetermined distance from
said monitor or detector unit, and for transmitting a corresponding
identification signal to another device for storage together with
the time of detection.
47. The system as in claim 46 in which said tag or indicator badge
includes an indicator for indicating the hand wash status of the
carrier of said tag or indicator badge, and said tag or indicator
badge includes a transmitter for transmitting to said monitor or
detector a signal indicating said hand wash status, and in which
said equipment in said monitor or detector is adapted to transmit a
signal corresponding to said hand wash status signal to said other
device for storage.
48. A system as in claim 46 in which at least one or a combination
of the following features is included: (A) the indicator included
in said tag or indicator badge has an "on" condition to indicate
"hands washed" status, includes a holding device for holding said
indicator in the "on" condition for a predetermined time after the
carrier of said tag has washed his or her hands, and further
includes a second holding device responsive to signals from said
monitor for holding said indicator in the "on" condition for as
long as said tag remains within said predetermined distance from
said monitor; (B) said system includes at least one or a
combination of the following features: (a) a device for turning
said indicator off when the indicator is in a condition indicating
"hands washed" status and when said tag has been moved beyond said
predetermined distance from said monitor: (b) in which said second
holding device is responsive to turn off said indicator, to the
simultaneous cessation of receipt of pulsed signals for said
pre-determined length of time and the movement of said tag to a
distance greater than said predetermined distance from said
monitor; (C) said ranging signals comprise first and second
wireless signals of different transmission velocities, said system
including a device for measuring the difference between the time of
flight of said wireless signals and determining when said
difference falls below a predetermined minimum in which said
monitor is set to repetitively send pulsed signals at regular time
intervals, and said second holding device is adapted to start a
timing function upon the receipt of each of said pulsed signals and
turn said indicator off when said pulsed signals have ceased to be
received for a predetermined length of time; (D) said equipment in
said monitor is adapted to transmit to said other device for
storage information indicating that said indicator has been turned
off, and the time of that occurrence; (E) said system includes one
or more of said monitor units at a hand washing station, and a hand
washing detector for detecting a hand washing procedure by the
carrier of said tag, and for energizing said indicator on said tag,
said monitor units being associated with one another in a wireless
network through which information is transmitted to said device for
storage; (F) each of said monitor broadcasts its unique
identification signal, and each of said tags stores that signal,
compares it with a prior signal received from another monitor, and
turns off the indicator on said tag if the compared signals do not
match; and (G) said system includes a motion detector located
adjacent each of said patient support structures for enabling said
equipment for sending said ranging signals only when said motion
detector detects motion by a person within an area adjacent said
patient support structure, including the step of holding said
indicator in an activated condition while said wearer is in said
near vicinity of said patient.
49. A system as in claim 48 in which said monitor unit includes a
transfer device for selectively transferring information regarding
the support structure from whose monitor unit information is to be
transferred to a different one of said support structures to
facilitate maintenance of monitoring when a patient is transferred
from one to another of said support structures, or where said
monitoring is conducted by a monitor physically associated with the
patient such that said monitor moves with said patient when said
patient moves.
50. A method according to claim 42 which comprises controlling an
indicator on a tag or indicator badge worn by a healthcare worker
in a healthcare facility, activating said indicator for a given
time period after the completing of a hand washing procedure by the
wearer of said tag, and de-activating said indicator whenever said
wearer of said tag leaves the near vicinity of a patient in said
facility.
51. A system according to claim 37 which is a healthcare facility
personnel locator and monitor system comprising; (a) a plurality of
monitor units, each mounted on or near one of a plurality of
stations in said facility; (b) a plurality of tags each carried by
one of the personnel present in said facility, each of said tags
being responsive to wireless signals from one of said monitor units
to transmit identification signals identifying one of said
personnel associated with said tag; (c) each of said monitor units
having equipment for sending interrogation signals to said tags;
(d) a motion detector responsive to the detection of the motion of
a person adjacent said station; and (e) said monitor equipment
being adapted to receive said identification signals from one of
said tags which is determined to be within the range of said motion
detector, and for transmitting a corresponding identification
signal to another device for storage together with the time of
detection in which at least one or a combination of the following
features is included: (A) said tag includes an indicator for
indicating the hand wash status of the carrier of said tag, and
said tag includes a transmitter for transmitting to said monitor a
signal indicating said hand wash status, and in which said
equipment in said monitor is adapted to transmit a signal
corresponding to said hand wash status signal to said other device
for storage; and (B) in which said equipment sends said
interrogation signals repeatedly at timed intervals after being
started by said motion detector and until no motion has been
detected for a pre-determined length of time.
Description
FIELD OF THE INVENTION
[0001] This invention relates to the location and monitoring of
personnel in an enclosed facility. The invention also relates to
the monitoring and control of hand washing by personnel in
healthcare facilities and the like.
BACKGROUND OF THE INVENTION
[0002] In many enclosed facilities, it is highly desirable or
necessary to locate the positions of various personnel in the
facility at various times of the day. This can be useful or
necessary for purposes of monitoring the movement of people in
secure facilities to make certain that they are not moving into or
out of areas without authorization, to provide a record of movement
by healthcare workers in hospitals, clinics and the like, and to
determine when each person enters or leaves the facility.
[0003] In particular, in hospitals, it is highly desirable to have
a stored record of the location of each healthcare worker in the
hospital throughout the working day. This can provide valuable
records tending to document healthcare treatment of specific
patients at specific times, and other valuable information.
[0004] It also is desired to detect and record information
indicating the hand wash status of each health-care worker at any
time during a work day, as well as the location of the worker when
the hand wash status is determined.
[0005] An object of the invention is to provide a stored record of
the hand washing activities of each worker in a healthcare facility
over a given period of time, to assist in the encouragement of the
healthcare workers to wash their hands as frequently as necessary
to minimize the spread of infections to patients within the
facilities, and to provide records establishing the degree of
compliance of each healthcare worker with regulations governing
such activities.
[0006] The invention can be used in various facilities such as, but
not limited to, a patient care facility, a medical laboratory, a
clean-room manufactory, food handling facilities, and any facility
otherwise requiring frequent handwashing to retard the distribution
of pathogens or other unwanted particles or microorganisms.
[0007] The need for regular, frequent hand washing in healthcare
facilities is very important. It has been established that the
failure of medical personnel to wash their hands frequently enough
leads to many infections of patients in the facilities with
diseases that they did not have previously (so-called nosocomial
infections). Annually, this causes over 100,000 patient deaths and
many serious new infections, often with drug resistant organisms,
requiring substantial time, expense and suffering by the
patients.
[0008] The cost to hospitals of nosocomial infections is very
large. Insurance providers have recently refuse to compensate
hospitals for any expenses caused by such infections, as well
prohibiting them from passing these costs on to patients. As a
result, hospitals suffer severe financial losses from such
occurrences.
[0009] As a result, stringent hand washing regulations have been
enacted by professional stakeholder organizations and government
agencies. These regulations specify, for example, that the hands
must be washed both before and after contact with each patient.
Although healthcare workers, including doctors, nurses and other
personnel, have been warned and instructed in the requirements for
hand washing, the degree of compliance often is mediocre to poor.
As a result, infection rates attributable to inadequate hand wash
compliance in hospitals and other healthcare facilities are
unacceptably high.
[0010] Various systems and methods have been proposed in the past
for preparing hand wash status records of medical personnel in
hospitals and other healthcare facilities. In such proposals, RF
(radio-frequency) or other signaling is used in connection with
badges worn by healthcare personnel. However, such prior systems
are believed to be deficient and are not believed to be in
widespread use.
[0011] Another problem in healthcare facilities is the monitoring
of the visits of the personnel to specific patients, and the hand
wash status of such personnel before, during and after each such
visit. Records of such visits and the hand wash status of the
healthcare worker would tend to substantiate the level of care and
the hand cleanliness of caregivers for the patient at any given
time. Such records would be useful in determining insurance claims
and in regulatory inquiries.
[0012] A further problem is that the accuracy and reliability of
techniques and devices for monitoring hand wash status by
healthcare personnel need improvement so that the need for hand
washing is indicated reliably and can be used by the healthcare
personnel themselves, as well as patients and others, to reliably
indicate the need for the hands to be washed.
[0013] Another problem with which this invention is concerned is
the location of patients who are moved from their beds to another
location in the healthcare facility, and the monitoring of
caregiver contact with those patients.
[0014] The present invention provides a system and method which
addresses the needs in the field and overcomes the aforementioned
problems with known systems.
SUMMARY OF THE INVENTION
[0015] The present invention provides a system which facilitates
precise location of individuals in a facility and which correlates
the location of such individuals with proximate contact with other
individuals (patients in a hospital, other healthcare facilities;
skilled nursing facilities, assisted living facilities, nursing
homes, for example), and the status of the individual's hand wash
compliance status at the time and location of such proximate
contact with other individuals. It will be appreciated that while
the present system is exemplified with reference principally to a
hospital environment, other environments, including but not limited
to other healthcare environments, food handling environments,
computer clean room and other manufacturing environments, may
likewise benefit from implementation of various embodiments of the
systems and methods disclosed and described herein.
[0016] Accordingly, it is an object of the present invention to
provide an accurate and reliable enclosed facility personnel
location system and method, and a healthcare facility personnel
location and hand wash monitoring system and method which
alleviates or corrects the above-described problems.
[0017] Specifically, it is an object to provide a wireless system
and method which is extremely robust and error-free in detecting
the whereabouts of personnel, and hand wash status of medical or
other personnel, in an enclosed facility.
[0018] It is another object of the invention to provide such a
system and method which detects and records when each healthcare
worker washes his or her hands, when each such worker comes in
close proximity to a patient, and gives to all an indication of the
hand wash status of the worker.
[0019] It is another object of the invention to provide a system
which records such information automatically as the personnel and
patients move within the facility, and provides a stored record
which is retrievable and from which compliance records can be
prepared, for use in proof of compliance and treatment visits to
patients, and other relevant information for such personnel.
[0020] It is a further object to provide such systems and methods
which are wireless, relatively simple and low cost, reliable in
operation, have very low power requirements and long battery life,
and require relatively low maintenance and are largely
trouble-free.
[0021] In accordance with the present invention, the foregoing
objects are met by the provision of a system and method for
locating personnel in an enclosed facility having a plurality of
spaced-apart stations, in which an indicator tag or badge is
carried by each of the personnel.
[0022] Equipment is provided at each station to determine when each
tag is within a predetermined distance from the station, and to
record the number of the tag and time of the event.
[0023] This is done, preferably, by transmitting first and second
wireless signals between the station and the tag. Preferably, the
signals have significantly different transmission velocities. One
signal preferably is an electromagnetic signal, such as a RF
signal, and the other is, preferably, an ultrasonic signal. The
difference in the transmission times of the signals is measured,
and when that difference is below a predetermined level, the
location and tag number are recorded by sending the information
through a network to storage, where it is stored together with the
time and date on which the record is stored.
[0024] In accordance with another feature of the invention, the
various stations within the facility are associated with one
another in a wireless network e.g. a "ZigBee" network, which is
very simple and inexpensive to build and maintain. Preferably the
data is encrypted for secure transmission. Thus, there is created a
useable record for all of the personnel present in the facility
over a given time period.
[0025] Other relatively simple wireless local area networks such as
Wi-Fi, Bluetooth, etc. can be used instead, if desired or
needed.
[0026] When used in a healthcare facility, such as a hospital, each
identification tag or badge is worn by an individual associated
with and whose name appears on that tag. The tag also bears means
such as one or more visible LEDs for indicating to all the hand
wash status of the wearer, and, optionally another indicator, such
as a vibratory or auditory signal, to tell the wearer when hand
washing is needed.
[0027] In at least some of the stations within the facility, hand
washing equipment is provided, in addition to the distance
detection equipment described above. At each such hand wash
station, a hand wash detector is provided to detect and indicate
the satisfactory completion of a hand washing operation by the
badge-wearer and to transmit this information to the badge and turn
on the LED. The LED remains lit for a pre-determined time, during
which it is discernable by all to indicate the positive (hands are
clean) hand wash status of the wearer.
[0028] The hand wash detector preferably senses vapors on or
emanating from the hands of an individual upon application to their
hands of an appropriate hand wash composition, or immediately after
he or she has washed their hands with a substance containing a an
appropriate volatile, detectable compound, such as a chemical
taggant, such as alcohol, which may also be bactericidal. However,
other hand washing detectors which are known in the art can be used
instead, if desired. For example, hand washing may be presumed by
monitoring the dispensation at a given hand wash station of an
appropriate hand washing agent when a given healthcare worker is in
sufficient proximity to such a station.
[0029] In accordance with another feature of the invention,
location detectors, preferably of the same general type as those
used at the hand wash stations, are mounted near or onto patient
beds, and on wheelchairs, gurneys, and other internal hospital
transportation and/or patient-supporting devices for detecting the
tag of each person who approaches the patient close enough to touch
the patient or otherwise transmit pathogens to the patient.
[0030] These monitors are referred to herein as "bed monitors",
(or, alternatively, as "bed stations") or "transportation
monitors", respectively.
[0031] Thus, when a healthcare worker approaches to within a
predetermined distance of a patient located in a bed or on another
support, the bed or transportation monitor records the identify of
each individual tag that is detected, the identity of the patient
and the hand wash status of the worker, and transmits this
information through the network to the data storage facilities,
where it is stored together with the date and time of the
transmission.
[0032] When the patient is transferred from his or her bed to a
wheelchair or other conveyance, the information identifying the
patient and the bed location stored in the bed monitor is
transferred to a similar transportation monitor mounted on the
transportation means, which will detect and record close encounters
with other personnel. Alternatively, or in addition, as described
in further detail below, the patient may be provided with a
detector which detects, records and transmits to a central
processing unit and database, each healthcare worker that
approaches the patient. When used in addition to a bed monitor or
transportation monitor, such patient-specific monitors provide
confirmatory data and redundancy to the system in the event that,
say, a bed monitor is malfunctioning.
[0033] As noted above, preferably, each badge or identity tag worn
by personnel in the hospital facility has an indicator LED, such as
a green light, which is lit immediately upon the successful
completion of a hand washing operation. The LED stays lit for a
predetermined length of time, such as ten minutes, at which time
the light is extinguished and the wearer must wash his or her hands
again in order to relight the LED.
[0034] It usually is required that each healthcare worker wash his
or her hands both immediately before and immediately after touching
or coming close to any particular patient. Therefore, an additional
advantageous feature of the invention is to provide means in each
bed monitor and each transportation monitor to hold the green light
on, if it is on when first detected, for as long as the healthcare
worker remains sufficiently close to the particular patient.
Alternatively, or in addition, an LED on the bed monitor may
illuminate to reflect the status of a healthcare worker's hand
hygiene status while that healthcare worker is attending to the
particular patient.
[0035] It also is advantageous to automatically turn the light off
as soon as the healthcare worker moves away from that particular
patient to go elsewhere, even if the time set for the light to go
out (e.g., 10 minutes) has not expired. This will tend to encourage
the healthcare worker to wash his or her hands before approaching
the next patient. This also may comfort the patient who sees the
green light.
[0036] The use of a single indicator light on the identity tag is
not essential to the invention, but is preferred as being
potentially more acceptable to both patients and healthcare workers
than one like those proposed in the past, which shows another light
(usually red) when the time after the previous hand washing has
expired. Furthermore, the single light limits power usage.
Optionally, a vibratory or auditory signal can be used in the tag
to remind the worker of the need for hand washing.
[0037] It is believed that, if the indicator works accurately, it
will allow the patient to reinforce the requirement of hand washing
by the healthcare worker serving the patient, and also will
engender respect for and reliance on the indicator system.
[0038] An alternative is to simply leave the green light on until
the on time expires, regardless of where the worker goes. Although
this is simpler to do, it is less informative to patients and
workers.
[0039] An alternative embodiment of the invention uses a motion
detector, either in addition to the distance measurement device, or
instead of it, to enable the monitor/personnel locator.
[0040] In the bed monitor, the motion detector stops the unit from
emitting "pings" unless the motion of a person at the side of a
patient support (e.g., bed) is detected. This can help reduce
battery drain, and does not depend upon being able to detect a
badge within range.
[0041] In the hand wash monitor/locator, the motion detector will
start the sending of signals to and receiving of signals from the
badge, regardless of whether the badge wearer has turned the unit
on. Thus, the person is located, even if he or she does not attempt
to wash his or her hands.
[0042] The foregoing and other objects and advantages of the
invention will be set forth in or will be apparent from the
following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] FIG. 1 is a broken-away perspective view, partially
schematic, of an enclosed facility such as a hospital, together
with various components of the locating and detection system of the
invention.
[0044] FIG. 2 is a front elevation view of a one embodiment of an
identity tag worn by personnel in the facility shown in FIG. 1.
[0045] FIG. 3 is a schematic diagram illustrating the use of a
monitor at a doorway to detect and record the passage of a person
through the doorway.
[0046] FIG. 4 is schematic block diagram of a location unit and a
hand wash detector/verification unit constructed in accordance with
one embodiment of the invention.
[0047] FIG. 5 is a schematic block diagram of the electrical
components of one embodiment of the identity tag for use according
to this invention shown in FIG. 2.
[0048] FIG. 6 is a schematic diagram of a network for associating
the various monitors and detectors with one another to perform the
functions of the invention.
[0049] FIG. 7 is a top plan view, partially broken away, of a
motion detector for use in one embodiment of the invention.
[0050] FIG. 8 is a front elevation view of the FIG. 7 motion
detector arrangement for use in one embodiment of the
invention.
[0051] FIG. 9 is a side elevation view of the motion detector
arrangement of FIG. 7 for use in one embodiment of the
invention.
[0052] FIG. 10 is a perspective view of a component of the motion
detector element of FIG. 7 for use according to one embodiment of
the invention.
[0053] FIG. 11 provides a process flow diagram showing the steps
involved in the operation of one preferred embodiment of the wash
station implemented according to this invention.
[0054] FIG. 12 provides a process flow diagram showing the steps
involved in the operation of one preferred embodiment of the badge
worn by healthcare or other workers implemented according to this
invention to document and confirm hand wash compliance.
[0055] FIG. 13 provides a process flow diagram showing the steps
involved in the communication between the badge worn by healthcare
and other workers and the hand wash station implemented in a
preferred embodiment according to this invention, to document and
confirm hand wash compliance.
[0056] FIG. 14 provides a process flow diagram showing the steps
involved in the communication between the badge worn by healthcare
and other workers and the patient bed monitor implemented in a
preferred embodiment according to this invention, to document and
confirm hand wash compliance.
[0057] FIG. 15 provides a process flow diagram showing the
operation of a preferred embodiment of the bed monitor implemented
according to this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE
INVENTION
[0058] FIG. 1 shows a broken-away portion 10 of an enclosed
facility, in this case a hospital, in a preferred embodiment of the
invention.
[0059] The hospital is a typical enclosed facility having several
stories, each having a floor 12, vertical walls 14, 16 and 18
forming a hallway 20, and a patient room 22 containing a patient
bed 24.
[0060] In one exemplary embodiment of the invention, it being
understood that variations on the specific configurations described
herein come within the scope of the invention, in the hallway 20 is
a hand wash station 26 and a personal computer 44 at a station 28,
with the computer 44 sitting on a table 46, for use in a network or
otherwise as described below.
[0061] At the hand wash station 26 are two sinks 30 and 32, two
dispensers 34 and 36 of bactericidal soap, for example, or a
waterless hand hygiene composition, such as an alcohol hand rub
composition, for use in washing the hands, and a towel dispenser,
heated air hand dryer or other hand-drying apparatus 38. Where
waterless hand wash agents are provided, it may not be necessary to
provide or use a hand drying apparatus. A personnel locator and
hand wash detector 40 or 42 is located closely adjacent each
dispenser 34 or 36 or both. Alternatively, or in addition, in
another embodiment according to the invention, the units 40 and 42
may be sensors which record the dispensation of hand wash
composition from the dispensers 34 or 36.
[0062] The term "hand wash station", as used herein includes not
only stations like station 26 shown in FIG. 1, but also other
stations which consist of nothing more than a wall-mounted
dispenser of alcohol-containing gel, r foam or liquid, such as
dispensers sold under the PURELL.RTM. trademark and an associated
hand wash detector such as 40. Such dispensers already are used in
this way in many hospitals today. There need not be a wash basin at
the site, as long as a suitable hand cleaner dispenser is available
there.
[0063] Mounted on or near the patient bed 24 is a personnel locator
or "bed monitor" 50. In the hallway is a wheel chair 48 for
transporting patients. The wheel chair 48 is representative of
gurneys and other such transportation devices as well. The wheel
chair 48 has attached to it a personnel locator or "transportation
monitor" 52, which is basically the same as the bed monitor 50.
[0064] The bed 24, the wheelchair 48, and tables all are referred
to herein as "patient support"-structures on which a patient may
sit or lay down.
[0065] The term "transportation monitor" includes monitors for use
in transporting patients, both inside and outside of the hospital
enclosure, such as in ambulances (ground or airborne), etc.
[0066] The bed monitors need not be mounted on the bed or other
patient-supporting surface, and might be mounted to advantage on
the ceiling above a bed, or on a wall near the bed, or wherever it
best detects identity tags reliably. As discussed below,
alternatively, or in addition, the monitor may be associated with
the particular patient, as, for example, in a wrist band or
necklace, badge or any other apparatus which reliably detects
healthcare workers when they are sufficiently proximate the
particular patient and which does not cause discomfort to the
patient or impede in their receipt of medical attention.
[0067] FIG. 2 shows an identity tag or badge 54 which is worn,
preferably, by every worker in the hospital, or at least by all of
those who will or might come in close proximity to patients in the
hospital. In non-hospital environments, similar tags could be worn,
for example, by old-age care workers, by food handling workers, or
by staff employed to work in clean-room facilities.
[0068] The tag 54 includes an indicator light 56, preferably a
green LED, which is visible to others, as well as the wearer, to
indicate the hand wash status of the wearer. In the area 58 is a
prominent display of the name of the healthcare worker to whom the
tag is assigned.
[0069] The dashed line 60 in FIG. 2 schematically represents
electronic circuitry and devices shown in FIG. 5 which are located
in the tag.
[0070] FIG. 3 is an elevation view showing the location of a
monitor 72, like the bed monitor 50, on the ceiling 68 near a
doorway 62 in a wall 64 with door framing 66 and the floor
indicated at 70. The monitor 72 detects the identity tag 54 worn by
each person passing through the doorway, and causes the identity
tag information and hand wash status to be transmitted through the
network and stored.
[0071] The network preferably is an ultra-low power wireless
network, such as a "ZigBee" network, which delivers information
through a gateway to the central computer system of the hospital or
to another data storage device, as it will be described in detail
below.
[0072] As noted above, other known networks also can be used
satisfactorily to implement the invention.
Personnel Locator and Hand Wash Detector
[0073] FIG. 4 is a schematic diagram showing the electrical and
electro-mechanical components of a personnel locator and hand wash
detector unit 40. In a preferred embodiment according to the
invention, each unit 40 includes three separate modules: an,
optionally, removable and, preferably, rechargeable battery pack or
like power handling module 74, such as a lithium battery pack or
direct wall power management and conversion system to provide
electrical power; a personnel location unit 76, and a hand wash
detection unit 78. It will be appreciated that the following
detailed and specific components comprising each of these elements
may be modified in layout, detail or other specifics without
departing from the essence of the invention disclosed herein. For
example, not all elements described are required to be included in
a given embodiment or implementation of the invention. Thus, for
example, LCD display 104 described below, may or may not be part of
a given implementation of the invention, or may or may not be
included in every installation of the personnel location unit 76,
or hand wash detection unit 78. Likewise, as will be explained
below, a motion detector rather than, or in addition to, a
personnel locator, may be included in a particular implementation
or location, without departing from the essence of the invention
disclosed herein.
[0074] In a preferred embodiment, DC power is delivered from the
battery pack 74 to the personnel location unit 76. Alternatively,
if an electrical outlet is at hand, power can be supplied from an
ordinary 120 volt AC outlet and an AC/DC adapter. Then the battery
serves as a back-up in case of power failure.
[0075] An optional solar charging system 80 can be provided. The
unit 80 is well-known. It uses the over-head electrical lighting
and photovoltaic cells to recharge the battery pack and thus
minimizes or eliminates the chore of recharging the batteries.
[0076] In a preferred embodiment, the personnel locator unit 76
comprises a microcontroller 82, which includes a CPU, RAM, ROM,
etc. and which is programmed so as to perform the functions to be
described below.
[0077] Although many suitable microcontrollers are available, one
such unit is sold by Silicon Laboratories, Inc. Austin, Tex., Part
No. C8051F9XX.
[0078] The locator unit 76 also includes a conventional network
transceiver unit 84 with an antenna 86 for transmitting and
receiving electromagnetic signals, such as RF signals, using, for
example, the IEEE 802.15.4 protocol used by a ZigBee network. The
transceiver 84 is connected to the microcontroller 82 through SPI
port 98.
[0079] A second transceiver 90 also is provided and connected to
the microcontroller 82 through serial port 100 to send and receive
electromagnetic signals, such as RF signals, through an antenna 92
to and from the badges or tags 54 worn by the personnel. In
particular implementations, depending on the type of
electromagnetic signal used, there may be the need to modify
elements 86, 84, 90 and 92, such that, for example, if instead of
RF electromagnetic signals, infrared signals (IR) are used, then,
in that case, these elements would need to constitute IR LEDs to
transmit and IR photodiodes to receive IR signals. Those skilled in
the art will appreciate and understand the particular modifications
required to these elements to achieve equivalent function to the RF
embodiment represented in this example depending on the particular
electromagnetic (EM) transmission and reception variations used in
a particular implementation of the invention. The first EM, such as
RF, signal sent preferably contains a unique signal identifying the
station from which it is issued.
[0080] Also provided is an ultrasonic pulse generator 94 which
sends ultrasonic pulses through an acoustic transmitter 96 to be
received by receiving equipment in the tag or badge 54. The
ultrasonic generator, for example, may comprise a transducer made
by Kobitone Audio Company, P/N 255-400SST12ROX, which generates
pulses at a frequency of approximately 40,000 Hertz. However, other
frequencies and other transducers can be used instead.
[0081] LED 102, preferably colored, is provided to be lit whenever
wireless contact has been made with a badge that is within range;
that is, one which is within a predetermined, preferably
programmable, (depending on the needs of a particular installation
and a particular situation of a locator unit 76), distance from the
locator unit 76.
[0082] LCD display 104 is provided in order to display the
identifying number assigned to the particular tag or badge which
has come into range of the given locator unit 76. Alternatively, or
in addition to detection of the identifying information from a
given tag, the system may include a biometric identification
system, such as, for example, a retinal scanner, facial
recognitions software or a fingerprint reader or the like to
provide a means for positive identification of a given person
performing a hand wash procedure at a particular location at a
particular time.
[0083] A power management subsystem 88 is desirably provided which
receives power from the battery pack 74 and delivers a sample of
the battery voltage to the microcontroller through an ADC port 106,
for the purpose of detecting low battery conditions.
[0084] The subsystem 88 also receives a "hand sense" signal over
line 112 from an ultra low-power sensor, such as a photo detector
110, which serves to turn on the personnel locator 76 and the hand
wash detector 78.
Motion Sensor Embodiments
[0085] In further embodiments of the invention, a motion sensor is
used at each hand wash station in addition to or instead of a
distance measuring device. These embodiments are illustrated in
FIGS. 4 and 7-10 of the drawings.
[0086] The embodiment will be described first as an addition to the
bed monitor 50, as shown in FIGS. 7-10. The bed monitor 50 is shown
in FIGS. 7-10 mounted on a vertical support frame 192 which extends
upwardly from the rear of the bed 24 to a position above the
upraised head portion 186 and horizontal portion 188 of the bed.
The side rails of the bed are shown at 184, and the bed rests on
the floor 190 of a hospital or other healthcare facility. A pillow
194 is shown in FIG. 8.
[0087] As shown most clearly in FIG. 10, a motion detector sensor
180 is mounted on the outside of the housing of the monitor unit
50. A horizontal plate or like shielding means 182 is attached at a
position underneath the sensor 180.
[0088] As shown in FIG. 8, the plate 182 is dimensioned and shaped
so as to form a shield to prevent the sensor 180 from sensing the
motion of the patient on the bed, and forming detector area limits
196 and 198 to confine the motion detection function to persons at
the sides of the bed 24.
[0089] Referring to FIG. 9, preferably, the motion detector has a
range 200 which does not extend significantly beyond the foot of
the bed to thereby avoid detecting the motion of persons merely
passing by.
[0090] Referring now to FIG. 4, the motion detector 110 is
electrically connected to the power management subsystem 88 to turn
on the function of sending sonic signals or "pings" when motion is
detected. The microcontroller 82 is programmed to start the sending
of pings when it has had no response from a badge for a
predetermined number of pings, and has detected no badge within the
range of the distance measurement equipment, and also detects no
signal from the motion detector 110.
[0091] This function is effective to turn off the pinging function
when personnel beside the bed have moved out of range of the
monitor unit. This tends to save battery power by preventing the
ranging signals from being transmitted when healthcare personnel
are not present and moving.
[0092] If desired, the motion detector device can be substituted
for the distance measuring device of the invention, where it is
deemed acceptable, despite the lower accuracy this would entail in
determining the distance of the personnel from the motion
detector.
[0093] When the motion detector is used, in addition to or instead
of the distance measurement device, at a hand wash station, such as
the unit 40 shown in FIG. 4, the unit 76 is turned on by the motion
detector instead of the photosensor 110. This means that the badge
information and other information are sensed and transmitted at the
station through the network for recording, regardless of whether
the person attempts to wash his or her hands at the station. This
can have the advantage of confirming the location of a given person
at a hand wash station at a particular time of day, even though the
person does not wash his or her hands.
[0094] Although a variety of types of motion sensors can be used,
an IR radiometer type, such as those widely available from
Panasonic and others, is believed to be suitable. Although the use
of the shield plate 182 is shown, the motion detector sensor itself
can be adjusted to exclude the bed 24 from its field of view, if
preferred.
[0095] If the motion detector is used in addition to the distance
measuring equipment, the monitor unit 76 will respond only to the
badge which is within the precise distance measurement of the
monitor unit, regardless of motion detected beyond that range. In a
preferred embodiment according to this invention, however, it is
the logic circuitry in the badge which controls all decisions, as
further described herein below.
Hand Wash Detector
[0096] In a preferred embodiment according to this invention, the
hand wash detector unit 78 utilizes some of the principles of hand
wash detection disclosed in U.S. patent application Ser. No.
11/760,100, filed Jun. 8, 2007 and entitled " Hand washing
Compliance Detection System", published as US2008-0303658, and the
related subsequent PCT patent application PCT/US08/066329,
published as W02008/154494, published on 18 Dec. 2008. The
disclosure of those published patent applications is hereby
incorporated herein by reference. It will be appreciated, however,
based on the present disclosure, that in alternate embodiments
according to this invention, positive confirmation of hand wash
compliance may be achieved by other means known in the art. For
example, it is known to apply a marker substance to the hands when
a person required to comply with hand wash compliance policies
washes their hands. Only upon use of appropriate hand wash
procedures is the marker substance removed from the hands, and the
absence of such a marker (that is, essentially the opposite of the
methodology described below), on the hands taken as confirmation of
compliance. Such methodology is less preferred than that disclosed
below because, in the event that a healthcare worker were, for
example, to simply not wash their hands at all, the marker
substance would never be applied to their hands and thus, the
absence of the marker would not be proof-positive that they had
washed their hands. In addition, there may be significant
resistance in various professions or locations to having a
detectable marker which must be washed off the hands applied to the
hands in the first place.
[0097] Thus, in a preferred embodiment according to this invention,
the unit 78 operates to detect vapors emanating from a person's
hands upon application of an appropriate hand wash composition to
the hands, or during or immediately after the person has washed his
or her hands with a cleaning substance including a "taggant" or
"marker" material such as alcohol, (or any other taggant as
disclosed in the referenced and incorporated patent publications
noted above, including but not limited to, for example, GRAS
compounds; volatile, detectable compounds, such as isopropyl
alcohol, ethanol, n-propyl alcohol, combinations thereof and the
like), some of which are common bactericidal constituents of hand
cleaning materials used in hospitals, while others are added for
fragrance, or formulation or the like. The cleaning materials
include, for example, alcohol-based hand cleaners; antimicrobial
soaps; antiseptic hand washes; antiseptic hand rubs; detergents;
soaps; waterless antiseptic agents; and surgical hand scrubs. Where
alcohol is used as the taggant, it may be preferable for the
composition to comprise at least about 5% or 10% or 20% or 30% or
40% or 50% or 60% or 70% or 80% or 90% or even as much as 95%
ethanol, isopropanol, n-propanol, or any combination of these
compounds, or any intermediate concentration of these
compounds.
[0098] During or after the person has washed his or her hands using
alcohol- or other taggant-containing soap or other materials,
released (either automatically or by mechanical action, which
release itself may additionally be monitored and stored according
to this invention as evidence or as additional evidence of hand
wash compliance) from the dispenser 34 or 36, the person presents
his or her hands close to a sensor, such as a photosensor 110.
Ideally, the person does not make physical contact with the
apparatus (thus avoiding recontamination of the recently cleaned
hands) in order to have the sensor measure the presence of the
volatile, detectable compound.
[0099] This photosensor 110 receives battery power over line 116
and sends a signal over a line 112 to the power management
subsystem 88 that turns on the other subsystems. The
microcontroller 82 turns on a small fan 120 through a signal
received over a line 118, and energizes a vapor sensor 111 which is
specifically selected to sense a particular volatile, detectable
compound, antiseptic agent, or taggant included in the hand wash
composition which is then found in the vapor emanating from the
hands of the user.
[0100] The activation of the photosensor 110 starts the operation
of the personnel locator 76, as it will be described in greater
detail below. Alternatively, as also disclosed in detail above, if
less precision is required, a motion detector can be used for this
purpose, alone or in combination with the operation of the
personnel locator 76.
[0101] Also, in one embodiment according to the invention, an
illuminating LED 113 is lit to provide, preferably, white light to
illuminate the hands of the person presenting them. In a preferred
embodiment according to this invention, the person presenting their
hands does not make physical contact with or insert their hands
into the detector, but rather, merely holds their hands up to the
detector. Air in front of the detector is actively drawn into the
detector (as further described below) permitting the sensor
included in the detector to measure volatiles emanating from the
hands that are presented in proximity to the detector.
[0102] The components shown in FIG. 4 are housed in a housing 126.
The fan 122 pulls air out of the housing 126 and ejects it in the
direction indicated by arrows 122, and draws in room air, including
alcohol vapor or other taggant containing vapor from the hands of
the user, in the direction indicated by arrows 124 to be sensed by
the vapour sensor 111.
[0103] After a short period of time, preferably on the order of
less than a minute, or less than 50 seconds, or 40 seconds, or 30
seconds, or 20 seconds or 10 seconds, or 5 seconds or even, most
preferably only a few seconds, or any intermediate time period,
when the vapor sensor detects the alcohol or other taggant in the
vapor, it sends a signal to the microcontroller 82 through an ADC
port 108. This causes the badge transceiver 90 to send an EM
signal, such as an RF or IR signal, to the badge to light the green
indicator light 56. Also, LED 128, visible from outside of the unit
78, lights to verify that a proper handwashing operation has been
detected.
[0104] The vapor sensor 111 can be any of a wide variety of known
chemical detectors, such as those described in the above identified
and herein incorporated by reference co-pending U.S. patent
application and published PCT application. However, for the purpose
of the present invention, it is preferred to use an alcohol
detector, which is readily available and relatively inexpensive,
such as the Model SB30 MOS Heat-Activated Chemical Resistor made by
FIS, Inc. of Markham, Ontario Canada. These detectors are widely
used in breathalyzers which are used to detect the concentration of
alcohol in a person's breath. Of course, other alcohol detectors
can be used instead, as desired.
[0105] In an alternate embodiment according to this invention, the
hand wash detector components described above may be miniaturized
and housed on the badge or tag provided to each healthcare worker.
Alternatively, the hand wash detector may be housed in a separate,
but portable, device, issued to each healthcare worker. It will be
appreciated, however, that in general, it is preferred for this
component of the system to be housed at stationary locations
adjacent hand wash stations so that less equipment needs to be
carried around by healthcare workers, multiple hand wash adherent
workers can confirm their hand wash compliance at only a limited
number of strategically placed hand wash detectors, all of which
should reduce costs of implementing the system in any particular
environment.
Badge Electronics
[0106] FIG. 5 shows the electronic circuit 60 contained in each of
the badges or identity tags 54 shown in FIG. 2. It will be
appreciated by those skilled in the art that other arrangements,
layouts, or specifics than the specifics shown in this figure come
within the scope of this invention, provided they perform similar
functions in similar ways.
[0107] At the heart of the circuit 60 is a microcontroller 132,
which can be of the same type or similar to the microcontroller 82
as used in the unit 40 shown in FIG. 4.
[0108] The circuit 60 also includes power management circuitry 162
and a, preferably, rechargeable lithium battery pack 160. Of
course, other types of batteries may be used, such as, for example,
non-rechargeable alkaline batteries, or even photovoltaic charging
and storage systems known in the art or power storage and
provisions systems yet to be developed. Terminals on the badge (not
shown) are provided in order to recharge the batteries in the
badge, (also referred to herein as tag).
[0109] Also provided is an ultra-low power badge transceiver 134,
which is an electromagnetic signal transceiver, such as a RF
transceiver or IR LED/IR photodiode, that communicates with the
locator unit 76 by means of an antenna 136 or like means
appropriate to the type of EM signal being used to receive RF or
other EM ranging signals from the unit 76.
[0110] Also provided is an ultrasonic receiving unit or microphone
138 and sensor circuit 140 for receiving ultrasonic ranging signals
sent from the unit 76. The microphone 138 is, for example, the Part
Number SPMO2OLUDS microphone made by Knowles Electronics, Inc.,
Itasca, Ill., U.S.A.
[0111] Each of the units 134, 140 delivers its output to a pulse
detection circuit 146 or 144 which develops a corresponding output
pulse. The output pulse of the acoustic circuit is shown at 148 and
is called a "stop pulse", and the pulse produced by the EM, (e.g.
RF) receiver is indicated at 150 and is called a "start pulse".
[0112] An optional vibrator 151, of the type used in cellphones or
the like, is connected for use, under certain circumstances, in
warning the wearer that the hand wash status light 56 is "off", (as
determined by the microcontroller 132, to which both the hand wash
status light 56 and the vibrator 151 are connected), and hand
washing is needed. This element 151 may, alternatively, be an
acoustic signal generator, or light, for example, to provide an
audible or visual reminder that hand washing is needed.
Distance Measurement
[0113] Pulses 148 and 150 are derived from the corresponding
ultrasonic and EM (e.g. RF) ranging signals received from the
locator unit 76. The two signals have vastly different transmission
velocities. The EM (e.g. RF) signals travel at a very high
velocity, approaching the speed of light, whereas the ultrasonic
signals travel at the speed of sound in air, which is a much, much
lower velocity. The pulses 148 and 150 are delivered sequentially
to a time-of-flight ("TOF") timing logic circuit 152 which delivers
an output signal to a 16-bit counter 154 formed in the
microcontroller 132. A clock signal of 100 KHZ is delivered to the
counter by a clock circuit 156.
[0114] The timing logic circuit 152 is set to determine the number
of clock pulses between the start pulse 150 and the stop pulse 148.
When that count is less than a predetermined number, which
indicates a predetermined distance of the badge from the unit 76,
an EM (e.g. RF) signal containing the ID of the badge 54 is
delivered by the transceiver 134 through the antenna 136 to the
unit 76 (FIG. 4). The unit 76 then transmits a signal to the badge
circuit 60 to light the LED 56 to acknowledge that the badge is
within range and that a hand wash has been verified upon sensor
111.
[0115] This range can be varied as desired, but for the handwash
unit locators such as the one shown in unit 40, the range can be
set at a relatively short distance such as two and a half feet (0.8
meter) so as to prevent the unwanted detection of other badges that
might be farther away.
[0116] By locating each of the units 40 and 42 near a separate one
of two sinks or other hand hygiene stations (which may be waterless
stations), and separating the two units 40 and 42 relatively far
from one another, the proximity discrimination may be set such that
no more than one person will come close enough at any one time to
the locator unit 76 at a particular station to turn it on. This
will largely prevent or eliminate ambiguous simultaneous
double-detections.
[0117] If necessary, circuitry can be provided to prevent detection
of a second badge before the first one is finished processing.
However, it is envisioned that healthcare personnel will quickly
learn to avoid this without the need for any special circuitry.
[0118] Of course, it may be possible to use a single unit for two
adjacent sinks, since the unit is turned on by a hand presented to
the vapor sensor 111.
[0119] Referring again to FIG. 5, as well as FIG. 4, when the vapor
sensor 111 has detected a high enough vapor level on or emanating
from the hand(s) of the healthcare worker, the microcontroller
causes the badge transceiver 90 to send an EM (e.g. RF) signal
through the antenna 92 to the transceiver 134 of the badge, which
then, by way of the microcontroller 132, energizes a LED driver
circuit 158 which lights the green LED 56 so that the badge
indicates that the wearer has washed his or her hands within the
last several minutes.
[0120] The microcontroller 132 contains a timer, formed by
software, which maintains energization to the driver circuit 158 to
keep the green LED 56 "on" for a predetermined time, such as ten
minutes, as explained above. After the time has lapsed,
microcontroller 132 extinguishes the green LED 56. The LED 56
remains unlit or "off" until relit by another hand washing
detection.
[0121] The microcontroller 132 can be programmed to perform a
different timing function, such as turning the light 56 out after
only a few seconds, rather than 10 minutes, in response to the
receipt of different signals, say pulses a few seconds a part, for
purposes to be explained below.
[0122] The microcontroller 132 can also be programmed to measure a
different distance, in response to the receipt of different input
signals (e.g. pulses of a few seconds apart) for purposes also to
be described below.
Data Transfer
[0123] The personnel locator, when it has received the return
message from the badge, and when the hand wash detector has
finished its work, sends the following data through the ZigBee or
equivalent network to the hospital computer storage server or
another data storage device: [0124] 1. The identity of the locator
unit. [0125] 2. The badge number that has been read. [0126] 3.
Whether a hand washing procedure has been performed by the badge
wearer.
[0127] The data is sent to the storage location together with a
time and date stamp, which is applied automatically by the storage
equipment.
[0128] Therefore, there is stored a history of handwashing for each
badge wearer at any given date, time and location. This record can
be referred to when proving compliance or non-compliance with hand
wash regulations, etc.
[0129] In an alternative embodiment, where it is not desired to
immediately store the detection data in the main memory of the
hospital computer system, time and date data can be added to each
information batch stored in a local computer such as the computer
44 and later down-loaded to the main memory. On-board memory, in
the badge or locator circuitry or both may also be provided for
temporary, permanent or semi-permanent record keeping or for
periodic download to a central database.
[0130] In any event, the time and date of each personnel location
event is stored in memory, preferably without having to transmit
the time and date information in the wireless network, so as to
minimize the data rate required.
[0131] The data stored in the hospital central computer or other
data storage device is then available for processing, for report
generation, including to hospital administration and, if
appropriate, to an external monitoring agency, such as a state or
national hand wash compliance registry.
Bed Monitors
[0132] Each of the units of the "bed monitor" 50 and
"transportation monitor" 52 is structurally and functionally
similar to or the same as that forming the units 74, 76 and,
optionally 80, shown in FIG. 4, with certain modifications.
[0133] One modification is that, rather than being dormant until
the healthcare worker energizes a photosensor by presenting his or
her hand, the bed monitor repeatedly, at preset time intervals,
sends out ranging signals or "pings" until it detects a badge which
is within range.
[0134] The "range" or maximum limit for the distance at which
badges are detected usually will be longer than the corresponding
distance at hand wash stations, maybe 6 feet to 9 or 10 feet, e.g.
(2 to 3 meters).
[0135] In addition, it is preferred that the monitor automatically
extinguishes the green LED when the caregiver leaves the patient to
go elsewhere, and that the monitor holds the green LED "on" for as
long as the caregiver remains near the patient.
[0136] These features will be described in greater detail
below.
[0137] When a "ping" is sent out and a badge is detected within
range by the monitor, the badge identification number and the
condition of the green LED on the badge ("on" or "off") is
transmitted through the ZigBee or equivalent network to the data
storage system, where it is time-stamped, dated, and stored.
[0138] This procedure is repeated for each caregiver who approaches
the same patient within monitor range. The second or further badges
detected with the same "ping" will be ignored and detected by a
later "ping".
[0139] Also, each of the monitors has its own identification number
and that information is transmitted and stored in memory as well.
Therefore, the storage system now contains the following
information: [0140] 1. The badge identification; [0141] 2. The time
and date of entry or approach to a patient in a given location;
[0142] 3. The identification of the station; and [0143] 4. The
status of the hand wash LED worn by the caregiver.
[0144] Therefore, as with the device 40 at the hand wash station,
the presence or location of the person at a given time and date is
recorded, along with that person's hand wash status when the person
arrived at the location.
[0145] Records of the presence of a particular caregiver at the
bedside of a particular patient at a given time and date can be of
substantial value in corroborating disputed claims of treatment
given to the patient. The hand wash status information can
corroborate the hygienic standards of the visit, as well as
providing data for a compliance profile for the caregiver. From
this disclosure, it will be appreciated by the skilled artisan
that, in addition to confirming hand wash compliance, the system,
device and methods of this invention may be utilized to charge-back
to insurance providers and/or to provide record keeping and billing
information to confirm actual time spent with particular patients,
even in a multi-patient environment by a given health-care
provider, including in an environment with many different
health-care workers. It would be a simple matter for the skilled
artisan to implement appropriate data sorting and selection
algorithms for purposes of generating billing records based on the
health-care worker location in relation to given patients,
independent of the hand wash compliance records which may be
separately stored, sorted and analyzed to confirm compliance with
relevant hand wash policies or regulations in a given
environment.
[0146] In addition, it will be appreciated by the skilled artisan
that, in addition to confirming hand wash compliance, the system,
device and methods of this invention may be utilized to monitor,
evaluate and confirm patient acuity, by determining the number of
interactions specific healthcare worker specialists spend with a
particular patient. For instance, hospitals frequently use "acuity
scores" to determine the nursing ratio for patients as well as
assigning the number of other healthcare workers to a particular
patient. With the information obtained from the system, device and
methods of this invention, hospitals and other healthcare providers
(nursing homes, skilled nursing facilities, surgical centers, etc.)
will be able to better match the needs of the individual patient
with available resources. This should lead to improved patient
care, better assignment of healthcare resources, earlier
identification of changing patient acuity and ultimately reduction
in healthcare costs by better allocation of scare resources.
[0147] The frequency of transmission of the ranging signals, or
"pings", can vary from several per second to only one every 15
seconds or more. It is desirable to make the frequency as high as
possible, without creating an excessive power drain on the
batteries in the badge. It is believed that a frequency of one
pulse every 3 or 4 seconds or less is generally adequate for most
installations of the invention, but may be modified at will by, for
example, an appropriately appointed system administrator, depending
on such criteria as the degree of accuracy required, the level of
traffic (personnel coming and going) in a given location, etc.
[0148] In accordance with another feature of the invention, it is
preferred to hold a lighted hand wash LED 56 "on" while the
caregiver wearing the badge is still by a particular patient's
bedside, to prevent possible concern by the patient if the LED goes
"off" while the caregiver is at the bedside, and also to turn the
LED off automatically whenever the caregiver leaves the bedside to
go elsewhere, so as to strongly urge the caregiver to wash his or
her hands immediately, before approaching another patient.
[0149] These functions can be achieved by proper programming of the
microcontroller of the monitor and the badges in a number of
ways.
[0150] For example, when a badge is first detected by a bed
monitor, the monitor sends an identification signal to the badge
and the badge stores it. The repetitive pulses sent by the monitor
enable the short timing function rather than the long (e.g. 10
minute) function of the microcontroller. The shorter time is equal,
for example, to several "ping" pulses. The new timing cycle is
re-started by every successive "ping" received by the badge.
[0151] Thus, the badge LED will stay lit as long as the badge
continues to receive one of at least some predetermined number of
"pings", and will be automatically extinguished when the "pings"
are no longer received due to the caregiver leaving the
bedside.
[0152] As a precaution against prematurely extinguishing a wearer's
green light, the automatic turn-off of the light can be conditioned
upon the wearer moving out of range of the monitor, as well as the
failure to detect "pings" for a time which exceeds a pre-defined
length of time. This will reduce the number of incorrect
extinguishment occurrences, if there are any.
[0153] When the caregiver proceeds to another patient without first
washing their hands, if the indicator light 56 has not been turned
"off" already, the badge will receive the identification signal of
the new bed monitor, compare it with the one stored with the prior
patient, and turn the light off when the two identification signals
do not match. Also, in this case, the vibrator, audible signal
generator or visual signal 151 can be energized to remind the
caregiver to wash their hands.
[0154] If the caregiver subsequently washes his or her hands, the
LED 56 then will turn on again for the full ten minutes, or for as
long as that caregiver remains within range of that particular
patient's bed or other patient specific monitor, unless another
patient is visited sooner.
[0155] The "pings" transmitted from personnel locators at hand wash
stations should differ from those sent by bed or transportation
monitors, because of the different timing function each would
enable. This can be done by varying the pulse rate of the "pings",
or the ultrasonic or EM (e.g. RF) signal frequency, or in other
ways know to those of ordinary the skill in the art.
[0156] The correct conditioning of the green LED 56 on the
caregiver's badge can provide a strong inducement towards proper
hand washing.
[0157] If the patient can recognize the status, he or she can also
remind a caregiver whose LED is "off" and insist that the hands be
washed. This will give added incentive to the caregiver to wash
without being reminded by the patient.
Transportation Monitor
[0158] If the patient is transferred, for example, from the bed 24
to the wheel chair 48 shown in FIG. 1, the information identifying
the patient can be transferred from the bed monitor 50 to the
transportation monitor 52 on the wheel chair. This can be done by
pressing an exterior button 85 (see FIG. 4) which operates the
transceiver 84 so as to transfer the information from the unit 50
to the unit 52.
[0159] In an alternative implementation of this aspect of the
invention, the process of tracking the patient may be made more
automatic if each patient in a given health-care facility is
provided with a patient locator. Every patient in such facilities
typically is provided with an identification tag of some sort,
frequently in the form of non-detachable (without destruction
thereof) wrist tag. Such patient-specific wrist tag, or other
patient associated locator device may be implemented, such that at
any given time at any given location in the health-care facility,
the patient's location is easily defined and recorded via
communication with such patient-specific locators and the other
elements of this invention. In this fashion, it would not even be
necessary for a health-care provided to remember to press the
exterior button, 85, in order for the information relating to the
particular patient to be transferred from the unit 50, for example,
to the unit 52. This would occur seamlessly, by virtue of
appropriate hand-shake sub-routines built into the communication
software. The patient-specific monitor may then operate in a
fashion equivalent to that described above for the bed monitors
with respect to detecting, logging and transmitting information
about healthcare providers who come into sufficient proximity of
the patient to require them to have complied with established hand
wash requirements for patient contact. In this embodiment, the
monitoring is conducted by a monitor physically associated with the
patient such that the monitor moves with the patient when the
patient moves
[0160] Subsequently, the unit 52 works in the same way as unit 50
to indicate patient contact by healthcare workers and cause storage
of the badge identities and times. Storage of the monitor number
does not, in this case, give location.
[0161] When the patient is returned to his or her bed, the
information can be transferred from the unit 52 to the unit 50
again, as described above. The contact of the patient with specific
healthcare workers at specific times, again is transmitted through
the network and stored in computer memory to provide records for
the future.
Computer Network
[0162] The ZigBee computer network used in the invention is shown
schematically in FIG. 6 of the drawings. Because a wireless local
area network can be extremely variable in configuration, FIG. 6 is
only representative of the many different configurations which can
exist. It will further be appreciated that an implementation of the
present invention which includes wired communication between
various elements of the system represented in FIG. 6 would not,
thereby, be outside the scope of the embodiments contemplated for
implementation of this invention.
[0163] ZigBee network technology is well known and components of
the system are standardized. Nonetheless, each separate facility
and each separate local area of a large facility may have a
different network configuration, depending upon such things as wall
locations, equipment locations, etc.
[0164] Each network should have a coordinator, one or more routers,
and one or more end devices.
[0165] In the FIG. 6 network, the network coordinator is indicated
at 164. It serves as one "node" of the network. The dashed line
between various nodes of the network indicate possible paths of
travel of wireless signals.
[0166] Routers 172, 174 and 176 are positioned as needed. The
coordinator 164 is also a router and the coordinator, together with
the units 172, 174 and 176, determine the routing of wireless
signals in the network. The end devices in FIG. 6 include the units
40, 42, 50, 52 and 72, all of which have been described above.
[0167] In the network shown in FIG. 6, wireless signals from the
end devices are routed along the best route available, which is
determined by software used in the system, and delivered to a
gateway device which is, in this case, the PC 44, which also is
shown in FIG. 1.
[0168] The data is delivered from the PC gateway 44 through the
larger network 166 of the hospital or other facility to a bank of
servers 170 where the data is stored and from which it can be
retrieved to prepare various records or reports for patients,
personnel and, if appropriate, external regulatory authorities.
[0169] As noted above, alternatively, the data can be temporarily
stored in the memory of badge 60, the locator 40, the computer 44
or a connected disk file, and then later downloaded to the server
170. If this is done, the data is automatically timed and date
stamped as it is stored in the memory of the computer 44 or other
intermediate data storage.
[0170] The routers 172, 174, and 176 and the coordinator 164 are
powered on all the time so they can "listen" for communications
from the end devices and deliver stored messages, etc. Therefore,
these devices should use house current through regular outlets,
rather than batteries with appropriate power and data backup
systems known in the art.
[0171] Advantageously, the end devices can be stand-alone
battery-operated devices which "sleep" most of the time. This is
true for the hand wash detectors and the personnel locators
adjacent the hand wash location.
EXAMPLES
[0172] Having generally described this invention, including the
best mode for making and using the invention, the following
specific examples are provided to further expand the written
description of the invention, and to ensure that those skilled in
the art are enabled to practice the invention without undue
experimentation. The specifics of the examples provided below are
not intended to be limiting, and variations, equivalents and
non-critical modifications of the specifics included in these
examples should be considered as coming within the scope of the
general disclosure provided herein and the appended claims.
Example 1
A Given Healthcare Worker Visits Two Different Patients in an
Establishment in Which the Invention is Implemented
[0173] Following is an example of a sequence of events which might
occur for a given health worker.
[0174] First, the worker applies an appropriate amount of an
appropriate hand wash composition to his or her hands. This may be
achieved by actuating a dispenser of a composition which has been
tested with the remaining components of this invention to include a
taggant detectable by the sensor used in the implementation. The
taggant may be alcohol included in a soap composition, or in a
waterless hand hygiene composition or it may be any appropriate,
non-toxic detectable volatile compound. Preferred taggants
according to this invention include, but are not limited to, GRAS
compounds, and compounds discussed and disclosed in, for example,
US2008-0303658 and WO2008/154494. Alternatively, the dispenser may
automatically activate upon detecting sufficiently proximate motion
at a motion sensor included in the dispenser, or upon establishment
of communication between a given dispenser and the identity tag of
a given healthcare worker that has approached the dispenser
sufficiently closely to permit such communication to be
established. In yet a further alternative, the dispenser may
dispense an appropriate quantity of a hand wash agent upon reading
an appropriate biometric, such as a retinal scan, facial
recognition software, or fingerprint of the person demanding, by
their presence at the hand wash station, dispensing of hand wash
agent. The dispenser ideally dispenses a pre-determined quantity of
hand wash composition, and therefore taggant, onto the hands of the
worker. The healthcare worker, on application of the hand wash
composition, either immediately presents their hands to the
detector, or washes his or her hands and, in the process or shortly
after completion of the hand washing, presents them to the hand
wash detector which lights the green LED on his or her badge. The
LED is set to automatically turn off after a system administrator
defined pre-determined period of time (e.g. a ten minute time
delay).
[0175] The worker promptly goes to visit a first patient in a bed.
When he/she enters the range of the bed monitor for that bed, the
bed monitor detects his/her badge number and LED condition, and
sends that data, together with the bed identification number
through the network to the central computer system for storage. The
information is time and date-stamped as it passes into the central
computer storage system.
[0176] The healthcare worker either examines the patient, thereby
making physical contact with the patient, or sits by the bedside of
the patient for, say, five minutes, and then gets up to leave to
visit another patient. After the healthcare worker's badge has not
sensed a "ping" from the bed monitor associated with the first
patient for a predetermined length of time, the green LED is
automatically extinguished even though the ten minute (or any other
pre-determined) time period originally set for the badge has not
yet expired.
[0177] Before going to visit the next patient, the healthcare
worker has to again wash his/her hands and submit them to a hand
wash detector which then relights the green LED, and the healthcare
worker can proceed to visit the next patient.
Example 2
A Healthcare Worker That Takes a Break
[0178] As another example, assume that the healthcare worker
described in EXAMPLE 1 is finished seeing patients for the time
being and takes a lunch break of one half hour. If the green light
on the worker's badge was on at the start of the lunch break, it
automatically turns off when the pre-set time, e.g. ten minute time
limit, has been exceeded.
[0179] Before the worker can resume seeing patients, he/she must
again wash his/her hands in order to re-light the green LED. This
is beneficial because, even though the healthcare worker has not
been visiting other patients, his/her hands have been exposed to
areas and surfaces in the hospital or the outside environment which
might bear pathogens, and washing is, therefore, beneficial.
[0180] The record that is stored and prepared in the central
computer system of the hospital will indicate when the last hand
washing occurred before the worker started his/her lunch break, and
will show no patient contact for one half hour while the worker was
on lunch break, and then will show the subsequent hand washing at
the end of the lunch break, before the visit to the next
patient.
[0181] If desired, a bed or transportation monitor can be located
in a contaminated area or area in which there is extra danger of a
caregiver picking up pathogens. The caregiver would be required to
wash hands on leaving.
Example 3
Process Flow for Entire Operaitonal Embodiment of The Invention
[0182] To further describe the invention and enable those skilled
in the art to make and use the system, the following example, with
reference to FIGS. 11-15, provides a detailed process flow
description of one preferred embodiment of the invention. Those
skilled in the art, based on this disclosure, would be easily
enabled without undue experimentation, to implement appropriate
software and hardware configurations and programming, consistent
with the purposes of this invention, to implement the logic flows
described below.
[0183] With reference to FIG. 11, FIG. 11A provides a logic diagram
showing the Hand Wash Station Process Flow 300. Starting at 301,
the system performs an initialization routine on power-up. If, in
the course of the initialization routine, in which a routine
battery check is performed, if the battery level is low, a yellow
LED is illuminated to show this condition, and the process is put
into sleep mode 300A, rather than continuing with the remaining
steps of the process flow shown in FIG. 11. On the other hand, if
there is no low battery condition, then the system proceeds on to a
wake-up routine 301 from the processor sleep mode, which is
activated by the photosensor 110 shown in FIG. 4 sensing the
presence of a user's hand's in sufficient proximity to the detector
to demand initiation of a hand wash compliance detection cycle.
[0184] Once wake-up has occurred, subroutine 303 is initiated, in
which the fan 122 is turned on and, if included, white LED 102 is
illuminated. If a low battery level is detected, the LED 102 is
changed to a yellow color and an indication of low battery level is
sent to LCD 104.
[0185] Once the fan has been activated, sensor subroutine 304 is
initiated, such that A/D signals are compared 305 between the
sensor signal and a reference signal for a set period of time, say
four seconds, to determine if the sensor signal is less than, the
same as, or greater than the reference signal. If less than, then
the logic continues to 308. However, if the sensor signal is
greater than the reference signal, subroutine 306 is entered,
followed by setting the badge indicator LED 56 to a not lit or not
green state, and from there to 309, see below. If the sensor signal
is less than the reference signal at 305, then at 308 the LED is
turned on to indicate that hand washing has been detected. The
infra-red, IR, (or other electromagnetic, such as radiofrequency,
RF) signal is monitored at 309 for a set period of time, say 4
seconds, to detect whether a badge ID in range can be detected,
310, and if no signal is detected, subroutine 311 is entered,
following which the hand wash station is placed into a sleep mode
until a new wake up signal 302 is detected. However, if a badge is
detected in range and successful handshake protocols to establish
communication occur 313, then the station sends an infrared (or
other EM) signal 314, including the handwash station identity, a
cyclic redundancy check value (CRC, a standard computer algorithm
for error correction) along with a command to set the badge LED to
green to show a recent hand wash event or not green, indicating no
recent hand wash event. An infrared or RF pulse initiates an
acoustic pulse, after some delay 315, and this is checked, 316, for
receipt, for example, of a five hexadecimal character information
string including the badge identification information, the hand
wash compliance status of the badge at the time of data
transmission and the in-range status of the badge. If the badge is
not in range or any of the required data is not received, the
system resets to step 309 demanding a further hand wash procedure.
If, however, all of the required information is properly received,
then 317 the green LED on the hand wash station is lit to confirm
that an acceptable hand wash procedure has been achieved, the
information is logged and saved 318 to confirm communication with
the particular badge and worker and the status of the hand wash on
the badge. The data is transmitted, via a Zigbee or like network,
to store the data in a central database, 320, and the system then
resets 321 to initial status to await a new wake-up event.
[0186] Referring now to FIG. 12, which provides a process flow
diagram 400 for the badge implemented according to the invention.
At 401, the badge is switched on, thereby initiating a badge
initialization routine in which the battery voltage A/D is checked
and flagged by illumination of a yellow LED if the battery is low.
If the badge initialization passes, 402, then if the badge detects
an infrared or equivalent, e.g. RF, EM pulse, the badge processor
is woken to check battery voltage, with a yellow LED being enabled
if a low voltage condition is detected. If this check passes, then
403, if an IR, RF or equivalent EM signal is received from the
locator station, the badge determines if the responding station is
a hand wash station or a patient bed monitor, based on the received
station identification code. The badge responds appropriately 404
depending on the type of station detected, such that, if the wake
up station is a hand wash station 405, the logic described for FIG.
13 applies, and if the wake up station is a patient bed monitor,
406, the logic described for FIG. 14 applies. In this fashion, the
badge substantially determines the subsequent system logic. The
initial EM pulse synchronizes all communication in the system,
which is advantageous because if all communications are
synchronized, then the receiver or other elements not needed in
intermediate times may be turned off or placed in sleep modes,
thereby gaining power savings.
[0187] Assuming that the badge at 404 determines that the wake up
station is a hand wash station, then, reference is now made to FIG.
13, which provides a diagram of logic flow for communication
between the badge and a hand wash station 500. The badge turns on
501 the time of flight (TOF) ultrasonic pulse detector. The badge,
on receiving an infrared pulse on the IR receive line, or,
equivalently, an RF or other EM pulses, sets the time at zero; the
time counter is then active until a later arriving ultrasonic
signal is received. The badge then determines, 502, based on the
difference in receipt times for the ultrasonic and EM signals, the
distance of the badge (and thus the personnel carrying the badge)
from the transmitting station 503. In the event that the distance
is greater than a pre-set distance, say two feet, then subroutine
504 initiates to indicate that the badge is not in range and the
processor is placed into sleep mode. On the other hand, if the
distance is less than the pre-set distance, say two feet, then the
subroutine 505 initiates, first confirming that the battery status
is adequate (if not a low battery indicator is illuminated, as
described above), and then 506, the badge transmits badge
identification information, status and a CRC (cyclic redundancy
check, to confirm data and communication integrity), along with the
status of the badge indicator as green or not green. In response, a
command is received from the base station 507 to turn on the green
LED when the handwash procedure has been confirmed, following
which, 508, either a timer clock is initiated for a set period of
time, say ninety seconds, for the green LED to remain illuminated.
Then, 509, the badge remains in a query state until either EM (such
as IR or RF) communication from a bed station (bed monitor) is
initiated 511, in which case the badge-bed station communication
process flow described below in reference to FIG. 14 is initiated,
and if not, the green LED times out 510, which would require the
healthcare worker to re-initiate a hand wash procedure in order to
once again illuminate the green LED to indicate hand wash
compliance.
[0188] Referring now to FIG. 14, which pre-supposes that the badge
has received an IR or other EM communication from a patient bed
station or other patient-specific communicator, there is provided a
process flow diagram 600 showing the communication between the
badge and the patient location communicator. Thus, at 601, the
badge energizes the TOF ultrasonic pulse detector, and awaits an
acoustic pulse, from which, by difference 602, the distance from
the patient station is calculated. The EM pulse detected by the
badge queues the badge to receive acoustic pulses which, when
received, initiates a stop signal, allowing synchronization as
discussed above. A rule of thumb is, for acoustic transmission
times, 1 foot is travelled per millisecond. Thus, if there is a
time delay of 6 milliseconds or less, for example, from the time of
receipt of the EM pulse until the time of receipt of the acoustic
pulse, then the particular badge in question is within the six foot
proximity set for this particular example. Of course, the
discrimination may be modified as needed for a given location or in
a given application of this system. If the calculated distance is
greater than a pre-set distance, say six feet, then the green LED
on the badge times out 604. However, if the distance is less than
the pre-set distance, say six feet, then the battery status is
again checked 605 to ensure proper operation of the badge, and the
status of the LED is queried. If the LED is not illuminated and
showing a green hand wash compliance status, 607, a cross-check is
initiated such that if the bed station has logged a green LED
approach for this worker already within a pre-set time, then the
badge LED blinks green twice 608 to confirm that, in fact, the
worker's hand wash compliance status is verified. If, however, the
bed station has not already logged a green LED compliant status,
then 611, a vibration or equivalent alternate alert is initiated to
alert the worker that they need to wash their hands before
proceeding any closer to or making any contact with the patient to
which they have been detected to be approaching. Any number of
alert signals may be used, including, for example, a visual, an
auditory, or a vibrate signal, to remind the worker to wash their
hands. Preferably, a vibrate signal is used as this is
non-intrusive and provides a discrete reminder to the worker. In
one preferred embodiment, the vibrate reminder cycle is as shown in
the figure, 611, wherein a first short, single vibration is sent,
then, after a short delay, say two seconds, two vibrations are sent
and then after a further delay, if no hand wash event is detected,
three vibrations are sent. At this point, if no hand wash event is
logged, an auditory signal may be initiated and/or a non-compliant
event may be reported to the hand wash compliance system (referred
to as the HyMarks.TM. software), following which the badge is
placed in a sleep mode 614. If, on the other hand, at 606 the green
LED was on, the badge LED is turned off 609 once contact with the
bed station has been established. After a pre-set amount of time,
say six seconds, the badge LED flashes briefly if the badge is
still in range of the bed station. This process continues until a
new hand wash station or patient location is detected.
Alternatively, at 608, if the bed monitor logged a green LED, then
either way, from 608 and 609 the process flows to 610 the badge
completes its handshake with the bed monitor, transmitting an EM
(e.g. an IR or RF) signal including the badge number and the green
LED hand wash compliance status. At 612 the badge will pulse
inhibit for a pre-set period of time, say five seconds, and then go
back to sleep mode 613 pulsing every 1 second. This permits control
of a situation where, for example, a crisis occurs at a particular
patient location, and a large number of HCWs rush to attend to the
patient. A subsequent cacophony of EM pulses might ensue. Thus, per
this aspect of this embodiment of the invention, the one particular
HCW badge identity information is picked up, logged, their hand
wash status is checked, and then the next badge identification is
sequentially recognized. The badge power on and off sequence
involves, in a preferred embodiment, the following steps and
elements: Badge power ON: If the badge power is off and the power
switch is held down for several seconds, the badge will vibrate
three times and the Green LED and Yellow LED will blink
simultaneously. Releasing the power button when vibration sequence
starts and the badge is powered ON.
[0189] Badge power Off: If the badge power is on and the power
switch is held down for several seconds, the badge will vibrate
once and no LEDs will blink. Releasing the power button when the
vibration occurs and the badge is powered off. The badge will not
respond to bed or hand wash stations when in the power off
mode.
[0190] Referring now to FIG. 15, there is provided a process flow
diagram 700 in which the bed station logic and wake-up procedure is
described in detail. Thus, on power-up, the bed monitor or other
patient associated monitoring device initiates an initialization
routine 701, starting from a sleep mode, upon receiving a wake up
signal from the badge sending an EM (e.g. infrared or
radiofrequency or other appropriate EM) pulse which is received by
the bed EM (infrared, RF or other appropriate) receiver 702. The
bed station then transmits its identifying data via its EM (e.g.
infrared) transmitter 703. The bed station further sends an
infrared (acoustic start pulse) after some delay 704, along with an
acoustic pulse. If the badge determines from the acoustic TOF that
it is in range of the bed station then it sends its identifying
data to the bed monitor for subsequent logging and reporting.
[0191] Once the bed station logs an EM (e.g. infrared) receive
signal from the badge 705, the process flow continues to 706.
However, if no such confirmation is logged, then the bed station
resets to a sleep mode 702, to await an appropriate badge
transmitted wake-up signal.
[0192] Once the bed station has been properly woken 705, the bed
station then logs the identification information of any and all
responding badges 706. The bed station logs all such badges in
range for a pre-set amount of time, say one minute 707, and
constructs and transmits a report via the Zigbee or like network
when any new badge enters or leaves the log. To avoid errors, in a
preferred embodiment, the bed station may be programmed to require
two exact duplicate entries before sending such a report via the
network.
[0193] To confirm proper operation, the bed station performs a
battery level check, and if any low battery condition is detected,
the monitor sets a yellow LED signal to illuminate 708. All of
these steps having been completed, the Zigbee report is assembled
709 and the report is transmitted to the central report database
over appropriate communication lines and protocols 710 such as, for
example, a UART buss known in the art. Once completed, the bed
monitor resets all enabled lines back to its initial state, placing
the processor back into a sleep mode 711, thereby readying the bed
processor for a new wake up signal as at 702.
[0194] The above description of the invention is intended to be
illustrative and not limiting. Various changes or modifications in
the embodiments described may occur to those skilled in the art.
These can be made without departing from the spirit or scope of the
invention.
* * * * *