Patent Application
20110227740
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
The present invention provides a system and method which addresses the needs in the field and overcomes the aforementioned problems with known systems.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Other relatively simple wireless local area networks such as Wi-Fi, Bluetooth, etc. can be used instead, if desired or needed.
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.
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.
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.
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.
These monitors are referred to herein as “bed monitors”, (or, alternatively, as “bed stations”) or “transportation monitors”, respectively.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
The term “hand wash station”, as used herein includes not only stations like station 26 shown in
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.
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.
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.
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.
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.
The dashed line 60 in
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.
As noted above, other known networks also can be used satisfactorily to implement the invention.
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.
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.
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.
Although many suitable microcontrollers are available, one such unit is sold by Silicon Laboratories, Inc. Austin, Tex., Part No. C8051F9XX.
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.
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.
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.
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.
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.
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.
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.
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.
The embodiment will be described first as an addition to the bed monitor 50, as shown in
As shown most clearly in
As shown in
Referring to
Referring now to
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.
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.
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
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.
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.
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.
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.
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.
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.
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.
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.
The components shown in
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.
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.
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.
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
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).
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.
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.
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”.
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.
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.
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 (
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.
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.
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.
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.
Referring again to
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.
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.
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.
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:
The data is sent to the storage location together with a time and date stamp, which is applied automatically by the storage equipment.
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.
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.
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.
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.
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
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.
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).
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.
These features will be described in greater detail below.
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.
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”.
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:
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.
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.
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.
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.
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.
These functions can be achieved by proper programming of the microcontroller of the monitor and the badges in a number of ways.
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.
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.
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.
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.
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.
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.
The correct conditioning of the green LED 56 on the caregiver's badge can provide a strong inducement towards proper hand washing.
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.
If the patient is transferred, for example, from the bed 24 to the wheel chair 48 shown in
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
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.
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.
The ZigBee computer network used in the invention is shown schematically in
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.
Each network should have a coordinator, one or more routers, and one or more end devices.
In the
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
In the network shown in
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.
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.
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.
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.
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.
Following is an example of a sequence of events which might occur for a given health worker.
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).
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.
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.
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.
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.
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.
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.
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.
To further describe the invention and enable those skilled in the art to make and use the system, the following example, with reference to
With reference to
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.
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.
Referring now to
Assuming that the badge at 404 determines that the wake up station is a hand wash station, then, reference is now made to
Referring now to
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.
Referring now to
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.
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.
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.
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.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US09/62493 | 10/29/2009 | WO | 00 | 5/12/2011 |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12269595 | Nov 2008 | US |
| Child | 13128904 | US |
