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Embedded System for Hygiene Compliance Monitoring

August 2010
IEEE Transactions on Automation Science and Engineering 7(3):695 - 698

DOI:10.1109/TASE.2010.2044882

Source
IEEE Xplore

Authors:

Veronique M Boscart

Conestoga College

Geoff Fernie

Toronto Rehabilitation Institute

Different approaches to implementation of hygiene compliance monitoring are presented. The architecture and operation of an embedded distributed system for hygiene compliance monitoring are described. The performance of the system does not depend on the number of monitored areas, number of caregivers being monitored, and no network infrastructure is required. Note to Practitioners-The embedded system for hand hygiene monitoring system was designed to be used in healthcare institutions. The main function of the system is to monitor hand hygiene compliance according to the rules (based on the Ministry of Health and Long-Term Care guidelines) implemented as a part of the system software. The main components of the system are wearable electronic monitors, disinfectant dispensers, and monitored zones installed in the areas essential for hand hygiene compliance.

Embedded system for hygiene compliance monitoring. In this distributed architecture, both zone controllers and personal wearable monitors work completely independently without any network or central coordinating unit. The system is easily scalable, its performance does not depend on the number of monitored zones or the number of wearable monitors.

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Block diagram of the wearable dispenser operation in the distributed system. A number of software timers are used to adjust disinfection expiry intervals for different clinical environments. t-time elapsed since the previous detection of the zone; t-elapsed time since last hand hygiene action; t-estimated duration of protection provided by a single hand hygiene event when outside zones; t-time permitted outside a zone before returning without the need for hand hygiene.

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IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING, VOL. 7, NO. 3, JULY 2010 695

Embedded System for Hygiene Compliance Monitoring

Alexander I. Levchenko, Member, IEEE, Graham C. Hufton,

Veronique M. Boscart, and Geoff R. Fernie

Abstract—Different approaches to implementation of hygiene com-

pliance monitoring are presented. The architecture and operation of an

embedded distributed system for hygiene compliance monitoring are de-

scribed. The performance of the system does not depend on the number of

monitored areas, number of caregivers being monitored, and no network

infrastructure is required.

Note to Practitioners—The embedded system for hand hygiene moni-

toring system was designed to be used in healthcare institutions. The main

function of the system is to monitor hand hygiene compliance according to

the rules (based on the Ministry of Health and Long-Term Care guidelines)

implemented as a part of the system software. The main components of

the system are wearable electronic monitors, disinfectant dispensers,

and monitored zones installed in the areas essential for hand hygiene

compliance.

Index Terms—Data acquisition, infrared tracking, intelligent systems,

microcontrollers.

I. INTRODUCTION

Approximately one in ten people admitted to hospitals in Canada ac-

quire a new infection during their stay. Gould et al. [1] report that these

nosocomial infections result in an estimated 8000 deaths per year. In

addition, there is considerable waste of resources and stafﬁng because

of the increased length of stay required. It is evident that this situation

contributes signiﬁcantly to the overall stress on the healthcare system

and increases wait times.

It is estimated that approximately half of these nosocomial infec-

tions are the result of inadequate hand hygiene by healthcare staff.

Unfortunately, published studies have generally found that compliance

with hand hygiene requirements by healthcare workers averages about

40% [2] and that various educational and management interventions

can only improve this to about 50%. Further, sustainability of the im-

provement produced by interventions is a problem.

Pittet et al. [3] provide the most recent authoritative review of evi-

dence that hand hygiene is the primary means to reduce nosocomial in-

fections. This review describes how pathogens are present even on un-

broken skin and on surfaces surrounding the patient. These organisms

are then transferred to healthcare workers hands where they can survive

Manuscript received June 30, 2008; revised January 20, 2009; accepted Feb-

ruary 21, 2010. Date of publication March 29, 2010; date of current version July

02, 2010. This paper was recommended for publication by Associate Editor

A. Colombo and Editor D. Meldrum upon evaluation of the reviewers’ com-

ments. This work was supported in part by the Health Technology Exchange and

the Canadian Institutes of Health Research (ref. # HTX 80047, XHT 83447).

We acknowledge the support of Toronto Rehabilitation Institute who receives

funding under the Provincial Rehabilitation Research Program from the Min-

istry of Health and Long-Term Care in Ontario. The views expressed do not

necessarily reﬂect those of the Ministry. Equipment and space have been funded

with grants from the Canada Foundation for Innovation, Ontario Innovation

Trust and the Ministry of Research and Innovation. Patent applications have

been ﬁled.

A. I. Levchenko, G. C. Hufton, and V. M. Boscart are with the Research and

Development Technology Team, Toronto Rehabilitation Institute, Toronto, ON

M5G 2A2 Canada (e-mail: Levchenko.Alexander@torontorehab.on.ca; Hufton.

Graham@torontorehab.on.ca; Boscart.Veronique@torontorehab.on.ca).

G. R. Fernie is with the TorontoRehabilitation Institute and the Department of

Surgery, University of Toronto, Toronto, ON M5G 2A2 Canada (e-mail: Fernie.

Geoff@torontorehab.on.ca).

Digital Object Identiﬁer 10.1109/TASE.2010.2044882

for hours. The review outlines the evidence that an alcohol-based hand

rub is signiﬁcantly more effective than washing with soap and water

and concludes that experimental studies have all shown that improved

hand hygiene reduces transmission of pathogens.

II. INVESTIGATED HYGIENE COMPLIANCE MONITORING SOLUTIONS

There have been some attempts to improve hand hygiene compliance

through the incorporation of electronic prompting systems in wearable

and stationary alcohol gel dispensers. Kinsella et al. [4] conducted a

study using gel and soap dispensers, equipped with a microcontroller-

based time stamping device, in an intensive care unit to collect data

about soap and gel use for hand-hygiene quality improvement and ed-

ucational initiatives. Unfortunately, this approach has a limited value

as the records of hand cleansing actions are provided unrelated to the

caregiver’s location and activity. Venkatesh et al. [5] and Swoboda et

al. [6] evaluated an electronic prompting system that used light beams

and motion detectors at the threshold of each room in a surgical unit.

The system had visual and voice prompting function instructing the in-

dividuals to wash their hands if they had not done so before entering

or after exiting the room The system could work only with stationary

dispensers, did not record individual performance data and could not

provide a prompting signal in a multipatient environment when a care-

giver moves from one patient to another.

We postulate that in order to be able to estimate hand hygiene

compliance and provide efﬁcient prompting functionality, the system

should have information both on caregiver’s location and hand

cleansing activities. One technical approach that we considered was

to use the hygiene compliance algorithms [7] and control software in

conjunction with commercially available location tracking systems.

In this case, caregivers would have identiﬁcation tags working in

combination with arrays of readers that allow wearers coordinates to

be determined. Depending on the tag’s positional coordinates the host

computer would estimate the probability of contact between patient

and caregiver and would decide when to issue a prompting signal.

For this application, the major requirements for the location tracking

system are the ability to operate in a hard real-time mode providing

guaranteed maximum reaction time and the ability to determine a tag’s

positional coordinates with high accuracy. The user tag should be ac-

tive and it should be small enough to be integrated into a wearable dis-

penser or to be able to communicate with it. It should also be able to

log and process hand cleansing events or to communicate with the host

computer every time a hand cleansing occurs.

Our clinical tests demonstrated that to perform efﬁciently the system

must guarantee a reaction time (time interval between entering the pa-

tient environment and the moment when the prompting signal is issued)

not exceeding one second. The system must also identify that the care-

giver is within the patient area with a 20–30 cm accuracy. To date,

RF-based location tracking solutions [8]–[12] do not meet these re-

quirements. Some vendors of ultra-wideband (UWB) tracking systems

claim that they can achieve about 30 cm accuracy [13] and control mul-

tiple tags simultaneously. Although the UWB technology is advancing,

the main limitation of this approach is considerable capital investments

in infrastructure and hardware. In a complex indoor environment, extra

expensive sensors might be required to improve coverage and provide

accurate tracking [14].

During our development program, we next built a prototype of the

key elements of another approach which used ultrasound ranging sen-

sors. The arrays of programmable ultrasound receivers controlled by

a wireless ZigBee network coordinator were installed to mark the pa-

tient areas. Portable units based on the PIC18F2620 microcontroller

and a CC2420 RF transceiver were conﬁgured as ZigBee™ Reduced

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696 IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING, VOL. 7, NO. 3, JULY 2010

Fig. 1. Embedded system for hygiene compliance monitoring. In this distributed architecture, both zone controllers and personal wearable monitors work com-

pletely independently without any network or central coordinating unit. The system is easily scalable, its performance does not depend on the number of monitored

zones or the number of wearable monitors.

Function Devices (RFD). The ZigBee coordinator constantly polled the

wearable units having ultrasound transmitters. It sent a command to the

wearable unit being located to produce a short ultrasound pulse. Imme-

diately after receiving conﬁrmation from a ZigBee™ RFD device the

coordinator sent a “Listen” strobe to all zone sensors that included the

ID of the wearable unit and the current status of the hand disinfection

status “ﬂags” of this caregiver. If none of the zone sensors detected

anything within a certain time interval (set depending on the size of

controlled zone), the procedure was repeated for the next unit. If any

of the zone sensors detected the presence of a wearable unit it could

provide a prompt to the caregiver if the hand disinfection status ﬂag

was not set to clean. The identity of the wearable unit (a surrogate for

the caregiver’s identity), the times of entering and leaving identiﬁed

patient zones marked by sensors and the times of hand disinfection ac-

tions on the wearable unit were all stored by the coordinator/PC for later

downloading and data analysis. Since the system worked in a polling

mode the number of devices that could be controlled by one central unit

without affecting system performance was limited. The communication

intervals between the RFD and the coordinator were dictated by the re-

quired reaction time and resulted in higher power requirements for the

portable devices. In addition, extra routers were needed to cover areas

larger than the range of ZigBee coordinator increasing complexity of

the system.

III. DEVELOPED ARCHITECTURE:EMBEDDED MONITORING SYSTEM

We subsequently developed an alternative low-cost distributed ar-

chitecture (shown in Fig. 1) which is free from the above mentioned

limitations. In this concept all monitoring and data processing func-

tions are embedded in the personal wearable monitors, which allows

them to operate completely independently without any network infra-

structure and any central control and processing unit.

The patient areas are instrumented with arrays of low intensity in-

frared emitters, constantly transmitting modulated unique patient area

identiﬁers. The main functions of the wearable monitors are to demod-

ulate and decode patient zone identity signals, record the real time of

entering/leaving and codes of visited zones, record the real time of dis-

penser activations, and to provide prompting to perform hand hygiene

when required.

One of the major advantages of this approach is that reaction time of

the system is deﬁned entirely by embedded software and does not de-

pend on the number of units being monitored, their locations, number

of patient areas installed and any network characteristics. The perfor-

mance is not affected when two or more caregivers work simultane-

ously in the same patient area. The cost of the distributed system as

well as the hardware and software requirements is considerably lower

compared to centralized architectures. The wearable monitors are de-

signed so they are not obscured during use to maintain reliable infrared

communication. Each of these units communicates with its wearable

alcohol gel dispenser by a short range RF link so that the dispenser can

be worn or carried in a variety of ways without restriction.

Infrared emitters deﬁning the patient areas are housed in specially

designed conical directional elements (35 15 mm). Symmetrical con-

ical directional elements are used to provide even coverage inside the

zone, while narrow elliptical directional elements are angled toward the

center of the zone to provide a crisp zone perimeter. The directional el-

ements are injection molded white polypropylene with a polished ﬁnish

and are housed inside two-part PVC extrusions in groups of three, with

a total of thirty six emitters deﬁning patient areas (3.8 each) in the

test room. The PVC extrusions housing the directional elements are

prewired for ease of installation and are clipped, screwed or adhered to

the ceiling to create a zone of required shape and size, without inter-

fering with overhead patient lifts and other equipment used inside pa-

tient area. The zone emitters are controlled by a PIC24FJ16GA004 mi-

crocontroller and emit 36.7KHz modulated infrared code that includes

the type and identiﬁcation number of the zone, with each zone being

mately 200 mA.

The zone microcontroller can automatically adjust the intensity of

the infrared signal depending on ambient light to maintain the required

accuracy of the zone boundaries. This function is required only to com-

pensate for signiﬁcant changes of ambient light conditions. In our tests

with the constant signal radiant intensity of 7 mW/sr per emitter, the

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IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING, VOL. 7, NO. 3, JULY 2010 697

Fig. 2. Block diagram of the wearable dispenser operation in the distributed system. A number of software timers are used to adjust disinfection expiry intervals

for different clinical environments. – time elapsed since the previous detection of the zone; – elapsed time since last hand hygiene action; – estimated

duration of protection provided by a single hand hygiene event when outside zones; – time permitted outside a zone before returning without the need for

hand hygiene.

variations of zone boundaries did not exceed 15 cm, with the illumi-

nance of ambient light changing from 30 to 500 lux. Assuming that all

infrared emission is perfectly concentrated inside the zone, the com-

bined irradiance from all emitters inside the patient zone at typical op-

erating ranges is around 0.118 . This is more than 130 times

under ACGIH [15] safety limits for continuous exposure.

The main components of the wearable electronic monitor are

an STM32F102CBT6 ARM Cortex™–M3 based microcontroller,

MICRF211 433.92 MHz receiver, and a PNA4701 infrared detector.

EEPROM emulation algorithms are implemented in software to use

embedded ﬂash memory for the data logging function. A special

protocol with a pulse width modulation encoding pattern has been

developed to provide reliable detection of the zone signal and elim-

inate possibilities of false prompting, with an STM32F102CBT6

decoding zone signals in sleep mode using external interrupts. Each

monitor (dimensions: 50 40 11 mm) is powered by a single AAA

NiMH rechargeable battery, with charging required once a week.

Wearable monitors and portable dispensers work in pairs with each

dispenser which contains a replaceable gel cartridge. Typically, one to

two cartridges are required per shift, depending on the care activities

carried out. Each dispenser is equipped with a PIC16F506 microcon-

troller and a MAX1472 transmitter, with lower than 2 dBm output

power setting, to inform its corresponding monitor about dispenser

activations. The hand disinfection status “ﬂags” of the caregiver are

stored in the wearable monitor so it knows whether the wearer has

recently performed hand hygiene (this time interval can be set in

the software), or whether the wearer’s hands have been disinfected

since the previous patient zone was visited. The data recorded by the

monitors are later downloaded to a PC via a USB interface for further

analysis and reporting.

A simpliﬁed logic diagram illustrating the operation of the monitor

is shown in Fig. 2. The device is in sleep mode most of the time and

wakes up periodically to check the presence of the zone emitters. The

duration of the power saving intervals is controlledby a microcontroller

watchdog timer and deﬁned by the maximum acceptable reaction time

when a caregiver enters the zone. The experiments were conducted in

a four-bed room on a chronic care unit of a larger complex continuing

care hospital. Nine registered nurses, employed on the unit, participated

in the tests. In multiple-bed rooms, a nurse often responds to different

patients in a short time by moving between patient beds. The minimum

distance between two beds in the four-bed room was 120 cm. The reac-

tion time of the monitor was determined experimentally to guarantee

that when a caregiver enters the patient environment, the prompting

signal is issued before any contact with a patient or other objects in-

side the protected area. In our test, this parameter was conﬁgured not

to exceed 800 ms. If the zone is detected the device checks that the

last disinfection occurred not earlier than the disinfection expiry time

outside of the zone which is programmable and may vary for dif-

ferent applications. If disinfection was not performed or the time has

already expired the device prompts the caregiver to activate the dis-

penser. When the monitor leaves the zone its disinfection status ﬂag

remains set to clean for a certain period of time ( ), so the care-

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698 IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING, VOL. 7, NO. 3, JULY 2010

giver is allowed to leave the zone temporarily and come back without

prompting. In our tests, it was initially set at 30 seconds. When care-

givers performed procedures involving complex motion patterns, for

example, transferring a patient to a wheelchair, the monitors periodi-

cally lost communication with the zones for longer than periods

of time, as some procedures require a caregiver to frequently step in and

out of the zone. Nurses performing complex procedures sometimes re-

ported false prompts inside the patient areas, until was adjusted

to 60 seconds. In the system software, variable immediately ex-

pires if, after leaving the patient zone, a caregiver leaves the patient

room, goes to a shared bathroom, or goes to another patient area, as

in a full system conﬁguration all these destinations are controlled by

speciﬁc zone types. This allows the monitors to ﬁlter the events when

communication with a patient zone is lost due to the complex maneu-

vering inside the patient area required by certain procedures. Another

timer implemented in software (not shown in Fig. 2) is used to con-

trol a hand hygiene status ﬂag when the dispenser is activated inside

the patient zone, so that if a caregiver performs hand hygiene inside

the patient zone and then leaves the zone within short programmable

time interval going directly to another patient zone, the system does not

issue a prompting signal when the next zone is entered. If the device de-

tects a zone which is different from the previous one and the dispenser

was not activated between the zones, or within a short programmable

interval before leaving the previous zone, then the disinfection status

ﬂag changes immediately issuing the prompting signal. Time intervals

and other parameters of the monitors are conﬁgured via USB without

changing their software and are adjusted depending on the clinical en-

vironment. Three types of monitored zones are deﬁned for the patient

rooms: entrance zones, individual patient zones, and bathroom zones.

The zones can also be installed in utility rooms, laundries and other

areas where hand hygiene monitoring is required.

The logic described above applies to the patient zones, but is dif-

ferent for entrance and bathroom zones. When an entrance zone is de-

tected and hand hygiene has not been performed within an acceptable

time ( ) the device produces a longer audio signal prompting the

caregiver to perform cleansing after entering the patient room. If the

dispenser is activated just before entering the room and, after entering,

the caregiver goes directly to a patient zone the prompting is not is-

sued. When a caregiver enters a bathroom zone, the wearable monitor

does not produce a prompting signal but it is issued immediately after

exiting the bathroom zone.

Most clinical settings are equipped with a number of wall-mounted

alcohol gel dispensers installed in hallways close to the room entrances.

In our system, each of these wall mounted dispensers has its own small

infrared zone that is used to inform the monitor that its wearer has used

a stationary dispenser. These small zones are inactive most of the time

and transmit only for a few seconds after activation of the stationary

dispenser.

There are obvious privacy issues for the staff since the system can

be used to determine how long caregivers spend with speciﬁc patients,

not just whether they wash their hands. A degree of anonymity can be

provided by not associating the names of individuals with the identity

numbers of the monitors. Nevertheless, together with clinical mem-

bers of our team, we conducted a separate study [16] to evaluate ac-

ceptability of the new technology. Staff agreed that the system would

increase hand hygiene and found it was a convenient approach to re-

mind them about this task, which is often overlooked in the hectic pace

of competing clinical activities. The study demonstrated positive feed-

back from clinicians who felt comfortable with receiving individual

performance information and found the system acceptable with some

caveats.

IV. CONCLUSION

The distributed embedded system has a number of advantages com-

pared to other architectures. Embedding all monitoring and data pro-

cessing functions into the wearable monitors provides guaranteed reac-

tion time and makes the system seamlessly scalable without affecting

performance, with the number of wearable monitors being practically

unlimited. The proposed approach simpliﬁes installation and allows the

wearable devices and monitored zones to be added or removed at run-

time. The zone controllers and wearable monitors work completely in-

dependently without any central control unit and no network infrastruc-

ture is required.

ACKNOWLEDGMENT

The authors wish to acknowledge the contribution of S. Gorski and

other members of hand hygiene project team.

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Using psychological theory to inform methods to optimize the implementation of a hand hygiene intervention

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IMPLEMENT SCI

Background Careful hand hygiene (HH) is the single most important factor in preventing the transmission of infections to patients, but compliance is difficult to achieve and maintain. A lack of understanding of the processes involved in changing staff behaviour may contribute to the failure to achieve success. The purpose of this study was to identify nurses’ and administrators’ perceived barriers and facilitators to current HH practices and the implementation of a new electronic monitoring technology for HH. Methods Ten key informant interviews (three administrators and seven nurses) were conducted to explore barriers and facilitators related to HH and the impact of the new technology on outcomes. The semi structured interviews were based on the Theoretical Domains Framework by Michie et al. and conducted prior to intervention implementation. Data were explored using an inductive qualitative analysis approach. Data between administrators and nurses were compared. Results In 9 of the 12 domains, nurses and administrators differed in their responses. Administrators believed that nurses have insufficient knowledge and skills to perform HH, whereas the nurses were confident they had the required knowledge and skills. Nurses focused on immediate consequences, whereas administrators highlighted long-term outcomes of the system. Nurses concentrated foremost on their personal safety and their families’ safety as a source of motivation to perform HH, whereas administrators identified professional commitment, incentives, and goal setting. Administrators stated that the staff do not have the decision processes in place to judge whether HH is necessary or not. They also highlighted the positive aspects of teams as a social influence, whereas nurses were not interested in group conformity or being compared to others. Nurses described the importance of individual feedback and self-monitoring in order to increase their performance, whereas administrators reported different views. Conclusions This study highlights the benefits of using a structured approach based on psychological theory to inform an implementation plan for a behavior change intervention. This work is an essential step towards systematically identifying factors affecting nurses’ behaviour associated with HH.

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Sep 2018
AM J INFECT CONTROL

Background: Hand hygiene (HH) compliance in health care is usually measured against versions of the World Health Organization's "Your 5 Moments" guidelines using direct observation. Such techniques result in small samples that are influenced by the presence of an observer. This study demonstrates that continuous electronic monitoring of individuals can overcome these limitations. Methods: An electronic real-time prompting system collected HH data on a musculoskeletal rehabilitation unit for 12 weeks between October 2016 and October 2017. Aggregate and professional group scores and the distributions of individuals' performance within groups were analyzed. Soiled utility room exits were monitored and compared with performance at patient rooms. Duration of patient room visits and the number of consecutive missed opportunities were calculated. Results: Overall, 76,130 patient room and 1,448 soiled utility room HH opportunities were recorded from 98 health care professionals. Aggregate unit performance for patient and soiled utility rooms were both 67%, although individual compliance varied greatly. The number of hand wash events that occurred while inside patient rooms increased with longer visits, whereas HH performance at patient room exit decreased. Eighty-three percent of missed HH opportunities occurred as part of a series of missed events, not in isolation. Conclusions: Continuous collection of HH data that includes temporal, spatial, and personnel details provides information on actual HH practices, whereas direct observation or dispenser counts show only aggregate trends.

Effect of electronic real-time prompting on hand hygiene behaviors in health care workers

Article

Full-text available

Mar 2018
AM J INFECT CONTROL

Background: Poor hand hygiene by health care workers is a major cause of nosocomial infections. This research evaluated the ability of an electronic monitoring system with real-time prompting capability to change hand hygiene behaviors. Methods: Handwashing activity was measured by counting dispenser activations on a single nursing unit before, during, and after installation of the system. The effect of changing the prompt duration on hand hygiene performance was determined by a cluster-randomized trial on 3 nursing units with 1 acting as control. Sustainability of performance and participation was observed on 4 nursing units over a year. All staff were eligible to participate. Results: Between June 2015 and December 2016, a total of 459,376 hand hygiene opportunities and 330,740 handwashing events from 511 staff members were recorded. Dispenser activation counts were significantly influenced by use of the system (χ2[3] = 75.76; P < .0001). Hand hygiene performance dropped from 62.61% to 24.94% (odds ratio, 0.36; 95% confidence interval, 0.34-0.38) when the prompting feature was removed. Staff participation had a negative trajectory of -0.72% (P < .001), whereas change in average performance was -0.18% (P < .001) per week for the year. Conclusions: Use of electronic monitoring with real-time prompts of 20 seconds' duration nearly doubles handwashing activity and causes handwashing to occur sooner after entering a patient room. These improvements are sustainable over a year.

Chemical-sensitive graphene modulator with a memory effect for internet-of-things applications

Article

Full-text available

May 2016

Modern internet of things (IoTs) and ubiquitous sensor networks could potentially take advantage of chemically sensitive nanomaterials and nanostructures. However, their heterogeneous integration with other electronic modules on a networked sensor node, such as silicon-based modulators and memories, is inherently challenging because of compatibility and integration issues. Here we report a novel paradigm for sensing modulators: a graphene field-effect transistor device that directly modulates a radio frequency (RF) electrical carrier signal when exposed to chemical agents, with a memory effect in its electrochemical history. We demonstrated the concept and implementation of this graphene-based sensing modulator through a frequency-modulation (FM) experiment conducted in a modulation cycle consisting of alternating phases of air exposure and ethanol or water treatment. In addition, we observed an analog memory effect in terms of the charge neutrality point of the graphene, V cnp, which strongly influences the FM results, and developed a calibration method using electrochemical gate-voltage pulse sequences. This graphene-based multifunctional device shows great potential for use in a simple, low-cost, and ultracompact nanomaterial-based nodal architecture to enable continuous, real-time event-based monitoring in pervasive healthcare IoTs, ubiquitous security systems, and other chemical/molecular/gas monitoring applications.

Automated Monitoring A Potential Solution for Achieving Sustainable Improvement in Hand Hygiene Practices

Article

Full-text available

May 2014

Adequate hand hygiene is often considered as the most effective method of reducing the rates of hospital-acquired infections, which are one of the major causes of increased cost, morbidity, and mortality in healthcare. Electronic monitoring technologies provide a promising direction for achieving sustainable hand hygiene improvement by introducing the elements of automated feedback and creating the possibility to automatically collect individual hand hygiene performance data. The results of the multiphase testing of an automated hand hygiene reminding and monitoring system installed in a complex continuing care setting are presented. The study included a baseline Phase 1, with the system performing automated data collection only, a preintervention Phase 2 with hand hygiene status indicator enabled, two intervention Phases 3 and 4 with the system generating hand hygiene reminding signals and periodic performance feedback sessions provided, and a postintervention Phase 5 with only hand hygiene status indicator enabled and no feedback sessions provided. A significant increase in hand hygiene performance observed during the first intervention Phase 3 was sustained over the second intervention Phase 4, with the postintervention phase also indicating higher hand hygiene activity rates compared with the preintervention and baseline phases. The overall trends observed during the multiphase testing, the factors affecting acceptability of the automated hand hygiene monitoring system, and various strategies of technology deployment are discussed.

The Effect of Automated Monitoring and Real-Time Prompting on Nurses’ Hand Hygiene Performance

Article

Full-text available

Aug 2013
CIN-COMPUT INFORM NU

Adequate hand hygiene compliance by healthcare staff is considered an effective method to reduce hospital-acquired infections. The electronic system developed at Toronto Rehabilitation Institute automatically detects hand hygiene opportunities and records hand hygiene actions. It includes an optional visual hand hygiene status indication, generates real-time hand hygiene prompting signals, and enables automated monitoring of individual and aggregated hand hygiene performance. The system was installed on a complex continuous care unit at the entrance to 17 patient rooms and a utility room. A total of 93 alcohol gel and soap dispensers were instrumented and 14 nurses were provided with the personal wearable electronic monitors. The study included three phases with the system operating in three different modes: (1) an inactive mode during the first phase when hand hygiene opportunities and hand hygiene actions were recorded but prompting and visual indication functions were disabled, (2) only hand hygiene status indicators were enabled during the second phase, and (3) both hand hygiene status and real-time hand hygiene prompting signals were enabled during the third phase. Data collection was performed automatically during all of the three phases. The system indicated significantly higher hand hygiene activity rates and compliance during the third phase, with both hand hygiene indication and real-time prompting functions enabled. To increase the efficacy of the technology, its use was supplemented with individual performance reviews of the automatically collected data.

Hand hygiene monitoring and real-time prompting system

Conference Paper

Mar 2012

10.1109/SysCon.2012.6189435

Back to the Future: Rising to the Semmelweis Challenge in Hand Hygiene

Article

Aug 2011
FUTURE MICROBIOL

Hand hygiene is the single most important intervention for reducing healthcare associated infections and preventing the spread of antimicrobial resistance. This sentence begins most publications regarding hand hygiene in the medical literature. But why - as we mark 150 years since the publication of Ignaz Semmelweis' landmark monograph on the subject - do we continue to repeat it? One might be tempted to regard it as a truism. However, while tremendous progress has certainly been made in this field, a significant amount of work is yet to be done in both strengthening the evidence regarding the impact of hand hygiene and maximizing its implementation. Hand hygiene cannot yet be taken for granted. This article summarizes historical perspectives, dynamics of microbial colonization and efficacy of hand cleansing methods and agents, elements and impacts of successful hand hygiene promotion, as well as scale-up and sustainability. We also explore hand hygiene myths and current challenges such as monitoring, behavior change, patient participation and research priorities.

A proposed approach to evaluate the accuracy of tag-based location systems

Conference Paper

Full-text available

Jan 2007

Acceptability of a wearable hand wash device with monitoring capabilities

Article

Full-text available

Oct 2008
J HOSP INFECT

Transmisssion of infection within healthcare institutions is a significant threat to patients and staff. One of the most effective means of prevention is good hand hygiene. A research team at Toronto Rehabilitation Institute, Ontario, Canada, developed a wearable hand disinfection system with monitoring capabilities to enhance hand wash frequency. We present the findingsof the first phase of a larger study addressing the hypothesis that an electronic hand hygiene system with monitoring and reminding propertieswill increase hand hygiene compliance. This first phase focused on the acceptability and usability of the wearable electronic hand wash device ina clinical environment. The feedback from healthcare staff to the first prototype has provided evidence for the research team to continue with the development of this technology.

Influence of Role Models and Hospital Design on the Hand Hygiene of Health-Care Workers

Article

Full-text available

Feb 2003
EMERG INFECT DIS

We assessed the effect of medical staff role models and the number of health-care worker sinks on hand-hygiene compliance before and after construction of a new hospital designed for increased access to handwashing sinks. We observed health-care worker hand hygiene in four nursing units that provided similar patient care in both the old and new hospitals: medical and surgical intensive care, hematology/oncology, and solid organ transplant units. Of 721 hand-hygiene opportunities, 304 (42%) were observed in the old hospital and 417 (58%) in the new hospital. Hand-hygiene compliance was significantly better in the old hospital (161/304; 53%) compared to the new hospital (97/417; 23.3%) (p<0.001). Health-care workers in a room with a senior (e.g., higher ranking) medical staff person or peer who did not wash hands were significantly less likely to wash their own hands (odds ratio 0.2; confidence interval 0.1 to 0.5); p<0.001). Our results suggest that health-care worker hand-hygiene compliance is influenced significantly by the behavior of other health-care workers. An increased number of hand-washing sinks, as a sole measure, did not increase hand-hygiene compliance.

Ultra wideband radio: A novel method for measuring wandering in persons with dementia

Article

Jan 2008
Gerontechnology

Wandering by persons with dementia is a complex syndrome of locomotive behaviors shaped by environmental, wanderer-specific and caregiver characteristics that vary the risk level for exiting, elopement, getting lost and accidental death. While valid and reliable methods to measure wandering exist, few have been evaluated for measurement of specific geographical patterns of wandering behavior as they occur in space and over time. In this paper we demonstrate how UWB-RFID can be used to unobtrusively and continuously measure two particularly high-risk wandering behaviors over intervals from weeks to months that occur in proximity to care setting exit points: lingering near exit doorways and shadowing (closely trailing behind) others who may exit.

RADAR: An in-building RF-based user location and tracking system

Article

Jan 2000

The proliferation of mobile computing devices and local-area wireless networks has fostered a growing interest in location-aware systems and services. In this paper we present RADAR, a radio-frequency (RF) based system for locating and tracking users inside buildings. RADAR operates by recording and processing signal strength information at multiple base stations positioned to provide overlapping coverage in the area of interest. It combines empirical measurements with signal propagation modeling to determine user location and thereby enable location-aware services and applications. We present experimental results that demonstrate the ability of RADAR to estimate user location with a high degree of accuracy.

Welsh, M.: MoteTrack: a robust, decentralized approach to RF-based location tracking. Personal Ubiquitous Comput. 11(6), 489-503

Article

Aug 2007

In this paper, we present a robust, decentralized approach to RF-based location tracking. Our system, called MoteTrack, is based on low-power radio transceivers coupled with a modest amount of computation and storage capabilities. MoteTrack does not rely upon any back-end server or network infrastructure: the location of each mobile node is computed using a received radio signal strength signature from numerous beacon nodes to a database of signatures that is replicated across the beacon nodes themselves. This design allows the system to function despite significant failures of the radio beacon infrastructure. In our deployment of MoteTrack, consisting of 23 beacon nodes distributed across our Computer Science building, we achieve a 50th percentile and 80th percentile location-tracking accuracy of 0.9 and 1.6m respectively. In addition, MoteTrack can tolerate the failure of up to 60% of the beacon nodes without severely degrading accuracy, making the system suitable for deployment in highly volatile conditions. We present a detailed analysis of MoteTrack’s performance under a wide range of conditions, including variance in the number of obstructions, beacon node failure, radio signature perturbations, receiver sensitivity, and beacon node density.

MoteTrack: A Robust, Decentralized Approach to RF-Based Location Tracking

Conference Paper

May 2005
Lect Notes Comput Sci

In this paper, we present a robust, decentralized approach to RF-based location tracking. Our system, called MoteTrack, is based on low-power radio transceivers coupled with a modest amount of computation and storage capabilities. MoteTrack does not rely upon any back-end server or network infrastructure: the location of each mobile node is computed using a received radio signal strength signature from numerous beacon nodes to a database of signatures that is replicated across the beacon nodes themselves. This design allows the system to function despite significant failures of the radio beacon infrastructure. In our deployment of MoteTrack, consisting of 20 beacon nodes distributed across our Computer Science building, we achieve a 50th percentile and 80th percentile location-tracking accuracy of 2 meters and 3 meters respectively. In addition, MoteTrack can tolerate the failure of up to 60% of the beacon nodes without severely degrading accuracy, making the system suitable for deployment in highly volatile conditions. We present a detailed analysis of MoteTrack’s performance under a wide range of conditions, including variance in the number of obstructions, beacon node failure, radio signature perturbations, receiver sensitivity, and beacon node density.

Electronic monitoring and voice prompts improve hand hygiene and decrease nosocomial infections in an intermediate care unit

Article

Feb 2004
CRIT CARE MED

To determine whether electronic monitoring of hand hygiene and voice prompts can improve hand hygiene and decrease nosocomial infection rates in a surgical intermediate care unit. Three-phase quasi-experimental design. Phase I was electronic monitoring and direct observation; phase II was electronic monitoring and computerized voice prompts for failure to perform hand hygiene on room exit; and phase III was electronic monitoring only. Nine-room, 14-bed intermediate care unit in a university, tertiary-care institution. All patient rooms, utility room, and staff lavatory were monitored electronically. All healthcare personnel including physicians, nurses, nursing support personnel, ancillary staff, all visitors and family members, and any other personnel interacting with patients on the intermediate care unit. All patients with an intermediate care unit length of stay >48 hrs were followed for nosocomial infection. Electronic monitoring during all phases, computerized voice prompts during phase II only. We evaluated a total of 283,488 electronically monitored entries into a patient room with 251,526 exits for 420 days (10,080 hrs and 3,549 patient days). Compared with phase I, hand hygiene compliance in patient rooms improved 37% during phase II (odds ratio, 1.38; 95% confidence interval, 1.04-1.83) and 41% in phase III (odds ratio, 1.41; 95% confidence interval, 1.07-1.84). When adjusting for patient admissions during each phase, point estimates of nosocomial infections decreased by 22% during phase II and 48% during phase III; when adjusting for patient days, the number of infections decreased by 10% during phase II and 40% during phase III. Although the overall rate of nosocomial infections significantly decreased when combining phases II and III, the association between nosocomial infection and individual phase was not significant. Electronic monitoring provided effective ongoing feedback about hand hygiene compliance. During both the voice prompt phase and post-intervention phase, hand hygiene compliance and nosocomial infection rates improved suggesting that ongoing monitoring and feedback had both a short-term and, perhaps, a longer-term effect.

Evidence-based model for hand transmission during patient care and the role of improved practices. WHO Global Patient Safety Challenge, World Alliance for Patient Safety

Article

Nov 2006
LANCET INFECT DIS

Hand cleansing is the primary action to reduce health-care-associated infection and cross-transmission of antimicrobial-resistant pathogens. Patient-to-patient transmission of pathogens via health-care workers' hands requires five sequential steps: (1) organisms are present on the patient's skin or have been shed onto fomites in the patient's immediate environment; (2) organisms must be transferred to health-care workers' hands; (3) organisms must be capable of surviving on health-care workers' hands for at least several minutes; (4) handwashing or hand antisepsis by the health-care worker must be inadequate or omitted entirely, or the agent used for hand hygiene inappropriate; and (5) the caregiver's contaminated hand(s) must come into direct contact with another patient or with a fomite in direct contact with the patient. We review the evidence supporting each of these steps and propose a dynamic model for hand hygiene research and education strategies, together with corresponding indications for hand hygiene during patient care.

Electronic surveillance of wall-mounted soap and alcohol get dispensers in an intensive care unit

Article

May 2007
J HOSP INFECT

We describe a battery-powered recording device incorporating a force-sensitive resistor and a microcontroller that records depressions of wall-mounted soap and alcohol gel dispensers. The device has a two-second (2 s) lockout built into it, so that a single record is associated with a single hand-hygiene episode. Recorders were implanted within the wall-mounted dispensers found in two bed areas and the entrance of a 16-bedded intensive care unit. The use of the bed area dispensers was correlated (r) with the dependency of the patient in the open bed area (r=0.5, P<0.01), as assessed using the UK Department of Health critical care minimum data set. Both bed areas and the entrance dispensers showed wide but different fluctuations in use throughout the 24h day. The recording device may help in feedback about soap and gel use for hand-hygiene quality improvement and educational initiatives.