GB2428298A - A hand monitoring apparatus comprising a fuel cell - Google Patents

Abstract

An apparatus arranged to detect the presence of a substance, such as alcohol, on a hand of an operator of said apparatus is described, the apparatus comprising a fuel cell 46 arranged to consume said substance to generate a signal indicative of the presence of said substance on said hand. In some forms of the invention, the apparatus comprises a means, such as a hood 42, for reducing the dissipation of said substance away from the vicinity of said fuel cell. In some forms of the invention, an activating means, such as an infra-red beam, is provided for activating said apparatus in the presence of a hand of an operator, wherein said activating means activates said apparatus without requiring the operator to contact any part of said apparatus.

Description

Monitoring Apparatus The invention relates to a monitoring device for

determining whether the hands of an individual have been cleaned in a prescribed manner.

There are many environments in which the cleanliness of hands is essential, for example hospitals, factories, food preparation areas and food manufacturing facilities. In environments such as these, it may be deemed necessary to monitor the cleaning of hands, for example after using toilet facilities. Further, such organisations may have a need to prove that they are complying with any relevant requirements.

JP 1219439 describes a system in which the hands of a user are cleaned in three stages, with each stage being monitored by a number of sensors to ensure compliance with a prescribed cleaning routine. First, the hands are washed at a washing station, with sensors being used to determine, inter alia, whether or not the hands are brought into contact with the flowing water and whether sufficient detergent is used. Second, the hands are rinsed at a rinsing station, with sensors being used to monitor the rinsing process. Third, the hands are dried at a drying station, with sensors being used to monitor the drying process.

GB 2 337 327 discloses a method of optical imaging that determines whether or not sufficient soap or detergent has been applied to hands. A digitised image of the hands is compared, pixel-by-pixel, with a reference image. The system requires that the soap is distinguishable from the hands in some way, for example by providing coloured soap.

A problem with a number of prior art systems, including the systems described above, is the complexity of the systems.

Complicated systems are expensive to install and require regular maintenance. The system of JP 1219439 requires the use and maintenance of a number of sensors and requires the data obtained from those sensors to be analysed. The system of GB 2 337 327 requires some way of distinguishing the soap from the hand of an operator.

Another problem with some prior art systems is the invasive nature of the monitoring. A system such as that of GB 2 337 327 may require an image to be taken before the user washes his hands, as well as after. This may not be acceptable to some users.

Yet another problem with many prior art systems is that they often monitor hand washing steps, such as the application of detergent, rather than determining from the washed hands themselves whether or not the required action has been taken. This problem has been at least partially addressed by GB 2 337 327, but that solution is complicated and likely to be difficult and expensive to implement, as discussed above.

A further problem identified with at least some prior art systems is that the user is often required to contact a handle or other mechanism at some stage after the hands have been cleaned. This may not be acceptable in some circumstances. For example, surgeons would not want to touch a handle after having cleaned their hands in case the handle is itself unclean.

The present invention seeks to address at least some of the problems identified above.

The present invention provides an apparatus arranged to detect the presence of a substance on a hand of an operator using said apparatus, the apparatus comprising a fuel cell arranged to consume said substance to generate a signal indicative of the presence of said substance on said hand, wherein the apparatus comprises means for reducing the dissipation of said substance away from the vicinity of said fuel cell.

The present invention also provides an apparatus arranged to detect the presence of a substance on a hand of an operator using said apparatus, the apparatus comprising a fuel cell arranged to consume said substance to generate a signal indicative of the presence of said substance on said hand, further comprising an activating means for activating said apparatus in the presence of a hand of an operator, wherein said activating activates said apparatus without requiring the operator to contact any part of said apparatus.

The present invention further provides a method of detecting the presence of a substance on a hand of an operator of an apparatus, the method comprising the steps of sensing a signal generated by a fuel cell that is arranged to consume said substance to generate a signal indicative of the presence of said substance on said hand, wherein the apparatus comprises means for reducing the dissipation of said substance away from said fuel cell.

The present invention yet further provides a method of detecting the presence of a substance on a hand of an operator of an apparatus, the method comprising the steps of sensing a signal generated by a fuel cell that is arranged to consume said substance to generate a signal indicative of the presence of said substance on said hand, wherein said step of activating said apparatus does not require the operator to contact any part of said apparatus.

In one form of the invention, an activating means is provided for activating the apparatus in the presence of a hand of an operator, without requiring the operator to contact any part of said apparatus. By way of example, the activating means may comprise an infra-red beam transmitted between an infra-red transmitter and an infra-red receiver.

Providing an activating means that does not require the operator to contact any part of the apparatus addresses the issue of operators needing to contact potentially unclean parts of an apparatus after the hand-cleaning process has been completed.

In one form of the invention, means for reducing the dissipation of said substance away from the vicinity of *said fuel cell are provided. By way of example, the means for reducing the dissipation of said substance away from said fuel cell may comprise a hood.

It is noted that the use of a means for reducing the dissipation of the said substance away from the vicinity of the fuel cell is particularly useful when used in an apparatus including means, such as an infra-red transmitter-receiver pair, for activating the apparatus in the presence of a hand of an operator, without requiring the operator to contact any part of said apparatus since the distance from the hand (the source of the alcohol) and the sensor may be high and may also be unpredictable to some extent if the user is able to place his hand anywhere between the transmitter and the receiver. The hood could, to of course, take many forms: the key feature of the hood is that it should restrict the dissipation of alcohol on an operator's hands away from the general vicinity of the sensor.

The substance consumed by the fuel cell may be a bactericide, such as alcohol. In one form of the invention, the said substance is one of the Cl-6 alkyl alcohols. As used herein, the term "alkyl" means both straight and branched chain saturated hydrocarbon groups.

Examples of alkyl groups include methyl, ethyl, n-propyl, iso-propyl, nbutyl, t-butyl, i-butyl, sec-butyl pentyl, hexyl, heptyl, octyl, nonyl and decyl groups. Among unbranched alkyl groups, there are preferred methyl, ethyl, n-propyl, iso-propyl, n-butyl groups. Among branched alkyl groups, there may be mentioned t-butyl, i-butyl, 1- ethylpropyl, 1-ethylbutyl and 1-ethylpentyl groups. In one exemplary form of the invention, the alcohol used is isopropyl alcohol.

In fact, any substance that acts to clean the hands of a user and that can also be used by the fuel cell to generate a detectable signal in the presence of that substance could be used.

The fuel cell provided to consume the substance may also consume other substances in a similar manner, or may be targeted to the particular substance.

The test for the presence of a substance, such as alcohol, on the hands of an operator provides a clear test. There is no need to monitor the hand-cleaning processing as in some prior art methods, since the presence or absence of alcohol is sufficient evidence of whether or not the hands have been cleaned. Further, there is no need for any testing or imaging of the hands prior to carrying out the steps of Figure 1.

An advantage associated with the detection of the use of alcohol as a cleaning agent is that the alcohol cannot typically be detected for very long after the cleaning process has taken place. Accordingly, the apparatus of the present invention only gives a positive result if the hands of an operator have been suitably cleaned recently. In some forms of the invention, this time may even be as short as 15 seconds. In other words, residual alcohol on the hands an operator that have been wiped using an alcohol wipe an hour earlier should not be detected by the apparatus.

The apparatus or method of the present invention may be activated by a start signal. The signal may be measured in response to said start signal.

The presence of said substance (e.g. alcohol) on the hand of said operator may be indicated by a rise in the said signal. If so, then the method of the invention may be arranged to detect a positive gradient of the signal, since a positive gradient would indicate the presence of said substance on said hand. In addition to, or instead of, measuring the gradient of the signal, a change in the absolute value of the signal may be measured over time in order to determine whether or not the substance is presence. Measuring the absolute signal change (rather than the gradient) may be useful when the background level of the substance is high.

A memory module may be provided for storing data relating to the use of the apparatus. This may be provided in conjunction with a real time clock that is provided to enable the times of actions to be recorded. Alternatively, or in addition, means for identifying the operator may be provided and may be recorded using the memory module.

The provision of a memory module that records data relating to the use of the apparatus may be useful in generating an audit trail.

The apparatus may be arranged to output a first signal in the presence of said substance and to output a second signal in the absence of said substance. Such a GO/NO-GO output may be used in a variety of ways, from a simple pair of LEDs or a buzzer arrangement to a more complex system of recording the data output. The first signal may be output on the activation of said method, thereby providing an indication that the method has been initiated. A variety of other means for indicating that the method has been initiated may be provided, for example, outputting both the first and the second signal on activation of said method and outputting a third signal on activation of said method.

Alternatively, or in addition, the GO/NO-GO signals may be used to activate or release a door lock, or to control the operation of a turnstile to either allow or refuse permission for a user to pass through the turnstile. The GO/NO-GO signals could also be used as inputs to an automated voice system which provides a voice message to a user dependent on whether or not the said substance is detected.

IS The apparatus of the present invention may control access by individuals into a clean area. For example, a corridor station may be separated into clean and dirty areas, with individuals only being allowed to enter the clean area if they are given permission to do so by the apparatus of the present invention.

Apparatuses in accordance with the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which: Fig. 1 is a flow chart showing the method of the present invention; Fig. 2 shows an apparatus in accordance with an embodiment of the present invention; Fig. 3 shows a fuel cell suitable for use with the present invention; Fig. 4 shows results of the use of an exemplary fuel- cell based sensor suitable for use with the present invention; Fig. 5 is a flow chart showing an algorithm carried out as part of the present invention; Fig. 6 is a flow chart showing further details of part of the algorithm shown in Fig. 5; Fig. 7 is a block diagram of a circuit for use with the present invention; Fig. 8 is a schematic circuit diagram of a first part of a circuit in accordance with an embodiment of the present invention; Fig. 9 is a schematic circuit diagram of a second part of a circuit in accordance with an embodiment of the present invention; Fig. 10 is a schematic circuit diagram of a third part of a circuit in accordance with an embodiment of the present invention; Fig. 11 is a schematic circuit diagram of a fourth part of a circuit in accordance with an embodiment of the present invention; Fig. 12 is a schematic circuit diagram of a fifth part of a circuit in accordance with an embodiment of the present invention; Fig. 13 shows a corridor station in accordance with an aspect of the present invention.

The system of the present invention makes use of the fact that alcohol, such as isopropyl alcohol, can be used as an effective bactericide. Thus, alcohol-based cleansing products, such as wipes, can be used to clean hands with a high degree of effectiveness.

Figure 1 is a flow chart that demonstrates, in broad terms, the method of the present invention. The method starts at step 2 at which point a user uses an alcohol-based wipe to clean his hands. Next, at step 4, the user presents his/her hands to a monitoring apparatus for checking. The monitoring apparatus is arranged to detect the presence of alcohol on the hand and this process is carried out at step 6. Finally, a Go/No-Go signal is output at step 8 in dependence on whether or not sufficient alcohol has been detected. There are a number of variants to the method as shown in Figure 1 that will become apparent by reading this specification. For example, the alcohol-based wipes referred to in step 2 could be replaced with the use of an alcohol gel, and the GO/NO-GO output at step 8 could be changed in a number of ways.

Figure 2 is a schematic cross-section showing a hand sensor arrangement, indicated generally by the reference numeral 40, in accordance with an embodiment of the present invention. The sensor arrangement 40 includes a hood 42 attached to a wall 44. A sensor 46 is mounted within the hood. Also mounted within the hood 42 are an infra-red transmitter 48 and receiver 50 pair. An infra-red beam is transmitted from the transmitter 48 to the receiver 50: the reception of the beam at the receiver 50 indicates that there is no obstruction between the receiver and the transmitter; a failure to detect the beam at the receiver indicates that an obstruction, such as the hand of a user, is present. The sensor arrangement 40 is activated when the infra-red beam is broken and is used to determine whether or not the concentration of alcohol in the atmosphere around the sensor indicates that the hand of the operator has been cleaned using the alcohol based wipes, thereby performing the step 6 described above.

As shown in Figure 2, a display 52 is provided on the exterior of the hood 42. The display may take many forms.

In one embodiment, the display 52 includes separate "PASS" and "FAIL" indicator lights. If the output of the sensor 46 indicates that the hand of the operator has been cleaned using alcohol based wipes, a PASS indicator light is lit; otherwise a FAIL indicator light is lit. Thus, the step 8 is performed.

There are a number of requirements for the design of an ideal sensor circuit. For example: * The sensor circuit should normally be in a low power, standby mode in order to conserve power since a sensor that consumes a lot of power will either need to be connected to a mains supply of power (which may be expensive, potentially dangerous and inconvenient) or will require regular maintenance to replace batteries.

* The sensor should be quickly operational once it is activated so that the operator does not have to wait long for the sensor to be operational.

* Once activated, the sensor should sense the level of alcohol in the surrounding atmosphere and provide an accurate reading within a short space of time.

* The sensor should have a short cleaning period, during which the sensor is cleared of alcohol so that the sensor is ready for use again within a short space of time.

* The sensor should be cheap, reliable and durable to avoid the cost of the system being prohibitive.

* The sensor should have low maintenance requirements.

The sensor used to carry out step 6 described above is a conventional fuel cell. A fuel cell consists of two electrodes (an anode and a cathode) that act as catalysts separated by an electrolyte. In the use of the fuel cell, hydrogen is provided at the anode and oxygen is provided at the cathode. When a hydrogen molecule comes into contact with the catalyst, it splits into two H ions (that pass through the electrolyte to the cathode) and two electrons (that pass to the cathode via an electrical connection between the anode and cathode) . The H ions and the electrons recombine at the cathode, together with oxygen, to form water. Thus, electricity is generated in the form of the electrons passing through the electrical connection can be used, with water being the only waste product.

Figure 3 shows a fuel-cell, indicated generally by the reference numeral 20, that can be used to generate an electric current from alcohol. The fuel-cell 20 comprises a platinum electrode 22 forming an anode, a platinum electrode 24 forming a cathode, an electrolyte 26 between the electrodes 22 and 24, an electrical connection 28 between the electrodes 22 and 24 and an electrical circuit 30.

In the use of the fuel-cell 20, alcohol is converted into acetic acid and hydrogen by using a reformer in a manner that is well known in the art. The hydrogen molecules split as described above with the H ions passing through the electrolyte 26 in the direction indicated by the arrow 32 and the electrons passing from the anode to the cathode via the electrical connection 28 and the electrical circuit 30 as indicated by the arrow 34. The acetic acid is a waste product.

The fuel cell 20 can be used to generate an electrical current that is proportional to the concentration of alcohol that it is exposed to. Thus, the fuel cell 20 can be used as a power source for a sensor circuit of the present invention. Fuel-cell technology has been used in breathalyzers to measure the blood alcohol level of a driver in this manner.

Fuel cells that are suitable for use with the present invention are readily available. For example, a suitable sensor is the Dart AQ sensor available from Dart Sensors Limited, Dart Marine Park, Totnes, Devon TQ9 5AL, England.

The Dart AQ sensor is sensitive to carbon monoxide, sulphur dioxide, hydrogen sulphide, aldehydes, hydrogen, ether, ethylene, phenol and nitrogen dioxide as well as alcohols such as isopropyl alcohol. Accordingly, the Dart AQ sensor is not targeted specifically to the substance that is used to clean the hands of an operator of the sensor arrangement. Sensors that are more targeted are available and could be used instead of the Dart AQ sensor, however, one of the principal advantages of the Dart AQ sensor is that it makes use of fuel cell technology and is therefore itself a power source. This enable the sensor to be used in a low cost, low power application, as described below.

Figure 4 shows test results obtained by using the Dart AQ sensor. The sensor was turned on for three seconds and then turned off for seven seconds. This ten-second cycle was repeated a number of times. The hand of the operator was cleaned after each cycle using an alcohol wipe, with a fresh wipe being used every second application.

Initially, the sensor output is zero, and it stays at zero until the sensor is turned on at 15 seconds. When the to sensor is turned on (at 15 seconds), the hand of the operator is in the vicinity of the sensor 46. Since alcohol is present on the hand, the sensor consumes that alcohol and a current is generated as electrons flow through the electrical circuit 30. Thus, the sensor output rises.

When the operator's hand is removed (at 18 seconds), the concentration of alcohol reduces, and so the sensor output begins to fall. The sensor output does not fall to zero, because the fuel cell 20 is still able to consume the alcohol left in the surrounding atmosphere. This consumption of the remaining alcohol in the atmosphere by the sensor is an advantage of the present invention because it reduces the cleaning time of the sensor.

The sensor is activated again at 25 seconds, where the amount of alcohol is increased by the presence of the operator's hand and therefore the sensor output rises again. The sensor output falls once more after the operator's hand is removed.

At 35 seconds, the sensor circuit is turned on once again, but this time a fresh alcohol-based wipe has been used to clean the operator's hand and so the amount of alcohol present is increased. As a result, the sensor output rises sharply, before falling again after the operator's hand is removed at 38 seconds.

At 45 seconds, the sensor circuit is turned on for a fourth time. By this time, the background alcohol level is quite high because the fuel cell has not had time to clear the high level of alcohol present around the sensor and that alcohol has not had time to dissipate to the surrounding atmosphere. Accordingly, although the sensor output increases as a result of the operator's hand being present, the increase is small.

At 55 seconds, the sensor circuit is turned on again and another sharp rise in the sensor output is seen because a fresh wipe has been used.

At 65 seconds, the sensor circuit is turned on, but the rise in the sensor output is very small, due to the high

level of background alcohol.

At 75 seconds, the sensor circuit is turned on once more.

A small rise is seen, despite a fresh wipe having been used. The rise is small because the background level of alcohol is high.

At 85 seconds, the sensor circuit is turned on and another small rise is detected.

At 95 seconds, the sensor circuit is turned on again, but this time the circuit is turned on for 5 seconds and the operator's hand was held in the vicinity of the sensor 46 for 5 seconds. It can be seen that the sensor output rise in increased by the increased presence of the operator's hand, but that the gradient of the increase is not much different than at 75 or 85 seconds.

The sensor circuit is turned on again at 105, 115 and 125 seconds. A small rise in the sensor output is detected each time.

It can be seen from Figure 4 that the presence of alcohol on an operator's hand can be determined by a rise in the sensor output when the sensor arrangement is activated.

This rise is most pronounced when the hands have been recently cleaned with a fresh wipe, but becomes more difficult to observe when the sensor has been repeatedly used. The sensor must be given time to consume the alcohol surrounding the sensor if the sensor is to be reliable.

Another feature of the present invention that can be seen in Figure 4 is that when the apparatus is in regular use, the fuel cell output does not have the chance to return to zero. This causes problems when trying to determine the amount of alcohol on an operator's hand in absolute terms.

It can also be seen in Figure 4 that the sensor output tends to continue to rise for a brief period after the user has removed his/her hand, before beginning to fall.

Figure 5 is a flow-chart showing one algorithm, indicated generally by the reference numeral 103, for the functionality of the sensor arrangement 40.

The algorithm 103 assumes that the display 52 of the sensor arrangement 40 includes a "GO" light and a "NOGO" light.

When the sensor arrangement 40 is inactive, both the GO and the NOGO lights are off. When the sensor arrangement is active and detects the presence of alcohol, the GO light is lit. When the sensor arrangement is active, but does not detect the presence of alcohol, the NOGO light is lit.

When the sensor arrangement is active, but has not determined whether or not alcohol is present, both the GO and NOGO lights are lit.

At step 104 of the algorithm 103, both the GO and the NOGO lights are off (GO=0 and NOGO=0) indicating that the sensor circuit of the sensor arrangement 40 is inactive.

At step 106 of the flow chart 103, a microcontroller 148 determines whether or not the infra-red beam transmitted by transmitter 48 has been broken. If the beam has not been broken, the step 106 simply repeats. If the beam is not being received by the receiver 50 (indicating that the beam has been broken), the algorithm moves on to step 108. Step 106 may be implemented as an interrupt routine, with the output of the receiver 50 being connected to an interrupt input of the microcontroller 148 in a manner well known to the person skilled in the art.

Both the GO and the NO-GO lights are activated at step 108, indicating that the sensor arrangement is active, but that the sensor 46 has not yet determined whether or not the required alcohol is present. The algorithm then moves on to step 110, where it is determined whether or not the required alcohol is present.

If the required alcohol is detected at step 110, then the algorithm 103 moves to step 112, where the GO light is active (GO=l) and the NOGO light is inactive (NOGO=0).

From step 112, the algorithm 103 moves to step 116 where it is determined whether or not the sensor is ready to take a further reading. If the sensor is not ready, the step 116 is repeated. If the sensor is ready, the algorithm returns to the step 104, described above.

If the required alcohol is not detected at step 110, then the algorithm 103 moves to step 118, where the GO light is inactive (GO=0) and the NOGO light is active (NOGO=l).

From step 118, the algorithm moves to delay step 120, which is provided to ensure that the NOGO output is visible to the operator. From step 120, the algorithm returns to the step 104 described above.

An additional delay step (not shown), similar to delay step 120, may be included between steps 112 and 116 to ensure that the GO output is visible to the operator.

The step 110 of the flow chart 103 in which the microprocessor determines whether or not the required alcohol is present can be implemented in a number of different ways, such as the method described with reference to Figure 6.

Figure 6 is a flow chart, indicated generally by the reference numeral 82 that can be used to implement the step of the algorithm 103 of Figure 5.

The algorithm 82 starts at step 84 (which is entered from step 108 of algorithm 103). At step 84, it is determined whether or not the output of the sensor has a gradient greater than a predetermined value, X. If the gradient is greater than X, then the algorithm moves to step 112 of algorithm 103, otherwise, the algorithm 82 moves to step 86.

At step 86, it is determined whether the absolute value of the sensor output has risen by more than a predetermined value, Y, since the sensor 46 was activated. If the sensor output has risen by more than Y, then the algorithm moves to step 112 of algorithm 103, otherwise the algorithm 82, moves to step 88.

At step 88, it is determined whether a predetermined time, Z, has elapsed since the sensor 46 was activated. If so, then it is determined that the required alcohol is not present and the algorithm returns to step 118 of algorithm 103. If not, then the algorithm 82 returns to step 84.

Steps 84, 86 and 88 then repeat until the required gradient is detected, the required absolute rise is detected, or the time Z expires.

Of course, there are a number of ways of determining the gradient of the output of the sensor. One simple example is to take two readings of the sensor output, separated by a short period of time. If the second reading is higher than the first, then the slope between them must be positive. It may be necessary to introduce a threshold rise, below which the slope is considered too small to be indicative of a rise. A more sophisticated approach might take a number of readings to ensure that an apparent riseis not simply caused by the effects of noise. Another approach would be to provide an analogue differentiator to provide a signal indicative of the gradient of the sensor output. Other ways of implementing the step 84 will be apparent to the skilled person, as will ways of implementing the steps 86 and 88.

The "ready" step 116 described above can be implemented in a number of ways. The purpose of the step 116 is to ensure that the sensor is ready of use again, before the algorithm 103 returns to step 104. The step 116 ensures that some of the alcohol present around the sensor is consumed and/or dissipates before another operator can activate the sensor, thereby ensuring that the background level of alcohol does not get too high. One way of achieving this is to record the sensor output at step 112, and to wait until that sensor output has fallen by a predetermined amount (either in absolute terms and/or in percentage terms) . For example, the step 116 may be repeated until the sensor output has fallen to 5 percent below the level measured at step 112. Of course, other values are possible. As shown in Figure 4, it may take a few seconds for the sensor output to fall to five percent below the level measured at step 112 since the sensor output tends to continue to rise for a brief period after the operator's hand is moved away from the sensor before it begins to fall.

The values of X, Y and Z used in steps 84, 86 and 88 respectively, and the values used in ready step 116 and delay step 120 (and any delay step between steps 112 and 116), are likely to vary from application to application.

The likely slope gradients and absolute sensor output rise depends on both the sensor used and the cleaning wipes used. Similarly, the time over which the measurements are taken will vary with the sensor and cleaning wipes used.

Figure 7 is a block diagram of a circuit in which the sensor of the present invention is used. The circuit, indicated generally by the reference numeral 140, comprises a sensor 142, a hand detector 144, an amplifier 146, a microcontroller 148, a display 150, power source 152 and a IS real time clock 154. The display 150 includes a GO/NO-GO display 156 and a battery display 158. The power source 152 includes a battery 160 and a DC-DC converter 162.

The sensor 142 is a fuel cell sensor, such as the Dart AQ sensor described above. An output of the sensor 142 is coupled to the input of the amplifier 146. The amplifier 146 amplifies the output of the sensor and passes the amplified sensor signal to an input of the microcontroller 148.

The hand detector 144 could take one of many forms. It could, for example, be in the form of an infra-red beam between two sensors, 48 and 50, as shown in Figure 2. The output of the detector 144 is coupled to an input of the microcontroller 148. The microcontroller 148 has an output coupled to a display 150. The display 150 includes GO/NO- GO display 156 that displays the GO and NO-GO signals described above and described in more detail below.

The power source 152 provides power to the hand detector 144, the amplifier 146 and the microprocessor 148. As discussed above, the fuel cell sensor 142 does not itself require a source of power (it can itself be viewed as a power source, as described above) In use, the output of the fuel cell 142 is amplified by the amplifier 146 and provided as an input to the microcontroller 148. The microcontroller 148 ignores the data received from the sensor 142 until the hand detector 144 is activated. Once the hand detector has been activated, both the NO- GO light and the GO light are lit in the GO/NO-GO display 156, indicating that the sensor is determining whether or not the required alcohol is present.

The microcontroller 148 then determines whether or not alcohol is present on the hand of the operator. If alcohol is detected, the GO light is lit (and the NOGO light is not lit): if no alcohol is detected, the NOGO light is lit (and the GO light is not lit) As mentioned above, the power source 152 includes a battery 160 and a DC-DC converter 162. The provision of a DC-DC converter enables a low voltage battery to be used to power circuitry that requires a higher voltage by stepping up that voltage using the DC-DC converter 162 in a manner well known in the art.

The battery display 158 mentioned above may consist of a single LED that is lit when the battery level is sufficient and is off when the battery level is insufficient, thereby providing a visual indicator to an operator regarding whether or not the battery needs to be replaced. Of course, more sophisticated display mechanisms could be used. For example, the battery level indicator could consist of a numbers of LED5, with the number of LED5 being lit being proportional to the level of power available from the battery 160. In one form of the invention, a battery test switch is provided in order to allow a maintenance engineer to activate the battery level indicator.

The real time clock 154 is powered by the power source 152 and has an output coupled to an input of the microcontroller 148. The real time clock 154 counts the seconds, minutes, hours, months and years since the power source was last interrupted. The real time clock is used to monitor the usage of a battery that is used as the power source 152. The microcontroller 148 uses the information obtained from the real time clock, together with information relating to the usage of the battery, to determine the likely level of power remaining in the battery, in a manner well known in the art. Thus, in the exemplary circuit of Figure 7, the real time clock 154 is used as part of the battery level indicator circuitry.

Figures 8 to 12 show circuit schematic of one implementation of the present invention. The sensor 142, amplifier 146, microcontroller 148, display 150, power source 152 (including DC-DC converter 162) and real time clock 154 are indicated with dotted lines in the circuit schematics of Figures 8 to 12.

Figure 8 shows a sensor 142 having an output coupled to the input of amplifier 146. In the example of Figure 8, the amplifier 146 is implemented using a LMV2O11 rail-to-rail operational amplifier. The output of the amplifier (i.e. the amplified sensor output) is coupled to a P1C16F876 microcontroller 146, as shown in Figure 9. Figure 10 shows the power source 152 including a DC-DC converter 162 implemented using a MAX17O5/6 step-up DC-DC converter.

Figure 11 shows a real time clock 154 implemented using Serial Alarm RealTime Clock DS1305. Figure 12 shows the display 150.

In the circuits shown in Figures 8 to 12, the amplifier 146 is implemented using a LMV2O11 rail-to-rail operational amplifier, the microcontroller 148 is a PIC16F876 microcontroller, the real time clock 154 is implemented using Serial Alarm Real-Time Clock DS1305 and the DC-DC converter 162 is implemented using a MAX17O5/6 step-up DC- DC converter. Each of these devices is available from many semiconductor suppliers. Each of these devices may be replaced with other similar devices. Further, the functionality of the devices described above may be implemented in other ways, as would be apparent to the person skilled in the art.

The output of the microcontroller 148 may be used for a variety of other purposes in addition to, or instead of, activating Go/No-Go LED5. For example, an audible alarm, perhaps in the form of a buzzer, may be activated when the sensor arrangement is activated by an operator who hasn't used an alcohol wipe to clean his hands. The GO signal described above may be used to release a door lock, so that it is only possible to open the door if the appropriate alcohol level is detected. The GO signal may result in a voice message, such as "Thank you for cleaning your hands" to be output and a NOGO signal may result in a voice message, such "Please clean your hands" to be output. A combination of two or more of the options listed above could be used. Furthermore, other uses of the GO/NOGO outputs, such as providing control signals for a turnstile, will be apparent to the person skilled in the art. In one embodiment of the invention, the real-time clock 154 is used to turn off any audible output at night. This is useful when the audible output might disturb people, for example patients in a hospital in which the sensor arrangement is used.

Figure 13 shows a corridor, indicated generally by the reference numeral 200, that makes use of an aspect of the present invention. The corridor 200 includes a "clean" area 202 and a "dirty" area 204. An imaginary boundary 206 between the dirty and clean areas is shown. A sensor arrangement 208 is positioned at the boundary 206, together with a dispenser 210. The sensor arrangement 208 may be similar in form to the sensor arrangement 40 described above with reference to Figure 2. The dispenser 210 may dispense alcohol gel or alcohol wipes for cleaning hands.

In the use of the system of Figure 9, persons are only allowed to enter the clean area 202 if they have cleaned their hands using the substance dispensed by the dispenser 210 and have had their hands checked and passed by the sensor arrangement 208.

In the example of Figure 13, no mechanism is provided for preventing an individual from entering the clean area without using the sensor arrangement 208. Of course, such an arrangement could be provided. For example, a door could be provided having a lock under the control of the detector hood 208. Similarly, a turnstile under the control of the sensor arrangement 208 could be provided.

The present invention may store data relating to the use of the sensor so that statistics can be determined regarding how often users are identified as having cleaned their hands in the prescribed manner and how often users have not been so identified. Such recordal of data for subsequent analysis may be seen as more acceptable than preventing an operator from opening the door if the hand has not been cleaned in the prescribed manner. Recording data relating to the usage of the system also enables an audit trail to be created, thereby enabling a company, for example a factory owner, to prove that they have met requirements relating to hand cleaning. The provision of real time clock 154 also enables the microcontroller to record data relating to the time of use of the door sensor arrangement.

In another aspect of the invention, a means for identifying an operator of a sensor arrangement in accordance with the invention is provided. The identifying means may, for example, be a badge detection loop. In this way, individual operators can be identified. Data recordal of the type described above may be recorded together with operator identification data, thereby providing a means of recording use of the sensor arrangement and the outcome of each use (in terms of GO/NO-GO output) for each operator.

As noted above, recording data relating to the usage of the system also enables an audit trail to be created, thereby enabling a company, for example a factory owner or a hospital, to prove that they have met requirements relating to hand cleaning.

The sensor module may have a simple GO/NO-GO output pair that is capable of driving a number of different indicator options. In this form of the invention, the form of the output does not need to be part of the sensor module design.

Claims (31)

1. CLAIMS: 1. An apparatus arranged to detect the presence of a substance on

   a hand of an operator using said apparatus, the apparatus comprising a fuel cell arranged to consume said substance to generate a signal indicative of the presence of said substance on said hand, wherein the apparatus comprises means for reducing the dissipation of said substance away from the vicinity of said fuel cell. I0
2. 2. An apparatus as claimed in claim 1, further comprising an activating means for activating said apparatus in the presence of a hand of an operator, wherein said activating activates said apparatus without requiring the operator to contact any part of said apparatus.
3. 3. An apparatus arranged to detect the presence of a substance on a hand of an operator using said apparatus, the apparatus comprising a fuel cell arranged to consume said substance to generate a signal indicative of the presence of said substance on said hand, further comprising an activating means for activating said apparatus in the presence of a hand of an operator, wherein said activating activates said apparatus without requiring the operator to contact any part of said apparatus.
4. 4. An apparatus as claimed in claim 2 or claim 3, wherein said activating means comprises an infra-red beam transmitted between an infra-red transmitter and an infra- red receiver.
5. 5. An apparatus as claimed in claim 3 or claim 4 when dependent on claim 3, wherein the apparatus comprises means for reducing the dissipation of said substance away from the vicinity of said fuel cell.
6. 6. An apparatus as claimed in claim 1, claim 2 or claim 5, wherein said means for reducing the dissipation of said substance away from said fuel cell comprises a hood.
7. 7. An apparatus as claimed in any preceding claim, wherein said substance is a bactericide.
8. 8. An apparatus as claimed in claim 7, wherein said substance is an alcohol.
9. 9. An apparatus as claimed in any preceding claim, wherein an increase in said signal is indicative of the presence of said substance on the hand of said operator.
10. 10. An apparatus as claimed in any preceding claim, further comprising a memory module for storing data relating to the use of the apparatus.
11. 11. An apparatus as claimed in any preceding claim, wherein the apparatus is arranged to output a first signal in the presence of said substance and to output a second signal in the absence of said substance.
12. 12. A corridor station comprising an apparatus as claimed in any one of claims 1 to 11, wherein access to a clean area is allowed only when the presence of said substance is detected on the hand of the operator.
13. 13. A corridor station as claimed in claim 12, further comprising a turnstile to provide access to said clean area when the presence of said substance is detected and to deny access to said clean area when the presence of said substance is not detected.
14. 14. A method of detecting the presence of a substance on a hand of an operator of an apparatus, the method comprising the steps of sensing a signal generated by a fuel cell that is arranged to consume said substance to generate a signal indicative of the presence of said substance on said hand, wherein the apparatus comprises means for reducing the dissipation of said substance away from said fuel cell.
15. 15. A method as claimed in claim 14, further comprising the step of activating said apparatus in the presence of a hand of an operator, wherein said step of activating said apparatus does not require the operator to contact any part of said apparatus.
16. 16. A method of detecting the presence of a substance on a hand of an operator of an apparatus, the method comprising the steps of sensing a signal generated by a fuel cell that is arranged to consume said substance to generate a signal indicative of the presence of said substance on said hand, wherein said step of activating said apparatus does not require the operator to contact any part of said apparatus.
17. 17. A method as claimed in claim 15 or claim 16, wherein said step of activating said apparatus makes use of an infra-red beam transmitted between an infra-red transmitter and an infra-red receiver.
18. 18. A method as claimed in claim 16 or claim 17 when dependent on claim 16, wherein the apparatus comprises means for reducing the dissipation of said substance away from said fuel cell.
19. 19. A method as claimed in claim 14, claim 15 or claim 18, wherein said means for reducing the dissipation of said substance away from said fuel cell comprises a hood.
20. 20. A method as claimed in any one of claims 14 to 19, wherein said substance is an alcohol.
21. 21. A method as claimed in any one of claims 14 to 20, wherein the step of sensing said signal is performed in response to a start signal.
22. 22. A method as claimed in claim 21, further comprising the step of said operator activating said start signal.
23. 23. A method as claimed in any one of claims 14 to 22, further comprising the step of measuring the gradient of said signal, wherein a positive gradient is indicative of the presence of said substance on the hand of said operator.
24. 24. A method as claimed in any one of claims 14 to 23, further comprising the step of measuring a change in the absolute value of said signal, wherein a change of more than a predetermined amount is indicative of the presence of said substance on the hand of said operator.
25. 25. A method as claimed in any one of claims 14 to 24, further comprising the step of outputting a first signal in the presence of said substance and outputting a second signal in the absence of said substance.
26. 26. A method as claimed in claim 25, further comprising the step of using said first and second signals so that access to a clean area is only granted when said substance is detected on the hand of the operator.
27. 27. A method as claimed in any one of claims 14 to 26, further comprising the step of making a record of the use of said method.
28. 28. A method of controlling the movement of persons from an unclean area to a clean area, the method comprising determining whether one or more hands of a person have been cleaned in a prescribed manner using an apparatus as claimed in any one of claims 1 to 13 and allowing access to said clean area only when said apparatus determine that said person has clean hands.
29. 29. An apparatus arranged to detect the presence of a substance on a hand of an operator using said apparatus substantially as hereinbefore described with reference to, and shown in, the accompanying drawings.
30. 30. A method of detecting the presence of a substance on a hand of an operator of an apparatus substantially as hereinbefore described with reference to, and shown in, the accompanying drawings.
31. 31. A method of controlling the movement of persons from an unclean area to a clean area substantially as hereinbefore described with reference to, and shown in, the accompanying drawings.