the present invention describes methods and systems that electronically monitor and log the contamination status and cleaning status of a cleanable touch surface . this is made possible by sensors that are incorporated into the surface including , but not limited to , capacitive touch sensors , which can be employed to detect when the surface has been cleaned ( and how well it has been cleaned ). fig1 shows a simplified block diagram of the hardware components of a typical device 100 in which the system and method for a cleanable touch surface is implemented . the device 100 includes one or more touch sensors 120 that provides input to the cpu ( processor ) 110 notifying it of contact events when the surface is touched , typically mediated by a hardware controller that interprets the raw signals received from the touch sensor ( s ) and communicates the information to the cpu 110 using a known communication protocol via an available data port . similarly , the device 100 includes one or more motion ( or vibration ) sensors 130 that communicate with the cpu 110 when the surface is tapped , in a manner similar to that of the touch sensor ( s ) 120 . the cpu 110 communicates with a hardware controller for a visual output 140 to send user alerts . a speaker 150 is also coupled to the cpu 110 so that any appropriate auditory signals can be passed on to the user as guidance . a vibrator 135 is also coupled to the cpu 110 to provide appropriate haptic feedback to the user . the cpu 110 has access to a memory 160 , which may include a combination of temporary and / or permanent storage , and both read - only and writable memory ( random access memory or ram ), read - only memory ( rom ), writable non - volatile memory such as flash memory , hard drives , floppy disks , and so forth . the memory 160 includes program memory 170 that contains all programs and software such as an operating system 171 , contamination monitor software 172 , cleaning monitor software 173 , and any other application programs 174 . the memory 160 also includes data memory 180 that includes a sensor database ( s ) 181 required by the contamination monitor software 172 and the cleaning monitor software 173 , storage for maintaining a record of user options and preferences 182 , and any other data 183 required by any element of the device 100 . the cpu 110 may send information related to the contamination levels and cleaning status of the cleanable touch surface 100 to external devices or controllers by communicating through a standard communication interface 115 . fig2 a through 2c show a process flow chart of an exemplary process performed by the contamination monitor software 172 and the cleaning monitor software 173 . the flowcharts shown in fig2 a to 2c are not intended to fully detail the software of the present invention in its entirety , but are used for illustrative purposes . fig2 a shows a flow chart of the main processing routine 2100 performed by the contamination monitor software 172 and the cleaning monitor software 173 . at block 2110 the process invokes a contamination monitor sub - routine ( fig2 b ) to determine the level of contamination on the surface . at block 2120 the system determines whether or not the contamination level exceeds a specified threshold . this threshold is a user - changeable variable that is typically defined via a software control panel or through a user interface provided by the device 100 and stored in user preference memory 182 . if the contamination level has not exceeded the defined threshold , the process returns back to block 2110 to continue monitoring for contamination . if the contamination threshold has been exceeded , the process moves to block 2120 where it outputs an alert according to administrator - defined policy . the alert can take many forms including , but not limited to : visual indicator displayed on the visual output 140 ( e . g ., display device or device configured to illuminate the touch surface ) of the device 100 , an audible alert output on the speaker 150 , a haptic alert output by the vibrator 135 , or data that is sent via the communication interface 115 to external monitoring devices or software . after issuing an alert , the process moves to block 2130 ( fig2 c ) where it monitors for cleaning actions taken . in block 2140 , the system decides whether or not cleaning has been sufficient . what is deemed sufficient by the cleaning monitor software 173 is defined by an administrator and stored as a user preference in the memory 182 . if cleaning has not been sufficient , the process returns to block 2130 to continue monitoring for cleaning activities . if the cleaning is sufficient , the process moves to block 2150 where the alert is cleared ( or stopped ). the process then returns to the start and once again begins monitoring for contamination in block 2110 . fig2 b shows a flowchart of an exemplary process for determining the contamination levels . the routine begins at block 2200 and continues for each contamination criteria in block 2210 . there are many factors determined by the cpu 110 based on sensor and / or other data that can contribute to the cleanable surface becoming contaminated . by way of example , these might include : how often the device incorporating the cleanable surface has been moved , the number of times a different user has used the device , changes to the normative values of the touch sensors , a passage of time , the number of times the surface has been touched , and the number of times a human was detected within the proximity of the device . this list is not intended to be exhaustive and it will be evident to anyone skilled in the art that other criterion for determining contamination exists . each contamination criteria examined in block 2210 will contribute to a contamination score in block 2220 and the process repeats for each criteria in block 2230 . once all contamination criteria have been examined , the process returns with a contamination score at block 2240 . fig2 c shows a flowchart of an exemplary process for determining the cleaning levels of the touch surface . the routine begins at block 2300 and retrieves the stored baseline value ( s ) for the touch capacitive sensors . these are the normative signal levels registered by the sensors when they are dry and not being touched . in one embodiment , the cpu 110 dynamically updates these normative values over time , to adapt to any changes in environment , signal degradation , or other factors which may affect the sensor &# 39 ; s signal . touch capacitive sensors are particularly useful in this application since the signal registered by each sensor differs if the surface is wet or dry . thus , they can be used to detect the presence of liquid . when the surface is wiped using a liquid , the moisture effects the capacitance of the surface uniformly . this provides a second means whereby the adequacy of the cleaning of the surface can be determined ( in addition to wipe detection ). if , for example , a user has wet fingers , only the areas they touch on the surface will be affected by the moisture while other areas that remain dry will not . this information can easily be used to determine the difference between touching with wet fingers and the surface being wiped uniformly with a liquid . the system then watches for a wiping motion in block 2310 . in one embodiment , the cpu 110 determines when the surface has been cleaned by a wiping action . wipe detection is particularly useful when a user initiates cleaning the surface but has forgotten to pause it first . if the system detects touches that are indicative of a wiping action , it can automatically suspend or pause the operation of the device . in one embodiment , the device has an explicit method for the user to select pause mode , which disables functionality to allow the surface to be cleaned . a user may forget or choose not to activate this mode before cleaning . to accommodate this circumstance , the cpu 110 detects a wiping motion as a moving cluster of adjacent touches occurring simultaneously . as that cluster of touches begins to move , the cpu 110 determines the action to be a wiping motion and functionality of the device is temporarily disabled , allowing the wiping motion to take place without the pause mode being manually activated . if a wiping motion is not detected , the process exits at block 2315 . if a wiping motion is detected , the system suspends operation of the device in block 2320 . in block 2325 the cpu 110 determines if wipe coverage was adequate . for example , if only half of the touch surface was wiped , the cpu 110 automatically ascertains this and judges this wiping action to be an incomplete wipe . in infection sensitive environments , the contamination on the surface may not be visible to the naked human eye . in fact , the most harmful pathogens are almost always invisible . in this circumstance , the user doesn &# 39 ; t have the benefit of seeing where they have or haven &# 39 ; t wiped by simply looking at the presence or absence of contamination . further , many cleaning liquids are clear again making it difficult for a user to know if they have cleaned the entire surface adequately . to assist with this problem , an embodiment of the cleanable surface incorporates a virtual visual representation of the surface on a display ( either attached to the surface or on the screen of a connected computer ( the visual output 140 )). this visual representation , sometimes referred to as a “ heat map ”, changes the color of the virtual surface ( or touch surface ) wherever a touch occurs . over time , the more the surface is touched , the more the virtual surface ( or touch surface ) becomes colored . as the user wipes the cleanable surface , the virtual surface representation provides feedback whereby the colorization is removed corresponding to where the wiping takes place . in effect , the user “ erases ” the coloring on the virtual surface by wiping the real surface . in this way , they are provided immediate visual feedback as to the adequacy of their wiping action . once the cpu 110 determines the wiping coverage is adequate , it increments a cleaning “ score ” in block 2330 . the process continues to block 2335 where the cpu 110 compares the capacitive sensor values right after the wipe is completed with the baseline values retrieved in block 2305 . a uniform difference between all the sensors as determined by the cpu 110 indicates the presence of a liquid on the surface as determined in block 2340 . if no liquid is found to be present , the process adjusts the cleaning score accordingly in block 2341 and then proceeds to block 2380 where the cleaning score is compared with stored policy data . policy data is typically defined by a facility administrator in which the device is being used . for example , a hospital may choose to have a policy that the surface must be cleaned with a liquid . if no liquid was used then the process would determine that the cleaning was not adequate . the policy data may reside onboard the device 100 in the data memory 182 , or it may be stored external to the device and communicated via the communication interface 115 if liquid is detected in block 2340 the process moves to block 2345 where the cpu 110 measures the rate of evaporation of the liquid from the cleanable touch surface . it does this in an effort to determine the type of liquid used to clean the surface . some policies , for example , may dictate that a certain type of cleanser or disinfectant be used while others may allow only water . the cpu 110 ascertains , to the extent possible , what type of liquid was used during the wiping action . in one embodiment , the cpu 110 uses data from the capacitive sensors in the surface to determine the presence of moisture on the surface . moisture changes the capacitance of the surface , and can therefore be detected using the touch capacitive sensors in the surface . further , as the liquid evaporates from the surface , the capacitance on the surface changes accordingly and can be detected by a change in capacitance of the surface &# 39 ; s capacitive touch sensors . by measuring this change , the rate of evaporation is determined and correlated to various known cleaning liquids ( such as water and alcohol ). for example , the evaporation rate of alcohol is faster than that of water , and so the surface can tell the difference between water and alcohol . thus , using the evaporation rates of the cleaning liquid , the cpu 110 can determine what type of liquid was used to clean its surface . the rate at which a liquid evaporates is stored as “ evaporation signatures ” in the data memory sensor database 181 . the rate of evaporation can vary even for the same liquid from environment to environment . for example , most liquids will evaporate slower in a humid , cool environment than they will in a dry , hot environment . to accommodate for this variability , an embodiment of the present invention allows the user to calibrate the surface for the liquid being used and the environment in which it is being used . they do this by putting the device into a “ learn ” mode and then coat the surface with the liquid . the system then records the rate of evaporation of that liquid in that environment and stores it in the sensor database 1081 for reference in block 2350 of fig2 c . in another embodiment , a local humidity value is retrieved from a local or remote ( e . g ., website ) source via the communication interface 115 . the retrieved humidity value is then used by the cpu 110 to alter the stored evaporation rates . the process determines whether or not the liquid is a known cleanser in block 2355 of fig2 c . if it is a known cleanser , it adjusts the cleaning score accordingly in clock 2360 . if it is not a known cleanser then the cpu 110 determines if the liquid was water in block 2365 , and then adjusts the score accordingly in block 2370 ( for water ) and block 2375 for not water . in the case of block 2375 , it is an unknown liquid and a flag or warning can be issued prompting the user to identify the liquid and / or carry out a calibration so the cpu 110 can store the evaporation signature of the new liquid . the process continues to block 2380 where the cleaning score is compared with policies stored in user preferences data 182 , or alternatively retrieves the policy data from an external device via the communication interface 115 . it should be noted that the term “ cleaning score ” is used simply for illustrative purposes , and that in reality a more complex set of rules make up the algorithm that determines whether or not the cleaning has been adequate and meets the requirements of the stored policies . the process then exits at block 2385 . while the preferred embodiment of the invention has been illustrated and described , as noted above , many changes can be made without departing from the spirit and scope of the invention . accordingly , the scope of the invention is not limited by the disclosure of the preferred embodiment . instead , the invention should be determined entirely by reference to the claims that follow .
an intelligent touch - sensitive surface that is easy to clean , that self - monitors when it has become contaminated , and can discern when it has been cleaned . the surface incorporates a plurality of sensors that detect events that contribute to contamination and / or cleaning , including , but not limited to , detecting users &# 39 ; touches , movement of the surface , when liquid is present on the surface , when there has been a change of users , time passage since the last cleaning , and how well the surface was wiped . the surface then reports its cleaning status to software residing on a host computer , which in turn can transfer the information to a host server . in this way , the cleaning status of each surface can be monitored remotely and / or logged .