Abstract:
A wearable haptic device includes (a) substrate having provided thereon a fastener (e.g., adhesive) for attachment to a user; (b) one or more EMP transducers attached to the substrate, such that a mechanical response in each EMP transducer may provide a haptic response of sufficient magnitude to be felt by the user; and (c) control circuit controlling the vibration frequency, the time of operation and the duration for each activation of the EMP transducer. The wearable haptic device may include a wireless communication circuit (e.g., Bluetooth transceiver) for receiving message from an external device (e.g., smartphone). The control circuit interprets message received and according to the interpreted message provides an electrical stimulus to cause the mechanical response of the EMP transducer. The EMP transducer may also serve as a sensor, such that a mechanical stimulus on the EMP transducer provides an electrical response that is detected by the control circuit.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to wearable wireless devices. In particular, the present invention relates to wearable wireless devices using electromechanical polymer (EMP) transducers as sensors and actuators. 
     2. Discussion of the Related Art 
     Existing “wearable” devices reveal that most devices are developed for the following categories of applications: information-entertainment, fitness-wellness, and health-medical. 
     Users of wireless devices rely on the wireless devices for many applications, including messaging, voice calls, texting, time check, music, gaming, social media, camera, alerts, alarms, calendar, web browsing and searches. In many of these applications, the amount of information being transmitted to a user or received from a user is relatively small. Nevertheless, for the most part, sending or receiving such small amount of information still requires the user to reach for the wireless device. Therefore, efficient hands-free operations for many of these applications are highly desirable. 
     To address some of these needs, many types of wearable devices have been developed. For the most part, these wearable devices are quite expensive, have very limited applications, are bulky and are not attractive to wear. 
     SUMMARY OF THE INVENTION 
     According to one embodiment of the present invention, a wearable haptic device includes (a) a substrate having provided thereon a fastener (e.g., an adhesive) for attachment to a user; (b) one or more EMP transducers attached to the substrate, such that a mechanical response in each EMP transducer may provide a haptic response of sufficient magnitude to be felt by the user; and (c) a control circuit controlling the vibration frequency, the time of operation and the duration for each activation of the EMP transducer. In one embodiment, the wearable haptic device further includes a wireless communication circuit (e.g., a Bluetooth transceiver) for receiving a message from an external device (e.g., a smartphone). The control circuit interprets the message received and according to the interpreted message provides an electrical stimulus to cause the mechanical response of the EMP transducer. 
     According to one embodiment of the present invention, the wearable haptic device may serve as a bandage. The EMP actuators may provide vibration at different frequencies and intervals. The frequencies and intervals may be programmed during manufacturing and customized, if necessary, for the bandage in the field. Such a bandage may be particularly effective in treating ulcerated tissues or it may enhance blood flow and the exchange of oxygen. 
     According to one embodiment of the present invention, the EMP transducer may also serve as a sensor, such that a mechanical stimulus on the EMP transducer provides an electrical response that is detected by the control circuit. The wearable haptic device may include amplification circuitry for conditioning the electrical stimulus or response between the control circuit and the EMP transducer. The control circuit may create a message based on the detected electrical response from the EMP transducer and may send the message via the wireless communication circuit to the external device. 
     The present invention is better understood upon consideration of the detailed description below in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1( a )  is a block diagram of haptic patch  100 , in accordance with one embodiment of the present invention. 
         FIG. 1( b )  shows an exemplary external appearance of haptic patch  100 , in accordance with one embodiment of the present invention. 
         FIG. 2  shows exemplary system  200  in which haptic patch  100  may be deployed in accordance with one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention takes advantage of the properties of thin electromechanical polymer (EMP) transducers to create wearable devices that provide, when activated, haptic response to the wearer and to provide sensing signals from the wearer to a local or remote signal processing device. EMP transducers have been disclosed, for example, in copending U.S. patent application (“Copending Application”), Ser. No. 13/683,963, entitled “Localized Multimodal Electromechanical Polymer Transducers,” filed Nov. 21, 2012. The disclosure of the Copending Application is hereby incorporated by reference in its entirety. 
     In one embodiment, an EMP transducer may be incorporated on a small patch (“haptic patch”) which may be fastened or attached by adhesive, for example, onto the skin of the wearer, his clothing or another wearable close to the wearer&#39;s body (e.g., as a pendant or provided on a pendant to be worn with a necklace). The haptic patch may be used, for example, as a wound dressing, or be attached on a wound dressing. As a wound dressing, the haptic patch is attached directly to a wound. The haptic patch may have an external protective wrapping or substrate that may be provided, for example, in a form similar to those patches used for delivering transdermal medication. As an actuator, the EMP transducer may provide a mechanical stimulus (e.g., a vibration) at the wearer&#39;s skin of suitable frequency content or strength (e.g., 25-250 Hz, or any other frequency, including ultrasound frequencies). Alternatively, the frequency content or strength of the mechanical stimulus may encode a predetermined message to the wearer. As a sensor, the wearer may cause sensing signals (e.g., by applying pressure) to be sent from the EMP transducer. In this manner, the wearer may exchange any of a large number of tangible emotions and silent messages with others.  FIG. 1( a )  is a block diagram of haptic patch  100 , in accordance with one embodiment of the present invention.  FIG. 1( b )  shows an exemplary external appearance of haptic patch  100 , in accordance with one embodiment of the present invention. 
     As shown in  FIG. 1 , haptic patch  100  includes power source  101  (e.g., a conventional or solar-charged battery), ultra-low power wireless communication device  102  (e.g., a Bluetooth transceiver with antenna), controller  103 , amplifier  104 , and EMP transducer  105 . Power source  101  may supply, for example, a 0.4 watts, 150-volt voltage source for use with EMP transducer  105 . Under control of controller  103 , amplifier  104  may provide an electrical stimulus that activates a mechanical response in EMP transducer  105 . Alternatively, when a mechanical stimulus is impressed on EMP transducer  105 , an electrical response is provided on EMP transducer  105 . Amplifier  104  may amplify the electrical response to a suitable signal level to allow controller  103  to capture the electrical response. Amplifier  104  may include not only circuitry for amplification or attenuation, but also circuitry for providing and conditioning signals so as to be compatible with signal requirements of EMP transducer  105  and controller  103 , such as an analog-to-digital converter and a digital-to-analog converter. As discussed above, by suitable use of frequency and mechanical or electrical signal strengths, many types of messages may be sent to or received from haptic patch  100 . 
       FIG. 2  shows exemplary system  200  in which haptic patch  100  may be deployed, in accordance with one embodiment of the present invention. As shown in  FIG. 2 , wearer  201  has a haptic patch (e.g., haptic patch  100 ) attached to a location of his body which is sensitive to haptic responses. The existing EMP transducer technology allows such a location to be practically any location on the approximately two square meters of skin on a typical human adult. Through the on-board ultra-low power wireless communication device  102 , a communication link is maintained between haptic patch  100  and wireless mobile device  202  (e.g., a smartphone), which is also connected to wireless communication network  203  (e.g., a cellular telephone network). Of course, haptic patch  100  is not limited to having just one EMP transducer; in fact, having multiple EMP transducers may allow haptic patch  100  to provide many additional effects not available to a haptic patch having a single EMP transducer. 
     During operation, for example, controller  103  communicates via ultra-low power wireless communication device  102  with wireless mobile device  201 . Another user (e.g., a user of wireless mobile device  204 ) may send a message to wireless mobile device  202 , which is intercepted by an application program running on wireless mobile device  202 . For example, the application may recognize the message from the sender to be a request providing a gentle reminder tap to wearer (e.g., to reminder the wearer of the patch to take a scheduled dose of medication). Wireless mobile device  202  then invokes an appropriate command in controller  103  to actuate EMP transducer  105  to deliver the intended gentle tap. In the opposite direction, for example, EMP transducer  105 , acting as a mechanical sensor, may provide a stream of electrical signals read periodically by controller  103 . The stream of electrical signals may be interpreted by wireless mobile device  202  as, for example, measurements of blood pressure, heart rate or temperature. Wireless mobile device  202  may transmit the result, for example, to an interested party at wireless mobile device  204  (e.g., an emergency response team). 
     Patch  100  may be provided at minimal cost (e.g., less than $10) and operates substantially hands-free. As the cost is relatively low, patch  100  may be provided as a disposable device, desirable for reasons of hygiene. Patch  100  may also be provided by a large number of inexpensive materials, which can be colored or textured to achieve a very attractive external packaging. 
     In many applications, each patch may be associated uniquely with a single sender so that the sender and the wearer may agree on their private encoding of the haptic response (e.g., a gentle tap on a first patch associated with one&#39;s mother may have a different meaning than the same gentle tap on a second patch associated with one&#39;s significant other). Many encodings of suitable emotions may be expected. For example, different activations of EMP transducer  105  may encode, patting, giggle, encouragement, agitation, anger, fear, excitement, and intimacy (e.g., kiss, “you are in my thoughts right now,” and arousal). Many encodings of silent messages are similarly possible. For example, different activations of EMP transducer  105  may encode a task reminder, an indication of readiness to act in concert, silent agreement or disagreement with a colleague during a negotiation session, and turn-by-turn directions. A user may select the message from an application program (or “App”) running on a wireless mobile device (e.g., wireless mobile device  204 ), which would send instructions to the haptic patch to activate the corresponding software routines running on controller  103  to effectuate the haptic response or responses conveying the selected message. In some embodiments, the user may customize the haptic responses for a message by associating and orchestrating one or more haptic responses to that message. (Here, orchestrating refers to setting certain parameters of the haptic response, such as duration, delay, frequency, and strength). 
     In the case where multiple EMP transducers are provided, the EMP transducers may be activated in concert, for example, to convey directionality. Alternatively, the alternating activation of two EMP transducers creates a “blinking” sensation that may be used to represent a message appropriately expressed by such a blinking sensation. The EMP transducers may have structural differences that allow each EMP transducer to specialize in a particular modality or force regime. For example, one EMP transducer may be used to provide vibrational haptic responses, while another EMP transducer may be used to provide deformation-based haptic responses and while a third EMP transducer may provide an audio response. 
     Activation of a haptic response need not be controlled by wireless remote control. For example, a haptic patch may be programed to provide stretching or to provide vibration or massage for a predetermined time (e.g., two hours) on the skin to which the haptic patch is attached. The programmed operation may be initiated or stopped, for example, by a predetermined mechanical stimulus provided by the user on the patch. 
     The haptic patch may also be used as a programmable active bandage or dressing. It is known that ulcerated tissue may benefit from vibrations that promote oxygen exchange and that enhance blood flow. Certain vibrational frequencies and treatment intervals may be programmed for this application. The haptic patch provides a low-cost, location-specific device and does not require administration by a trained practitioner, unlike conventional ultrasound equipment, which also requires a substantial capital investment. The haptic patch also avoids the whole body vibration treatment in the prior art, which is administered by placing the patient on a vibrating platform for a prescribed time period. 
     The detailed description above is provided to illustrate specific embodiments of the present invention and is not intended to be limiting. Numerous modifications and variations within the scope of the present invention are possible.