Patent Description:
The tethering of patients to healthcare systems creates many problems today. The leads connected to sensors are reused among various patients often causing infection, leading to even death in many cases. Wires also come in the way of clinicians and caretakers resulting in lower productivity, poorer quality of care and lower reliability as wires frequently come off. Furthermore, tethering is a major discomfort for patients, particularly when extended monitoring is involved. Due to these and many other reasons, it would be desirable to make healthcare monitoring systems totally wireless, thereby untethering patients from host systems.

There is a large installed base of a variety of host systems with tethered sensors - bedside patient monitors in hospitals and clinics; portable host devices for ambulatory monitoring (such as holter monitors). It is highly desirable to retrofit these legacy systems for wireless monitoring. For wireless monitoring to be widespread, the retrofitted wireless scheme must be able to compete with the wired systems in every way. The wireless link must be as reliable as a wire. The wireless sensors attached to the body must be ultra low cost, must dissipate very low power for multi day operation, and must be physically small and disposable. Furthermore, the wireless adaptor plugged into host system must be compact, low power, and low cost.

There have been recent attempts to create wireless systems some of which have been introduced in the market. However, all these systems have wireless sensors, host systems and adaptors which are bulky, high power, expensive and have questionable reliability. It makes them unsuitable to compete with wired solutions for large scale deployment. The invention described herein proposes a scheme to retrofit the existing wired systems for wireless operation based on integrated semiconductor solutions with attributes to compete with today's wired systems to meet the mass market needs. The proposed scheme transforms the wired system as shown in <FIG> to a wireless system in a transparent manner and without an impact on the core infrastructure of the system, including the host's hardware or software, also known as retrofitting.

<CIT> discloses a system comprising an ECG monitor, a base station for transmitting ECG signals to the ECG monitor and receiving the ECG signals from a body electronics unit by radio or other signals modulated with a carrier signal.

Provided herein is an apparatus which is defined in claim <NUM>.

Further provided herein is a method of retrofitting a wired healthcare system into a wireless healthcare system comprising the features of claim <NUM>.

Provided herein is a system for retrofitting a wired sensor system into a wireless sensor system by attaching an adapter device to the sensor system to be modified. Further provided herein is a method for retrofitting a wired system into a wireless system by connecting the sensor to the host system via a host bus without impacting the hardware or software of the system. The concept of retrofitting a wired healthcare system has been previously described in foreign application <CIT>, <CIT>, and <CIT>.

Provided herein is an apparatus for converting a wired sensor system to a wireless sensor system. The apparatus comprises a relay station comprising at least one antenna and at least one radio. The relay station is integrated as at least one application specific integrated circuit and further adaptable to convert a wired sensor system into a wireless sensor system. Furthermore, the relay station comprises a transcoder. The is adapted to demultiplex data received by the relay station, data to be sent to the relay station, or data communicated to the relay station. Additionally, the relay station can further comprise a host interface unit adaptable to transmit data from the relay station to a host device using a host device bus scheme. The host bus scheme can be selected from at least one of a universal serial bus (USB), a mini universal serial bus (mini USB), a secure digital, a mini secure digital, a peripheral component interconnect (PCI), a mini peripheral component interconnect (a mini PCI), an analog bus, or any suitable combination thereof. In some embodiments, the apparatus can further comprise a connector adaptable to communicate with a host device. The connector can comprise a bus adaptable to be in communication with the host device. The relay station can further comprise more than one radio. In addition, the relay station can be further adaptable to be in communication with a wireless patch adaptable be integrated with at least one application specific integrated circuit. The relay station is adapted to transmit data from a wireless sensor to a host device. The relay station can be further adaptable to transmit data from a host device to a wireless sensor. The relay station is adapted to use at least one host radio to wirelessly send data received from the sensors to a host having wireless connectivity with the relay station. The host radio can be adaptable to use at least one of radio scheme wherein the at least one radio scheme is selected from Wi-Fi, Bluetooth, ZigBee, wireless medical telemetry service (WMTS), medical implant communications service (MICS), a narrowband radio, or an ultrawideband radio.

Further provided herein is an apparatus for converting a wired sensor system to a wireless sensor system comprising: a relay station comprising at least one antenna, the relay station adaptable to convert a wired sensor system into a wireless sensor system; and at least two complementary radios, each complementary radio having an antenna. The at least two complementary radios are ultrawideband and narrowband radios. The two complementary radios are adaptable to operate in a low power mode and a high power mode. Furthermore, the at least two complementary radios are adaptable to operate in a short range mode and a high range mode. The relay station is adapted to be in communication with two different radios. The two complementary radios also make the wireless link reliable and robust through radio diversity. There is a high probability that one of the complementary radios will be operational when the other suffers an outage due to multipath fading or interference. The concept of complementary radio based communication has been previously described in a foreign application, <CIT>, <CIT>, and <CIT>.

<FIG> shows a wired healthcare or fitness system. The wired sensor system can comprise leads in communication with a patient and a host. The host can be stationary, portable, or mobile, or any combination thereof. The host can be in communication with the patient through a host bus. The host can further be in communication with an optional network and server. The wired system of <FIG> can be retrofitted for wireless operation as shown in <FIG> by using a wireless sensor system. <FIG> illustrates a wireless sensor system for use with a healthcare and/or fitness system. The wireless sensor system comprises patches, for example, micropatches (µpatches), as shown in the figure. The micropatches are in wireless communication with a relay station, indicated as microbase (µbase) in the figure. The microbase can be in communication with a host through a host bus. The host can be stationary, portable, or mobile, or any combination thereof. The host can then be in communication with an optional network and server. The system utilizes wireless sensors in the form of micropatches that are placed on the body of subject. The micropatches comprise the same type of basic sensors as used in the wired system. In addition, the micropatches comprise a radio system that can transmit the data to a base device as shown in <FIG>. The base is attached to the host device of the healthcare system that needs to be made wireless. Instead of using wired links between the patches and the base, the system can now wirelessly receive physiological data from a subject's body. This can provide the subject with increased mobility while providing the same functionality as a wired system.

Provided herein is a system for retrofitting a wired sensor system using application specific integrated circuts (ASIC). The invention disclosed herein further comprises micropatches and microbases using application specific integrated circuit (ASIC) devices. The use of ASIC with the system facilitates the economics and size/power advantages of semiconductor technology for large scale deployment. <FIG> is a graph illustrating the attributes of highly integrated ASIC technology for wireless solutions to compete with today's wired solutions. As shown in <FIG>, currently, reference points are established by wired solutions in terms of low cost and high link reliability for application capable of continuous monitoring. <FIG> also illustrates the combinations possible with standard radio chips, based on conventional radio chips combined with other chips to support sensor signal processing. The possible combination can require the use of many chips, which can make such combinations expensive, bulky, and/or requiring large amounts of power resulting in the need for a larger battery. Furthermore, wireless link reliability of conventional systems can be relatively low compared to conventional consumer grade radios which are not designed for sensitive healthcare applications. The combinations can not enable high volume applications served by wired solutions today.

Therefore, optimal solutions can be developed using highly integrated ASIC designs that can combine a high reliability robust radio with other needed functions including, but not limited to, sensor signal processing circuits. The architectures of micropatch ASIC and microbase ASIC can be been defined as a set. A high reliability radio is designed by asymmetrically distributing the cost and/or power between the micropatch ASIC and microbase ASIC. The requirements of the microatches can be more stringent than the requirements of the microbases. Using an ASIC chipset, it becomes possible to push the cost and power from the micropatch ASIC to the microbase ASIC. Technologies along these lines have been disclosed in the patent applications referenced herein.

<FIG> is illustrates a high level block diagram of an ASIC that can be used with a micropatch. The microbase or relay station can act as a bridge between the micropatch and the host device for retrofitting. The microbase can receive data from the microptach and can then rearrange the data as needed to present it to the host. The microbase can present the data to the host using the host bus, in the same way as the host was receiving data from the wired sensors (as shwon in <FIG>).

<FIG> illustrates one embodiment of a functional diagram of a relay station. The relay station can be largely implemented on an ASIC. The relay station can be in communication with the micropatches through a wireless link. In one embodiment, the relay station can be comprised of an antenna, a radio, a transcoder, and a host interface unit (I/F). A connector in communication with the relay station can also be in communication with a host. The connector can be in communication with the host through a bus. On one end of the base, the base can wirelessly communicates with the micropatches through at least one an antenna. Additionally, the base can communicate with the micropatches using at least one radio. The base can be designed to work with any suitable radio scheme including, but not limited to WiFi, Bluetooth, ZigBee, ultrawideband (UWB), medical implant communications service (MICS), wireless medical telemetry service (WMTS), any suitable narrowband radio, any other suitable standard or proprietary based radio, or combination thereof.

Traditional wired healthcare systems utilize sensors positioned on the body of a patient which are directly connected to a host device using wires. Traditional wired healthcare systems include electrocardiogram (ECG), electroencephalogram (EEG), and electromyogram (EMG) systems. In those systems, the host device accepts the analog signal that is detected by the sensors. The host typically accepts multiple such analogue signals in parallel from multiple leads. For example, ECG systems can use three, five, seven, or twelve leads. Therefore, the host device can an have an analog bus that can accept multiple parallel analog signals, or an analog lead for accepting a single analog signal. Wireless sensor systems, as provided herein, can use a digital radio to send the sensor data from the micropatches to the base. The analog signal from the sensor can be converted into a digital format through one or more analog to digital (A/D) converters. The digital data is then sent to the radio on the micropatch. The radio can then send the information from the sensor to the base. In some embodiments, the radio transmits the information from one sensor. In some embodiments, the radio transmits data from several body sensors to the base. The micropatch radio can multiplex several sensor signals using a multiplexing scheme, such as, time, frequency, or code multiplexing.

The data received by the base radio can then pass through a transcoder on the base. The transcoder can function to rearrange the data coming in at the antenna from the wireless connection in a manner that makes the data appear identical to the way the data would flow if using a wired sensor connected to the host device. For example, wired leads may feed the data to the host in a parallel fashion through certain connector device. In some embodiments of the wireless healthcare system, the data may be coming from equivalent wireless micropatches, in a multiplexed fashion over the radio link. In this case, the transcoder can collect the multiple equivalent signals from the micropatches that correspond to the multiple wired sensors of a wired system. The transcoder can then demultiplex the data, or perform any other suitable processing of the data, to convert it to parallel channels that are equivalent to the wired system. In summary, the transcoder will collect the data from the wireless micropatches through the radio as dictated by the radio protocol. The transcoder can then rearrange the data received from the micropatches into a format that the host is used to receiving when attached to wired leads. After the data has been rearranged, the transcoder can then send data to the host interface unit (host I/F), as shown in <FIG>. The transcoder can also have a digital-to-analog converter to convert the digital stream into one or more analog waveforms that are equivalent to a wired system. The parallel analog waveforms can be fed to the host using the same connector device that is used in the corresponding wired system.

A stand alone base with a built in radio can be used with a patch comprising a radio system that is different from the built-in radio connectivity of the wireless host device. The base is designed so that it connects two different radio systems together. The base can receive data from the micropatch using a radio that is compatible with the micropatches. The transcoder can decode and rearrange the received data in a manner consistent with the radio of the host device. The base can then retransmit the data to the host using a radio that is compatible with the device. Similarly, the data can also flow in a reverse path, from the host to the micropatches. The host I/F and connector in the base as shown in <FIG> become the radio system of the host device. The base can then communicate with two radio systems. For example, the radio system for the micropatches can be based on ultrawideband (UWB) or ZigBee and the radio system on the host device can be Bluetooth or WiFi.

The host I/F unit can then transmit the data to the host using the host's bus scheme. In some embodiments, the host bus can be a USB bus. The host bus can be any suitable bus including, but not limited to, USB, Mini USB, secure digital (SD), mini secure digital (Mini SD), PCI, Mini PCI, an analog bus, any suitable standard or proprietary wired bus, or any combination thereof. The data from the host I/F circuits can then flow to the host through an appropriate connector as shown in <FIG>. For example purposes only, in an embodiment where a USB bus is used, the connector will be the mechanical USB connector.

The micropatches can communicate with the base. In some embodiments, the base can communicate with the micropatches. The base can transmit information from the host to the micropatches in a seamless or transparent manner. The host device can initiate measurements in whatever manner the host device uses when wired electrodes are used. The relay device can detect such measurement initiation and send a command to the wireless sensor to start the measurement. The relay device can then get a response from the sensor and relay the response back to the host device. For example purposes only, a patient monitor in the hospital could initiate periodic pulse-oximetry measurements by sending signals through the wires to light LEDs of the pulse-oximetry device attached to a finger, and elicit a response from the photo detector in the device, which then comes back to the monitor through some other wire. The relay station of the device provided herein could then detect the start of such a measurement through its interface to the host device, and send a wireless command to the patch to light up light emitting diodes (LEDs) and collect a response from the photodetector. The response can then be sent back to the relay station, which can then relay the response to a montior. To the monitor the whole exchange between the base and the sensor would appear as if it had occurred through a wired system. Additionally, the components can perform their functions in reverse order.

The base shown in <FIG> can be implemented in a variety of ways. The base can be a dongle or a card that connects to the host device. Alternatively, the base can be a stand-alone module that has one or more cables with connectors that can then be plugged into the host device. The base can have its own power supply. Alternatively, the device can be powered by the host device through the one or more cables. The base can be a component of the host device, wherein the base is housed within the host device. The base can be a wireless stand alone module that connects the patches with the host device wirelessly. The base can exist in any suitable form for transferring data from the patches to the host device.

In some embodiments, the components of the base can comprise off-the-shelf devices. Alternatively, the components of the base can be integrated in an application specific integrated circuit (ASIC) chip.

Further provided herein is a system integrated as at least one application specific integrated circuit for converting a wired sensor system to a wireless sensor system comprising: a relay station adaptable to convert a wired sensor system to a wireless sensor system; and at least one wireless patch comprising a wireless sensor and at least one radio, wherein the relay station is adaptable to convert a wired sensor system to a wireless sensor system. The at least one wireless patch can further comprise an analog to digital converter. In some embodiments, more than one wireless patch can communicate with the relay station, the relay station adaptable to receive more than one signal. The radio can multiplex the more than one signal to transmit the signal.

Methods of detecting a signal are also provided herein. Disclosed is a method of detecting a signal using a wireless sensor system comprising: (a)detecting at least one signal from a signal source; (b) transmitting the signal in digital format to a relay station comprising at least one antenna and at least one radio, the relay station integrated as at least one application specific integrated circuit and further adaptable to convert a wired sensor system into a wireless sensor system; (c) processing the data received with the relay station; and (d) transmitting the processed data to a host device. The at least one signal can be an analog signal. The method can further comprise the step of converting the analog signal to a digital signal prior to the transmitting step. Additionally, the method can further comprise the step of converting the digital signal to an analog signal prior to the transmitting step.

Claim 1:
A wireless sensor system for monitoring a physiological parameter of a subject, comprising:
a host device configured to monitor a physiological parameter of a subject, the host device also being suitable for use in a wired sensor system in which sensors adapted to detect the physiological parameter and positioned on the body of a subject are directly connected to a host device using wires;
a relay station that is in communication with said host device, wherein the relay station is integrated as at least one application specific integrated circuit;
at least one wireless patch suitable for wireless communication with said relay station, wherein said wireless patch comprises a sensor for detecting said physiological parameter, and an application specific integrated circuit coupled to said sensor, wherein said wireless patch is adapted to detect data of the physiological parameter and said wireless patch is adapted to transmit said data to said relay station; and
at least two complementary radios for facilitating a wireless link between said relay station and said at least one wireless patch, each complementary radio having an antenna, wherein said at least two complementary radios are ultrawideband and narrowband radios, wherein said at least two complementary radios are adaptable to (<NUM>) operate in a low power mode and a high power mode or (<NUM>) operate in a short range mode and a high range mode,
wherein said relay station is adapted to receive said data from said wireless patch, rearrange said data as needed to present to said host device, and transmit said data to said host device, wherein the relay station further comprises a transcoder adapted to demultiplex said data received by the relay station from said wireless patch, wherein said transcoder is adapted to decode and rearrange said data received by the relay station to a format as needed to present to the host device,
wherein said relay station is configured to communicate with said host device using a built-in radio that is different from said at least two complementary radios, wherein the host device comprises a radio, and
wherein the application specific integrated circuit of the wireless patch and the application specific integrated circuit of the relay station are configured such that, in use, power is distributed asymmetrically between said application specific integrated circuit of said relay station and said application specific integrated circuit of said wireless patch.