Patent Description:
It is often useful to determine whether objects associated with a surgery are present in a patient's body before completion of the surgery. Such objects may take a variety of forms. For example, the objects may take the form of instruments, for instance, scalpels, scissors, forceps, hemostats, and/or clamps. Also, for example, the objects may take the form of related accessories and/or disposable objects, for instance, surgical sponges, gauzes, and/or pads. Failure to locate an object before closing the patient may require additional surgery, and in some instances, may have unintended medical consequences.

Accordingly, there is a need for a technology that is capable of providing both presence detection and tagged surgical item/implement identification functionality in the medical setting, as well as inventory controls of the tagged items/implements. Specifically, detecting the presence of, identifying, and maintaining inventory of tagged surgical items and materials that are used during the execution of a medical procedure. Technologies exist that enable these functions both individually as well as in conjunction with each other, but the methods and packaging of the discrete solutions used are not ideal for the application. More specifically, the components attached or affixed to the items being tracked are either too large physically and present nuisances or obstacles in the execution of the procedure, or the detection and identification performance of the solution may degrade rapidly in the presence of variable and uncontrolled dielectric or conductive materials.

Prior art documents useful for an understanding to the background of the invention include <CIT>, <CIT> and <CIT>.

Accordingly, there are needs for improvements in presence detection, tagged item identification, and inventory functionality in the medical setting.

This disclosure relates to systems for detection of surgical items and/or devices used in body cavities during surgery, specifically systems that include an antenna to be inserted directly into a surgical site to detect such surgical items and/or devices.

In accordance with the invention there is provided , an inventory system configured to detect and count potentially retained surgical items within a body of a patient includes a beacon tag configured to transmit a first return signal when energized, a signal generator configured to generate an energizing signal for the beacon tag, an antenna operably coupled to the signal generator, a processor, and a memory. The first return signal includes an electrical characteristic. The antenna is configured to receive the first return signal transmitted by the beacon tag. The memory includes instructions stored thereon, which when executed by the processor cause the system to energize the beacon tag by the energizing signal, receive the first return signal from the beacon tag by the antenna, and determine a presence of the beacon tag based on the electrical characteristic.

In an aspect of the present disclosure, the electrical characteristic may be a resonant frequency of the beacon tag.

In another aspect of the present disclosure, the electrical characteristic may be a ring-down decay rate of the beacon tag.

In yet another aspect of the present disclosure, the system may include an RFID tag configured to transmit a second return signal including the electrical characteristic when energized.

In a further aspect of the present disclosure, the instructions, when executed by the processor, may further cause the system to store a value of the electrical characteristic of the first return signal in the memory of the RFID tag.

In yet a further aspect of the present disclosure, the RFID tag may include a unique identifier, and the instructions, when executed by the processor, may further cause the system to associate the value of the electrical characteristic with the unique identifier.

In an aspect of the present disclosure, the instructions, when executed by the processor, may further cause the system to determine an identity of the potentially retained surgical item based on the association between the value of the electrical characteristic and the unique identifier.

In yet another aspect of the present disclosure, the system may further include a display. The instructions, when executed by the processor, may further cause the system to display the determined presence of the beacon tag on the display.

In a further aspect of the present disclosure, the instructions, when executed by the processor, may further cause the system to determine a quantity of potentially retained surgical items based on the first return signal.

In yet a further aspect of the present disclosure, the RFID tag may include at least one of a high frequency tag, or an ultra-high frequency tag.

In accordance with aspects of the disclosure, a computer-implemented method is provided for detecting and counting potentially retained surgical items within a body of a patient. The method includes energizing a beacon tag that is configured to transmit a first return signal, receiving the first return signal from an antenna, the antenna operably coupled to a signal generator, and determining a presence of the beacon tag based on the electrical characteristic. The first return signal includes an electrical characteristic when energized. The antenna is configured to receive the first return signal transmitted by the beacon tag.

In another aspect of the present disclosure, the electrical characteristic may be a resonant frequency of the beacon tag.

In yet another aspect of the present disclosure, the electrical characteristic may be a ring-down decay rate of the beacon tag.

In a further aspect of the present disclosure, the method may further include displaying the determined presence of the beacon tag on a display.

In yet a further aspect of the present disclosure, the method may further include transmitting a second return signal, by an RFID tag, the second return signal including the electrical characteristic when energized.

In a further aspect of the present disclosure, the method may further include storing a value of the electrical characteristic of the first return signal in the memory of the RFID tag.

In an aspect of the present disclosure, the RFID tag may include a unique identifier, and the method may further include associating the value of the electrical characteristic with the unique identifier.

In yet another aspect of the present disclosure, the method may further include displaying an identity of the potentially retained surgical item on a display based on the association between the value of the electrical characteristic and the unique identifier.

In another aspect of the present disclosure, the method may further include determining a quantity of potentially retained surgical items based on the first return signal.

In accordance with aspects of the disclosure, a non-transitory computer-readable medium is provided. The non-transitory computer-readable medium stores instructions which, when executed by a processor, cause the processor to perform a method for detecting and counting potentially retained surgical items within a body of a patient. The method includes energizing a beacon tag, the beacon tag configured to transmit a return signal including an electrical characteristic when energized, receiving the return signal from an antenna, the antenna operably coupled to a signal generator, the antenna configured to receive the return signal transmitted by the beacon tag, and determining a presence of the beacon tag based on the electrical characteristic.

In the drawings, identical reference numbers identify similar elements or acts. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not drawn to scale, and some of these elements are arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn are not intended to convey any information regarding the actual shape of the particular elements and have been solely selected for ease of recognition in the drawings.

Various aspects of the presently disclosed inventory systems are described hereinbelow with reference to the drawings.

In the following description, certain specific details are set forth in order to provide a thorough understanding of disclosed aspects. However, one skilled in the relevant art will recognize that aspects may be practiced without one or more of these specific details or with other methods, components, materials, etc. In other instances, well-known structures associated with transmitters, receivers, or transceivers have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the aspects.

Reference throughout this specification to "one aspect" or "an aspect" means that a particular feature, structure, or characteristic described in connection with the aspect is included in at least one aspect. Thus, the appearances of the phrases "in one aspect" or "in an aspect" in various places throughout this specification are not necessarily all referring to the same aspect. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more aspects.

<FIG> depicts a surgical environment "E" in which a medical provider <NUM> operates an inventory system <NUM> for detection and counting of beacon tags <NUM> and/or radio-frequency identification (RFID) tags <NUM> to ascertain the presence or absence of items, implements, or objects 100a (and, potentially, packaged surgical objects <NUM> one used) in a patient <NUM>. The inventory system <NUM> may include a signal generator <NUM> and an antenna <NUM> coupled to the signal generator <NUM> by one or more communication paths, for example, coaxial cable <NUM>. In one aspect of the inventory system <NUM>, the antenna <NUM> may take the form of a hand-held wand 110a.

The object 100a may take a variety of forms, for example, instruments, accessories, and/or disposable objects useful in performing surgical procedures. For instance, the object 100a may take the form of scalpels, scissors, forceps, hemostats, and/or clamps. Also, for example, the objects 100a may take the form of surgical sponges, gauze, and/or padding. The object 100a is tagged, carrying, attached, or otherwise coupled to an RFID tag <NUM>. Aspects of the inventory system <NUM> disclosed herein are particularly suited to operate with one or more RFID tags <NUM>, which are not accurately tuned to a chosen or selected resonant frequency.

In use, the medical provider <NUM> may position the wand 110a proximate the patient <NUM> in order to detect the presence or absence of the one or more RFID tags <NUM> and hence an object 100a. The medical provider <NUM> may, in some aspects, move the wand 110a along and/or across the body of the patient <NUM>. For a detailed description of an exemplary inventory system, reference may be made to commonly owned <CIT>.

The inventory system <NUM> may include a display <NUM> configured to display images and/or other data. The inventory system <NUM> may include an imaging device <NUM> configured to capture an image of an area, the area including at least a portion of a body of the patient <NUM>.

As seen in <FIG>, inventory system <NUM>, for detection and counting of surgical implements (e.g., object 100a) within a patient's body <NUM>, includes a signal generator <NUM> to provide an energizing signal for a beacon tag <NUM> and/or one or more RFID tags <NUM> affixed to an object 100a. Each RFID tag <NUM> is configured to transmit a return signal when energized, such that an antenna <NUM> can detect the return signal and confirm the presence of objects 100a within the body of patient <NUM>. The antenna <NUM> is operably coupled to the signal generator <NUM> via a communication cable <NUM>, which may be of variable length to provide greater range of motion to the clinician handling the antenna <NUM>. The signal generator <NUM> may include a controller <NUM>.

In one aspect of inventory system <NUM>, the antenna <NUM> is an antenna <NUM> configured to be waved over the surgical site <NUM>, e.g., over the body of patient <NUM>. As seen in <FIG>, for example, the antenna <NUM> may be held over the body of the patient <NUM> at the height of about four or about five inches while attempting to detect beacon tags <NUM> and/or RFID tags <NUM>, so that the user may detect and/or confirm the presence of objects 100a (and/or surgical object <NUM> once used in the surgical procedure) within the body of patient <NUM>.

As seen in <FIG> and <FIG>, the inventory system <NUM> may further include an RFID-enabled secure package <NUM> (e.g., RFID-enabled smart packaging and/or RFID enabled secure mutual authentication packaging), which includes an RFID tag <NUM> affixed thereto. For example, an RFID tag may be secured to a lid or a body of the RFID-enabled secure package <NUM>. The RFID tag <NUM> is configured to transmit a return signal when energized. Generally, the RFID-enabled secure package <NUM> will include an as-yet unused surgical object <NUM> configured to be removed from the RFID-enabled secure package <NUM>. The surgical object <NUM> includes a beacon tag <NUM> and/or a retained surgical item RFID tag, e.g., the RFID tag <NUM>, affixed to the surgical object <NUM>. The surgical object <NUM> may include, for example, any surgical sponge, cotton swab, instrument, tool, and/or device that is unintentionally left in the patient at the completion of a surgery or other procedure.

The RFID-enabled secure package <NUM> includes, but is not limited to, for example, caps and closures and are generally configured to verify the contents of sealed containers to ensure the product is genuine, not part of a recall, within the expiration date, and/or has not been tampered with or diverted. RFID-enabled secure package <NUM> generally includes a secure package RFID tag <NUM>.

In aspects, the retained surgical item RFID tag <NUM> may be linked to the secure package RFID tag <NUM> by embedding an encrypted block of data that contains the unique identifier of the RFID tag <NUM>. For example, to enable the use of the retained surgical object <NUM>, the RFID tag <NUM> may be scanned by the antenna <NUM> in the inventory system <NUM>.

<FIG> illustrates that controller <NUM> includes a processor <NUM> connected to a computer-readable storage medium or a memory <NUM>. The computer-readable storage medium or memory <NUM> may be a volatile type of memory, e.g., RAM, or a non-volatile type of memory, e.g., flash media, disk media, etc. In various aspects of the disclosure, the processor <NUM> may be another type of processor such as, without limitation, a digital signal processor, a microprocessor, an ASIC, a graphics processing unit (GPU), a field-programmable gate array (FPGA), or a central processing unit (CPU). In certain aspects of the disclosure, network inference may also be accomplished in systems that have weights implemented as memristors, chemically, or other inference calculations, as opposed to processors.

In aspects of the disclosure, the memory <NUM> can be random access memory, read-only memory, magnetic disk memory, solid-state memory, optical disc memory, and/or another type of memory. In some aspects of the disclosure, the memory <NUM> can be separate from the controller <NUM> and can communicate with the processor <NUM> through communication buses of a circuit board and/or through communication cables such as serial ATA cables or other types of cables. The memory <NUM> includes computer-readable instructions that are executable by the processor <NUM> to operate the controller <NUM>. In other aspects of the disclosure, the controller <NUM> may include a network interface <NUM> to communicate with other computers or to a server. A storage device <NUM> may be used for storing data.

Referring to <FIG>, beacon tag <NUM> generally includes an upper cover <NUM>, a lower cover <NUM>, an inductor <NUM>, and a capacitor <NUM>. The upper cover <NUM> and the lower cover <NUM> may both be constructed of a non-conductive material. The upper cover <NUM> and the lower cover <NUM> are configured to define a fluid tight cavity within which the inductor <NUM> and the capacitor <NUM> are retained. The inductor <NUM> generally includes a conductive wire 402a wrapped around a ferrite core 402b. The inductance of the inductor <NUM> is primarily determined by the ferrite core 402b, the number of turns of the conductive wire 402a around the ferrite core 402b, and a diameter (e.g., the gauge) of the conductive wire 402a. The capacitor <NUM> may be disposed below the inductor <NUM>. The capacitor <NUM> may be disposed on a lower portion of the lower cover <NUM>. The inductor <NUM> and the capacitor <NUM> form an L-C resonant circuit, which when energized resonate at a resonant frequency determined primarily by the capacitance and the inductance. Thus, the resonant frequency of beacon tag <NUM> may be calculated by <NUM>/(<NUM>* π * √ (L*C)), wherein "L" is the inductance, and "C" is the capacitance.

<FIG> shows a flow chart of an exemplary computer-implemented method <NUM> for detecting and counting potentially retained surgical items within a body of a patient in accordance with aspects of the present disclosure. Although the steps of <FIG> are shown in a particular order, the steps need not all be performed in the specified order, and certain steps can be performed in another order. For simplicity, <FIG> will be described below, with the controller <NUM> performing the operations. However, in various aspects, the operations of <FIG> may be performed in part by the controller <NUM> of <FIG> and in part by another device, such as a remote server. These variations are contemplated to be within the scope of the present disclosure.

The two main functions of an inventory system (such as an operating room safety system) are to detect and count potentially retained surgical items (RSIs). The term retained surgical item, as used herein, includes any surgical sponge, instrument, tool, and/or device that is unintentionally left in the patient at the completion of a surgery or other procedure. The disclosed technology detects and counts potential RSIs, each of which includes a beacon tag <NUM>, in a way that provides individual identification to each potential retained surgical item based on the beacon tag <NUM>.

Initially, at step <NUM>, the signal generator <NUM> energizes a beacon tag <NUM>, using an antenna <NUM>. The antenna <NUM> is configured to receive a return signal transmitted by the beacon tag <NUM>. In an aspect, the beacon tag <NUM> may be attached to a surgical object <NUM> (e.g., surgical gauze and/or a surgical sponge).

The return signal includes an electrical characteristic. The electrical characteristic may include a resonant frequency of the beacon tag <NUM> (e.g., about <NUM> or about <NUM> (<FIG>)). The beacon tag <NUM> may include a resonant L-C circuit that when energized, resonates at the resonant frequency of the L-C circuit. In aspects, the resonant frequency may be set by tuning the inductance or the capacitance of the L-C circuit, and/or the resonant frequency may be a byproduct of the manufacturing tolerances of the inductor and the capacitor used in the L-C circuit of the beacon tag <NUM>. For example, if the inductor <NUM> of the beacon tag <NUM> has a tolerance of about <NUM>% and the capacitor <NUM> of the beacon tag <NUM> has a tolerance of about <NUM>% then there may be a <NUM>% range on the resonant frequency. The resonant frequency of the L-C circuit may be tuned, for example, by changing the number of turns of conductive wire 402a on the inductor <NUM> (e.g., removing a turn of conductive wire 402a to decrease the inductance) and/or by changing the value of the capacitor <NUM> (<FIG>). In aspects, multiple beacon tags <NUM> may resonate at different frequencies when energized by the antenna <NUM>, each beacon tag <NUM> having a unique resonant frequency. At step <NUM>, the unique resonant frequency of each beacon tag <NUM> (<FIG>) may be measured in advance and stored in a memory <NUM> (or, for example, the memory of RFID tag <NUM>) and associated with a specific unique surgical object <NUM>.

In aspects, the electrical characteristic of the return signal includes a ring-down decay rate of the beacon tag <NUM>. After activation, the amplitude of the resonant frequency of the beacon tag <NUM> tends to decay over time (<FIG>). The decay over time of the amplitude of the resonant frequency is the ring-down decay rate of the beacon tag <NUM>. By tracking peak values of the return signal as it decays over time, the ring-down decay rate may be determined (e.g., by slope detection). Each unique beacon tag <NUM> has a unique ring-down decay rate (and/or slope) (<FIG>) and may be identified based on that unique ring-down decay rate. The ring-down decay rate of a particular beacon tag <NUM> may be stored in memory for later recall to identify that beacon tag <NUM>. In aspects, a mask with upper and/or lower limits, may be applied to a waveform of the return signal to enable determining if the return signal is from a beacon tag <NUM>.

In aspects, the inventory system <NUM> may include an RFID-enabled secure package <NUM> (e.g., smart packaging), which includes a set of manufactured potential RSIs <NUM> (such as cotton sponges). The RFID-enabled secure package <NUM> includes an RFID tag <NUM> (e.g., an RFID chip), which is capable of mutual authentication with a host (e.g., controller <NUM>). The RFID tag <NUM> on the potential RSIs <NUM> may include a unique identifier.

Next, at step <NUM>, the controller <NUM> receives the return signal from the antenna <NUM>, which is configured to receive at least one return signal transmitted by the beacon tag <NUM>. At step <NUM>, the return signal may be compared to stored data representing the electrical characteristic of the beacon tag <NUM>. If the stored data and the return signal include the same value electrical characteristic, the processor may determine an identity of a specific unique surgical object 100a, <NUM>.

In aspects, the antenna <NUM> may include a sensor <NUM> (e.g., a gyro and/or a GPS), which is configured to provide localization-based data of the antenna <NUM> when scanning for the beacon tag <NUM>. The spatial parameter may further include a proximity of the antenna <NUM> to a patient <NUM>. The spatial parameter may be used to help determine the presence and/or location of a beacon tag <NUM>.

Next, at step <NUM>, the controller <NUM> determines a presence of the beacon tag <NUM> based on the electrical characteristic.

It is contemplated that the display <NUM> may be incorporated into the antenna <NUM>, within a directly connected base station box, and/or may utilize a remotely connected display such as a remote screen or tablet.

In aspects, the processor may determine a quantity of potentially retained surgical objects <NUM> based on the presence of one or more the beacon tags <NUM>. The quantity and the identity of each of the beacon tags <NUM> and/or surgical objects may be displayed.

In an aspect, an RFID tag <NUM> may be attached to the surgical object <NUM>. The RFID tag <NUM> may include a high-frequency RFID tag, a low-frequency RFID tag, and/or an ultra-high frequency RFID tag. The RFID tag may include a unique identifier configured for identifying unique surgical objects. The processor may associate the value of the electrical characteristic with the unique identifier. The processor may determine an identity of the potentially retained surgical object <NUM> based on the association between the value of the electrical characteristic and the unique identifier. For example, the unique identifier may be a serial number of the RFID tag <NUM> which may be associated with a resonant frequency (of about <NUM>) of the beacon tag <NUM> to identify a unique surgical sponge. The processor may display the determined identity of the potentially retained surgical item on a display <NUM> (<FIG>).

Claim 1:
An inventory system (<NUM>) configured for detecting and counting potentially retained surgical items within a body of a patient, the inventory system comprising:
a beacon tag (<NUM>) configured to transmit a first return signal when energized, the first return signal including an electrical characteristic;
a signal generator (<NUM>) configured to generate an energizing signal for the beacon tag;
an antenna (<NUM>) operably coupled to the signal generator, the antenna configured to receive at least the first return signal transmitted by the beacon tag;
a processor (<NUM>) ; and
a memory (<NUM>) , including instructions stored thereon, which when executed by the processor cause the inventory system to:
energize a beacon tag by the energizing signal;
receive the first return signal from the beacon tag by the antenna; and
characterised by determining a presence of the beacon tag based on a comparison of a stored electrical characteristic with that of the return signal.