Metal detection device and its operating method

Abstract

Disclosed are methods and devices for detecting residual surgical objects or other objects having magnetic signatures within a patient's body. The device can include a handle, a shaft extending from the handle, and a distal sensing portion positioned distal to the shaft. The distal sensing portion can include one or more gradiometers including multiple magnetometers. The device can further include one or more output components configured to generate a user output that notifies a user of the detected object.

Description

Technical Field

[0001] (Cross - Reference to Related Applications)

[0001] This application claims the benefit of U.S. Provisional Application No. 62 / 900,385, filed on September 13, 2019, and U.S. Provisional Application No. 62 / 927,702, filed on October 30, 2019. These are hereby incorporated by reference in their entirety. This application also incorporates by reference U.S. Patent Application Publication No. 2017 / 0347915, published on December 7, 2017.

[0002]

[0002] The present disclosure generally relates to the field of metal detection based on magnetometers, and more specifically, to an improved magnetometer - based metal detector for detecting residual surgical articles in a patient's body, such as sharps, or sponges with RFID tags, metal implants, metal wires, and other objects having a magnetic signature.

Background Art

[0003]

[0003] Surgeons and other operating room (OR) specialists spend a significant amount of time and resources identifying the location of retained surgical items (RSIs), such as lost surgical needles, broken parts of surgical instruments, or other types of sharp objects, within a patient's body. With the increasing use of minimally invasive laparoscopic and robotic procedures, it has become even more difficult for surgeons to locate lost surgical needles, broken instruments, and other types of sharp objects and fragments. Retained objects can pose serious risks to the patient, including potential chronic pain or organ damage. As a result, surgeons and other OR specialists spare no effort to ensure that all tools and instruments have been accounted for. However, with an average of 300 tools handled per surgery, multiple staff rotations, and the potential for instrument parts to become detached, the search for RSIs has become more common. According to one study, 63.8% of all surgeons surveyed experienced a surgical needle loss event during minimally invasive surgery in the past 12 months. Additionally, 89.6% of the surgeons surveyed reported 1 to 5 surgical needle loss incidents during their careers. Furthermore, in over 13% of cases, it took more than 30 minutes to locate and retrieve the lost surgical needle, and in 3% of cases, the surgeon was unable to retrieve such a needle after searching. See Jayadevan, Rajiv, et al., "A protocol to recover needles lost during minimally invasive surgery." JSLS: Journal of the Society of Laparoendoscopic Surgeons vol. 18,4 (2014).

[0004]

[0004] Often, surgeons and other OR specialists initially rely on visual searches for metallic RSI such as surgical needles, sharp objects, and broken tools. If the item is not found, the OR staff spends additional time searching, usually with the patient receiving an X-ray scan and more anesthesia being administered. As a result, radiation exposure to the patient and staff increases, and the risk of complications due to long anesthesia times rises. If the surgeon is ultimately unable to locate the position of the lost surgical needle or sharp object, patient disclosure is required, and both the hospital and the surgeon risk damage to their reputations or litigation. Additionally, RSI events are not compensable, and the hospital bears the burden of the cost of further procedures or mediation.

[0005]

[0005] Conventional metal detection devices often do not have the ability to accurately determine the precise location of metallic RSI within a patient's body with high precision. Also often, such devices are not suitable for in vivo detection, are not portable, and cannot be easily rotated to navigate within tortuous anatomical structures. Further, such conventional metal detection devices cannot adequately remove the effects of background magnetic field interference or can only remove such interference using rudimentary point measurement or subtraction algorithms that risk inaccurate detection.

[0006]

[0006] Accordingly, solutions are needed to address the above-mentioned drawbacks and inconveniences. Such solutions must be portable and allow surgeons to easily move and rotate the device within the patient's body. Also, such solutions must not be overly complex, be cost-effective, and be easy to manufacture.

Summary of the Invention

[0007]

[0007] Disclosed are a magnetometer-based metal detector, a metal detection system, and a method of operating the same for detecting metallic objects (such as RSI, metal implants, metal wires, etc.) within a patient's body. In one aspect, a metal detection device is disclosed that includes a handle, a shaft extending from the handle, and a distal sensing portion positioned distally on the shaft. The distal sensing portion may include a proximal gradiometer including a first proximal magnetometer and a second proximal magnetometer, and a distal gradiometer including a first distal magnetometer and a second distal magnetometer. The metal detection device may also include an output component configured to generate a user output to notify the user about the detected object, and a microcontroller including one or more processors and a memory unit. The one or more processors may be programmed to execute instructions stored in the memory unit to calculate a differential signal from magnetic field measurements obtained from the first proximal magnetometer, the second proximal magnetometer, the first distal magnetometer, and the second distal magnetometer. The one or more processors may be programmed to execute another instruction to apply at least one of a signal filter and a differentiation to the calculated differential signal to obtain a detection signal.

[0008]

[0008] The signal filter may include a high-pass filter and a low-pass filter (such as a second-order or two-pole filter). For example, the high-pass filter can remove drift and offset and return the average signal to zero. The low-pass filter or second-order filter (also referred to as a two-pole filter) can more aggressively cut off high-frequency noise. For example, the high-pass filter may have a cut-off of 5.5 Hz, and the low-pass filter may have a cut-off of 10 Hz.

[0009]

[0009] The one or more processors may be programmed to execute another instruction to compare the detection signal with a threshold and, if the detection signal exceeds the threshold, instruct the output component to generate a user output.

[0010]

[0010] Further, in another mode, to disable the threshold for a given level, or for a given time period, or for a given product, the threshold is removed or set below zero so that the sound or tone is always on, and it is also possible for the tone and / or light to test the frequency and / or intensity as the signal increases and decreases. This mode may make it possible to observe signals below the threshold for response.

[0011]

[0011] The first proximal magnetometer, the second proximal magnetometer, the first distal magnetometer, and the second distal magnetometer can be two-axis magnetometers. The first proximal magnetometer, the second proximal magnetometer, the first distal magnetometer, and the second distal magnetometer can each have an x-axis and a y-axis. Each of the first proximal magnetometer and the second proximal magnetometer can include at least a +x-axis and a +y-axis. The +x-axis of the first proximal magnetometer can be oriented in the opposite direction to the +x-axis of the second proximal magnetometer. The +y-axis of the first proximal magnetometer can be oriented in the opposite direction to the +y-axis of the second proximal magnetometer.

[0012]

[0012] Each of the first distal magnetometer and the second distal magnetometer can include at least a +x-axis and a +y-axis. The +x-axis of the first distal magnetometer can be oriented in the opposite direction to the +x-axis of the second distal magnetometer. The +y-axis of the first distal magnetometer can be oriented in the opposite direction to the +y-axis of the second distal magnetometer.

[0013]

[0013] Each of the second distal magnetometer and the first proximal magnetometer can include at least a +x-axis and a +y-axis. The +x-axis of the second distal magnetometer can be oriented in the opposite direction to the +x-axis of the first proximal magnetometer. The +y-axis of the second distal magnetometer can be oriented in the opposite direction to the +y-axis of the first proximal magnetometer.

[0014]

[0014] In some variations, the axes of the first proximal magnetometer and the second proximal magnetometer can be aligned with or orthogonal to the axes of the first distal magnetometer and the second distal magnetometer.

[0015] Reference is made to each of the magnetometers or magnetic sensors including the x-axis (e.g., the +x axis) and the y-axis (+y axis). In the present disclosure, however, the reference to the x-axis (e.g., the +x axis) or the y-axis (+y axis) may be considered to also indicate a uniaxial magnetometer having only the x-axis or the y-axis for the magnetometer or magnetic sensor. Thus, the reference to four two-axis magnetometers can also apply to eight one-axis magnetometers.

[0016]

[0016] In other variations, at least one of the axes of the first proximal magnetometer and the second proximal magnetometer may not be orthogonal to (or may be angled obliquely to) at least one of the axes of the first distal magnetometer and the second distal magnetometer. For example, the distal sensing unit may include a proximal rigid printed circuit board (PCB), a distal rigid PCB, and a distal flexible circuit disposed between the proximal rigid PCB and the distal rigid PCB and connecting the proximal rigid PCB to the distal rigid PCB. The first proximal magnetometer and the second proximal magnetometer may be coupled to the proximal rigid PCB. The first distal magnetometer and the second distal magnetometer may be coupled to the distal rigid PCB. The distal rigid PCB may be rotationally angled by a twist angle with respect to the proximal rigid PCB about the distal flexible circuit. In some variations, the twist angle can be about 45 degrees. In other variations, the twist angle can be about 60 degrees or about 30 degrees.

[0017]

[0017] The distal sensing unit can be covered with a sensor housing. The sensor housing may have a housing diameter. The housing diameter can be between about 3.0 mm and about 10.0 mm. For example, the housing diameter can be about 5.0 mm. Also, the sensor housing may have a housing length dimension between about 40.0 mm and about 50.0 mm.

[0018]

[0018] In some variations, the microcontroller can be housed within the handle. The distal sensing unit may further include one or more operational amplifiers. The one or more operational amplifiers may be configured to amplify the raw output signal from at least one of the first proximal magnetometer, the second proximal magnetometer, the first distal magnetometer, and the second distal magnetometer before such signal is sent to the analog-to-digital converter (ADC) or ADC component of the microcontroller within the handle.

[0019]

[0019] Further, the metal detection device may further include a flexible portion that couples or connects the distal sensing unit to the shaft. The flexible portion is bendable and may include a straight configuration and a bent configuration. When the flexible portion is in the bent configuration, the distal sensing unit may be positioned closer to the shaft. The flexible portion may be partially made of a thermoplastic elastomer. For example, the flexible portion can be partially made of Pebax®.

[0020]

[0020] The handle may further include a trigger configured to control the bending of the flexible portion. The trigger may be connected to the flexible portion by a pull cable that extends through the shaft and the flexible portion. Pulling the trigger can pull the pull cable to bend the flexible portion towards the shaft.

[0021]

[0021] The handle may further include a trigger potentiometer coupled to the trigger. One or more processors of the microcontroller can be programmed to execute instructions for determining the trigger speed based on data obtained from the trigger potentiometer.

[0022]

[0022] The shaft can be rotatable about the longitudinal axis of the shaft. The handle may also include a clock ring coupled to the shaft. The shaft can be rotatable in response to the rotation of the clock ring.

[0023]

[0023] The handle may further include a lock ring. The lock ring may include a plurality of lock splines configured to obstruct the rotation of the clock ring. The clock ring can be configured to be released from the lock splines of the lock ring by being pushed in the distal direction. The clock ring may become rotatable after being pushed in the distal direction.

[0024]

[0024] The metal detection device may further include a test rod configured to move in parallel into and retract out of a sensor housing covering the distal detection portion. The functionality of the metal detection device can be verified using the test rod. In some variations, the test rod may be partially made of ferromagnetic metal.

[0025]

[0025] The test rod may be partially housed within a spring tube. The spring tube may extend through a shaft and a flexible portion coupling the shaft to the distal detection portion. The flexible portion may be bendable such that when a trigger on the handle is pulled, the distal end of the flexible portion bends toward the shaft. The spring tube can be configured to bias the flexible portion to return to an unbent configuration when the trigger is released.

[0026]

[0026] The spring tube can be partially made of a thermoplastic material. For example, the spring tube may be partially made of polyethylene terephthalate.

[0027]

[0027] The handle may further include a test bar slider. The test bar slider may be configured to be actuated distally or proximally to axially translate the test bar within the shaft. The handle may also include a slider potentiometer coupled via a gear to a part of the test bar slider. One or more processors of the microcontroller can be programmed to execute another instruction for determining the slider position based on data obtained from the slider potentiometer. The slider position can indicate the relative positioning of the test bar with respect to at least one of a first proximal magnetometer, a second proximal magnetometer, a first distal magnetometer, and a second distal magnetometer.

[0028]

[0028] One or more processors of the microcontroller can be programmed to execute another instruction for adjusting a threshold when the test bar is positioned in proximity to at least one of a first proximal magnetometer, a second proximal magnetometer, a first distal magnetometer, and a second distal magnetometer, for testing the operability or functionality of the metal detection device.

[0029]

[0029] The handle may include a sensitivity wheel. One or more processors of the microcontroller can be programmed to execute another instruction for adjusting a threshold in response to rotation of the sensitivity wheel. The handle may further include a sensitivity rotary potentiometer coupled to the sensitivity wheel. One or more processors of the microcontroller can be programmed to execute an instruction for determining the wheel rotation direction based on data obtained from the sensitivity rotary potentiometer.

[0030]

[0030] One or more processors of the microcontroller can be programmed to execute another instruction for applying a signal filter or differentiation to the calculated differential signal based on the wheel rotation direction. One or more processors of the microcontroller can be programmed to execute an additional instruction for adjusting a threshold based on the wheel rotation direction.

[0031]

[0031] In some embodiments, one or more processors of the microcontroller can be programmed to execute another instruction for applying both a signal filter and differentiation to the calculated differential signal based on the wheel rotation direction. One or more processors of the microcontroller can be programmed to execute additional instructions for adjusting a threshold value based on the wheel rotation direction.

[0032]

[0032] The distal sensing unit may further include an inertial measurement unit (IMU) including a three-axis accelerometer and a three-axis gyroscope. In some embodiments, it is also possible to accommodate the IMU within the handle. One or more processors of the microcontroller can be programmed to execute another instruction for adjusting a threshold value based on the acceleration data obtained from the three-axis accelerometer and the rotation data obtained from the three-axis gyroscope.

[0033]

[0033] The distal sensing unit includes a distal light-emitting diode (LED), and the handle may include a proximal LED. At least one of the distal LED and the proximal LED is an example of an output component, and the light emitted by at least one of the distal LED and the proximal LED can be an example of user output.

[0034]

[0034] The handle may include a speaker. The speaker can be another example of an output component. The sound (e.g., beep sound) transmitted by the speaker can be an example of user output.

[0035]

[0035] The distal sensing unit can be housed within a sensor housing. The sensor housing and the shaft can be made of a biocompatible material to enable in-vivo detection within the patient's body.

[0036]

[0036] The shaft can be partially made of stainless steel. The sensor housing can be partially made of at least one of titanium and polymer material. In other variations, the sensor housing can be partially made of aluminum or an aluminum alloy.

[0037]

[0037] At least one of the first proximal magnetometer, the second proximal magnetometer, the first distal magnetometer, and the second distal magnetometer can be an anisotropic magnetoresistance (AMR) sensor. The first proximal magnetometer can be separated from the second proximal magnetometer by a proximal magnetometer separation distance. The proximal magnetometer separation distance can be between about 4.00 mm and 5.00 mm.

[0038]

[0038] The first distal magnetometer can be separated from the second distal magnetometer by a distal magnetometer separation distance. The distal magnetometer separation distance can be between about 4.00 mm and 5.00 mm.

[0039]

[0039] The second distal magnetometer can be separated from the first proximal magnetometer by a gradiometer separation distance. The gradiometer separation distance can be between about 18.00 mm and 20.00 mm.

[0040]

[0040] The handle can be sized such that it can be gripped with one hand.

[0041]

[0041] In some variations, the detected object can be a surgical suture needle. Also, the detected object can be part of a metallic surgical instrument. Further, the detected object can be at least one of a sponge with an RFID tag and a sponge with a metallic mark. The distal detection unit can further include an RFID reader configured to read an RFID tag embedded within the sponge with the RFID tag.

[0042]

[0042] The detected object can be at least one of a ferromagnetic tag or a non-ferromagnetic medical device tagged with a plate. Also, the detected object can be at least one of a surgical wire, a guide wire, and an intravascular wire. The detected object can be a stent, a vascular scaffold, or a combination thereof.

[0043]

[0043] The metal detection device can also include a conductive element extending from at least one of the distal sensing portion and the shaft. A link cable can be electrically coupled to the conductive element. The link cable can extend out from the handle of the metal detection device. The link cable can be coupled to a closed-circuit indicator.

[0044]

[0044] Disclosed is a metal detection system comprising a magnetic blanket configured to cover a portion of a patient's body and a metal detection device disclosed herein. As previously discussed, the metal detection device can include a handle, a shaft extending from the handle, and a distal sensing portion including a plurality of magnetometers. The distal sensing portion can be covered with a sensor housing.

[0045]

[0045] The metal detection device can further include an output component configured to generate a user output to notify the user about the detected object based on magnetic field measurements obtained from the plurality of magnetometers. At least one of the shaft and the sensor housing can be configured to be inserted into a portion of the patient's body when a portion of the body is covered with the magnetic blanket.

[0046]

[0046] Also disclosed is a method for detecting a magnetic object within a patient's body. The method can include introducing a portion of a metal detection device into the patient's body. As previously discussed, the metal detection device can include a handle, a shaft extending from the handle, a microcontroller including one or more processors and a memory unit, an output component, and a distal sensing portion positioned distally on the shaft.

[0047]

[0047] The distal detection unit may include a proximal gradiometer and a distal gradiometer. The proximal gradiometer may include a first proximal magnetometer and a second proximal magnetometer. The distal gradiometer may include a first distal magnetometer and a second distal magnetometer.

[0048]

[0048] The method may further include using one or more processors to calculate a differential signal from magnetic field measurements obtained from the first proximal magnetometer, the second proximal magnetometer, the first distal magnetometer, and the second distal magnetometer. The method may also include using one or more processors to apply at least one of a signal filter and a derivative to the calculated differential signal to obtain a detection signal. When taking the derivative of the differential signal, the method may further include reducing the derivative of the differential signal by a motion cancellation signal.

[0049]

[0049] The method may also include using one or more processors to compare the detection signal with a sensitivity or a detection threshold. When the detection signal exceeds the sensitivity or the detection threshold, the method may include generating a user output using an output component.

[0050]

[0050] Another method for detecting a magnetic object in a patient's body is also disclosed. This method may include introducing a portion of a metal detection device into the patient's body. As previously discussed, the metal detection device may include a handle, a shaft extending from the handle, a distal detection unit positioned distally on the shaft, a flexible portion connecting the shaft to the distal detection unit, a microcontroller including one or more processors and a memory unit, and an output component. The distal detection unit may include a plurality of magnetometers.

[0051]

[0051] Further, the method may include bending the flexible portion by pulling a trigger on the handle when at least a part of the distal detection portion and the flexible portion is inside the patient's body. The method may further include calculating a detection signal from magnetic field measurements obtained from a plurality of magnetometers using one or more processors. Also, the method may include comparing the detection signal with a threshold using one or more processors. The method may further include generating a user output using an output component when the detection signal exceeds the threshold.

[0052]

[0052] Another method of testing the functionality of a metal detection device is disclosed. The method may include providing a metal detection device. The metal detection device may include a handle, a shaft extending from the handle, a microcontroller including one or more processors and a memory unit, an output component, a distal detection portion positioned distally on the shaft, and a sensor housing covering the distal detection portion. The distal detection portion may include a plurality of magnetometers.

[0053]

[0053] Also, the method may include sliding a test bar slider on the handle distally towards the shaft. Sliding the test bar slider can translate a distal segment of a test bar housed within a lumen extending through the shaft into the sensor housing. The method may further include calculating a detection signal from magnetic field measurements obtained from a plurality of magnetometers using one or more processors when the distal segment of the test bar is translated into the sensor housing.

[0054]

[0054] Also, the method may include comparing the detection signal with a threshold using one or more processors. The method may further include generating a user output using an output component when the detection signal exceeds the threshold. Also, the method may include adjusting the threshold when the distal segment of the test bar is within the sensor housing.

Brief Description of the Drawings

[0055]

Figure 1A

[0055] Shows an isometric view of the metal detection device.

Figure 1B

[0056] Shows a side view of the metal detection device.

Figure 2A

[0057] Shows an isometric view of the handle of the metal detection device.

Figure 2B

[0058] Shows a side view of the handle of the metal detection device.

Figure 3A

[0059] Shows the flexible part of the metal detection device in a straight configuration.

Figure 3B

[0060] Shows the flexible part of the metal detection device in a bent configuration.

Figure 4A

[0061] Shows a side view of the handle of the metal detection device with the left handle casing removed.

Figure 4B

[0062] Shows a close-up side view of the handle of the metal detection device with the left handle casing removed.

Figure 5A

[0063] Shows an isometric view of the distal segment of the metal detection device with the sensor housing and the flexible part removed, and the test rod in a retracted configuration.

Figure 5B

[0064] Shows an isometric view of the distal segment of the metal detection device with the sensor housing and the flexible part removed, and the test rod in an extended configuration.

Figure 5C

[0065] Shows a plan view of the distal segment of the metal detection device with the sensor housing and the flexible part removed, and the test rod in an extended configuration.

Figure 5D

[0066] Shows a cross-sectional view of the distal segment of the metal detection device along section A-A shown in FIG. 5C.

Figure 6A

[0067] Shows a close-up of the distal detection part of the metal detection device with the sensor housing removed.

Figure 6B

[0068] A close-up perspective view of the distal sensing portion of the metal detection device is shown with the sensor housing removed.

Figure 7A

[0069] An isometric view of another variant of the distal sensing portion of the metal detection device is shown with the sensor housing removed.

Figure 7B

[0070] A close-up isometric view of the distal sensing portion of FIG. 7A is shown.

Figure 7C

[0071] Another variant of the distal sensing portion is shown with the sensor housing covering the distal sensing portion.

Figure 8A

[0072] A rear close-up isometric view of the clock ring of the metal detection device in the locked position is shown.

Figure 8B

[0073] A rear close-up isometric view of the clock ring in the unlocked position is shown.

Figure 8C

[0074] A close-up side view of the clock ring in the locked position is shown.

Figure 8D

[0075] A cross-sectional view of the clock ring in the locked position along section C-C shown in FIG. 8C is shown.

Figure 8E

[0076] A close-up side view of the clock ring in the unlocked position is shown.

Figure 8F

[0077] A cross-sectional view of the clock ring in the unlocked position along section D-D shown in FIG. 8E is shown.

Figure 8G

[0078] A front close-up isometric view of the clock ring in the locked position is shown with the nose cap removed.

Figure 8H

[0079] A front close-up isometric view of the clock ring in the unlocked position is shown with the nose cap removed.

Figure 9A

[0080] A black-and-white image of a modified example of a metal detection device used to detect a surgical suture needle in a pig's intestine.

Figure 9B

[0081] A black-and-white image of forceps used to retrieve a surgical suture needle during detection by a metal detection device.

Figure 10A

[0082] Shows a modified example of a metal detection device used to detect a sponge with an RFID tag or one or more metal markers inside a patient's body.

Figure 10B

[0083] Shows a metal detection device used to detect a wire inside a patient's body.

Figure 11A

[0084] Shows a modified example of a metal detection device used to detect a wire inside a patient's body by a closed-loop detection mechanism.

Figure 11B

[0085] Shows a metal detection device used to detect a stent or other implantable scaffold inside a patient's body.

Figure 12

[0086] Shows a modified example of a magnetic blanket or shield used to at least partially cover or shield a body cavity or part of the body when a metal detection device is performing magnetic detection inside the patient's body cavity or part of the body.

Figure 13

[0087] A signal diagram representing the distal sensing part of a metal detection device passing over a surgical suture needle.

Figure 14

[0088] A signal diagram showing that the test rod is extended and the level of the metal detection device is adjusted.

Figure 15

[0089] A signal diagram representing the distal sensing part of a metal detection device passing over a part of a metal guide wire.

Figure 16A

[0090] A signal diagram showing the effect on the detection signal when the trigger of the metal detection device is pulled.

Figure 16B

[0091] A signal diagram showing that a metal detection device automatically increases a sensitivity threshold or a detection threshold according to a situation where a trigger shown in FIG. 16A is pulled.

Figure 16C

[0092] Another signal diagram showing that a metal detection device automatically increases a sensitivity threshold or a detection threshold according to a situation where a trigger shown in FIG. 16A is pulled.

Figure 17A

[0093] A signal diagram showing a motion blocking signal or a motion blocker signal used to reduce a detection signal in an event where a distal detection unit of a metal detection device undergoes a sudden movement.

Figure 17B

[0093] A signal diagram showing a motion blocking signal or a motion blocker signal used to reduce a detection signal in an event where a distal detection unit of a metal detection device undergoes a sudden movement.

Figure 18

[0094] Showing a method for detecting a magnetic object in a patient's body.

Figure 19

[0095] Showing another method for detecting a magnetic object in a patient's body.

Figure 20

[0096] Showing a method for testing the functionality of a metal detection device.

Mode for Carrying Out the Invention

[0056]

[0001] FIGS. 1A to 1B show a metal detection device 100 including a handle 102, a shaft 131 extending from the handle 102, and a distal detection unit 136 positioned distally of the shaft 131. The distal detection unit 136 can be covered by a sensor housing 141. Also, the metal detection device 100 can also be referred to as a sharp object detector, a surgical metal detector, an RSI detector, or any combination thereof.

[0057]

[0002] The distal detection unit 136 can function as the distal tip or end of the device 100. As shown in FIGS. 1A to 1B, the flexible portion 145 can connect the shaft 131 to the distal detection unit 136 or the sensor housing 141 of the distal detection unit 136. As will be discussed in more detail in the following section, the flexible portion 145 can be configured to bend or curve such that when the flexible portion 145 is bent, the distal detection unit 136 approaches the shaft 131.

[0058]

[0097] FIG. 1A also shows that the shaft 131 can be rotatable about its longitudinal axis 104. By the bending of the flexible portion 145 and the rotation of the shaft 131, an operator of the device 100 (e.g., a surgeon or other medical professional) can perform in vivo detection of RSI or other ferromagnetic objects by advancing through the body lumen of a patient or around an organ.

[0059]

[0098] The sensor housing 141, the flexible portion 145, and the shaft 131 can be made of biocompatible materials. In some variations, the shaft 131 can be made in part of a metallic material, a polymeric material, or a combination thereof. The shaft 131 can be made in part of a ferromagnetic metal. The shaft 131 can be made in part of stainless steel.

[0060]

[0099] The sensor housing 141 can be made of a material that does not interfere with the magnetic field measurements performed by the sensors within the sensor housing 141. In some variations, the sensor housing 141 can be made of a non-ferromagnetic metallic material, a polymeric material, or a combination thereof. For example, the sensor housing 141 can be made in part of titanium. In other variations, the sensor housing 141 can be made in part of aluminum or an aluminum alloy. In yet another variation, the sensor housing 141 can be made in part of liquid crystal polymer. The sensor housing 141 can be made in part of surgical or medical polytetrafluoroethylene (PTFE), polycarbonate (PC), polyetheretherketone (PEEK), or a combination thereof.

[0061]

[0100] The flexible portion 145 can be partially made of a biocompatible elastomer material. In some variations, the flexible portion 145 can be partially made of a thermoplastic elastomer. For example, the flexible portion 145 can be partially made of a polyether block amide. More specifically, the flexible portion 145 can be partially made of PEBAX (registered trademark). In other variations, the flexible portion 145 can be made of surgical rubber.

[0062]

[0101] FIG. 1B shows that the sensor housing 141 can have a housing length dimension 140. The housing length dimension can be between about 40.0 mm and about 50.0 mm. For example, the housing length dimension 140 can be about 45.0 mm (more specifically, about 45.70 mm).

[0063]

[0102] In other variations, the housing length dimension 140 can be less than 40.0 mm or greater than 50.0 mm. As will be discussed in more detail in the following section, the sensor housing 141 can be sized to accommodate, among other electronic components, two gradiometers or at least four magnetometers, a plurality of operational amplifiers, an inertial measurement unit, and an LED.

[0064]

[0103] The flexible portion 145 can have a flexible portion length dimension 146. The flexible portion length dimension 146 can be between about 40.0 mm and about 60.0 mm. In some variations, the flexible portion length dimension 146 can be about 50.0 mm. For example, the flexible portion length dimension 146 can be about 50.8 mm.

[0065]

[0104] The shaft 131 can have a shaft length dimension 132. The shaft length dimension 132 can be the length of the exposed segment of the shaft 131. The shaft length dimension 132 can be between about 300.0 mm and about 400.0 mm. In some variations, the shaft length dimension 132 can be between about 325.0 mm and about 375.0 mm. For example, the shaft length dimension 132 can be about 350.0 mm.

[0066]

[0105] A segment of the shaft 131 can extend into the handle 102. When including the segment of the shaft 131 within the handle 102, the overall length of the shaft 131 can be between about 400.0 mm and about 500.0 mm (for example, about 450.0 mm).

[0067]

[0106] The shaft 131 can be hollow or include at least one lumen, which is suitable for allowing a cable, rod, wire, or communication line to pass through the shaft 131 to enable mechanical and / or electrical communication between the handle 102 and the distal sensing unit 136, the flexible portion 145, or a combination thereof. In other variations, the shaft 131 can include a plurality of lumens.

[0068]

[0107] The shaft 131 can be rigid throughout its length. In other variations, the shaft 131 can be flexible throughout its entire length to bend or conform to the shape of the body's internal cavity. The shaft 131 can also be rigid except for one or more flexible regions along its length.

[0069]

[0108] In some variations, the shaft 131 can be directly connected to the distal sensing unit 136 or the sensor housing 141 covering the distal sensing unit 136 without the flexible portion 145. In other variations, the device 100 can include multiple instances of the flexible portion 145, and the distal segment of the device 100 on the other side of the shaft 131 can be allowed to bend in multiple directions. In some variations, multiple instances of the flexible portion 145 can be scattered along the length of the shaft 131 to connect the rigid segments of the shaft 131 by the flexible portion 145.

[0070]

[0109] The handle 102 can include a left handle casing 101 and a right handle casing 103. The left handle casing 101 and the right handle casing 103 can be joined by fasteners (such as screws), adhesives, interference fits, or combinations thereof to form the handle 102. The handle 102 can include a handle cavity for housing certain electronic and / or mechanical components for operating the device 100. The handle 102 can be sized such that it can be gripped with one hand.

[0071]

[0110] The handle 102 including the left handle casing 101 and the right handle casing 103 can be made, in part, of a polymeric material, a metallic material, or a combination thereof. For example, the handle 102 can be made of a rigid polymeric material such as polycarbonate.

[0072]

[0111] It should be appreciated that there are no limitations on the actual size, shape, or configuration of the handle 102, the shaft 131, the flexible portion 145, the sensor housing 141, or combinations thereof. For example, the device 100 can be designed or sized to be held by hand by a surgeon or other medical professional such that the surgeon or other medical professional can grip the handle 102 with one hand. In other variations, the device 100 can be modified for use particularly by a robotic surgical system such that any part of the device 100 can be integrated with or easily gripped by a robotic arm.

[0073]

[0112] FIGS. 2A through 2B show that the handle 102 can include a trigger 105, a clock ring 107, a nose cap 109, one or more sensitivity wheels 115, a test bar slider 117, and a light transmissive window 147. The trigger 105 can be positioned on the back side of the handle 102. The trigger 105 can be protected by a trigger guard 106.

[0074]

[0113] As will be discussed in more detail in the following section, the user can control the bending of the flexible portion 145 by pulling the trigger 105. In response to the trigger 105 being pulled, the flexible portion 145 can be bent up to 90 degrees (see, for example, FIG. 3B) or more. When the flexible portion 145 is bent, the distal sensing portion 136 can be positioned closer to the distal end of the shaft 131.

[0075]

[0114] The metal detection device 100 can be configured to perform in vivo detection of ferromagnetic RSI or other ferromagnetic objects even when the flexible portion 145 is bent. For example, the metal detection device 100 can be configured to perform in vivo detection of ferromagnetic RSI or other articles even when the flexible portion 145 is bent from about 1 degree to about 90 degrees, or greater than 90 degrees. One technical problem associated with conventional surgical metal detectors is that such detectors are often rigid and not flexible, and the operator of such a detector (e.g., a surgeon or other medical professional) can only operate the detector by manually translating it axially along the longitudinal axis or rotating it. This limits the range of motion and detection capabilities of such detectors. For example, such detectors often cannot detect around organs and cannot extend into specific blood vessels. One technical advantage provided by the metal detection device 100 disclosed herein is that detection can be performed even when the elongated segment portion of the device 100 is bent or curved.

[0076]

[0115] The clock ring 107 can be configured to rotate when biased to the unlocked position. The clock ring 107 can be coupled to the shaft 131. Rotating the clock ring 107 can rotate the shaft 131. The rotation and unlocking of the clock ring 107 will be discussed in more detail in the following section.

[0077]

[0116] The nose cap 109 can function as the distal cap of the handle 102. The nose cap 109 can also function as a receiving and supporting surface for the clock ring 107 when the clock ring 107 rotates.

[0078]

[0117] One or more sensitivity wheels 115 and a test bar slider 117 are positioned above the trigger 105 to enable an operator (e.g., a surgeon or other medical professional) to hold the handle 102 and pull the trigger 105 while simultaneously operating the test bar slider 117, the sensitivity wheel 115, or a combination thereof.

[0079]

[0118] FIG. 2A shows that the device 100 can include two sensitivity wheels 115 positioned on both the left and right sides of the test bar slider 117. This enables both right-handed and left-handed operators to easily hold and operate the device 100.

[0080]

[0119] One or more sensitivity wheels 115 can be rotated (e.g., rotated forward or distally, and also rotated backward or proximally) to adjust the detection sensitivity. As will be discussed in more detail in the following section, adjusting one or more sensitivity wheels 115 can adjust the detection sensitivity of the device 100. For example, adjusting one or more sensitivity wheels 115 can increase or decrease the programmed detection threshold. Also, for example, adjusting one or more sensitivity wheels 115 can adjust the operating mode of the device 100 to process detection signals differently. Further, an operator or user of the device 100 can also switch between different operating modes (e.g., a high-speed high-sensitivity mode or a low-speed low-sensitivity mode) during detection.

[0081]

[0120] The test bar slider 117 can be slid forward (distally) or backward (proximally) to translate the test bar 133 (see, for example, FIGS. 4A to 4B and FIGS. 5B to 5D) in and out of the sensor housing 141 in parallel. The test bar slider 117 can be mounted between the left handle casing 101 and the right handle casing 103. The test bar 133 and the test bar slider 117 will be discussed in more detail in the following section.

[0082]

[0121] The light transmission window 147 can allow the light generated by the illumination component (such as an LED) in the handle 102 to be visible to the operator. The light transmission window 147 can also be referred to as a light pipe or a light bar. The light transmission window 147 can be made of a light transmission polymer material (such as an acrylic polymer), a ceramic material, or a combination thereof. The light that can be seen through the light transmission window 147 can provide useful information regarding battery life, standby indication, error warning, detection status, or a combination thereof to the operator.

[0083]

[0122] FIGS. 3A and 3B respectively show the flexible portion 145 of the device 100 in a straight configuration 142 and a bent configuration 144. As shown in FIG. 3B, when the flexible portion 145 is in the bent configuration 144, the distal sensing portion 136 can be positioned closer to the shaft 131 (i.e., the distal segment of the shaft 131).

[0084]

[0123] The flexible portion 145 can be sandwiched by the distal tube accessory 139 and the proximal tube accessory 143. The distal tube accessory 139 can be coupled to the flexible portion 145 to the distal sensing portion 136 or to the sensor housing 141 covering the distal sensing portion 136. The proximal tube accessory 143 can be coupled to the flexible portion 145 to the shaft 131. The distal tube accessory 139 and the proximal tube accessory 143 can function as the ends of the flexible portion 145.

[0085]

[0124] As will be discussed in more detail in the following section, the pull cable 135 within the shaft 131 (see, for example, FIGS. 4B and 5D) can extend along the lengths of the shaft 131 and the flexible portion 145, and the distal end of the pull cable 135 can be grounded or otherwise coupled to the distal tube accessory 139. For example, the pull cable 135 can be passed through a hole defined in the distal tube accessory 139 and knotted to secure the distal end of the pull cable 135 to the distal tube accessory 139. In other variations, a ferrule or other type of ring, cap, or clip can be used to attach the distal end of the pull cable to the distal tube accessory 139.

[0086]

[0125] The proximal end of the pull cable 135 can be coupled to the trigger 105. For example, the proximal end of the pull cable 135 can be wound around a spool within the trigger 105.

[0087]

[0003] By pulling the trigger 105, the pull cable 135 can be pulled to bend the flexible portion 145 into the bent configuration 144. The flexible portion 145 can be made flexible enough to allow bending in any desired direction.

[0088]

[0126] When the trigger 105 is released, the flexible portion 145 can be biased by one or more structures within the flexible portion 145 to return to the straight configuration 142. For example, the flexible portion 145 can be biased or pushed back to the straight configuration 142 by a spring tube 137 (see, for example, FIGS. 4A - 4B, 5A - 5B, and 5D) that extends through the flexible portion 145.

[0089]

[0127] The flexible part 145 can be bent up to 90 degrees or more in response to the pulling of the trigger 105. For example, when the trigger 105 is pulled, the flexible part 145 can be bent at about 30 degrees, about 45 degrees, about 60 degrees, or about 90 degrees with respect to the straight configuration 142. Also, when the trigger 105 is further pulled, the flexible part 145 can be bent at about 95 degrees, about 100 degrees, about 105 degrees, about 110 degrees, about 115 degrees, or about 120 degrees.

[0090]

[0128] In other variations, the trigger 105 can be replaced with another type of mechanical actuator such as one or more levers, wheels, knobs, handles, or combinations thereof. In yet another variation, the trigger 105 can be replaced with an electrical actuator such as one or more buttons, switches, or combinations thereof.

[0091]

[0129] Also, FIGS. 3A and 3B show that the sensor housing 141 can have a housing diameter 138. The housing diameter 138 can be between about 3.0 mm and about 10.0 mm. For example, the housing diameter 138 can be about 5.0 mm.

[0092]

[0130] The flexible part 145 can have a flexible part diameter. The flexible part diameter can be between about 3.0 mm and about 10.0 mm. For example, the flexible part diameter can be about 5.0 mm.

[0093]

[0131] The shaft 131 can have a shaft diameter. The shaft diameter can be between about 3.0 mm and about 10.0 mm. For example, the shaft diameter can be about 5.0 mm.

[0094]

[0132] When the housing diameter, the diameter of the flexible portion, and the shaft diameter are all approximately 5.0 mm, the elongated segment of the device 100 (including the sensor housing 141, the flexible portion 145, and the shaft 131) can be housed within a standard surgical trocar. This enables the device 100 to be used in laparoscopic surgery, open surgery, or robotic surgery.

[0095]

[0133] Figure 4A shows a side view of the handle 102 with the left handle casing 101 removed to view some of the components and mechanisms within the handle 102. Figure 4A shows that the handle 102 may include a handle printed circuit board (PCB) 123. The handle PCB 123 may extend from the handle grip 114 of the handle 102 to the handle barrel 116.

[0096]

[0134] The handle PCB 123 can be a rigid PCB. In other variations, the handle PCB 123 can be a flexible PCB.

[0097]

[0135] The handle PCB 123 can function as a main circuit board for the electronic components housed within the handle 102. As shown in Figure 4A, a microcontroller 185, a speaker 181, and several potentiometers can be coupled to the handle PCB 123.

[0098]

[0136] The microcontroller 185 can include one or more processors and a memory unit. One or more processors of the microcontroller 185 can, among other things, determine the movement of specific components of the device 100, test the functionality of the device 100, acquire and process detection signals based on magnetic field measurements made by the magnetometer, and execute instructions stored in the memory unit to detect an RSI or other ferromagnetic object based on such processed detection signals.

[0099]

[0137] In some variations, the microcontroller 185 can be a low-power reduced instruction set computer (RISC) based microcontroller. The microcontroller 185 can be an 8-bit microcontroller. In other variations, the microcontroller can be a 16-bit or 32-bit microcontroller. For example, the microcontroller 185 can be the ATmega32U4 microcontroller distributed by Microchip Technology Inc.

[0100]

[0138] The microcontroller 185 can include flash memory, static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), or a combination thereof. For example, the microcontroller 185 can include at least 32 kilobytes (KB) of flash memory, 2.5 KB of SRAM, and 1 KB of EEPROM.

[0101]

[0139] The microcontroller 185 can have a CPU speed of at least 16 MIPS at 16 MHz. In other variations, the microcontroller 185 can have a CPU speed of 28 MIPS at 33 MHz or 36 MIPS at 40 MHz.

[0102]

[0140] The microcontroller 185 can also include an analog-to-digital converter (ADC). For example, the microcontroller 185 can include a 12-channel 10-bit ADC. In other variations, the microcontroller 185 can include a 12-bit ADC or a 16-bit ADC. The ADC can convert the voltage data (from 0V to about 5V) obtained from the magnetometer into digital data. For example, the voltage data obtained from the magnetometer and other sensors can be converted in units of any signal value range (bin) (see, for example, FIGS. 13 to 17B).

[0103]

[0141] Although not shown in FIGS. 4A and 4B, in the present disclosure, it is considered that the handle 102 may also include an inertial measurement unit (IMU). The IMU can provide up to 6 degrees of freedom (DoF). The IMU can be a 6-axis IMU including a 3-axis accelerometer and a 3-axis gyroscope. The IMU can measure inclination, angular velocity, and acceleration on three perpendicular axes. In some variations, the IMU can be a low-power, low-noise 16-bit IMU. For example, the IMU can be a BMI055, MBI088, or BMI160 IMU provided by Bosch Sensortec GmbH. The IMU can be another example of the IMU 159 shown in FIG. 6 or FIGS. 7A to 7C. The IMU can be the handle PCB 123.

[0104]

[0142] The data obtained from the IMU can be used as part of the calculations regarding the movement of the handle 102. For example, using the data obtained from the IMU 159 and the potentiometer, it can be determined whether an operator (e.g., a surgeon or other medical professional) has shaken or swayed the handle 102, or has moved the handle 102 too quickly. One or more processors of the microcontroller 185 can be programmed to execute another instruction to ignore sudden movements of the handle 102 or movements exceeding one or more movement thresholds based on the acceleration data obtained from the 3-axis accelerometer and the rotation data obtained from the 3-axis gyroscope.

[0105]

[0143] Device 100 can include several output components coupled to the handle PCB 123. The output components can include one or more lights and / or audio components. The output components can be configured to generate a user output (e.g., audio and / or light) to notify the user about a detected RSI or ferromagnetic object. Also, the output components can be configured to generate a user output indicating the functionality or operating status of device 100. For example, the output components can generate a user output that conveys information about the battery life, standby indication, error alert, detection status, or combinations thereof of device 100.

[0106]

[0144] The output components can include the speaker 181, the proximal light emitting diode (LED) 173, the distal LED 183 (see FIG. 6A), or combinations thereof. The speaker 181 and / or the proximal LED 173 can be coupled to the handle PCB 123. In other variations, only the speaker 181 can be coupled to the handle PCB 123.

[0107]

[0145] As shown in FIG. 4A, the speaker 181 can be positioned within the handle grip 114. In other variations, the speaker 181 can be positioned within the handle barrel 116.

[0108]

[0146] The speaker 181 can be configured to transmit an audio or voice message to inform the operator about a detected RSI or other ferromagnetic object, or to convey information regarding the functionality or operating status of device 100. For example, the speaker 181 can generate an audio or voice message that conveys information about the battery life, standby indication, error alert, detection status, or combinations thereof of device 100.

[0109]

[0147] The sound can be a beep sound, a ringing sound, a chime, a pitched tonal sound, or a combination thereof. The audio message can be a recorded message or phrase.

[0110]

[0148] The proximal LED 173 can be positioned within the handle barrel 116. In other variations, the proximal LED 173 can be positioned proximate to the nose cap 109 or along the handle grip 114.

[0111]

[0149] The handle 102 can further include a light transmissive window 147. The light transmissive window 147 can be positioned directly above or near the proximal LED 173. The light transmissive window 147 can allow the light generated by the proximal LED 173 to be visible to the operator. The light transmissive window 147 can also be referred to as a light pipe or a light bar. The light transmissive window 147 can be made of a light transmitting polymer material (e.g., acrylic polymer), a ceramic material, or a combination thereof.

[0112]

[0150] Additionally, the device 100 can also include a distal LED 183. The distal LED 183 can be coupled to a flexible circuit or a circuit board within the distal sensing unit 136 (see FIG. 6A). The sensor housing 141 can include a light transmissive window or a light transmission section to allow the light generated by the distal LED 183 to be visible to the operator via endoscopy.

[0113]

[0151] The distal LED 183 can function in the same manner as the proximal LED 173. Also, the distal LED 183 can generate the same light or light pattern as that generated by the proximal LED 173 (and vice versa). The light or light pattern generated by the proximal LED 173 and / or the distal LED 183 can convey information regarding the battery life, standby indication, error alert, detection status, or a combination thereof of the device 100.

[0114]

[0152] For example, both the proximal LED 173 and the distal LED 183 can generate a green blinking light pattern (pulse light pattern) to indicate that the device 100 is operating. The proximal LED 173 can generate a red blinking light pattern to inform the operator that one or more electronic components or sensors within the sensor housing 141 have become disconnected, or that the entire sensor housing 141 has become detached or its connection has been severed. Also, the speaker 181 can generate an alarm sound when one or more electronic components or sensors within the sensor housing 141 become disconnected, or when the entire sensor housing 141 becomes detached or its connection is severed.

[0115]

[0153] Also, the speaker 181 can generate a beep sound or a beep sound pattern when the detection signal exceeds the sensitivity or detection threshold, to inform the operator that the device 100 may have detected an RSI or other ferromagnetic object. The sound (e.g., beep sound or sound pattern) generated by the speaker 181 can correspond to the magnitude by which the detection signal exceeds the sensitivity or detection threshold. For example, when the magnitude by which the detection signal exceeds the sensitivity or detection threshold exceeds a predetermined magnitude threshold, the speaker 181 can generate a louder beep sound or sound pattern. Also, when the detection signal exceeds the sensitivity or detection threshold, the proximal LED 173, the distal LED 183, or a combination thereof can generate light or a light pattern (e.g., continuous blue light or blinking blue light). In some variations, the brightness of the light or light pattern generated by the proximal LED 173, the distal LED 183, or a combination thereof can correspond to the magnitude by which the detection signal exceeds the sensitivity or detection threshold. For example, when the magnitude by which the detection signal exceeds the sensitivity or detection threshold exceeds a predetermined magnitude threshold, the proximal LED 173, the distal LED 183, or a combination thereof can generate brighter light or a light pattern.

[0116]

[0154] FIG. 4A also shows that device 100 may include a power source configured to supply power to device 100 and its various electronic components. In some variations, the power source can be a portable power source such as one or more batteries 149. As shown in FIG. 4A, one or more batteries 149 can be housed within handle 102. For example, handle grip 114 can include a battery holder or battery retaining compartment that includes a positive battery terminal 125 and a negative battery terminal 127.

[0117]

[0155] In some variations, battery 149 can be a rechargeable battery. In these variations, device 100 may include an input for receiving power to charge battery 149 from an external power source. In yet another variation, device 100 includes an input for receiving power from an external power source and can be powered entirely by the external power source without battery 149.

[0118]

[0156] As shown in FIGS. 4A and 4B, handle 102 can further include a trigger 105, a trigger potentiometer 171 coupled to at least a portion of trigger 105, and a trigger spring 121. The proximal segment of pull cable 135 can be coupled to at least a portion of trigger 105.

[0119]

[0157] Trigger 105 can be actuated to control the bending of flexible portion 145. As described above, trigger 105 can be coupled to flexible portion 145 by a pull cable 135 that extends through shaft 131 and flexible portion 145. When trigger 105 is pulled, pull cable 135 is pulled and flexible portion 145 bends. When flexible portion 145 bends, distal sensing portion 136 approaches shaft 131.

[0120]

[0158] As shown in FIG. 4B, the trigger 105 may include a pull cable hole 165. The pull cable 135 extends through the pull cable hole 165 and can be tied or otherwise fixed to the trigger 105 at the pull cable hole 165. In other variations, the proximal segment or proximal end of the pull cable 135 can extend into a cavity within the trigger 105 and can be wound around a spool within the trigger 105. The pull cable 135 can also be attached to the trigger 105 by an adhesive, clip, string, ferrule, or combination thereof.

[0121]

[0159] As described above, the pull cable 135 can extend along the lengths of the shaft 131 and the flexible portion 145, and the distal end of the pull cable 135 can be tied or otherwise coupled to the distal tube accessory 139 at the distal end of the device 100.

[0122]

[0160] For example, the pull cable 135 can be passed through a hole defined in the distal tube accessory 139 and knotted to secure the distal end of the pull cable 135 to the distal tube accessory 139. In other variations, a ferrule or other type of ring, cap, or clip can be used to attach the distal end of the pull cable to the distal tube accessory 139.

[0123]

[0161] In some variations, the pull cable 135 can be a braided cable or wire, such as a braided stainless steel cable. In other variations, the pull cable 135 can be a polymer cable or wire, such as a nylon cable or wire.

[0124]

[0162] The trigger spring 121 can apply a spring load to the trigger 105 to return it to the starting position after the trigger 105 is pulled. The trigger spring 121 can be a torsion spring. The trigger spring 121 can engage features inside the handle 102 to provide resistance.

[0125]

[0163] When the trigger 105 is pulled, the pull cable 135 is pulled, and the flexible portion 145 can be bent into the bent configuration 144. The flexible portion 145 can be made flexible enough to allow bending in any desired direction.

[0126]

[0164] When the trigger 105 is released, the flexible portion 145 can be biased by one or more structures within the flexible portion 145 to return to the straight configuration 142. For example, the flexible portion 145 can be biased or pushed back to the straight configuration 142 by a spring tube 137 extending through the flexible portion 145 (see, for example, FIGS. 4A to 4B, FIGS. 5A to 5B, and FIG. 5D).

[0127]

[0165] In other variations, the trigger 105 can be replaced with another type of mechanical actuator, such as one or more levers, wheels, knobs, handles, or combinations thereof. In yet another variation, the trigger 105 can be replaced with an electrical actuator, such as one or more buttons, switches, or combinations thereof.

[0128]

[0166] FIG. 4B shows a close-up side view of the handle 102 with the left handle casing 101, the trigger spring 121, and the sensitivity wheel 115 removed for clarity. FIG. 4B shows that a trigger potentiometer 171 can be coupled to the rotatable portion of the trigger 105. For example, the trigger potentiometer 171 can be coupled to a trigger shaft (not visible in FIG. 4B) extending through the trigger potentiometer 171.

[0129]

[0167] The trigger potentiometer 171 can be a rotary potentiometer. In some variations, the trigger potentiometer 171 can be mounted on a part of the handle PCB 123. In other variations, the trigger potentiometer 171 can be mounted on another PCB within the handle 102.

[0130]

[0168] The trigger potentiometer 171 can provide data regarding trigger speed (e.g., how fast the trigger is pulled). When the flexible portion 145 is bent, the distal sensing portion 136 undergoes a sudden movement and approaches the ferromagnetic shaft 131, so that the sensitivity threshold or detection threshold can be adjusted using the data provided by the trigger potentiometer 171.

[0131]

[0169] For example, one or more processors of the microcontroller 185 can be programmed to increase the sensitivity or detection threshold (i.e., decrease the detection sensitivity) to address the magnetic field distortion caused by the shaft 131 and / or the sudden movement of the distal sensing portion 136 when the distal sensing portion 136 is bent towards the shaft 131. For example, using the data obtained from the trigger potentiometer 171, it can be determined that the operator has suddenly moved or pulled the distal sensing portion 136 by pulling the trigger 105 too hard or too fast.

[0132]

[0170] Increasing the sensitivity or detection threshold (which can also be said to decrease or reduce the detection or sensitivity level) can be performed to avoid false positive signals. When the trigger is pulled or moved too quickly, there is a possibility of generating sharp spikes in the detected magnetic field. In such cases, one or more processors of the microcontroller 185 can be programmed to execute instructions for determining whether the trigger movement exceeds a trigger movement threshold or a trigger movement threshold range, and one or more processors can also be programmed to execute another instruction for increasing the programmed sensitivity or detection threshold (i.e., decreasing the sensitivity level of the device 100) in response to the sudden or uncontrolled movement of the trigger 105. This can be performed to prevent or tamper with false positive signals. Thus, the data obtained from the trigger potentiometer 171 can be incorporated into the detection algorithm executed by the microcontroller 185.

[0133]

[0171] The handle 102 can further include one or more sensitivity wheels 115, which are configured to adjust a programmed sensitivity or detection threshold in response to rotation of the one or more sensitivity wheels 115. At least a portion of the one or more sensitivity wheels 115 protrudes from one or more notches defined along the handle casing, enabling an operator to turn or rotate a dial of the one or more sensitivity wheels 115.

[0134]

[0172] The operator can turn or rotate a dial of the sensitivity wheel 115 to increase or decrease the programmed sensitivity or detection threshold. For example, the operator can turn or rotate a dial of at least one of the sensitivity wheels 115 forward (i.e., in the distal direction) to increase the sensitivity level of the device 100. Increasing the sensitivity level of the device 100 enables the device 100 to more accurately detect the presence of small or weakly magnetized RSI or other ferromagnetic objects within the subject's body. Increasing the sensitivity level of the device 100 can decrease the programmed sensitivity or detection threshold.

[0135]

[0173] The operator can turn or rotate a dial of at least one of the sensitivity wheels 115 backward (i.e., in the proximal direction) to decrease the sensitivity level of the device 100. Decreasing the sensitivity level of the device 100 can increase the programmed sensitivity or detection threshold. The operator can decrease the sensitivity level of the device 100 when it is difficult for the operator to sense an actual detection signal due to a false positive signal from a ferromagnetic medical device (e.g., a metal surgical instrument or cart) in proximity to the patient.

[0136]

[0174] Device 100 can include several distinct sensitivity levels. For example, device 100 can include 11 distinct sensitivity levels, and the default level can be level 7. When the sensitivity level reaches either the upper limit (e.g., level 11) or the lower limit (e.g., level 1), device 100 can generate a user output (e.g., two beeps or continuous beeps).

[0137]

[0175] One or more sensitivity wheels 115 can be rotatably coupled to a sensitivity rotary potentiometer 169 (see FIG. 4B. For clarity, the sensitivity wheel 115 is removed in FIG. 4B). The sensitivity rotary potentiometer 169 can be coupled to the handle PCB 123.

[0138]

[0176] The sensitivity rotary potentiometer 169 provides data regarding the rotation of the wheel, and thereby can provide data regarding the sensitivity level desired by the operator.

[0139]

[0177] One or more processors of the microcontroller 185 can be programmed to smooth the potentiometer signal obtained from the sensitivity rotary potentiometer 169 to reduce signal noise and to observe such signals for continuous upward or downward signal spikes that occur when the operator turns at least one dial of the sensitivity wheel 115 forward or backward. One or more processors of the microcontroller 185 can be programmed to execute instructions for adjusting the sensitivity or detection threshold when either two consecutive upward sensitivity signal spikes or two consecutive downward signal spikes are detected. For example, one or more processors of the microcontroller 185 can be programmed to execute instructions for lowering the sensitivity or detection threshold (i.e., increasing the sensitivity level) when two consecutive upward signal spikes from the sensitivity rotary potentiometer 169 are observed.

[0140]

[0178] Also, the sensitivity level of device 100 can be automatically adjusted by device 100 (i.e., without operator input). For example, when the movement of the trigger calculated from the data obtained from the trigger potentiometer 171 exceeds the trigger movement threshold, the sensitivity level of device 100 can be decreased and the sensitivity or detection threshold can be increased. Also, for example, when the magnetometer is periodically reset to remove a settling event or level change, the sensitivity level of device 100 can be decreased and the sensitivity or detection threshold can be increased. For example, the magnetometer can be periodically reset (e.g., every 5 seconds) using a mag reset function to readjust the domains within the magnetometer by means of a current pulse. This is performed when the magnetometer is significantly affected by a strong magnetic field. When the magnetometer is reset, transient signal spikes or bumps may occur. Increasing the sensitivity or detection threshold simultaneously with resetting the magnetometer can reduce the possibility of false positive signals.

[0141]

[0179] In this example, one or more sensitivity wheels 115 are mentioned, but it should be contemplated by the present disclosure and understood by those skilled in the art that one or more sensitivity wheels 115 are merely an example of a sensitivity actuator. In other variations, the sensitivity actuator may be implemented as one or more sliders, knobs, buttons, switches, or combinations thereof. In yet another variation, the sensitivity actuator may be implemented as a user interface control device presented by an electronic display or touchpad.

[0142]

[0180] Also, FIGS. 4A and 4B show that the handle 102 can include a test bar slider 117. In some variations, the test bar slider 117 can slide along the back of the handle barrel 116. The test bar slider 117 can slide forward (distally) or backward (proximally) or otherwise translate axially to translate the test bar 133 within the shaft 131. Sliding the test bar slider 117 forward can extend the distal end of the test bar 133 into the sensor housing 141 and bring it close to or drive it to be close to the magnetometer of the distal sensing portion 136.

[0143]

[0181] The test bar 133 can be made of a ferromagnetic material in part. For example, the test bar 133 can be made of a ferromagnetic metal in part. The test bar 133 can be made of a magnetic stainless steel such as ferritic stainless steel, martensitic stainless steel, or duplex stainless steel in part.

[0144]

[0182] The test bar 133 can be flexible and bendable. For example, the test bar 133 can be implemented as a flexible ferromagnetic cable or rod.

[0145]

[0183] The test bar 133 has known magnetic characteristics, and when the test bar 133 is extended into the sensor housing 141, the distortion of the magnetic field generated by the test bar 133 can be accounted for. The test bar 133 can be used to verify the functionality of the device 100 and / or perform in-situ re-zero of the magnetic field environment.

[0146]

[0184] The test rod slider 117 can have a spring load applied thereto by a tension spring 119 such that when no distal - direction force is applied to the test rod slider 117, the test rod slider 117 is pulled back to its default starting position (see, for example, FIG. 4B). One end of the tension spring 119 is grounded to the right handle 102, and the other end of the tension spring 119 can be attached to or coupled with at least a portion of the test rod slider 117.

[0147]

[0185] The proximal end of the test rod 133 can be fixed to or otherwise coupled with the test rod slider 117. For example, the proximal end of the test rod 133 can be fixed to the proximal portion of the test rod slider 117 by an adhesive, a fastener, a cord, a clip, or a combination thereof.

[0148]

[0186] The test rod 133 can be partially housed within the spring tube 137. The distal end of the test rod 133 can extend out of the spring tube 137. The proximal end of the spring tube 137 can be fixed to or otherwise coupled with the right - handle casing 103. For example, the proximal end of the spring tube 137 can be fixed to a feature of the right - handle casing 103 by an adhesive, a fastener, a cord, a clip, or a combination thereof. The spring tube 137 can extend from the handle 102 through the shaft 131 and the flexible portion 145.

[0149]

[0187] In addition to functioning as a housing for the test rod 133, the spring tube 137 can also be used to bias the flexible portion 145 back to its non - bent configuration 144 when the trigger 105 is released. The spring tube 137 can be partially made of polyethylene terephthalate (PET). In other variations, the spring tube 137 can be made of a polymeric material or copolymer that exhibits shape - memory characteristics. Also, the spring tube 137 can provide a certain degree of rigidity or structure to the flexible portion 145.

[0150]

[0188] One advantage of using the spring tube 137 to accommodate the test bar 133 and to bias the flexible portion 145 back to the non-bent configuration 144 is that the same components can provide multiple functions, reducing the total number of components extending through the small-diameter shaft. This also helps to reduce the overall complexity of the device 100.

[0151]

[0189] The handle 102 further includes a slider potentiometer 167 mounted on or otherwise coupled to the handle PCB 123. The slider potentiometer 167 can be coupled to at least a portion of the test bar slider 117 via a gear.

[0152]

[0190] For example, FIGS. 4A and 4B show that the test bar slider 117 can be coupled to a rack gear 128 configured to interact with a spur gear 129. The spur gear 129 can be rotatably coupled to the slider potentiometer 167. For example, a gear shaft extending from the spur gear 129 can be coupled to the slider potentiometer 167.

[0153]

[0191] Using the data obtained from the slider potentiometer 167, the slider position of the test bar slider 117 can be determined. The slider position can indicate the relative positioning of the test bar 133 with respect to the magnetometer of the distal sensing unit 136. For example, the slider position can indicate the relative positioning of the test bar 133 with respect to at least one of the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210.

[0154]

[0192] When the test bar 133 is driven into the sensor housing 141 by the test bar slider 117 and approaches the magnetometer, one or more processors of the microcontroller 185 can be programmed to execute instructions for performing specific detection diagnostics. For example, one or more processors of the microcontroller 185 can be programmed to execute instructions for comparing the magnetic field measurement values obtained from the magnetometer with known magnetic field values associated with the ferromagnetic test bar 133.

[0155]

[0193] One or more processors of the microcontroller 185 can be programmed to execute another instruction for instructing an output component (such as the speaker 181 or the LED) to generate a user output (such as a voice or a light pattern) for notifying the operator of the diagnosis result.

[0156]

[0194] The test bar 133 can be used in combination with the sensitivity wheel 115 to accurately measure the functionality or operability of the device 100. For example, when the operator does not know whether the device 100 is functioning properly, the operator can increase the sensitivity level of the device 100 by turning the dial of the sensitivity wheel 115 forward, that is, in the distal direction. Further, by pushing the test bar slider 117 forward, the ferromagnetic test bar 133 can be translated parallelly into the sensor housing 141 to approach the magnetometer. The operator can grasp the functionality of the device 100 based on the user output generated by the device 100 in this situation.

[0157]

[0195] Also, the data obtained from the slider potentiometer 167 can be used as part of calculations or determinations (such as speed and / or acceleration) regarding the movement of the test bar 133. For example, using the data obtained from the slider potentiometer 167, it can be determined whether the operator has extended or retracted the test bar 133 too quickly.

[0158]

[0196] Also, when the data obtained from the slider potentiometer 167 indicates that the test bar slider 117 is pushed forward to test the functionality of the device 100, the device 100 can automatically increase the sensitivity level. The device 100 can automatically increase the sensitivity level (thereby reducing the sensitivity or detection threshold) to increase the likelihood that the test bar 133 will be detected by the magnetometer. For example, one or more processors of the microcontroller 185 can be programmed to execute instructions for determining that the test bar 133 is being advanced forward based on the data or signal obtained from the slider potentiometer 167. One or more processors of the microcontroller 185 can be programmed to execute another instruction for reducing the sensitivity or detection threshold in response to the test bar 133 being advanced forward or into the sensor housing 141.

[0159]

[0197] In other examples, test bar 133 can be used to cancel false positive signals or noise caused by ferromagnetic objects within the detection environment. For example, test bar 133 can be used to cancel false positive signals or noise caused by ferromagnetic medical devices (such as metal surgical instruments or carts) in proximity to the patient. Such noise can make it difficult for the operator to sense the actual detection signal. For example, an operator desiring to perform a magnetic environment re-zeroing can apply a distal force to test bar slider 117 to extend test bar 133 into sensor housing 141 and maintain test bar 133 in this extended configuration for a time period exceeding a predetermined time threshold. In response to test bar 133 being maintained in this extended configuration, one or more processors of microcontroller 185 can be programmed to execute instructions to increase the sensitivity or detection threshold and decrease the sensitivity level of device 100 until most (or a significant number of) false positive signals excluding the signal caused by test bar 133 are smaller than the new sensitivity or detection threshold. Thereafter, even when the operator releases the hand from test bar slider 117 and test bar 133 retracts into sensor housing 141 to the retracted configuration, this new higher sensitivity or detection threshold can be maintained. The operator can then perform detection at this new decreased sensitivity level (i.e., high sensitivity or detection threshold).

[0160]

[0198] FIG. 5A shows an isometric view of the distal segment of device 100 with sensor housing 141 and flexible portion 145 removed for clarity and test bar 133 shown in the retracted configuration 130. The retracted configuration 130 can be the default configuration of test bar 133. In the retracted configuration 130, the distal end of test bar 133 can be within spring tube 137. In the retracted configuration 130, test bar 133 can be positioned at a sufficient distance from the magnetometer so that the magnetism of test bar 133 does not significantly affect the detection of RSI or other ferromagnetic metal objects.

[0161]

[0199] Figure 5B is an isometric view of the distal segment of the same device 100 shown in Figure 5A, but the test bar 133 is shown in the extended configuration 134. When the operator advances the test bar slider 117 on the handle 102 and applies a distal force to the test bar slider 117 to maintain it in its advanced position (for example, by leaving the operator's finger on the test bar slider 117), the test bar 133 can assume the extended configuration 134. When the test bar 133 is in the extended configuration 134, the distal end of the test bar 133 can extend or advance from the spring tube 137 into the sensor housing 141 (not shown in Figure 5B for clarity). When in the extended configuration 134, the test bar 133 is in sufficient proximity to the magnetometers of the distal sensing portion 136 such that at least one of the magnetometers can detect the ferromagnetic test bar 133 (the distortion of the magnetic field generated by the test bar 133 can be detected by at least one of the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210).

[0162]

[0200] When the test bar 133 is in the extended configuration 134, the distal end of the test bar 133 can be separated from the second proximal magnetometer 204 by several millimeters. For example, when the test bar 133 is in the extended configuration 134, the distal end of the test bar 133 can be separated from the second proximal magnetometer by from about 1.0 mm to about 5.0 mm. In other variations, when the test bar 133 is in the extended configuration 134, the distal end of the test bar 133 can be separated from the second proximal magnetometer 204 by from about 5.0 mm to about 10.0 mm. In other variations, when the test bar 133 is in the extended configuration 134, the distal end of the test bar 133 can be separated from the second proximal magnetometer by more than 10.0 mm or less than 1.0 mm. In yet another variation, when the test bar 133 is in the extended configuration 134, the distal end of the test bar 133 can be positioned above but not in contact with one or more of the magnetometers.

[0163]

[0201] For example, in some variations, when the test bar 133 is in the extended configuration 134, the distal end of the test bar 133 can be positioned approximately 1.0 mm past the second proximal magnetometer 204.

[0164]

[0202] In an alternative variation, when the test bar 133 is in the extended configuration 134, the distal end of the test bar 133 can be positioned approximately 1.0 mm past the first proximal magnetometer 202.

[0165]

[0203] In a further variation, when the test bar 133 is in the extended configuration 134, the distal end of the test bar 133 can be positioned approximately 1.0 mm past the first distal magnetometer 208 or the second distal magnetometer 210. In these variations, the entire test bar 133 can be positioned over the magnetometer.

[0166]

[0204] FIG. 5C shows a plan view of the distal segment of the device 100 with the sensor housing 141 and the flexible portion 145 removed for clarity, and the test bar 133 is shown in the extended configuration 134. FIG. 5D shows a cross-sectional view of the same distal segment along the section A-A shown in FIG. 5C.

[0167]

[0205] FIGS. 5C and 5D show that the elongated flex circuit 157 can couple one or more PCBs within the distal sensing portion 136 to the handle PCB 123. For example, the elongated flex circuit 157 can couple the proximal rigid PCB 161 to the handle PCB 123. By the elongated flex circuit 157, the magnetometers, amplifiers, and other electronic components within the distal sensing portion 136 can communicate electrically with the microcontroller 185 mounted on the handle PCB 123. When the flexible portion 145 is pulled into the bent configuration 144 in response to pulling the trigger 105, the segment of the elongated flex circuit 157 extending through the flexible portion 145 can bend or curve.

[0168]

[0206] The elongated flex circuit 157 or flexible printed circuit can include a conductive metal foil joined to a flexible polymer film such as a PET film or polyimide film by printing, adhesion, lamination, deposition, and / or other methods. In other variations, the elongated flex circuit 157 can be a rigid-flex PCB or a flexible printed circuit having a certain degree of rigidity.

[0169]

[0207] The elongated flex circuit 157 can be positioned between the pull cable 135 and the shaft 131 within the spring tube 137 and the flexible portion 145 that partially houses the test rod 133. The pull cable 135 can be positioned near the lower or ventral side of the flexible portion 145 and the shaft 131.

[0170]

[0208] As previously discussed, the distal end of the pull cable 135 can be grounded or otherwise coupled to the distal tube accessory 139. As shown in FIG. 5D, the distal end of the pull cable 135 can be grounded or otherwise coupled to the distal tube accessory 139 below or beneath the elongated flex circuit 157.

[0171]

[0209] For example, the pull cable 135 can be passed through a hole defined in the distal tube accessory 139 and knotted to secure the distal end of the pull cable 135 to the distal tube accessory 139. In some variations, the hole in the distal tube accessory 139 can be positioned below or beneath the elongated flex circuit 157. In other variations, a ferrule or other type of ring, cap, or clip can be used to attach the distal end of the pull cable to the distal tube accessory 139.

[0172]

[0210] The spring tube 137 can be positioned near the upper or dorsal side of the flexible portion 145 and the shaft 131. As shown in FIG. 5D, the distal end of the spring tube 137 can be coupled to the distal tube accessory 139 above or over the elongated flex circuit 157.

[0173]

[0211] One technical advantage of arranging the tube, circuit, and cable within the flexible portion 145 is that the flexible portion 145 can be bent quickly and effectively, and can similarly be restored to a configuration that is not bent as easily, i.e., a straight configuration. For example, the spring tube 137 within the flexible portion 145 enables the flexible portion 145 to bounce back to its default straight configuration. Further, the flexible portion 145 can be bent without adversely affecting the test rod 133 within the spring tube 137.

[0174]

[0212] The metal detection device 100 can be configured to perform a test (e.g., a functionality test) or re-zeroing even when the flexible portion 145 is bent. For example, the metal detection device 100 can be configured to perform a test or re-zeroing even when the flexible portion 145 is bent from about 1 degree to about 90 degrees or greater than 90 degrees. To date, as far as the applicant knows, there is no surgical metal detector designed using a bendable test rod 133 that enables testing or re-zeroing when a portion of the elongated detection segment of the device 100 is bent or curved.

[0175]

[0001] Also, FIGS. 5A through 5D show that the distal sensing portion 136 can include a proximal gradiometer 200 including a first proximal magnetometer 202 and a second proximal magnetometer 204, and a distal gradiometer 206 including a first distal magnetometer 208 and a second distal magnetometer 210. For purposes of the present disclosure, the term magnetometer refers to a device or sensor for measuring a component of a magnetic field, and the term gradiometer refers to a combination of such devices or sensors for measuring the gradient of a magnetic field component.

[0176]

[0213] The first proximal magnetometer 202 and the second proximal magnetometer 204 can be mounted on a proximal PCB or circuit or coupled in other ways, and the first distal magnetometer 208 and the second distal magnetometer 210 can be mounted on a distal PCB or circuit or coupled in other ways. In the variations shown in FIGS. 5A to 5D and FIGS. 6A to 6B, the first proximal magnetometer 202 and the second proximal magnetometer 204 can be mounted on the proximal rigid PCB 161 or coupled in other ways. In this variation, the first distal magnetometer 208 and the second distal magnetometer 210 can be mounted on the distal rigid PCB 163 or coupled in other ways.

[0177]

[0214] The proximal rigid PCB 161 can be connected to the distal rigid PCB 163 by the distal flexible circuit 155 or coupled in other ways. In other variations, the first distal magnetometer 208 and the second distal magnetometer 210 can be mounted on a flexible circuit or coupled in other ways.

[0178]

[0215] FIGS. 5A to 5D show a variation of the device 100 with two gradiometers and four magnetometers, but in the present disclosure, it is also conceivable that the device 100 may include three or more gradiometers or only one gradiometer.

[0179]

[0216] The first proximal magnetometer 202 can be positioned distal to the second proximal magnetometer 204. The first distal magnetometer 208 can be positioned distal to the second distal magnetometer 210.

[0180]

[0217] The first proximal magnetometer 202 can be positioned in series distal to the second proximal magnetometer 204 such that it is positioned distal to the second proximal magnetometer 204 along the longitudinal axis (e.g., the longitudinal axis 104 shown in FIG. 1A). The first distal magnetometer 208 can be positioned in series distal to the second distal magnetometer 210 such that it is positioned distal to the second distal magnetometer 210.

[0181]

[0218] FIG. 5D shows that the first proximal magnetometer 202 can be separated from the second proximal magnetometer 204 by a proximal magnetometer separation distance 205. In some variations, the proximal magnetometer separation distance 205 can be between about 4.00 mm and 5.00 mm. For example, the proximal magnetometer separation distance 205 can be between about 4.50 mm and 4.75 mm.

[0182]

[0219] The first distal magnetometer 208 can be separated from the second distal magnetometer 210 by a distal magnetometer separation distance 207. In some variations, the distal magnetometer separation distance 207 can be between about 4.00 mm and 5.00 mm. For example, the distal magnetometer separation distance 207 can be between about 4.50 mm and 4.75 mm.

[0183]

[0220] The second distal magnetometer 210 can be separated from the first proximal magnetometer 202 by a gradiometer separation distance 209. In some variations, the gradiometer separation distance 209 can be between about 18.00 mm and 20.00 mm. For example, the gradiometer separation distance 209 can be between about 18.50 mm and 18.85 mm.

[0184]

[0221] One technical problem faced by the applicant is how to design a surgical magnetic detector that can detect small or miniature magnetic articles such as small surgical suturing needles or parts of surgical instruments that have become detached during surgery. One technical solution discovered by the applicant is that the device 100 disclosed herein has magnetometers and gradiometers positioned and separated according to the dimensions presented thus far. The applicant has discovered that with the separation distances disclosed herein (e.g., magnetometer separation distance and / or gradiometer separation distance), the device 100 can more effectively detect small surgical needles or other small ferromagnetic sharp objects or articles.

[0185]

[0222] Further, the device 100 disclosed herein has a magnetometer and a gradiometer positioned and separated according to the dimensions presented heretofore, and all of the orientation of the magnetometer and the combination of unique signals can help detect the object of interest and can also help reduce the signal size of spurious signals generated by moving through the unique magnetic field lines in the operating room (e.g., magnetic field lines due to the earth, the hospital building, medical equipment, etc.).

[0186]

[0223] Further, the distal sensing unit 136 can also include an inertial measurement unit (IMU) 159. The IMU 159 can provide up to six degrees of freedom (DoF). The IMU 159 can be a six-axis IMU including a three-axis accelerometer and a three-axis gyroscope. The IMU 159 can measure tilt, angular velocity, and acceleration along three perpendicular axes. In some variations, the IMU can be a low-power, low-noise 16-bit IMU. For example, the IMU 159 can be a BMI055, MBI088, or BMI160 IMU provided by Bosch Sensortec GmbH.

[0187]

[0224] The data obtained from the IMU 159 can be used as part of calculations regarding the speed and acceleration of the distal sensing unit 136. For example, using the data obtained from the IMU 159 and the potentiometer, it can be determined whether the operator has shaken or swayed the distal sensing unit 136. One or more processors of the microcontroller 185 can be programmed to execute yet another instruction to ignore sudden movements of at least one of the distal sensing unit 136 and the shaft 131 based on the acceleration data obtained from the three-axis accelerometer and the rotation data obtained from the three-axis gyroscope.

[0188]

[0225] In some variations, the IMU 159 can be mounted on the proximal rigid PCB 161. In other variations, the IMU 159 can be mounted on the distal rigid PCB 163 or other parts of the distal sensing unit 136.

[0189]

[0226] In some variations, the data received from the IMU 159 (e.g., acceleration data from a 3-axis accelerometer and / or gyroscope data from a 3-axis gyroscope) can affect whether the device 100 reduces the sensitivity level or detection sensitivity. Reducing the sensitivity level or detection sensitivity can include increasing the sensitivity or detection threshold to avoid false positive signals. For example, if the data received from the IMU 159 indicates that the distal sensing unit 136 is experiencing strong or exaggerated movement (e.g., the operator rotates the shaft 131 too quickly or pulls / releases the trigger too quickly), there may be a possibility of generating sharp spikes in the detected magnetic field. In such cases, one or more processors of the microcontroller 185 can be programmed to execute instructions to determine that the distal sensing unit 136 is experiencing strong or exaggerated movement based on the data obtained from the IMU 159 (e.g., when the movement data obtained from the IMU 159 exceeds a predetermined movement threshold or movement threshold range). The one or more processors can then be programmed to execute another instruction to increase the programmed sensitivity or detection threshold to reduce the sensitivity of the device 100 in response to sudden or uncontrolled movement of the distal sensing unit 136. This can be done to prevent or modify false positive signals.

[0190]

[0227] In some variations, one or more processors can be programmed to execute another instruction to divide the signals or data obtained from various magnetometers by the magnitude of the strong movement signal or a scaled version of the strong movement signal to reduce the likelihood of false positive signals caused by strong movement. This can be considered an example of movement rejection or detection signal reduction.

[0191]

[0228] FIG. 6A shows a side close-up view of one modification of the distal sensing unit 136 with the sensor housing 141 removed. The distal sensing unit 136 may include a proximal gradiometer 200 including a first proximal magnetometer 202 and a second proximal magnetometer 204, and a distal gradiometer 206 including a first distal magnetometer 208 and a second distal magnetometer 210.

[0192]

[0229] FIGS. 5A through 5D and FIGS. 6A through 6B show that the device 100 includes two gradiometers and four magnetometers. However, in the present disclosure, it is also conceivable that the device 100 may include three or more gradiometers or six or more magnetometers. In other modifications, the device 100 may include only one gradiometer including two magnetometers, or may include one gradiometer including two magnetometers and additional magnetometers disposed distally or proximally to this one gradiometer.

[0193]

[0230] The first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210 can each be a two-axis magnetometer having an x-axis and a y-axis. For example, each of the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210 can have a positive x-axis (+x-axis), a negative x-axis (-x-axis), a positive y-axis (+y-axis), and a negative y-axis (-y-axis). Each of the x-axis and the y-axis can be regarded as a sensitivity axis of the magnetometer.

[0194]

[0231] The +x-axis of the first proximal magnetometer 202 can be oriented in the opposite direction to the +x-axis of the second proximal magnetometer 204. The +y-axis of the first proximal magnetometer 202 can be oriented in the opposite direction to the +y-axis of the second proximal magnetometer 204 (see FIGS. 5C and 6A).

[0195]

[0232] The -x-axis of the first proximal magnetometer 202 can be oriented in the opposite direction to the -x-axis of the second proximal magnetometer 204. The -y-axis of the first proximal magnetometer 202 can be oriented in the opposite direction to the -y-axis of the second proximal magnetometer 204.

[0196]

[0233] By orienting the sensitivity axes (e.g., the x-axis and the y-axis) of the first proximal magnetometer 202 and the second proximal magnetometer 204 in opposite directions, the influence of a common magnetic field (e.g., the Earth's magnetic field, the magnetic field influence caused by medical devices in the operating room, or the field influence caused by movement) can be canceled or reduced so that the distortion or influence of the local magnetic field becomes more prominent, i.e., detectable, and also so that it occupies a larger portion of the entire signal.

[0197]

[0234] In another modification, only the +x-axis of the first proximal magnetometer 202 is oriented in the opposite direction of the +x-axis of the second proximal magnetometer 204, or only the +y-axis of the first proximal magnetometer 202 is oriented in the opposite direction of the +y-axis of the second proximal magnetometer 204.

[0198]

[0235] The +x-axis of the first distal magnetometer 208 can be oriented in the opposite direction of the +x-axis of the second distal magnetometer 210, and the +y-axis of the first distal magnetometer 208 can be oriented in the opposite direction of the +y-axis of the second distal magnetometer 210 (see FIGS. 6A and 6B).

[0199]

[0236] In another modification, only the +x-axis of the first distal magnetometer 208 is oriented in the opposite direction of the +x-axis of the second distal magnetometer 210, or only the +y-axis of the first distal magnetometer 208 is oriented in the opposite direction of the +y-axis of the second distal magnetometer 210.

[0200]

[0237] By orienting the sensitivity axes (e.g., the x-axis and the y-axis) of the first distal magnetometer 208 and the second distal magnetometer 210 in opposite directions, the influence of a common magnetic field (e.g., the Earth's magnetic field) can be canceled so that the distortion or influence of the local magnetic field becomes more prominent, i.e., detectable.

[0201]

[0238] Reference is made to each of the magnetometers or magnetic sensors including the x-axis (e.g., +x-axis) and the y-axis (+y-axis). In the present disclosure, it is contemplated that references to the x-axis (e.g., +x-axis) or the y-axis (+y-axis) may also indicate a uniaxial magnetometer having only the x-axis or the y-axis for the magnetometer or magnetic sensor. Thus, references to four biaxial magnetometers (e.g., the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210) can also apply to eight uniaxial magnetometers (e.g., the first proximal magnetometer, the second proximal magnetometer, the third proximal magnetometer, the fourth proximal magnetometer, the first distal magnetometer, the second distal magnetometer, the third distal magnetometer, and the fourth distal magnetometer). In some embodiments, the distal sensing unit 136 can include four gradiometers each having two uniaxial magnetometers.

[0202]

[0239] In some variations, to increase or make more prominent the distortion or influence of the local magnetic field caused by the RSI or other ferromagnetic object, the specific common magnetic field measurement values obtained from the proximal gradiometer 200 (the first proximal magnetometer 202, the second proximal magnetometer 204, or a combination thereof) and the distal gradiometer 206 (the first distal magnetometer 208, the second distal magnetometer 210, or a combination thereof) can be canceled or reduced. For example, by canceling the influence of a common signal or common magnetic field (e.g., the Earth's magnetic field, or the distortion of the magnetic field caused by surrounding ferromagnetic hospital equipment), the distortion of the local magnetic field caused by an RSI or other ferromagnetic object near one gradiometer can generate a larger signal in this nearby gradiometer than in the other gradiometer positioned farther away.

[0203]

[0240] As will be discussed in more detail in the following section, one or more processors of the microcontroller 185 can be programmed to execute instructions stored in a memory unit for calculating a differential signal from the magnetic field measurement values obtained from the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210.

[0204]

[0241] Further, the distal sensing unit 136 may also include one or more operational amplifiers for amplifying the raw output signals from at least one of the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210. The operational amplifier can amplify such signals before the raw output signals from the magnetometer are sent to the ADC186 or ADC component of the microcontroller 185 within the handle 102. In some variations, one or more operational amplifiers can be mounted on the back side of the PCB within the distal sensing unit 136. For example, the first proximal operational amplifier and the second proximal operational amplifier can be mounted on the back side of the proximal rigid PCB 161 to amplify the signals from the first proximal magnetometer 202 and the second proximal magnetometer 204 respectively. Also, for example, the first distal operational amplifier and the second distal operational amplifier can be mounted on the back side of the distal rigid PCB 163 to amplify the signals from the first distal magnetometer 208 and the second distal magnetometer 210 respectively (see, for example, FIGS. 7A to 7C).

[0205]

[0242] At least one of the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210 can be an anisotropic magnetoresistive (AMR) sensor. For example, at least one of the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210 can be a two-axis AMR sensor. At least one of the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210 can be a solid-state AMR sensor designed for low magnetic field magnetic detection.

[0206]

[0243] As a more specific example, at least one of the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210 can be the HMC1052AMR sensor (part number HMC1052L-TR) distributed by Honeywell International Inc.

[0207]

[0244] In other variations, at least one of the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210 can be a three-axis AMR sensor.

[0208]

[0245] The AMR sensor can utilize a magnetoresistive material (e.g., permalloy) to function as a magnetometer. Permalloy is an alloy containing approximately 80% nickel and 20% iron. The resistance of the alloy depends on the angle between the metallization and the current direction. In a magnetic field, the magnetization rotates in the direction of the magnetic field, and the rotation angle depends on the magnitude of the external field. For example, the AMR sensor can include a permalloy thin film (e.g., NiFe magnetic film) whose electrical resistance varies with changes in the magnetic field.

[0209]

[0246] In some variations, the magnetometer can be any type of magnetoresistive sensor whose resistance changes in response to changes in the magnetic field along a given axis. In other variations, the magnetometer can be any type of vector magnetometer for measuring the vector components of the magnetic field.

[0210]

[0247] The magnetometer (any one of the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210) can include a communication interface capable of transmitting magnetic field measurement values using a communication protocol. The magnetometer can operate with a low-voltage power source such as a power source that provides a voltage lower than, for example, about 2.0V, 2.5V, 3.0V, 3.5V, 4.0V, 4.5V, 5.0V, 5.5V, or 6.0V. The magnetometer can be designed to be surface-mounted on the PCB of the distal sensing unit 136. For example, the first proximal magnetometer 202 and the second proximal magnetometer 204 can be surface-mounted on the proximal rigid PCB 161, and the first distal magnetometer 208 and the second distal magnetometer 210 can be surface-mounted on the distal rigid PCB 163.

[0211]

[0248] FIG. 6A also shows that the device 100 may include a distal LED 183. The distal LED 183 can be mounted at the distal end of an elongated flexible circuit 157 near the proximal rigid PCB 161. In other variations, the distal LED 183 can be mounted on the proximal rigid PCB 161, the distal flexible circuit 155, or the distal rigid PCB 163.

[0212]

[0249] The sensor housing 141 (see, e.g., FIGS. 1A, 1B, 3A, 3B, and 7C) may include a light transmission window or a light transmission section so that the light generated by the distal LED 183 can be visible to the operator through the endoscopy.

[0213]

[0250] The distal LED 183 can function in the same manner as the proximal LED 173. Also, the proximal LED 173 can generate the same light or light pattern as that generated by the distal LED 183 (and vice versa). The light or light pattern generated by the distal LED 183 and / or the proximal LED 173 can convey information regarding the battery life, standby indication, error alert, detection status, or a combination thereof of the device 100.

[0214]

[0251] FIGS. 5A - 5D and FIGS. 6A - 6B also show that the distal rigid PCB 163 can be rotated angularly relative to the proximal rigid PCB 161. The distal rigid PCB 163 can be maintained in this rotational or torsional configuration relative to the proximal rigid PCB 161.

[0215]

[0252] For example, the distal rigid PCB 163 can be maintained in this rotational or torsional configuration by the sensor housing 141 (not shown in FIG. 6A for clarity). Also, for example, the distal rigid PCB 163 can be maintained in this rotational or torsional configuration by one or more fixing components such as one or more clips, fasteners, space fillers, or combinations thereof.

[0216]

[0253] The distal rigid PCB 163 can be rotated by the twist angle 220. In some variations, the twist angle 220 can be about 45 degrees.

[0217]

[0254] In other variations, the twist angle 220 can be about 60 degrees, between about 45 degrees and 60 degrees, or less than about 45 degrees. In some variations, the twist angle 220 can be about 30 degrees.

[0218]

[0255] In some variations, the twist angle 220 can refer to the rotation angle of at least one of the second distal magnetometer 210 and the first distal magnetometer 208 with respect to the first proximal magnetometer 202.

[0219]

[0256] The distal rigid PCB 163 can be rotated about the distal flex circuit 155 that connects the proximal rigid PCB 161 to the distal rigid PCB 163. FIGS. 5A to 5D and FIGS. 6A to 6B show the distal rigid PCB 163 being rotated in the counterclockwise rotation direction when viewed from the proximal end of the distal sensing unit 136 to the distal end of the distal sensing unit 136. However, in the present disclosure, it is also conceivable that the distal rigid PCB 163 can be rotated in the clockwise rotation direction when viewed from the proximal end of the distal sensing unit 136 to the distal end of the distal sensing unit 136.

[0220]

[0257] In some variations, one of the axes of the magnetometers on the distal rigid PCB 163 can be aligned with one of the axes of the magnetometers on the proximal rigid PCB 161. For example, each of the x-axes of the first distal magnetometer 208 and the second distal magnetometer 210 can be axially aligned with the x-axes of the first proximal magnetometer 202 and the second proximal magnetometer 204, or positioned along the same axial plane as those x-axes. In these variations, the other axis of the magnetometer on the distal rigid PCB 163 may not be aligned with the other axis of the magnetometer on the proximal rigid PCB 161. For example, each of the y-axes of the first distal magnetometer 208 and the second distal magnetometer 210 can be not aligned or rotated (e.g., by the twist angle 220) with respect to the y-axes of the first proximal magnetometer 202 and the second proximal magnetometer 204.

[0221]

[0258] FIGS. 6A and 6B show axially aligning or planar aligning the x-axis of the magnetometer while not aligning the y-axis, but in the present disclosure, it is considered possible to axially align or planar align the y-axis of the magnetometer while not aligning the x-axis.

[0222]

[0259] By twisting, contorting, or otherwise rotating the distal rigid PCB 163 relative to the proximal rigid PCB 161, the magnetometer of the distal gradiometer 206 can provide magnetic field measurements along at least one additional axis. For example, if the magnetometer of the distal gradiometer 206 is a two-axis magnetometer (e.g., the magnetometer has an x-axis and a y-axis), and one of the axes of the magnetometer on the distal rigid PCB 163 is axially aligned or coplanarly aligned with the same axis on the proximal rigid PCB 161 (e.g., if the x-axis is substantially axially aligned with the x-axis on another substrate or positioned along the same axial plane as the x-axis), then by twisting, contorting, or otherwise rotating the distal rigid PCB 163, the magnetometer of the distal gradiometer 206 can provide magnetic field measurements along a third axis. In this example, the y-axis of the magnetometer on the distal rigid PCB 163 provides additional magnetic field measurements along the third axis.

[0223]

[0260] Further, FIGS. 5A - 5D and FIGS. 6A - 6B show twisting, contorting, or otherwise rotating the distal rigid PCB 163, but in the present disclosure, it is also contemplated that the proximal rigid PCB 161 can be twisted, contorted, or otherwise rotated.

[0224]

[0261] One technical advantage of twisting, contorting, or otherwise rotating one of the gradiometer circuit boards relative to the other (e.g., the distal rigid PCB 163 relative to the proximal rigid PCB 161) is that the applicant can use a smaller and less expensive two-axis magnetometer for sensing without the need to utilize an expensive and large three-axis magnetometer. As described above, by twisting, contorting, or otherwise rotating one of the gradiometer circuit boards, the magnetometer on the twisted or rotated board can be used as a pseudo "three-axis magnetometer" to provide magnetic field measurements along an additional axis. Thus, through twisting or rotation, the applicant can achieve three-dimensional detection sensitivity using a two-dimensional sensor.

[0225]

[0262] For example, in FIG. 6B, when the distal rigid PCB 163 is twisted or rotated, the y-axes (hereinafter referred to as Y1' and Y2' respectively) of the first distal magnetometer 208 and the second distal magnetometer 210 are substantially aligned with the y-vector components (Y1 and Y2 respectively) of the y-axes of the first proximal magnetometer 202 and the second proximal magnetometer 204, and new z-vector components (Z1 and Z2 respectively) that do not have counterparts on the proximal gradiometer 200. The new z-vector components can function as a pseudo third axis, and additional magnetic field measurements can be obtained along this additional axis.

[0226]

[0263] Another technical advantage of twisting, kinking, or otherwise rotating one of the gradiometer circuit boards relative to the other gradiometer circuit board (e.g., the distal rigid PCB 163 relative to the proximal rigid PCB 161) is that differential or comparative magnetic field values can be obtained not only from magnetometer pairs on the same gradiometer substrate but also from magnetometers on different gradiometer substrates. These differences or comparisons can be used to cancel or reduce the influence of the common magnetic field in order to increase or make more prominent the distortion or influence of the local magnetic field caused by RSI or other ferromagnetic objects.

[0227]

[0264] FIGS. 7A and 7B show an isometric view of another variant of the distal sensing part 136 of the metal detection device with the sensor housing 141 removed. In this variant, the distal rigid PCB 163, the distal flex circuit 155, and the proximal rigid PCB 161 can be replaced with a single rigid PCB 187. Also, in this variant, the magnetometers of the distal gradiometer 206 are not rotated relative to the magnetometers of the proximal gradiometer 200.

[0228]

[0265] As shown in FIGS. 7A and 7B, the axes of the first proximal magnetometer 202 and the second proximal magnetometer 204 are aligned or orthogonal to the axes of the first distal magnetometer 208 and the second distal magnetometer 210. For example, the x-axes of the first distal magnetometer 208 and the second distal magnetometer 210 can be axially aligned with the x-axes of the first proximal magnetometer 202 and the second proximal magnetometer 204, or positioned along the same axial plane as their x-axes. Also, for example, the y-axes of the first distal magnetometer 208 and the second distal magnetometer 210 can be orthogonal to the x-axes of the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210.

[0229]

[0266] FIGS. 7A and 7B show the circuit board of the distal sensing unit 136 as a single rigid PCB 187, but in the present disclosure, it is contemplated that the single rigid PCB 187 can also be implemented as two rigid PCBs connected by a flexible circuit. In this variant, it is a fixed component.

[0230]

[0267] The +x-axis of the first proximal magnetometer 202 can be oriented in the opposite direction to the +x-axis of the second proximal magnetometer 204. The +y-axis of the first proximal magnetometer 202 can be oriented in the opposite direction to the +y-axis of the second proximal magnetometer 204.

[0231]

[0268] The +x-axis of the first distal magnetometer 208 can be oriented in the opposite direction to the +x-axis of the second distal magnetometer 210, and the +y-axis of the first distal magnetometer 208 can be oriented in the opposite direction to the +y-axis of the second distal magnetometer 210.

[0232]

[0269] In some variants, the +x-axis of the second distal magnetometer 210 can be oriented in the opposite direction to the +x-axis of the first proximal magnetometer 202. In these and other variants, the +y-axis of the second distal magnetometer 210 can be oriented in the opposite direction to the +y-axis of the first proximal magnetometer 202.

[0233]

[0270] FIG. 7B is the same as FIG. 7A, except that the +x axis and +y axis are replaced with notations representing the measurements obtained by the magnetometers along these axes. The magnetic field measurement obtained along the positive x axis of the first distal magnetometer 208 is shown here as X1, the positive y axis of the first distal magnetometer 208 is shown here as Y1, the positive x axis of the second distal magnetometer 210 is shown here as X2, the positive y axis of the second distal magnetometer 210 is shown here as Y2, the positive x axis of the first proximal magnetometer 202 is shown here as X3, the positive y axis of the first proximal magnetometer 202 is shown here as Y3, the positive x axis of the second proximal magnetometer 204 is shown here as X4, and the positive y axis of the second proximal magnetometer 204 is shown here as Y4.

[0234]

[0271] The following equations 1 to 17 are equations devised by the applicant to calculate differential signals from the magnetic field measurements obtained from the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210. One or more processors of the microcontroller 185 can be programmed to execute instructions for calculating differential signals using any of the following equations. Equation 1 (also referred to as the on-axis local differential signal): (X1 + X2) - (X3 + X4) + ((Y1 + Y2) - (Y3 + Y4)) = X1 + X2 - X3 - X4 + Y1 + Y2 - Y3 - Y4 Equation 2 (also referred to as the on-axis global differential signal): (X1 + X4) - (X3 + X2) + ((Y1 + Y4) - (Y3 + Y2)) = X1 - X2 - X3 + X4 + Y1 - Y2 - Y3 + Y4 Equation 3 (also referred to as the on-axis Y local differential signal): (X1 + X2) - (X3 + X4) + ((Y1 - Y2) - (Y3 - Y4)) = X1 + X2 - X3 - X4 + Y1 - Y2 - Y3 + Y4 Equation 4 (also referred to as the on-axis Y global differential signal): (X1 + X4) - (X3 + X2) + ((Y1 - Y4) - (Y3 - Y2)) = X - X2 - X3 + X4 + Y1 + Y2 - Y3 - Y4 Equation 5 (also referred to as the on-axis ortho local differential signal): (X1 + X2) - (X3 + X4) - ((Y1 + Y2) - (Y3 + Y4)) = X1 + X2 - X3 - X4 - Y1 - Y2 - + Y3 - Y4 Equation 6 (also referred to as the on-axis orthogonal global difference signal): (X1 + X4) - (X3 + X2) - ((Y1 + Y4) - (Y3 + Y2)) = X1 - X2 - X3 + X4 - Y1 + Y2 + Y3 - Y4 Equation 7 (also referred to as the off-axis local difference magnetometer signal): (X1 + Y2) - (X3 + Y4) + ((Y1 + X2) - (Y3 + X4)) = X1 + X2 - X3 - X4 + Y1 + Y2 - Y3 - Y4 Equation 8 (also referred to as the off-axis ultra-local difference signal): (X1 + Y1) - (X2 + Y2) + ((Y3 + X3) - (Y4 + X4)) = X1 - X2 + X3 - X4 + Y1 - Y2 + Y3 - Y4 Equation 9 (also referred to as the off-axis global difference signal): (X1 + Y4) - (X3 + Y2) + ((Y1 + X4) - (Y3 + X2)) = X1 - X2 - X3 + X4 + Y1 - Y2 - Y3 + Y4 Equation 10 (also referred to as the off-axis ultra-global difference signal): (X1 + Y3) - (X2 + Y4) + ((Y1 + X3) - (Y2 + X4)) = X1 - X2 + X3 - X4 + Y1 - Y2 + Y3 - Y4 Equation 11 (also referred to as the off-axis orthogonal local difference signal): (X1 + Y2) - (X3 + Y4) - ((Y1 + X2) - (Y3 + X4)) = X1 - X2 - X3 + X4 - Y1 + Y2 + Y3 - Y4 Equation 12 (also referred to as the off-axis orthogonal global difference magnetometer signal): (X1 + Y4) - (X3 + Y2) - ((Y1 + X4) - (Y3 + X2)) = X1 + X2 - X3 - X4 - Y1 - Y2 + Y3 + Y4 Equation 13 (also referred to as the off-axis orthogonal ultra-local difference signal): (X1 + Y1) - (X2 + Y2) - ((Y3 + X3) - (Y4 + X4)) = X1 - X2 - X3 + X4 + Y1 - Y2 - Y3 + Y4 Equation 14 (also referred to as the off-axis orthogonal ultra-global difference signal): (X1 + Y3) - (X2 + Y4) - ((Y1 + X3) - (Y2 + X4)) = X1 - X2 - X3 + X4 - Y1 + Y2 + Y3 - Y4 Equation 15 (also referred to as the full global difference magnetometer signal): (X1 - X2) - (X3 - X4) + ((Y1 - Y2) - (Y3 - Y4)) = X1 - X2 - X3 + X4 + Y1 - Y2 - Y3 + Y4 Equation 16 (also referred to as the full global orthogonal difference signal): (X1 - X2) - (X3 - X4) - ((Y1 - Y2) - (Y3 - Y4)) = X1 - X2 - X3 + X4 - Y1 + Y2 + Y3 - Y4 Equation 17 (also referred to as the inverse global differential signal): (-X1 + X2) - (-X3 + X4) + ((-Y1 + Y2) - (-Y3 + Y4)) = -X1 + X2 + X3 - X4 - Y1 + Y2 + Y3 - Y4 Equation 18 (also referred to as the zeroed - sum signal or the "soup" signal): abs(X1 - X1zero) + abs(X2 - X2zero) + abs(X3 - X3zero) + abs(X4 - X4zero) + abs(Y1 - Y1zero) + abs(Y2 - Y2zero) + abs(Y3 - Y3zero) + abs(Y4 - Y4zero)

[0235]

[0272] As described above, Equation 2, Equation 9, Equation 13, and Equation 15 produced the same final result despite different initial groupings. Furthermore, Equation 1 and Equation 7 also produced the same final result.

[0236]

[0273] Equation 18 is the zeroed - sum of the absolute values of all magnetometers examined as potential high - sensitivity candidate signals (meaning that the initial measurement or reference measurement is subtracted from the currently ongoing signal). The signal obtained from Equation 18 is also referred to as the "soup" signal. Since this signal does not have the advantage of subtracting the common signal generated by moving through the Earth's magnetic field lines, this signal is much more susceptible to the influence of the signal generated by moving through the magnetic field lines indoors compared to Equation 2 or Equation 6, where the ratio of surgical needle detection to movement signal can be up to 4 - 5 times better.

[0237]

[0274] One advantage of calculating the differential signal using the equations disclosed in this specification is that the influence of the common magnetic field (such as the Earth's magnetic field, the influence of medical equipment in the operating room on the magnetic field, or the influence of the field due to movement) is canceled or reduced, and the distortion or influence of the local magnetic field becomes more prominent and occupies a larger portion of the overall signal.

[0238]

[0275] It should be noted that the positive and negative signs in the above equation take into account the fact that the magnetometer of device 100 is configured as shown in FIGS. 7A and 7B. For example, adding X1 and X2 actually subtracts two signals, and subtracting X1 from X2 actually adds two signals.

[0239]

[0276] In some environments, the differential signals calculated using equations 2, 9, 13, and 15 may be more prominent or significant than the signals calculated using other equations. In other environments, the differential signal calculated using equation 6 may be more prominent or significant than the signals calculated using other equations. Further, the differential signals calculated using equations 2, 9, 13, and 15 demonstrated good cancellation of signals generated by moving through the magnetic field lines in the operating room, compared to the distortion of the local magnetic field caused by small stainless steel RSI or other ferromagnetic objects.

[0240]

[0277] One or more processors of the microcontroller 185 can be programmed to calculate the differential signal using one of the above equations and to execute yet another instruction to switch or cycle between different equations. For example, one or more processors of the microcontroller 185 can be programmed to execute yet another instruction to calculate the differential signal using equation 2 (axial global differential signal), as well as equation 3 (axial Y local differential signal), equation 5 (axial orthogonal local differential signal), and equation 6 (axial orthogonal global differential signal).

[0241]

[0278] In the above, reference has been made to each of the magnetometers or magnetic sensors including the x-axis (e.g., +x-axis) and the y-axis (e.g., +y-axis). However, in the present disclosure, it is contemplated that a reference to the x-axis (e.g., +x-axis) or the y-axis (+y-axis) may also indicate a uniaxial magnetometer in which the magnetometer or magnetic sensor has only the x-axis or the y-axis. Accordingly, a reference to four two-axis magnetometers (e.g., the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210) can also apply to eight one-axis magnetometers (e.g., the first proximal magnetometer, the second proximal magnetometer, the third proximal magnetometer, the fourth proximal magnetometer, the first distal magnetometer, the second distal magnetometer, the third distal magnetometer, and the fourth distal magnetometer). In some embodiments, the distal sensing unit 136 can include four gradiometers each having two one-axis magnetometers. For example, in the above equations, the references to X1, X2, X3, X4, Y1, Y2, Y3, and Y4 can each indicate one axis of each of the first magnetometer, the second magnetometer, the third magnetometer, the fourth magnetometer, the fifth magnetometer, the sixth magnetometer, the seventh magnetometer, and any magnetometer.

[0242]

[0279] Also, a user or operator of the device 100 can provide user input (e.g., by turning the dial of one or more sensitivity wheels 115 forward or backward) and instruct one or more processors of the microcontroller 185 to switch between or cycle through different equations to calculate the differential signal.

[0243]

[0280] Referring again to FIG. 6B, when the distal rigid PCB 163 is twisted or rotated by a twist angle (e.g., 45 degrees), the additional equation (Equation 19) devised by the applicant for calculating the differential signal from the magnetic field measurement values obtained from the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210 is shown below. Equation 19 (also referred to as the axial distal torsional local differential signal): (X1 + X2) - (X3 + X4) + (1 / 2 * Y1 + 1 / 2 * Y2) - (Y3 + Y4) + (1 / 2 * Z1 + 1 / 2 * Z2) = X1 + X2 - X3 - X4 + (1 / 2 * Y1) + (1 / 2 * Y2) - Y3 - Y4 + (1 / 2 * Z1) + (1 / 2 * Z2)

[0244]

[0281] As will be discussed in more detail in the following section, one or more processors of the microcontroller 185 can be programmed to execute instructions for calculating a differential signal using any of the above equations.

[0245]

[0282] One or more processors of the microcontroller 185 can be programmed to execute instructions for calculating a differential signal using any combination of these equations at various points in time, or using other equations alone or in sequence, in order to evaluate the distortion of the local magnetic field from different perspectives over time. When a small field distortion passes by the device during use, these various perspectives can be combined at high speed to form an ensemble signal.

[0246]

[0283] One or more processors of the microcontroller 185 can be programmed to execute yet another instruction to apply one or more filters (e.g., high-pass filter and / or low-pass filter) to the differential signal to obtain a detection signal. It is also possible to apply a smoothing function to the detection signal.

[0247]

[0284] In other variations, one or more processors of the microcontroller 185 can be programmed to execute instructions for obtaining a detection signal by differentiating the differential signal, applying a derivative, or taking the derivative of the differential signal.

[0248]

[0285] One or more processors of the microcontroller 185 can be programmed to execute yet another instruction to compare the detection signal with a sensitivity or a detection threshold. Then, if the detection signal exceeds the sensitivity or the detection threshold, the output component (e.g., a speaker and / or one or more LEDs) can be instructed to generate a user output (e.g., a beep sound and / or bright light).

[0249]

[0286] In some variations, based on the sensitivity set by the operator of the device 100 (e.g., a surgeon or other medical professional), it is determined whether to apply or differentiate a signal filter. For example, the operator can turn the dial of one or more sensitivity wheels 115 forward, i.e., in the distal direction, until the sensitivity level or detection sensitivity of the device 100 reaches level 8 or higher. When the sensitivity level reaches level 8 or higher, one or more processors of the microcontroller 185 can be programmed to execute instructions to obtain a detection signal by applying one or more filters to the differential signal without differentiating.

[0250]

[0287] In another situation, the operator can turn the dial of one or more sensitivity wheels 115 backward, i.e., in the proximal direction, until the sensitivity level or detection sensitivity of the device 100 reaches level 7 or lower. When the sensitivity level reaches level 7 or lower, one or more processors of the microcontroller 185 can be programmed to execute instructions to obtain a detection signal by differentiating and applying one or more motion suppression algorithms.

[0251]

[0288] In any case, the detection signal is compared with the sensitivity or the detection threshold, and if the detection signal exceeds the sensitivity or the detection threshold, the one or more output components are instructed to generate a user output.

[0252]

[0289] As shown in FIGS. 7A and 7B, the distal sensing unit 136 can further include one or more operational amplifiers coupled to the rigid PCB 187. The one or more operational amplifiers can be configured to amplify the raw output signals from the various magnetometers before such signals are sent to the ADC 186 or ADC component of the microcontroller 185 within the handle 102. For example, the operational amplifiers can include a first proximal operational amplifier 212, a second proximal operational amplifier 214, a first distal operational amplifier 216, and a second distal operational amplifier 218. The first proximal operational amplifier 212 can amplify the raw output signal of the first proximal magnetometer 202. The second proximal operational amplifier 214 can amplify the raw output signal of the second proximal magnetometer 204. The first distal operational amplifier 216 can amplify the raw output signal of the first distal magnetometer 208. The second distal operational amplifier 218 can amplify the raw output signal of the second distal magnetometer 210.

[0253]

[0290] The first proximal operational amplifier 212 can be mounted on the back side of the circuit board (e.g., the rigid PCB 187 or the proximal rigid PCB 161) that supports the first proximal magnetometer 202. The second proximal operational amplifier 214 can be mounted on the back side of the circuit board (e.g., the rigid PCB 187 or the proximal rigid PCB 161) that supports the second proximal magnetometer 204. The first distal operational amplifier 216 can be mounted on the back side of the circuit board (e.g., the rigid PCB 187 or the distal rigid PCB 163) that supports the first distal magnetometer 208. The second distal operational amplifier 218 can be mounted on the back side of the circuit board (e.g., the rigid PCB 187 or the distal rigid PCB 163) that supports the second distal magnetometer 210.

[0254]

[0291] In other variations, the operational amplifiers (e.g., the first proximal operational amplifier 212, the second proximal operational amplifier 214, the first distal operational amplifier 216, the second distal operational amplifier 218, or combinations thereof) can be mounted on a circuit board housed in another part of the handle PCB 123 or the device 100.

[0255]

[0292] Figure 7C shows the sensor housing 141 covering the distal sensing unit 136. As described above, the sensor housing 141 may have a housing diameter 138 (see, for example, FIGS. 3A and 3B). The housing diameter 138 can be between about 3.0 mm and about 10.0 mm (for example, about 5.0 mm).

[0256]

[0293] Further, FIG. 7C shows that the fixed component 188 in the sensor housing 141 can fix those electronic components within the sensor housing 141 so that the electronic components (such as a magnetometer or an operational amplifier) in the sensor housing 141 do not separate or become detached when the distal sensing unit 136 is bent toward the shaft or the shaft 131 is rotated.

[0257]

[0294] In some variations, the fixed component 188 can be a polymer holder or a clip. In other variations, the fixed component 188 can be a fastener or other type of stopper.

[0258]

[0295] As described above, when the distal rigid PCB 163 is rotated, twisted, or rotated in another way with respect to the proximal rigid PCB 161, another example of the fixed component 188 can be used to maintain the distal rigid PCB 163 in a rotational configuration, a twisted configuration, or other rotational configurations.

[0259]

[0296] Figures 8A and 8B show rear close-up isometric views of the clock ring 107 at the lock position 108 and the unlock position 110, respectively. In FIGS. 8A to 8B, the left handle casing 101 is removed to clearly illustrate the components within the handle 102. FIGS. 8A to 8B show that a shaft can be coupled to the tube boss 113 positioned within the handle 102. By rotatably fixing the clock ring 107 to the tube boss 113, the rotation of the clock ring 107 can rotate the tube boss 113, thereby enabling the rotation of the shaft 131. The clock ring 107 can be defined by grooves or recesses that allow the operator to easily translate and rotate the clock ring 107.

[0260]

[0297] The lock ring 111 can be movably and rotatably fixed to the left handle casing 101 and the right handle casing 103 by a snap clip or other fastener. The lock ring 111 can include a plurality of lock splines 175 defined on the circumference of the lock ring 111. The clock ring 107 can include a plurality of interlock splines 174 for engaging the lock splines 175 on the lock ring 111.

[0261]

[0298] As shown in FIG. 8A, when the clock ring 107 is in the lock position 108, the clock ring 107 can be positioned to overlap the lock ring 111. The lock splines 175 on the lock ring 111 can be connected to the interlock splines 174 of the clock ring 107 to prevent the rotation of the clock ring 107.

[0262]

[0299] The clock ring 107 can be pushed or slid distally forward to the unlocked position 110. The clock ring 107 can be pushed or slid distally in the direction of the shaft 131, as shown by the enlarged arrow in FIG. 8A. For example, an operator (e.g., a surgeon or other medical professional) can hold the handle 102 with one hand and push or slide the clock ring 107 forward with the other hand.

[0263]

[0300] FIG. 8B shows that when the clock ring 107 is in the unlocked position 110, the interlocking spline 174 of the clock ring 107 can be released from the locking spline 175 of the clock ring 111. When the clock ring 107 is in the unlocked position 110, it can be rotated in the clockwise or counterclockwise direction. Rotating the clock ring 107 can rotate the tube boss 113 and the shaft 131 (as well as the flexible portion 145 and the distal sensing portion 136).

[0264]

[0301] Once the operator has rotated the clock ring 107 to the desired rotational position, the operator can lock the clock ring 107 in place by pulling or sliding the clock ring 107 back onto the locking ring 111. The operator can pull or slide the clock ring 107 in the direction of the proximal end of the handle back onto the locking ring 111, as shown by the enlarged arrow in FIG. 8B. The operator can continue to unlock and lock the clock ring 107 to achieve the desired rotation of the shaft 131.

[0265]

[0302] The operator can bend the flexible portion 145 by pulling the trigger 105 while rotating the clock ring 107. Since the flexible portion 145 can be bent while rotating the shaft 131, the operator can explore various body cavities or lumens with minimal movement of the user's hand and search behind or around organs. One technical advantage of the device 100 is the multiple degrees of freedom provided by the control mechanism disclosed herein.

[0266]

[0303] Figure 8C shows a close-up side view of the clock ring 107 in the lock position 108, and Figure 8D shows a cross-sectional view of the clock ring 107 in the lock position 108 along the section C-C shown in Figure 8C. Figure 8E shows a close-up side view of the clock ring 107 in the unlock position 110, and Figure 8F shows a cross-sectional view of the clock ring 107 in the unlock position 110 along the section D-D shown in Figure 8E. In Figures 8C to 8F, for clarity, the spring tube 137, the test bar 133, and the flexible circuit inside the shaft 131 are not shown.

[0267]

[0304] Figures 8C to 8F show that the nose cap 109 can be coupled to the tube boss 113 in the handle 102 by a snap clip or other fastener. The outer surface of the nose cap 109 can function as a support surface or a receiving surface for the clock ring 107 when the clock ring 107 is pushed distally or pulled proximally. Also, the nose cap 109 can function as a support surface for the clock ring 107 when the operator rotates the clock ring 107.

[0268]

[0305] Also, Figures 8D and 8F show that the shaft lock boss 177 can extend from the radially inner surface of the tube boss 113 to the engagement hole of the shaft 131. Thereby, the tube boss 113 can be coupled to the shaft 131 rotatably and translatably.

[0269]

[0306] Figures 8G and 8H show front close-up isometric views of the clock ring 107 in the locked position 108 and the unlocked position 110, respectively, with the nose cap 109 removed for clarity. Figures 8G and 8H show that the distal end 112 of the tube boss 113 can include a polygonal feature such as a substantially square block. This polygonal feature can engage a square notch (or another polygonal notch) in the clock ring 107 to rotatably couple the clock ring 107 to the tube boss 113.

[0270]

[0307] The tube boss 113 can include several clock ring detents 179 that can interfere with the mating features on the inner surface of the clock ring 107. The clock ring detents 179 can prevent the clock ring 107 from translating distally (i.e., unlocking) if insufficient force is applied by an operator (e.g., a surgeon or other medical professional). Once sufficient distal force is applied to the clock ring 107, the clock ring detents 179 deform or deflect to allow the clock ring 107 to translate distally (as shown by the enlarged arrow in Figure 8G) and rotate freely.

[0271]

[0308] Figure 8H shows that the clock ring 107 in the unlocked position 110 can rotate in a clockwise or counterclockwise direction of rotation. When the clock ring 107 is in the unlocked position 110, the clock ring detents 179 can be positioned behind or near the interference feature of the clock ring 107. The operator can apply sufficient force to pull the clock ring 107 rearward, i.e., proximally in the direction of the enlarged arrow (e.g., towards the proximal end of the handle), so that the clock ring detents 179 engage the interference feature of the clock ring 107 again if the operator wants to lock the shaft 131 in place.

[0272]

[0309] Figure 9A is an image of a metal detection device 100 used to detect a surgical suture needle 900 within a target body cavity. Figure 9B is an image of forceps 902 used to retrieve the surgical suture needle 900 upon detection by the metal detection device 100. Figures 9A and 9B show that the surgical suture needle 900 (or other RSI) can be retrieved from the target body using the forceps 902 or other surgical grasping devices upon detection by the device 100.

[0273]

[0310] In other variations not shown in the figures, the device 100 can include one or more permanent magnets, electromagnets, or combinations thereof. The one or more permanent magnets, electromagnets, or combinations thereof can be positioned within the distal sensing portion 136. The one or more permanent magnets, electromagnets, or combinations thereof can be positioned along a segment of the shaft 131. In these variations, detection of an RSI or ferromagnetic object can be performed with the electromagnet powered off or demagnetized. Once an RSI or other ferromagnetic object is detected by the device 100, the operator can turn on or magnetize the electromagnet and use the electromagnet and / or permanent magnets to magnetically attract the RSI or other ferromagnetic object.

[0274]

[0311] The electromagnet can have a variable magnetic field strength. In some variations, the operator can adjust the magnetic field strength of the electromagnet between one or more intensity levels based on the size or magnetism of the RSI or other ferromagnetic object.

[0275]

[0312] Figure 10A shows that the metal detection device 100 disclosed in this specification can be used to perform in-vivo detection of a surgical sponge 300 including sponges 302 with RFID tags and sponges 304 with metal marks tagged with one or more metal markers 306. In many cases, surgical sponges 300 rank first among all RSIs. In a certain study, sponge products accounted for 68% of all RSIs. See "Using a data-matrix-coded sponge counting system across a surgical practice: impact after 18 months" by Cima, Robert R., etc. (The Joint Commission Journal on Quality and Patient Safety 37.2 (2011): 51-AP3).

[0276]

[0313] The sponge 304 with a metal mark can be tagged with one or more ferromagnetic metal markers 306 or ferromagnetic metal tags or embedded in other ways. For example, the sponge 304 with a metal mark can include ferromagnetic beads, wires, threads, or combinations thereof in which the fabric or other materials constituting at least a part of this sponge are embedded or woven.

[0277]

[0314] The sponge 302 with an RFID tag may include an RFID tag 308 embedded in one or more layers of this sponge. The RFID tag 308 can be a passive RFID transponder. In other variations, the RFID tag 308 can be an active RFID transponder having its own power source.

[0278]

[0315] As shown in FIG. 10A, device 100 can include an RFID reader 310 within distal sensing portion 136. Distal sensing portion 136 can include various magnetometers and other electronic components disclosed herein, in addition to RFID reader 310. RFID reader 310 can be configured to read one or more RFID tags 308 within RFID-tagged sponge 302. RFID reader 310 is electrically coupled to or communicates electrically with microcontroller 185 such that microcontroller 185 can instruct RFID reader 310 to send interrogation pulses to one or more RFID tags 308 to obtain identification information or data regarding RFID-tagged sponge 302.

[0279]

[0316] By RFID reader 310, device 100 can ascertain RFID-tagged sponges 302 that are missing or remaining and can identify the location of such RFID-tagged sponges 302 within a patient's body cavity during surgery.

[0280]

[0317] In these and other variations, device 100 can also be used to identify the location of metal-marked sponges 304 that are in the wrong location or remaining, using the magnetometers and magnetic detection algorithms disclosed herein. For example, an operator or medical professional can adjust the sensitivity of device 100 using one or more sensitivity wheels 115 until device 100 generates a user output indicating the presence of metal-marked sponge 304 within the patient's body cavity.

[0281]

[0318] Figure 10B shows that the metal detection device 100 disclosed herein can also perform in vivo detection of ferromagnetic wires 312 such as surgical wires, guide wires, intravascular wires, or combinations thereof. In these and other variations, it is also possible to identify or detect the location of ferromagnetic catheters, sheaths, tubes, clips, other medical instruments, or fragments / segments thereof using the device 100.

[0282]

[0319] Further, it is also possible to perform in vivo detection of non-ferromagnetic wires, catheters, sheaths, tubes, clips, or other medical devices tagged with ferromagnetic tags or plates using the metal detection device 100 disclosed herein.

[0283]

[0320] Figure 11A shows another variation of the metal detection device 100 that includes a link cable 314. The link cable 314 extends from the device 100 (e.g., the proximal end or handle 102 of the device 100) and is electrically coupled to a closed-loop indicator 318 disposed outside the patient's body. The proximal end of a wire 312 such as a ferromagnetic guide wire or surgical wire can be extended outside the patient's body or otherwise exited from the patient's body and electrically coupled to the closed-loop indicator 318. The distal end of the wire or a segment of the wire 312 can be present within the patient's body. As shown in Figure 11A, the device 100 can include a conductive element 316 such as a conductive patch at its distal end. For example, the conductive element 316 can extend outside the sensor housing 141 from the distal sensing unit 136 or can be disposed along the shaft 131. The conductive element 316 can be electrically coupled or in electrical communication with the link cable 314.

[0284]

[0321] When the conductive element 316 contacts the wire 312 within the patient's body, the closed-loop indicator 318 can generate a signal or output (e.g., an audible or auditory command, a light or light pattern, or a combination thereof) to indicate that a closed loop has been achieved by the contact of the conductive element 316 with the wire 312 within the patient's body. This mechanism can be used to detect the position of the wire 312 within the patient. This is particularly important when the wire 312 is not visible to the surgeon or other medical professional, either directly or via endoscopy.

[0285]

[0322] Figure 11B shows that in vivo detection of ferromagnetic stent 320 or other support scaffolds can also be performed using the metal detection device 100 disclosed herein. The device 100 can be used to detect or verify the implantation site of the stent 320 or other support scaffold. It is also possible to detect non-ferromagnetic stents 320 or support scaffolds coated with a metallic coating or tagged with one or more metallic markers using the device 100.

[0286]

[0323] In some variations where a ferromagnetic or metal-marked wire, stent, or scaffold is used to support a patient's organ, lumen, or body cavity, the device 100 can be used not only to detect such a wire, stent, or scaffold (e.g., for a removal or inspection that may be performed), but also to detect or accurately identify the position of such an organ, lumen, or body cavity for another procedure.

[0287]

[0324] Figure 12 shows that the metal detection device 100 can be used when a patient's body cavity or part of the body is at least partially covered, shielded, or hidden by a magnetic blanket 322 or magnetic shield. In some variations, the magnetic blanket 322 can include a plurality of magnets embedded within the layers of the blanket or otherwise arranged.

[0288]

[0325] For example, when detecting RSI or remaining sharp objects within a patient's abdomen using device 100, the magnetic blanket 322 can be used to cover the patient's abdomen.

[0289]

[0326] Using the magnetic blanket 322 or shield, a controlled magnetic environment can be generated. Also, once the distal sensing portion 136 of device 100 enters the patient's body cavity, the magnetic blanket 322 or shield can be used to increase a specific signal or magnetic field distortion generated by a specific RSI (e.g., sponge 302 with RFID tag), and the detection sensitivity of the device is adjusted to capture the magnetic field distortion generated by the magnetic blanket 322 or shield.

[0290]

[0327] When performing in - body detection of RSI, implants, surgical tools, or combinations thereof within a patient's body cavity or a part of the body using device 100, the magnetic blanket 322 or shield can be used to at least partially cover, shield, or hide the patient's body cavity or a part of the body. For example, when performing in - body detection of a surgical needle, sponge 300, wire 312, stent 320 or other scaffolds, ferromagnetic or metallically marked catheters, sheaths, or other surgical instruments, or parts or combinations thereof using device 100, the magnetic blanket 322 or shield can be used to at least partially cover, shield, or hide the patient's body cavity or a part of the body.

[0291]

[0328] Alternatively or in addition to this, to make such a surgical needle, wire, or other tool more easily detectable by device 100 by magnetizing the specific surgical needle, wire, or other tool, it is also possible to use the magnetic blanket 322 to wrap such a surgical needle, wire, or other tool before surgery.

[0292]

[0329] FIG. 13 is a signal diagram representing the distal sensing portion 136 of device 100 as it passes over a surgical suture needle (e.g., a 5-0 13 mm surgical suture needle). In the situation shown in FIG. 13, device 100 may be operating in a high-speed high-sensitivity mode. In this mode, the dial of one or more sensitivity wheels 115 can be turned forward, i.e., distally, so that the sensitivity level becomes higher than the starting default level (e.g., level 8, 9, 10, or 11). In this mode, one or more processors of microcontroller 185 can be programmed to execute instructions to apply one or more signal filters (e.g., a high-pass filter, a low-pass filter, or a combination thereof) to the differential signal to obtain a detection signal. Also, each time step in FIG. 13 can represent approximately 1.5 milliseconds.

[0293]

[0330] For example, one or more processors of microcontroller 185 can be programmed to first execute instructions to calculate a differential signal from the magnetic field measurements obtained from the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210. More specifically, one or more processors of microcontroller 185 can be programmed to execute instructions to calculate the differential signal using any of the above equations 1-18. In the situation shown in FIG. 13, the differential signal is calculated using equation 2 (also referred to as the axial global differential signal).

[0294]

[0331] One or more processors of microcontroller 185 can be programmed to execute another instruction to apply a high-pass filter to the differential signal (e.g., the axial global differential signal). The high-pass filter can remove the low-frequency noise of the differential signal. For example, the high-pass filter can remove drift and offset and return the average signal to zero.

[0295]

[0332] One or more processors of the microcontroller 185 can be programmed to execute additional instructions for applying several low-pass filters to the high-pass filtered signal. For example, one or more processors of the microcontroller 185 can be programmed to execute additional instructions for applying a second-order low-pass filter (also referred to as a two-pole filter) to remove high-frequency noise from the high-pass filtered signal. The low-pass filter or the second-order filter (or two-pole filter) can cut off the high-frequency noise more aggressively. In some variations, the high-pass filter can have a cut-off of 5.5 Hz and the low-pass filter can have a cut-off of 10 Hz.

[0296]

[0333] One or more processors of the microcontroller 185 can be programmed to execute another instruction for obtaining a detection signal by taking the absolute value of the low-pass filtered signal and applying a smoothing function (smoothing point = 10) to the low-pass filtered signal.

[0297]

[0334] One or more processors of the microcontroller 185 can be programmed to execute additional instructions for comparing the detection signal with a sensitivity threshold or a detection threshold. Further, one or more processors of the microcontroller 185 can be programmed to execute another instruction for instructing an output component (such as a speaker and / or an LED light) to generate a user output (such as a beep sound, a flash light, a light with increasing intensity, or a combination thereof) when the detection signal exceeds the sensitivity or the detection threshold.

[0298]

[0335] As shown in FIG. 13, when the distal sensing unit 136 passes over the surgical suture needle, the detection signal exceeds the detection threshold. Also, the inset in FIG. 13 shows that the filter steps generate an accurate detection signal that does not cause false positive detections to cope with the signal noise before detection.

[0299]

[0336] Further, FIG. 13 shows that when the magnetometer is periodically reset to remove settling events or level changes, the sensitivity level of device 100 can be lowered and the sensitivity or detection threshold can be automatically increased.

[0300]

[0337] FIG. 14 is a signal diagram showing that an operator (e.g., a surgeon or other medical professional) adjusts the sensitivity level of device 100 while simultaneously sliding test bar slider 117 forward to test the functionality of the device using test bar 133. In the situation shown in FIG. 14 (e.g., a sensitivity level of 7 or less), device 100 may be operating in a low-speed, low-sensitivity mode. In this mode, one or more processors of microcontroller 185 can be programmed to execute instructions to apply a derivative to the differential signal and apply a motion-blocking algorithm to obtain a detection signal. The motion-blocking algorithm or motion-blocker signal will be discussed in more detail in the following section (see, for example, FIGS. 17A and 17B). Also, each time step in FIG. 14 can represent approximately 28 milliseconds.

[0301]

[0338] FIG. 14 shows that the operator can increase the sensitivity level (i.e., lower the sensitivity threshold) by turning the dial of one or more sensitivity wheels 115 forward, i.e., distally. The operator can increase the sensitivity level (e.g., from level 0 to level 4) to ensure that test bar 133 is detected by distal detector 136.

[0302]

[0339] Each spike in the detection signal can represent a case where the distal segment of test bar 133 exits spring tube 137 and extends into sensor housing 141 and is close to the magnetometer. A large spike can be a case where test bar 133 further enters sensor housing 141 and approaches the magnetometer. A small spike can be a case where the distal segment of test bar 133 slightly extends into sensor housing 141 or retracts into spring tube 137.

[0303]

[0340] FIG. 15 is a signal diagram representing the distal sensing unit 136 passing over a portion of the metal guide wire. For example, the guide wire can be a straight fixed core guide wire made partially of stainless steel. As shown in FIG. 15, when the distal sensing unit 136 passes over a portion of the metal guide wire, the detection signal may exceed the sensitivity threshold or detection threshold. In this example, when the distal sensing unit 136 passes over the metal guide wire, the distal sensing unit 136 is within 10 mm of the metal guide wire.

[0304]

[0341] The output component (e.g., speaker 181, proximal LED 173, distal LED 183, or a combination thereof) can generate a user output (e.g., a beep sound, a flash of light or a bright light, or a combination thereof) to notify the user that the distal sensing unit 136 has passed over the metal guide wire.

[0305]

[0342] In the situation shown in FIG. 15, the device 100 may be operating in a low-speed and low-sensitivity mode. In this mode, the dial of one or more sensitivity wheels 115 can be turned backward, i.e., proximally, so that the sensitivity level is lower than the starting default level (e.g., level 7 or below). Also, in this mode, one or more processors of the microcontroller 185 can be programmed to execute instructions to apply a derivative to the differential signal to obtain the detection signal. Also, each time step in FIG. 15 can represent approximately 28 milliseconds.

[0306]

[0343] FIG. 16A is a signal diagram showing the effect on the detection signal when the trigger 105 is pulled. As shown in FIG. 16A, the trigger 105 is pulled twice in succession, then after a short interval without actuating the trigger 105, it is pulled three more times in succession. Each time the trigger 105 is pulled, a spike in the trigger potentiometer signal is observed. As shown in FIG. 16A, during this period, one or more sensitivity wheels 115 and the probe slider 117 are not actuated. This is evident from the flat sensitivity wheel potentiometer signal and the probe potentiometer signal, respectively.

[0307]

[0344] In the situation shown in FIG. 16A, device 100 may be operating in a low-speed, low-sensitivity mode. In this mode, the dials of one or more sensitivity wheels 115 can be turned backward or proximally so that the sensitivity level is lower than the starting default level (e.g., level 7 or below). Also, in this mode, one or more processors of microcontroller 185 can be programmed to execute instructions to apply a derivative to the differential signal to obtain a detection signal. Also, each time step in FIG. 16A may represent approximately 28 milliseconds.

[0308]

[0345] FIG. 16A shows that the detection signal jumps or spikes each time the trigger 105 is pulled, even when an RSI or other ferromagnetic sharp object is not detected. The detection signal may jump or spike as a result of the distal sensing unit 136 moving in response to the trigger being pulled and the flexible portion 145 bending or curving.

[0309]

[0346] FIG. 16B is a signal diagram showing that device 100 automatically raises the sensitivity threshold or detection threshold in response to the situation where the trigger shown in FIG. 16A is pulled. For example, one or more processors of microcontroller 185 can be programmed to execute instructions to observe the motion signal from the accelerometer or gyroscope of IMU 159 disposed in the distal sensing unit 136. If the motion signal exceeds a preset or predetermined motion threshold, one or more processors of microcontroller 185 can be programmed to execute another instruction to automatically raise the sensitivity threshold or detection threshold to lower the sensitivity level or detection sensitivity of device 100. As shown in FIG. 16B, when the trigger 105 is pulled continuously, the sensitivity or detection threshold is raised between two cases (pulling the trigger twice and pulling the trigger three times).

[0310]

[0347] Figure 16C is another signal diagram showing that the device 100 automatically raises the sensitivity threshold or detection threshold in response to the situation where the trigger shown in Figure 16A is pulled. One or more processors of the microcontroller 185 can be programmed to execute instructions for observing the trigger speed signal from the trigger potentiometer 171 indicating the trigger speed. If the trigger speed signal is preset or exceeds a predetermined speed threshold (for example, when the trigger 105 is pulled too fast), one or more processors of the microcontroller 185 can be programmed to execute another instruction for automatically raising the sensitivity threshold or detection threshold so as to lower the sensitivity level or detection sensitivity of the device 100. As shown in Figure 16C, when the trigger 105 is continuously pulled, the sensitivity or detection threshold is raised between two cases.

[0311]

[0348] Figures 17A and 17B are signal diagrams showing a motion blocking signal or motion blocker signal used to reduce the detection signal in the event that the distal sensing unit 136 undergoes sudden motion. In the situations shown in Figures 17A and 17B, the device 100 may be operating in a low-speed low-sensitivity mode. In this mode, the dial of one or more sensitivity wheels 115 can be turned backward, i.e., proximally, so that the sensitivity level becomes lower than the starting default level (for example, below level 7). Also, in this mode, one or more processors can be programmed to execute instructions for applying a derivative to the differential signal to obtain the detection signal. Also, each time step in Figures 17A and 17B can represent approximately 28 milliseconds.

[0312]

[0349] FIG. 17A shows the raw motion signal calculated from the data received from the accelerometer and gyroscope of the IMU 159. The device 100 can calculate a motion blocker signal for reducing the detection signal using the raw motion signal. For example, one or more processors of the microcontroller 185 can be programmed to execute instructions for calculating the motion blocker signal by comparing the raw motion signal with a motion threshold. For example, if the raw motion signal is below the motion threshold, the motion blocker signal can be set to 1. However, the motion blocker signal can be increased based on the magnitude of the raw motion signal. If the raw motion signal is above the motion threshold, the magnitude of the motion blocker signal can substantially track the magnitude of the raw motion signal. One or more processors of the microcontroller 185 can be programmed to execute another instruction to divide the detection signal by the motion blocker signal to obtain a more motion-tolerant detection signal. FIG. 17A shows the detection signal after motion blocking. Also, FIG. 17A gives an exemplary detection threshold and shows how the (motion-blocked) detection signal maintains a state below the detection threshold, thereby preventing false positive detections.

[0313]

[0350] FIG. 17B shows the detection signal without performing the aforementioned motion blocking step. As shown in FIG. 17B, the (non-motion-blocked) detection signal exceeds the same detection threshold shown in FIG. 17A multiple times, thereby increasing the likelihood of a large number of false positive detections.

[0314]

[0351] Figure 18 shows a method 500 for detecting a magnetic object within a patient. Method 500 includes, at step 502, introducing a portion of a metal detection device 100 into the patient's body. The metal detection device 100 can include a handle 102, a shaft 131 extending from the handle 102, a microcontroller 185 including one or more processors and a memory unit, an output component, and a distal detection unit 136 positioned distally of the shaft 131. The distal detection unit 136 can include a proximal gradiometer 200 including a first proximal magnetometer 202 and a second proximal magnetometer 204, and a distal gradiometer 206 including a first distal magnetometer 208 and a second distal magnetometer 210.

[0315]

[0352] Method 500 can also include, at step 504, using one or more processors to calculate a differential signal from magnetic field measurements obtained from the first proximal magnetometer 202, the second proximal magnetometer 204, the first distal magnetometer 208, and the second distal magnetometer 210.

[0316]

[0353] Method 500 can also include, at step 506, using one or more processors to apply at least one of a signal filter and a derivative to the calculated differential signal to obtain a detection signal. Method 500 can further include, at step 508, using one or more processors to compare the detection signal with a sensitivity threshold or a detection threshold. Method 500 can include, at step 510, generating a user output using the output component if the detection signal exceeds the sensitivity or the detection threshold. When the distal detection unit 136 passes by or over a ferromagnetic RSI or another ferromagnetic object, the detection signal may exceed the sensitivity or the detection threshold.

[0317]

[0354] Figure 19 shows another method 600 for detecting a magnetic object within a patient's body. Method 600 may include, at step 602, introducing a portion of the metal detection device 100 (e.g., the distal segment of the metal detection device 100) into the patient's body. The metal detection device 100 may include a handle 102, a shaft 131 extending from the handle 102, a distal sensing portion 136 positioned distally of the shaft 131, a flexible portion 145 connecting the shaft 131 to the distal sensing portion 136, a microcontroller 185 including one or more processors and a memory unit, and an output component.

[0318]

[0355] The distal sensing portion 136 may include a plurality of magnetometers. For example, the distal sensing portion 136 may include a proximal gradiometer 200 including a first proximal magnetometer 202 and a second proximal magnetometer 204, and a distal gradiometer 206 including a first distal magnetometer 208 and a second distal magnetometer 210.

[0319]

[0356] Method 600 may also include, at step 604, bending the flexible portion 145 by pulling a trigger 105 on the handle 102 when at least a portion of the distal sensing portion 136 and the flexible portion 145 are within the patient's body. Method 600 may further include, at step 606, calculating a detection signal from magnetic field measurements obtained from the plurality of magnetometers using one or more processors. Calculating the detection signal may further include calculating a differential signal from magnetic field measurements obtained from the first proximal magnetometer, the second proximal magnetometer, the first distal magnetometer, and the second distal magnetometer using one or more processors. Further, method 600 may include applying at least one of a signal filter and a derivative to the calculated differential signal to obtain the detection signal.

[0320]

[0357] Method 600 may further include, at step 608, comparing the detection signal with a sensitivity threshold or a detection threshold using one or more processors. Method 600 may also include, at step 610, generating a user output using an output component if the detection signal exceeds the sensitivity threshold or the detection threshold. When the distal sensing unit 136 passes by or over a ferromagnetic RSI or another ferromagnetic object, the detection signal may exceed the sensitivity or detection threshold.

[0321]

[0358] Method 600 may also include determining a trigger speed based on data obtained from a trigger potentiometer 171 within the handle 102. The trigger potentiometer 171 may be coupled to the trigger 105. Method 600 may further include adjusting the sensitivity or detection threshold based on the trigger speed using one or more processors.

[0322]

[0359] FIG. 20 shows a method 700 for testing the functionality of the metal detection device 100. Method 700 may include, at step 702, providing the metal detection device 100. The metal detection device 100 may include a handle 102, a shaft 131 extending from the handle 102, a distal sensing unit 136 positioned distally of the shaft 131, a flexible portion 145 connecting the shaft 131 to the distal sensing unit 136, a microcontroller 185 including one or more processors and a memory unit, and an output component.

[0323]

[0360] The distal sensing unit 136 may include a plurality of magnetometers. For example, the distal sensing unit 136 may include a proximal gradiometer 200 including a first proximal magnetometer 202 and a second proximal magnetometer 204, and a distal gradiometer 206 including a first distal magnetometer 208 and a second distal magnetometer 210.

[0324]

[0361] Method 700 may also include sliding the test bar slider 117 on the handle 102 distally toward the shaft 131. In step 704, when the test bar slider 117 is slid, the distal segment of the test bar 133 housed within the lumen extending through the shaft 131 translates into the sensor housing 141.

[0325]

[0362] When method 700 translates the distal segment of the test bar 133 into the sensor housing 141, in step 706, method 700 may include using one or more processors to calculate a detection signal from the magnetic field measurements obtained from the plurality of magnetometers. Method 700 may further include, in step 708, using one or more processors to compare the detection signal to a sensitivity threshold or a detection threshold. Method 700 may also include, in step 710, using an output component to generate a user output if the detection signal exceeds the threshold.

[0326]

[0363] Each of the variations or embodiments described and illustrated herein has separate components and features, and they can be easily separated from or combined with the features of any of the other variations or embodiments. Modifications can be made to adapt a particular situation, material, composition of matter, process, one or more process acts or steps to the one or more objects, spirit, or scope of the present invention.

[0327]

[0364] The methods recited herein can be performed in any logically possible order of the recited events, as well as in the order of the recited events. Also, additional steps or acts can be provided or steps or acts can be deleted to achieve the desired result.

[0328]

[0365] Furthermore, when a range of values is given, all values between the upper and lower limits of that range, as well as any other recited values within that range or values within that range, are encompassed within the present invention. Also, optional features of the described invention can be described and claimed independently of or in combination with any one or more of the features described herein. For example, a description of a range from 1 to 5 should be considered to disclose subranges such as from 1 to 3, from 1 to 4, from 2 to 4, from 2 to 5, from 3 to 5, etc., as well as individual numbers within that range such as 1.5 and 2.5, and all increments or partial increments therebetween.

[0329]

[0366] All existing subject matter (e.g., publications, patents, patent applications) referred to herein is incorporated by reference in its entirety into this application, except when the subject matter may conflict with the subject matter of the present invention (in which case the matter present herein shall prevail). The articles referred to are provided only for their disclosure prior to the filing date of this application. Nothing in this specification is to be construed as an admission that the present invention is not entitled to antedate such material by virtue of prior invention.

[0330]

[0367] References to a single article include the possibility that there may be a plurality of the same articles. More specifically, as used in this specification and the appended claims, the singular forms "a", "an", "said", and "the" include plural referents unless the context clearly dictates otherwise. It should also be noted that the claims may be drafted to exclude optional elements. Accordingly, this description is intended to function as a basis for using exclusive terms such as "solely", "only", etc. in combination with the recitation of claim elements, or for using "negative" limitations. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0331]

[0368] When understanding the scope of the present disclosure, the term "comprising" and its derivatives, as used herein, are intended to be open-ended terms that identify the presence of the recited features, elements, components, groups, integers, and / or steps, but do not exclude the presence of other unrecited features, elements, components, groups, integers, and / or steps. The foregoing also applies to terms having similar meanings such as the terms "including", "having", and their derivatives. Further, the terms "part", "section", "portion", "member", "element", or "component", when used in the singular, can have two meanings, a single part or a plurality of parts. As used herein, the directional terms "forward, rearward, above, downward, vertical, horizontal, below, transverse, laterally, and vertically", and other similar directional terms, indicate the position or direction of a device or apparatus that is being translated or moved. Finally, terms of degree such as "substantially", "about", and "approximately", as used herein, mean a reasonable amount of deviation from the specified value such that the end result does not vary substantially or greatly (e.g., a deviation of up to ±0.1%, ±1%, ±5%, or ±10% if such variation is appropriate).

[0332]

[0369] The present disclosure is not intended to be limited to the specific forms described, but is intended to cover alternatives, modifications, and equivalents of the variations or embodiments described herein. Further, the scope of the present disclosure fully encompasses other variations or embodiments that may become apparent to those skilled in the art in light of the present disclosure.

Claims

1. A handle, a shaft extending from the handle, a distal sensing unit positioned distally of the shaft, a proximal gradiometer including a first proximal magnetometer and a second proximal magnetometer, a distal gradiometer including a first distal magnetometer and a second distal magnetometer, a proximal rigid printed circuit board (PCB) to which the first proximal magnetometer and the second proximal magnetometer are coupled, a distal rigid PCB to which the first distal magnetometer and the second distal magnetometer are coupled, a distal flexible circuit disposed between the proximal rigid PCB and the distal rigid PCB and connecting the proximal rigid PCB to the distal rigid PCB, and a distal sensing unit including the distal rigid PCB rotated angularly by a twist angle with respect to the proximal rigid PCB about the distal flexible circuit, an output component configured to generate a user output to notify the user about the detected object, a metal detection device comprising a microcontroller including one or more processors and a memory unit, wherein the one or more processors are configured to calculate a differential signal from magnetic field measurements obtained from the first proximal magnetometer, the second proximal magnetometer, the first distal magnetometer, and the second distal magnetometer, apply at least one of a signal filter and differentiation to the calculated differential signal to obtain a detection signal, compare the detection signal with a threshold value, and command the output component to generate the user output when the detection signal exceeds the threshold value, and is programmed to execute instructions stored in the memory unit for that purpose.

2. The metal detection device according to claim 1, wherein the signal filter includes at least one of a high-pass filter and a low-pass filter.

3. The metal detection device according to claim 1, wherein the first proximal magnetometer, the second proximal magnetometer, the first distal magnetometer, and the second distal magnetometer are each two-axis magnetometers having an x-axis and a y-axis.

4. The metal detection device according to claim 3, wherein each of the first proximal magnetometer and the second proximal magnetometer includes at least a +x-axis and a +y-axis, the +x-axis of the first proximal magnetometer is oriented in a direction opposite to the +x-axis of the second proximal magnetometer, and the +y-axis of the first proximal magnetometer is oriented in a direction opposite to the +y-axis of the second proximal magnetometer.

5. Each of the first distal magnetometer and the second distal magnetometer includes at least a +x axis and a +y axis, the +x axis of the first distal magnetometer is directed in a direction opposite to the +x axis of the second distal magnetometer, and the +y axis of the first distal magnetometer is directed in a direction opposite to the +y axis of the second distal magnetometer. The metal detection device according to claim 3.

6. Each of the second distal magnetometer and the first proximal magnetometer includes at least a +x axis and a +y axis, the +x axis of the second distal magnetometer is directed in a direction opposite to the +x axis of the first proximal magnetometer, and the +y axis of the second distal magnetometer is directed in a direction opposite to the +y axis of the first proximal magnetometer. The metal detection device according to claim 3.

7. At least one of the axes of the first proximal magnetometer and the second proximal magnetometer is not orthogonal to at least one of the axes of the first distal magnetometer and the second distal magnetometer. The metal detection device according to claim 3.

8. The torsion angle is about 45 degrees. The metal detection device according to claim 1.

9. The torsion angle is about 60 degrees. The metal detection device according to claim 1.

10. The torsion angle is about 30 degrees. The metal detection device according to claim 1.

11. The axes of the first proximal magnetometer and the second proximal magnetometer are aligned or orthogonal to the axes of the first distal magnetometer and the second distal magnetometer. The metal detection device according to claim 3.

12. The distal detection unit is covered with a sensor housing, the sensor housing has a housing diameter, and the housing diameter is between about 3.0 mm and about 10.0 mm. The metal detection device according to claim 1.

13. The housing diameter is about 5.0 mm. The metal detection device according to claim 12.

14. The sensor housing has a housing length dimension between about 40.0 mm and about 50.0 mm. The metal detection device according to claim 12.

15. The microcontroller is housed within the handle. The metal detection device according to claim 1.

16. The distal detection unit further includes one or more operational amplifiers, and the one or more operational amplifiers are configured to amplify raw output signals from at least one of the first proximal magnetometer, the second proximal magnetometer, the first distal magnetometer, and the second distal magnetometer before such signals are sent to an analog-to-digital converter (ADC) or ADC component of the microcontroller within the handle. The metal detection device according to claim 1.

17. The metal detection device according to claim 1, further comprising a flexible portion coupling the distal detection unit to the shaft, the flexible portion being bendable and including a straight configuration and a bent configuration, and the distal detection unit being positioned closer to the shaft when the flexible portion is in the bent configuration.

18. The metal detection device according to claim 17, wherein the flexible portion is partially made of a thermoplastic elastomer.

19. The metal detection device according to claim 17, wherein the flexible portion is partially made of Pebax (registered trademark).

Images