Vascular monitoring system

Abstract

To provide an improved vascular monitoring system.SOLUTION: A Doppler blood flow monitoring device 150 includes a signal generation module, a signal reception module, a signal filtration module, a signal conversion module, at least one speaker, and a user interface. The signal generation module is configured to send a signal to a probe positioned in a probe receptacle on a vascular coupler positioned about a patient's vessel. The signal reception module is configured to receive a return signal from the probe. The signal filtration module is configured to filter the return signal. The signal conversion module is configured to convert the filtered signal into an audible indication and a visual indication corresponding to a characteristic of blood flow in the patient's vessel. The at least one speaker is configured to emit the first audible indication. Additionally, the user interface is configured to display the visual indication.SELECTED DRAWING: Figure 1B

Description

[Background technology]

[0001]

[0001] Free flaps are commonly used in plastic and reconstructive surgery, such as for breast reconstruction. In free flap tissue surgery, a free flap (e.g., tissue and / or muscle and its associated arteries and veins) is removed from one part of the body, or donor site, and reattached to another part of the body, or recipient site. The arteries and veins of the transplanted tissue and / or muscle are then anastomosed to the native arteries and veins to establish blood circulation in the transplanted free flap (e.g., tissue and / or muscle).

[0002] Anastomosis of free flap tissue to native tissue is typically performed using microvascular techniques, including microscopic visualization. Several surgical instruments and techniques have been developed to aid in anastomosis. One known system for performing anastomosis is the anastomotic coupler described in U.S. Pat. No. 7,192,400, the disclosure of which is incorporated herein by reference. The anastomotic coupler is a surgical instrument that allows surgeons to more easily and effectively join the ends of two blood vessels. The coupler involves the use of two ring-shaped fastener portions, each of which secures a portion of the blood vessel to be attached. Each fastener portion further includes a series of pins and corresponding holes for receiving the pins to close and connect the portions, and thus the blood vessel (see FIGS. 7A, 7C, and 7D).

[0003]

[0003] Although free flap surgery has a history of success, the highly undesirable outcome of flap failure remains a possibility. One of the primary causes of flap failure is a lack of blood supply to the valve tissue after the free flap is reattached at the recipient site. Common barriers to valve circulation include vascular blockage, bleeding, or infection. Lack of adequate blood supply to the valve tissue results in tissue necrosis. However, if the valve is not properly circulating, it can be saved, or salvaged. After recognizing the lack of blood flow, the time window in which the valve can be salvaged is very small. Therefore, it is important to quickly recognize the lack of blood flow in the implanted valve.

[0004]

[0004] Handheld Doppler probes, which are typically permanently placed at the distal tip of a pen-like device rather than being placed or left inside the body, are useful for monitoring blood flow, but they have several drawbacks, including the inability to reliably place the probe around a blood vessel.

[0005]

[0005] After microvascular surgery, monitoring the surgical area is crucial to ensure that blood flow is maintained at the desired level and that problems such as thrombosis do not occur. If thrombosis occurs, the transplanted tissue will die. Furthermore, indirect methods for monitoring the function of blood flow in microvascularly treated vessels are often inadequate. For example, surface temperature measurement, transcutaneous PO2 monitoring, photoplethysmography, and laser Doppler flowmetry have been employed. However, these approaches generally require an accessible, exposed portion of the valve. Furthermore, implanted free tissue grafts and intraoral valves cannot be effectively monitored using these methods. Summary of the Invention

[0006]

[0006] The present disclosure provides improved vascular monitoring systems, devices and methods that improve accessibility, detectability and / or reliability in detecting blood flow to confirm vascular patency at an anastomosis site.

[0007] In one exemplary embodiment, a Doppler blood flow monitor device includes a signal generation module, a signal receiving module, a signal filter module, a signal conversion module, at least one speaker, and a user interface. The signal generation module is configured to transmit a signal to a probe disposed in a probe receptacle of a vascular coupler disposed around a patient's blood vessel. The signal receiving module is configured to receive a return signal from the probe. The signal filter module is configured to filter the return signal. The signal conversion module is configured to convert the filtered signal into an audible indication and a visual indication corresponding to a characteristic of blood flow within the patient's blood vessel. The at least one speaker is configured to emit a first audible indication. Additionally, the user interface is configured to display a visual indication.

[0008] In another exemplary embodiment, a Doppler blood flow monitoring system includes a vascular coupler, a transducer, and a monitor. The vascular coupler is positioned around a blood vessel of a patient. The transducer is attached to the vascular coupler. The monitor is configured to generate a signal to transmit to the transducer, and the transducer is configured to emit an ultrasound signal based on the signal generated by the monitor. Additionally, the ultrasound signal is transmitted through the patient's blood vessel. The monitor is further configured to receive a return signal from the transducer and convert the return signal into a first representation and a second representation corresponding to a characteristic of blow flow in the patient's blood vessel.

[0009] In another exemplary embodiment, a remote monitoring system includes a monitor and a remote database. The monitor is configured to generate a signal to transmit to a transducer disposed within a vascular coupler. The vascular coupler is disposed around a patient's blood vessel, and the transducer is configured to emit an ultrasound signal based on the signal generated by the monitor, the ultrasound signal being transmitted through the patient's blood vessel. The monitor is further configured to receive a return signal from the transducer and convert the return signal into a first representation and a second representation corresponding to a characteristic of the blowflow through the patient's blood vessel. The remote database is configured to receive one or more files associated with the first representation and store one or more files associated with the first representation, the one or more files being remotely accessible via a user device.

[0010]

[0010] It is therefore an advantage of the present disclosure to improve the accessibility of blood flow data.

[0011]

[0011] It is another advantage of the present disclosure to improve detection of blood flow to confirm vascular patency.

[0012] It is another advantage of the present disclosure to provide remote monitoring of blood flow at the anastomosis site.

[0013] It is a further advantage of the present disclosure to reduce background noise from an audio signal representing blood flow within a blood vessel.

[0014]

[0014] It is a further advantage of the present disclosure to reduce the incidence of free flap failure and serious adverse events due to insufficient blood flow in the free flap.

[0015] It is yet another advantage of the present disclosure to provide a system, device and / or method for early detection of insufficient blood flow or circulation in a free flap.

[0016]

[0016] Additional features and advantages of the disclosed vascular monitoring system, device, and method will be described in and apparent from the following detailed description and drawings. The features and advantages described herein are not all-inclusive, and many additional features and advantages will become apparent to those skilled in the art, particularly in light of the drawings and description. Moreover, any particular embodiment need not possess all of the advantages enumerated herein. Furthermore, it should be noted that the terminology used herein has been selected primarily for purposes of readability and description, and not to limit the scope of the inventive subject matter. [Brief explanation of the drawings]

[0017] [Figure 1A] 1 is a schematic diagram of a probe system and monitor according to an exemplary embodiment of the present disclosure. [Figure 1B] 1 is a perspective view of a probe system and a monitor according to an exemplary embodiment of the present disclosure; [Figure 2] 1 is a perspective view of a monitor according to an exemplary embodiment of the present invention; [Figure 3] 1A-1D are various views of a monitor according to an exemplary embodiment of the present invention; [Figure 4] FIG. 2 is a schematic diagram of the internal components of a monitor according to an exemplary embodiment of the present invention. [Figure 5] 1 is a schematic diagram of an exemplary monitoring system according to an exemplary embodiment of the present disclosure. [Figure 6] FIG. 10 is a schematic diagram of a user interface displaying a monitor application on a user device according to an exemplary embodiment of the present disclosure. [Figure 7A] FIG. 1 is a partial perspective view of a vascular coupler including a transducer positioned around a patient's blood vessel according to an exemplary embodiment of the present disclosure. [Figure 7B] FIG. 1 is a partial perspective view of a transducer and lead wires positioned around a patient's blood vessel according to an exemplary embodiment of the present disclosure. [Figure 7C] 1 illustrates a partial cross-sectional view of a fastener and transducer of a vascular coupler according to an exemplary embodiment of the present disclosure. [Figure 7D] FIG. 1 is a perspective view of a vascular coupler including a transducer and lead wires according to an exemplary embodiment of the present disclosure. [Figure 8] 1 is a schematic diagram of an exemplary pulse wave transmitted and received by a monitor in accordance with an exemplary embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0018]

[0029] As described above, vascular monitoring systems, devices, and methods are provided to improve the accessibility, detectability, and / or reliability of detecting blood flow to confirm vascular patency at an anastomosis site. While free flap surgery has a history of success, the highly undesirable outcome of flap failure remains a possibility. One of the primary causes of flap failure is a lack of blood supply to the flap tissue after the free flap is reattached at the recipient site. Common causes of valve circulation include vascular blockage, bleeding, or infection. Lack of sufficient blood supply to the flap tissue results in tissue necrosis. However, the vascular monitoring systems, devices, and methods disclosed herein advantageously enable early detection of insufficient blood flow or circulation in a free flap, thereby salvaging or saving the free flap before tissue necrosis occurs.

[0019]

[0030] The above-described vascular monitoring systems, devices, and methods may be used to monitor blood flow at anastomotic sites to confirm vascular patency in surgical procedures, such as microvascular reconstruction with free flap transfer. The above-described systems, devices, and methods may be used in a variety of settings, such as hospital operating rooms or postanesthesia care units, to detect blood flow and confirm vascular patency (either on-site or remotely) both intraoperatively and postoperatively. Free flap transfer may also be used to reconstruct body parts during cancer and injury surgery using the patient's own tissue. Examples include breast reconstruction, tongue reconstruction, jaw and cheek reconstruction, and hand and foot reconstruction after traumatic injury. Typically, microvascular anastomosis is a critical point in surgery that determines the success of the flap. By providing monitoring capabilities for blood flow at the anastomosis site and increasing access to these monitoring capabilities (e.g., remote access via a monitoring application on a user device such as a smartphone), the systems, devices, and methods disclosed herein enable early detection of low or insufficient blood flow within the valve tissue, allowing medical personnel (e.g., surgeons) to take corrective action before necrosis begins to progress and render the free flap unusable.

[0020] Multi-configuration probe and monitor connections

[0031] FIG. 1A shows a schematic diagram of flow monitor system 100A, and FIG. 1B shows a perspective view of flow monitor system 100B (both of which may be generally referred to as flow monitor system 100). Flow monitor system 100 may include multi-configuration probe systems 102a and 102b attached to a monitor 150 via external leads 110a and 110b. For example, probe system 102a may be attached to "Channel A" of monitor 150 via external lead 110a, while probe system 102b may be attached to "Channel B" of monitor 150 via external lead 110b. Specifically, monitor 150 may provide monitoring of at least two anastomosis sites by having at least two Doppler probe inputs or connector ports (shown in FIG. 2) allowing user-selectable monitoring of either channel (e.g., "Channel A" or "Channel B"). Although the embodiment shown in Figures 1A and 1B uses leads 110a, 110b to connect the probe systems 102a, 102b to the monitor 150, it should be understood that a wireless system may be used in which the probes are configured to communicate with the monitor without using leads 110.

[0021]

[0032] A probe system (e.g., probe systems 102a and 102b, collectively referred to herein as probe system 102) includes a set of fasteners 104a, 104b that may form a vascular coupler joining two veins and / or arteries in an end-to-end anastomosis (see FIG. 7A). Probe system 102 may further include transducers 106a, 106b (see FIGS. 7A, 7B, 7C, and 7D) connected to at least one of fasteners 104a, 104b, respectively. For example, a ring may include a probe holder with a press-fit Doppler probe or transducer 106. In one example, a set or pair of fasteners (e.g., set of fasteners 104a, collectively referred to herein as fasteners 104) may include a pair of high-density polyethylene ("HDPE") rings with stainless steel pins (see FIGS. 7C and 7D). The pair of rings forms a permanent implant within the patient.

[0022]

[0033] A set or pair of fasteners 104 or rings may be sized to fit similarly sized arteries or veins. For example, the fasteners 104 or rings may have an inner diameter of 1.0 mm to 4.0 mm. In one embodiment, the inner diameter of the fasteners 104 may be provided in 0.5 mm increments. It should be understood that the fasteners 104 or rings may be sized and shaped to accommodate veins and arteries commonly encountered in microsurgical and revascularization procedures, and are adapted for end-to-end anastomosis of such veins and arteries in the peripheral vasculature.

[0023]

[0034] A vascular coupler formed from one or a pair of fasteners 104 may advantageously reduce anastomosis and valve ischemia time and provide intimal-to-intima contact without intraluminal foreign material (e.g., suture material), which also advantageously reduces the incidence of thrombosis. Furthermore, a vascular coupler may advantageously be capable of stenting an anastomosed vessel and may be used to correct vessel size discrepancies. For example, a pair of fasteners 104 may be used to connect veins or arteries of different sizes. Because the fasteners also provide intimal-to-intima contact without intraluminal foreign material, they advantageously improve patency rates compared to hand suturing.

[0024]

[0035] The vascular coupler formed by the pair of fasteners 104 is configured to form an end-to-end anastomosis of a blood vessel (e.g., a vein or artery) while holding and maintaining the position of transducer(s) 106 or other sensing device(s). The sensing device(s) can then be used to monitor or assess parameters related to the recovery and success of the surgical procedure, such as blood flow at the anastomosis site to confirm vascular patency. As described in more detail below, the sensing device(s) or transducer(s) 106 enable a medical professional (e.g., a surgeon) to monitor and analyze blood flow and / or blood flow velocity to determine the success of the procedure and / or to confirm vascular patency. Blood flow within the blood vessel can be monitored, and one or more audio samples of the blood flow may be recorded and stored in a database. Storing multiple recordings of blood flow audio samples at different times in a database allows a medical professional (e.g., a surgeon) to make comparisons between the recordings. The systems and methods disclosed herein advantageously allow for the recording and evaluation of blood flow data over time to analyze surgical success and patient characteristics (e.g., blood flow and blood flow velocity). Because anastomosis failure tends to occur fairly rapidly, the ability to continuously and reliably monitor and compare blood flow can be used to generate and transmit a signal associated with the detection of a failure event, allowing medical personnel (e.g., surgeons) to take corrective action before necrosis begins to progress and the free flap becomes unusable. Furthermore, as described in further detail below, the remote monitoring capabilities of the disclosed systems, devices, and methods advantageously provide remote access so that medical personnel (e.g., surgeons) can detect failure events regardless of their location (e.g., remotely) and without degrading audio quality.

[0025]

[0036] Any transducers 106a, 106b suitable for an ultrasound Doppler monitor may be used. In an exemplary embodiment, the Doppler probe or transducer is made of an approved implantable material, such as HDPE or silicone. In another example, the transducers 106a, 106b include piezoelectric crystals. The transducers 106a, 106b (hereinafter collectively referred to as transducers 106) may be of any size that fits the dimensions of a corresponding transducer receptacle (see FIG. 7C) used in the fastener of the vascular coupler. For example, a circular transducer 106 is suitable for being received by a receptacle whose inner surface has a circular shape. The transducer 106 may be a circular piezoelectric crystal measuring approximately 0.5 mm to approximately 1 mm in size. In one example, the Doppler probe or transducer 106 includes a tip having a circular piezoelectric crystal measuring approximately 0.5 mm to approximately 1 mm in size, a Teflon-coated coaxial wire, and a metal connector.

[0026]

[0037] The Doppler probe or transducer 106 may be a 20 MHz ultrasonic Doppler transducer that emits pulsed ultrasound signals when connected to the monitor 150 via the leads 110. For example, the monitor 150 may transmit and receive pulsed waves. In one embodiment (as shown in FIG. 8), eighteen 20 MHz pulses are enveloped and transmitted to the transducer 106 as transmit pulses. After receiving the transmit pulses, the pulses can excite the piezoelectric crystals so that the crystals vibrate and transmit ultrasound signals through the blood vessels. The enveloped transmit pulses may be repeated at a frequency of 78 kHz. After the transmit pulses are electronically stopped, the monitor 150 may receive or listen for return signals. For example, the monitor 150 may switch from transmitting pulses to receiving or listening for Doppler-shifted echoes (e.g., 6.4 μs) immediately after the transmit pulse (150 ns dead band). The Doppler-shifted echoes are transmitted back to the monitor. When the probe or transducer 106 detects blood flow, a varying audible signal is generated (e.g., from a Doppler-shifted echo), which may be processed and filtered by the monitor 150 before being made available to the user.

[0027]

[0038] As shown in FIG. 1A, the transducer 106 may include percutaneous leads (e.g., lead 108a of probe system 102a and lead 108b of probe system 102b, hereinafter collectively referred to as leads 108) attached to its surface. The percutaneous leads 108 have a proximal end (e.g., the end closest to the transducer 106) and a distal end. The percutaneous leads 108 preferably include two wires insulated by a common insulating material. The wires may be any wire suitable for monitoring 20 MHz signals from the transducer 106. In one embodiment, the insulating material preferably includes a biocompatible material, e.g., a Class VI medical-grade material. In one embodiment, the monitor 150 may have a 20 MHz transmit frequency including a continuous receive pulse wave transmission. The pulses may be repeated at a pulse repetition frequency of 156.25 KHz.

[0028]

[0039] At the proximal end, the percutaneous lead 108 may have one wire attached to each surface of the transducer 106. Any manufacturing method for attaching the two wires of the lead 108 to each surface of the transducer 106 may be used to create a strong conductive bond with the transducer 106 itself. Suitable methods include, but are not limited to, soldering, friction bonding, adhesive bonding, or attaching the leads during transducer manufacturing. In one embodiment, the bond strength between the transducer 106 and the two wires is preferably strong enough to separate the probe from the fastener socket by simply pulling on the lead itself. After use, the transducer may be left inside the body within the socket, or it may be removed by applying sufficient force to the percutaneous lead 108, for example, by pulling the transducer 106 from the socket and then pulling the leads 108 through the skin to the body surface. In one embodiment, the strength of the bond between the transducer 106 and the percutaneous lead 108 is greater than the force required to remove the transducer 106 from the patient by applying a mechanical force to the percutaneous lead 108 .

[0029]

[0040] The distal end of the percutaneous lead 108 may be disposed within an optional coupling pad (not pictured) that is placed against human skin. In one example, the coupling pad may be constructed of a medical-grade material suitable for contact with human skin, e.g., USP Grade V or VI material. Various alternative methods for attaching the lead to the skin may be used, including, for example, the use of patches and sutures. The coupling pad or alternative method may be attached to the skin in such a way that the force required to remove the pad or alternative method from the skin must be greater than the force required to separate the percutaneous lead 108 from the external leads 110a, 110b (collectively referred to hereinafter as the external leads 110). In a preferred embodiment, the force required to disconnect the percutaneous lead 108 from the external leads 110 should be less than the force required to remove the coupling pad or alternative attachment method (e.g., patch, suture, etc.) from the skin.

[0030]

[0041] 1A, the distal end of the percutaneous lead 108 may be fitted with connectors 120a, 120b (hereinafter collectively referred to as connectors 120) that can further connect the lead 108 to the proximal end of an external lead 110. The external lead 110 may be constructed of any wire suitable for use in carrying signals and insulated with a material suitable for skin contact. Preferably, the lead is configured to carry a 20 MHz signal.

[0031]

[0042] The connector 120 is preferably a medical-grade electrical connector. In an exemplary embodiment, the connector 120 is a non-locking connector. In another example, the connector 120 is an electrical medical-grade connector. A non-locking connector is beneficial in reducing the probability of accidental removal of the transducer from the anastomosis site. That is, if the external lead 110 is accidentally pulled, the non-locking connector 120 allows the external lead 110 to detach from the percutaneous lead 108 without disturbing the transducer 106. The bond pad or alternative attachment device can also help prevent disturbance of the transducer 106.

[0032]

[0043] The distal ends of external leads 110 are connected to monitor 150. The distal ends of external leads 110 may be connected in any suitable manner. In an exemplary embodiment, leads 110 are connected using connectors 130, which may be of the same type as connectors 120 (e.g., connector 130a for external lead 110a and connector 130b for external lead 110b). Connectors 120 and 130 may be metal or may have plastic housings.

[0033]

[0044] 1A, both inputs or channels are utilized and connected to respective Doppler probes. Additionally, although the preferred multi-configuration probe system uses leads 108, 110 to connect the probes to the monitor 150, a wireless system may also be used in which the probes are configured to communicate with the monitor 150 without the use of leads 108, 110.

[0034]

[0045] FIG. 1B shows a perspective view of a flow monitor system 100B with a multi-configuration probe system 102a attached to a monitor 150 via external leads 110a. The embodiment shown in FIG. 1B shows the probe system 102a attached to a single channel (e.g., "Channel A") of the monitor 150. It should be understood that more than two channels may be used. For example, the monitor 150 may be capable of monitoring more than two channels.

[0035] Monitor housing, structure and internal components

[0046] FIG. 2 shows an isometric view of an exemplary embodiment of monitor 150, and FIG. 3 shows various other views of monitor 150. Monitor 150 includes a housing 202 and a display or user interface 210, such as a color LCD touchscreen. Additionally, as shown in FIG. 2, monitor 150 includes a speaker 214 and a handle 216. Housing 202 and handle 216 may be made of injection-molded plastic (e.g., PC-ABS). Monitor 150 may further include various controls associated with display 210 and / or speaker 214, such as a volume control 220 (e.g., a volume control button or membrane switch), a mute control 222 (e.g., a mute button or membrane switch), and channel selection controls 224a and 224b (e.g., "Channel A" and "Channel B" channel selection buttons or membrane switches). The channel selection controls are associated with connector ports 226a and 226b that receive external leads 110. In one embodiment, monitor 150 may be approximately 6.17 inches D x 8.18 inches W x 3.20 inches H and may weigh approximately 1.84 pounds (0.83 kg). Additionally, as shown in FIG. 3, monitor 150 may include an AC power jack 230, feet 240a-240d, and a power control 250 (e.g., a power button or membrane switch). Additionally, monitor 150 may have wireless capabilities for remote access to previously recorded audio and / or blood flow data, as described in more detail in connection with FIG. 5.

[0036]

[0047] 4 is a schematic diagram illustrating various internal components and modules of flow monitor 150. Monitor 150 may include a power supply 302, a user interface or display 304, a touchscreen 306, a touchscreen controller 308, a processor 310, memory 312, communication modules (e.g., cellular communication module 316a and WiFi communication module 316b), a debug module 318, flash memory such as an Ultra Secure Digital High Capacity ("uSDHC") flash memory card, a boot loader 330, test points 334 for each channel (e.g., "Channel A" and "Channel B"), an analog front end ("AFE") 340, a filter module 342, an amplifier ("AMP") 350, speakers 314a and 314b (hereinafter collectively referred to as speakers 314), a battery 360, and a battery charge gauge 370.

[0037]

[0048] The processor 310 may communicate with the touchscreen 306 via a serial peripheral interface (“SPI”). The touchscreen 306 may be a resistive touchscreen associated with the display 304, such as a liquid crystal display. Some of the buttons shown in FIG. 2 (e.g., volume control 220, mute control 222, and channel selection controls 224a and 224b) may instead be displayed as graphical depictions on the displays 210, 304 that are selectable by touch using the touchscreen 306. The memory 312 may be DDR2 SDRAM and may temporarily store audio files before being transmitted to a remote server or database by one or more of the communication modules. The communication modules (e.g., cellular phone module 316a and WiFi module 316b) may communicate with the processor 310 via UART, USB, SPI, or other acceptable interfaces to send and receive data from a remote server or database. Similarly, the debug module 318 and the boot loader 330 may also communicate with the processor 310 via an interface (e.g., SPI). In one embodiment, the debug module 318 and boot loader 330 may be utilized for manufacturing testing, diagnostics, and repair. The communications module allows the monitor 150 to provide remote monitoring to medical personnel (e.g., surgeons), as described in more detail below. However, in the field, medical personnel (e.g., nurses and surgeons) can hear the resulting audio, which is amplified by the AMP 350 and then transmitted to the speakers 314a, 314b.

[0038] Signal generation / detection and audio / visual output

[0049] The monitor 150 generates a signal that is transmitted to the transducer 106 (e.g., the transducer 106 or probe emits a pulsed ultrasound signal) and transmitted through the vascular site. The transducer 106 then detects the signal transmitted through the blood vessel and transmits the detected signal back to the monitor 150, which converts the signal into a form that can be read by a user. When the probe detects flow, an audible signal of varying loudness is generated. For example, the signal may be converted into sound, a visual display, or both.

[0039]

[0050] The frequency (i.e., pitch) of the signal is proportional to the blood flow within the vessel. A unique tone pattern is generated, which indicates the blood flow pattern in terms of blood flow versus time. The tone pattern provides the surgeon with a qualitative indication of blood flow. The tone volume can be adjusted using the monitor's controls. The monitor's transmitter periodically drives an ultrasonic crystal at the tip of the probe. The crystal emits ultrasound waves that pass in a fairly narrow beam through the tissue just below the probe tip. The ultrasound waves are then reflected back toward the probe when they encounter a boundary between tissues of different densities. During periods when the unit is not transmitting, the probe passes all received reflected signals to a receiving circuit. This circuit amplifies the returning echoes, compares their frequency with the frequency of the transmitted signal, and converts the frequency difference into an audible tone.

[0040]

[0051] The Doppler probe and monitor 150 may be configured to detect blood flow at the anastomosis site and to verify vascular patency at the anastomosis site during and after surgery. For example, blood flow may be detected for up to about seven days post-surgery. Any monitor and probe combination capable of detecting audio output frequencies and blood flow velocities may be used. Preferably, the combination is capable of detecting audio output frequencies in the range of about 80 to about 3000 Hz and blood flow velocities in the range of 0.5 cm / sec to about 45 cm / sec.

[0041]

[0052] In a preferred embodiment, the monitor 150 displays a visual numeric value representing the frequency shift of the Doppler signal. The use of numeric values ​​allows the surgeon to store and trend the values ​​over time to detect and analyze patterns. Optionally, these numeric values ​​can also be downloaded to computer software for further analysis. In another preferred embodiment, the monitor 150 allows for monitoring of at least two anastomosis sites. In this embodiment, the monitor 150 has one or more Doppler probe inputs (e.g., "Channel A" and "Channel B"), allowing user-selectable monitoring of either channel.

[0042]

[0053] Monitor 150 is a pulsed Doppler ultrasound system designed for the detection of blood flow within blood vessels. When used in combination with probe system 102, monitor 150 can detect blood flow at the anastomosis site and confirm vascular patency during and after surgery. In one embodiment, blood flow may be detected post-operatively for several days (e.g., seven days) after surgery, if desired. In one embodiment, monitor 150 connects to a probe or transducer, such as a 20 MHz ultrasound Doppler probe or transducer 106, which emits a pulsed ultrasound signal, when connected to monitor 150 via leads 110. When probe or transducer 106 detects flow, a varying audible signal is generated. The audible signal may be displayed or emitted from monitor 150, as described in more detail below.

[0043]

[0054] As shown in FIG. 2 , display or user interface 210 provides a qualitative visual indication 212 of blood flow. In one embodiment, visual indication 212 may include various bars, each representing a frequency range or blood flow velocity threshold. For example, visual indication 212 of monitor 150 may be capable of indicating a blood flow velocity as low as 0.5 cm / sec or 0.75 cm / sec, and may be capable of indicating a blood flow velocity as high as 45 cm / sec. Monitor 150 may also emit an audible indication of blood flow via speaker 214. Before displaying the visual indication and / or emitting the audible indication, monitor 150 may filter the signal to remove noise. For example, monitor 150 may digitally filter the audio signal returned from probe or transducer 106 to reduce or remove noise.

[0044]

[0055] In another example, monitor 150 may display visual numerical values ​​representing blood flow or blood flow velocity (e.g., frequency shifts in the Doppler signal). Through the use of qualitative visual indications 212 or numerical values, a medical professional (e.g., a surgeon) may consider additional indications of blood flow (other than audio signals) to analyze post-operative vascular patency. Optionally, these numerical and / or visual indications may also be stored in a database (described in more detail below with reference to FIGS. 5 and 6) for further analysis.

[0045]

[0056] The visual display 212 displayed on the user interface 210 (or on the user device 402, described in more detail below) advantageously provides a secondary indicator of blood flow so that medical personnel can monitor and analyze a patient's blood flow in a noisy environment. For example, an operating room may have other sources of ambient noise from other medical instruments, other medical personnel, etc., and the visual display 212 may be monitored regardless of the amount of ambient noise. Conversely, an audible display may be difficult to analyze and distinguish from other sources of interference or noise.

[0046]

[0057] Referring again to FIG. 4 , the analog front end 340 receives signals or pulses from the processor 310. For example, the AFE 340 can receive 1 microsecond and 0.8 microsecond 78 KHz pulses from the processor 310, which are sent to the Doppler probe or transducer 106. The AFE 340 then receives a feedback signal (e.g., a phase shift) from the transducer 106, which is converted to an audio signal and sent to the filter 342 and / or the AMP 350. The audio signal represents the phase or Doppler shift that is detected by the monitor 150 and converted to audio. For example, ultrasound energy bounces off red blood cells in the blood vessels at the anastomosis site, causing a phase shift when the signal is emitted from the transducer 106. This phase shift is detected and converted to audio. Specifically, a signal proportional to the Doppler shift frequency and, in turn, blood velocity.

[0047] Digital Signal Filtering

[0058] In some cases, especially with low blood flow rates, the audio samples may be indistinguishable or difficult to distinguish from background noise. Furthermore, low blood flow rates may require the medical professional (e.g., surgeon) to turn up the volume on the monitor's speaker, which can be distracting or annoying when there is little background noise. Specifically, medical professionals (e.g., surgeons) determine vessel patency by a clear voice or audio signal, which is often difficult to detect when drowned out by the "hiss" of background noise from the speaker 214, 314. By digitally filtering the signal, the audio samples are clearly separated and isolated from the background noise so that they can be easily identified and reviewed by the medical professional without the annoying "buzz" or "hiss" of background noise emanating from the speaker.

[0048]

[0059] The audio signal may be digitally filtered to control background noise levels. For example, the filter module 342 may shape the audio signal via the filter module 342, which may utilize low-bandpass and high-bandpass digital filtering. In another embodiment, the filter module 342 may perform a fast Fourier transform (FFT) of the signal to split the audio signal into multiple frequency components that are digitally filtered. The digital filtering may include applying band-pass (low and high) filters and signal boosts (e.g., a 236 Hz boost).

[0049]

[0060] Furthermore, audio from low blood flow velocities is typically difficult to distinguish from the speaker's low-frequency rolloff. To improve audio quality, the signal can be boosted (e.g., a 236 Hz boost) before waveform shaping to raise the low-end frequencies above the speaker's low-frequency rolloff. The digital filtering described herein advantageously improves noise rejection while blood flow is detected within a specific velocity range, while the monitor's ability to generate an audible signal remains unchanged. Advantageously, digital filtering allows medical personnel to easily detect faint low signals associated with low blood flow velocities. Without digital filtering, the audio signal may be lost or drowned out in the background noise emanating from the speaker 214, 314.

[0050] Remote Monitor

[0061] FIG. 5 illustrates an exemplary system 400 including a monitor 150 in communication with a management station 470, a cloud computing infrastructure 480, and one or more of user devices 402. The management station 470 may be used to apply settings and permissions to various mobile or user devices 402 in communication with the cloud computing infrastructure 480. The monitor 150 may include each of the components illustrated in FIGS. 2-4. As illustrated in FIG. 5, several monitor components (some of which were previously described in FIG. 4) are illustrated, such as a processor 410, a transceiver such as a universal asynchronous receiver-transmitter (“UART”) 412, a complex programmable logic device (“CPLD”) 420, a boot loader 430, a connectivity module 440, memory devices 450a and 450b (collectively referred to as memory devices 450), and an input / output (I / O) device 460.

[0051]

[0062] The monitor 150 may be in communication with a cloud computing infrastructure 480 (e.g., Amazon Web Services (“AWS”)), which may include a backend server 482 (e.g., a backend AWS Elastic Compute Cloud (“EC2”) server), an audio server 484, a database search tool (e.g., Mongo DB), and a database 488 (e.g., Amazon Simple Storage Service (“S3”)). Communications between the monitor 150 and the cloud computing infrastructure 480 via a communications module 440, such as a WiFi module, may be encrypted. For example, communications encryption at 405 may include over-the-air (“OTA”) encryption using Wi-Fi Protected Access (“WPA”) or Wi-Fi Protected Access II (“WPA2”). Additionally, communications between monitor 150 and cloud computing infrastructure 480 may utilize communications protocols at 407 such as the Transport Layer Security (“TLS”) protocol to provide secure communications over the Internet for data transfer, such as when transferring patient audio files 490 to a remote server (e.g., backend server 482 or audio server 484) or database 488.

[0052]

[0063] When communicating, the back-end server 482 can request device status or query the latest audio sample from the monitor 150 via arrow 425. For example, the back-end server 482 may request device status such as the transducer ID, which channel of the monitor is active, or whether the monitor is actively listening (e.g., recording audio samples). Additionally, the back-end server 482 may query the monitor 150 for the latest audio sample. For example, the device status and / or audio sample of the monitor 150 may be communicated between the connection module 440 and the back-end server 482. Additionally, the back-end server 482 may obtain audio information, such as audio file 490, from the monitor 150 via the connection module 440 via arrow 435. Both the device status information and the audio information may be passed to the database search tool 486 via arrow 445. The monitor 150 may also upload audio information, such as audio file 490, to the audio server 484 via arrow 455. The audio server 484 may store data such as audio information in a database search tool 486 at arrow 465. Additionally, the audio server 484 may store audio information such as audio files 490 in a database 488 at arrow 475.

[0053]

[0064] A healthcare professional, such as a nurse, may communicate with the cloud computing infrastructure 480 at arrow 485 and manage data therein. In one embodiment, a probe or transducer ID or model number, audio identification information, patient identification information, hospital information, or healthcare professional (e.g., surgeon) information may be associated with a particular patient, audio identifier, probe or transducer 106, and / or healthcare professional (e.g., surgeon) so that a surgeon can retrieve only the specific audio files to which the surgeon has been granted access via his or her user device 402. Additionally, communication between the management station 470 and the cloud computing infrastructure 480 may utilize a communication protocol such as TLS. Another healthcare professional, such as a surgeon, or a privileged user may request audio at arrow 495 and play audio at arrow 497 by communicating with the cloud computing infrastructure 480. Specifically, the user device 402 may communicate with the back-end server 482 and database 488 to play the audio file 490.

[0054]

[0065] As used herein, a physical processor or processor 410 refers to a device capable of executing instructions that encode arithmetic, logical, and / or I / O operations. In one exemplary embodiment, the processor may follow a von Neumann architecture model and may include an arithmetic logic unit (ALU), a control unit, and multiple registers. In further aspects, the processor may be a single-core processor, typically capable of executing one instruction at a time (or processing one instruction pipeline), or a multi-core processor, capable of executing multiple instructions simultaneously. In other aspects, the processor may be implemented as a single integrated circuit, two or more integrated circuits, or may be a component of a multi-chip module (e.g., individual microprocessor dies contained in a single integrated circuit package and thus sharing a single socket). A processor may also be referred to as a central processing unit (CPU). Furthermore, a processor may also be a microprocessor, a microcontroller, or a microcontroller unit (MCU).

[0055]

[0066] As described herein, memory device 450 refers to a volatile or non-volatile memory device, such as a random access memory (RAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), or other device capable of storing data. As described herein, I / O device 460 refers to a device capable of providing an interface between one or more processor pins and an external device capable of inputting and / or outputting binary data.

[0056]

[0067] The processors 410 may be interconnected using a variety of technologies ranging from point-to-point processor interconnects to system area networks such as Ethernet-based networks. Local connections within the monitor 150, including connections between the processors 410, the CPLDs 410, the connectivity modules 440, the memory devices 450, and the I / O devices 460, may be provided by one or more local buses of a suitable architecture, such as Peripheral Component Interconnect (PCI).

[0057] Remote monitoring application

[0068] In some situations, medical personnel (e.g., a surgeon) may not be on-site to review and analyze the audible indications emitted by monitor 150 and / or the qualitative visual indications 212 displayed by monitor 150. In such situations, the patient must wait for the surgeon to return to the hospital operating room or post-anesthesia care unit, or another practitioner or staff member may relay the information to the surgeon. For example, in some cases, the surgeon may attempt to listen to the audible indications (e.g., audio played by monitor 150) in real time over the telephone, which may result in signal degradation depending on cellular reception, cellular carriers, etc. The inconvenience of having to be on-site to review and analyze the patient's blood flow data typically results in reduced monitoring frequency.

[0058]

[0069] To improve accessibility and ease of patient monitoring, user device 402 may execute an application to remotely access audio files 490 stored in database 488. A medical professional (e.g., a nurse) may assign access credentials to specific medical professionals (e.g., surgeons) at administration station 470. Once access rights or privileges are granted, a user (e.g., a surgeon) using the monitoring application on user device 402 can search for and play audio files associated with a particular implanted Doppler probe or transducer 106. For example, while blood flow audio files for multiple patients from multiple different hospitals may be stored in database 488, "Surgeon_A" may be assigned access rights or privileges to listen to the audio files associated with "Doppler probe_A" implanted in "Patient_A." Similarly, "Surgeon_B" may be assigned access rights or privileges to listen to the audio files associated with "Doppler probe_B" implanted in "Patient_B" and "Doppler probe_C" implanted in "Patient_C."

[0059]

[0070] When accessing audio files on the user device 402, the medical professional (e.g., a surgeon) may request to hear the “current” blood flow audio file. For example, as shown in FIG. 6 , the medical professional (e.g., a surgeon) may select the graphical depiction of the “Request-Current” button 502 to hear a “current recording” of the blood flow at the anastomosis site. In one example, selecting the “Request-Current” button 502 may initiate a recording, which may not be a real-time audio signal of the blood flow but may instead be delayed for a short period of time (e.g., 10 seconds, 15 seconds, 20 seconds, etc.). For example, by selecting button 502, a 15-second recording of the patient's blood flow audio signal may be recorded and uploaded to the database 488, which may then be retrieved and played by the user device 402 to provide an audible indication of the blood flow through the user device 402's speaker. The application may also allow the medical professional (e.g., a surgeon) to play, listen to, and review past audio recordings for that patient. For example, by selecting either the graphical depiction of the "Past Recording_1" button 504, the "Past Recording_2" button 506, or the "Past Recording_3" button 508, a medical professional (e.g., a surgeon) can listen to past recordings of audio signals of the patient's blood flow. By doing so, the surgeon can compare the audio signals and determine whether the patient's blood flow is improving, worsening, or remaining about the same.

[0060]

[0071] Recording may be performed for a duration ranging from 5 seconds to 20 seconds, although it should be understood that other durations may be used. In another embodiment, the duration may be selectable by a medical professional (e.g., a surgeon) through a mobile application.

[0061]

[0072] In another example, the application may provide a qualitative visual display 512 of blood flow, similar to the qualitative visual display 212 shown in Figure 2. In one example, the visual display 512 may include various bars, each representing a frequency range or blood flow velocity threshold. Similar to the qualitative visual display 212 of the monitor 150 described above, the qualitative visual display 512 of the application on the user device 402 may be able to indicate blood flow velocities as low as 0.5 cm / sec or 0.75 cm / sec and as high as 45 cm / sec.

[0062]

[0073] For example, various aspects of blood flow within a blood vessel can be monitored and recorded. Access to several past records allows a medical professional (e.g., a surgeon) to objectively compare a current record with past records. For example, a qualitative visual display 512 associated with a record can provide a baseline value against which other records can be compared.

[0063]

[0074] The application may display the audio ID 520, probe ID 530, and other recording information 540 so that the medical professional can determine which patient and / or probe the audio file corresponds to. Additionally, the recording information 540 may indicate the date and time of the recording, etc.

[0064]

[0075] It should be understood that the user device 402 may be a smartphone, tablet, laptop, computer, smartwatch, or any other suitable device.

[0065]

[0076] Aspects of the subject matter described herein may be useful alone or in combination with one or more other aspects described herein. In a first exemplary aspect of the present disclosure, a Doppler blood flow monitor device includes a signal generation module, a signal receiving module, a signal filter module, a signal conversion module, at least one speaker, and a user interface. The signal generation module is configured to transmit a signal to a probe disposed in a probe receptacle of a vascular coupler disposed around a patient's blood vessel. The signal receiving module is configured to receive a return signal from the probe. The signal filter module is configured to filter the return signal. The signal conversion module is configured to convert the filtered signal into an audible indication and a visual indication corresponding to a characteristic of blood flow in the patient's blood vessel. The at least one speaker is configured to emit a first audible indication. Additionally, the user interface is configured to display a visual indication.

[0066]

[0077] According to another exemplary aspect of the present disclosure, which may be used in combination with any one or more of the preceding aspects, the signal transmitted by the signal-generating module is a pulsed ultrasound signal.

[0067]

[0078] According to another exemplary aspect of the present disclosure, which may be used in combination with any one or more of the preceding aspects, the signal transmitted by the signal generating module is a pulsed wave Doppler signal.

[0068]

[0079] According to another example aspect of the present disclosure that may be used in combination with any one or more of the preceding aspects, filtering the feedback signal includes at least one of applying a low band-pass filter to the feedback signal, applying a high band-pass filter to the feedback signal, and applying a fast Fourier transform to the feedback signal.

[0069]

[0080] According to another exemplary aspect of the present disclosure that may be used in combination with any one or more of the preceding aspects, filtering the feedback signal includes applying a frequency adjustment to the feedback signal, the frequency adjustment being applied to the feedback signal prior to shaping the feedback signal.

[0070]

[0081] According to another exemplary aspect of the present disclosure that may be used in combination with any one or more of the preceding aspects, the frequency adjustment is a frequency boost of 150 Hz to 300 Hz.

[0071]

[0082] According to another exemplary embodiment of the present disclosure, which may be used in combination with any one or more of the preceding embodiments, the frequency boost is between 230 Hz and 240 Hz.

[0072]

[0083] Aspects of the subject matter described herein may be useful alone or in combination with one or more other aspects described herein. In a second exemplary embodiment of the present disclosure, a Doppler blood flow monitoring system includes a vascular coupler, a transducer, and a monitor. The vascular coupler is positioned around a patient's blood vessel. The transducer is attached to the vascular coupler. The monitor is configured to generate a signal to transmit to the transducer, and the transducer is configured to emit an ultrasound signal based on the signal generated by the monitor. Additionally, the ultrasound signal is transmitted through the patient's blood vessel. The monitor is further configured to receive a return signal from the transducer and convert the return signal into a first indication and a second indication corresponding to a characteristic of the blood flow in the patient's blood vessel.

[0073]

[0084] According to another exemplary aspect of the present disclosure, which may be used in combination with any one or more of the preceding aspects, the first indication is an audible indication.

[0074]

[0085] According to another exemplary aspect of the present disclosure, which may be used in combination with any one or more of the preceding aspects, the second indication is a visual indication.

[0075]

[0086] According to another exemplary aspect of the present disclosure that may be used in combination with any one or more of the preceding aspects, the vascular coupler is a first vascular coupler, and the transducer is a first transducer. Further, the first vascular coupler and the first transducer are associated with a first channel of a monitor. In one embodiment, the system further includes a second vascular coupler and a second transducer disposed around a different blood vessel of the patient. The second vascular coupler and the second transducer are associated with a second channel of the monitor. Further, the monitor is further configured to generate a different signal to transmit to the second transducer, receive a different return signal from the second transducer, and convert the different return signals into primary and secondary representations corresponding to characteristics of the blown flow in the different blood vessels of the patient.

[0076]

[0087] According to another exemplary aspect of the present disclosure, which may be used in combination with any one or more of the preceding aspects, the primary indication is an audible indication.

[0077]

[0088] According to another exemplary aspect of the present disclosure, which may be used in combination with any one or more of the preceding aspects, the secondary indication is a visual indication.

[0078]

[0089] According to another exemplary aspect of the present disclosure, which may be used in combination with any one or more of the preceding aspects, the signal emitted from the transducer is a pulsed ultrasound signal.

[0079]

[0090] According to another exemplary aspect of the present disclosure, which may be used in combination with any one or more of the preceding aspects, the signal generated by the monitor is a pulsed ultrasound signal.

[0080]

[0091] According to another exemplary aspect of the present disclosure, which may be used in combination with any one or more of the preceding aspects, the signal emitted from the transducer is a pulsed wave Doppler signal.

[0081]

[0092] According to another exemplary aspect of the present disclosure, which may be used in combination with any one or more of the preceding aspects, the signal generated by the monitor is a pulsed wave Doppler signal.

[0082]

[0093] According to another exemplary aspect of the present disclosure, which may be used in combination with any one or more of the preceding aspects, the transducer is removably held within the vascular coupler.

[0083]

[0094] According to another exemplary aspect of the present disclosure, which may be used in combination with any one or more of the preceding aspects, the transducer is removably held within the vascular coupler by at least one of a friction fit, a mechanical coupler, and an adhesive.

[0084]

[0095] According to another exemplary aspect of the present disclosure, which may be used in combination with any one or more of the preceding aspects, the vascular coupler is configured to allow the transducer to be subsequently removed from the receptacle of the vascular coupler.

[0085]

[0096] According to another example aspect of the present disclosure that may be used in combination with any one or more of the preceding aspects, the monitor is further configured to filter the feedback signal before converting the feedback signal into at least one of the first representation and the second representation.

[0086]

[0097] According to another example aspect of the present disclosure that may be used in combination with any one or more of the preceding aspects, filtering the feedback signal includes at least one of applying a low band-pass filter to the feedback signal, applying a high band-pass filter to the feedback signal, and applying a fast Fourier transform to the feedback signal.

[0087]

[0098] According to another exemplary aspect of the present disclosure that may be used in combination with any one or more of the preceding aspects, filtering the feedback signal includes applying a frequency adjustment to the signal, the frequency adjustment being applied to the feedback signal prior to waveform shaping of the feedback signal.

[0088]

[0099] According to another exemplary aspect of the present disclosure that may be used in combination with any one or more of the preceding aspects, the frequency adjustment is a frequency boost of 150 Hz to 300 Hz.

[0089]

[0100] According to another exemplary embodiment of the present disclosure, which may be used in combination with any one or more of the preceding embodiments, the frequency boost is between 230 Hz and 240 Hz.

[0090]

[0101] According to another exemplary aspect of the present disclosure, which may be used in combination with any one or more of the preceding aspects, the transducer includes a piezoelectric crystal.

[0091]

[0102] Aspects of the subject matter described herein may be useful alone or in combination with one or more other aspects described herein. In a third exemplary aspect of the present disclosure, a remote monitoring system includes a monitor and a remote database. The monitor is configured to generate a signal to transmit to a transducer disposed within a vascular coupler. The vascular coupler is disposed around a patient's blood vessel, and the transducer is configured to emit an ultrasound signal based on the signal generated by the monitor, the ultrasound signal being transmitted through the patient's blood vessel. The monitor is further configured to receive a return signal from the transducer and convert the return signal into a first representation and a second representation corresponding to a characteristic of the blown flow of the patient's blood vessel. The remote database is configured to receive one or more files associated with the first representation and store one or more files associated with the first representation, the one or more files being remotely accessible via a user device.

[0092]

[0103] According to another example aspect of the present disclosure that may be used in combination with any one or more of the preceding aspects, the monitor is further configured to filter the feedback signal before converting the feedback signal into at least one of the first representation and the second representation.

[0093]

[0104] According to another example aspect of the present disclosure that may be used in combination with any one or more of the preceding aspects, filtering the feedback signal includes at least one of applying a low band-pass filter to the feedback signal, applying a high band-pass filter to the feedback signal, and applying a fast Fourier transform to the feedback signal.

[0094]

[0105] According to another exemplary aspect of the present disclosure that may be used in combination with any one or more of the preceding aspects, filtering the feedback signal includes applying a frequency adjustment to the feedback signal, the frequency adjustment being applied to the feedback signal before waveform shaping of the feedback signal.

[0095]

[0106] According to another exemplary aspect of the present disclosure that may be used in combination with any one or more of the preceding aspects, the frequency adjustment is a frequency boost of 150 Hz to 300 Hz.

[0096]

[0107] According to another exemplary embodiment of the present disclosure, which may be used in combination with any one or more of the preceding embodiments, the frequency boost is between 230 Hz and 240 Hz.

[0097]

[0108] According to another exemplary aspect of the present disclosure, which may be used in combination with any one or more of the preceding aspects, the remote database is further configured to receive one or more files associated with the second representation and store the one or more files associated with the second representation, wherein the one or more files associated with the second representation are remotely accessible via the user device.

[0098]

[0109] The many features and advantages of the present disclosure are apparent from the written description, and thus, the appended claims are intended to cover all such features and advantages of the present disclosure. Moreover, since numerous modifications and changes will readily occur to those skilled in the art, the present disclosure is not limited to the exact construction and operation shown and described. Therefore, the described embodiments should be understood to be illustrative and not restrictive, and the present disclosure should not be limited to the details given herein, but should be defined by the following claims and their full scope of equivalents, whether now or in the future foreseeable or unforeseeable.

Claims

1. 1. A Doppler blood flow monitor device, comprising: a signal generating module configured to transmit a signal to a probe disposed in a probe receptacle of a vascular coupler that is disposed about a blood vessel of a patient; a signal receiving module configured to receive a return signal from the probe; a signal filter module configured to filter the feedback signal; a signal conversion module configured to convert the filtered signal into a first audible indication corresponding to a characteristic of blood flow within a blood vessel of the patient; a connection module configured to transfer the first audible indication to a remote database accessible via a user device, wherein an administration station is configured to grant the user device access to the first audible indication, such that the user device can request the Doppler blood flow monitor device to record and upload a second audible indication that is a current record of blood flow; and A Doppler blood flow monitor device comprising:

2. 10. The Doppler blood flow monitor device of claim 1, wherein the signal transmitted by the signal generating module is at least one of (i) a pulsed ultrasound signal or (ii) a pulsed wave Doppler signal.

3. 2. The Doppler blood flow monitor device of claim 1, wherein filtering the return signal includes at least one of: (i) applying a low bandpass filter to the return signal; (ii) applying a high bandpass filter to the return signal; (iii) applying a fast Fourier transform to the return signal; or (iv) applying a frequency adjustment to the return signal, wherein the frequency adjustment is applied to the return signal before shaping the return signal.

4. 4. The Doppler blood flow monitor device of claim 3, wherein the frequency adjustment is between 230 Hz and 240 Hz.

5. a vascular coupler for placement around a blood vessel of the patient; a transducer attached to the vascular coupler; The monitor and A Doppler blood flow monitoring system comprising: The monitor generating a signal to transmit to the transducer, the transducer configured to emit an ultrasound signal based on the signal generated by the monitor, the ultrasound signal being transmitted through a blood vessel of the patient; receiving a feedback signal from the transducer; converting the return signal into a first representation corresponding to a characteristic of blood flow within the patient's blood vessel; wirelessly transferring one or more files associated with the first indication via a connection module to a remote database accessible via a user device, wherein an administration station is configured to grant the user device access to the one or more files associated with the first indication, and wherein the user device can request the monitor to record and upload a second audible indication that is a current record of blood flow; A Doppler blood flow monitoring system configured to:

6. 6. The Doppler blood flow monitor system of claim 5, wherein the first display is a visual display including a plurality of bars each representing a blood flow velocity threshold, and the monitor is further configured to convert the return signal into a second display, the second display being an audible display.

7. the vascular coupler is a first vascular coupler, the transducer is a first transducer, and the first vascular coupler and the first transducer are associated with a first channel of the monitor; The Doppler blood flow monitoring system includes: a second vascular coupler for placement around a different blood vessel of the patient; a second transducer, wherein the second vascular coupler and the second transducer are associated with a second channel of the monitor; and Furthermore, the first vascular coupler and the first transducer are connected to a first input connector port of the monitor via a first external lead; the first input connector port is associated with the first channel; the second vascular coupler and the second transducer are connected to a second input connector port of the monitor via a second external lead; The second input connector port is associated with the second channel, and the monitor generating another signal to transmit to the second transducer; receiving a different return signal from the second transducer; converting the different return signals into primary and secondary representations corresponding to characteristics of blood flow within the different blood vessels of the patient; 6. The Doppler blood flow monitoring system of claim 5, further configured to:

8. 8. The Doppler blood flow monitoring system of claim 7, wherein said primary indication is an audible indication and said secondary indication is a visual indication.

9. 6. The Doppler blood flow monitor system of claim 5, wherein the signal emitted by the transducer is at least one of a pulsed ultrasound signal and a pulsed wave Doppler signal, and the signal generated by the monitor is at least one of a pulsed ultrasound signal and a pulsed wave Doppler signal.

10. 6. The Doppler blood flow monitoring system of claim 5, wherein the transducer is removably held within the vascular coupler.

11. 6. The Doppler blood flow monitoring system of claim 5, wherein the vascular coupler is configured to allow the transducer to be subsequently removed from a receptacle in the vascular coupler.

12. 6. The Doppler blood flow monitor system of claim 5, wherein the monitor is further configured to filter the return signal before converting the return signal to the first representation.

13. 13. The Doppler blood flow monitoring system of claim 12, wherein filtering the return signal includes applying a frequency adjustment to the signal, the frequency adjustment being applied to the return signal before shaping the return signal, the frequency adjustment being a frequency boost of 150 Hz to 300 Hz.

14. 6. The Doppler blood flow monitoring system of claim 5, wherein the transducer includes a piezoelectric crystal.

15. 1. A remote monitoring system comprising a monitor, the monitor comprising: generating a signal to transmit to a transducer disposed within the vascular coupler; the vascular coupler is positioned around a blood vessel of the patient; the transducer is configured to emit an ultrasonic signal based on the signal generated by the monitor; the ultrasound signal is transmitted through a blood vessel of the patient. and receiving a feedback signal from the transducer; converting the return signal into a first representation corresponding to a characteristic of blood flow within the patient's blood vessel; wirelessly transferring one or more files associated with the first indication to a remote database via a connectivity module, wherein a management station is configured to grant a user device access to the one or more files associated with the first indication, and wherein the user device can request the monitor to record and upload a second audible indication that is a current record of blood flow; and the remote database is configured to: receiving the one or more files associated with the first representation; storing the one or more files associated with the first representation, the one or more files being remotely accessible via the user device; A remote monitoring system configured to:

16. The remote monitoring system of claim 15 , wherein the monitor is further configured to filter the feedback signal before converting the feedback signal to the first representation.

17. 17. The remote monitoring system of claim 16, wherein filtering the feedback signal comprises at least one of applying a low bandpass filter to the feedback signal, applying a high bandpass filter to the feedback signal, and applying a fast Fourier transform to the feedback signal.

18. 16. The remote monitoring system of claim 15, wherein filtering the feedback signal includes applying a frequency adjustment to the signal, the frequency adjustment being applied to the feedback signal before shaping the feedback signal.

19. 20. The remote monitoring system of claim 18, wherein the frequency adjustment is a frequency boost of 150 Hz to 300 Hz.

20. 16. The remote monitoring system of claim 15, wherein the monitor is further configured to convert the feedback signal into a second indication, the second indication being an audible indication.

Images