Omnidirectional wireless energy transmission system for implantation / intervention type diagnosis and treatment equipment

Abstract

An omni-directional wireless energy transmission system for implanted / interventional diagnosis and treatment equipment comprises an omni-directional wireless energy transmitting subsystem which is arranged outside a body and is used for generating an alternating rotating magnetic field with constant intensity and a wireless energy receiving subsystem which wirelessly receives electric energy through electromagnetic induction, wherein the wireless energy receiving subsystem forwards received wireless energy to an internal circuit of the implanted / interventional diagnosis and treatment equipment. A three-dimensional energy transmitting coil and one-dimensional energy receiving coil coupling structure is adopted, a high-order LCC-S resonance compensation topological structure insensitive to load change is adopted, and it can be guaranteed that implantation / interventional diagnosis and treatment equipment can obtain sufficient and stable energy supply at any position and posture in a working space; and the applicability of the wireless energy transmission system is improved.

Description

Technical Field

[0001] The present invention relates to a technology in the field of wireless medical equipment, in particular to an omnidirectional wireless energy transmission system for implantable / interventional diagnosis and treatment equipment. Background Art

[0002] The existing wireless energy transmission system for implantable / interventional diagnosis and treatment equipment based on the magnetic coupling resonance principle usually adopts an electromagnetic coupling structure of a one-dimensional transmitting coil and a three-dimensional orthogonal receiving coil. The three-dimensional orthogonal receiving coil is located inside the implantable / interventional diagnosis and treatment equipment, and has a complex structure and is difficult to wind. At the same time, due to the narrow internal space of the implantable / interventional diagnosis and treatment equipment, the size and number of turns of the three-dimensional receiving coil are severely limited, resulting in a small coupling coefficient between the transmitting coil and the receiving coil, low energy transmission efficiency, and low receiving energy. It is difficult to meet the growing energy needs of implantable / interventional diagnosis and treatment equipment. Summary of the invention

[0003] In view of the shortcomings of the existing composite magnetic field technology that cannot ensure the consistency of magnetic field intensity in different directions and cannot achieve a truly three-dimensional omnidirectional uniform magnetic field, and the defect that the existing motor control technology cannot control the phase difference between the three-phase currents to meet the control requirements, the present invention proposes an omnidirectional wireless energy transmission system for implantable / interventional diagnostic and treatment equipment. The system adopts a three-dimensional energy transmitting coil and a single-dimensional energy receiving coil coupling structure, and adopts a high-order LCC-S resonant compensation topology structure that is insensitive to load changes. It can ensure that the implantable / interventional diagnostic and treatment equipment can obtain sufficient and stable energy supply at any position and posture in the working space, thereby improving the applicability of the wireless energy transmission system.

[0004] The present invention is achieved through the following technical solutions:

[0005] The present invention relates to an omnidirectional wireless energy transmission system for implantable / interventional diagnosis and treatment equipment, comprising: an omnidirectional wireless energy transmitting subsystem placed outside the body for generating an alternating rotating magnetic field with constant intensity and a wireless energy receiving subsystem for wirelessly receiving electrical energy through electromagnetic induction, wherein: the wireless energy receiving subsystem forwards the received wireless energy to the internal circuit of the implantable / interventional diagnosis and treatment equipment.

[0006] The omnidirectional wireless energy transmission subsystem includes: a phase-adjustable signal control unit, an LCC resonance compensation network and a three-dimensional energy transmission coil connected in sequence, wherein: the phase-adjustable signal control unit includes: a power supply module and a control circuit module, a drive circuit module and an inverter circuit module respectively connected thereto.

[0007] The wireless energy receiving subsystem includes: an energy receiving coil, a resonant compensation capacitor, a full-bridge rectifier circuit module and a voltage stabilizing circuit module connected in sequence, wherein: the resonant compensation capacitor and the energy receiving coil are connected in series to form a series resonant network; the full-bridge rectifier module converts the AC voltage sensed by the receiving coil into a DC voltage and outputs it to the voltage stabilizing circuit module, and the voltage stabilizing circuit module stabilizes the rectified voltage at the required value and outputs it to the internal circuit of the implantable / interventional diagnostic and treatment equipment.

[0008] The three-dimensional energy transmitting coil comprises: a pair of Helmholtz coils whose normal lines are arranged parallel to the axis direction of the cylindrical coil frame and two pairs of saddle coil pairs whose normal lines are perpendicular to the normal lines of the Helmholtz coils, wherein: the Helmholtz coil as the innermost coil is wound on the cylindrical coil frame to generate a magnetic field in the z direction, the first saddle coil pair is wound on the outer layer of the Helmholtz coil to generate a magnetic field in the y direction, and the second saddle coil pair is wound on the outer layer of the first saddle coil to generate a magnetic field in the x direction, and the three pairs of coils are orthogonally decoupled from each other and form a cylindrical structure. Technical Effects

[0009] The present invention uses a three-dimensional energy transmitting coil composed of a pair of Helmholtz coils and two pairs of saddle-shaped coils to increase the internal working space, facilitate human access and cover the abdominal examination area of ​​the human body, and facilitate the clinical use of implantable / interventional diagnostic and treatment equipment, such as capsule endoscopes, magnetically controlled capsule endoscopes, gastrointestinal micro-robots, etc. for disease diagnosis and treatment; by adjusting the phase difference of the control signal, the uniform three-dimensional omnidirectional magnetic field generated can cover all angles of the space, is simple and easy to implement, does not require additional coil current detection circuits, reduces system complexity, and enables implantable / interventional diagnostic and treatment equipment to maintain stable operation under different motion states. This method significantly improves the reliability and applicability of the wireless energy transmission system and meets the high requirements of implantable / interventional diagnostic and treatment equipment for energy supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the system of the present invention;

[0011] Figure 2 A schematic diagram of an inverter circuit control signal of an embodiment;

[0012] Figure 3 (a) and Figure 3 (b) is a schematic diagram of the structure of the three-dimensional energy transmitting coil;

[0013] Figure 4 (a) and Figure 4 (b) is the time-varying diagram of magnetic field intensity and the schematic diagram of omnidirectional rotating magnetic field;

[0014] Figure 5 It is a principle block diagram of the phase difference optimization control strategy of the embodiment. DETAILED DESCRIPTION

[0015] like Figure 1 As shown, this embodiment relates to an omnidirectional wireless energy transmission system for implantable / interventional diagnostic and treatment equipment, including: an omnidirectional wireless energy transmitting subsystem 1 placed outside the body for generating an alternating rotating magnetic field with a constant intensity and a wireless energy receiving subsystem 2 for wirelessly receiving electrical energy through electromagnetic induction, wherein: the wireless energy receiving subsystem 2 forwards the wireless energy to the internal circuit of the implantable / interventional diagnostic and treatment equipment.

[0016] The omnidirectional wireless energy transmitting subsystem 1 comprises: a phase-adjustable signal control unit, an LCC resonance compensation network 105 and a three-dimensional energy transmitting coil 106 connected in sequence, wherein: the signal control unit generates three pairs of six-channel PWM signals through internal programming, and outputs three pairs of square wave signals to the LCC resonance compensation network 105 through a driving circuit and an inverter circuit. The LCC resonance compensation network 105 converts the input three pairs of square wave signals into three-phase sinusoidal AC signals through first-order LC filtering and second-order LC resonance. The three-phase sinusoidal AC signals flow through the three-dimensional energy transmitting coil 106, thereby generating a three-dimensional alternating magnetic field.

[0017] In the three pairs of six-channel PWM signals: the first group of control signals is defined as zero phase, and the phase differences α and β between the second and third groups of signals and the first group of signals are determined by the phase difference optimization control strategy.

[0018] The phase-adjustable signal control unit includes: a power supply module 101 and a control circuit module 102, a drive circuit module 103 and an inverter circuit module 104 respectively connected thereto, wherein: the control circuit module 102 generates initial three pairs of six-way PWM signals with phase difference according to a phase difference optimization control strategy and outputs them to the drive circuit module 103; the drive circuit module 103 converts the initial three pairs of six-way PWM signals into control signals sufficient to drive the MOSFET in the inverter circuit module 104 to work normally; the inverter circuit module 104 generates a three-phase AC signal under the control of the three pairs of six-way control signals generated by the drive circuit module 103.

[0019] The phase difference optimization control strategy is: as well as Under the premise of , the phase differences α and β are calculated, where A and B are the decomposition coefficients of the synthetic magnetic field intensity H in three-dimensional space, and A and B satisfy: K x , K yz are the proportional relationship between the magnetic field strength generated by the Helmholtz coil 3, the saddle coil pair 4 and 5 and the current flowing into the coil, ω0 is the system operating angular frequency, I m is the amplitude of the current flowing through the transmitting coil.

[0020] like Figure 5 As shown, the phase difference optimization control strategy specifically includes:

[0021] Step 1) Select a suitable series compensation inductor Ls, construct an LCC resonance compensation network 105 , and connect the LCC resonance compensation network 105 to the inverter circuit module 104 and the three-dimensional energy transmitting coil 106 .

[0022] Step 2) Set the inverter circuit DC supply voltage U dc , where the theoretical emission current is only related to the DC supply voltage U dc is related to the series compensation inductance Ls, while the decomposition coefficients A and B of the synthetic magnetic field intensity H in three-dimensional space are only related to the theoretical emission current, thus: as well as The theoretical phase differences α and β of the control signals are calculated.

[0023] Step 3) Testing the receiving voltage at the receiving end when the three-dimensional energy transmitting coils work in coordination. If it does not change with the posture of the receiving end, the calculated theoretical phase differences α and β can generate a three-dimensional rotating spherical magnetic field. Otherwise, the Helmholtz coil 3, the saddle coil pair 4, and the saddle coil pair 5 in the three-dimensional energy transmitting coil 106 are tested separately. The actual transmitting current of the Helmholtz coil 3, the saddle coil pair 4, and the saddle coil pair 5 under the same working conditions is calculated according to the output voltage of the full-bridge rectifier circuit module 203 in the wireless energy receiving subsystem 2, thereby updating the decomposition coefficients A and B of the synthetic magnetic field intensity H in the three-dimensional space, and recalculating the phase differences α and β that can generate a rotating spherical magnetic field according to the formula in step 2.

[0024] Step 4) The control circuit module 102 generates three pairs of PWM signals with corresponding phase differences and inputs them into the three-dimensional energy transmitting coil 106 to generate an omnidirectional magnetic field.

[0025] The control signal sufficient to drive the MOSFET in the inverter circuit module 104 to work normally refers to: the TTL level PWM signal generated by the control circuit module 102 is boosted by the drive circuit module 103 to generate a control signal with an amplitude higher than the MOSFET turn-on threshold voltage Ugs(th).

[0026] The inverter circuit module 104 includes three groups of half-bridge circuits, each group of half-bridge circuits includes two MOSFETs, namely S1-S6.

[0027] like Figure 2As shown, the control circuit module 102 outputs three pairs (S1 / S2, S3 / S4, S5 / S6) of six PWM signals, each pair of PWM signals is complementary and symmetrical, and is driven by the drive circuit module 103 and respectively input into the six MOSFETs of the inverter circuit module 104 to realize the switch control function of the MOSFET.

[0028] like Figure 1 As shown, the LCC resonant compensation network 105 includes: three groups of series compensation inductors (Ls), parallel compensation capacitors (Cp) and coil series compensation capacitors (Cs), wherein: the series compensation inductors are power inductors with high current resistance, the parallel compensation capacitors are ceramic capacitors with high temperature stability, and the coil series compensation capacitors are high-voltage CBB capacitors that can withstand high-frequency current.

[0029] like Figure 1 As shown, the wireless energy receiving subsystem 2 includes: an energy receiving coil 201, a resonant compensation capacitor 202, a full-bridge rectifier circuit module 203 and a voltage stabilizing circuit module 204 which are connected in sequence, wherein: the resonant compensation capacitor 202 is connected in series with the energy receiving coil 201 to form a series resonant network; the full-bridge rectifier module 203 converts the AC voltage sensed by the receiving coil 201 into a DC voltage, and outputs it to the voltage stabilizing circuit module 204, and the voltage stabilizing circuit module 204 stabilizes the rectified voltage at the required value and outputs it to the internal circuit of the implantable / interventional diagnostic and treatment equipment.

[0030] The energy receiving coil 201 is a single-dimensional densely wound coil, such as a single-dimensional hollow cylindrical coil, which is wound on a magnetic core with high magnetic permeability.

[0031] The resonant compensation capacitor 202 is a ceramic capacitor with high temperature stability.

[0032] like Figure 3 As shown in (a), the three-dimensional energy transmitting coil 106 comprises: a pair of Helmholtz coils 3 whose normal lines are arranged parallel to the axis direction of the cylindrical coil frame, and two pairs of saddle coil pairs 4, 5 whose normal lines are perpendicular to the normal direction of the Helmholtz coils, wherein: the Helmholtz coil 3 as the innermost coil is wound on the cylindrical coil frame for generating a magnetic field in the z direction, the first saddle coil pair 4 is wound on the outer layer of the Helmholtz coil 3 for generating a magnetic field in the y direction, and the second saddle coil pair 5 is wound on the outer layer of the saddle coil pair 4 for generating a magnetic field in the x direction, and the three pairs of coils are orthogonally decoupled from each other and form a cylindrical structure.

[0033] The three-dimensional energy transmitting coils 106 are all wound with Litz wires of the same wire diameter.

[0034] like Figure 3As shown in (b), the first and second saddle coil pairs 4, 5 are both composed of a saddle coil 6 and a saddle coil 7 arranged opposite to each other and connected in series, and they are wound in the same direction to generate a magnetic field in the same direction.

[0035] Insulating material is provided between the two layers of coils in the first and second saddle-shaped coil pairs 4 and 5 .

[0036] After specific actual experiments: the diameter of the cylindrical coil skeleton is 640mm; the radius and spacing of the Helmholtz coil are both 320mm, the length of the saddle coil pair is 770mm, the center angle is 150°, and the three sets of transmitting coils are all 30×2 turns; the diameter of the receiving coil is 15mm, the length is 14mm, and it is wound in 3 layers, with 120 turns per layer; the load is 30Ω, and under the condition of a DC power supply voltage of 40V, the receiving end can receive at least 532mW of energy in any posture, which can meet the energy requirements of implantable / interventional diagnostic and treatment equipment.

[0037] like Figure 4 (a) shows the relationship between the amplitude of the magnetic field strength H at the center of the three-dimensional energy transmitting coil 106 and time obtained by simulation calculation. When the phase differences α and β are set appropriately, the theoretical synthetic magnetic field strength value is H0. The simulation results show that the synthetic magnetic field strength remains stable and does not change with time.

[0038] like Figure 4 (b) shows that the change trajectory of the synthetic magnetic field intensity H vector at the center point of the three-dimensional energy transmitting coil 106 obtained by simulation calculation within one cycle of the excitation signal is a spherical surface in three-dimensional space, indicating that the direction of the magnetic field changes with time and can point to any direction of the spherical surface, that is, the synthetic magnetic field sweeps all angles of the spherical surface within one cycle. Therefore, no matter what posture the single-dimensional energy receiving coil is in, the induced electromotive force remains unchanged, and can stably provide energy for implantable / interventional diagnostic and treatment equipment.

[0039] In practical applications, due to the existence of coil internal resistance or the fact that the coil is not in a fully resonant state, the actual value of the current flowing into the Helmholtz coil 3, the saddle coil pair 4 and the saddle coil pair 5 may deviate from the theoretical value. Therefore, the phase differences α and β derived by theoretical calculation do not produce completely ideal three-dimensional rotating spherical magnetic fields, and the control signal phase difference needs to be further optimized based on the feedback of the actual current value.

[0040] Directly measuring the transmitting current flowing through the transmitting coil requires adding an additional current detection circuit. The induced electromotive force output by the energy receiving coil is proportional to the magnetic field strength generated by the transmitting coil, and the magnetic field strength is proportional to the transmitting current. Therefore, the actual transmitting current can be calculated by detecting the voltage output by the energy receiving coil.

[0041] Compared with the prior art, the device adopts a coupling structure of a three-dimensional energy transmitting coil and a one-dimensional energy receiving coil. By inputting three sets of phase-controllable control signals, the three-dimensional energy transmitting coil can generate a uniform omnidirectional rotating magnetic field, so that the one-dimensional energy receiving coil can receive the same energy in any posture at the same position, ensuring the stability of the received energy. The proposed PWM control signal phase difference optimization control strategy is simple and easy to implement, does not require an additional current detection circuit, and reduces the complexity of the system. The present invention uses a three-dimensional energy transmitting coil composed of a pair of Helmholtz coils and two pairs of saddle coils to increase the internal working space to facilitate human access and cover the abdominal examination area of ​​the human body, which is convenient for clinical use of implant / interventional diagnosis and treatment equipment, such as capsule endoscopes, magnetically controlled capsule endoscopes, gastrointestinal micro-robots, etc. for disease diagnosis and treatment. In addition, the omnidirectional wireless energy transmitting subsystem and the wireless energy receiving subsystem of the present invention constitute an LCC-S resonant compensation structure. Compared with the traditional SS type compensation structure, the transmitting current of the transmitting end is controllable, and the receiving voltage of the receiving end does not change with the load, which is conducive to the stable operation of the implant / interventional diagnosis and treatment equipment under any working state.

[0042] The above-mentioned specific implementation can be partially adjusted in different ways by those skilled in the art without departing from the principle and purpose of the present invention. The protection scope of the present invention shall be based on the claims and shall not be limited by the above-mentioned specific implementation. Each implementation scheme within its scope shall be subject to the constraints of the present invention.

Claims

1. An omnidirectional wireless energy transmission system for implantable / interventional diagnostic and therapeutic equipment, characterized in that: include: An omnidirectional wireless energy transmitting subsystem placed outside the body for generating an alternating rotating magnetic field of constant intensity and a wireless energy receiving subsystem for wirelessly receiving electrical energy through electromagnetic induction, wherein: the wireless energy receiving subsystem forwards the received wireless energy to the internal circuit of the implantable / interventional diagnostic and treatment device; The omnidirectional wireless energy transmitting subsystem comprises: a phase-adjustable signal control unit, an LCC resonance compensation network and a three-dimensional energy transmitting coil connected in sequence; The three-dimensional energy transmitting coil comprises: a pair of Helmholtz coils whose normal lines are arranged parallel to the axis direction of the cylindrical coil frame and two pairs of saddle-shaped coil pairs whose normal lines are perpendicular to the normal lines of the Helmholtz coils, wherein: the Helmholtz coil as the innermost coil is wound on the cylindrical coil frame to generate a magnetic field in the z direction, the first saddle-shaped coil pair is wound on the outer layer of the Helmholtz coil to generate a magnetic field in the y direction, and the second saddle-shaped coil pair is wound on the outer layer of the saddle-shaped coil pair to generate a magnetic field in the x direction, and the three pairs of coils are orthogonally decoupled from each other and form a cylindrical structure.

2. The omnidirectional wireless energy transmission system for implantable / interventional diagnostic and therapeutic equipment according to claim 1 is characterized in that: The signal control unit generates three pairs of six-channel PWM signals through internal programming, and provides the output three-way square wave signals to the LCC resonance compensation network through the driving circuit and the inverter circuit. The LCC resonance compensation network converts the input three-way square wave signals into three-phase sinusoidal AC signals through first-order LC filtering and second-order LC resonance. The three-dimensional energy transmitting coil flows through the three-phase sinusoidal AC signal, thereby generating a three-dimensional alternating magnetic field; In the three pairs of six PWM signals: the first group of control signals is defined as zero phase, and the phase differences α and β between the second and third groups of signals and the first group of control signals are determined by the phase difference optimization control strategy; The phase difference optimization control strategy is: as well as Under the premise of , the phase differences α and β are calculated, where A and B are the decomposition coefficients of the synthetic magnetic field intensity H in three-dimensional space, and A and B satisfy: K x , K yz are the proportional relationship between the magnetic field strength generated by the Helmholtz coil and the saddle coil pair and the current flowing into the coil, ω0 is the system operating angular frequency, I m is the amplitude of the current flowing through the transmitting coil.

3. The omnidirectional wireless energy transmission system for implantable / interventional diagnostic and therapeutic equipment according to claim 2 is characterized in that: The phase-adjustable signal control unit comprises: a power supply module and a control circuit module, a drive circuit module and an inverter circuit module respectively connected thereto, wherein: the control circuit module generates an initial three pairs of six-way PWM signals with a phase difference according to a phase difference optimization control strategy and outputs them to the drive circuit module; the drive circuit module converts the initial three pairs of six-way PWM signals into control signals sufficient to drive the MOSFET in the inverter circuit module to work normally, that is, the TTL-level PWM signal generated by the control circuit module generates a control signal with an amplitude higher than the MOSFET turn-on threshold voltage Ugs(th) after being boosted by the drive circuit module; the inverter circuit module generates a three-phase AC signal under the control of the three pairs of six-way control signals generated by the drive circuit module.

4. The omnidirectional wireless energy transmission system for implantable / interventional diagnostic and therapeutic equipment according to claim 3 is characterized in that: The phase difference optimization control strategy specifically includes: Step 1) Select a suitable series compensation inductor Ls, construct an LCC resonant compensation network, and connect the LCC resonant compensation network with the inverter circuit module and the three-dimensional energy transmitting coil; Step 2) Set the inverter circuit DC supply voltage U dc , where the theoretical emission current is only related to the DC supply voltage U dc is related to the series compensation inductance Ls, while the decomposition coefficients A and B of the synthetic magnetic field intensity H in three-dimensional space are only related to the theoretical emission current, thus: as well as The theoretical phase differences α and β of the control signals are calculated; Step 3) testing the receiving voltage of the receiving end when the three-dimensional energy transmitting coil works in coordination. If it does not change with the posture of the receiving end, the calculated theoretical phase differences α and β can generate a three-dimensional rotating spherical magnetic field. Otherwise, the Helmholtz coil 3, the saddle coil pair 4, and the saddle coil pair 5 in the three-dimensional energy transmitting coil are tested separately. The actual transmitting current of the Helmholtz coil 3, the saddle coil pair 4, and the saddle coil pair 5 under the same working conditions is calculated according to the output voltage of the full-bridge rectifier circuit module in the wireless energy receiving subsystem 2. The decomposition coefficients A and B of the synthetic magnetic field intensity H in the three-dimensional space are updated accordingly. The phase differences α and β that can generate a rotating spherical magnetic field are recalculated according to the formula in step 2; Step 4) The control circuit module generates three pairs of PWM signals with corresponding phase differences and inputs them into the three-dimensional energy transmitting coil to generate an omnidirectional magnetic field.

5. The omnidirectional wireless energy transmission system for implantable / interventional diagnostic and therapeutic equipment according to claim 4 is characterized in that: The inverter circuit module includes three groups of half-bridge circuits, each group of half-bridge circuits includes two MOSFETs; The control circuit module outputs three pairs of six-channel PWM signals, each pair of PWM signals is complementary and symmetrical, and after being driven by the drive circuit module, they are respectively input into the six MOSFETs of the inverter circuit module to realize the switch control of the MOSFETs; The LCC resonant compensation network includes: three groups of series compensation inductors (Ls), parallel compensation capacitors (Cp) and coil series compensation capacitors (Cs), wherein: the series compensation inductors are power inductors with high current resistance, the parallel compensation capacitors are ceramic capacitors with high temperature stability, and the coil series compensation capacitors use high-voltage CBB capacitors that can withstand high-frequency current.

6. The omnidirectional wireless energy transmission system for implantable / interventional diagnostic and therapeutic equipment according to claim 1, characterized in that: The wireless energy receiving subsystem includes: an energy receiving coil, a resonant compensation capacitor, a full-bridge rectifier circuit module and a voltage stabilizing circuit module connected in sequence, wherein: the resonant compensation capacitor and the energy receiving coil are connected in series to form a series resonant network; the full-bridge rectifier module converts the AC voltage sensed by the receiving coil into a DC voltage and outputs it to the voltage stabilizing circuit module, and the voltage stabilizing circuit module stabilizes the rectified voltage at the required value and outputs it to the internal circuit of the implantable / interventional diagnostic and treatment equipment.

7. The omnidirectional wireless energy transmission system for implantable / interventional diagnostic and therapeutic equipment according to claim 1 is characterized in that: The three-dimensional energy transmitting coils are all wound with Litz wires of the same wire diameter, and the first and second saddle coil pairs are both composed of saddle coils arranged opposite to each other and connected in series, and they are wound in the same direction to generate a magnetic field in the same direction.

8. The omnidirectional wireless energy transmission system for implantable / interventional diagnostic and therapeutic equipment according to claim 1 or 7, characterized in that: Insulating material is provided between the two layers of coils in the first and second saddle-shaped coil pairs.

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