CN112569006B - Real-time skin flap thickness monitoring system in art based on microwave contactless - Google Patents
Real-time skin flap thickness monitoring system in art based on microwave contactless Download PDFInfo
- Publication number
- CN112569006B CN112569006B CN202011461742.6A CN202011461742A CN112569006B CN 112569006 B CN112569006 B CN 112569006B CN 202011461742 A CN202011461742 A CN 202011461742A CN 112569006 B CN112569006 B CN 112569006B
- Authority
- CN
- China
- Prior art keywords
- patch antenna
- monitoring system
- phase
- microwave
- metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
- A61B90/06—Measuring instruments not otherwise provided for
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
- A61B90/06—Measuring instruments not otherwise provided for
- A61B2090/061—Measuring instruments not otherwise provided for for measuring dimensions, e.g. length
Landscapes
- Health & Medical Sciences (AREA)
- Surgery (AREA)
- Life Sciences & Earth Sciences (AREA)
- Heart & Thoracic Surgery (AREA)
- Molecular Biology (AREA)
- Oral & Maxillofacial Surgery (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Medical Informatics (AREA)
- Pathology (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Length-Measuring Devices Using Wave Or Particle Radiation (AREA)
- Surgical Instruments (AREA)
Abstract
The invention discloses a microwave-based non-contact intraoperative real-time flap thickness monitoring system and a measuring and calculating method thereof. The microwave-based non-contact intraoperative real-time flap thickness monitoring system is simple in structure and low in cost, can penetrate into human tissues under the condition of not damaging epidermis and muscular tissues, and can measure and calculate the flap thickness by using a vector network analyzer according to the relation between microwave phase and wavelength.
Description
The technical field is as follows:
the invention relates to the field of interdisciplines of microwave, radio frequency and biomedical instruments and equipment, in particular to a monitoring system for measuring and calculating distance based on the relation between electric field phase and wavelength and a measuring and calculating method thereof.
Background art:
in recent years, radio frequency circuits and microwave technology are rapidly developing and gradually permeating various civil fields, such as medical equipment field. Microwave technology plays an important role in medical diagnosis and the like, a large number of microwave medical devices are in clinical application in hospitals, and meanwhile, a plurality of novel microwave medical devices are also being developed, so that microwaves penetrate into the aspect of the medical field.
In the process of performing certain endoscopic surgical operations (such as breast endoscopic surgical operations), because a skin flap with a certain thickness needs to be reserved to prevent postoperative ischemic necrosis, the distance between a subcutaneous scalpel and the epidermis needs to be known, but due to the shielding of the epidermis, an incision is too far away from an operation part, so that the direct observation and measurement cannot be performed by naked eyes. Therefore, how to determine the thickness of the flap is a technical problem to be solved urgently.
The invention content is as follows:
the invention aims to solve the technical problem of providing a microwave-based non-contact intraoperative real-time flap thickness monitoring system which is simple in structure and low in cost and is used for obtaining the distance (flap thickness) between a metal scalpel and the skin based on the relation between the phase change and the wavelength of an electric field, and the system is convenient for real-time monitoring in the surgical process.
The technical scheme includes that the real-time intraoperative flap thickness monitoring system based on microwave non-contact comprises a patch antenna and a vector network analyzer, wherein the patch antenna sequentially comprises a top metal layer, a dielectric layer and a bottom metal layer from a top layer to a bottom layer, the patch antenna is also provided with an input port for connecting an SMA connector, the input port is connected with the vector network analyzer through a connecting wire, and a metal patch is arranged on a groove of the top metal layer.
As a preferable technical scheme, the patch antenna is a 6-10GHz patch antenna.
As a preferable technical scheme, the dielectric layer is a square PCB made of F4B, the dielectric constant is 2.65, and the loss tangent is 0.017.
As a preferable technical solution, the patch antenna is a 9.8GHz patch antenna.
The invention also provides a measuring and calculating method of the intraoperative real-time flap thickness monitoring system based on microwave non-contact, which comprises the following steps,
firstly, a patch antenna is placed right above skin where a metal surgical blade is placed, and S11 parameters of the antenna in a time domain are measured by related equipment;
step two, when the electromagnetic wave meets the epidermis, the electromagnetic wave is reflected once and received by the patch antenna, the phase at the S11 parameter frequency point is correspondingly changed once, and the phase at the frequency point at the moment is recorded as
Step three, because only a part of the electromagnetic waves are reflected when the electromagnetic waves meet the epidermis, the other part of the electromagnetic waves penetrate the skin, are reflected for the second time when the electromagnetic waves meet the metal blade and are received by the patch antenna again, the phase of the S11 parameter of the patch antenna at the moment has corresponding change again, and the phase of the S11 parameter frequency point at the moment is recorded as
Step four, determining the distance h between the metal blade and the top fat through the steps,
wherein the content of the first and second substances,
n is the number of complete wavelengths of electromagnetic waves between the epidermis and the subcutaneous metal scalpel, and n can be connectedAnd calculating by an over-decoupling algorithm to obtain the wavelength of the electromagnetic wave with the lambda g of 9.8GHz in the fat.
As a preferred technical solution, the related device is a vector network analyzer.
Compared with the prior art, the invention has the following advantages after adopting the technical scheme: by the monitoring system, the microwaves of the patch antenna can penetrate into human tissues without contact under the condition of not damaging epidermis and muscular tissues, the thickness of the flap is measured and calculated by using the vector network analyzer according to the relation between the microwave phase and the wavelength, and the distance between subcutaneous metal (scalpel) and the epidermis can be accurately obtained as long as the specific phase difference is known; the measuring and calculating method adopted by the monitoring system related to the invention is simpler, so the architecture of the whole system is simpler, and the cost is lower.
Description of the drawings:
fig. 1 is a schematic diagram of a patch antenna in the present system and a parameter labeling diagram.
Fig. 2 shows the S11 parameter of the patch antenna used in the present system when it is free from obstructions in free space.
Fig. 3 is the phase of the S11 parameter for the patch antenna used in the present system when free space is clear.
FIG. 4 is a schematic diagram of the present system simulating in a full-wave three-dimensional electromagnetic simulation software CST DESIGN ENVIRONMENT ENVIRONMENT.
Fig. 5 is a distribution diagram of the electric field intensity in the y direction when the system is simulated in a full-wave three-dimensional electromagnetic simulation software CST DESIGN enviromenent ENVIRONMENT.
Fig. 6 is a schematic view of placement of a subcutaneous metal scalpel at the bottom layer of fat.
The specific implementation mode is as follows:
the invention is further described with reference to the following figures and detailed description:
as shown in fig. 1-6, a microwave-based non-contact intraoperative real-time flap thickness monitoring system comprises a patch antenna and a vector network analyzer, wherein the patch antenna sequentially comprises a top metal layer, a dielectric layer and a bottom metal layer from a top layer to a bottom layer, the patch antenna is also provided with an input port for connecting an SMA connector, the input port is connected with the top metal layer, the input port is connected with the vector network analyzer through a coaxial cable, and a metal patch is arranged on a groove of the top metal layer. In this embodiment, the dielectric layer is a square PCB made of a material
F4B, the dielectric constant is 2.65, the loss tangent is 0.017, and the patch antenna is a 9.8GHz patch antenna.
The monitoring system mainly aims at monitoring the thickness of a skin flap (the distance between a metal scalpel and the skin) in real time in an operation, and particularly relates to a monitoring system for obtaining the distance between a subcutaneous metal scalpel and the epidermis based on the relation between the phase change of an electric field and the wavelength. Because the phase difference and the wavelength of the electric field generated by the patch antenna at the position of the epidermis and the subcutaneous metal scalpel have a certain relation, the distance between the metal scalpel and the skin surface can be calculated, and the specific relation is as follows: distance between two adjacent plates
Wherein λgIs the wavelength of the light inside the skin,
is the electric field phase difference between the skin surface and the metal scalpel. In the practical use process, the phase of the electric field can be replaced by the phase of S11 according to the definition of the S parameter, when the electric field energy meets the epidermis, a part of energy is reflected, the other part of energy penetrates through the skin and continuously radiates to the inside of the skin, when the electric field energy meets the metal blade, the primary reflection is generated, the phase difference between the two reflections has a certain relation with the wavelength of the electromagnetic field inside the skin, and then the distance between the metal surgical blade and the skin can be obtained.
Since the phase of the electric field is not directly available, according to the definition of the S parameter: the phase of the S parameter is the difference between the phase of the input wave and the phase of the output wave, i.e., theoretically, the phase of S11 can be calculated to some extent as a distance in place of the phase of the electric field at the time of measurement.
Therefore, the measuring and calculating method of the microwave non-contact intraoperative real-time flap thickness monitoring system comprises the following steps,
the method comprises the following steps that firstly, a patch antenna is arranged right above skin with a metal surgical blade, S11 parameters of the antenna in a time domain are measured by a vector network analyzer, and the patch antenna is a 9.8GHz patch antenna;
step two, when the electromagnetic wave meets the skin epidermis, the electromagnetic wave is reflected once and received by the patch antenna, at the moment, the phase at the S11 parameter frequency point is changed once correspondingly, and the phase at the frequency point at the moment is recorded as
Step three, because only a part of the electromagnetic waves are reflected when the electromagnetic waves meet the epidermis, the other part of the electromagnetic waves penetrate the skin, are reflected for the second time when the electromagnetic waves meet the metal blade and are received by the patch antenna again, the phase of the S11 parameter of the patch antenna at the moment is changed correspondingly again, and the phase of the S11 parameter frequency point at the moment is recorded as the phase of the S11 parameter frequency point through the vector network analyzer again
Step four, finally determining the distance h between the metal blade and the top fat through the steps,
wherein the content of the first and second substances,
n is the number of complete wavelengths of electromagnetic waves between the epidermis and the subcutaneous metal scalpel, n can be calculated by a decoupling algorithm, and lambdagIs the wavelength of electromagnetic waves in fat at 9.8 GHz. It should be noted that since this is the phase of S11, if it is not divided by 2, the calculated distance will be the path length traveled by the transmission and reception of the electromagnetic wave.
To further verify the feasibility and reliability of the present monitoring system,the system is simulated in a full-wave three-dimensional electromagnetic simulation software CST DESIGN ENVIRONMENT ENVIRONMENT, specifically, as shown in FIG. 4, the thickness of fat in the figure is set to be 3mm, the dielectric constant is set to be 5.97, the size of the fat is 30mm by 30mm, the thickness of the epidermis is set to be 0.5mm, the dielectric constant is set to be 18.51, the size of the epidermis is 30mm by 30mm, and the patch antenna is placed at a position 4.5mm right above the epidermis. Further, the y-direction electric field intensity distribution diagram of the system shown in fig. 5 when the system is simulated in the full-wave three-dimensional electromagnetic simulation software CST DESIGN ENVIRONMENT ENVIRONMENT is obtained, the phase of the electric field at the uppermost end of the epidermis is about 65 degrees, the phase is about 40 degrees when the lowermost end of the epidermis is reached, and the wavelength lambda in the skin of the calculated surface isg epidermis7.1mm, the thickness of the epidermis is approximately as determined by the above formula
Close to the set thickness of the epidermis. Meanwhile, the phase of the electric field is about 40 ° at the uppermost end of the fat, and then the phase of the electric field becomes 0(360 °), and the phase of the electric field becomes about 325 ° by the lowermost end of the fat, i.e., it is
Due to the fact that
Is the electric field phase, not the phase of S11, so the wavelength lambda in fat is calculated without dividing by 2g fat12.53mm, thickness of fat
Also close to the set fat thickness. It can be seen that the idea of measuring distance by electric field phase change is feasible, and the measured data is also reliable.
In addition, the antenna in the system is simulated in a full-wave three-dimensional electromagnetic simulation software CST DESIGN ENVIRONMENT ENVIRONMENT, and the relevant size is calculated by the software, and is shown in the following table:
it can be seen that the present invention has the following advantages: by the monitoring system, the microwaves of the patch antenna can penetrate into human tissues under the condition of not damaging epidermis and muscular tissues, the measurement and calculation of the flap thickness are completed by utilizing the vector network analyzer according to the relation between the microwave phase and the wavelength, the distance between subcutaneous metal (scalpel) and the epidermis can be accurately obtained as long as the specific phase difference is known, and the flap thickness can be further obtained in the operation. The measuring and calculating method adopted by the monitoring system is simple, the architecture of the whole system is simple, and accordingly, the cost is low, and the system is suitable for popularization and application.
The foregoing is illustrative of the preferred embodiments of the present invention only and is not to be construed as limiting the claims. All the equivalent structures or equivalent process changes made by the description of the invention are included in the scope of the patent protection of the invention.
Claims (3)
1. The utility model provides a real-time skin flap thickness monitoring system in art based on microwave contactless which characterized in that: the monitoring system comprises a patch antenna and a vector network analyzer, wherein the patch antenna comprises a top metal layer, a dielectric layer and a bottom metal layer from top to bottom in sequence, the patch antenna is also provided with an input port for connecting an SMA connector, the input port is connected with the vector network analyzer through a connecting wire, a metal patch is grooved on the top metal layer, the monitoring system comprises the following steps,
firstly, a patch antenna is placed right above skin with a metal surgical blade, and S11 parameters of the antenna in a time domain are measured by related equipment;
step two, when the electromagnetic wave meets the epidermis, the electromagnetic wave is reflected once and received by the patch antenna, and at the moment, the phase at the S11 parameter frequency point hasRecording the phase position of the frequency point at the moment as
Step three, a part of electromagnetic waves penetrate through the skin, generate second reflection when encountering the metal blade and are received by the patch antenna, the phase of the S11 parameter changes correspondingly again at the moment, and the phase of the S11 parameter frequency point at the moment is recorded as
Step four, determining the distance h between the metal blade and the top fat through the steps,
wherein the content of the first and second substances,
n is the number of complete wavelengths of electromagnetic waves between the epidermis and the subcutaneous metal scalpel, lambdagIs the wavelength of the electromagnetic wave of the patch antenna in fat.
2. The microwave-based non-contact intraoperative real-time flap thickness monitoring system of claim 1, wherein: the patch antenna is a 6-10GHz patch antenna.
3. The microwave-based non-contact intraoperative real-time flap thickness monitoring system of claim 2, wherein: the patch antenna is a 9.8GHz patch antenna.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011461742.6A CN112569006B (en) | 2020-12-11 | 2020-12-11 | Real-time skin flap thickness monitoring system in art based on microwave contactless |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011461742.6A CN112569006B (en) | 2020-12-11 | 2020-12-11 | Real-time skin flap thickness monitoring system in art based on microwave contactless |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112569006A CN112569006A (en) | 2021-03-30 |
| CN112569006B true CN112569006B (en) | 2022-03-04 |
Family
ID=75132241
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011461742.6A Active CN112569006B (en) | 2020-12-11 | 2020-12-11 | Real-time skin flap thickness monitoring system in art based on microwave contactless |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112569006B (en) |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI58719C (en) * | 1979-06-01 | 1981-04-10 | Instrumentarium Oy | DIAGNOSTISERINGSANORDNING FOER BROESTKANCER |
| AU2003901660A0 (en) * | 2003-04-08 | 2003-05-01 | Commonwealth Scientific And Industrial Research Organisation | Microwave based monitoring system and method |
| CN2857244Y (en) * | 2005-08-03 | 2007-01-10 | 深圳国瑞通讯有限公司 | Combined mini-band patch antenna for mobile satellite communicator |
| GB0620060D0 (en) * | 2006-10-10 | 2006-11-22 | Medical Device Innovations Ltd | Surgical antenna |
| CN102280704B (en) * | 2011-05-13 | 2015-05-20 | 广东博纬通信科技有限公司 | Circular polarized antenna with wide wave beam width and small size |
| CN103941261B (en) * | 2014-04-16 | 2016-06-01 | 中国极地研究中心 | Phase sensitive formula fixed point surveys ice system |
| CN105264714B (en) * | 2014-04-22 | 2017-11-24 | 华为技术有限公司 | Multipolarization substrate integration wave-guide antenna |
| CN203942006U (en) * | 2014-05-12 | 2014-11-12 | 成都振芯科技股份有限公司 | A kind of fluting is realized the circularly polarization microstrip patch antenna of miniaturization |
| CN106910980A (en) * | 2017-03-08 | 2017-06-30 | 东华大学 | A kind of small-sized high-gain for microwave detection system orients broad-band antenna |
| CN106959306B (en) * | 2017-05-11 | 2019-11-12 | 天津大学 | A method of mammary tumor imaging is carried out using microwave reflection time domain S21 signal |
| CN109330592A (en) * | 2018-10-19 | 2019-02-15 | 天津大学 | Blood sugar concentration detection method based on ultra-wideband microwave S11 parameter |
-
2020
- 2020-12-11 CN CN202011461742.6A patent/CN112569006B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN112569006A (en) | 2021-03-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5993372B2 (en) | Embedded dielectric measurement system | |
| Rezaeieh et al. | Microwave system for the early stage detection of congestive heart failure | |
| Tang et al. | A model-driven framework to support development of serious games for game-based learning | |
| AlShehri et al. | 3D experimental detection and discrimination of malignant and benign breast tumor using NN-based UWB imaging system | |
| US20100007568A1 (en) | Antenna with Balun | |
| JP2014198067A (en) | Diagnostic system | |
| Sohani et al. | Microwave imaging for stroke detection: validation on head-mimicking phantom | |
| Nguyen et al. | High frequency breast imaging: Experimental analysis of tissue phantoms | |
| CN112569006B (en) | Real-time skin flap thickness monitoring system in art based on microwave contactless | |
| Zamani et al. | Frequency domain method for early stage detection of congestive heart failure | |
| Boologam et al. | On the design and development of planar monopole antenna for bone crack/void detection | |
| Top et al. | Microstrip antenna design with circular patch for skin cancer detection | |
| Aleef et al. | Design and measurement of a flexible implantable stripline-fed slot antenna for biomedical applications | |
| Sharma et al. | Permittivity measurement of biological tissues using interdigital capacitor based resonator | |
| Vendik et al. | Microwave diagnostics of osteoporosis | |
| Agu et al. | Investigation of dominant wave mechanism and optimal antenna excitation for body-centric wireless propagations | |
| Celik et al. | An experimental performance investigation of an ultra-wideband directional antenna in the microwave imaging of breast cancer tumor | |
| Ahmad et al. | Design and performance measurement of an on-body capacitively loaded planar inverted-F antenna for bio-medical applications | |
| Fritiss et al. | Design and characterization of a broadband PCB-based coaxial sensor for permittivity screening in skin cancer detection applications | |
| Modiri et al. | Experimental results for a novel microwave radiator structure targeting non-invasive breast cancer detection | |
| Reimann et al. | A cylindrical shaped theranostic applicator for percutaneous microwave ablation | |
| Sharma | Reflectometry analysis for skin cancer detection using a new millimeter-wave sensor in sub-THz range | |
| Besnoff et al. | Single-wire RF transmission lines for implanted devices | |
| Bialkowski et al. | Compact reflectometers for a wideband microwave breast cancer detection system | |
| Malesevic | Wearable Microwave Antennas for Brain Stroke Imaging |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |