CN107684433B - A device and method for simultaneously detecting multiple physiological parameter indexes of a wound surface - Google Patents

Abstract

The invention discloses a device for detecting various physiological parameter indexes of a wound surface, comprising: a reflective photoelectric detection module, a sensitive film sensitive to the physiological parameters of the wound surface, and a transparent isolation layer film located between the sensitive film and a photoelectric device; The reflective photoelectric detection module consists of a photoreceiving tube, n light-emitting diodes (LEDs) and a driving circuit. The n kinds of sensitive films corresponding to LEDs of different wavelengths are laid out according to the positions corresponding to the reflected light path, and the photoelectric detection of multiple physiological parameters is multiplexed, so that various physiological parameters of the wound can be detected by using different wavelengths of light in time division , and realize in-situ online detection of various physiological parameters.

Description

A device and method for simultaneously detecting multiple physiological parameter indexes of a wound surface

technical field

The invention belongs to the field of biomedical engineering, and in particular relates to a device and a method for realizing time-sharing and in-situ online detection of multiple physiological parameters of a wound by using light of different wavelengths.

Background technique

There are about 65 million surgical patients in my country every year, and the application of bandage technology for wound treatment is very common. For surgical patients, an important problem faced is wound healing after surgery. The most commonly used method is to wrap the bandage and gauze in a state of compressive stress. This method is simple and easy, but once the wound is wrapped, the doctor cannot monitor the growth status of the wound in real time in situ, nor can it treat inflammation in real time. , and wound healing takes a long time, and the wound cannot be accurately observed and diagnosed during this long period of time. Even if it is an operation on the surface of the skin, the skin will heal in about 10-20 days. If a wound occurs during this period Early inflammation or other problems cannot be treated in time. For example, wound infection will not only lead to delayed wound healing, but also endanger the life of patients in severe cases. In clinical diagnosis, the invasive gold standard method is used in the early stage. Although the measurement is relatively accurate, it needs to constantly uncover the gauze to detect the wound state, which will cause secondary injury to the wound and increase the risk of secondary infection, and has Disadvantages such as high price, time-consuming and non-continuous measurement. Therefore, the use of biosensors sensitive to wound infection markers (such as PH) to detect wound conditions has important clinical guiding significance.

Based on this, people have proposed electronic bandage technology. The invention multiplexes the photoelectric detection of multiple physiological parameters, and can use different wavelengths of light to detect multiple physiological parameters in time division, including arterial blood oxygen saturation, pH value, lactic acid content, etc., to realize in-situ online detection of wounds with a tiny device Function of various physiological parameters.

Contents of the invention

In view of the above, the present invention proposes a device for simultaneously detecting multiple physiological parameters of wounds, through which various physiological parameters of wounds can be detected online in situ, including arterial blood oxygen saturation, pH, lactic acid content, etc.

Technical scheme of the present invention is:

A device for simultaneously detecting multiple physiological parameter indexes of a wound, characterized in that it includes:

It includes at least one photoreceiving tube, n light-emitting diodes LEDs with different wavelengths, and a reflective photoelectric detection module that controls the driving circuit of the light-emitting diodes LED;

Sensitive films sensitive to physiological parameters of the wound; and,

A transparent isolation layer film located between the sensitive film and the reflective photoelectric detection module.

The working principle is: n light-emitting diodes emit laser signals of different wavelengths in time, and the light signals are irradiated on the surface of the sensitive film through the transparent isolation layer film. The sensitive film changes color due to changes in physiological parameters. Different concentrations of parameters have different absorbance, and reflect different wavelengths of laser light. The reflected light passes through the transparent isolation layer film and enters the photoelectric receiving tube. The photoelectric receiving tube generates photocurrent or voltage after receiving the optical signal. By calculating the photocurrent or voltage The magnitude obtains the intensity of the light signal at different wavelengths, thereby obtaining the magnitude change of this physiological parameter.

Preferably, the transparent barrier film is a transparent film with a light transmittance greater than 70% and biocompatibility. Further preferably, the transparent barrier film is polydimethylsiloxane PDMS or polylactic acid PLA. The transparent isolation layer film prevents the wound surface fluid from corroding the reflective photoelectric detection module, and has a breathable effect at the same time.

Preferably, the thickness of the isolation layer film is 90-110 μm.

Preferably, the sensitive film is spin-coated on the transparent isolation layer film, and the sensitive film contacts the wound surface during operation to realize the sensing of physiological parameters of the wound surface.

Preferably, the thickness of the sensitive thin film is 1 μm-30 μm.

Preferably, the sensitive film is pH sensitive film, glucose sensitive film, lactic acid sensitive film, chloride ion sensitive film or metal ion sensitive film.

Preferably, the device includes n kinds of sensitive thin films corresponding to light-emitting diodes LEDs with different wavelengths one-to-one, and each sensitive thin film reflects the light emitted by its corresponding light-emitting diode LED to the photoelectric receiving tube. The light-emitting diode (LED) corresponding to the sensitive film is determined by performing an absorbance test on the sensitive film with an ultraviolet-visible spectrophotometer, and the absorbance resolution of the sensitive film is the highest under the light of the light-emitting diode (LED). In this way, multiple physiological parameters of the wound surface can be detected quickly and accurately at the same time.

A method for detecting multiple physiological parameters of wounds, using the above-mentioned device to multiplex photoelectric detection of multiple physiological parameters, using different wavelengths of light to time-division detect various physiological parameters of wounds, and realizing multiple physiological parameters in situ and online Parameter detection.

Compared with the prior art, the present invention has the beneficial effects of: by arranging the n kinds of sensitive films corresponding to LEDs of different wavelengths one by one according to the positions of the reflected light paths, the multiples of the wound surface can be detected by using different wavelengths of light in time division. A variety of physiological parameters can be detected simultaneously. It is in line with the development direction of future biosensors - miniaturization, multi-function and no discomfort.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the device for simultaneously detecting multiple physiological parameters of the wound surface provided by Example 1 and attached to the surface of the wound surface;

Fig. 2 is a schematic diagram of the structure of the device for simultaneously detecting multiple physiological parameters of the wound provided in Example 2 and attached to the surface of the wound.

Fig. 3 is a distribution diagram of blood oxygen saturation values measured by the device provided in Example 2;

Fig. 4 is the distribution figure of pH value that utilizes the device measurement that embodiment 2 provides;

FIG. 5 is a graph showing the distribution of blood oxygen saturation measured by using the reflective blood oxygen sensor provided in Example 2 without spin-coating the sensitive film.

Detailed ways

In order to describe the present invention more specifically, the technical solutions of the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example 1

Fig. 1 is a schematic diagram of the structure of a device for simultaneously detecting multiple physiological parameters of a wound provided by an embodiment of the present invention, which is attached to the surface of the wound. This includes: a reflective photoelectric detection module 1, a transparent isolation layer film 2 coated on the surface of the reflective photoelectric detection module 1, a pH sensitive film 31 spin-coated on the transparent isolation layer film 2, a lactic acid sensitive film 32, and a glucose sensitive film. 33 and wound 8. Wherein, the reflective photoelectric detection module 1 includes LED4, LED5, LED6 and photodiode 7 with optimal wavelength corresponding to each sensitive film.

Example 2

In this embodiment, only one kind of pH sensitive film is spin-coated on the transparent isolation layer film, and the pH sensitive film is completely coated on the transparent isolation layer film. As shown in Figure 2, the device provided in this embodiment includes: a reflective blood oxygen sensor 1 of model SFH7050, a PDMS 2 coated on the surface of the reflective blood oxygen sensor 1, and a pH sensitive film 3 spin-coated on the PDMS 2 and wound surface 8. Wherein, the reflective blood oxygen sensor 1 includes a red LED 4 , a green LED 5 , an infrared LED 6 and a photodiode 7 .

The pH-sensitive film 3 is prepared by coating the acid-base indicator dye molecules on the sol-gel precursor by sol-gel technology. Wherein, the acid-base indicator dye molecules include bromocresol green, bromocresol green sodium salt, methyl red and neutral red.

Sol-gel precursors are divided into three types: inorganic precursors, organic precursors, and organic-inorganic hybrid precursors. Among them, inorganic precursors include tetraethylorthosilicate (TEOS), tetramethoxysilane (TMOS) ; Organic precursors include γ-glycidyloxypropyltrimethoxysilane (GLYMO), methyltriethoxysilane (MTES), ethyltriethoxysilane modified (ETES) or phenyltrimethoxy Silane (FTMS); organic-inorganic hybrid precursor is obtained by mixing organic precursor and inorganic precursor in different proportions.

The thickness of the pH-sensitive film 3 is 10 μm. In order to achieve the best results among mechanical properties, optical transparency and response time of the pH-sensitive film, the volume ratio of the organic precursor to the inorganic precursor is 3:7 (1 mL in total). Prepared by the following method:

First, 1.2 mL of ethanol, 16.3 mg of bromocresol green sodium salt, 0.3 mL of γ-glycidyloxypropyltrimethoxysilane (GLYMO), 0.7 mL of tetraethyl orthosilicate (TEOS) and 0.4 mL of catalyst (0.1 M HCL) were mixed to prepare a sol, then homogenized in an ultrasonic bath for 10 min, aged at room temperature for 3 days, and then spin-coated onto PDMS by spin coating technology, and placed at room temperature for 3 days in the dark.

The light emitted by the LED in the reflective blood oxygen sensor SFH7050 passes through the isolation layer film and the sensitive film to irradiate the wound surface, and the scattering and absorption parts are removed. The reflected light is received by the photodiode and converted into an electrical signal proportional to the light intensity. The blood oxygen saturation calculation formula can be used to obtain blood oxygen saturation, electrical signals, light absorption when passing through tissues and blood vessels, which can be divided into pulsating components (such as arterial blood) and non-pulsating components (such as skin, tissue, venous blood, etc. ), which can be called alternating current (AC) and direct current (DC). Since the pH value of the wound does not change suddenly, the absorption of light by the pH-sensitive membrane is regarded as the DC part.

The device prepared in this example is placed on the surface of the wound, and based on the Lambert-Beer law, the electrical signal is obtained by measuring the red light and the infrared LED light, that is, the photoplethysmogram (PPG), and the calculation formula of the arterial blood oxygen saturation The blood oxygen saturation was obtained, and the results are shown in Figure 3.

The device prepared in this example was placed in different pH buffer solutions with a pH value of 5-9 and an interval of 1, and the electrical signal obtained by measuring the light emitted by the green LED was used to characterize the pH value, and the results are shown in FIG. 4 .

The reflective blood oxygen sensor provided in this embodiment is placed on the wound surface when the PH sensitive film is not spin-coated, and the PPG signal obtained by measuring the red light and the infrared wavelength light is used to calculate the blood oxygen saturation in combination with the Lambert-Beer law. Calculated as follows:

[HbO ₂ ] and [Hb] represent the concentrations of oxygenated hemoglobin and deoxygenated hemoglobin, respectively.

α(HbO ₂ ,λ _Red ),α(HbO ₂ ,λ _IR ),α(Hb,λ _Red ),α(Hb,λ _IR ) are the pairs of HbO ₂ and Hb respectively

Absorption coefficient for red and infrared light. R is calculated as follows:

According to the spectral absorption characteristics of HbO ₂ /Hb, the absorption coefficient satisfies the following relationship:

α(Hb,λ _Red )＞＞α(HbO ₂ ,λ _Red ) (4)

α(Hb,λ _IR )≈α(HbO ₂ ,λ _IR ) (5)

Therefore, formula (1) can be simplified as:

Calibrate A and B using a commercial photo-oximeter.

The blood oxygen saturation was calculated by the above formula, and the result is shown in Figure 5. Corresponding to each measurement result, there is only a difference of 0.1%-0.2% in blood oxygen saturation between the device for detecting multiple physiological parameters of the wound surface provided by the embodiment of the present invention and the non-spin-coated pH-sensitive film test. This result indicates that the presence of the pH-sensitive film does not affect the measurement of blood oxygen saturation.

Therefore, this embodiment can realize the in-situ online detection of the arterial blood oxygen saturation and pH value of the wound.

The above-mentioned specific embodiments have described the technical solutions and beneficial effects of the present invention in detail. It should be understood that the above-mentioned are only the most preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, supplements and equivalent replacements made within the scope shall be included in the protection scope of the present invention.

Claims (6)

1. A device for simultaneously detecting multiple physiological parameter indexes of a wound surface is characterized by comprising:

The device comprises a reflection type photoelectric detection module, a photoelectric detection module and a control module, wherein the reflection type photoelectric detection module at least comprises a photoelectric receiving tube, n Light Emitting Diodes (LEDs) with different wavelengths and a driving circuit for controlling the LEDs;

The system comprises n sensitive films sensitive to the physiological parameters of the wound surface, wherein the n sensitive films correspond to n Light Emitting Diodes (LEDs) with different wavelengths one by one, and each sensitive film reflects light emitted by the corresponding LED to a photoelectric receiving tube; and the number of the first and second groups,

the transparent isolating layer film is positioned between the sensitive film and the reflective photoelectric detection module;

the sensitive film is coated on the transparent isolating layer film in a spinning mode, and the sensitive film is in contact with the wound surface when in work, so that the physiological parameters of the wound surface are sensed.

2. a device for simultaneously detecting multiple physiological parameter indicators of a wound as claimed in claim 1, wherein the transparent isolation layer film is a transparent film with a light transmittance of more than 70% and biocompatibility.

3. A device for simultaneously detecting multiple physiological parameter indicators of a wound as claimed in claim 2, wherein the transparent isolation layer film is polydimethylsiloxane PDMS or polylactic acid PLA.

4. a device for simultaneously detecting multiple physiological parameter indicators of a wound as claimed in claim 1, wherein the thickness of the sensitive film is 1 μm to 30 μm.

5. The device for simultaneously detecting multiple physiological parameter indexes of a wound surface according to claim 1, wherein the sensitive film is a PH sensitive film, a glucose sensitive film, a lactic acid sensitive film, a chloride ion sensitive film or a metal ion sensitive film.

6. A method for simultaneously detecting multiple physiological parameter indexes of a wound surface is characterized in that the device of any one of claims 1 to 5 is used for multiplexing photoelectric detection of multiple physiological parameters, light with different wavelengths is used for time division detection of multiple physiological parameters of the wound surface, and in-situ on-line detection of the multiple physiological parameters is realized.