WO2020139225A1

WO2020139225A1 - An optical apparatus for diagnosing testicular torsion by means of near-infrared light

Info

Publication number: WO2020139225A1
Application number: PCT/TR2019/050602
Authority: WO
Inventors: Murat Canpolat; Selcuk YUCEL
Original assignee: Akdeniz Universitesi
Priority date: 2018-12-25
Filing date: 2019-07-22
Publication date: 2020-07-02
Also published as: EP3902464A1; TR201820283A2; EP3902464A4

Abstract

The present invention relates to an optical apparatus that can diagnose the testicular torsion in a short time (~5 s) by measuring the light, of which wavelengths are of 650-675 nm and 915-965 nm, and its testicle illumination and reemission from the same surface.

Description

AN OPTICAL APPARATUS FOR DIAGNOSING TESTICULAR TORSION BY IViEANS OF

N E AR-! N F RARE D LIGHT

TECHNICAL FIELD OF THE INVENTIO

The present invention relates to an optica! apparatus developed for real-time diagnosing of the testicular torsion by means of near-infrared (Nl R) light without causing any damage to the patient.

PRIOR ART

in state of the art, it is known that the prevalence of the testicular torsion is 1/4000 among men under the age of 25, and if is not easy to diagnose it. Aldamone et ai. emphasize in their study that 25-30 percent of those applying to the hospital due to testicle pain is diagnosed with the testicular torsion. Delay in the initiation of the therapy for those patients may cause them to lose their testicles. Further, it is seen that 2-88 percent of the patients who are decided to have testicular torsion as a result of clinical examination and thus have undergo unnecessary surgery. This shows us the importance of correct diagnosis.

As Hod et al. (2004) states in their study, along with clinical therapy, it is seen that Doppler ultrasonography is commonly used in diagnosing of the testicular torsion and its sensitivity varies to 70-89 percent. However, the results of Doppler ultrasonography depend on the experience of the user and is subjective. Furthermore, it is disadvantageous that Doppler ultrasonography takes a long time, and its results are not reliable, particularly with small testicles it is shown in another study in state of the art that specificity and sensitivity of magnetic resonance imagining (MRG) in diagnosing the testicular torsion are of 93 and 100 percent (Terai et al., 2006). However, although the specificity and sensitivity of magnetic resonance imagining system are quite high, it is disadvantageous that the system is expensive, it takes a longer time to operate and is not easily available. In this method, it is a possibility that the patient loses his testicles because the time of diagnosing takes a long time. There is another diagnosis method known in nuclear scintigraphy, and it has better sensitivity compared to Doppler ultrasonography.

In addition to this, it is disadvantageous in the nuclear scintigraphy that catheter is placed in the vein, and the patient is exposed to radiation and the time of diagnosing takes a long time.

Within state of the art, studies for diagnosing the testicular torsion by means of using light in the wavelength range of 450-900 nm with Near Infrared Spectroscopy (NIRS) are carried out. For this purpose, light source and spectrometer are used in the wide band range (450-900 n ). Spectrometer system is relatively expensive. Another application of NIRS LEDs or lasers with multiple wavelengths have been used. Psln those systems, detection pulsation of arterioles has been used to diagnose the testicular torsion. Capraro at el. (2007) shows that near-infrared light spectrometer can measure oxygen level of blood in vein and artery swiftly. In this method, measurement results are obtained depending on that absorption spectra of oxyhemoglobin and deoxyhemoglobin are different. In the study conducted by Hallacogiu at el. (2009), NIRS used in the frequency domain to diagnose the testicular torsion. In this method, a diagnosis is performed on an animal model by measuring the intensity and phase of light that is sent on to the testicle and re-emits from the same surface after subjecting to the diffusion. Canpolai at ei. (2012) distinguished the normal testicle from the testicle with torsion in the study on an animal model by performing spectroscopical measurements in the transmission geometry by means of using near- infrared light.

The present invention relates to a diagnostic apparatus for testicular torsion allowing for fast, efficient, and safe measurement.

BRIEF DESCRIPTION and OBJECTS OF THE INVENTION

The present invention discloses an optical apparatus for diagnosing the testicular torsion by means of near infrared light (NIR) and operation method thereof.

An object of the invention is to efficiently diagnose the testicular torsion.

Another object of the invention is to perform a safe and real-time diagnosis without causing any damage to the patient.

Advantages of the inventive testicular torsion diagnosing apparatus are listed below:

- The apparatus is of 200 g and is carriabie.

- The apparatus performs measurements on the testicle with torsion for less than 10 seconds, and objectively gives the diagnosis result in reai-time.

- The apparatus may be employed not only in the hospital but also in smaller healthcare organizations.

Since the apparatus operates with a battery of 1.5 volts, it does not constitute any electrical risk in terms of the patient.

DESCRIPTION OF FIGURES

Figure 1 Absorption spectra of oxyhemoglobin and deoxyhemoglobin (wavelength range used: 650-675 nm and 915-965 nm).

Figure 2 Schematic view of the inventive optical apparatus developed to diagnose the testicular torsion.

Figure 3 Variation of the rate R (I red/I !R) for different DAC drive values (used for calibration purpose in the apparatus).

Figure 4 Rear view of the inventive optical apparatus developed to diagnose the testicular torsion.

Figure 5 Schematic representation of the electronic equipment of the inventive optical apparatus developed to diagnose the testicular torsion.

DESCRIPTION OF ELEIVIENTS/PARTS/COIVIPONENTS OF THE INVENTION Parts and components in the figures are enumerated to understand the inventive optical apparatus fully, and correspondence of every number is given below:

10) first wavelength range in which LED emits

20) second wavelength range in which LED emits

30) LED

40) Photodiode

50) Electronic display

60) Measurement button

70) LED charge indicator

80) On-Off button

90) Mini USB cable port

100) Battery

1 10) Analogous digital converter microprocessor

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a testicular torsion diagnosis apparatus operating by means of measuring the intensity of the light that is sent on to the testicle in two-different wavelengths and re-emits from the same surface after subjecting to the diffusion.

The inventive apparatus comprises at least one LED and optical probe with a photodiode, analog to digital converter (ADC), microprocessor, LED screen, battery. Probe portion in contact with the apparatus is oval such that it covers the testicle along its long axis.

The inventive apparatus comprises a probe having at least one LED emitting light to the subject to be diagnosed and at least one photodiode measuring the intensity of the light re-sent by the subject after subjecting to the diffusion, digital analog converter (DAC) controlling the LED current, ADC digitalizing the photodiode outlet and analogous data, microprocessor that evaluates measurement data taken from the background first and second wavelength together, sends the result value to LED screen and comprises a software embedded therein to carry out said processes, LED screen displaying the result values, rechargeable battery for wireless use, GN- OFF button for providing the apparatus with power, button pressed so as to measure when the apparatus is on the testicle, LEDs showing that batteries are recharged and low.

The operation method of the inventive testicular torsion apparatus is as below:

Placing the probe on the subject to be diagnosed,

Measuring the background light intensity for 0.01-3 second, originated from the ambient, before activating LED light by pressing on the measurement button of the apparatus,

Calculating an average value on the microprocessor by measuring the ambient light intensity for 5-1000 times,

Emitting red light from LED for 0.01-3 seconds to the subject,

Calculating an average value on the microprocessor by taking measurements of 5- 1000 times from the light reflected back from the subject through the photodiode, Emitting infrared (IR) light from LED for 0.01 -3 seconds to the subject,

Calculating an average value on the microprocessor by taking measurements of 5-1000 times from the light reflected back from the subject through the photodiode,

Eliminating the the ambient light on measurements by extracting the background measurement from the measurements taken from Red and I R wavelengths,

Measuring LED light intensity for both wavelengths driven in the different DAC values and determining the ratio between them depending on the DAC drive value and then identifying a calibration,

Detecting the existence of the iesticuiar torsion according to the determined parameter defined as a ratio between the measured light intensities

from the testis.

The subject mentioned in the operation method of the invention testicular torsion is a testicle.

LED employed in the inventive testicular torsion diagnosis apparatus performs emission in the full width at half maximum (FWHM)of 650-675 and 915-965 The light in said two-wavelength range does not have any ionizing effect on living creatures. Light intensity emitted from the LED is under 15 mW, meaning that it is significantly under the tissue-damaging limit.

The outer surface of the testicular torsion diagnosis apparatus is formed from preferably the plastic material. There is a LED (30) and a photodiode (40) in front of the apparatus. After the apparatus contacts with the testicle, it is turned on when pressed on the electronic indicator (50) button thereon. The first measurement is performed prior to the activation of LED (30). The measurement sampling rate of the apparatus is of 1 kHz, and it carries out preferably 800 measurements in a second and the average value thereof is calculated. The measurement is background measurement (l_a ) and is extracted from the measurement taken later. The reason that this measurement is carried out is to eliminate the ambient light intensity. Then, LED (30) emits red iight (650-675 nm) and the iight intensity emitting back from the testicle after diffusion is measured as stated above. After waiting period of 100-300 ms, LED emits infrared (IR) light (915-965) and measurements are carried out on the testicle in a similar way.

DAG, of which resolution is of 12 bit and of which output voltage is of 3.3 V, is employed to drive LED in the invention. The value 0 of DAC corresponds to 0 volts and the value 4096 thereof corresponds to 3.3 V.

Figure 1 shows the absorption spectra of oxyhemoglobin (Hb02) and deoxyhemoglobin (Hb) in the blood. Absorption spectra of Hb02 and Hb are equal to each other in 808 nm, and its wavelength is called a isosbestic point. Absorption of HHb is high (dashed line) than Hb02 below the isosbestic point, and above the isosbestic point is viceversa. One of the wavelengths used in the testicular torsion is under the isosbestic point, and its FWHM may vary between 660-675 n , and wavelength of the other is above the isosbestic point, and its FWHM wavelength may vary between 910-965 nm.

When pressed on the measurement button (60) to perform measurements, information on the electronic indicator (50) are erased, and In this manner, desired number of measurements may be carried out consecutively by pressing on the measurement button (60). On-Off button (80) in Figure 4 is employed to turn on-off the system. There is a rechargeable battery on the apparatus, wherein mini-USB cable port (90) is used to re-charge it. The electronic equipment of the apparatus can be seen in Figure 5, wherein analogo digital converter microprocessor (1 10) is fed by means of the battery (100). The analog digital converter microprocessor (1 10) output drives LED (30). The current that the LED light returning from the testicle forms on the photodiode (40) is converted into voltage and the ratio (L_ed/ii_R) of red-light intensity (L_ed) to the IR light intensity (l:_R) is displayed on the electronic indicator (50) after calculation and calibration on the analogous digital converter microprocessor (110).

The calculated ratio (l_red/l iR) gains different values on the normal testicle and the testicle with torsion. This is because Hb concentration is increased in the testicle with torsion. As can be seen in Figure 1 , red light is absorbed by Hb significantly. Therefore, the value L_ed reduces, and the ratio reduces accordingly. Because of that, the ratio value measured on the normal testicle is greater than the ratio value measured on the testicle with torsion. The cut-off value is determined between said ratios and measurements over the cut-off value is defined as normal, and measurement under the cut-off value is defined as torsion.

CALIBRATION OF THE APPARATUS

The objective of the calibration making independent the measured testis intensities for the both wavelengths from the LED output emissions for different DAC drive values. For this purpose, firstly, LED (30) is driven through increases of 125, of which DAC value is of 2000-4000, for red light emission. Afterward, the same process is performed for I R light and their values are measured by means of the photodiode and the related oscilloscope. Red light intensity lo,_re measured for each DAC drive value is IR light intensity I_0,IR , wherein variations of their ratios (K= io i_R according to DAC value is as seen Figure 3. As can be seen in Figure 3, as DAC value increases, the ratio K increases also. Therefore, the calibration value depends on the DAC value. Data in Figure 3 shows the following relation between K and DAC value.

K^O.0001 xDAC÷0.245

This equation is employed for calibration, and the ratio between light intensities is made free from the DAC drive value.

In order to separate the measurement obtained over the testicle from the light intensity in two- wavelengths emitted by the LED, measured value (OD) is divided by the calibration value. OD = «ire_d-lap)/(!_|R-lap))x(1/K).

Here, OD is the diagnostic parameter, wherein it is independent of LED light intensities.

REFERENCES:

Barada JH, et al., Testicular salvage and age-related delay in the presentation of testicular torsion. J Urol 1989; 142:746-8

Aidamone, A A, Valvo, JR, Altebarmakian, VK. and Rabinowitz, R: Acute scrotal swelling in children. J Pediatr Surg, 1984; 19: 581

Hod N, et al: The relative merits of Doppler sonography in the evaluation of patients with clinically and scintigraphically suspected testicular torsion. Isr Med Assoc J. 2004;6:13-15

Terai A, et al. Dynamic contrast-enhanced subtraction magnetic resonance imaging in diagnostics of testicular torsion. Urology 2006; 67: 1278-82.

Capraro GA, et al. Feasibility of using near-infrared spectroscopy to diagnose testicular torsion: an experimental study in sheep. Ann Emerg Med. 2007;49:519-525.

Hallacoglu B, Matulewicz RS, Paltiel HJ, et al. Noninvasive assessment of testicular torsion in rabbits using frequency-domain nearinfrared spectroscopy: prospects for pediatric urology. J Biomed Opt. 2009; 14:054027-054027

Canpolat M, Yucel S, Sircan-KOcuksayan A, Kol A, Kazanci HO, Denkgeken T,“Diagnosis of testicular torsion by measuring attenuation of dual wavelengths in transmission geometry across testis: an experimental study in a rat model,” Urology, 79(4), 966.e9-12, (2012)

Claims

1 Testicular torsion diagnosis apparatus, characterized by comprising a probe having at least one LED emitting light to the subject to be diagnosed and at least one photodiode detecting the light reflected back from the subject, analogous digital converter (ADC) used to drive LED through digital analog converter (DAC) and to digitalize the photodiode output voltage value, microprocessor averaging the background measurement value and the measurement values taken on the testicle in two-wavelengths and having an embedded software therein to calculate the diagnosis parameter, rechargeable battery for wireless use, at least one LED displaying battery level, ON-OFF button, and measurement button.

2, Apparatus, according to Claim 1 , characterized in that outer surface of the apparatus, is formed from a plastic material.

3, Apparatus according to Claim 1 , characterized in that the apparatus is in an oval from such that the probe portion is placed on the subject to be diagnosed along its long axis

4, Apparatus according to Claim 1 , characterized in that the apparatus is in a single piece structure such that it can be operated with a single hand and hand grips easily.

5, Apparatus according to any of previous Claims, characterized in that said subject is a testicle.

6, Apparatus according to Claim 1 , characterized in that the apparatus is in a form allowing for performing a new measurement whenever pressed on the measurement button.

7, The operation method of an apparatus according to Claim 1 , characterized by comprising: i) Placing the probe on the subject to be diagnosed, ii) Measuring the background light intensity for 0.01-3 second, originated from the environment, before activating LED light by pressing on the measurement button of the apparatus, calculating an average value on the microprocessor by measuring it for 5-1000 times, iii) Emitting red light from LED for 0 01-3 seconds to the subject, iv) Calculating an average value on the microprocessor by taking measurements of 5-1000 from the light reflected back from the subject and detected by the photodiode, v) Emitting infrared (!R) light from LED for 0.01-3 seconds to the subject, vi) Calculating an average value on the microprocessor by taking measurements of 5-1000 from the light reflected back from the subject and detected by the photodiode, vii) Eliminating effect of ambient light on measurements by extracting the background measurement from the measurements taken from Red and IR wavelengths, viii) Measuring LED light intensities of the both wavelengths driven in the different DAC values by means of microprocessor and determining the ratio between the measured intensities depending on the DAC drive value and then identifying a calibration parameter,

ix) Detecting existence of the testicular torsion according to the determined disgnosis parameter,

8, Method according to Claim 7, characterized in that it performs the first measurement in the DAC value being the maximum value.

9, The method according to Claim 7, characterized in that it performs the first measurement in the DAC value being the maximum value, when pressed on the measurement button and decreases gradually the DAC value In the photodiode saturation.

10, The method, according to Claim 7, characterized by taking the first measurement value without saturation

11, The method, according to Claim 7, characterized by performing measurements in the highest LED values without photodiode saturation.

12, Method according to Claim 7, characterized in that wavelengths of the light emitted to the subject in process steps (iii) and (v) are of in the range of 650-675 nm and 915- 965, respectively.

13, Method according to Claim 7, characterized in that the subject is a testicle.

14, Calibration method of an apparatus according to Claim 1 , characterized by comprising: performing LED drive with DAC and determining the variation depending on the DAC drive value by measuring the light intensity in each wavelength for different DAC voltage drive values

determining the relation between the ratios of different DAC drive values and measured LED light intensities in separate two wavelengths,

normalizing LED light intensities in different two wavelengths to a constant for different DAC drives by means of using said relation.