MONITORING NEEDLE PUNCTURE IN SURGICAL OPERATIONS

Abstract: A system for monitoring the advancement of a needle (1) detects the puncture of the peritoneum and of the entrance into the abdominal cavity at the beginning of a laparoscopic operation. The need of such a system is mostly recognized in re-operation cases and in operations on overweight patients with lots of fat tissue. A sensor (3) capable of measuring vibration during punctures is placed and coupled on any location on the needle (1) and is protected against thermal and/or mechanical interactions. Initially the puncture information is relayed to the user of the system via a visual display such as an oscilloscope (6). A computer (8) with communication capabilities (I/O cards) or other means of processing could be added to the system. With the use of a computer (8) the signal can be processed and transformed to other means of display: colour leds, graphs, an audio indicator (change of tone, volume etc...) or a haptic indicator.

Description: MONITORING NEEDLE PUNCTURE IN SURGICAL OPERATIONS The invention is the design and building of a system that for the fust time on an international basis will measuie and relay to surgeons infoi mation about the puncture of tissues duπngs surgical operations. A specific and immediate application of this mvention is the objective diagnosis of the punctuπng via a puncturing needle of the peritoneum and the entrance in the abdominal cavity at the beginning of a laparoscopic operation. At this point we would like to briefly describe the theoretical backgiound of the present technique for this type of surgery : Lapaioscopic operations increase on a day to day basis. The fast healing of the patient as well as the decrease of post-sui gery pain makes this type of sui gei y moi e desn able than the classical open surgery operation. Until now, at the beginning ot a laparoscopic operation the surgeon punctures the tissues until he/she reaches the peritoneum so that he/she can insert the laparoscopic tools in the abdominal cavιt\ This punctui e is done in two ways- The fust one is the 'open' method wheie the surgeon cuts open down to the peritoneum and punctures through using immediate visual feedback This way is time consuming (it takes about 10 minutes and it can also give use to technical difficulties during the opei ation because this way allows the escape of CΩ2 fi om the peπtonaic cavity due to the large clearance between the insei ted ti otai and tissues resulting from this method. Finally this method results in a cut XA cm lon_, which is less desirable than the 1 cm cut resulting from punctui e using the Vei ess needle. The second way is the 'blind' method during which the punctui e is empπ icalh diagnosed with the help of naturally genei ated vibrations that get l elayed thi ough the punctuπng needle to the hand of the sui geon and excite his/hei sense of touch The invention of this disclosure described is the design and building of a system thai for the fust time will measure the needed information for the objective verification ol puncture and will relay this infoimation to the suigeon. In othei woi d the system suggested will provide information that will ensure the objective venfication ol punctuπng that until now is done empirically. The impoi tance of this system is even more obvious in the case of resuigery and operations on overweight patients The above described design and built of such a system that ob]ectιvely veπfies the puncture in contrast to the empiπcal diagnosis of puncture is a state of the ai t design and is of gieat importance and applicability. The system that I suggest exploits a lot of elements of human manipulation and at this point I would like to mention the basics of human manipulation This bπef descπption is included so as to show that the contribution of the pioposed system to the objective verification of punctui e is given for the following teason The invention is the realization of measurement of physical parameters of human manipulation during the puncture and manipulation of human tissue and othei similar mateπals The proposed system measures and uses these parameters in a similar way humans use them duπng barehand manipulation. Manipulation consists of a series of events and phases. Phases are simple subtasks of human manipulation whose boundanes are defined by the events. Events are the indications of the status of h uman manipulation and help in the serial coordination of activities foi the successf ul completion of a task. For example, the instance of contact of the fingers with an object is the event of contact. When this event is detected fi om the subject thai pei forms a certain task the subsequent activities are coordinated in such a way so as to lead to the successful lift of the object (if for example the desii ed task is to gi asp and lift the object). These subsequent activities include the increase of the load foi ce and the lift of the object. We could also describe events as discontinuities of the manipulation parameters. For example, before the lift of the object the force on the fingers (and the object) is 0 since there is no contact between the fingers and the object. Right after contact the force is no longer 0. These events in human manipulation are sensed through the senory organs of touch which are fiee nei ve endings with high densities at the fingers and low densities at the palm and all ovei the human body. The role of these mechanoreceptors is not yet completeK undeistood however, some conclusions can be drawn from neurophysioiogical experiments which include the measurement of the response of such receptois dunng the execution of manipulation tasks. For example, from these experiments we conclude that human sense of touch has vibration sensors. These vibrations ai e genei ated in many instances duπng manipulation. An event whei e vibi ations ai e generated is contact with an object and of course another is the puncture of tissue. DESCRIPTION OF THE INVENTION With the piesent mvention we desire to offer information to the surgeon dunng the puncture with the punctuπng needle. This puncture in order to be successful should go through the hypodermic fat, the transversahs fascia, the exti apeπtonial fat and the peritoneum ( the skm is cut before puncture). If we view this task in tei ms ol human manipulation according to the proceeding analysis in important task parameters we will observe that it consists of a series of events and phases. The process of puncture mcludes the puncture of hard tissues and the peneti ation in soft fatty tissues. In this particular case punctures are the events and penetrations ai e the phases If we could measure the force on the puncturing needle we would see m force until the puncture of tissue. At the instance of punctuie this foi ce would increase and decrease generating therefore fast transient vibi ations. Duπng the penetration through the fatty tissue the force would remain almost constant The next stages would have similar progress As we have already mentioned these vibi ations generated by punctures are sensed by touch vibrations sensors. Industrial application of the invention One preferred realisation of the invention includes initially the needle. A sensor capable of sensing vibrations can be placed on any location as long as it is coupled to the needle. There is also means for insulating the sensor from external thermal and/or mechanical influense. This way the vibrations during puncture will be measured. The signal produced by the sensor is amplified by an amplifier which can be a charge amplifier for piezoelecrtic sensors. Initially the puncture information is relayed to the user of the system via a visual monitor such as an oscilloscope. By monitoring this signal we could diagnose and code successfully the precise time succession of phases and events of the puncture of tissues and penetration of fat and consequently the successful total puncture with the needle. The puncture information could be also relayed with audio or haptic means too. More specifically with the realization of this system we would observe in the initial puncture in laparoscopic surgery that the signal of the sensor would differ during penetration of fat and puncture of tissue and this would be indicative of succesfull puncture. We could exploit the fact that the mechanical characteristics of human tissue do not differ by much (from an engineering point of view) in other words the mechanical interaction between the surgical tool and tissues would generate vibrations in a restricted frequency spectrum. Therefore we could add a band pass filter to filter out the frequencies that are not relevant to the tasks. The diagnosis of the puncture would be much easier. In the system already described we can add a processing stage that contains a computer with I/O capabilities that can communicate with the sensor system. The processed system can be fed to some device that will relay the desired information to the surgeon. As we have already mentioned we could exploit the restricted frequency spectra that the punctures will produce. We could therefore create a database where we could add puncturing measurement to after each operation. We could also create this database from mechanical models. Having this database we could add an indication for the surgeon through which we could inform him/her of the probability of successful puncture. In other words we could compare the values of vibration that are measured during the puncture to values from the database and conclude from this comparison the probability of successful puncture. With the use of a computer we could transform the sensor signal in various ways and present it to the surgeon through different displays. It could be a visual display : e.g. colour, leds, graphs etc. It could also bean audio display e.g. tone or volume. Finally it could be a haptic display that directly stimulates the sense of touch. All of these option and experimentation are possible with a processing stage such as a computer. All of the above mentioned displays (haptic, audio, visual) could be used without the use of a computer or any processing stage if processing of the signal is not needed. An example of a measurement and relay system of (puncturing) information during laparoscopic and. in general, surgical operations will be described with reference to the attached drawings after a brief description of these drawings: Figure 1 shows events and phases in manipulation; Figure 2 shows events and phases during punctuπng task; Figure 3 shows an initial stage of realization of the invention; Figure 4 shows the addition of a bandpass filter to the system; Figure 5 shows the addition of a computer to the system as well as the different presentations to the user that are possible with the use of such a processing stage. Manipulation consists of a series of events and phases. Phases are simple subtasks ol human manipulation whose boundaries are defined by the events. Events ai e the indications of the status of human manipulation and help in the serial coordination of activities for the successful completion of a task. For example, the instance ol contact of the fingers with an object is the event of contact (Figure 1). When this event is detected from the subject that performs a certain task the subsequent activities are coordinated in such a way so as to lead to the successful lift of the object (if for example the desired task is to grasp and lift the object). These subsequent activities include the increase of the load force and the lift of the object With the present invention we desire to offer information to the surgeon dunng the puncture with the puncturing needle. This puncture in order to be successful should go through the hypodermic fat, the transversalis fascia, the extrapeπtonial fat and the peritoneum (the skin is cut before puncture_see also Figure 2). If we view this task in terms of human manipulation according to the proceeding analysis in important task parameters we will observe that it consists of a series of events and phases. The process of puncture includes the puncture of hard tissues and the peneti ation in soft fatty tissues". In this particular case punctures are the events and penetrations ai e the phases. If we could measure the force on the puncturing needle we would see in force until the puncture of tissue. At the instance of puncture this force would increase and decrease generating therefore fast transient vibrations. During the penetration through the fatty tissue the force would remain almost constant. The next stages would have similar progress as we can see in Figure 2. One preferred realisation of the invention is shown in Figure 3 and it includes initially the needle 1. A sensor 3 capable of sensing vibrations can be placed on am location as long as it is coupled to the needle. There is also means 2 for insulating the sensor from external thermal and/or mechanical influense. This way the vibrations dunng puncture will be measured. The signal produced by the sensor is amplified b\ an amplifier 4 which can be a charge amplifier for piezoelecrtic sensors. Initially the puncture information is relayed to the user of the system via a visual monitoi such as an oscilloscope 5. We could exploit the fact that the mechanical characteristics of human tissue do not differ by much (from an engineering point of view) in other woids the mechanical interaction between the surgical tool and tissues would generate vibrations in a restricted frequency spectrum. Therefore we could add as we can see in Figure 4 a bandpass filter 6 to filter out the frequencies that are not relevant to the tasks. The diagnosis of the puncture would be much easier. In the system shown in Figures 3 and 4 we can add a processing stage that contains a computer 8 with 1/0 capabilities (such as an A/D 7 and a D/A 9 card) that can communicate with the sensor system as shown in Figure 5. The processed signal can be fed to some device that will relay the desired information to the surgeon. With the use of a computer we could transform the sensor signal in various ways and pi esent it to the surgeon through different displays. It could be a visual display 10a : e.g colour, leds. graphs etc. It could also be an audio display 10b e.g. tone or volume Finally it could be a haptic display 1 Oc that directly stimulates the sense of touch . All of these options and experimentation are possible with a processing stage such as a computer. All of the above mentioned displays (haptic, audio, visual) could be used without the use of a computer or any processing stage if processing of the signal is not needed.

Claims: CLAIMS 1. Measurement and relay system of (puncturing) information dunng lapai oscopic and, in general, surgical operations comprismg of a system of sensors ( vibration displacement or pressure) coupled to the puncturing tool ( e.g. Veress needle ) a processing stage and a display system of information which (the whole system) is the technical realization of measurement of features of taxonomy of events and phases ol human manipulation. This technical realization is especially adapted in the puncturing and manipulation of human tissue and other similar materials in a similai manner as the use of these features in human manipulation during manipulation tasks. 2. Measurement and relay system of (puncturing) information duπng laparoscopic and, m general, surgical operations as described in count 1 where in the said system sensor's signal differs at the puncturing instance from the signal during the penetration in softer fat tissue. 3. Measurement and relay system of (puncturing) information during laparoscopic and, in general, surgical operations as described in count 1 and 2 where in the said display system is haptic, audio and or visual. 4. Measurement and relay system of (puncturing) information during laparoscopic and, in general, surgical operations as described in count 1 , 2 and 3 where in the said system the sensor is coupled to any part of the puncturing tool in order to measui c vibration during the attempted surgical puncturing of tissue and othei similai material. 5. Measurement and relay system of (punctuπng) information duπng laparoscopic and. in general, surgical operations as described in count 1 , 2 and 3 whei e in a bandpass filter is added that filter out the irrelevant frequencies and leaves the relevant to the puncturing frequencies to pass so that the detection of punctuπng is easier and safer. 6. Measurement and relay system of (puncturing) information duπng lapai oscopic and, in general, surgical operations as described in count 1 , 2 and 3 whei e in a processing stage (computer) is added with 1/0 cards and communicate with the sensor system so that the processed signal could he relayed to the user ' s display to provide information relevant to the puncture according to count 3. 7. System of sensor according to counts 1 ,2 and 3 that attaches to the punctuπng tool and measure and relays information for the exact position of the punctunng tool in the human body. 8. Measuiement and relay system of (puncturing) information during lapai oscopic and, in general, surgical operations as described in count 1 , 2 and 3 that comprises ol the said system of sensors capable of detecting the end of contact with the punctui ed tissue.

Inventors: KONTARINIS DIMITRIOS, KONTARINIS, DIMITRIOS
Applicants: KONTARINIS DIMITRIOS, KONTARINIS, DIMITRIOS
Application year: 1997
Main classification: A61B5
IPC codes: A61B5, A61B17, A61B19