Abstract: The present disclosure relates to a method, a system, and a storage medium for segmenting a lung image. The method for segmenting a lung image comprises: obtaining medical image data containing a lung region; performing lung lobe segmentation on the medical image data to generate a plurality of lung lobe data subsets; generating updated lung image data based on one or a plurality of lung lobe data subsets in the plurality of lung lobe data subsets; and performing nidus segmentation on the updated lung image data to generate a segmentation image that identifies a pneumonia nidus.

Abstract: A method for in-vivo monitoring of a target internal volume of a mammal that includes: (a) placing the target internal volume proximal to a three-dimensional magnetic field generator; (b) generating first, second, and third magnetic field gradients along respective first, second, and third axes that are mutually orthogonal; (c) measuring first, second, and third magnetic fields with a three-dimensional magnetic sensor disposed in an ingestible capsule, the ingestible capsule disposed in the target internal volume; (d) with a controller in electrical communication with the three-dimensional magnetic sensor, generating a magnetic sensor output signal that encodes a measurement of the first, second, and third magnetic fields; (e) broadcasting the magnetic sensor output signal from an antenna disposed in the ingestible capsule, and (f) receiving the magnetic sensor output signal with a receiver. The received magnetic field data can be used to determine the three-dimensional position of the ingestible capsule.

Abstract: An endoscope adaptor according to an embodiment may include a base portion including a transmission mechanism configured to decelerate and transmit rotation of a driven member configured to be driven to rotate by a drive part of a robot arm to an endoscope holder. The transmission mechanism includes a drive transmission shaft that is configured to be rotated by the rotation of the driven member, a first linkage member that is configured to rotate integrally with the drive transmission shaft, and a second linkage member being rotatable with respect to the drive transmission shaft and configured to rotate with first linkage member in a linked manner. The base portion includes a stopper configured to come in contact with the second linkage member to stop rotation of the drive transmission shaft.

Abstract: An endoscope adaptor according to an embodiment may include: an endoscope holder configured to hold an endoscope to be rotatable; and a base portion including an attachment portion, a driven member, and a transmission mechanism. The base portion includes a cable holder configured to hold a cable connected to the endoscope.

Abstract: A disclosed apparatus may include (1) a power enclosure electrically coupled to a power supply module of a computing device, (2) a power connector that (A) is electrically coupled to a power cable that facilitates carrying electric current to the power supply module via the power enclosure and (B) is dimensioned to mate with the power enclosure, and (3) at least one power switch that (A) is electrically coupled to the power enclosure, (B) is configured to be engaged by at least one feature of the power connector while the power connector is fully mated with the power enclosure, and when engaged by the feature of the power connector, (C) enables electric current to flow from the power connector to the power supply module via the power enclosure. Various other apparatuses, systems, and methods are also disclosed.

Abstract: An electromagnetic (EM) system for tracking a surgical tool is provided. The system may comprise a plurality of subsets of field generator coils disposed along edge portions of a surgical bed. Each subset of field generator coils may be configured to generate a magnetic field within a control volume. The system may further comprise a position sensor disposed on a portion of the surgical tool. The position sensor may be configured to generate a sensor signal in response to the magnetic field when the position sensor is located inside the control volume. Additionally, the system may comprise an EM system controller configured to selectively activate one or more of the subsets of field generator coils based on the sensor signal.

Abstract: Systems and methods for performing concomitant medical procedures are disclosed. In one aspect, the method involves controlling a first robotic arm to insert a first medical instrument through a first opening of a patient and controlling a second robotic arm to insert a second medical instrument through a second opening of the patient. The first robotic arm and the second robotic arm are part of a first platform and the first opening and the second opening are positioned at two different anatomical regions of the patient.

Abstract: A non-transitory machine-readable media storing instructions is provided. The instructions cause one or more processors to: define a subregion of a model of an anatomic region of a patient anatomy, the subregion corresponding to an area surrounding a tip of an image capture probe located within the anatomic region, the subregion including a plurality of virtual tissue structures—a set of virtual tissue structures of the plurality of virtual tissue structures is situated distally from the tip of the probe; compare a tissue structure in an image received from a camera positioned at the tip of the probe to a portion of the plurality of virtual tissue structures to identify a closest matched virtual tissue structure; and based on identification of the closest matched virtual tissue structure, register the image to the model to identify a virtual probe position for the tip of the probe with respect to the model.

Abstract: A method can include receiving image data characterizing a viewed object acquired via an image sensor of a visual inspection system and providing the image data in a display. The method can include receiving a first directional movement input via a directional input device of the visual inspection system and applying a first set of actuator drive signals to a plurality of actuators of the visual inspection system. The method can further include applying a coordinate transformation to the image data to generate transformed image data and receiving a second directional movement input via the directional input device. The method can also include applying a second set of actuator drive signals to the plurality of actuators. The second set of actuator drive signals can cause points on the viewed object to move in the first direction on the display. Related systems performing the method are also provided.

Abstract: A processing system (100, 200) for processing surgical images. The system includes at least one image pickup unit (115) for obtaining surgical image frames and data, at least one image receptor (113) for receiving surgical image frames to be displayed, and a processing unit (153) connected with a network (103, 106, 107) to the image pickup unit (115) for receiving surgical image frames, the processing unit (153) being configured for processing the surgical image frames and for extracting at least one processing information thereof. The processing unit further is being connected to the at least one image receptor (113) for providing the at least one correction parameter to the at least one image receptor. The system further comprises a connection (102) between the at least one image pickup unit (115) and the image receptor (113), for sending the surgical image frames directly to the image receptor (113).

Abstract: A calibration assembly may be used with an endoscopic imaging system having a field of view. The calibration assembly may comprise an interface configured for constraining engagement with the endoscopic imaging system and a target coupled with the interface so as to be within the field of view. The target may include a plurality of calibration features. The calibration assembly may be reconfigurable from a first spatial arrangement between the target and the endoscopic imaging system to a second spatial arrangement between the target and the endoscopic imaging system. The calibration assembly may also comprise a processor configured to obtain, from the endoscopic imaging system, first and second images of at least some of the calibration features of the target at the first and second spatial arrangements. The processor may also generate calibration data for the endoscopic imaging system using the first and second images.

Abstract: Systems and methods are described herein that improve control of a shapeable or steerable instrument using shape data. Additional methods include preparing a robotic medical system for use with a shapeable instrument and controlling advancement of a shapeable medical device within an anatomic path. Also described herein are methods for altering a data model of an anatomical region.

Abstract: The present disclosure pertains to an apparatus and methods of an imaging device for obtaining images from the walls of luminal organs or a surgical cavity. The device is capable of passage through luminal organs or introduction into surgical cavities, and obtains images by rapidly scanning a focused light beam on the tissue to be imaged and receiving light from the tissue. The device comprises at least one mechanism for projecting a 2-dimensional (2-D) optical pattern, such as a 2-D scanner (508) or a 2-D optical array forming a closed loop scan pattern (506). The device comprises at least one other beam scanning mechanism, such as a rotary or angular scanner (510) such that cycloid scan pattern is formed on the surface to be scanned, and also has embodiments of focusing optics at different regimes of numerical aperture. The disclosure also describes methods for accurate image reconstruction with embodiments of hardware control and post-acquisition processing.

Abstract: A method for displaying guidance information during an image-guided medical procedure includes receiving, by one or more hardware processors, data from a tracking system associated with an elongate device comprising a flexible body, calculating a bend radius along a length of the flexible body, determining supplemental guidance information that includes an indication of whether the bend radius is less than a minimum allowable bend radius, augmenting images with the supplemental guidance information to produce augmented images by applying a scheme in which a portion of a graphical representation of the flexible body having a radius less than the minimum is augmented with a visual property, displaying the augmented images on a display device at a console, determining a direction to steer the flexible body to increase the bend radius, and displaying actuation information on the display device. The actuation information includes a directional indicator to display the direction.

Abstract: A remote workstation for the control of percutaneous intervention devices is provided. The remote workstation includes a control system for remotely and independently controlling at least two percutaneous intervention devices. The control system includes at least one input device to control the percutaneous intervention devices. The control system controls movement of at least one of the percutaneous intervention devices along at least two degrees of freedom. The remote workstation also includes a graphical user interface for displaying icons representative of the operational status of each of the percutaneous intervention devices.

Abstract: Methods of producing augmented probe system images and associated probe systems. A method of producing an augmented probe system image includes recording a base probe system image, generating the augmented probe system image at least partially based on the base probe system image, and presenting the augmented probe system image. The augmented probe system image includes a representation of at least a portion of the probe system that is obscured in the base probe system image. In some examples, a probe system includes a chuck, a probe assembly, an imaging device, and a controller programmed to perform methods disclosed herein.

Abstract: An endoscopy system including a flexible insertion tube, a motion sensing module and a processor is provided. The flexible insertion tube has a central axis. The motion sensing module includes a housing, patterns and sensors. The patterns are disposed at a surface of the flexible insertion tube according to an axial orientation distribution and an angle distribution based on the central axis. The sensors are disposed in the housing and located beside a guiding hole of the housing. The processor is disposed in the housing. During relative motion of the flexible insertion tube with respect to the motion sensing module via the guiding hole, the sensors are configured to sense a motion state of the patterns so as to obtain a motion-state sensing result. The processor determines insertion depth information and insertion tube rotating angle information according to the motion-state sensing result, the axial orientation distribution and the angle distribution.

Abstract: A method of controlling movement of the tip of a surgical endoscope from a first position (E) to an intermediate position (E?), the field of view from the tip of the endoscope being at an angle (?) relative to a longitudinal shaft of the endoscope, the method comprising: receiving a command to move from the first position in a first direction; identifying a nominal view point (N) from the tip of the endoscope in the first position; calculating a tip movement path from the first position based on the received command, the identified nominal view point and the angle (?); determining the intermediate position; and moving the tip to the intermediate position, the intermediate position being such that the nominal view point remains within the field of view from the tip.

Abstract: A surgical system includes a sensor positionable in an operating room and configured to detect a position of an object in the operating room. The surgical system also includes a controller configured to assign a desired time milestone for each step of a surgical workflow, automatically distinguish the steps of the surgical workflow based on a change in the position of the object, based on distinguishing the steps of the surgical workflow, record a comparison of an actual timing of each step of the surgical workflow with the desired time milestone for each step of the surgical workflow, and generate feedback relating to usage of the operating room based on the comparison.

Abstract: A system for use in surgery includes a central body, a visualization system operably connected to the central body, a video rendering system, a head-mounted display for displaying images from the video rendering system, a sensor system, and a robotic device operably connected to the central body. The visualization system includes at least one camera and a pan system and/or a tilt system. The sensor system tracks the position and/or orientation in space of the head-mounted display relative to a reference point. The pan system and/or the tilt system are configured to adjust the field of view of the camera in response to information from the sensor system about changes in at least one of position and orientation in space of the head-mounted display relative to the reference point.

Abstract: A method is disclosed for diagnosing and treating a patient having lesions in both arteries of left and right lower limbs. By determining that a lesion distal to an aortailiac bifurcation is to be treated first, catheters and an operation time can be reduced is to be treated first on a priority basis based on diagnostic data, deciding that a lesion proximal to the bifurcation is to be treated next, then treating the lesions substantially continuously.

Abstract: A method for removing a tissue lesion where an anchor is established with the lesion. A channel is created in the tissue leading to the anchored lesion. A tissue core is created which includes the lesion. The tissue core is ligated, amputated and removed from the channel.

Abstract: Systems, devices, and methods for determining advancement of a surgical laser fiber in an endoscope and providing interlocking feedback for the surgical laser are disclosed. An exemplary method includes directing light from a distal end of an endoscope to a target, optically detecting an amount of the light reflected from the target, transmitting the optically detected amount of light through a laser fiber extending through a working channel of the endoscope, determining, based on the optically detected amount of light, a position of a distal end of the laser fiber relative to the distal end of the endoscope, and generating a control signal to the surgical laser system to adjust laser emission through the laser fiber.

Abstract: In order to reduce costs for endoscopic examinations and to enable new operating concepts, an image recording arrangement is provided in which an adapter that enables bi-directional communication between a camera control unit and an image generation unit which has an image sensor. A standardized data interface is configured between the camera control unit and the adapter. The adapter is defined for use with a specific type of image generation unit. Accordingly, the adapter has a communication apparatus which translates control and adjustment commands transmitted by the camera control unit into a format processable by the image generation unit and provides image data from the image sensor in a format processable by the camera control unit.

Abstract: The invention relates to a method of simultaneously calibrating magnetic actuation and sensing systems for a workspace, wherein the actuation system comprises a plurality of magnetic actuators and the sensing system comprises a plurality of magnetic sensors, wherein all the measured data is fed into a calibration model, wherein the calibration model is based on a sensor measurement model and a magnetic actuation model, and wherein a solution of the model parameters is found via a numerical solver order to calibrate both the actuation and sensing systems at the same time.

Abstract: A robotic system includes an electrosurgical generator; an electrosurgical instrument including an electrosurgical connector; and a robotic arm having an instrument drive unit coupled to the electrosurgical instrument. The instrument drive unit includes a drive unit housing having: an electrosurgical receptacle coupled to the electrosurgical generator and configured to engage the electrosurgical connector; an activation link configured to engage the electrosurgical connector; and a detection switch actuatable by the actuation link upon being engaged by the electrosurgical connector.

Abstract: A magnetic distribution detection method includes the steps of providing a magnetic sensor and a sample, selecting a multiple of measuring points on the sample, sensing the measuring points by the magnetic sensor, obtaining a multiple of sense data and a series of the heights of the magnetic sensor from each measuring point, using a signal decomposition algorithm to convert these sense data into data groups, and selecting one of the data groups as the magnetic distribution data of the sample.

Abstract: Proposed is a mechanism capable of securing both convenience and safety in regard to surgery performed by inserting an endoscope into a human body. A medical arm system including a multi-joint arm which has a plurality of links connected by joints and a distal end to which an endoscope is connectable and a control unit which sets a virtual plane in a body cavity of a patient and controls the multi-joint arm so as to constrain a predetermined point of the endoscope in the body cavity on the virtual plane.

Abstract: An enhanced flexible robotic endoscopy apparatus includes a main body and flexible elongate shaft. The main body comprises a proximal end, a distal end and a housing that extends to the proximal end and the housing comprises a plurality of surfaces and a plurality of insertion inlets which reside on at least one of the surface of the housing at the proximal end of the main body, through which a plurality of channels for endoscopy are accessible. Each of the insertion inlets has insertion axis corresponding thereto, along which flexible elongate assemblies are insertable, with the insertion axes of the insertion inlets being parallel to the central axis of the flexible elongate shaft at the proximal end of the flexible elongate shaft.

Abstract: A system includes an expandable distal-end assembly, a proximal position sensor, a distal position sensor, and a processor. The expandable distal-end assembly is coupled to a distal end of a shaft for insertion into a cavity of an organ of a patient. The proximal and distal position sensors are located at a proximal end and a distal end of the distal-end assembly, respectively. The processor is configured to estimate a position and a longitudinal direction of the proximal sensor, and a position of the distal sensor, all in a coordinate system used by the processor. The processor is further configured to project the estimated position of the distal sensor on an axis defined by the estimated longitudinal direction, and calculate an elongation of the distal-end assembly by calculating a distance between the estimated position of the proximal sensor and the projected position of the distal sensor.

Abstract: A lesion detection system for use with a patient, comprising an optoacoustic guide wire assembly configured to be insertable into a patient's tissue. The optical acoustic guide wire assembly can be comprised of an optical waveguide have a first end and a second end, a light source coupled to the second end of the optical waveguide, wherein said light source configured to emit energy to the patient's tissue, at least one transducer configured to detect an ultrasound signal emitted from the patient's tissue in response to energy emitted from the light source, and a computer system.

Abstract: The present disclosure relates to a method for analyzing an electrode for a battery, which has the advantage of being capable of more easily distinguishing between the constituent materials of the electrode such as the electrode active material, the conductive material, and the pores, by using scanning spreading resistance microscopy.

Abstract: An imaging condition set in a first region of a three-dimensional model of a subject and an imaging condition set in a second region of the three-dimensional model are different from each other. A processor of an observation device determines whether or not the imaging condition that has been set in the first region or the second region including a position on the three-dimensional model is satisfied. The position is identified on the basis of a position of an imaging device and a posture of the imaging device. The processor displays observation information on a display on the basis of a result of determination. The observation information represents whether or not the first region or the second region including the position on the three-dimensional model has been observed.

Abstract: A medical system may comprise a display and a processor configured to determine an optimal position for an image capturing instrument to view working ends of a plurality of medical instruments when the plurality of medical instruments and the image capturing instrument are each extending out of a distal end of an entry guide. The processor may also be configured to cause the optimal position to be displayed on the display along with an image captured by the image capturing instrument of the working ends of the plurality of medical instruments.

Abstract: A medical system includes an instrument, a display system, and a processing unit. The instrument includes an instrument shape sensor. The processing unit includes one or more processors. The processing unit is configured to, receive an anatomic model of a patient anatomy, receive shape sensor data from the instrument shape sensor while the instrument is positioned within the patient anatomy and registered to the anatomic model, determine a preferred fluoroscopic image plane for display on the display system based on the received shape sensor data and the area of interest, and provide an indication on the display system to guide positioning of a fluoroscopy system to obtain a fluoroscopic image in the preferred fluoroscopic image plane. An area of interest is identified in the anatomic model.

Abstract: An electronic device is disclosed. The electronic device comprise an elongate electrical connector that is configured to connect to an integrated device package. The elongate electrical connector can comprise an elongate flexible substrate. The elongate flexible substrate has a proximal portion and a distal portion spaced from the proximal portion by a length along a longitudinal axis. The elongate flexible substrate has a width along an axis transverse to the longitudinal axis. The elongate flexible substrate defines an elongation ratio of the length to the width. The elongation ratio is at least 100:1. The elongate electrical connector can be connected to a bobbin. The elongate electrical connector can be configured to unspool from the bobbin.

Abstract: In some embodiments, an apparatus can include a robotic arm cart for transporting, delivering, and securing robotic arms to a surgical table having a table top on which a patient can be disposed. The arm cart can include an arm container and a base. The arm container can be configured to receive and contain one or more robotic arms. The arm cart can include a first coupling member configured to engage with a second coupling member associated with a surgical table such that, when the first coupling member is engaged with the second coupling member, the one or more robotic arms can be releasably coupled with the surgical table. The arm cart can provide for movement of the one or more robotic arms in at least one of a lateral, longitudinal, or vertical direction relative to the table top prior to the securement of the one or more robotic arms to the surgical table.

Abstract: Certain aspects relate to systems and techniques for optical strain sensing in medical instruments. In one aspect, a medical instrument includes an elongated shaft, and at least one pull wire extending from a proximal end of the elongated shaft to the distal end of the elongated shaft. The at least one pull wire is configured to cause actuation of the medical instrument in at least one degree of freedom. The at least one pull wire includes an optical fiber configured to provide an indication of strain along the at least one pull wire.

Abstract: A method for displaying guidance information using a graphical user interface during an medical procedure comprises displaying, in a first mode of the graphical user interface, first image data from a perspective corresponding to a distal end of an elongate device. The first image data includes a virtual roadmap. The method also comprises transitioning from the first mode of the graphical user interface to a second mode of the graphical user interface. The transition is based on an occurrence of a triggering condition. The method also comprises displaying, in the second mode of the graphical user interface, second image data from a perspective corresponding to the distal end of the elongate device. The second image data includes a target indicator corresponding to a target location and an alignment indicator corresponding to an expected location of the medical procedure at the target location.

Abstract: In one embodiment, an apparatus includes a medical instrument, a position tracking system to track coordinates of the instrument within a passage in a body, a processor to register the system and a 3D CT image of at least a part of the body, find a path of the instrument through the passage, compute segments of the path, compute respective locations along the path of respective virtual cameras responsively to the computed segments, select the respective virtual cameras for rendering respective virtual endoscopic images responsively to the tracked coordinates, compute respective orientations of the respective virtual cameras, and render and display the respective virtual endoscopic images, based on the 3D CT image, of the passage in the body viewed from the respective locations and orientations of the respective virtual cameras including an animated representation of the instrument positioned in the respective virtual endoscopic images in accordance with the tracked coordinates.

Abstract: The present invention relates to a system and a method for calibration between coordinate systems of a 3D camera and a medical imaging apparatus and an application thereof.

Abstract: Offset illumination using multiple emitters in a fluorescence imaging system is described. A system includes an emitter for emitting pulses of electromagnetic radiation and an image sensor comprising a pixel array for sensing reflected electromagnetic radiation. The emitter comprises a first emitter and a second emitter for emitting different wavelengths of electromagnetic radiation. The system is such that at least a portion of the pulses of electromagnetic radiation emitted by the emitter comprises a laser mapping pattern.

Abstract: A method comprises obtaining an endoscopic image dataset of a patient anatomy from an endoscopic imaging system and retrieving an anatomic model dataset of the patient anatomy obtained by an anatomic imaging system. The method also comprises mapping the endoscopic image dataset to the anatomic model dataset and displaying a first vantage point image using the mapped endoscopic image dataset. The first vantage point image is presented from a first vantage point at a distal end of the endoscopic imaging system. The method also comprises displaying a second vantage point image using at least a portion of the mapped endoscopic image dataset. The second vantage point image is presented from a second vantage point, different from the first vantage point.

Abstract: A removal tool for removing a hood having a hollow cylindrical shape mounted to a distal tip of an endoscope from the distal tip is constituted from a flexible member including a hole-shaped recess capable of housing the hood in its inside. An outer surface of the hood is provided with a step portion that extends along a circumferential direction of the hood. An inner wall surface of the recess is provided with an engaging portion at a position opposing to the step portion when the hood is housed in the recess, the engaging portion being shaped to grip the hood by being engaged with the step portion as a result of deformation of the flexible member.

Abstract: A minimally invasive system comprises an elongate medical instrument including a flexible body. The flexible body includes a wall including a channel, and the channel includes a groove. The flexible body further includes a lumen defined by an interior surface of the wall and a curved distal tip portion. The elongate medical instrument further includes a shape sensor coupled to the flexible body. The shape sensor is at least partially positioned within the groove, and the shape sensor is configured to detect shape characteristics of at least a portion of the flexible body. The system further includes an actuator for manipulating the elongate medical instrument.

Abstract: Provided are systems and methods for registration of location sensors. In one aspect, a system includes an instrument and a processor configured to provide a first set of commands to drive the instrument along a first branch of the luminal network, the first branch being outside a path to a target within a model. The processor is also configured to track a set of one or more registration parameters during the driving of the instrument along the first branch and determine that the set of registration parameters satisfy a registration criterion. The processor is further configured to determine a registration between a location sensor coordinate system and a model coordinate system based on location data received from a set of location sensors during the driving of the instrument along the first branch and a second branch.

Abstract: A system and method of planning a procedure includes a planning workstation including: a display system; and a user input device. The planning workstation is configured to: display image data via the display system; receive a first user input via the user input device; display via the display system a target of a medical procedure within the displayed image data identified based at least on the first user input; display an interactive image via the display system, the interactive image including the image data, a plurality of connected anatomical passageways, and the identified target; receive a second user input via the user input device; display via the display system a trajectory between the target and an exit point along a nearest passageway of the plurality of connected anatomical passageways identified based at least on the second user input; receive a third user input via the user input device; and adjust the interactive image based at least on the defined trajectory and the third user input.

Abstract: Methods, systems, and devices for accessing tissue outside a bronchus and marking the location of a biopsy are provided. The method includes loading a navigation plan into a navigation system with the navigation plan including a CT volume generated from a plurality of CT images, inserting an extended working channel (EWC) including a location sensor into a patient's airways, registering a sensed location of the EWC with the CT volume of the navigation plan, and selecting a target in the navigation plan located outside the periphery of a patient's airways. The method further includes navigating the EWC and location sensor proximate the target, inserting a piercing catheter into the EWC, piercing through an airway wall to reach the target, storing a position of the location sensor in the navigation system as a biopsy location, and performing a biopsy at the stored biopsy location.

Abstract: A force estimation system for calculating force information regarding forces applied to one or more positions of a flexible tubular portion having flexibility through an arithmetic operation, the force estimation system comprising: a processor configured to input the deformation state and the mechanical property at a plurality of longitudinal positions of the flexible tubular portion, and calculates the force information of the force applied to the individual positions of the flexible tubular portion based on the deformed state and the mechanical property.

Abstract: There is provided herein an optical system for a tip section of a multi-sensor endoscope, the system comprising: a front-pointing camera sensor; a front objective lens system; a side-pointing camera sensor; and a side objective lens system, wherein at least one of said front and side objective lens systems comprises a front and a rear sub-systems separated by a stop diaphragm, said front sub-system comprises, in order from the object side, a first front negative lens and a second front positive lens, said rear sub-system comprises, in order from the object side, a first rear positive lens, an achromatic sub-assembly comprising a second rear positive lens and a third rear negative lens, wherein the following condition is satisfied: f(first rear positive lens)?1.8f, where f is the composite focal length of the total lens system and f(first rear positive lens) is the focal length of said first rear positive lens.