Localization of drilling tool position through bone tissue identification during surgical drilling

This paper proposes a detection method to identify the drill bit position during assisted bone drilling. A platform has been developed to support the surgeon in the planning of the drilling path. Albeit constrained along a fixed trajectory, the advancement of the drilling tool is manual, in order to preserve the natural haptic perception of the surgeon, who remains in charge of modulating the drilling force and the feeding rate according to the position of the drill bit in the bone. This paper describes a custom drill, embedded with force and position sensors, which allows the evaluation of a new parameter, referred to as Average Impedance (AI), that is related to the mechanical properties of the tissues in contact with the drill bit. An algorithm for layer identification has been implemented based on the variability of the AI signal. In perspective, the AI can provide the surgeon with additional information about the position of the drill bit in the bone, in order to increase the safety level of the procedure. The algorithm has been tested ex-vivo on swine bones. The tests demonstrated a reliability better than 80% in the discrimination of bone tissues.     

印制板用微型钻头及微孔钻削进展

尽管激光钻孔在印制板（PCB）钻孔中应用得越来越广,但是利用微型钻头在机械钻机上进行的机械钻孔仍然是最重要的PCB钻孔方式。顺应PCB微孔的发展趋势,微型钻头直径越来越小,新型钻头结构不断出现,微钻头性能不断提高,微钻头涂层技术逐步成熟,微孔钻削的研究不断深入,推动着PCB技术的发展。本文即对微钻头及微孔钻削的进展进行总结,对微钻头和微孔钻削的趋势进行展望。     

Precise robot-assisted guide positioning for distal locking of intramedullary nails

This paper presents a novel image-guided robot-based system to assist orthopedic surgeons in performing distal locking of long bone intramedullary nails. The system consists of a bone-mounted miniature robot fitted with a drill guide that provides rigid mechanical guidance for hand-held drilling of the distal screws' pilot holes. The robot is automatically positioned so that the drill guide and nail distal locking axes coincide, using a single fluoroscopic X-ray image. Since the robot is rigidly attached to the intramedullary nail or bone, no leg immobilization or real-time tracking is required. We describe the system and protocol and present a method for accurate and robust drill guide and nail hole localization and registration. The in vitro system accuracy experiments for fronto-parallel viewing show a mean angular error of 1.3 degrees (std = 0.4 degrees ) between the computed drill guide axes and the actual locking holes axes, and a mean 3.0 mm error (std = 1.1 mm) in the entry and exit drill point, which is adequate for successfully locking the nail.     

Control and breakthrough detection of a three-axis robotic bone drilling system

This paper describes a robotic bone drilling system for applications in orthopedic surgery. The goal is to realize a three-axis robotic drilling system which can automatically stop drilling at the moment a drill breaks through bone. The proposed robotic bone drilling system consists of an inner loop fuzzy controller for robot position control, and an outer loop PD controller for feed unit force control. Moreover, breakthrough detection is a function of thrust force threshold information and trends in drill torque and feed rate. The proposed technique has been verified by drilling pig bones, the results for both the bone drilling and bone breakthrough processes are in accord with theoretical model.     

The detection of drill bit break-through for the enhancement of safety in mechatronic assisted orthopaedic drilling

The present surgical drilling processes, which are performed manually, can greatly benefit from mechatronic assistance. Measurement of bone drilling force can contribute significantly towards the enhancement of safety through the detection of drill bit break-through in order to prevent excessive protrusion of the drill bit. This paper describes a reliable and repeatable method of break-through detection based on a modified Kalman filter when drilling into long bones. A control strategy for the break-through detection is also provided. By applying the modified Kalman filter to force difference between successive samples (FDSS), the imminent drill bit break-through can be detected using different threshold levels of Kalman filtered FDSS (K-FDSS) in the presence of system compliance and inherent drilling force fluctuation. In addition, the method of break-through detection can be applied to different drill bit types over a range of drilling conditions.     

一种新型的超声波/声波钻探器

提出了一种新型的超声波/声波钻探器,并对其进行了理论和实验研究.采用有限元法对钻探器的换能器部分和钻杆部分进行了模态分析和谐响应分析.设计并加工了一套钻探器,针对4种不同的材料进行了钻探实验.实验结果表明,3 min能将砖头钻孔深9 mm,孔的直径为Φ6 mm.     

印制电路孔金属化

印制电路是电子工业重要部件,印制电路金属化孔要有良好的机械韧性和导电性,孔金属化涉及生产全过程,特别是钻孔,活化,化学镀铜尤为重点,必须做到孔内无钻屑,胶体色活性好,化学镀铜层为红棕色,才能生产出高质量优孔的印制板。     

CO2激光钻孔工艺优化方法研究

介绍了一种用CO2激光钻机开铜窗及打盲孔的新工艺,通过变换CO2激光钻机光束直径大小,达到CO2激光钻机开大窗,打小孔,从而控制孔型的目的。此新工艺可减少普通Cu—Direct工艺悬铜过大问题,也可避免干膜蚀刻开铜窗流程长,成本高等问题,针对激光孔孔底开裂失效缺陷也有所改善。     

背钻孔内披锋改善分析研究

背钻技术在高频电路板上运用越来越广泛,但背钻技术在加工过程中出现孔内披锋频繁,严重影响产品信号传输,在下游的SMT厂家焊接过程中,容易出现焊接不牢、虚焊、短路等问题。文章主要针对背钻加工出现孔内披锋的研究,通过实验分析找出背钻孔内披锋产生的原因,并且有针对性的对加工参数、钻头选择等方面对背钻孔内披锋改善的影响度研究;发现加工参数和钻头选择为孔内披锋产生的重要原因,通过实验优化背钻加工工艺参数,能够明显改善背钻孔内披锋。     

Design of a robotic orbital driller for assembling aircraft structures

Orbital drilling is a machining process designed to drill holes with a double circular motion, added by a linear displacement in the direction of drilling. A cutting tool is rotating at high speed in an eccentric orbit and simultaneously moves towards the surface of the material to be drilled. The adjustable eccentricity plus the diameter of the tool defines the final diameter of the hole. Orbital drilling is a fatigueless process with good surface finish and burr-free when compared with conventional drilling processes. To implement this process, an automatic orbital drilling device has been designed and built as an end-effector of an industrial robot. The process of developing this device, its requirements, functions and tests are detailed in this paper, resulting in the construction of the EFORB (an acronym in Portuguese of Robotic Orbital Drilling End-effector). This paper presents the latest results with the final version of the system, including the development’s integration with an industrial anthropomorphic robot. The results achieved show that the process requirements and tolerances are suitable for aeronautic applications.     

420μm以上超厚铜线路板钻孔加工技术研究

随着全世界汽车工业的快速发展,汽车用厚铜电源板的需求正呈现快速增长趋势,这就要求有能力生产厚铜电源板的厂家尽力寻求效率最高、质量最好的加工方法。然而众所周知,由于厚铜电源板铜箔太厚(普通板铜厚的5～12倍),在钻孔过程中会产生大量长度超过20000μm的钻屑,因此经常出现铜屑堵孔、堵塞机床真空管路、断刀、钻孔毛刺大、孔边铜箔突起、孔壁粗糙度大、孔位偏差大等严重影响产品质量与加工效率的问题,这些问题虽然通过降低叠层、增加跨孔停顿时间可以获得相对缓解,但却因此损失了较大的产能。随着线路板行业利润率越来越低、各企业都在研究各种先进工艺以提高生产效率并获取利润率的今天,这种低效率是不能忍受的。弊司在普通(120～160)krpm数控钻床上,运用独自研发的特殊断屑工艺、最佳的钻削参数以及对刀具的合理控制与研究,成功解决了钻屑堵孔及堵塞真空管路的问题,从而使钻孔过程中存在的其它一系列问题迎刃而解,真正实现了420μm以上超厚铜线路板的高速钻削。本文主要着眼于钻孔量产时的几个关健点,即钻削抗力、钻削参数、刀具控制进行技术分析评价。     

A Self-Optimizing Control System for Hard Rock Percussive Drilling

The derivation and application of a self-optimizing control system for percussive drilling of hard rock is presented. The control system superimposes an oscillating force signal onto the drill feed force and demodulates the signal from the drill rotational torque. The resultant demodulated signal is then used to control the drill, allowing real-time maximization of penetration rate, minimum hole deviation, and measurement of rock characteristics regardless of drilling conditions. The control system allows the drill to adapt to changing rock conditions. Testing has proven the control to be reliable and to increase drilling efficiency.     

印制板偏孔的影响因素及机理分析

钻孔工艺是印制板制造技术中最为重要的工序之一。然而针对该工艺的品质保证绝非易事。钻孔工艺受钻头、设备等的影响,在品质上容易出现偏孔等不良问题。本文通过单因素分析法,对印制板钻偏孔问题进行了分析,并探讨了各因素导致偏孔的机理。结果表明:孔位精度随着钻孔孔限的增加而减小;对钻孔时孔位精度影响较大的因素,依次为钻头品质、叠板数以及钻头翻磨次数。针对此试验结果,本文提出了相应的改善措施。     

PCB微钻有限元分析的几个关键问题

随着印制板和封装技术的快速发展,印制板钻孔面临越来越大的挑战。钻孔质量受钻机、钻头、钻削参数和印制板材的影响,文章对微钻有限元分析的几个关键问题进行探讨,以提高微钻设计水平。首先评述了微钻有限元分析的研究现状,然后讨论了微钻三维模型的建模方法,最后对微钻设计中的几个重要参数对微钻性能的影响进行了重点分析。文章的主要创新点包括:(1)提出了通过CAD方法建立微钻三维模型的方法,保证了有限元分析的精度;(2)分析了微钻参数对微钻性能的影响,该结果可以指导实际的微钻设计。     

DRIBON: A mechatronic bone drilling tool

This paper presents a new automatic mechatronic tool for bone drilling, a procedure which is currently very manual and where depth control is critical in most scenarios. The system and methods developed involve driving a rotating drill bit in an axial direction so that both the linear movement and the rotation of the drill bit are controlled and measurable for automatic drilling procedures. Control algorithms allow the system to effectively stop the drilling procedure as a response to bone layer transitions and/or breakthroughs without damaging the surrounding tissue. Validation experiments on the new bone drilling methodology and proposed system have been carried out.     

制孔工艺对激光强化前后小孔疲劳寿命的影响

在交变载荷作用下,小孔构件易产生疲劳裂纹,零件的使用寿命因此降低。为了研究制孔工艺对激光冲击强化前后小孔疲劳寿命的影响,文中选用材料为铝合金7050-T7451的双联试样进行激光强化试验,并使用不同的制孔工艺开孔,随后进行拉伸试验,试验后观察断口的疲劳源位置、孔壁质量,并测量孔壁粗糙度。试验研究表明,对于未进行激光冲击强化的试件,不同的制孔工艺对小孔件寿命无明显影响;对于激光冲击强化后的试件,使用不同的制孔工艺对小孔件寿命差异较大;因此在激光强化前后,制孔工艺对小孔件的疲劳寿命影响是不同的。     

Sensorless stepwise breakthrough detection technique for safe surgical drilling of bone

In bone surgery, drilling of bone without causing severe damage to tissue is a critical procedure. Particularly for skull, spine, and special kinds of orthopedic surgeries, the process of bone drilling requires high accuracy and precision since excessive drill protrusion can cause damage to nerves, blood vessels, and nearby organs. To enhance safety of drilling, a new breakthrough detection technique that does not require the installation of a sensor for force or torque measurement is proposed. This technique relies only on the measurement of current flowing through the motor of an electric drill to monitor drilling progress. By measuring the amount of current while executing stepwise drilling and applying a hysteresis thresholding algorithm, the breakthrough event can be effectively identified in real-time. Experimental tests of a drill prototype utilizing this scheme showed that breakthrough could be consistently detected. This prevents over drilling, enabling reliable drilling operation which can minimize tissue damage.     

钻孔刀具缠丝问题的专项改善与研究

为了保证钻削过程的正常进行,必须保证避免出现钻屑过长缠绕刀具的现象,钻屑不能及时被排除,导致孔壁质量无法保证。文章从钻屑的形成过程、刀具几何角度的设计、钻孔参数的优化三方面进行论述,彻底解决钻屑缠绕刀具的问题,为高质量的孔壁状态奠定了充实基础与有效保障。     

晶体硅片上激光打孔的研究

背面接触太阳电池越来越多地被人们关注,这种电池增加了使用激光器在硅片上打孔工艺。选用了半导体激光器作为光源在晶体硅片上进行打孔实验。通过调节激光器的功率、离焦量、脉冲重复频率等参数并分析其对打孔的影响。在激光打孔后,对硅片使用显微镜测试来分析打孔大小、形貌和损伤区,并优化打孔的参数。通过实验证实孔的入孔直径和出孔直径都随激光能量的增大而增大。随着离焦量的增大,出孔直径先增大后减小,且出孔直径越大时孔附近的破坏区域越小。脉冲重复频率的变化由于影响激光能量而影响孔径。另外,脉冲重复频率过大时,激光能量仍然比较大,但却打不穿硅片。     

Middle-ear structures contribute little to auditory perception of microwaves.

The contribution of the ossicles (middle-ear bones) to auditory perception of microwaves was evaluated by the brain-stem evoked response (BER). Amplitude and latency of BERs were recorded from guinea pigs that were stimulated at various intensities by acoustic pulses coupled to the auditory canal or via bone conduction, and by microwave pulses. Blocking of the external ear, middle-ear damping, and middle-ear destruction produced little change in the BERs that were elicited by microwave pulses. Results indicate that activity in the central auditory pathway as induced by pulsed microwaves only requires stimulation of the cochlea. Conduction of pressure waves through the bones of the calvarium appears to be the mechanism responsible in perception of pulsed microwaves.